UNITED STATES
 SECURITIES AND EXCHANGE COMMISSION
 Washington, D.C. 20549

 FORM 10-K

 (Mark One)

 ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934

 For the fiscal year ended December 31, 2024
 OR

 TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934

 For transition period from to
 Commission File Number 001-40791

 (Exact name of registrant as specified in its charter)

 Delaware

 86-3658454

 (State or other jurisdiction of
 incorporation or organization)

 (I.R.S. Employer
 Identification Number)

 60 Binney Street
 Cambridge, Massachusetts 02142
 ( 617) 675-7270
 (Address, including zip code, and telephone number, including area code, of registrant's principal executive offices)

 Securities registered pursuant to Section 12(b) of the Act:

 Title of each class
 Trading Symbol
 Name of each exchange on which registered

 Common Stock, par value $0.0001 per share
 TSVT
 The Nasdaq Stock Market LLC

 Securities registered pursuant to Section 12(g) of the Act: None

 Indicate by check mark if the registrant is a well-known seasoned issuer, as defined in Rule 405 of the Securities Act. Yes No
 Indicate by check mark if the registrant is not required to file reports pursuant to Section 13 or 15(d) of the Act. Yes No
 Indicate by check mark whether the Registrant (1) has filed all reports required to be filed by Section 13 or 15(d) of the Securities Exchange Act of 1934 during the preceding 12 months (or for such shorter period that the Registrant was required to file such reports), and (2) has been subject to such filing requirements for the past 90 days. Yes No
 Indicate by check mark whether the Registrant has submitted electronically every Interactive Data File required to be submitted pursuant to Rule 405 of Regulation S-T (§232.405 of this chapter) during the preceding 12 months (or for such shorter period that the Registrant was required to submit such files). Yes No
 Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer, a smaller reporting company or an emerging growth company. See the definitions of "large accelerated filer," "accelerated filer," "smaller reporting company" and "emerging growth company" in Rule 12b-2 of the Exchange Act.

 Large accelerated filer

 Accelerated filer

 Non-accelerated filer

 Smaller reporting company

 Emerging growth company

 If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act.

 Indicate by check mark whether the registrant has filed a report on and attestation to its management's assessment of the effectiveness of its internal control over financial reporting under Section 404(b) of the Sarbanes-Oxley Act (15 U.S.C. 7262(b)) by the registered public accounting firm that prepared or issued its audit report.
 If securities are registered pursuant to Section 12(b) of the Act, indicate by check mark whether the financial statements of the registrant included in the filing reflect the correction of an error to previously issued financial statements.
 Indicate by check mark whether any of those error corrections are restatements that required a recovery analysis of incentive-based compensation received by any of the registrant's executive officers during the relevant recovery period pursuant to §240.10D-1(b).
 Indicate by check mark whether the registrant is a shell company (as defined in Rule 12b-2 of the Exchange Act): Yes No
 The aggregate market value of common stock held by non-affiliates of the registrant based on the closing price of the registrant's common stock as reported on the Nasdaq Global Select Market on June 30, 2024, the last business day of the registrant's most recently completed second quarter was $ 198,251,396.

 The number of shares of registrant's common stock outstanding as of March 20, 2025, was 52,338,383.
 DOCUMENTS INCORPORATED BY REFERENCE
 The registrant intends to file either (i) a definitive proxy statement pursuant to Regulation 14A relating to the 2025 Annual Meeting of Stockholders, or (ii) an amendment to his Annual Report on Form 10-K/A, in either case within 120 days of the end of the registrant's fiscal year ended December 31, 2024. Portions of such definitive proxy statement are incorporated by reference into Part III of this Annual Report on Form 10-K to the extent stated herein.

 Page

 Item 1. Business

 Item 1A. Risk Factors

 Item 1B. Unresolved Staff Comments

 Item 1C. Cybersecurity

 Item 2. Properties

 Item 3. Legal Proceedings

 Item 4. Mine Safety Disclosures

 Item 5. Market for Registrant's Common Equity, Related Stockholder Matters and Issuer Purchases of Equity Securities

 Item 6. Reserved

 Item 7. Management's Discussion and Analysis of Financial Condition and Results of Operations

 Item 7A. Quantitative and Qualitative Disclosures About Market Risk

 Item 8. Financial Statements and Supplementary Data

 Item 9. Changes in and Disagreements With Accountants on Accounting and Financial Disclosure

 Item 9A. Controls and Procedures

 Item 9B. Other Information

 Item 9C. Disclosure Regarding Foreign Jurisdictions that Prevent Inspections

 Item 10. Directors, Executive Officers and Corporate Governance

 Item 11. Executive Compensation

 Item 12. Security Ownership of Certain Beneficial Owners and Management and Related Stockholder Matters

 Item 13. Certain Relationships And Related Person Transactions and Director Independence

 Item 14. Principal Accounting Fees and Services

 Item 15. Exhibit and Financial Statement Schedules

 Item 16. Form 10–K Summary

 Signatures

 i

 SPECIAL NOTE REGARDING FORWARD-LOOKING STATEMENTS
 This Annual Report on Form 10-K, or this Annual Report, contains forward-looking statements that involve risks and uncertainties. We make such forward-looking statements pursuant to the safe harbor provisions of the Private Securities Litigation Reform Act of 1995 and other federal securities laws. All statements other than statements of historical facts contained in this Annual Report are forward-looking statements. In some cases, you can identify forward-looking statements by terminology such as "may", "will", "should", "expects", "intends", "plans", "anticipates", "believes", "estimates", "predicts", "potential", "continue" or the negative of these terms or other comparable terminology. These forward-looking statements include, but are not limited to, statements about:
 • the Agreement and Plan of Merger we entered into on March 10, 2025 with Bristol-Myers Squibb Company ("BMS") and Daybreak Merger Sub Inc. (the "BMS Merger Agreement"), and the risks and uncertainties and potential impacts and timing relating thereto;
 • our plans and the plans of BMS, for the continued commercialization of Abecma;
 • our ability to finance our operations and business initiatives and obtain funding for such activities;
 • the perceived therapeutic benefits of Abecma and the potential indications and market opportunities therefor;
 • our plans with respect to the development, manufacture or sale of Abecma and the associated timing thereof, including the design and results of pre-clinical and clinical studies;
 • sourcing supplies for the materials used to manufacture Abecma;
 • the safety profile and related adverse events of Abecma;
 • our ability to compete with other companies that are or may be developing or selling products that are competitive with Abecma;
 • U.S. and foreign regulatory requirements for Abecma, including any post-approval development and regulatory requirements, and the ability of Abecma to meet such requirements;
 • our ability to attract and retain key employees needed to execute our business plans and strategies and our expectations regarding our ability to manage the impact of any loss of key employees;
 • our ability to obtain and maintain intellectual property protection for Abecma and the strength thereof;
 • the anticipated benefits of the sale of our oncology and autoimmune research and development programs (including our bbT369 program in b-NHL, SC-DARIC33 in AML, MUC16 in ovarian cancer, MAGE A4, autoimmune, and several unnamed targets), clinical manufacturing capabilities, and related platform technologies to Regeneron Pharmaceuticals, Inc., or "Regeneron", which we refer to as the "Regeneron Transaction", and the sale of our megaTAL and hemophilia A programs to Novo Nordisk A/S, or "Novo", which we refer to as the "Novo Transaction";
 • our future financial performance, including estimates of our future revenues, expenses, cash flows, profitability, tax obligations, capital requirements and our needs for additional financing, liquidity sources, real estate need and concentration of voting control, as well as the timing and drivers thereof, and internal control over financial reporting;
 • the status of government regulation in the life sciences industry, particularly with respect to healthcare reform;
 • potential indemnification liabilities we may owe to bluebird bio, Inc., or "bluebird bio", after the separation;
 • the impact of inflation rates on our business, financial condition and results of operation;
 ii

 • the fluctuation of the market price of our shares; and
 • trends and challenges in our current and potential markets.
 See "Risk Factors" for a further description of these and other factors. Any forward-looking statements in this Annual Report reflect our current views with respect to future events and with respect to our future financial performance, and involve known and unknown risks, uncertainties and other factors that may cause our actual results, performance or achievements to be materially different from any future results, performance or achievements expressed or implied by these forward-looking statements. Factors that may cause actual results to differ materially from current expectations include, among other things, those described under Part I, Item 1A, "Risk Factors" and elsewhere in this Annual Report. Given these uncertainties, you should not place undue reliance on these forward-looking statements. Except as required by law, we assume no obligation to update or revise these forward-looking statements for any reason, even if new information becomes available in the future.
 All of our forward-looking statements are as of the date of this Annual Report only. In each case, actual results may differ materially from such forward-looking information. We can give no assurance that such expectations or forward-looking statements will prove to be correct. An occurrence of or any material adverse change in one or more of the risk factors or risks and uncertainties referred to in this Annual Report or included in our other public disclosures or our other periodic reports or other documents or filings filed with or furnished to the Securities and Exchange Commission, or the SEC, could materially and adversely affect our business, prospects, financial condition and results of operations. Except as required by law, we do not undertake or plan to update or revise any such forward-looking statements to reflect actual results, changes in plans, assumptions, estimates or projections or other circumstances affecting such forward-looking statements occurring after the date of this Annual Report, even if such results, changes or circumstances make it clear that any forward-looking information will not be realized. Any public statements or disclosures by us following this Annual Report that modify or impact any of the forward-looking statements contained in this Annual Report will be deemed to modify or supersede such statements in this Annual Report.
 We may from time to time provide estimates, projections and other information concerning our industry, the general business environment, and the markets for certain diseases, including estimates regarding the potential size of those markets and the estimated incidence and prevalence of certain medical conditions. Information that is based on estimates, forecasts, projections, market research or similar methodologies is inherently subject to uncertainties, and actual events, circumstances or numbers, including actual disease prevalence rates and market size, may differ materially from the information reflected in this Annual Report. Unless otherwise expressly stated, we obtained this industry, business information, market data, prevalence information and other data from reports, research surveys, studies and similar data prepared by market research firms and other third parties, industry, medical and general publications, government data, and similar sources, in some cases applying our own assumptions and analysis that may, in the future, prove not to have been accurate.

 iii

 Summary of the Material and Other Risks Associated with Our Business
 • The proposed acquisition by BMS is subject to a number of conditions beyond our control. Failure to complete the proposed acquisition within the expected time frame, or at all, could have a material adverse effect on our business, operating results, financial condition and our stock price.
 • We are a cell therapy company with a limited operating history as an independent company. To date, we have not recognized any revenues from the sale of products by us. Our revenues have been derived from out-licensing arrangements and collaboration arrangements, including the collaboration revenue derived from sales of Abecma by BMS. We may never become profitable.
 • Our business has incurred significant losses and we anticipate that we will incur continued losses for the near future.
 • We may need to raise additional funding to advance Abecma, which may not be available on acceptable terms, or at all. Failure to obtain capital when needed may force us to delay, limit or terminate development or commercialization efforts or other operations. Raising additional capital may dilute our existing stockholders, restrict our operations or cause us to relinquish valuable rights.
 • Our strategic realignment to focus on the development and commercialization of Abecma may not be as successful as anticipated, fail to achieve the anticipated cost savings, and cause disruptions in our business that could make it difficult to achieve our strategic objectives.
 • We have undertaken internal restructuring activities in the past, and may do so again in the future. The assumptions underlying these activities may prove to be inaccurate, or we may fail to achieve the expected benefits.
 • If the market opportunities for Abecma or any future approved products are smaller than we believe they are, and if we are not able to successfully identify patients and achieve significant market share, our revenues may be adversely affected and our business may suffer.
 • Patients receiving Abecma may experience serious adverse events, including neurotoxicity and cytokine release syndrome. Serious adverse events or undesirable side effects associated with Abecma may impact commercial sales, which will significantly harm our business, financial condition and prospects.
 • We are dependent on BMS for the successful development, commercialization and manufacture of Abecma. If BMS does not devote sufficient resources to the commercialization, manufacture and further development of Abecma, is unsuccessful in its efforts, or chooses to terminate its agreements with us, our business will be materially harmed.
 • We rely on third parties to conduct some or all aspects of our lentiviral vector production, drug product manufacturing, and testing, and these third parties may not perform satisfactorily.
 • If we are unable to obtain or protect intellectual property rights related to our approved product or future product candidates, we may not be able to compete effectively in our markets.
 iv

 Item 1. Business
 Overview
 We are a cell therapy company focused, together with our partner, BMS, on the commercialization and delivery of Abecma (idecabtagene vicleucel, or ide-cel), the first chimeric antigen receptor, or CAR, T cell therapy approved by the U.S. Food and Drug Administration, to multiple myeloma patients in the United States. Abecma was approved by the FDA in March 2021 for the treatment of adults with multiple myeloma who have received at least four prior lines of therapy, including an immunomodulatory agent, a proteasome inhibitor and an anti-CD38 (cyclic ADP ribose hydrolase) monoclonal antibody. On April 4, 2024 the U.S. Food and Drug Administration (the "FDA") approved Abecma for the treatment of adult patients with relapsed or refractory multiple myeloma after two or more prior lines of therapy, including an immunomodulatory agent, a proteasome inhibitor, and an anti-CD38 monoclonal antibody.
 In recent years, growing understanding of cancer cell metabolism and genomics, as well as of the body's immune response to tumor cells, has led to the development of new classes of therapies against cancer targets and pathways that have dramatically reshaped the treatment landscape. The advent of immunotherapy, particularly engineered cell therapies, has offered the potential to move past the treatment paradigm of maintenance of cancer as a "chronic" disease. Few curative therapies, however, exist and, in some settings, such as solid tumors, current approaches do not offer significant depth or durability of outcome for most cancer types and patients. Monotherapies have historically been of limited efficacy in cancer, and drugs are typically combined to deliver an outsized effect relative to the action of any of the individual components, with one potential advantage of combination therapies being the ability to address the heterogeneity of single target expression and/or mechanisms for relapse and resistance specific to a particular mechanism or target.
 In January 2024, we began undertaking a strategic realignment to focus on the development and commercialization of Abecma. In connection with the strategic realignment, we entered into the Regeneron Transaction to sell to Regeneron substantially all of the assets related to our solid tumor and other oncology and autoimmune cell therapy programs, including our bbT369 program in b-NHL, SC-DARIC33 in AML, MUC16 in ovarian cancer, MAGE-A4, autoimmune, and several unnamed targets. Upon closing of the Regeneron Transaction on April 1, 2024, Regeneron assumed all of the ongoing program, infrastructure and personnel costs related to these programs. Also, as part of our strategic realignment, in June 2024, we announced the completion of the Novo Transaction, pursuant to which Novo acquired our program for the research, development, manufacture, regulatory approval, and commercialization of gene therapy products exploiting the megaTAL Platform that is directed to the treatment, diagnosis, and prevention of hemophilia.
 The Proposed BMS Transaction
 On March 10, 2025, we entered into the BMS Merger Agreement, pursuant to which, and upon the terms and subject to the conditions thereof, a wholly-owned subsidiary of BMS will commence a tender offer to purchase all of our outstanding common stock at a cash price of $5.00 per share, less any applicable withholding taxes and without interest. In the event the tender offer conditions are satisfied and the tender offer is closed, the parties will consummate a merger that will result in our company being a wholly owned subsidiary of BMS. Upon completion of the merger, we will no longer be a publicly traded company, and the listing of our common stock on Nasdaq will have been terminated. Refer to Note 20 to our Consolidated Financial Statements regarding the BMS Merger Agreement, the transactions provided for thereunder, and the various conditions to closing the transaction. Refer to Item 1A. "Risk Factors" for a summary of risks related to the transaction.

 Our Strengths
 We work closely with our partner, BMS, to manufacture, sell, and deliver Abecma to U.S. multiple myeloma patients.
 Commercial and manufacturing support: We have partnered with BMS in commercializing Abecma in the US and have a unique understanding of the market and supply dynamics required to deliver an autologous CAR T treatment. This knowledge allows us to analyze commercial and supply chain data and provide business analysis that informs decision making and improves business outcomes.
 Quality control and testing: From having developed the lentiviral vector used in Abecma, we have cultivated a best-in-class Quality organization that performs complex tests that enable lentiviral vector release and subsequent use in the manufacturing of Abecma.
 Who We Are
 Our people form the most vital core of our company. We have assembled a diverse group of subject matter experts to execute our strategic plan. We have a passionate and energized team with a bold culture of innovation, focused on unleashing the full potential of Abecma and other future therapeutic approaches that we believe may have the potential to transform the lives of patients with cancer and other debilitating diseases. Our executive leadership team has a wide range of experience in the biopharmaceutical industry with deep experience and expertise in building high growth and disruptive companies.
 Our Strategy
 Together with BMS, we are focused on supporting the commercial growth of Abecma. This includes educating physicians on treatment sequencing and the emerging data supporting the use of BCMA-directed CAR Ts before other BCMA-targeted therapies, and competitively differentiating Abecma's real-world safety, efficacy and product reliability and predictability profile. We continue to support the quality control testing of the lentiviral vector, or LVV, manufacturing for Abecma.
 Abecma offers significant clinical benefits and long-term potential in the treatment of patients with multiple myeloma and our strategy is to exclusively focus on the development and commercialization of Abecma through our collaboration with BMS.
 Background
 Cancer is a leading cause of death worldwide. It is characterized by the uncontrolled growth of cells that have the ability to evade recognition by the immune system's surveillance. Despite advances over the years, there remains a high unmet medical need for additional products and treatments, especially for patients with recurrent tumors or cancer types that are resistant to current therapeutic options.
 The advent of immunotherapy, and specifically engineered cell therapies, which direct the body's natural immune response against cancer cells, has offered the potential to move past the prior treatment paradigm. Compelling efficacy data in cancers with historically bleak outcomes, with patients experiencing deep responses lasting for extended periods of time across multiple indications, showed the potential for engineered cell therapy.
 Our Programs
 Multiple Myeloma
 Multiple myeloma is a blood cancer caused by malignant plasma cells and typically originates in the bone marrow. In the United States, approximately 36,000 new cases of multiple myeloma are estimated to have been diagnosed in 2024. Despite advances in treatment, multiple myeloma remains an aggressive and incurable disease characterized by periods of remission and relapse. Most patients experience relapse following initial therapies, and depth and duration of response as well as survival outcomes decrease with each successive treatment. No standard of care has been established for patients who have disease progression despite receiving the three main classes of

 myeloma therapy (immunomodulatory drugs, proteasome inhibitors, and anti-CD38 antibodies), and outcomes are poor, with very low response rates (20% to 40%), a median progression-free survival of three to four months, and a median overall survival of eight to nine months. Through our collaboration with BMS, Abecma (ide-cel) is our lead program in multiple myeloma. The terms of our arrangements with BMS are described more fully below under "Strategic Collaborations."
 Abecma
 Lentiviral vectors deliver the genetic cargo with the potential to program a patient's own T cells to recognize specific proteins or protein fragments on the surface of cancer cells to kill the cancer cells. Abecma uses a LVV to deliver a CAR, with the potential to program a patient's own T cells to recognize the plasma cell specific B cell maturation antigen, or BCMA, protein on the cell surface. We believe BCMA is an ideal target in multiple myeloma, or MM, since it is near universally and abundantly expressed on both normal and malignant plasma cells, independent of disease stage, and its expression is absent from other normal tissues resulting in a robust therapeutic window. We have developed, patented or licensed critical technologies to the generation of Abecma. To recognize BCMA as a target, we performed multiple extensive screening campaigns to identify the ideal binder and CAR construct to ensure both low tonic signaling in the absence of antigen and robust efficacy in in vitro and in vivo models of MM. We have secured an exclusive license to the selected binder used in Abecma as well as several back up constructs. The Abecma CAR construct exploits both CD3z and 4-1BB signaling domains believed to result in a more progressive proliferation response that may give the CAR T cells improved persistence over CD28 based co-stimulation. The persistence of functional CAR T cells is likely a critical determinant of both the depth and the duration of response and as such Abecma is designed to achieve these key characteristics. We have developed improved methods for the generation and purification of LVVs, including suspension-based LVVs, which enable the generation of the vector used in drug product manufacture at significantly greater scale and lower cost. We have demonstrated comparability of the suspension-based LVV manufacturing process and the Abecma suspension Lentiviral Vector (sLVV) Prior Approval Supplement (PAS) was approved by the FDA in March 2024. Our drug product manufacturing process was designed for simplicity and reproducibility. Our peripheral blood mononuclear cells, or PBMC,-based drug product manufacturing process was designed for simplicity and reproducibility and employs a centralized manufacturing site model.
 Abecma and our collaboration with BMS.In March 2021, Abecma was initially approved by the FDA in the United States for the treatment of adults with multiple myeloma who have received at least four prior lines of therapy, including an immunomodulatory agent, a proteasome inhibitor, and an anti-CD38 monoclonal antibody. On April 4, 2024 the FDA approved Abecma for the treatment of adult patients with relapsed or refractory multiple myeloma after two or more prior lines of therapy, including an immunomodulatory agent, a proteasome inhibitor, and an anti CD38 monoclonal antibody. Abecma is a first-in-class B cell maturation antigen, or BCMA, CAR T therapy for the treatment of multiple myeloma, and represents our first oncology product candidate that has progressed from research programs, through clinical development to approval and commercialization, together with our collaboration partner, BMS. Revenue from sales of Abecma in the United States in 2024 equaled $242 million, which is shared equally between us and BMS along with the related cost of sales and other commercialization costs. Together with BMS, our goal is to enable more patients to access the treatment. To help achieve that goal, we educate physicians on treatment sequencing and the emerging data supporting the use of BCMA-directed CAR Ts before other BCMA-targeted therapies, and competitively differentiating Abecma's real-world safety, efficacy and product reliability and predictability profile.
 As the first CAR T cell therapy approved for multiple myeloma, Abecma is a potentially transformative, single-infusion, individualized treatment that offers patients who have limited effective treatment options the potential for long-term disease control. The approval of Abecma in the United States was based on positive results from the pivotal KarMMa study. In the KarMMa study, the overall response rate was 73%, and 33% of patients achieved a complete response. Onset of response was rapid with a median time to first response of one month. Median duration of response was 10.7 months and 19 months for those who achieved a complete response. Abecma has a well-established safety profile with mostly low-grade cytokine release syndrome (Grade 3: 5%; grade 2 events: 84%) and neurologic toxicities (Grade 3: 3%; grade 2 events: 18%) with early onset and resolution. Results from the KarMMa study were published in the February 24, 2021 issue of the New England Journal of Medicine. The 2024 approval of Abecma after two of more lines of therapy was based on positive results from the pivotal KarMMa-3

 study. In the KarMMa-3 study, myeloma patients who had received 2-4 prior lines of therapy were randomly assigned in a 2:1 ratio to Abecma or one of five standard regimens. Abecma showed a significant improvement in progression free survival (13.3 vs 4.4 months), overall response rates (71% vs 42%), as well as complete response rates (39% vs 5%) versus standard of care. Safety results were consistent with the KarMMa study. Results from the KarMMa-3 study were published in the February 10, 2023 issue of the New England Journal of Medicine. The FDA and EMA have granted Orphan Drug status to ide-cel for the treatment of patients with relapsed and refractory multiple myeloma. The EMA has granted PRIME eligibility to ide-cel for relapsed and refractory multiple myeloma. On September 25, 2024, following a joint decision we made with BMS earlier that week, we announced the discontinuation of enrollment in our ongoing Phase 3 KarMMa-9 study evaluating Abecma with lenalidomide maintenance versus lenalidomide maintenance alone in patients with newly diagnosed multiple myeloma who have suboptimal response to autologous stem cell transplant.
 Manufacturing
 BMS is responsible for all Abecma commercial vector manufacturing within and outside of the United States. In June 2023, we assigned the Commercial Supply Agreement with National Resilience, Inc., or "Resilience" to BMS and BMS assumed responsibilities for manufacturing ide-cel suspension lentiviral vector.
 Strategic Collaborations
 Subsequent to the Regeneron and Novo Transactions, the Company's remaining strategic collaboration is with BMS.
 bluebird bio began a collaboration with BMS in 2013 under a broad-ranging Master Collaboration Agreement with Celgene Corporation (now BMS following its acquisition of Celgene in November 2019), or the BMS Collaboration Agreement. bluebird bio continued that collaboration with a series of agreements. In connection with our separation from bluebird bio, bluebird bio assigned to us all of the agreements relating to its collaboration with BMS.
 Amended BMS Collaboration Agreement
 In March 2013, bluebird bio entered into the BMS Collaboration Agreement to discover, develop and commercialize potentially disease-altering cell therapies in oncology. bluebird bio concurrently entered into a Platform Technology Sublicense Agreement, or the "Sublicense Agreement" with BMS pursuant to which bluebird bio obtained a sublicense to certain intellectual property from BMS, originating under BMS's license from Baylor College of Medicine, for use in the collaboration. For further information on this agreement and amendments related to this agreement, refer to our prior year Annual Reports on Form 10-K.
 BMS Ide-cel related agreements
 In February 2016, BMS exercised its option to obtain an exclusive worldwide license to develop and commercialize ide-cel, the first product candidate under the Amended BMS Collaboration Agreement, pursuant to an executed license agreement, or the "Ide-cel License Agreement", and paid the associated $10.0 million option fee. Pursuant to the Ide-cel License Agreement, BMS was responsible for development and related funding of ide-cel after the substantial completion of the Phase 1 clinical trial. bluebird bio was responsible for the manufacture of vector and associated payload throughout development and, upon BMS's request, throughout commercialization, the costs of which were reimbursable by BMS in accordance with the terms of the Amended and Restated Co-Development, Co-Promote and Profit Share Agreement, as further described below. BMS was responsible for the manufacture of drug product throughout development and commercialization. Under the Ide-cel License Agreement, bluebird bio was eligible to receive (i) U.S. milestones of up to $85.0 million for the first indication to be addressed by ide-cel and royalties for U.S. sales of ide-cel and (ii) ex-U.S. milestones of up to $55.0 million and royalties for ex-U.S. sales of ide-cel.
 In March 2018, bluebird bio elected to co-develop and co-promote ide-cel within the United States pursuant to the execution of the Amended and Restated Co-Development, Co-Promote and Profit Share Agreement, or the "Ide-cel CCPS", which replaced the Ide-cel License Agreement. As a result, we will share equally in all profits and losses

 related to developing, commercializing and manufacturing ide-cel within the United States and have the right to participate in the development and promotion of ide-cel in the United States. BMS is responsible for the costs incurred to manufacture vector and associated payload for use outside of the United States, plus a markup. As a result of electing to co-develop and co-promote ide-cel within the United States, the milestones and royalties payable under the Ide-cel License Agreement were adjusted. Under the Ide-cel CCPS, bluebird bio was eligible to receive a $10.0 million milestone related to the development of ide-cel in the United States and, for the first indication to be addressed by ide-cel, ex-U.S. regulatory and commercial milestones of up to $60.0 million. Under the Ide-cel CCPS, the $10.0 million milestone related to the development of ide-cel in the United States was achieved in the second quarter of 2019 and subsequently paid by BMS.
 May 2020 Amendment to Ide-cel agreement
 In May 2020, the First Amendment to the Amended and Restated Co-Development, Co-Promote and Profit Share Agreement, as amended, or the "Amended Ide-cel CCPS" was executed. Under the Amended Ide-cel CCPS, the parties will continue to share equally in all profits and losses related to developing, commercializing and manufacturing ide-cel within the United States. The Amended Ide-cel CCPS changed our responsibilities with respect to manufacturing activities. Under the Amended Ide-cel CCPS, BMS assumed the contract manufacturing agreements related to ide-cel adherent lentiviral vector. Over time, BMS also assumed responsibility for manufacturing ide-cel suspension lentiviral vector outside of the United States, while we remained responsible for manufacturing ide-cel suspension lentiviral vector in the United States. In June 2023, we executed the Second Amendment to the Amended Ide-cel CCPS, pursuant to which we assigned the Commercial Supply Agreement with Resilience to BMS and BMS assumed responsibilities for global manufacturing ide-cel suspension lentiviral vector.
 The May 2020 Amendments relieved BMS of its obligations to pay us for future ex-U.S. milestones and royalties on ex-U.S. sales for each of ide-cel and bb21217 in exchange for an up-front, non-refundable, non-creditable payment of $200.0 million, which represents the aggregate of the probability-weighted, net present value of the future ex-U.S. milestones and royalties on ex-U.S. sales for each of ide-cel and bb21217. In addition, the parties are released from future exclusivity related to BCMA-directed T cell therapies. There are no remaining milestones or royalties under the Amended Ide-cel CCPS. The Amended Ide-cel CCPS will continue on a country-by-country basis until there are no more payments owed by either party on ide-cel in such country, unless earlier terminated (a) by mutual consent of the parties, (b) by us following a material breach by BMS that remains uncured after a specified period, (c) by us at our discretion, following a specified notice period, (d) by BMS following a material breach by us that remains uncured after a specified period, (e) by BMS at its discretion, following a specified notice period, or (f) pursuant to certain other negotiated termination provisions.
 In March 2021, the FDA approved the marketing of Ide-cel as Abecma in the United States for the treatment of adult patients with relapsed or refractory multiple myeloma after four or more prior lines of therapy, including an immunomodulatory agent, a proteasome inhibitor, and an anti-CD38 monoclonal antibody. In April 2024, the FDA approved Abecma for the treatment of adult patients with relapsed or refractory multiple myeloma after two or more prior lines of therapy. Under the Amended Ide-cel CCPS, BMS is primarily responsible for the commercialization of Abecma.
 License Agreements
 Biogen. In August 2014, bluebird bio entered into a license agreement with Biogen, pursuant to which bluebird bio co-exclusively licensed certain patents and patent applications directed towards aspects of T cell-based products that target BCMA. In connection with the separation, bluebird bio assigned this license agreement to us. Biogen retains the right to practice and use the licensed patents in the licensed field and territory. We have the right to grant sublicenses to third parties, subject to certain conditions. We are obligated to pay Biogen a percentage (in the low single digits) of net sales of products covered by the in-licensed intellectual property, including Abecma, as a royalty. Additionally, we are subject to certain development and regulatory milestone obligations and must report on our progress in achieving those milestones on a periodic basis. We may be obligated to pay up to $23.0 million in the aggregate for each licensed product upon the achievement of remaining milestones. We may unilaterally terminate the license agreement at any time with prior written notice to Biogen. Either party may terminate the license in the event of the other party's material breach upon notice and following an opportunity for the breaching

 party to cure. Either party may also terminate the agreement in the event bankruptcy proceedings are opened against the other party and are not dismissed within a specified period of time. Absent early termination, the agreement will automatically terminate upon the expiration of all patent rights covered by the agreement or ten years from the date of first commercial sale of a licensed product, whichever is later. The longest lived patent rights licensed to us are in a U.S. patent, currently expected to expire in 2032.
 NIH. In August 2015, bluebird bio entered into a license agreement with the NIH, pursuant to which bluebird bio exclusively licensed certain patents and patent applications directed towards aspects of T cell-based products that target BCMA. In connection with the separation, bluebird bio assigned this license agreement to us. Any patents within this portfolio that have issued or may yet issue would have an expected statutory expiration date in 2033 to 2034. The NIH retains the right to practice the intellectual property licensed under the agreement on behalf of the government of the United States. We have the right to grant sublicenses to third parties, subject to certain conditions. For each such sublicense we grant we must pay the NIH a fee. Upon commercialization of our products covered by the in-licensed intellectual property, which includes Abecma, we will be obligated to pay the NIH a percentage of annual net sales as a royalty in the low single digits. We are subject to a domestic production requirement that licensed products, such as Abecma, sold or used in the U.S. or produced through use of the licensed processes must be manufactured substantially in the U.S., unless a waiver is obtained in advance from the NIH. Additionally, we are subject to certain development and regulatory milestone obligations and must report on our progress in achieving those milestones on a periodic basis. We may be obligated to pay up to $9.7 million in the aggregate for a licensed product upon the achievement of these milestones. We may unilaterally terminate the license agreement at any time with prior written notice to the NIH. The NIH may terminate the license in the event of our material breach upon notice and following an opportunity for us to cure the material breach. The NIH may also terminate the agreement in the event bankruptcy proceedings are opened against us and are not dismissed within a specified period of time. Absent early termination, the agreement will automatically terminate upon the expiration of the patent rights covered by the agreement. The longest lived patent rights licensed to us under the Agreement are currently expected to expire in 2034.
 bluebird bio. We entered into an intellectual property license agreement in connection with the separation with bluebird bio pursuant to which each party granted a license to certain intellectual property and technology. bluebird bio granted us a perpetual, worldwide, non-exclusive, royalty-free, fully paid-up license to certain intellectual property to allow us to use such intellectual property in connection with our ongoing and future research and development activities and product candidates. We granted to bluebird bio a perpetual, worldwide, non-exclusive, royalty-free, fully paid-up license (or, as the case may be, sublicense) to certain intellectual property for use in bluebird bio's existing products and product candidates. Such licenses between the parties generally allow current or future uses of the intellectual property in connection with each party's respective fields.
 Competition in the Multiple Myeloma Market
 The current standard of care for multiple myeloma includes IMiDs (e.g., thalidomide, lenalidomide, pomalidomide), proteasome inhibitors (e.g., bortezomib, carfilzomib, ixazomib), monoclonal antibodies (e.g., daratumamab, isatuximab, elotuzumab), cytotoxic agents, and HSCT. There are several companies developing autologous T cell therapies for relapsed and refractory multiple myeloma that use a similar autologous ex vivo approach, but a different target antigen or antigens, BCMA single-chain variable fragment or, we believe, cell processing techniques. The most advanced of these programs include: ciltacabtagene autoleucel, an anti-BCMA CAR T cell therapy marketed as Carvykti that was initially approved by the FDA in February 2022 (Janssen in collaboration with Legend Biotech); a CAR T-ddBCMA cell therapy in clinical development (pivotal Phase 2 iMMagine-1 and Phase 3 iMMagine-3) jointly developed by Arcellx in partnership with Kite, and an anti-GPRC5D CAR-T in clinical development by BMS (pivotal Phase 2 QUINTESSENTIAL). There are a number of other CAR T cell therapies in various stages of clinical development in myeloma. In addition to these autologous T cell-based approaches, several companies have early phase clinical studies for allogeneic CAR-T cell therapies including: Allogene Therapeutics, Poseida, Caribou, and Legend Biotech, among others. There are also other therapies using similar or novel modalities being developed by several groups, including multiple bispecific T cell engagers and specific antibody therapies, such as antibody-drug conjugates, or ADCs. In October 2022, the FDA approved Tecvayli (teclistamab, first-in-class BCMAxCD3 bispecific antibody) for patients with at least four prior therapies in relapsed and refractory multiple myeloma becoming the first treatment option with this modality to gain approval in

 the US. Two other BCMA-directed bispecific antibodies are Pfizer's Elrexfio (elranatamab), which was approved in 2023, and Regeneron's linvoseltamab, which is expected to be approved in 2025. In addition to Tecvayli, another bispecific antibody developed by Janssen, Talvey (talquetemab, first-in-class GPRC5DxCD3), was approved in 2023. After GSK noted the failure of the Phase 3 confirmatory DREAMM-3 study in 3L+ relapsed and refractory multiple myeloma, following the request of the FDA, GSK announced plans for full market withdrawal of Blenrep (BCMA targeting ADC). GSK continues to develop Blenrep, and has refiled for approval based on data from the positive Phase 3 DREAMM-7 and DREAMM-8 studies that read out in 2024.
 Intellectual Property
 We strive to protect and enhance the proprietary technology, inventions, and improvements that are commercially important to the development of our business, including seeking, maintaining, and defending patent rights, whether developed internally or licensed from third parties. We also rely on know-how, continuing technological innovation and in-licensing opportunities to develop, strengthen, and maintain our proprietary position in the fields of oncology that may be important for the development of our business. Additionally, we rely on regulatory protection afforded through data exclusivity, market exclusivity, and patent term extensions and supplementary protection certificates where available.
 Our commercial success may depend in part on our ability to obtain and maintain patent and other proprietary protection for commercially important technology, inventions and know-how related to our business; defend and enforce our patents; preserve the confidentiality of our trade secrets, if applicable; and operate without infringing the valid enforceable patents and proprietary rights of third parties. Our ability to stop third parties from making, using, selling, offering to sell, or importing our products may depend on the extent to which we have valid and enforceable patent rights or trade secrets that cover these activities. With respect to both licensed and company-owned intellectual property, we cannot be sure that patents will be granted with respect to any of our pending patent applications or with respect to any patent applications filed by us in the future, nor can we be sure that any of our existing patents or any patents that may be granted to us in the future will be commercially useful in protecting our commercial products and methods of manufacturing the same.
 We have developed or in-licensed numerous patents and patent applications and possess substantial know-how relating to the development and commercialization of oncology products. Our proprietary intellectual property, including patent and non-patent intellectual property, is generally directed to, for example, certain cell therapies, chimeric antigen receptors, genes, transgenes, processes to manufacture our approved product and product candidates and other proprietary technologies and processes related to our approved product and product candidates.
 Our objective is to continue to protect our portfolio of patents and patent applications. Examples of the products and technology areas covered by our intellectual property portfolio are described below. From time to time, we also evaluate opportunities to sublicense our portfolio of patents and patent applications that we own or exclusively license, and we may enter into such licenses from time to time.
 While we maintain patents and patent applications in important foreign markets, such as in Europe, China, and Japan, we do not consider our patent portfolio outside of the United States to be material to 2seventy bio at this time. With respect to the patent portfolios for our commercial-stage product Abecma, development and commercialization rights have been exclusively licensed to BMS in exchange for an up-front payment. As a consequence, 2seventy bio will not receive royalties on sales of ide-cel outside of the United States.
 Abecma and Other BCMA-related IP
 The multiple myeloma program includes the patent portfolios described below. These rights were assigned or sublicensed to us pursuant to the intellectual property license agreement and other agreements that we entered into with bluebird bio in connection with the separation.
 • Biogen. The in-licensed Biogen Inc. (formerly Biogen Idec MA Inc.; referred to herein as Biogen) patent portfolio, contains patents and patent applications directed toward aspects of T cell-based products that target BCMA. We expect the issued composition of matter patents to expire from approximately 2024-2032 (excluding possible patent term extensions). Further, we expect any other patents in this portfolio, if issued,

 and if the appropriate maintenance, renewal, annuity or other governmental fees are paid, to expire from approximately 2024-2030 (worldwide, excluding possible patent term extensions).
 • NIH. The in-licensed patent portfolio from National Institutes of Health, or NIH, contains patents and patent applications directed towards aspects of chimeric antigen receptor-based immunotherapies that target BCMA. We expect the issued composition of matter and methods patents to expire from approximately 2033-2034 (excluding possible patent term extensions). We expect any other patents in this portfolio, if issued, and if the appropriate maintenance, renewal, annuity or other governmental fees are paid, to expire in approximately 2033 (worldwide, excluding possible patent term extensions).
 •2seventy bio IP. The owned patent portfolio contains patents and patent applications directed to certain specific compositions of matter and methods for generating CAR T cells.
 As of February 1, 2025, nine patent families of U.S. non-provisional applications, corresponding foreign applications, and associated issued patents related to CAR composition, methods of manufacture, compositions for detection and methods of treatment. We expect the issued composition of matter and methods patents to expire in approximately 2035 (worldwide, excluding possible patent term extensions). We expect any other patents, if issued from the pending patent applications or a corresponding national stage application, if applicable, and if the appropriate maintenance, renewal, annuity or other governmental fees are paid, to expire from approximately 2035-2040 (worldwide, excluding possible patent term extensions).
 Lentiviral Platform (e.g., Vectors, Manufacturing, and Cell Therapy Products)
 As of February 1, 2025, the lentiviral platform includes one patent family described below. These rights were assigned or sublicensed to us pursuant to the intellectual property license agreement and other agreements that we entered into with bluebird bio in connection with the separation.
 •2seventy bio IP. As of February 1, 2025, we owned one patent family of U.S. non-provisional applications and corresponding foreign applications, related to vector manufacturing. We expect any composition of matter or methods patents, if issued from a pending patent application or a corresponding national stage application, if applicable, and if the appropriate maintenance, renewal, annuity or other governmental fees are paid, to expire in approximately 2042 (worldwide, excluding possible patent term extensions).
 The term of individual patents depends upon the legal term of the patents in the countries in which they are obtained. In most countries in which we file, the patent term is 20 years from the date of filing the non-provisional application. In the United States, a patent's term may be lengthened by patent term adjustment, which compensates a patentee for administrative delays by the U.S. Patent and Trademark Office in granting a patent, or may be shortened if a patent is terminally disclaimed over an earlier expiring patent. Our patents expire at various times over the next 20 years, with patent protection for some expiring from 2024 through 2034. We do not expect such expirations to materially affect our business as the patents set to expire during this time cover intellectual property that is used in combination with other proprietary technologies, which technologies are therefore are covered by patents and patent applications with expiration dates beyond 2032. For these reasons, among others, we believe that no single patent expiration would have a material adverse effect on our business as a whole.
 The term of a patent that covers an FDA-approved drug may also be eligible for patent term extension, which permits patent term restoration of a U.S. patent as compensation for the patent term lost during the FDA regulatory review process. The Hatch-Waxman Act permits a patent term extension of up to five years beyond the expiration of the patent. The length of the patent term extension is related to the length of time the drug is under regulatory review. A patent term extension cannot extend the remaining term of a patent beyond a total of 14 years from the date of product approval and only one patent applicable to an approved drug may be extended. Moreover, a patent can only be extended once, and thus, if a single patent is applicable to multiple products, it can only be extended based on one product. Similar provisions are available in Europe and other foreign jurisdictions to extend the term of a patent that covers an approved drug. When possible, depending upon the length of clinical trials and other factors involved in the filing of a BLA, we expect to apply for patent term extensions for patents covering our approved products or methods of using the same.

 We seek to protect our proprietary technology and processes, in part, by entering into confidentiality agreements with our employees, consultants, scientific advisors and third parties. We also seek to preserve the integrity and confidentiality of our data by maintaining physical security of our premises and physical and electronic security of our information technology systems. While we have confidence in these individuals, organizations and systems, agreements or security measures may be breached, and we may not have adequate remedies for any breach. To the extent that our consultants or collaborators use intellectual property owned by others in their work for us, disputes may arise as to the rights in related or resulting know-how and inventions.
 Government Regulation
 In the United States, biological products, including cell and gene therapy products, are subject to regulation under the Federal Food, Drug, and Cosmetic Act, or FD&C Act, and the Public Health Service Act, or PHS Act, and other federal, state, local and foreign statutes and regulations. Both the FD&C Act and the PHS Act and their corresponding regulations govern, among other things, the testing, research, development, manufacturing, quality control, safety, efficacy, labeling, packaging, storage, record keeping, distribution, approval, reporting, import, export, post-approval monitoring and reporting, and advertising and other promotional practices involving biological products. FDA authorization must be obtained before clinical testing of biological products, and each clinical study protocol for a cell and gene therapy product is reviewed by the FDA. FDA approval also must be obtained before marketing of biological products. The process of obtaining regulatory approvals and the subsequent compliance with appropriate federal, state, local and foreign statutes and regulations require the expenditure of substantial time and financial resources and we may not be able to obtain the required regulatory approvals.
 Within the FDA, the Center for Biologics Evaluation and Research, or CBER, regulates cell and gene therapy products. CBER works closely with the NIH. The FDA and the NIH have published guidance documents with respect to the development and submission of gene therapy protocols. The FDA also has published guidance documents related to, among other things, gene therapy products in general, their preclinical assessment, observing subjects involved in gene therapy studies for delayed adverse events, potency testing, and chemistry, manufacturing and control information in gene therapy INDs.
 Ethical, social and legal concerns about gene therapy, genetic testing and genetic research could result in additional regulations restricting or prohibiting the processes we may use. Federal and state agencies, congressional committees and foreign governments have expressed interest in further regulating biotechnology. More restrictive regulations or claims that our products are unsafe or pose a hazard could prevent us from successfully commercializing our product or any future products. New government requirements may be established that could delay or prevent regulatory approval of our product candidates under development. It is impossible to predict whether legislative changes will be enacted, regulations, policies or guidance changed, or interpretations by agencies or courts changed, or what the impact of such changes, if any, may be.
 United States Biological Products Development Process
 The process required by the FDA before a biological product may be marketed in the United States generally involves the following:
 • completion of nonclinical laboratory tests and animal studies according to good laboratory practices, or GLPs, and applicable requirements for the humane use of laboratory animals or other applicable regulations;
 • submission to the FDA of an application for an IND, which must become effective before human clinical studies may begin and must be updated annually and when certain changes are made;
 • approval by an Institutional Review Board, or IRB, or independent ethics committee at each clinical trial site before each trial may be initiated;
 • performance of adequate and well-controlled human clinical studies according to the FDA's regulations commonly referred to as good clinical practices, or GCPs, and any additional requirements for the

 protection of human research subjects and their health information, to establish the safety and efficacy of the proposed biological product for its intended use;
 • submission to the FDA of a Biologics License Application, or BLA, for marketing approval that includes substantive evidence of safety, purity, and potency from results of nonclinical testing and clinical studies, and payment of a user fee, unless waived;
 • satisfactory completion of an FDA inspection of the manufacturing facility or facilities where the biological product is produced to assess compliance with good manufacturing practices, or GMPs, to assure that the facilities, methods and controls are adequate to preserve the biological product's identity, strength, quality and purity and, if applicable, the FDA's current good tissue practices, or GTPs, for the use of human cellular and tissue products;
 • potential FDA audit of the nonclinical and clinical study sites that generated the data in support of the BLA; and
 • FDA review and approval, or licensure, of the BLA.
 Before testing any biological product candidate in humans, the product candidate enters the preclinical testing stage. Preclinical tests, also referred to as nonclinical studies, include laboratory evaluations of product chemistry, toxicity and formulation, as well as animal studies to assess the potential safety and activity of the product candidate. The conduct of the preclinical tests must comply with federal regulations and requirements including GLPs.
 The clinical study sponsor must submit the results of the preclinical tests, together with manufacturing information, analytical data, any available clinical data or literature and a proposed clinical protocol, to the FDA as part of the IND. Some preclinical testing may continue even after the IND is submitted. The IND automatically becomes effective 30 days after receipt by the FDA, unless the FDA places the clinical study on a clinical hold within that 30-day time period. In such a case, the IND sponsor and the FDA must resolve any outstanding concerns before the clinical study can begin. A clinical hold may either be a full clinical hold or a partial clinical hold that would limit a trial, for example, to certain doses or for a certain length of time or to a certain number of subjects. The FDA may also impose clinical holds on a biological product candidate at any time before or during clinical studies due to safety concerns or non-compliance. If the FDA imposes a clinical hold, studies may not commence or recommence without FDA authorization and then only under terms authorized by the FDA. Accordingly, we cannot be sure that submission of an IND will result in the FDA allowing clinical studies to begin, or that, once begun, issues will not arise that suspend or terminate such studies.
 In addition to the submission of an IND to the FDA before initiation of a clinical trial in the United States, certain clinical studies of cells containing recombinant or synthetic nucleic acid molecules, including human gene transfer studies, are subject to oversight of institutional biosafety committees, or IBCs, as set forth in the NIH Guidelines for Research Involving Recombinant or Synthetic Nucleic Acid Molecules, or the NIH Guidelines. Specifically, under the NIH Guidelines, supervision of human gene transfer trials includes evaluation and assessment by an IBC, a local institutional committee that reviews and oversees research utilizing recombinant or synthetic nucleic acid molecules conducted at that institution. The IBC assesses the safety of the research and identifies any potential risk to public health or the environment, and such review may result in some delay before initiation of a clinical trial. Compliance with the NIH Guidelines is mandatory for investigators at institutions receiving NIH funds for research involving recombinant DNA; however, many companies and other institutions not otherwise subject to the NIH Guidelines voluntarily follow them. Such trials remain subject to FDA and other clinical trial regulations, and only after FDA, IBC, and other relevant approvals are in place can these protocols proceed.
 Clinical studies involve the administration of the biological product candidate to healthy volunteers or patients under the supervision of qualified investigators, generally physicians not employed by or under the study sponsor's control. Clinical studies are conducted under protocols detailing, among other things, the objectives of the clinical study, dosing procedures, subject selection and exclusion criteria, and the parameters to be used to monitor subject safety and effectiveness, including stopping rules that assure a clinical study will be stopped if certain adverse events should occur. Each protocol and any amendments to the protocol must be submitted to the FDA as part of the IND.

 Clinical studies must be conducted and monitored in accordance with the FDA's regulations comprising the GCP requirements, including the requirement that all research subjects provide informed consent. Further, each clinical study must be reviewed and approved by an IRB at or servicing each institution at which the clinical study will be conducted. An IRB is charged with protecting the welfare and rights of study participants and considers such items as whether the risks to individuals participating in the clinical studies are minimized and are reasonable in relation to anticipated benefits. The IRB also approves the form and content of the informed consent that must be signed by each clinical study subject or his or her legal representative and must monitor the clinical study until completed.
 Human clinical studies are typically conducted in three sequential phases that may overlap or be combined:
 • Phase 1. The biological product is initially introduced into healthy human subjects and tested for safety. In the case of some products for severe or life-threatening diseases, especially when the product may be too inherently toxic to ethically administer to healthy volunteers, the initial human testing is often conducted in patients who have the disease or condition the product candidate is intended to treat. These studies are typically designed to test the safety, dosage tolerance, absorption, metabolism and distribution of the investigational product in humans, evaluate the side effects associated with increasing doses, and, if possible, to gain early evidence of effectiveness.
 • Phase 2. The biological product is evaluated in a limited patient population with a specified disease or condition to identify possible adverse effects and safety risks, to preliminarily evaluate the efficacy of the product for specific targeted diseases and to determine dosage tolerance, optimal dosage and dosing schedule.
 • Phase 3. Clinical studies are undertaken to further evaluate dosage, clinical efficacy, potency, and safety in an expanded patient population at geographically dispersed clinical study sites. These clinical studies are intended to establish the overall risk/benefit ratio of the product and provide an adequate basis for product approval and labeling. Generally, two adequate and well-controlled Phase 3 clinical trials are required by the FDA for approval of a BLA.
 Post-approval clinical studies, sometimes referred to as Phase 4 clinical studies, may be conducted after initial marketing approval. These clinical studies are used to gain additional experience from the treatment of patients in the intended therapeutic indication, particularly for long-term safety follow-up. In some cases, the FDA may mandate the performance of Phase 4 clinical trials as a condition of approval of a BLA. The FDA generally recommends that sponsors observe subjects for potential gene therapy-related delayed adverse events for a 15-year period, including a minimum of five years of annual examinations followed by ten years of annual queries, either in person or by questionnaire, of study subjects.
 During all phases of clinical development, regulatory agencies require extensive monitoring and auditing of all clinical activities, clinical data, and clinical study investigators. Annual progress reports detailing the results of the clinical studies must be submitted to the FDA. Written IND safety reports must be promptly submitted to the FDA, the NIH, as applicable, and the investigators for serious and unexpected adverse events, any findings from other studies, tests in laboratory animals or in vitro testing that suggest a significant risk for human subjects, or any clinically important increase in the rate of a serious suspected adverse reaction over that listed in the protocol or investigator brochure. The sponsor must submit an IND safety report within 15 calendar days after the sponsor determines that the information qualifies for reporting. The sponsor also must notify the FDA of any unexpected fatal or life-threatening suspected adverse reaction within seven calendar days after the sponsor's initial receipt of the information. Phase 1, Phase 2 and Phase 3 clinical studies may not be completed successfully within any specified period, if at all. The FDA or the sponsor or its data safety monitoring board may suspend a clinical study at any time on various grounds, including a finding that the research subjects or patients are being exposed to an unacceptable health risk. Similarly, an IRB can suspend or terminate approval of a clinical study at its institution if the clinical study is not being conducted in accordance with the IRB's requirements or if the biological product has been associated with unexpected serious harm to patients.
 Human cell and gene therapy products are a new category of therapeutics. Because this is a relatively new and expanding area of novel therapeutic interventions, there can be no assurance as to the length of the study period, the

 number of patients the FDA will require to be enrolled in the studies in order to establish the safety, efficacy, purity and potency of human cell and gene therapy products, or that the data generated in these studies will be acceptable to the FDA to support marketing approval.
 Concurrent with clinical studies, companies usually complete additional animal studies and must also develop additional information about the physical characteristics of the biological product as well as finalize a process for manufacturing the product in commercial quantities in accordance with GMP requirements. To help reduce the risk of the introduction of adventitious agents with use of biological products, the PHS Act emphasizes the importance of manufacturing control for products whose attributes cannot be precisely defined. The manufacturing process must be capable of consistently producing quality batches of the product candidate and, among other things, the sponsor must develop methods for testing the identity, strength, quality, potency and purity of the final biological product. Additionally, appropriate packaging must be selected and tested and stability studies must be conducted to demonstrate that the biological product candidate does not undergo unacceptable deterioration over its shelf life and to identify appropriate storage conditions for the product candidate.
 United States Review and Approval Processes
 After the completion of clinical studies of a biological product, FDA approval of a BLA must be obtained before commercial marketing of the biological product. The BLA must include results of product development, laboratory and animal studies, human studies, information on the manufacture and composition of the product, proposed labeling and other relevant information. In addition, under the Pediatric Research Equity Act, or PREA, as amended, a BLA or supplement to a BLA must contain data to assess the safety and effectiveness of the biological product for the claimed indications in all relevant pediatric subpopulations and to support dosing and administration for each pediatric subpopulation for which the product is safe and effective. The FDA may grant deferrals for submission of data or full or partial waivers. Unless otherwise required by regulation, PREA does not apply to any biological product for an indication for which orphan designation has been granted. The testing and approval processes require substantial time and effort and there can be no assurance that the FDA will accept the BLA for filing and, even if filed, that any approval will be granted on a timely basis, if at all.
 Within 60 days following submission of the application, the FDA reviews a BLA submitted to determine if it is substantially complete before the agency accepts it for filing. The FDA may refuse to file any BLA that it deems incomplete or not properly reviewable at the time of submission and may request additional information. In this event, the BLA must be resubmitted with the additional information. The resubmitted application also is subject to review before the FDA accepts it for filing. Once the submission is accepted for filing, the FDA begins an in-depth substantive review of the BLA. The FDA reviews the BLA to determine, among other things, whether the proposed product is safe and potent, or effective, for its intended use, and has an acceptable purity profile, and whether the product is being manufactured in accordance with GMP to assure and preserve the product's identity, safety, strength, quality, potency and purity. Each BLA must be accompanied by a user fee, and the sponsor of an approved BLA is also subject to an annual program fee. The FDA may refer applications for novel biological products or biological products that present difficult questions of safety or efficacy to an advisory committee, typically a panel that includes clinicians and other experts, for review, evaluation and a recommendation as to whether the application should be approved and under what conditions. The FDA is not bound by the recommendations of an advisory committee, but it considers such recommendations carefully when making decisions. During the biological product approval process, the FDA also will determine whether a Risk Evaluation and Mitigation Strategy, or REMS, is necessary to assure the safe use of the biological product. If the FDA concludes a REMS is needed, the sponsor of the BLA must submit a proposed REMS; the FDA will not approve the BLA without a REMS, if required.
 Before approving a BLA, the FDA will inspect the facilities at which the product is manufactured. The FDA will not approve the product unless it determines that the manufacturing processes and facilities are in compliance with GMP requirements and adequate to assure consistent production of the product within required specifications. For a cell or gene therapy product, the FDA also will not approve the product if the manufacturer is not in compliance with the GTPs. These are FDA regulations that govern the methods used in, and the facilities and controls used for, the manufacture of human cells, tissues, and cellular and tissue based products, or HCT/Ps, which are human cells or tissue intended for implantation, transplant, infusion, or transfer into a human recipient. The primary intent of the GTP requirements is to ensure that cell and tissue based products are manufactured in a manner

 designed to prevent the introduction, transmission and spread of communicable disease. FDA regulations also require tissue establishments to register and list their HCT/Ps with the FDA and, when applicable, to evaluate donors through screening and testing. Additionally, before approving a BLA, the FDA will typically inspect one or more clinical sites to assure that the clinical studies were conducted in compliance with IND study requirements and GCP requirements. To assure GMP, GTP and GCP compliance, an applicant must incur significant expenditure of time, money and effort in the areas of training, record keeping, production, and quality control.
 Notwithstanding the submission of relevant data and information, the FDA may ultimately decide that the BLA does not satisfy its regulatory criteria for approval and deny approval. Data obtained from clinical studies are not always conclusive and the FDA may interpret data differently than we interpret the same data. If the agency decides not to approve the BLA in its present form, the FDA will issue a complete response letter that usually describes all of the specific deficiencies in the BLA identified by the FDA. The deficiencies identified may be minor, for example, requiring labeling changes, or major, for example, requiring additional clinical studies. Additionally, the complete response letter may include recommended actions that the applicant might take to place the application in a condition for approval. If a complete response letter is issued, the applicant may either resubmit the BLA, addressing all of the deficiencies identified in the letter, withdraw the application, or request a hearing.
 If a product receives regulatory approval, the approval may be significantly limited to specific diseases and dosages or the indications for use may otherwise be limited, which could restrict the commercial value of the product. Further, the FDA may require that certain contraindications, warnings or precautions be included in the product labeling. The FDA may impose restrictions and conditions on product distribution, prescribing, or dispensing in the form of a risk management plan, or otherwise limit the scope of any approval. In addition, the FDA may require Phase 4 clinical studies, designed to further assess a biological product's safety and effectiveness, and testing and surveillance programs to monitor the safety of approved products that have been commercialized.
 One of the performance goals agreed to by the FDA under the Prescription Drug User Fee Act, or PDUFA, is to review 90% of standard BLAs within 10 months of the 60-day filing date and 90% of priority BLAs within six months of the 60-day filing date, whereupon a review decision is to be made. The FDA does not always meet its PDUFA goal dates for standard and priority BLAs and its review goals are subject to change from time to time. The review process and the PDUFA goal date may be extended by three months if the FDA requests or the BLA sponsor otherwise provides certain additional information or clarification regarding information already provided in the submission.
 Orphan Drug Designation and Exclusivity
 Under the Orphan Drug Act of 1983 or the Orphan Drug Act, the FDA may grant orphan designation to a drug or biological product intended to treat a rare disease or condition, which is generally a disease or condition that affects fewer than 200,000 individuals in the United States, or more than 200,000 individuals in the United States and for which there is no reasonable expectation that the cost of developing and making a drug or biological product available in the United States for this type of disease or condition will be recovered from sales of the product. Orphan designation must be requested before submitting a new drug application, or NDA, or BLA. After the FDA grants orphan designation, the identity of the therapeutic agent and its potential orphan use are disclosed publicly by the FDA. Orphan designation does not convey any advantage in or shorten the duration of the regulatory review and approval process.
 If a product that has orphan designation subsequently receives the first FDA approval for the disease or condition for which it has such designation, the product is entitled to orphan product exclusivity, which means that the FDA may not approve any other applications to market the same drug or biological product for the same indication for seven years, except in limited circumstances, such as a showing of clinical superiority to the product with orphan exclusivity. Competitors, however, may receive approval of different products for the indication for which the orphan product has exclusivity or obtain approval for the same product but for a different indication for which the orphan product has exclusivity. Orphan product exclusivity also could block the approval of one of our future products for seven years if a competitor obtains approval of the same biological product as defined by the FDA or if our product candidate is determined to be contained within the competitor's product for the same indication or disease. If a drug or biological product designated as an orphan product receives marketing approval

 for an indication broader than what is designated, it may not be entitled to orphan product exclusivity. Orphan designation may also be lost if the FDA later determines that the request for designation was materially defective or if the manufacturer is unable to assure sufficient quantities of the product to meet the needs of the patient with the rare disease or condition. Orphan product designation in the EU has similar, but not identical, benefits.
 Expedited Development and Review Programs
 The FDA has established several programs intended to facilitate and expedite development and review of new drugs and biologics to address unmet medical needs in the treatment of serious or life-threatening diseases or conditions. These programs include fast track designation, breakthrough therapy designation, priority review and accelerated approval.
 New drugs and biological products are eligible for fast track designation if they are intended to treat a serious or life-threatening condition and demonstrate the potential to address unmet medical needs for the condition. Fast track designation applies to the combination of the product and the specific indication for which it is being studied. The sponsor of a new drug or biologic may request the FDA to designate the drug or biologic as a fast track product at any time during the clinical development of the product. The FDA may consider for review sections of the marketing application on a rolling basis before the complete application is submitted, if the sponsor provides a schedule for the submission of the sections of the application, the FDA agrees to accept sections of the application and determines that the schedule is acceptable, and the sponsor pays any required user fees upon submission of the first section of the application. A product may be eligible for other types of FDA programs intended to expedite development and review, such as priority review, accelerated approval, and breakthrough therapy designation. Under the breakthrough therapy program, products intended to treat a serious or life-threatening disease or condition may be eligible for the benefits of the fast track program when preliminary clinical evidence demonstrates that such product may have substantial improvement on one or more clinically significant endpoints over existing therapies. Breakthrough Therapy designation includes all of the benefits of Fast Track designation in addition to intensive guidance on a development program beginning as early as Phase 1. Additionally, FDA will seek to ensure the sponsor of a breakthrough therapy product receives timely advice and interactive communications to help the sponsor design and conduct a development program as efficiently as possible. A product may also be eligible for priority review if it has the potential to provide safe and effective therapy where no satisfactory alternative therapy exists or a significant improvement in the treatment, diagnosis or prevention of a disease compared to marketed products. The FDA will attempt to direct additional resources to the evaluation of an application for a new drug or biological product designated for priority review in an effort to facilitate the review. Additionally, a product may be eligible for accelerated approval. Drug or biological products studied for their safety and effectiveness in treating serious or life-threatening illnesses and that provide meaningful therapeutic benefit over existing treatments may receive accelerated approval, which means that they may be approved on the basis of adequate and well-controlled clinical studies establishing that the product has an effect on a surrogate endpoint that is reasonably likely to predict a clinical benefit, or on the basis of an effect on a clinical endpoint other than survival or irreversible morbidity. As a condition of approval, the FDA may require that a sponsor of a drug or biological product receiving accelerated approval perform adequate and well-controlled post-marketing clinical studies. Under the Food and Drug Omnibus Reform Act of 2022, or FDORA, the FDA is now permitted to require, as appropriate, that such trials be underway prior to approval or within a specific time period after the date of approval for a product granted accelerated approval. Sponsors are also required to send updates to the FDA every 180 days on the status of such studies, including progress toward enrollment targets, and the FDA must promptly post this information publicly. Under FDORA, the FDA has increased authority for expedited procedures to withdraw approval of a drug or indication approved under accelerated approval if, for example, the sponsor fails to conduct such studies in a timely manner and send the necessary updates to the FDA, or if a confirmatory trial fails to verify the predicted clinical benefit of the product. In addition, for products being considered for accelerated approval, the FDA currently requires, unless otherwise informed by the agency, that all advertising and promotional materials intended for dissemination or publication within 120 days of marketing approval be submitted to the agency for review during the pre-approval review period, which could adversely impact the timing of the commercial launch of the product. Fast track designation, breakthrough therapy designation, priority review and accelerated approval do not change the standards for approval but may expedite the development or approval process.

 Regenerative Medicine Advanced Therapies Designation
 As part of the 21st Century Cures Act, Congress amended the FD&C Act to facilitate an efficient development program for, and expedite review of regenerative medicine advanced therapies, which include cell and gene therapies, therapeutic tissue engineering products, human cell and tissue products, and combination products using any such therapies or products. Regenerative medicine advanced therapies do not include those human cells, tissues, and cellular and tissue based products regulated solely under section 361 of the PHS Act and 21 CFR Part 1271. This program is intended to facilitate efficient development and expedite review of regenerative medicine therapies, which are intended to treat, modify, reverse, or cure a serious or life-threatening disease or condition and qualify for RMAT designation. A drug sponsor may request that FDA designate a drug as an RMAT concurrently with or at any time after submission of an IND. FDA has 60 calendar days to determine whether the drug meets the criteria, including whether there is preliminary clinical evidence indicating that the drug has the potential to address unmet medical needs for a serious or life-threatening disease or condition. A BLA for a regenerative medicine therapy that has received RMAT designation may be eligible for priority review or accelerated approval through use of surrogate or intermediate endpoints reasonably likely to predict long-term clinical benefit, or reliance upon data obtained from a meaningful number of sites. Benefits of RMAT designation also include early interactions with FDA to discuss any potential surrogate or intermediate endpoint to be used to support accelerated approval. A regenerative medicine therapy with RMAT designation that is granted accelerated approval and is subject to post-approval requirements may fulfill such requirements through the submission of clinical evidence from clinical studies, patient registries, or other sources of real world evidence, such as electronic health records; the collection of larger confirmatory data sets; or post-approval monitoring of all patients treated with such therapy prior to its approval.
 Post-Approval Requirements
 Maintaining compliance with applicable federal, state, and local statutes and regulations requires the expenditure of substantial time and financial resources. Rigorous and extensive FDA regulation of biological products continues after approval, particularly with respect to GMP. We will rely, and expect to continue to rely, on third parties for the production of clinical and commercial quantities of any future products that we may commercialize. Manufacturers of our products are required to comply with applicable requirements in the GMP regulations, including quality control and quality assurance and maintenance of records and documentation. For certain commercial prescription drug and biologic products, manufacturers and other parties involved in the supply chain must also meet chain of distribution requirements and build electronic, interoperable systems for product tracking and tracing and for notifying the FDA of counterfeit, diverted, stolen and intentionally adulterated products or other products that are otherwise unfit for distribution in the United States. Other post-approval requirements applicable to biological products include reporting of GMP deviations that may affect the identity, potency, purity and overall safety of a distributed product, record-keeping requirements, reporting of adverse effects, reporting updated safety and efficacy information, and complying with electronic record and signature requirements. After a BLA is approved, the product also may be subject to official lot release. As part of the manufacturing process, the manufacturer is required to perform certain tests on each lot of the product before it is released for distribution. If the product is subject to official release by the FDA, the manufacturer submits samples of each lot of product to the FDA together with a release protocol showing a summary of the history of manufacture of the lot and the results of all of the manufacturer's tests performed on the lot. The FDA also may perform certain confirmatory tests on lots of some products, such as viral vaccines, before releasing the lots for distribution by the manufacturer. In addition, the FDA conducts laboratory research related to the regulatory standards on the safety, purity, potency, and effectiveness of biological products.
 Biological product manufacturers and other entities involved in the manufacture and distribution of approved biological products are required to register their establishments with the FDA and certain state agencies, and are subject to periodic unannounced inspections by the FDA and certain state agencies for compliance with GMPs and other laws. Accordingly, manufacturers must continue to expend time, money, and effort in the area of production and quality control to maintain GMP compliance. Discovery of problems with a product after approval may result in restrictions on a product, manufacturer, or holder of an approved BLA, including withdrawal of the product from the market. In addition, changes to the manufacturing process or facility generally require prior FDA approval before being implemented and other types of changes to the approved product, such as adding new indications and additional labeling claims, are also subject to further FDA review and approval. In addition, companies that

 manufacture or distribute drug or biological products or that hold approved BLAs must comply with other regulatory requirements, including submitting annual reports, reporting information about adverse drug experiences, and maintaining certain records. Newly discovered or developed safety or effectiveness data may require changes to a drug's approved labeling, including the addition of new warnings and contraindications, and also may require the implementation of other risk management measures, including a REMS or the conduct of post-marketing studies to assess a newly-discovered safety issue.
 We also must comply with the FDA's and other jurisdictions' advertising and promotion requirements, such as those related to direct-to-consumer advertising and advertising to healthcare professionals, the prohibition on promoting products for uses or in patient populations that are not described in the product's approved labeling (known as "off-label use"), industry-sponsored scientific and educational activities, and promotional activities involving the internet. Discovery of previously unknown problems or the failure to comply with the applicable regulatory requirements may result in restrictions on the marketing of a product or withdrawal of the product from the market as well as possible civil or criminal sanctions. Failure to comply with the applicable United States requirements at any time during the product development process, approval process or after approval, may subject an applicant or manufacturer to administrative or judicial civil or criminal sanctions and adverse publicity. Consequences could include refusal to approve pending applications, withdrawal of an approval, clinical hold, warning or untitled letters, product recalls, product seizures, total or partial suspension of production or distribution, injunctions, fines, refusals of government contracts, mandated corrective advertising or communications with healthcare professionals, debarment, restitution, disgorgement of profits, or civil or criminal penalties. Any agency or judicial enforcement action could have a material adverse effect on us. Although physicians may prescribe approved products for off-label use, manufacturers may not market or promote such uses. The FDA and other agencies actively enforce the laws and regulations prohibiting the promotion of off-label uses, and a company that is found to have improperly promoted off-label uses may be subject to significant liability. Failure to comply with these requirements can result in, among other things, adverse publicity, warning letters, corrective advertising and potential civil and criminal penalties, including liabilities under the False Claims Act where products carry reimbursement under federal health care programs. Promotional materials for approved biologics must be submitted to the FDA in conjunction with their first use or first publication.
 United States Patent Term Restoration and Marketing Exclusivity
 Depending upon the timing, duration and specifics of the FDA approval of the use of our product candidates, some of our United States patents may be eligible for limited patent term extension under the Drug Price Competition and Patent Term Restoration Act of 1984, commonly referred to as the Hatch-Waxman Amendments. The Hatch-Waxman Amendments permit a patent restoration term of up to five years as compensation for patent term lost during product development and the FDA regulatory review process. However, patent term restoration cannot extend the remaining term of a patent beyond a total of 14 years from the product's approval date and only those claims covering such approved biological product, a method for using it, or a method for manufacturing it may be extended. The patent term restoration period is generally one-half the time between the effective date of an IND and the submission date of a BLA plus the time between the submission date of a BLA and the approval of that application. Only one patent applicable to an approved biological product is eligible for the extension and the application for the extension must be submitted prior to the expiration of the patent. The United States PTO, in consultation with the FDA, reviews and approves the application for any patent term extension or restoration. In the future, we may intend to apply for restoration of patent term for one of our currently owned or licensed patents to add patent life beyond its current expiration date, depending on the expected length of the clinical studies and other factors involved in the filing of the relevant BLA.
 A biological product can obtain pediatric market exclusivity in the United States. Pediatric exclusivity, if granted, adds six months to existing exclusivity periods for all formulations, dosage forms, and indications of the active moiety. This six-month exclusivity, which runs from the end of other exclusivity protection, may be granted based on the voluntary completion of a pediatric study in accordance with an FDA-issued "Written Request" for such a study, provided that at the time pediatric exclusivity is granted there is not less than nine months of term remaining.

 The Patient Protection and Affordable Care Act, or Affordable Care Act, signed into law on March 23, 2010, includes a subtitle called the Biologics Price Competition and Innovation Act of 2009, or the BPCIA, which created an abbreviated approval pathway for biological products shown to be similar to, or interchangeable with, an FDA-licensed reference biological product. The BPCIA attempts to minimize duplicative testing. Biosimilarity, which requires that there be no clinically meaningful differences between the biological product and the reference product in terms of safety, purity, and potency, can be shown through analytical studies, animal studies, and a clinical study or studies. Interchangeability requires that a product is biosimilar to the reference product and the product must demonstrate that it can be expected to produce the same clinical results as the reference product and, for products administered multiple times, the biologic and the reference biologic may be switched after one has been previously administered without increasing safety risks or risks of diminished efficacy relative to exclusive use of the reference biologic.
 Under the BPCIA, a reference biologic is granted 12 years of exclusivity from the time of first licensure of the reference product, and an application for a biosimilar product may not be submitted to the FDA until four years following the date that the reference product was first licensed by the FDA. The first biologic product submitted under the abbreviated approval pathway that is determined to be interchangeable with the reference product has exclusivity against other biologics submitting under the abbreviated approval pathway for the lesser of (i) one year after the first commercial marketing, (ii) 18 months after approval if there is no legal challenge, (iii) 18 months after the resolution in the applicant's favor of a lawsuit challenging the biologics' patents if an application has been submitted, or (iv) 42 months after the application has been approved if a lawsuit is ongoing within the 42-month period. The FDA may approve multiple "first" interchangeable products so long as they are all approved on the same first day of marketing, and the exclusivity period may be shared among multiple first interchangeable products.
 Healthcare and Privacy Laws
 In addition to restrictions on marketing of pharmaceutical products, several other types of state/federal laws and trade association membership codes of conduct have been applied to restrict certain marketing practices in the pharmaceutical industry in recent years. These laws include Anti-Kickback and false claims statutes. The United States federal healthcare program Anti-Kickback statute prohibits, among other things, knowingly and willfully offering, paying, soliciting or receiving remuneration, directly or indirectly, in cash or in kind, to induce or in return for purchasing, leasing, ordering or arranging for or recommending the purchase, lease or order of any healthcare item or service reimbursable, in whole or in part, under Medicare, Medicaid or other federally financed healthcare programs. This statute has been interpreted to apply to arrangements between pharmaceutical manufacturers on one hand and prescribers, purchasers, and formulary managers on the other. A person or entity need not have actual knowledge of the federal Anti-Kickback Statute or specific intent to violate it in order to have committed a violation. Violations are subject to civil and criminal fines and penalties for each violation, plus up to three times the remuneration involved, imprisonment, and exclusion from government healthcare programs. Although there are a number of statutory exemptions and regulatory safe harbors protecting certain common activities from prosecution, the exemptions and safe harbors are drawn narrowly and practices that involve remuneration to those who prescribe, purchase, or recommend pharmaceutical and biological products, including certain discounts, or engaging healthcare professionals or patients as speakers or consultants, may be subject to scrutiny if they do not fit squarely within the exemption or safe harbor. Our practices may not in all cases meet all of the criteria for safe harbor protection from anti-kickback liability. Moreover, there are no safe harbors for many common practices, such as educational and research grants or patient assistance programs.
 The United States federal civil False Claims Act prohibits, among other things, any person from knowingly presenting, or causing to be presented, a false or fraudulent claim for payment of government funds, or knowingly making, using, or causing to be made or used, a false record or statement material to an obligation to pay money to the government or knowingly concealing or knowingly and improperly avoiding, decreasing, or concealing an obligation to pay money to the federal government. Manufacturers can be held liable under the False Claims Act even when they do not submit claims directly to government payers if they are deemed to "cause" the submission of false or fraudulent claims. The False Claims Act also permits a private individual acting as a "whistleblower" to bring actions on behalf of the federal government alleging violations of the False Claims Act and to share in any monetary recovery. In recent years, several pharmaceutical and other healthcare companies have faced enforcement actions under the federal False Claims Act for, among other things, allegedly submitting false or misleading pricing

 information to government health care programs and providing free product to customers with the expectation that the customers would bill federal programs for the product. Other companies have faced enforcement actions for causing false claims to be submitted because of the company's marketing the product for unapproved, and thus non-reimbursable, uses. Federal enforcement agencies also have showed increased interest in pharmaceutical companies' product and patient assistance programs, including reimbursement and co-pay support services, and a number of investigations into these programs have resulted in significant civil and criminal settlements. In addition, the Affordable Care Act amended federal law to provide that the government may assert that a claim including items or services resulting from a violation of the federal Anti-Kickback statute constitutes a false or fraudulent claim for purposes of the federal civil False Claims Act. Criminal prosecution is possible for making or presenting a false or fictitious or fraudulent claim to the federal government.
 The Health Insurance Portability and Accountability Act of 1996, or HIPAA, also created several new federal crimes, including healthcare fraud and false statements relating to healthcare matters. The healthcare fraud statute prohibits knowingly and willfully executing a scheme to defraud any healthcare benefit program, including private third-party payers. The false statements statute prohibits knowingly and willfully falsifying, concealing or covering up a material fact or making any materially false, fictitious or fraudulent statement in connection with the delivery of or payment for healthcare benefits, items or services. Similar to the federal Anti-Kickback Statute, a person or entity does not need to have actual knowledge of the statute or specific intent to violate it in order to have committed a violation.
 The United States Federal Physician Payment Sunshine Act, being implemented as the Open Payments Program, requires certain manufacturers of drugs, devices, biologics and medical supplies to engage in extensive tracking of payments and other transfers of value to physicians, certain other licensed health care practitioners and teaching hospitals, including physician ownership and investment interests, and public reporting of such data. Pharmaceutical and biological manufacturers with products for which payment is available under Medicare, Medicaid or the State Children's Health Insurance Program are required to track such payments, and must submit a report on or before the 90th day of each calendar year disclosing reportable payments made in the previous calendar year. Additionally, federal government price reporting laws, which require us to calculate and report complex pricing metrics in an accurate and timely manner to government programs and consumer protection and unfair competition laws, which broadly regulate marketplace activities and activities that potentially harm consumers, may apply to us. A number of other countries, states and municipalities have also implemented additional payment tracking and reporting requirements, which if not done correctly may result in additional penalties.
 In addition, the United States Foreign Corrupt Practices Act, or the FCPA, prohibits corporations and individuals from engaging in certain activities to obtain or retain business or to influence a person working in an official capacity. It is illegal to pay, offer to pay or authorize the payment of anything of value to any official of another country, government staff member, political party or political candidate in an attempt to obtain or retain business or to otherwise influence a person working in that capacity. In many other countries, healthcare professionals who prescribe pharmaceuticals are employed by government entities, and the purchasers of pharmaceuticals are government entities. Our dealings with these prescribers and purchasers may be subject to the FCPA.
 Other countries, including a number of EU member states, have laws of similar application, including anti-bribery or anti-corruption laws such as the UK Bribery Act. The UK Bribery Act prohibits giving, offering, or promising bribes to any person, as well as requesting, agreeing to receive, or accepting bribes from any person. Under the UK Bribery Act, a company that carries on a business or part of a business in the United Kingdom may be held liable for bribes given, offered or promised to any person in any country by employees or other persons associated with the company in order to obtain or retain business or a business advantage for the company. Liability under the UK Bribery Act is strict, but a defense of having in place adequate procedures designed to prevent bribery is available.
 HIPAA, as amended by the Health Information Technology for Economic and Clinical Health Act of 2009, or HITECH and their respective implementing regulations, including the Final Omnibus Rule published in January 2013, impose requirements on certain covered healthcare providers, health plans, and healthcare clearinghouses as well as their respective business associates that perform services for them that involve the use, or disclosure of,

 individually identifiable health information, relating to the privacy, security and transmission of individually identifiable health information. HITECH also created new tiers of civil monetary penalties, amended HIPAA to make civil and criminal penalties directly applicable to business associates, and gave state attorneys general new authority to file civil actions for damages or injunctions in federal courts to enforce the federal HIPAA laws and seek attorneys' fees and costs associated with pursuing federal civil actions. In addition, there may be additional federal, state and non-U.S. laws which govern the privacy and security of health and other personal information in certain circumstances, many of which differ from each other in significant ways and may not have the same effect, thus complicating compliance efforts.
 Many US states also have statutes or regulations similar to the federal anti-kickback and false claims laws, which apply to items and services reimbursed under Medicaid and other state programs, or, in several states, apply regardless of the payer. Several states now require pharmaceutical companies to report expenses relating to the marketing and promotion of pharmaceutical products in those states and to report gifts and payments to individual health care providers in those states. Some of these states also prohibit certain marketing-related activities including the provision of gifts, meals, or other items to certain health care providers. In addition, some state laws require pharmaceutical companies to comply with the pharmaceutical industry's voluntary compliance guidelines and the relevant compliance guidance promulgated by the federal government in addition to requiring manufacturers to report information related to payments to physicians and other healthcare providers, marketing expenditures, and drug pricing information. Certain state and local laws require the registration of pharmaceutical sales representatives. State laws also govern the privacy and security of health information in some circumstances, many of which differ from each other in significant ways and often are not preempted by HIPAA, thus complicating compliance efforts. In addition, globally, many countries have enacted stringent privacy and data protection laws. In the event that we begin to conduct trials outside of the United States or otherwise process personal information in countries outside of the United States, we will have to implement a comprehensive compliance program to address these requirements.
 In the United States, to help patients afford our products, we may utilize programs to assist them, including patient assistance programs and co-pay coupon programs for eligible patients. Government enforcement agencies have shown increased interest in pharmaceutical companies' product and patient assistance programs, including reimbursement support services, and a number of investigations into these programs have resulted in significant civil and criminal settlements. In addition, at least one insurer has directed its network pharmacies to no longer accept co-pay coupons for certain specialty drugs the insurer identified. Our co-pay coupon programs could become the target of similar insurer actions. In addition, in November 2013, the CMS issued guidance to the issuers of qualified health plans sold through the Affordable Care Act's marketplaces encouraging such plans to reject patient cost-sharing support from third parties and indicating that the CMS intends to monitor the provision of such support and may take regulatory action to limit it in the future. CMS subsequently issued a rule requiring individual market qualified health plans to accept third-party premium and cost-sharing payments from certain government-related entities.
 In September 2014, the OIG of the U.S. Department of Health and Human Services, or HHS issued a Special Advisory Bulletin warning manufacturers that they may be subject to sanctions under the federal anti-kickback statute and/or civil monetary penalty laws if they do not take appropriate steps to exclude Part D beneficiaries from using co-pay coupons. Accordingly, companies exclude these Part D beneficiaries from using co-pay coupons. It is possible that changes in insurer policies regarding co-pay coupons and/or the introduction and enactment of new legislation or regulatory action could restrict or otherwise negatively affect these patient support programs, which could result in fewer patients using affected products, and therefore could have a material adverse effect on our sales, business, and financial condition.
 Third party patient assistance programs that receive financial support from companies have become the subject of enhanced government and regulatory scrutiny. The OIG has established guidelines that suggest that it is lawful for pharmaceutical manufacturers to make donations to charitable organizations who provide co-pay assistance to Medicare patients, provided that such organizations, among other things, are bona fide charities, are entirely independent of and not controlled by the manufacturer, provide aid to applicants on a first-come basis according to consistent financial criteria and do not link aid to use of a donor's product. However, donations to patient assistance programs have received some negative publicity and have been the subject of multiple government enforcement actions, related to allegations regarding their use to promote branded pharmaceutical products over other less costly

 alternatives. Specifically, in recent years, there have been multiple settlements resulting out of government claims challenging the legality of their patient assistance programs under a variety of federal and state laws.
 Because of the breadth of these various healthcare and privacy laws, it is possible that some of our business activities could be subject to challenge under one or more of such laws. Such a challenge could have material adverse effects on our business, financial condition and results of operations. In the event governmental authorities conclude that our business practices do not comply with current or future statutes, regulations or case law involving applicable fraud and abuse or other healthcare and privacy laws and regulations, they may impose sanctions under these laws, which are potentially significant and may include civil monetary penalties, damages, exclusion of an entity or individual from participation in government health care programs, criminal fines and imprisonment, as well as the potential curtailment or restructuring of our operations. Even if we are not determined to have violated these laws, government investigations into these issues typically require the expenditure of significant resources and generate negative publicity, which could harm our financial condition and divert the attention of our management from operating our business.
 Government Regulation Outside of the United States
 In addition to regulations in the United States, we will be subject to a variety of regulations in other jurisdictions governing, among other things, clinical studies and any commercial sales and distribution of our products. Because biologically sourced raw materials are subject to unique contamination risks, their use may be restricted in some countries.
 Whether or not we obtain FDA approval for a product, we must obtain the requisite approvals from regulatory authorities in foreign countries prior to the commencement of clinical studies or marketing of the product in those countries. Certain countries outside of the United States have a similar process that requires the submission of a clinical trial application, or CTA, much like the IND prior to the commencement of human clinical studies. In the EU, for example, a CTA must be submitted for each clinical trial to each country's national competent authority and an independent ethics committee, much like the FDA and the IRB, respectively. Once the CTA is approved in accordance with a country's requirements, the corresponding clinical study may proceed. In April 2014, the EU adopted a new Clinical Trials Regulation (EU) No 536/2014, which entered into application to replace Clinical Trials Directive 2001/20/EC on January 31, 2022. The new Regulation, which will be directly applicable in all EU member states (meaning that no national implementing legislation in each EU member state is required), aims at simplifying and streamlining the approval of clinical trials in the EU. The main characteristics of the Regulation include: a streamlined application procedure via a single-entry point through the Clinical Trials Information System, or CTIS; a single set of documents to be prepared and submitted for the application as well as simplified reporting procedures for clinical trial sponsors; and a harmonized procedure for the assessment of applications for clinical trials, which is divided in two parts (Part I contains scientific and medicinal product documentation and Part II contains the national and patient-level documentation). Part I is assessed by a coordinated review by the competent authorities of all EU Member States in which an application for authorization of a clinical trial has been submitted (Member States concerned) of a draft report prepared by a Reference Member State. Part II is assessed separately by each Member State concerned. Strict deadlines have been established for the assessment of clinical trial applications. The role of the relevant ethics committees in the assessment procedure will continue to be governed by the national law of the concerned EU Member State. However, overall related timelines will be defined by the Clinical Trials Regulation.
 The requirements and process governing the conduct of clinical studies, product licensing, pricing and reimbursement vary from country to country. In all cases, the clinical studies are conducted in accordance with GCP and the applicable regulatory requirements and the ethical principles that have their origin in the Declaration of Helsinki.
 To obtain regulatory approval of a medicinal product in the EU, we must submit a marketing authorization application. The application used to file the BLA in the United States is similar to that required in the EU, with the exception of, among other things, region-specific document requirements. Medicinal product candidates may only be commercialized after obtaining the marketing authorization application. A centralized marketing authorization is issued by the European Commission through the centralized procedure, based on the opinion of the Committee for

 Medicinal Products for Human Use, or CHMP, of the EMA, and is valid throughout the EU, and in the additional member states of the European Economic Area, or EEA (Norway, Iceland and Liechtenstein). The centralized procedure is mandatory for certain types of products, such as biotechnology medicinal products, orphan medicinal products, advanced-therapy medicinal products (gene-therapy, somatic cell-therapy or tissue-engineered medicines), and medicinal products containing a new active substance indicated for the treatment of HIV, AIDS, cancer, neurodegenerative disorders, diabetes, auto-immune and other immune dysfunctions, and viral diseases. The centralized procedure is optional for products containing a new active substance not yet authorized in the EU, or for products that constitute a significant therapeutic, scientific or technical innovation or which are in the interest of public health in the EU.
 Under the centralized procedure the maximum timeframe for the evaluation of a marketing authorization application by the EMA is 210 days, excluding clock stops, when additional written or oral information is to be provided by the applicant in response to questions asked by the CHMP. Clock stops may extend the timeframe of evaluation of a marketing authorization application considerably beyond 210 days. Where the CHMP gives a positive opinion, it provides the opinion together with supporting documentation to the European Commission, who make the final decision to grant a marketing authorization, which is issued within 67 days of receipt of the EMA's recommendation. Accelerated assessment might be granted by the CHMP in exceptional cases, when a medicinal product is expected to be of major public health interest, particularly from the point of view of therapeutic innovation. The timeframe for the evaluation of a marketing authorization application under the accelerated assessment procedure is 150 days, excluding clock stops, but it is possible that the CHMP may revert to the standard time limit for the centralized procedure if it determines that the application is no longer appropriate to conduct an accelerated assessment.
 The EU also provides opportunities for market exclusivity. For example, in the EU, upon receiving marketing authorization, innovative medicinal products generally receive eight years of data exclusivity and an additional two years of market exclusivity. If granted, data exclusivity prevents generic or biosimilar applicants from referencing the innovator's preclinical and clinical trial data contained in the dossier of the innovative medicinal product when applying for a generic or biosimilar marketing authorization in the EU during such eight-year period starting from the date of grant of the innovative medicinal product's marketing authorization. During the additional two-year period of market exclusivity, a generic or biosimilar marketing authorization application can be submitted, and the innovator's data may be referenced, but no generic or biosimilar product can be marketed until the expiration of the market exclusivity (and the grant of the relevant generic or biosimilar marketing authorization). The overall ten-year period will be extended to a maximum of eleven years if, during the first eight years of those ten years, the marketing authorization holder obtains an authorization for one or more new therapeutic indications which, during the scientific evaluation prior to authorization, is held to bring a significant clinical benefit in comparison with existing therapies. However, there is no guarantee that a product will be considered by the EU's regulatory authorities to be an innovative medicinal product, and products may not qualify for data exclusivity. Even if a product is considered to be an innovative medicinal product so that the innovator gains the prescribed period of data exclusivity, another company may market another version of the product if such company obtained a marketing authorization based on a marketing authorization application with a complete, independent data package of pharmaceutical tests, preclinical tests and clinical trials.
 Products receiving orphan designation in the EU and being granted a marketing authorization for an orphan medicinal product can receive ten years of market exclusivity, during which time no similar medicinal product for the same indication may be placed on the market. A "similar medicinal product" is defined as a medicinal product containing a similar active substance or substances as contained in an authorized orphan medicinal product, and which is intended for the same therapeutic indication. An orphan product can also obtain an additional two years of market exclusivity in the EU where the application for a marketing authorization includes the results of all studies conducted in accordance with an agreed pediatric investigation plan for pediatric studies. No extension to any supplementary protection certificate can be granted on the basis of pediatric studies for orphan indications.
 The criteria for designating an "orphan medicinal product" in the EU are similar in principle to those in the United States. Under Article 3 of Regulation (EC) 141/2000, a medicinal product may be designated as orphan if (1) it is intended for the diagnosis, prevention or treatment of a life-threatening or chronically debilitating condition; (2) either (a) such condition affects no more than five (5) in ten thousand (10,000) persons in the EU when the

 application is made, or (b) it is unlikely that the product, without the benefits derived from orphan status, would not generate sufficient return in the EU to justify the necessary investment in its development; and (3) there exists no satisfactory method of diagnosis, prevention or treatment of such condition authorized for marketing in the EU, or if such a method exists, the product will be of significant benefit to those affected by the condition, as defined in Regulation (EC) 847/2000. Orphan medicinal products are eligible for financial incentives such as reduction of fees or fee waivers. The application for orphan drug designation must be submitted before the application for marketing authorization. The applicant will receive a fee reduction for the marketing authorization application if the orphan drug designation has been granted, but not if the designation is still pending at the time the marketing authorization is submitted. Orphan drug designation itself does not convey any advantage in, or shorten the duration of, the regulatory review and approval process.
 The 10-year market exclusivity may be reduced to six years if, at the end of the fifth year, it is established that the product no longer meets the criteria for orphan designation, for example, if the product is sufficiently profitable not to justify maintenance of market exclusivity. Additionally, a marketing authorization may be granted to a similar medicinal product for the same indication at any time if:
 • the second applicant can establish that its product, although similar, is safer, more effective or otherwise clinically superior;
 • the marketing authorization holder of the authorized product consents to a second orphan medicinal product application; or
 • the marketing authorization holder of the authorized product cannot supply enough orphan medicinal product.
 In the EU, the advertising and promotion of our products will also be subject to EU member states' laws concerning promotion of medicinal products, interactions with physicians, misleading and comparative advertising and unfair commercial practices, as well as other EU member state legislation that may apply to the advertising and promotion of medicinal products. These laws require that promotional materials and advertising in relation to medicinal products comply with the product's approved Summary of Product Characteristics, or SmPC. The SmPC is the document that provides information to physicians concerning the safe and effective use of the medicinal product. The off-label promotion of medicinal products is prohibited in the EU. The applicable laws at the EU level and in the individual EU member states also prohibit the direct-to-consumer advertising of prescription-only medicinal products. Violations of the rules governing the promotion of medicinal products in the EU could be penalized by administrative measures, fines and imprisonment. These laws may further limit or restrict communications concerning the advertising and promotion of our products to the general public and may also impose limitations on our promotional activities with healthcare professionals.
 Failure to comply with the EU member state laws implementing the EU laws on medicinal products, and EU rules governing the promotion of medicinal products, interactions with physicians, misleading and comparative advertising and unfair commercial practices, with the EU member state laws that apply to the promotion of medicinal products, statutory health insurance, bribery and anti-corruption or with other applicable regulatory requirements can result in enforcement action by the EU member state authorities (or in addition, in some member states, enforcement action from industry bodies or legal action from competitors), which may include any of the following: fines, imprisonment, orders forfeiting products or prohibiting or suspending their supply to the market, or requiring the manufacturer to issue public warnings, or to conduct a product recall.
 The national laws of certain EU member states require payments made to physicians to be publicly disclosed. Moreover, the European Federation of Pharmaceutical Industries and Associations, or EFPIA, Code on disclosure of transfers of value from pharmaceutical companies to healthcare professionals and healthcare organizations imposes a general obligation on members of the EFPIA or related national industry bodies to disclose transfers of value to healthcare professionals. In addition, agreements with physicians must often be the subject of prior notification and approval by the physician's employer, his/her competent professional organization, and/or the competent authorities of the individual EU member states. These requirements are provided in the national laws, industry codes, or professional codes of conduct, applicable in the EU member states.

 The aforementioned EU rules are generally applicable in the EEA, which consists of the EU member states, plus Norway, Liechtenstein and Iceland.
 For other countries outside of the EU, such as countries in Eastern Europe, Central and South America or Asia, the requirements governing the conduct of clinical trials, product licensing, pricing and reimbursement vary from country to country. This act could have implications for our interactions with physicians in and outside the UK. In all cases, again, the clinical trials are conducted in accordance with GCP, applicable regulatory requirements, and ethical principles that have their origin in the Declaration of Helsinki.
 If we fail to comply with applicable foreign regulatory requirements, we may be subject to, among other things, warning letters or untitled letters, injunctions, civil, administrative, or criminal penalties, monetary fines or imprisonment, suspension or withdrawal of regulatory approvals, suspension of ongoing clinical studies, refusal to approve pending applications or supplements to applications filed by us, suspension or the imposition of restrictions on operations, product recalls, the refusal to permit the import or export of our products or the seizure or detention of products.
 Pricing, Coverage and Reimbursement
 In the United States and markets in other countries, patients generally rely on third-party payers to reimburse all or part of the costs associated with their treatment. Adequate coverage and reimbursement from governmental healthcare programs, such as Medicare and Medicaid, and commercial payers is critical to new product acceptance. Our ability to successfully commercialize our product candidates will depend in part on the extent to which coverage and adequate reimbursement for these products and related treatments will be available from government health administration authorities, private health insurers and other organizations. Government authorities and third-party payers, such as private health insurers and health maintenance organizations, decide which medications they will pay for and establish reimbursement levels. If coverage and adequate reimbursement is not available, or is available only to limited levels, we may not be able to successfully commercialize our product candidates. Even if coverage is provided, the approved reimbursement amount may not be high enough to allow us to establish or maintain pricing sufficient to realize a sufficient return on our investment.
 Significant uncertainty exists as to the coverage and reimbursement status of any drug products for which we obtain regulatory approval. In the United States, the principal decisions about reimbursement for new medicines are typically made by the Centers for Medicare & Medicaid Services, or CMS, an agency within the United States Department of Health and Human Services. CMS decides whether and to what extent a new medicine will be covered and reimbursed under Medicare and private payers tend to follow CMS to a substantial degree. However, no uniform policy of coverage and reimbursement for drug products exists among third-party payers. Therefore, coverage and reimbursement for drug products can differ significantly from payer to payer. The process for determining whether a payer will provide coverage for a drug product may be separate from the process for setting the price or reimbursement rate that the payer will pay for the drug product. Third-party payers may limit coverage to specific drug products on an approved list, or formulary, which might not include all of the FDA-approved drugs for a particular indication. Third-party payers may provide coverage, but place stringent limitations on such coverage, such as requiring alternative treatments to be tried first. These third-party payers are increasingly challenging the price and examining the medical necessity and cost-effectiveness of medical products and services, in addition to their safety, efficacy, and overall value. In addition, significant uncertainty exists as to the reimbursement status of newly approved healthcare products. We may need to conduct expensive pharmacoeconomic studies in order to demonstrate the medical necessity and cost-effectiveness of our products, in addition to incurring the costs required to obtain FDA approvals. Our product candidates may not be considered medically reasonable or necessary or cost-effective. Factors payors consider in determining reimbursement are based on whether the product is:
 • a covered benefit under its health plan;
 • safe, effective and medically necessary;
 • appropriate for the specific patient;

 • cost-effective; and
 • neither experimental nor investigational.
 Different pricing and reimbursement schemes exist in other countries. In the EU, governments influence the price of drug products through their pricing and reimbursement rules and control of national health care systems that fund a large part of the cost of those products to consumers. Some jurisdictions operate systems under which products may be marketed only after a reimbursement price has been agreed. To obtain reimbursement or pricing approval, some of these countries may require the completion of studies or analyses of clinical trials that compare the cost-effectiveness of a particular product candidate to currently available therapies. Other member states allow companies to set their own prices for medicines, but exert cost controls in other ways, including but not limited to, placing revenue caps on product sales, providing reimbursement for only a subset of eligible patients, mandating price negotiations after a set period of time, or mandating that prices not exceed an average basket of prices in other countries. The downward pressure on health care costs in general, particularly treatments, has become very intense. As a result, increasingly high barriers are being erected to the entry of new products. In addition, European governments may periodically review and decrease prices based on factors, including but not limited to, years-on-market, price in other countries, competitive entry, new clinical data, lack of supporting clinical data, or other factors.
 The marketability of any products for which we receive regulatory approval for commercial sale may suffer if the government and third-party payers fail to provide adequate coverage and reimbursement. In addition, the emphasis on managed care in the United States has increased and we expect will continue to exert downward pressure on pharmaceutical pricing. Coverage policies, third-party reimbursement rates and pharmaceutical pricing regulations may change at any time. Even if favorable coverage and reimbursement status is attained for one or more products for which we receive regulatory approval, less favorable coverage policies and reimbursement rates may be implemented in the future.
 Healthcare Reform
 Payers, whether domestic or foreign, or governmental or private, are developing increasingly sophisticated methods of controlling healthcare costs and those methods are not always specifically adapted for new technologies such as gene therapy and therapies addressing rare diseases such as those we are developing. In both the United States and certain foreign jurisdictions, there have been a number of legislative and regulatory changes to the health care system that could impact our ability to sell our products profitably. In particular, in 2010, the Patient Protection and Affordable Care Act, as amended by the Health Care and Education Reconciliation Act of 2010, or collectively, the ACA, was enacted, which, among other things, subjected biologic products to potential competition by lower-cost biosimilars; increased the minimum Medicaid rebates owed by most manufacturers under the Medicaid Drug Rebate Program; extended the Medicaid Drug Rebate program to utilization of prescriptions of individuals enrolled in Medicaid managed care organizations; subjected manufacturers to new annual fees and taxes for certain branded prescription drugs; created a new Medicare Part D coverage gap discount program, in which manufacturers must agree to offer 70% point-of-sale discounts off negotiated prices of applicable brand drugs to eligible beneficiaries during their coverage gap period, as a condition for the manufacturer's outpatient drugs to be covered under Medicare Part D; and provided incentives to programs that increase the federal government's comparative effectiveness research.
 In addition, other legislative and regulatory changes have been proposed and adopted in the United States since the ACA was enacted:
 • The U.S. Budget Control Act of 2011, among other things, included aggregate reductions of Medicare payments to providers of 2% per fiscal year. Subsequent legislation extended the 2% payment reduction which remains in effect through 2031.
 • On January 2, 2013, the U.S. American Taxpayer Relief Act of 2012 was signed into law, which further reduced Medicare payments to several types of providers and increased the statute of limitations period for the government to recover overpayments to providers from three to five years.

 • On April 13, 2017, CMS published a final rule that gives states greater flexibility in setting benchmarks for insurers in the individual and small group marketplaces, which may have the effect of relaxing the essential health benefits required under the ACA for plans sold through such marketplaces.
 • On May 23, 2019, CMS published a final rule to allow Medicare Advantage Plans the option of using step therapy for Part B drugs beginning January 1, 2020.
 • On March 11, 2021, President Biden signed the American Rescue Plan Act of 2021 into law. Due to the Statutory Pay-As-You-Go Act of 2010, estimated budget deficit increases resulting from the American Rescue Plan Act of 2021, and subsequent legislation, Medicare payments to providers were further reduced starting on January 1, 2025; however, legislation has been introduced in the U.S. Congress that would, if enacted, reverse these payment reductions. In addition to provider payment cuts under Medicare, the American Rescue Plan Act of 2021 also eliminated the statutory Medicaid drug rebate cap, previously set at 100% of a drug's average manufacturer price, for single source and innovator multiple source drugs, beginning January 1, 2024. These laws and regulations may result in additional reductions in Medicare and other healthcare funding available for healthcare providers and may otherwise affect the prices we may obtain for any of our product candidates for which we may obtain regulatory approval or the frequency with which any such product candidate is prescribed or used.
 Additionally, there has been increasing legislative and enforcement interest in the United States with respect to drug pricing practices. Specifically, there has been heightened governmental scrutiny over the manner in which manufacturers set prices for their marketed products, which has resulted in several U.S. Congressional inquiries and proposed and enacted federal and state legislation designed to, among other things, bring more transparency to drug pricing, reduce the cost of prescription drugs under Medicare, and review the relationship between pricing and manufacturer patient programs. At a federal level, President Trump reversed some of President Biden's executive orders including rescinding Executive Order 14087 entitled "Lowering Prescription Drug Costs for Americans." President Trump may issue new executive orders designed to impact drug pricing. A number of these and other proposed measures may require authorization through additional legislation to become effective. Congress and the Trump administration have indicated that they will continue to seek new legislative measures to control drug costs.
 The Inflation Reduction Act of 2022, or IRA, includes several provisions that may impact our business to varying degrees, including provisions that reduce the out-of-pocket cap for Medicare Part D beneficiaries to $2,000 starting in 2025; impose new manufacturer financial liability on certain drugs under Medicare Part D, allow the U.S. government to negotiate Medicare Part B and Part D price caps for certain high-cost drugs and biologics without generic or biosimilar competition, require companies to pay rebates to Medicare for certain drug prices that increase faster than inflation, and delay the rebate rule that would limit the fees that pharmacy benefit managers can charge. Further, under the IRA, orphan drugs are exempted from the Medicare drug price negotiation program, but only if they have one orphan designation and for which the only approved indication is for that disease or condition. If a product receives multiple orphan designations or has multiple approved indications, it may not qualify for the orphan drug exemption. The implementation of the IRA is currently subject to ongoing litigation challenging the constitutionality of the IRA's Medicare drug price negotiation program. The effects of the IRA on our business and the healthcare industry in general is not yet known.
 Federal, state and local governments in the United States and foreign governments continue to consider other legislation to limit the growth of healthcare costs, including the cost of prescription drugs. Specifically, there have been several recent United States Congressional inquiries and proposed federal and state legislation designed to, among other things, bring more transparency to drug pricing, reduce the cost of prescription drugs under Medicare, review the relationship between pricing and manufacturer patient programs, and reform government program reimbursement methodologies for drugs.
 In addition, there have been several changes to the 340B drug pricing program, which imposes ceilings on prices that drug manufacturers can charge for medications sold to certain health care facilities. On November 3, 2023, the U.S. District Court of South Carolina issued an opinion in Genesis Healthcare Inc. v. Becerra et al. that may lead to an expansion of the scope of patients eligible to access prescriptions at 340B pricing. The outcome of this judicial proceeding is uncertain. We continue to review developments impacting the 340B program.

 At the state level, legislatures have increasingly passed legislation and implemented regulations designed to control pharmaceutical product pricing, including price or patient reimbursement constraints, discounts, restrictions on certain product access and marketing cost disclosure and transparency measures, and, in some cases, designed to encourage importation from other countries and bulk purchasing. We expect that additional state and federal healthcare reform measures will be adopted in the future, any of which could limit the amounts that federal and state governments will pay for healthcare products and services, which could result in reduced demand for our product candidates or additional pricing pressures.
 Human Capital Resources
 As of February 1, 2025, we employ approximately 65 full-time employees. To allow us flexibility in meeting varying workflow demands, we also engage consultants and temporary workers when needed. None of our employees are subject to a collective bargaining agreement or represented by a trade or labor union. We consider our employee relations to be good.
 In September 2023, we announced a reduction in workforce of approximately 40% in connection with a strategic restructuring. In January 2024, we announced a strategic path forward to focus exclusively on the commercialization and development of Abecma. In connection with our strategic re-alignment, we entered into an asset purchase agreement with Regeneron to sell our oncology and autoimmune research and development programs, clinical manufacturing capabilities, and related platform technologies which closed on April 1, 2024. Approximately 62% of the workforce that was left following completion of the 2023 Restructuring Plan transitioned to Regeneron as a part of the Regeneron Transaction. Additionally, as part of the strategic re-alignment, our board of directors approved a restructuring plan to further reduce its remaining workforce by approximately 14%.
 Compensation and benefits programs
 Our compensation programs are designed to align our employees' interests with the drivers of growth and stockholder returns by supporting our achievement of its primary business goals. Our goal is to attract and retain employees whose talents, expertise, leadership, and contributions are expected to sustain growth and drive long-term stockholder value. We are committed to providing comprehensive benefit options and it is our intention to offer benefits that will allow our employees and their families to live healthier and more secure lives, with a focus on both physical and mental well-being. All full-time employees are eligible for medical, dental, and vision insurance, paid time off, paid and unpaid leaves, an employee stock purchase plan, a 401(k) plan, and group life and disability coverage.
 Employee development and training
 The development, recruitment and retention of our employees is a critical success factor for our company. To ensure we provide a meaningful experience for our employees, we intend to offer training and development programs to increase our organizational learning and support the promotion and career development of our current employees.
 Diversity
 At 2seventy bio, we believe that it's about time that Diversity, Equity, Inclusion and Belonging become more than words. It is the core practice we are driven by in all we create. From our focus on patients, to how we are building our business and our culture, we believe diversity and belonging empower us to change the way we think, teach, and learn — from each other and about each other. Our mission is rooted in the belief that our cumulative and unique differences enable us to become better — better at our development of revolutionary scientific advancements and how we advance health equity by addressing cancer disparities with a goal of creating transformative treatments for those who need them. We strive to build an environment where we will deliver our best — that means having the hard conversations and doing the hard work — so we can all be unencumbered and inspired to celebrate who we are fully as human beings.

 Corporate Information
 We were incorporated under the laws of the state of Delaware in April 2021. Our mailing address and executive offices are located at 60 Binney Street, Cambridge, Massachusetts, 02142 and our telephone number at that address is (617) 675-7270.
 Available Information
 We intend to use our website www.2seventybio.com as a means of disclosing material non-public information and for complying with disclosure obligations under the SEC, Regulation FD. The information on our website is not incorporated by reference in this Annual Report or in any other filings we make with the SEC.
 We make available on or through our website certain reports and amendments to those reports that we file with or furnish to the SEC in accordance with the Securities Exchange Act of 1934, as amended. These include our annual reports on Form 10-K, our quarterly reports on Form 10-Q, and our current reports on Form 8-K, exhibits and amendments to those reports filed or furnished pursuant to Section 13(a) or 15(d) of the Exchange Act. We make this information available on or through our website free of charge as soon as reasonably practicable after we electronically file the information with, or furnish it to, the SEC.
 A copy of our Corporate Governance Guidelines, Code of Business Conduct and Ethics and the charters of the Audit Committee, Compensation Committee and Nominating and Corporate Governance Committee are posted on our website at  under "Investors & Media – Corporate Governance."
 The SEC maintains an Internet website that contains reports, proxy and information statements, and other information regarding us and other issuers that file electronically with the SEC. The SEC's Internet website address is

 Item 1A. Risk Factors
 An investment in shares of our common stock involves a high degree of risk. You should carefully consider the following information about these risks, together with the other information appearing elsewhere in this Annual Report, including our financial statements and related notes hereto, before deciding to invest in our common stock. The occurrence of any of the following risks could have a material adverse effect on our business, financial condition, results of operations and future growth prospects. In these circumstances, the market price of our common stock could decline, and you may lose all or part of your investment.
 Risks Related to the Proposed BMS Transaction
 The proposed acquisition by BMS is subject to a number of conditions beyond our control. Failure to complete the proposed acquisition within the expected time frame, or at all, could have a material adverse effect on our business, operating results, financial condition and our stock price.
 On March 10, 2025, we entered into the BMS Merger Agreement, pursuant to which, and upon the terms and subject to the conditions thereof, Daybreak Merger Sub Inc. (a wholly-owned subsidiary of BMS) ("Merger Sub") will commence a cash tender offer to acquire all of our issued and outstanding shares of common stock at a price per share of $5.00 per share, without interest and subject to any withholding of taxes required by applicable law. In the event the tender offer conditions are satisfied and the tender offer is closed, upon the terms and subject to the conditions set forth in the BMS Merger Agreement, Merger Sub will merge with and into us, with our company continuing as the surviving corporation and as a wholly owned subsidiary of BMS. Upon completion of these transactions, we will no longer be a publicly traded company, and the listing of our common stock on Nasdaq will have been terminated. Refer to Note 20 to our Consolidated Financial Statements for a summary of the terms of the BMS Merger Agreement, the transactions provided for thereunder, and the various conditions to closing the transaction. As described in Note 20, the obligation of BMS and Merger Sub to consummate the tender offer is subject to certain conditions, including the condition that there be validly tendered and not withdrawn prior to the expiration of the offer a number of shares of common stock that, together with the shares of common stock then owned by BMS or its affiliates, represents at least one more than 50% of the total number of shares of our common stock issued and outstanding at the time of expiration of the tender offer. The obligation of BMS to consummate the offer is also subject to other conditions, including the receipt of required clearances under applicable antitrust laws and other customary conditions.
 We cannot predict whether and when the conditions to closing will be satisfied. Until these conditions are satisfied and we complete proposed transaction, our business, operating results and financial condition are exposed to certain risks due to the effect of the pending transaction, including:
 • the possibility of disruption to our business and operations, including diversion of management attention and resources;
 • the inability to attract and retain key personnel, and the possibility that our current employees could be distracted, and their productivity decline as a result;
 • the inability to pursue alternative business opportunities or make changes to our business pending the completion of the transaction, and other restrictions on our ability to conduct our business;
 • the amount of the costs, fees, expenses, and charges related to the transaction;
 • our inability to solicit other acquisition proposals; and
 • the market price of our common stock could decrease if the proposed transaction is not completed or if there exists a market perception that the transaction will not be completed.
 If the transaction does not close, we would be exposed to additional risks, including:
 • to the extent the current market price of our common stock reflects an assumption that the transaction will be completed, the price of our common stock could decrease if the transaction is not completed;

 • investor confidence could decline, shareholder litigation could be brought against us, relationships with service providers, investors, and other business partners (including BMS as our collaboration partner on Abecma) may be adversely impacted, we may be unable to retain key personnel, and our financial condition may be adversely impacted due to costs incurred in connection with the pending transaction; and
 • the requirement that we pay a termination fee of $10,000,000 if the BMS Merger Agreement is terminated in certain circumstances, including if we terminate to accept and enter into an agreement with respect to a superior proposal.
 Risks Related to Our Financial Position and Capital Needs
 Our business has incurred significant losses and we anticipate that we will incur continued losses for the near future. We have never recognized revenue from product sales and may never be profitable.
 Our business has incurred operating losses due to costs incurred in connection with our research and development activities and general and administrative expenses associated with our operations. Our net losses for the years ended December 31, 2024 and 2023 were $57.2 million and $217.6 million, respectively.
 The amount of our future net losses will depend, in part, on the rate of our future expenditures and our ability to recognize revenues. Our current and future revenues will depend upon the size of any markets in which Abecma has received approval, and our ability to achieve sufficient market acceptance, reimbursement from third-party payors and adequate market share for Abecma in those markets.
 We expect to continue to incur significant expenses and continued operating losses in the near future. We anticipate that our expenses will increase if and as we:
 • conduct commercialization activities for Abecma;
 • maintain, protect and expand our intellectual property portfolio;
 • attract and retain skilled personnel; and
 • experience any delays or encounter issues with any of the above.
 Our expenses could increase beyond expectations if we are required by the FDA, the European Medicines Agency, or the EMA, or other regulatory agencies, domestic or foreign, to perform clinical and other studies in addition to those that we currently anticipate. Even though Abecma has been approved by the FDA for commercial sale and we receive a 50% share of all revenue from sales of Abecma in the United States pursuant to our collaboration with BMS, we may never recognize revenue in amounts sufficient to achieve and maintain profitability. The net losses we incur may fluctuate significantly from quarter to quarter and year to year, such that a period-to-period comparison of our results of operations may not be a good indication of our future performance. In any particular quarter or quarters, our operating results could be below the expectations of securities analysts or investors, which could cause our stock price to decline.
 We will need to raise additional funding to commercialize Abecma, which may not be available on acceptable terms, or at all. Failure to obtain capital when needed may force us to delay, limit or terminate development or commercialization efforts or other operations. Raising additional capital may dilute our existing stockholders, restrict our operations or cause us to relinquish valuable rights.
 As of December 31, 2024, we held cash, cash equivalents and marketable securities of $183.6 million. If the merger with BMS does not close, we may require additional funding to continue to advance Abecma or pursue additional indications for Abecma, alone or with strategic partners, through additional clinical studies. We also may elect to raise additional funds sooner because we believe market conditions are attractive or as a risk mitigation measure.
 Any additional fundraising efforts may divert our management from their day-to-day activities, which may adversely affect our ability to develop and commercialize Abecma. In addition, we cannot guarantee that financing

 will be available in sufficient amounts or on terms acceptable to us, if at all. Moreover, the terms of any financing may adversely affect the holdings or the rights of our stockholders and the issuance of additional securities, whether equity or debt, by us, or the possibility of such issuance, may cause the market price of our shares to decline. The sale of additional equity or convertible securities would dilute all of our stockholders. The incurrence of indebtedness would result in increased fixed payment obligations and we may be required to agree to certain restrictive covenants, such as limitations on our ability to incur additional debt, limitations on our ability to acquire, sell or license intellectual property rights and other operating restrictions that could adversely impact our ability to conduct our business. We could also be required to seek funds through arrangements with collaborative partners or otherwise at an earlier stage than otherwise would be desirable and we may be required to agree to terms unfavorable to us, any of which may have a material adverse effect on our business, operating results and prospects. Regardless of the terms of any debt or equity financing, our agreements and obligations under the tax matters agreement with bluebird bio, may limit our ability to issue stock. See "—Risks Related to the Separation."
 If we are unable to obtain funding on a timely basis, or if revenues from collaboration arrangements or product sales are less than we have projected, we may be required to significantly curtail, delay or discontinue development programs for the commercialization of Abecma or be unable to expand our operations or otherwise capitalize on our business opportunities as desired, which could materially affect our business, financial condition and results of operations. In addition, if we are unable to obtain necessary funding on a timely basis, we may have to liquidate some or all of our assets and may receive less than the value at which those assets are carried on our audited financial statements, which could cause investors to lose all or a part of their investment.
 Because we have a limited operating history, valuing our business and predicting our prospects is challenging.
 We were incorporated in April 2021 and separated from bluebird bio in November 2021. Although our business was conducted as part of bluebird bio prior to our separation, we did not operate as an independent company prior to the completion of the separation. The FDA granted approval of Abecma to BMS, our partner with whom we are jointly commercializing Abecma in the U.S. through our co-development and co-promotion arrangement. Our revenues to date have been derived from out-licensing arrangements and collaboration, including the collaboration revenue derived from commercial sales of Abecma by BMS. To date, we have not recognized any revenues from the sale of products by us. Our operating activities to date have been limited primarily to organizing and staffing our company, business planning, raising capital, developing our technology, identifying potential product candidates and clinical trial activities.
 We, together with BMS, have limited experience in the sales and marketing activities necessary for the commercialization of Abecma. Our short operating history offers limited insight into our prospects for success or even viability and we expect our operating results to be subject to frequent fluctuations. We will encounter challenges frequently experienced by biopharmaceutical companies in rapidly evolving fields, and we have not yet demonstrated an ability to successfully navigate such challenges. If we do not address the challenges we face successfully, our business, prospects, financial condition and results of operations will be materially harmed.
 Risks Related to Strategic Realignment
 Our strategic realignment to focus on the development and commercialization of Abecma may not be as successful as anticipated, fail to achieve the anticipated cost savings, and cause disruptions in our business that could make it difficult to achieve our strategic objectives.
 In January 2024, we announced a strategic realignment to focus on the development and commercialization of Abecma. In connection with the strategic realignment, the Asset Sale closed on April 1, 2024. We also entered into an asset purchase agreement with Novo to sell substantially all of the assets related to our megaTAL platform and the Novo Transaction closed in June 2024. We have limited experience implementing similar strategic initiatives and, as a result, we may fail to achieve the associated benefits, or fail to anticipate the associated costs or manage any expected difficulties. If we are unable to successfully manage these realignment activities, our financial performance, results of operations, and prospects could be negatively affected. In addition, the impact of these initiatives could result in variations in our financial results from period to period, which could make comparisons of our financial performance more difficult.

 We have recently undertaken internal restructuring activities including reductions in the workforce, and may do so again in the future. The assumptions underlying these activities may prove to be inaccurate, or we may fail to achieve the expected benefits.
 In September 2023, we announced a reduction in workforce of approximately 40% in connection with a strategic restructuring and in January 2024, we announced a reduction in workforce of approximately 14% in connection with a strategic realignment to focus on the development and commercialization of Abecma. These workforce reductions, and any other future reductions, and the attrition that may occur following them, may result in the loss of institutional knowledge and expertise and the reallocation and combination of certain roles and responsibilities across the organization, all of which could adversely affect our operations. These reductions and other additional measures we might take to reduce costs could yield unanticipated consequences, such as straining our workforce, diverting management attention, yielding attrition beyond our intended workforce reduction, or reducing employee morale. These unintended effects could cause us to delay, limit, reduce or eliminate certain development plans, or otherwise interfere with our ability to operate and grow our business effectively, which could have an adverse impact on our business, operating results and financial condition. We may not complete current or any future restructuring activities on the anticipated timetable, and even if successfully completed, we may not realize, in full or in part, the anticipated benefits and cost savings from our restructuring efforts due to unforeseen difficulties, delays or unexpected costs. If we are unable to realize the expected cost savings from the restructuring, our operating results and financial condition would be adversely affected. We also cannot guarantee that we will not have to undertake additional workforce reductions or restructuring activities in the future.
 Risks Related to the Discovery, Product Development and Regulatory Approval
 If the market opportunities for Abecma or any future approved products are smaller than we believe they are, and if we are not able to successfully identify patients and achieve significant market share, our revenues may be adversely affected and our business may suffer.
 We focus our development and commercialization efforts on treatments for cancer. Our projections of both the number of people who have these diseases, as well as the subset of people with these diseases who have the potential to benefit from treatment with Abecma or any future approved products, are based on estimates. These estimates have been derived from a variety of sources, including scientific literature, surveys of clinics, patient foundations, or market research, and may prove to be incorrect. Further, new studies may change the estimated incidence or prevalence of these diseases. The number of patients may turn out to be lower or more difficult to identify than expected. Additionally, the potentially addressable patient population for Abecma and any future approved products may be limited or may not be amenable to treatment with our products.
 Even if we obtain significant market share for within an approved indication, because the potential target populations for Abecma is small, we may never achieve profitability without obtaining marketing approval for additional indications. In the field of cancer, the FDA often approves new therapies initially only for use in patients with relapsed or refractory advanced disease. There is no guarantee that future product candidates, even if approved, would be approved for earlier lines of therapy, and, prior to any such approvals, we may have to conduct additional clinical trials. For example, BMS received marketing approval from the FDA for Abecma as a treatment for adult patients with relapsed and refractory multiple myeloma who have not responded to, or whose disease has returned after, at least four prior lines of therapy. In April 2024, based on the results of the KarMMA-3 study, the FDA approved Abecma for the treatment of adult patients with relapsed or refractory multiple myeloma after two or more prior lines of therapy including an immunomodulatory agent, a proteasome inhibitor, and an anti-CD38 monoclonal antibody.
 Any of these factors may negatively affect our ability to recognize revenues from sales of Abecma and any future products and our ability to achieve and maintain profitability and, as a consequence, our business may suffer.
 If the marketing approval of Abecma and any future approved products is ultimately for more narrow indications than we expect, our business prospects, results of operations, and financial condition would be adversely affected.
 Before obtaining marketing approval from regulatory authorities for the commercialization of Abecma in additional indications, we must complete extensive clinical studies to demonstrate the safety, purity and potency,

 and efficacy, of the product candidate in humans in such indications, which is expensive, time-consuming, uncertain as to outcome and subject to a high failure rate. We cannot guarantee that any clinical studies would be conducted as planned or completed on schedule, if at all. A failure of one or more clinical studies can occur at any stage of testing. Events that may prevent successful or timely completion of clinical development include:
 • we may be unable to demonstrate to the satisfaction of the FDA or comparable foreign regulatory authorities that a product is safe and effective for its proposed indication;
 • the results of clinical trials may not meet the level of statistical significance required by the FDA or comparable foreign regulatory authorities for approval;
 • data collected from clinical trials may not be sufficient to support the submission or to obtain regulatory approval;
 • delays in reaching, or failure to reach, a consensus with regulatory agencies on study design;
 • imposition of a clinical hold by regulatory agencies, after an inspection of our clinical study operations or study sites or due to unforeseen safety issues;
 • delays in the testing, validation, manufacturing and delivery of our product candidates to the clinical sites;
 • failure to obtain sufficient cells from patients to manufacture enough drug product or achieve target cell doses;
 • delays in having patients complete participation in a study or return for post-treatment follow-up;
 • delays or difficulties in initiating clinical study sites or patients dropping out of a study;
 • occurrence of serious adverse events associated with the product candidate that are viewed to outweigh its potential benefits; or
 • changes in regulatory requirements and guidance that require amending or submitting new clinical protocols.
 Furthermore, the timing of our clinical studies depends on the speed at which we can recruit eligible patients to participate, and we may experience delays if we encounter difficulties in recruitment or enrollment. The eligibility criteria of our clinical studies will further limit the pool of available study participants, and the process of finding and diagnosing patients may prove costly. Patients may be unwilling to participate in our studies because of negative publicity from adverse events in the biotechnology or gene therapy industries or for other reasons, including competitive clinical studies for similar patient populations, the proximity and availability of clinical study sites for prospective patients, and the patient referral practices of physicians. If patients are unwilling to participate in our studies for any reason, the timeline for recruiting patients, conducting studies, and obtaining regulatory approval for our product candidates may be delayed. We may not be able to identify, recruit and enroll a sufficient number of patients, or those with required or desired characteristics to achieve diversity in a study, to complete our clinical studies in a timely manner or as required by the FDA or comparable foreign regulatory authorities. We have experienced delays in some of our clinical studies in the past, and we may experience similar delays in the future.
 Even if Abecma demonstrates safety and efficacy in additional indications in clinical studies, regulatory delays or rejections may be encountered as a result of many factors, including changes in regulatory policy during the period of product development. We may experience delays or rejections based upon additional government regulation from future legislation or administrative action, changes in regulatory agency policy, or additional regulatory feedback or guidance during the period of product development, clinical studies and the review process. The field of engineered cell therapy is evolving, and as more products are reviewed by regulatory authorities, regulatory authorities may impose additional requirements that were not previously anticipated. Regulatory agencies also may approve a treatment candidate for fewer or more limited indications than requested, impose significant limitations in the form of narrow indications, warnings, or a REMS, or may grant approval subject to the performance of post-marketing studies. In addition, regulatory agencies may not approve the labeling claims that are

 necessary or desirable for the successful commercialization of our product candidates. Furthermore, approvals by the EMA and the European Commission may not be indicative of what the FDA may require for approval. In general, the FDA requires the successful completion of two pivotal trials to support approval of a BLA, but in certain circumstances, will approve a BLA based on only one pivotal trial. Additionally, certain factors beyond our and our collaborators' control may impact the timeliness of the regulatory reviews of our submissions or any applications for approval.
 We could encounter delays if a clinical trial is suspended or terminated by us, by the IRBs of the institutions in which such trials are being conducted, by a Data Safety Monitoring Board, or DSMB, for such trial or by the FDA or comparable foreign regulatory authorities. Such authorities may impose such a suspension or termination due to a number of factors, including failure to conduct the clinical trial in accordance with regulatory requirements or our clinical trial protocols, inspection of the clinical trial operations or trial site by the FDA or comparable foreign regulatory authorities resulting in the imposition of a clinical hold, unforeseen safety issues or adverse side effects, failure to demonstrate a benefit from using a drug, changes in governmental regulations or administrative actions or lack of adequate funding to continue the clinical trial. If we experience delays in the completion of, or termination of, any clinical trial of our product candidates, the commercial prospects of our product candidates will be harmed, and our ability to recognize product revenues from any of these product candidates will be delayed. In addition, any delays in completing our clinical trials will increase our costs, slow down the development and approval process and jeopardize our ability to commence product sales and recognize revenues for these product candidates.
 Any of these occurrences may harm our business, financial condition, results of operations and prospects significantly. In addition, many of the factors that cause, or lead to, a delay in the commencement or completion of clinical trials may also ultimately lead to the denial of regulatory approval of Abecma in additional indications.
 Research and development of biopharmaceutical products is inherently risky. We may encounter substantial delays in our clinical studies, or we may fail to demonstrate safety and efficacy to the satisfaction of applicable regulatory authorities.
 Our business depends heavily on successful clinical development, regulatory approvals and commercialization of Abecma. Any future product candidates will require substantial additional development and testing, as well as regulatory approvals, prior to commercialization.
 Before obtaining regulatory approvals for the commercial sale of any product candidates, we must demonstrate through lengthy, complex and expensive preclinical and clinical studies that our product candidates are both safe and effective for use in each target indication. Each product candidate must demonstrate an adequate benefit-risk profile for its intended use in its intended patient population. Failure can occur at any time during the preclinical study and clinical trial processes. In some instances, significant variability in safety or efficacy appear in different clinical studies of the same product candidate due to numerous factors, including changes in study protocols, differences in the number and characteristics of the enrolled subjects, variations in the dosing regimen and other clinical study parameters or the dropout rate among study participants. Product candidates in later stages of clinical studies often fail to demonstrate adequate safety and efficacy despite encouraging preclinical study and earlier clinical trial results. A number of companies in the biopharmaceutical industry have suffered significant setbacks in later-stage clinical studies. Most product candidates that begin clinical studies are never approved for commercialization by regulatory authorities. If the results of future clinical trials are inconclusive with respect to the safety and efficacy of product candidates, if we do not meet the clinical endpoints with statistical and clinically meaningful significance, or if there are safety concerns associated with any product candidate, we may be prevented or delayed in obtaining marketing approval for such product candidates

 Where appropriate, we may seek approval from the FDA, EMA or comparable foreign regulatory authorities through the use of accelerated approval pathways. If we are unable to obtain such approval, we may be required to conduct additional preclinical studies or clinical trials beyond those that we contemplate, which could increase the expense of obtaining, and delay the receipt of, necessary marketing approvals. Even if we receive accelerated approval from the FDA, EMA or comparable regulatory authorities, if our confirmatory trials do not verify

 clinical benefit, or if we do not comply with rigorous post-marketing requirements, the FDA, EMA or such other regulatory authorities may seek to withdraw the accelerated approval.
 Where possible, we may pursue accelerated development strategies in areas of high unmet need. We may seek an accelerated approval pathway for our one or more of our product candidates from the FDA, EMA or comparable foreign regulatory authorities. Under the accelerated approval provisions in the Federal Food, Drug, and Cosmetic Act, and the FDA's implementing regulations, the FDA may grant accelerated approval to a therapeutic candidate designed to treat a serious or life-threatening condition that provides meaningful therapeutic benefit over available therapies upon a determination that the product candidate has an effect on a surrogate endpoint or intermediate clinical endpoint that is reasonably likely to predict clinical benefit. The FDA considers a clinical benefit to be a positive therapeutic effect that is clinically meaningful in the context of a given disease, such as irreversible morbidity or mortality. For the purposes of accelerated approval, a surrogate endpoint is a marker, such as a laboratory measurement, radiographic image, physical sign, or other measure that is thought to predict clinical benefit, but is not itself a measure of clinical benefit. An intermediate clinical endpoint is a clinical endpoint that can be measured earlier than an effect on irreversible morbidity or mortality that is reasonably likely to predict an effect on irreversible morbidity or mortality or other clinical benefit. The accelerated approval pathway may be used in cases in which the advantage of a new drug over available therapy may not be a direct therapeutic advantage, but is a clinically important improvement from a patient and public health perspective. If granted, accelerated approval is usually contingent on the sponsor's agreement to conduct, in a diligent manner, additional post-approval confirmatory studies to verify and describe the drug's clinical benefit, and the FDA is permitted to require, as appropriate, that such studies be underway prior to approval or within a specified period after the date of approval. Sponsors must also update FDA on the status of these studies, and under the FDORA, the FDA has increased authority to withdraw approval of a drug granted accelerated approval on an expedited basis if the sponsor fails to conduct such studies in a timely manner, send the necessary updates to the FDA, or if such post-approval studies fail to verify the drug's predicted clinical benefit.
 Prior to seeking accelerated approval, we will seek feedback from the FDA, EMA or comparable foreign regulatory authorities and will otherwise evaluate our ability to seek and receive such accelerated approval. There can be no assurance that after our evaluation of the feedback and other factors we will decide to pursue or submit a BLA for accelerated approval or any other form of expedited development, review or approval. Similarly, there can be no assurance that after subsequent feedback from the FDA, EMA or comparable foreign regulatory authorities, we will continue to pursue or apply for accelerated approval or any other form of expedited development, review or approval, even if we initially decide to do so. Furthermore, if we decide to submit an application for accelerated approval, there can be no assurance that such application will be accepted or that any approval will be granted on a timely basis, or at all. The FDA, EMA or other comparable foreign regulatory authorities could also require us to conduct further studies prior to considering our application or granting approval of any type, including, for example, if other products are approved via the accelerated pathway and subsequently converted by FDA to full approval. A failure to obtain accelerated approval or any other form of expedited development, review or approval for our product candidate would result in a longer time period to commercialization of such product candidate, could increase the cost of development of such product candidate and could harm our competitive position in the marketplace. Moreover, even if we are able to obtain accelerated approval for any of our product candidates, there is no guarantee that post-approval studies will be able to confirm the clinical benefit, which could cause FDA to withdraw our approval.
 The regulatory approval processes of the FDA and comparable foreign regulatory authorities are lengthy, time-consuming and inherently unpredictable. If we are ultimately unable to obtain regulatory approval for our future product candidates, or if BMS is ultimately unable to obtain regulatory approvals for Abecma in additional indications, we will be unable to recognize product revenue and our business will be substantially harmed.
 We cannot commercialize a product until the appropriate regulatory authorities have reviewed and approved the product candidate. The time required to obtain approval by the FDA and comparable foreign regulatory authorities is unpredictable, typically takes many years following the commencement of clinical studies and depends upon numerous factors, including the type, complexity, and novelty of the product candidates involved. Regulatory authorities have substantial discretion in the approval process and may refuse to accept an application for review, or may decide that our data are insufficient for approval and require additional preclinical, clinical or other studies.

 In September 2020, the FDA accepted for priority review the BLA submitted by BMS for Abecma (ide-cel) as a treatment for adults with multiple myeloma who have received at least four prior lines of therapy, including an immunomodulatory agent, a proteasome inhibitor and an anti-CD38 (cyclic ADP ribose hydrolase) monoclonal antibody. Obtaining one regulatory approval does not guarantee that the FDA will approve a product for additional or expanded indications. Additionally, certain factors beyond our and BMS' control may impact the timeliness of the regulatory reviews of our submissions or any applications for approval.
 We may never be able to obtain regulatory approval for any other product candidates. If our product candidates, including Abecma for additional indications, are ultimately not approved for any reason, our business, prospects, results of operations and financial condition would be adversely affected.
 Clinical studies may not begin on schedule and may not be completed on schedule, if at all. The completion or commencement of clinical studies can be delayed or prevented for a number of reasons, including, among others:
 • the FDA or comparable foreign regulatory authorities may not authorize us or our investigators to commence planned clinical studies, or require that we suspend ongoing clinical studies through imposition of clinical holds;
 • negative results from our ongoing studies or other industry studies involving engineered cell therapy product candidates;
 • delays in reaching or failing to reach agreement on acceptable terms with prospective CROs and clinical study sites, the terms of which can be subject to considerable negotiation and may vary significantly among different CROs and study sites;
 • inadequate quantity or quality of a product candidate or other materials necessary to conduct clinical studies, for example delays in the manufacturing of sufficient supply of finished drug product;
 • difficulties obtaining ethics committee or IRB, approval to conduct a clinical study at a prospective site or sites;
 • challenges in recruiting and enrolling subjects to participate in clinical studies, the proximity of subjects to study sites, eligibility criteria for the clinical study, the nature of the clinical study protocol, the availability of approved effective treatments for the relevant disease and competition from other clinical study programs for similar indications;
 • severe or unexpected drug-related side effects experienced by subjects in a clinical study, such as severe neurotoxicity and cytokine release syndrome;
 • we may decide, or regulatory authorities may require us, to conduct additional clinical studies or abandon product development programs;
 • the FDA or comparable foreign regulatory authorities may disagree with our clinical study design, implementation of clinical trials or our interpretation of data from clinical studies, or may change the requirements for approval even after it has reviewed and commented on the design for our clinical studies;
 • reports from preclinical or clinical testing of other competing candidates that raise safety or efficacy concerns; and
 • difficulties retaining subjects who have enrolled in a clinical study but may be prone to withdraw due to rigors of the clinical studies, lack of efficacy, side effects, personal issues, or loss of interest.
 Clinical studies may also be delayed or terminated as a result of ambiguous or negative interim results. In addition, a clinical study may be suspended or terminated by us, the FDA or other comparable authorities, the IRBs or ethic committees at the sites where the IRBs or ethic committees are overseeing a clinical study, a data and safety monitoring board overseeing the clinical study at issue or other regulatory authorities due to a number of factors, including, among others:

 • failure to conduct the clinical study in accordance with regulatory requirements or our clinical protocols;
 • inspection of the clinical study operations or study sites by the FDA or other regulatory authorities that reveals deficiencies or violations that require us to undertake corrective action, including in response to the imposition of a clinical hold;
 • unforeseen safety issues, including any that could be identified in our ongoing studies, adverse side effects or lack of effectiveness;
 • changes in government regulations or administrative actions;
 • problems with clinical supply materials; and
 • lack of adequate funding to continue clinical studies.
 In addition, regulatory agencies may not approve the labeling claims that are necessary or desirable for the successful commercialization of our product candidates. Even if regulatory approval is secured for any of our product candidates, the terms of such approval may limit the use of any approved product, which will limit its prospects for commercialization, which could have a material and adverse effect on our business, prospects, financial condition and results of operations.
 Inadequate funding for the FDA, the SEC and other U.S. government agencies or the EMA or comparable foreign regulatory authorities, including from government shut downs, or other disruptions to these agencies' operations, including significant leadership, personnel, and policy changes, could prevent those agencies from performing normal business functions on which the operation of our business may rely, which could negatively impact our business.
 The ability of the FDA, the EMA or comparable foreign regulatory authorities to review and approve products, including additional indications, can be affected by a variety of factors, including government budget and funding levels, ability to hire and retain key personnel and accept the payment of user fees, and enact statutory, regulatory and policy changes. Average review times at the FDA or other regulatory authorities have fluctuated in recent years as a result. Disruptions at the FDA and other agencies may also slow the time necessary for new product candidates to be reviewed and/or approved by necessary government agencies, which would adversely affect our business.
 In addition, government funding of the SEC and other government agencies on which our operations may rely, and those that fund research and development activities that is required by third parties we enter into agreements with, is subject to the political process, which is inherently fluid and unpredictable.
 Disruptions at the FDA, the EMA and other agencies may also slow the time necessary for new product candidates to be reviewed and/or approved by necessary government agencies, which would adversely affect our business. Currently, federal agencies in the U.S. are operating under a continuing resolution that is set to expire on September 30, 2025. In prior years the U.S. government has shut down several times and certain regulatory agencies, such as the FDA and the SEC, have had to furlough critical FDA, SEC and other government employees and stop critical activities. A prolonged government shutdown, significant leadership, personnel, and/or policy changes, or other substantial modification in agency activities (including due to global health concerns or geopolitical factors) could significantly impact the ability of the FDA to timely review and process our regulatory submissions, which could have a material adverse effect on our business.
 Further, in our operations as a public company, future government shutdowns could impact our ability to access the public markets and obtain necessary capital in order to properly capitalize and continue our operations.
 Patients receiving T cell-based immunotherapies such as Abecma may experience serious adverse events, including neurotoxicity and cytokine release syndrome. Serious adverse events or undesirable side effects associated with Abecma or our product candidates may result in delays, clinical holds, or terminations of our clinical trials, impact our ability to obtain or maintain marketing approval, and impact market acceptance and commercial sales, which will significantly harm our business, financial condition and prospects.

 Abecma is a CAR, T cell-based immunotherapy. In previous and ongoing clinical studies involving CAR T cell products, including those involving ide-cel, patients experienced side effects such as neurotoxicity and cytokine release syndrome. There have been life-threatening events related to severe neurotoxicity and cytokine release syndrome, requiring intense medical intervention such as intubation or vasopressor support, and in several cases, resulted in death. Severe neurotoxicity is a condition that is currently defined clinically by cerebral edema, confusion, drowsiness, speech impairment, tremors, seizures, or other central nervous system side effects, when such side effects are serious enough to lead to intensive care. In some cases, severe neurotoxicity was thought to be associated with the use of certain lymphodepletion regimens used prior to the administration of the CAR T cell products. Cytokine release syndrome is a condition that is currently defined clinically by certain symptoms related to the release of cytokines, which can include fever, chills, low blood pressure, when such side effects are serious enough to lead to intensive care with mechanical ventilation or significant vasopressor support. The exact cause or causes of cytokine release syndrome and severe neurotoxicity in connection with treatment of CAR T cell products is not fully understood at this time. In addition, patients have experienced other adverse events in these studies, such as a reduction in the number of blood cells (in the form of neutropenia, thrombocytopenia, anemia or other cytopenias), febrile neutropenia, chemical laboratory abnormalities (including elevated liver enzymes), and renal failure.
 Undesirable side effects caused by Abecma, other CAR T product candidates targeting BCMA, or our other engineered cell therapy product candidates, could cause us or regulatory authorities to interrupt, delay or halt clinical studies and could result in restrictions on the labeling, distribution, or marketing of our approved products or a requirement to conduct potentially costly post-approval studies or the delay or denial of marketing approval by the FDA or other comparable foreign regulatory authorities. For example, the prescribing information for Abecma includes a boxed warning for cytokine release syndrome, neurologic toxicities, and hemophagocytic lymphohistiocytosis/macrophage activation syndrome, and Abecma is only available in the U.S. through a REMS program. Additionally, the FDA has imposed a post-marketing requirement for Abecma that requires completion of an observational study to assess the long-term safety of Abecma and the risk of secondary malignancies occurring after treatment by following patients for a 15-year period. Further, in November 2023, the FDA announced that it would be conducting an investigation into reports of T cell malignancies following BCMA-directed or CD19-directed autologous CAR T cell immunotherapies following reports of T cell lymphoma in patients receiving these therapies. In January 2024, the FDA determined that new safety information related to T cell malignancies should be included in the labeling with boxed warning language on these malignancies for all BCMA- and CD-19-directed genetically modified autologous T cell immunotherapies, including Abecma. Side effects and toxicities associated with Abecma, as well as the warnings, precautions, and requirements listed in the prescribing information, could affect the willingness of physicians to prescribe, and patients to use, Abecma and negatively affect market acceptance and commercial sales. In some cases, side effects such as neurotoxicity or cytokine release syndrome have resulted in clinical holds of ongoing clinical trials and/or discontinuation of the development of the product candidate. Treatment-related side effects could also affect patient recruitment or the ability of enrolled patients to complete the studies or result in potential product liability claims. In addition, these side effects may not be appropriately recognized or managed by the treating medical staff, as toxicities resulting from engineered cell therapies are not normally encountered in the general patient population and by medical personnel. Medical personnel may need additional training regarding engineered cell therapies to understand their side effects. Inadequate training in recognizing or failure to effectively manage the potential side effects of engineered cell therapies could result in patient deaths. Any of these occurrences may harm our business, financial condition and prospects significantly.
 If we or others identify undesirable side effects caused by Abecma, a number of potentially significant negative consequences could result, including:
 • regulatory authorities may withdraw or limit their approval of Abecma;
 • regulatory authorities may require the addition of labeling statements, including a "boxed" warning or contraindications, such as the "boxed" warning included in the product label for Abecma;
 • we and/or BMS may be required to change the way Abecma is distributed or administered, conduct additional clinical trials or change the labeling for Abecma;

 • regulatory authorities may require a REMS plan to mitigate risks, such as the REMS program for Abecma;
 • we may be subject to regulatory investigations and government enforcement actions;
 • we or BMS may decide to remove Abecma from the marketplace;
 • we could be sued and held liable for injury caused to individuals exposed to or taking Abecma; and
 • our reputation may suffer.
 Negative public opinion and increased regulatory scrutiny of cell and gene therapy and genetic research may damage public perception of Abecma and any future products or adversely affect our ability to conduct our business or obtain and maintain marketing approvals for Abecma and our future product candidates.
 Public perception may be influenced by claims that cell and gene therapy, including gene editing technologies, is unsafe or unethical, and research activities and adverse events in the field, even if not ultimately attributable to us or Abecma or future product candidates, could result in increased governmental regulation, unfavorable public perception, challenges in recruiting patients to participate in our clinical studies, potential regulatory delays in the testing or approval of future product candidates, labeling restrictions for Abecma or any future approved products, and a decrease in demand for any such product. More restrictive government regulations or negative public opinion would have a negative effect on our business or financial condition and may delay or impair the development and commercialization of future product candidates or demand for any approved products.
 Changes in regulatory requirements, FDA guidance or unanticipated events during our preclinical studies and clinical studies of our product candidates may occur, which may result in changes to preclinical or clinical study protocols or additional preclinical or clinical study requirements, which could result in increased costs to us and could delay our development timeline.
 Changes in regulatory requirements, FDA guidance or unanticipated events during our preclinical studies and clinical studies may force us to amend preclinical studies and clinical study protocols. The FDA or comparable foreign regulatory authorities may also impose additional preclinical studies and clinical study requirements. Amendments or changes to our clinical study protocols would require resubmission to the FDA or comparable foreign regulatory authorities and IRBs for review and approval, which may increase the cost or delay the timing or successful completion of clinical studies. Similarly, amendments to our preclinical studies may increase the cost or delay the timing or successful completion of those preclinical studies. If we experience delays completing, or if we terminate, any of our preclinical or clinical studies, or if we are required to conduct additional preclinical or clinical studies, the commercial prospects for our product candidates may be harmed and our ability to recognize product revenue will be delayed.
 Obtaining and maintaining regulatory approval of Abecma in one jurisdiction does not mean that we will be successful in obtaining regulatory approval of our product candidates in other jurisdictions.
 In order to market any product outside of the United States, we must establish and comply with the numerous and varying safety, efficacy and other regulatory requirements of other countries. Obtaining and maintaining regulatory approval in one jurisdiction does not guarantee that we will be able to obtain or maintain regulatory approval in any other jurisdiction, but a failure or delay in obtaining regulatory approval in one jurisdiction may have a negative effect on the regulatory approval process in others. For example, even if the FDA or other comparable foreign regulatory authority grants marketing approval of a product candidate, comparable regulatory authorities in foreign jurisdictions must also approve the manufacturing, marketing and promotion of the product candidate in those countries. Approval procedures vary among jurisdictions and can involve requirements and administrative review periods different from those in the United States, including additional preclinical or clinical studies, as studies conducted in one jurisdiction may not be accepted by regulatory authorities in other jurisdictions. The marketing approval processes in other countries may implicate all of the risks detailed above regarding FDA approval in the United States, as well as other risks. In many jurisdictions outside the United States, a product candidate must be approved for reimbursement before it can be approved for sale in that jurisdiction. In some cases, the price that we intend to charge for our product candidates is also subject to approval.

 Obtaining foreign regulatory approvals and compliance with foreign regulatory requirements could result in significant delays, difficulties and costs for us and could delay or prevent the introduction of our products in certain countries. Failure to obtain marketing approval in other countries or any delay or other setback in obtaining such approval would impair our ability to market our product candidates in such countries. Any such impairment would reduce the size of our potential market, which could have a material adverse impact on our business, prospects, financial condition and results of operations.
 Risks Related to Our Reliance on Third Parties
 We are dependent on BMS for the successful development, commercialization and manufacture of Abecma. If BMS does not devote sufficient resources to the commercialization, manufacture and further development of Abecma, is unsuccessful in its efforts, or chooses to terminate its agreements with us, our business will be materially harmed.
 We are partnering with BMS to develop and promote ide-cel, being marketed as Abecma in the United States, under the Ide-cel CCPS.
 In our partnership with BMS, BMS is obligated to use commercially reasonable efforts to develop and commercialize ide-cel. BMS may determine however, that it is commercially reasonable to de-prioritize or discontinue the development of ide-cel. These decisions may occur for many reasons, including internal business reasons (including due to the existence of other BMS programs that are potentially competitive with ide-cel), results from clinical trials or because of unfavorable regulatory feedback. Further, on review of the safety and efficacy data, the FDA may impose additional requirements on the program that renders it commercially nonviable. In addition, under our agreements with BMS, BMS has certain decision-making rights in determining the development and commercialization plans and activities. We may disagree with BMS about the development strategy it employs, but we will have limited rights to impose our development strategy on BMS. Similarly, BMS may decide to seek marketing approval for, and limit commercialization of, ide-cel to narrower indications than we would pursue. More broadly, if BMS elects to discontinue further development and commercialization of ide-cel, we may be unable to advance these efforts ourselves. In addition, we rely on BMS to deliver complete, accurate and timely information about its financial results related to ide-cel.
 This partnership may not be scientifically or commercially successful for us due to a number of important factors, including the following:
 • BMS has wide discretion in determining the efforts and resources that it will apply to its partnership with us. The timing and amount of any downstream commercial profits, milestones and royalties that we may receive under such partnership will depend on, among other things, BMS's efforts, allocation of resources and successful development and commercialization of ide-cel.
 • BMS may develop and commercialize, either alone or with others, products that are similar to or competitive with ide-cel. For example, BMS is currently commercializing a number of its existing products, including lenalidomide and pomalidomide, for certain patients with relapsed and refractory multiple myeloma, as well as our CAR-T product candidate targeting BCMA.
 • BMS may terminate its partnership with us without cause and for circumstances outside of our control, which could make it difficult for us to attract new strategic partners or adversely affect how we are perceived in scientific and financial communities.
 • BMS may develop or commercialize Abecma in such a way as to elicit litigation that could jeopardize or invalidate our intellectual property rights or expose us to potential liability.
 • BMS may not comply with all applicable regulatory and compliance requirements, including failing to report safety data in accordance with all applicable regulatory requirements.
 • If BMS were to breach its arrangements with us, we may need to enforce our right to terminate the agreement in legal proceedings, which could be costly and cause delay in our ability to receive Abecma

 rights back. If we were to terminate an agreement with BMS due to BMS's breach or if BMS were to terminate an agreement without cause, the development and commercialization of Abecma could be delayed, curtailed or terminated because we may not have sufficient financial resources or capabilities to continue development and commercialization of these product candidates on our own if we choose not to, or are unable to, enter into a new collaboration for these product candidates.
 • BMS may enter into one or more transactions with third parties, including a merger, consolidation, reorganization, sale of substantial assets, sale of substantial stock or other change in control, which could divert the attention of its management and adversely affect BMS's ability to retain and motivate key personnel who are important to the continued development of Abecma. In addition, the third-party to any such transaction could determine to re-prioritize BMS's development programs such that BMS ceases to diligently pursue the development of Abecma and/or cause the respective collaboration with us to terminate.
 We rely on third parties to conduct, supervise and monitor our clinical studies, and if these third parties perform in an unsatisfactory manner, it may harm our business.
 We rely on CROs and clinical study sites to ensure our studies are conducted properly and on time. While we have agreements governing their activities, we will have limited influence over their actual performance. We control only certain aspects of our CROs' activities, and as a result, we have less direct control over the conduct, timing, and completion of our clinical studies and the management of data developed through studies than would be the case if we relied on our own staff. Nevertheless, we are responsible for ensuring that each of our clinical studies is conducted in accordance with the applicable protocol, legal, regulatory and scientific standards, and our reliance on the CROs does not relieve us of our regulatory responsibilities.
 We and our CROs are required to comply with the FDA's and other regulatory authorities' GCPs for conducting, recording and reporting the results of clinical studies to assure that the data and reported results are credible and accurate and that the rights, integrity and confidentiality of clinical study participants are protected. Regulatory authorities enforce these GCPs through periodic inspections of trial sponsors, principal investigators, and trial sites. If we or our CROs fail to comply with applicable GCPs, the clinical data generated in our future clinical studies may be deemed unreliable and the FDA and other regulatory authorities may require us to perform additional clinical studies before approving any marketing applications.
 If our CROs do not successfully carry out their contractual duties or obligations, fail to meet expected deadlines, or if the quality or accuracy of the clinical data they obtain is compromised due to the failure to adhere to our clinical protocols or regulatory requirements, or for any other reasons, our clinical studies may be extended, delayed or terminated, and we may not be able to obtain marketing approval for, or successfully commercialize our product candidates. As a result, our financial results and the commercial prospects for our product candidates would be harmed, our costs could increase, and our ability to recognize revenues could be delayed.
 We rely on third parties to conduct some or all aspects of our lentiviral vector production, drug product manufacturing, and testing, and these third parties may not perform satisfactorily.
 We do not independently conduct all aspects of our lentiviral vector production, drug product manufacturing, and testing. We currently rely, and expect to continue to rely, on third parties with respect to these items, including manufacturing and testing in the preclinical, clinical and commercial context.
 Our reliance on these third parties for manufacturing, testing, research and development activities reduce our control over these activities but will not relieve us of our responsibility to ensure compliance with all required regulations and study protocols. For example, for products that we develop and commercialize on our own, we will remain responsible for ensuring that each of our IND-enabling studies and clinical studies are conducted in accordance with the study plan and protocols, and that our lentiviral vectors and drug products are manufactured in accordance with GMP as applied in the relevant jurisdictions. Our third-party manufacturers are subject to inspections by the FDA and comparable foreign regulatory authorities to confirm compliance with applicable regulatory requirements.

 If these third parties do not successfully carry out their contractual duties, meet expected deadlines, conduct our studies in accordance with regulatory requirements or our stated study plans and protocols, or manufacture our lentiviral vectors and drug products in accordance with GMP, we will not be able to complete, or may be delayed in completing, the preclinical and clinical studies and manufacturing process validation activities required to support future IND, marketing authorization application, or MAA, and BLA submissions and approval of our product candidates, or to support commercialization of Abecma or any future products. Many of our agreements with these third parties contain termination provisions that allow these third parties to terminate their relationships with us at any time. If we need to enter into alternative arrangements, our product development and commercialization activities could be delayed.
 Reliance on third-party manufacturers entails risks to which we would not be subject if we manufactured the products ourselves, including:
 • the inability to negotiate manufacturing agreements with third parties under commercially reasonable terms;
 • reduced control as a result of using third-party manufacturers for all aspects of manufacturing activities;
 • the risk that these activities are not conducted in accordance with our study plans and protocols;
 • termination or nonrenewal of manufacturing agreements with third parties in a manner or at a time that is costly or damaging to us; and
 • disruptions to the operations of our third-party manufacturers or suppliers caused by conditions unrelated to our business or operations, including the bankruptcy of the manufacturer or supplier.
 We may be forced to enter into an agreement with a different manufacturer, which we may not be able to do on reasonable terms or without delays, if at all. In some cases, the technical skills required to manufacture our lentiviral vector or drug product candidates may be unique or proprietary to the original manufacturer, and we may have difficulty or there may be contractual restrictions prohibiting us from, transferring such skills to a back-up or alternate supplier, or we may be unable to transfer such skills at all. Any of these events could lead to clinical study delays or failure to obtain marketing approval, or impact our ability to successfully commercialize Abecma or any future products. Some of these events could be the basis for FDA or comparable foreign regulatory action, including injunction, recall, seizure or total or partial suspension of production. In addition, if we are required to change third-party manufacturers for any reason, we will be required to verify that the new manufacturer maintains facilities and procedures that comply with quality standards and with all applicable regulations.
 We also may alter various aspects of Abecma, such as the manufacturing, formulation, method of administration or other alterations designed to optimize the candidate or processes for scale necessary for later stage clinical trials and potential approval and commercialization. For example, we intend to switch to a suspension vector for Abecma. These changes may not produce the intended optimization, including production of drug substance and drug product of a quality and in a quantity sufficient for further clinical development or commercialization, which may cause delays in the initiation or completion of clinical trials or impact commercialization and result in greater costs. We will need to verify, such as through a manufacturing comparability study, that any new manufacturing process, by us or by a new manufacturer, will produce Abecma according to the specifications previously submitted to the FDA or another comparable foreign regulatory authority.
 The delays associated with the verification of a new third-party manufacturer or new manufacturing process could negatively affect our ability to develop product candidates or commercialize any approved products in a timely manner or within budget. In addition, changes in manufacturers often involve changes in manufacturing procedures and processes, which could require that we conduct bridging studies between our prior clinical supply used in our clinical trials and that of any new manufacturer. We may be unsuccessful in demonstrating the comparability of clinical supplies which could require the conduct of additional clinical trials.

 We and our contract manufacturers are subject to significant regulation with respect to manufacturing Abecma. The manufacturing facilities on which we rely may not continue to meet regulatory requirements and have limited capacity.
 All entities involved in the preparation of therapeutics for clinical studies or commercial sale, including existing contract manufacturers for Abecma, are subject to extensive regulation. Abecma in clinical studies must be manufactured in accordance with GMP. These regulations govern manufacturing processes and procedures (including record keeping) and the implementation and operation of quality systems to control and assure the quality of investigational products and products approved for sale. Poor control of production processes can lead to the introduction of adventitious agents or other contaminants, or to inadvertent changes in the properties or stability of Abecma that may not be detectable in final product testing. We or our contract manufacturers must supply all necessary documentation in support of a BLA or MAA on a timely basis and where required, must adhere to GLP and GMP regulations enforced by the FDA or other regulators through facilities inspection programs. Some of our contract manufacturers have not produced a commercially-approved product and therefore have not obtained the requisite FDA or other marketing approvals to do so. Our facilities and quality systems and the facilities and quality systems of some or all of our third-party contractors must pass a pre-approval inspection for compliance with the applicable regulations as a condition of marketing approval for our product candidates. In addition, the regulatory authorities may, at any time, audit or inspect a manufacturing facility involved with the preparation of our product candidates or the associated quality systems for compliance with the regulations applicable to the activities being conducted. If these facilities do not pass a pre-approval plant inspection, FDA or other marketing approval of the products will not be granted.
 The regulatory authorities also may, at any time following approval of a product for sale, audit the manufacturing facilities of our third-party contractors. If any such inspection or audit identifies a failure to comply with applicable regulations or if a violation of our product specifications or applicable regulations occurs independent of such an inspection or audit, we or the relevant regulatory authority may require remedial measures that may be costly and/or time-consuming for us or a third party to implement and that may include the temporary or permanent suspension of a clinical study or commercial sales or the temporary or permanent closure of a facility. Any such remedial measures imposed upon us or third parties with whom we contract could materially harm our business.
 If we or any of our third-party manufacturers fail to maintain regulatory compliance, the FDA or other regulators can impose regulatory sanctions including, among other things, refusal to approve a pending application for a biologic product, or revocation of or restrictions to an approved BLA. As a result, our business, financial condition and results of operations may be materially harmed.
 The manufacturing processes for our lentiviral vectors and our drug products are complex. We explore improvements to our manufacturing processes on a regular basis, as we evaluate clinical and manufacturing data and based on discussions with regulatory authorities. In some circumstances, changes in the manufacturing process, such as our planned switch to a suspension vector for Abecma, may require us to perform additional comparability studies, develop additional assays, modify release specifications, collect additional data from patients, submit additional regulatory filings, or comply with additional requirements, which may lead to delays in our clinical development and commercialization plans. Additionally, the FDA may not agree with our changes to the manufacturing process which could require us to perform additional development work and lead to further delays.
 If supply from one approved manufacturer is interrupted, there could be a significant disruption in commercial supply. The number of manufacturers with the necessary manufacturing capabilities is limited. In addition, an alternative manufacturer would need to be qualified through a BLA supplement or similar regulatory submission which could result in further delay. The regulatory agencies may also require additional studies if a new manufacturer is relied upon for commercial production. Switching manufacturers may involve substantial costs and is likely to result in a delay in our desired clinical and commercial timelines.
 These factors could cause the delay of clinical studies, regulatory submissions, required approvals or commercialization of Abecma and any future products, cause us to incur higher costs and prevent us from commercializing our products successfully. Furthermore, if our suppliers fail to meet contractual requirements, and

 we are unable to secure one or more replacement suppliers capable of production at a substantially equivalent cost, our clinical studies may be delayed, our commercial activities may be impacted, or we could lose potential revenues.
 Our reliance on third parties requires us to share our trade secrets, which increases the possibility that a competitor will discover them or that our trade secrets will be misappropriated or disclosed.
 Because we rely on third parties to manufacture our vectors and our drug products, and because we collaborate with various organizations and academic institutions on the advancement of our engineered cell therapy technologies, we must, at times, share trade secrets with them. We seek to protect our proprietary technology in part by entering into confidentiality agreements and, if applicable, material transfer agreements, collaborative research agreements, consulting agreements or other similar agreements with our collaborators, advisors, employees and consultants prior to beginning research or disclosing proprietary information. These agreements typically limit the rights of the third parties to use or disclose our confidential information, such as trade secrets. Despite the contractual provisions employed when working with third parties, the need to share trade secrets and other confidential information increases the risk that such trade secrets become known by our competitors, are inadvertently incorporated into the technology of others, or are disclosed or used in violation of these agreements. Given that our proprietary position is based, in part, on our know-how and trade secrets, a competitor's discovery of our trade secrets or other unauthorized use or disclosure would impair our competitive position and may have a material adverse effect on our business.
 In addition, these agreements typically restrict the ability of our collaborators, advisors, employees and consultants to publish data potentially relating to our trade secrets. Our academic collaborators typically have rights to publish data, provided that we are notified in advance and may delay publication for a specified time in order to secure our intellectual property rights arising from the collaboration. In other cases, publication rights are controlled exclusively by us, although in some cases we may share these rights with other parties. We also conduct joint research and development programs that may require us to share trade secrets under the terms of our research and development partnerships or similar agreements. Despite our efforts to protect our trade secrets, our competitors may discover our trade secrets, either through breach of these agreements, independent development or publication of information including our trade secrets in cases where we do not have proprietary or otherwise protected rights at the time of publication. A competitor's discovery of our trade secrets would impair our competitive position and have an adverse impact on our business.
 Any collaboration or license arrangements that we may enter into in the future may not be successful, which could impede our ability to develop and commercialize our product candidates.
 We may seek collaboration or license arrangements for the commercialization, or potentially for the development, of certain of any potential future product candidates depending on the merits of retaining commercialization rights for ourselves as compared to entering into collaboration or license arrangements. We will face, to the extent that we decide to enter into such arrangements, significant competition in seeking appropriate partners. Moreover, collaboration and license arrangements are complex and time-consuming to negotiate, document, implement and maintain. We may not be successful in our efforts to establish and implement such arrangements should we so chose to enter into them. The terms of any collaborations, licenses or other arrangements that we may establish may not be favorable to us.
 Any future collaboration or license arrangements that we enter into may not be successful. The success of such arrangements will depend heavily on the efforts and activities of our partners. Collaboration and license arrangements are subject to numerous risks, which may include risks that:
 • partners have significant discretion in determining the efforts and resources that they will apply to collaborations;
 • a partner with marketing, manufacturing and distribution rights to one or more products may not commit sufficient resources to or otherwise not perform satisfactorily in carrying out these activities;
 • partners may not properly maintain or defend our intellectual property rights or may use our intellectual property or proprietary information in a way that gives rise to actual or threatened litigation that could

 jeopardize or invalidate our intellectual property or proprietary information or expose us to potential liability;
 • collaboration and license arrangements may be terminated, and, if terminated, this may result in a need for additional capital to pursue further development or commercialization of the applicable future product candidates;
 • partners may own or co-own intellectual property covering products that results from our collaborating with them, and in such cases, we would not have the exclusive right to develop or commercialize such intellectual property;
 • disputes may arise with respect to the ownership of any intellectual property developed pursuant to our collaboration or license arrangements; and
 • a partner's sales and marketing activities or other operations may not be in compliance with applicable laws resulting in civil or criminal proceedings.
 Risks Related to Our Intellectual Property Rights
 If we are unable to obtain or protect intellectual property rights related to our approved product, we may not be able to compete effectively in our markets.
 We rely upon a combination of patents, trade secret protection and confidentiality agreements to protect the intellectual property related to our approved product. The strength of patents in the biotechnology and pharmaceutical field involves complex legal and scientific questions and can be uncertain. The patent applications that we own or in-license may fail to result in issued patents with claims that cover our approved product in the United States or in other foreign countries. There is no assurance that all of the potentially relevant prior art relating to our patents and patent applications has been found, which can invalidate a patent or prevent a patent from issuing from a pending patent application. Even if patents do successfully issue and even if such patents cover our approved product or product candidates, third parties have and may challenge their validity, enforceability or scope, which may result in such patents being narrowed or invalidated. Furthermore, even if they are unchallenged, our patents and patent applications may not adequately protect our intellectual property, provide exclusivity for our approved product or product candidates or prevent others from designing around our claims. Any of these outcomes could impair our ability to prevent competition from third parties, which may have an adverse impact on our business.
 If the patent applications we hold or have in-licensed with respect to our programs or approved product or product candidates fail to issue, if their breadth or strength of protection is threatened, or if they fail to provide meaningful exclusivity for our approved product or product candidates, it could dissuade companies from collaborating with us to develop product candidates, and threaten our ability to commercialize, future products. Several patent applications covering our product candidates have been filed recently. We cannot offer any assurances about which, if any, patents will issue, the breadth of any such patent or whether any issued patents will be found invalid and unenforceable or will be threatened by third parties. Any successful opposition to these patents or any other patents owned by or licensed to us could deprive us of rights necessary for the successful commercialization of our approved product or any product candidates that we may develop. Further, if we encounter delays in regulatory approvals, the period of time during which we could market a product candidate under patent protection could be reduced. Since patent applications in the United States and most other countries are confidential for a period of time after filing, and some remain so until issued, we cannot be certain that we were the first to file any patent application related to a product candidate or our approved product. Furthermore, if third parties have filed such patent applications, an interference or derivation proceeding in the United States can be initiated by a third-party to determine who was the first to invent any of the subject matter covered by the patent claims of our applications. In addition, patents have a limited lifespan. In the United States, the natural expiration of a patent is generally 20 years after it is filed. Various extensions may be available however the life of a patent, and the protection it affords, is limited. Even if patents covering our approved product or product candidates are obtained, once the patent life has expired for a product, we may be open to competition from generic medications.

 In addition to the protection afforded by patents, we rely on trade secret protection and confidentiality agreements to protect proprietary know-how that is not patentable or that we elect not to patent, processes for which patents are difficult to enforce and any other elements of our approved product or product candidate discovery and development processes that involve proprietary know-how, and information or technology that is not covered by patents. However, trade secrets can be difficult to protect. We seek to protect our proprietary technology and processes, in part, by entering into confidentiality agreements with our employees, consultants, scientific advisors and contractors. We also seek to preserve the integrity and confidentiality of our data and trade secrets by maintaining physical security of our premises and physical and electronic security of our information technology systems. While we have confidence in these individuals, organizations and systems, agreements or security measures may be breached, and we may not have adequate remedies for any breach. In addition, our trade secrets may otherwise become known or be independently discovered by competitors.
 Although we expect all of our employees and consultants to assign their inventions to us, and all of our employees, consultants, advisors and any third parties who have access to our proprietary know-how, information or technology to enter into confidentiality agreements, we cannot provide any assurances that all such agreements have been duly executed or that our trade secrets and other confidential proprietary information will not be disclosed or that competitors will not otherwise gain access to our trade secrets or independently develop substantially equivalent information and techniques. Misappropriation or unauthorized disclosure of our trade secrets could impair our competitive position and may have a material adverse effect on our business. Additionally, if the steps taken to maintain our trade secrets are deemed inadequate, we may have insufficient recourse against third parties for misappropriating the trade secret. In addition, others may independently discover our trade secrets and proprietary information. For example, the FDA, as part of its transparency initiative, may consider whether to make additional information publicly available on a routine basis, including information that we may consider to be trade secrets or other proprietary information, and it is not clear at the present time how the FDA's disclosure policies may change in the future, if at all.
 Further, the laws of some foreign countries do not protect proprietary rights to the same extent or in the same manner as the laws of the United States. As a result, we may encounter significant problems in protecting and defending our intellectual property both in the United States and abroad. If we are unable to prevent material disclosure of the non-patented intellectual property related to our technologies to third parties, and there is no guarantee that we will have any such enforceable trade secret protection, we may not be able to establish or maintain a competitive advantage in our market, which could materially adversely affect our business, results of operations and financial condition.
 Third-party claims of intellectual property infringement may prevent or delay our development and commercialization efforts.
 Our commercial success depends in part on our avoiding infringement of the patents and proprietary rights of third parties. There is a substantial amount of litigation, both within and outside the United States, involving patent and other intellectual property rights in the biotechnology and pharmaceutical industries, including patent infringement lawsuits, interferences, derivation proceedings, oppositions, ex parte reexaminations, post-grant review, and inter partes review proceedings before the federal courts or the U.S. Patent and Trademark Office, or U.S. PTO, and corresponding foreign courts and patent offices. Numerous U.S. and foreign issued patents and pending patent applications, which are owned by third parties, exist in the fields in which we have an approved product or are pursuing development candidates. As the biotechnology and pharmaceutical industries expand and more patents are issued, the risk increases that our approved product or product candidates may be subject to claims of infringement of the patent rights of third parties.
 Third parties may assert that we are employing their proprietary technology without authorization. There may be third-party patents or patent applications with claims to materials, formulations, methods of manufacture or methods for treatment related to the use or manufacture of our approved product or product candidates. Because patent applications can take many years to issue, there may be currently pending patent applications which may later result in issued patents that our approved product or product candidates may infringe. In addition, third parties may obtain patents in the future and claim that use of our technologies infringes upon these patents. If any third-party patents were held by a court of competent jurisdiction to cover the manufacturing process of any of our approved

 product or product candidates, any molecules formed during the manufacturing process or any final product itself, the holders of any such patents may be able to block our ability to commercialize such product candidate unless we obtained a license under the applicable patents, or until such patents expire. Similarly, if any third-party patents were held by a court of competent jurisdiction to cover aspects of our formulations, processes for manufacture or methods of use, including combination therapy, the holders of any such patents may be able to block our ability to develop and commercialize our approved product or the applicable product candidate unless we obtained a license or until such patent expires. In either case, such a license may not be available on commercially reasonable terms or at all.
 Parties making claims against us may obtain injunctive or other equitable relief, which could effectively block our ability to further develop and commercialize one or more of our product candidates. Defense of these claims, regardless of their merit, would involve substantial litigation expense and would be a substantial diversion of employee resources from our business. In the event of a successful claim of infringement against us, we may have to pay substantial damages, including treble damages and attorneys' fees for willful infringement, pay royalties, redesign our infringing products or obtain one or more licenses from third parties, which may be impossible or require substantial time and monetary expenditure.
 We may not be successful in obtaining or maintaining necessary rights to cell and gene therapy product components and processes for our approved product or development pipeline through acquisitions and in-licenses.
 Presently we have rights to the intellectual property, through licenses from third parties or sublicenses from bluebird bio and under patents that we own, to develop our product candidates and commercialize our approved product. Because our programs may involve additional product candidates that may require the use of proprietary rights held by third parties, the growth of our business will likely depend in part on our ability to acquire, in-license or use these proprietary rights. In addition, our product candidates may require specific formulations to work effectively and efficiently and these rights may be held by others. We may be unable to acquire or in-license, either through direct license or sublicenses, any compositions, methods of use, processes or other third-party intellectual property rights from third parties that we identify. The licensing and acquisition of third-party intellectual property rights is a competitive area, and a number of more established companies are also pursuing strategies to license or acquire third-party intellectual property rights that we may consider attractive. These established companies may have a competitive advantage over us due to their size, cash resources and greater clinical development and commercialization capabilities.
 For example, we sometimes collaborate with U.S. and foreign academic institutions to accelerate our preclinical research or development under written agreements with these institutions. Typically, these institutions provide us with an option to negotiate a license to any of the institution's rights in technology resulting from the collaboration. Regardless of such right of first negotiation for intellectual property, we may be unable to negotiate a license within the specified time frame or under terms that are acceptable to us. If we are unable to do so, the institution may offer the intellectual property rights to other parties, potentially blocking our ability to pursue our program.
 In addition, companies that perceive us to be a competitor may be unwilling to assign or license rights to us. We also may be unable to license or acquire third-party intellectual property rights on terms that would allow us to make an appropriate return on our investment. If we are unable to successfully obtain rights to required third-party intellectual property rights, our business, financial condition and prospects for growth could suffer.
 If we fail to comply with our obligations in the agreements under which we license intellectual property rights from third parties or otherwise experience disruptions to our business relationships with our licensors, we could lose license rights that are important to our business.
 We are a party to a number of intellectual property license agreements that are important to our business and expect to enter into additional license agreements in the future. Our existing license agreements impose, and we expect that future license agreements will impose, various diligence, milestone payment, royalty and other obligations on us. If we fail to comply with our obligations under these agreements, or we are subject to a bankruptcy, the licensor may have the right to terminate the license, in which event we would not be able to market products covered by the license.

 Where we are a sublicensee of certain intellectual property rights from a third party, our sublicensed rights may be terminated due to defaults of our licensor, or for any other reasons, under the original license agreement between our licensor and the third party. In such a scenario, we may be unable to negotiate a license directly with the third party under terms that are acceptable to us, and as a result, our ability to develop and commercialize our products or product candidates may be impaired.
 We may need to obtain licenses from third parties to advance the development of our product candidates or allow commercialization of our approved product, and we have done so from time to time. We may fail to obtain any of these licenses at a reasonable cost or on reasonable terms, if at all. In that event, we may be required to expend significant time and resources to develop or license replacement technology. If we are unable to do so, we may be unable to develop or commercialize the affected future product candidates or approved product, which could harm our business significantly. We cannot provide any assurances that third-party patents do not exist which might be enforced against our approved product, or future products, resulting in either an injunction prohibiting our sales, or, with respect to our sales, an obligation on our part to pay royalties and/or other forms of compensation to third parties.
 In many cases, patent prosecution of our licensed technology is controlled solely by the licensor. If our licensors fail to obtain and maintain patent or other protection for the proprietary intellectual property we license from them, we could lose our rights to the intellectual property or our exclusivity with respect to those rights, and our competitors could market competing products using the intellectual property. In certain cases, we control the prosecution of patents resulting from licensed technology. In the event we breach any of our obligations related to such prosecution, we may incur significant liability to our licensing partners. Licensing of intellectual property is of critical importance to our business and involves complex legal, business, and scientific issues and is complicated by the rapid pace of scientific discovery in our industry. Disputes may arise regarding intellectual property subject to a licensing agreement, including:
 • the scope of rights granted under the license agreement and other interpretation-related issues;
 • the extent to which our technology and processes infringe on intellectual property of the licensor that is not subject to the licensing agreement;
 • the sublicensing of patent and other rights under our collaborative development relationships;
 • our diligence obligations under the license agreement and what activities satisfy those diligence obligations;
 • the ownership of inventions and know-how resulting from the joint creation or use of intellectual property by our licensors and us and our partners; and
 • the priority of invention of patented technology.
 If disputes over intellectual property that we have licensed prevent or impair our ability to maintain our current licensing arrangements on acceptable terms, we may be unable to successfully develop and commercialize the affected approved product or product candidates.
 We may be involved in lawsuits to protect or enforce our patents or the patents of our licensors, which could be expensive, time-consuming and unsuccessful.
 Competitors may infringe our patents or the patents of our licensors. To counter infringement or unauthorized use, we may be required to file infringement claims, which can be expensive and time-consuming. In addition, in an infringement proceeding, a court may decide that a patent of ours or our licensors is not valid, is unenforceable and/or is not infringed, or may refuse to stop the other party from using the technology at issue on the grounds that our patents do not cover the technology in question. In patent litigation in the United States, defendant counterclaims alleging invalidity and/or unenforceability are commonplace. Grounds for a validity challenge could be an alleged failure to meet any of several statutory requirements, including patent eligible subject matter, lack of novelty, obviousness or non-enablement. Grounds for an unenforceability assertion could be an allegation that someone connected with prosecution of the patent withheld relevant information from the U.S. PTO, or made a misleading

 statement, during prosecution. Third parties have and may raise similar claims before administrative bodies in the United States or abroad, even outside the context of litigation. Such mechanisms include re-examination, post grant review, and equivalent proceedings in foreign jurisdictions (e.g., opposition proceedings). Such proceedings could result in revocation or amendment to our patents in such a way that they no longer cover our product candidates. The outcome following legal assertions of invalidity and unenforceability is unpredictable. With respect to the validity challenges, for example, we cannot be certain that there is no invalidating prior art, of which we and the patent examiner were unaware during prosecution. If a defendant were to prevail on a legal assertion of invalidity and/or unenforceability, we would lose at least part, and perhaps all, of the patent protection on our approved product and/or product candidates. Such a loss of patent protection would have a material adverse impact on our business.
 Interference or derivation proceedings provoked by third parties or brought by us may be necessary to determine the priority of inventions with respect to our patents or patent applications or those of our licensors. An unfavorable outcome could require us to cease using the related technology or to attempt to license rights to it from the prevailing party. Our business could be harmed if the prevailing party does not offer us a license on commercially reasonable terms. Our defense of litigation or interference or derivation proceedings may fail and, even if successful, may result in substantial costs and distract our management and other employees. We may not be able to prevent, alone or with our licensors, misappropriation of our intellectual property rights, particularly in countries where the laws may not protect those rights as fully as in the United States.
 Furthermore, because of the substantial amount of discovery required in connection with intellectual property litigation, there is a risk that some of our confidential information could be compromised by disclosure during this type of litigation. There could also be public announcements of the results of hearings, motions or other interim proceedings or developments. If securities analysts or investors perceive these results to be negative, it could have a material adverse effect on the price of our common stock.
 We may be subject to claims that our employees, consultants, or independent contractors have wrongfully used or disclosed confidential information of third parties or that our employees have wrongfully used or disclosed alleged trade secrets of their former employers.
 We employ individuals who were previously employed at universities or other biotechnology or pharmaceutical companies, including our competitors or potential competitors. Although we try to ensure that our employees, consultants and independent contractors do not use the proprietary information or know-how of others in their work for us, we may be subject to claims that we or our employees, consultants, or independent contractors have inadvertently or otherwise used or disclosed intellectual property, including trade secrets or other proprietary information, of any of our employee's former employer or other third parties. Litigation may be necessary to defend against these claims. If we fail in defending any such claims, in addition to paying monetary damages, we may lose valuable intellectual property rights or personnel, which could adversely impact our business. Even if we are successful in defending against such claims, litigation could result in substantial costs and be a distraction to management and other employees.
 We may be subject to claims challenging the inventorship or ownership of our patents and other intellectual property.
 We may also be subject to claims that former employees, collaborators or other third parties have an ownership interest in our patents or other intellectual property. We have had in the past, and we may also have in the future, ownership disputes arising, for example, from conflicting obligations of consultants or others who are involved in developing our approved product or product candidates. Litigation may be necessary to defend against these and other claims challenging inventorship or ownership. If we fail in defending any such claims, in addition to paying monetary damages, we may lose valuable intellectual property rights, such as exclusive ownership of, or right to use, valuable intellectual property. Such an outcome could have a material adverse effect on our business. Even if we are successful in defending against such claims, litigation could result in substantial costs and be a distraction to management and other employees.
 Obtaining and maintaining our patent protection depends on compliance with various procedural, document submission, fee payment and other requirements imposed by governmental patent agencies, and our patent protection could be reduced or eliminated for non-compliance with these requirements.

 Periodic maintenance fees, renewal fees, annuity fees, and various other governmental fees on patents and/or applications will be due to be paid to the U.S. PTO and various governmental patent agencies outside of the United States in several stages over the lifetime of the patents and/or applications. We have systems in place to remind us to pay these fees, and we employ an outside firm and rely on our outside counsel to pay these fees due to non-U.S. patent agencies. The U.S. PTO and various non-U.S. governmental patent agencies require compliance with a number of procedural, documentary, fee payment and other similar provisions during the patent application process. We employ reputable law firms and other professionals to help us comply, and in many cases, an inadvertent lapse can be cured by payment of a late fee or by other means in accordance with the applicable rules. However, there are situations in which non-compliance can result in abandonment or lapse of the patent or patent application, resulting in partial or complete loss of patent rights in the relevant jurisdiction. In such an event, our competitors might be able to enter the market and this circumstance would have a material adverse effect on our business.
 Changes in U.S. patent law could diminish the value of patents in general, thereby impairing our ability to protect our products.
 As is the case with other biotechnology companies, our success is heavily dependent on intellectual property, particularly patents. Obtaining and enforcing patents in the biotechnology industry involve both technological and legal complexity, and is therefore costly, time-consuming and inherently uncertain. In addition, the United States has recently enacted and is currently implementing wide-ranging patent reform legislation. Recent U.S. Supreme Court rulings have narrowed the scope of patent protection available in certain circumstances and weakened the rights of patent owners in certain situations. In addition to increasing uncertainty with regard to our ability to obtain patents in the future, this combination of events has created uncertainty with respect to the value of patents, once obtained. Depending on decisions by the U.S. Congress, the federal courts, and the U.S. PTO, the laws and regulations governing patents could change in unpredictable ways that would weaken our ability to obtain new patents or to enforce our existing patents and patents that we might obtain in the future.
 We may not be able to protect our intellectual property rights throughout the world.
 Filing, prosecuting and defending patents on product candidates in all countries throughout the world would be prohibitively expensive, and our intellectual property rights in some countries outside the United States can be less extensive than those in the United States. In addition, the laws of some foreign countries do not protect intellectual property rights to the same extent as federal and state laws in the United States. Consequently, we may not be able to prevent third parties from practicing our inventions in all countries outside the United States, or from selling or importing products made using our inventions in and into the United States or other jurisdictions. Competitors may use our technologies in jurisdictions where we have not obtained patent protection to develop their own products and further, may export otherwise infringing products to territories where we have patent protection, but enforcement is not as strong as that in the United States. These products may compete with our products and our patents or other intellectual property rights may not be effective or sufficient to prevent them from competing.
 Many companies have encountered significant problems in protecting and defending intellectual property rights in foreign jurisdictions. The legal systems of certain countries, particularly certain developing countries, do not favor the enforcement of patents, trade secrets and other intellectual property protection, particularly those relating to biotechnology products, which could make it difficult for us to stop the infringement of our patents or marketing of competing products in violation of our proprietary rights generally. Proceedings to enforce our patent rights in foreign jurisdictions could result in substantial costs and divert our efforts and attention from other aspects of our business, could put our patents at risk of being invalidated or interpreted narrowly and our patent applications at risk of not issuing and could provoke third parties to assert claims against us. We may not prevail in any lawsuits that we initiate and the damages or other remedies awarded, if any, may not be commercially meaningful. Accordingly, our efforts to enforce our intellectual property rights around the world may be inadequate to obtain a significant commercial advantage from the intellectual property that we develop or license.
 Risks Related to the Commercialization of Our Product Candidates
 We have limited experience as a commercial company and the marketing and sale of Abecma or any future approved products may be unsuccessful or less successful than anticipated.

 Although BMS has responsibility for, and is undertaking, the key commercialization activities for Abecma, to the extent we are required to participate in commercialization activities we have limited experience in doing so, and we may not be able to successfully overcome many of the risks and uncertainties encountered by companies commercializing products in the biopharmaceutical industry. To execute our business plan, in addition to successfully marketing and selling any future products for which we gain regulatory approval, we will need to successfully:
 • establish and maintain our relationships with healthcare providers who will be treating the patients who may receive Abecma;
 • obtain adequate pricing and reimbursement for any future products, if approved;
 • develop and maintain successful strategic alliances; and
 • manage our spending as costs and expenses increase due to clinical trials, marketing approvals, and commercialization.
 If we are unsuccessful in accomplishing these objectives, we may not be able to successfully develop and commercialize Abecma or any future products, if approved, raise capital or continue our operations.
 We may not be successful in supporting the commercialization of Abecma.
 BMS is primarily responsible for the commercialization of Abecma, and there can be no guarantee that BMS will be able to commercialize Abecma successfully. Although we have recognized collaborative arrangement revenue related to commercial sales of Abecma, we cannot be certain that we will continue to generate such revenue. The extent to which we will recognize revenue from Abecma depends on a number of factors, including, but not limited to, BMS' ability to:
 • set an acceptable price for Abecma;
 • obtain commercial quantities of Abecma, at acceptable cost levels;
 • establish and maintain a commercial sales force team for Abecma;
 • obtain and maintain third-party coverage or adequate reimbursement for Abecma;
 • achieve market acceptance of Abecma, in the medical community and with third-party payors; and
 • have Abecma included in accepted clinical guidelines for the conditions for which Abecma is intended to target.
 Furthermore, we expect to incur additional sales and marketing costs as we and our partner BMS commercialize Abecma pursuant to our co-development and co-promotion agreement. Even if we expend these costs, Abecma may not be commercially successful.
 If we are unable to establish sales and marketing capabilities or enter into agreements with third parties to sell and market any future approved products, we may not be successful in commercializing those products if and when they are approved.
 We do not currently have an infrastructure for the sale, marketing, market access, patient service and distribution of pharmaceutical products. In order to market any future products that receive regulatory approval from the FDA or any other regulatory authority outside the United States, we must build our sales, marketing, managerial and other non-technical capabilities, or arrange with third parties to perform these services. There are risks involved with both establishing our own commercial capabilities and entering into arrangements with third parties to perform these services. For example, recruiting and training a sales force or reimbursement specialists is expensive and time-consuming and could delay any product candidate launch. If commercialization is delayed or does not occur, we would have prematurely or unnecessarily incurred such expenses. This may be costly, and our investment would be lost if we cannot retain or reposition our commercialization personnel.

 If we enter into arrangements with third parties to perform sales, marketing, commercial support and distribution services, our product revenue or the profitability of product revenue may be lower than if we were to market and sell any future products ourselves. In addition, we may fail to enter into arrangements with third parties to commercialize Abecma or any future product candidates or may be unable to do so on terms that are favorable to us. We may have little control over such third parties, and any of them may fail to devote the necessary resources and attention to sell and market any future products effectively. If we do not establish commercialization capabilities successfully, either on our own or in collaboration with third parties, or if we are unable to do so on commercially reasonable terms, we will not be successful in commercializing any future product candidates if approved and our business, prospects, financial condition and results of operations will be materially harmed.
 Abecma or any future approved products may not achieve broad market acceptance by patients, physicians, healthcare payors or others in the medical community, which would limit the revenue that we recognize from their sales.
 The commercial success of Abecma and any future products that may be approved by the FDA or other applicable regulatory authorities outside the United States, will depend upon the awareness and acceptance of these products among the medical community, including patients, physicians, and healthcare payors. If Abecma or any future products do not achieve an adequate level of acceptance by patients, physicians, healthcare payors and others in the medical community, we may not recognize sufficient revenue to become, or remain, profitable. Market acceptance of Abecma and any future products, will depend on a number of factors, including, among others:
 • the efficacy and safety of our products as demonstrated in clinical trials;
 • the clinical indications for which our products are approved, including our ability to obtain regulatory approval for Abecma in additional indications;
 • product labeling or product insert requirements of the FDA or other regulatory authorities, including the expansion of the label for Abecma;
 • limitations or warnings contained in the labeling approved by the FDA or other applicable regulatory authorities;
 • our ability to educate physicians on treatment sequencing and the emerging data supporting the use of BCMA-directed CAR Ts before other BCMA-targeted therapies;
 • any restrictions on the use of Abecma or any future products together with other medications or restrictions on the use of our products in certain types of patients;
 • the prevalence and severity of any adverse effects associated with Abecma or any future products;
 • the size of the target patient population, and the willingness of the target patient population to try new therapies and of physicians to prescribe these therapies;
 • the safety, efficacy, cost, and other potential advantages of our products compared to other available therapies;
 • relative convenience and ease of administration, including as compared to alternative treatments and competitive products;
 • our ability to generate cost effectiveness data that supports a profitable price;
 • our ability to obtain sufficient reimbursement and pricing by third-party payors and government authorities;
 • the willingness of patients to pay out-of-pocket in the absence of sufficient payor coverage;
 • the timing of market introduction of our products as well as competitive products;

 • our ability to competitively differentiate Abecma's real-world safety, efficacy and product reliability and predictability profile;
 • the effectiveness of our sales and marketing strategies; or
 • publicity concerning our products or competing products and treatments.
 If Abecma or any future products do not achieve an adequate level of acceptance by patients, physicians and payors, we may not recognize sufficient revenue from our product candidates to become or remain profitable. Before granting reimbursement approval, healthcare payors may require us to demonstrate that future products, in addition to treating these target indications, also provide incremental health benefits to patients. Our efforts to educate the medical community and third-party payors about the benefits of Abecma or any future products may require significant resources and may never be successful.
 Reimbursement may be limited or unavailable in certain market segments for Abecma and our future product candidates, which could make it difficult for us to sell our products profitably. Price controls may be imposed in foreign markets, which may harm our future profitability.
 In the United States and markets in other countries, patients generally rely on third-party payors to reimburse all or part of the costs associated with their treatment. Adequate coverage and reimbursement from governmental healthcare programs, such as Medicare and Medicaid, and commercial payors is critical to new product acceptance. Market acceptance and sales of Abecma and any approved future product candidates will depend significantly on the availability of adequate coverage and reimbursement from third-party payors and government authorities and may be affected by existing and future health care reform measures. Government authorities and third-party payors, such as private health insurers and health maintenance organizations, decide which drugs they will pay for and establish reimbursement levels. There is also significant uncertainty related to the insurance coverage and reimbursement of newly approved products and coverage may be more limited than the purposes for which the medicine is approved by the FDA or comparable foreign regulatory authorities. For more information, see the section of this Annual Report titled "Business – Government Regulations – Pricing, Coverage and Reimbursement."
 In the United States, Medicare and Medicaid are significant third party payors. Medicare is administered by the CMS, an agency within the HHS, and Medicaid is administered jointly by CMS and the individual states. Obtaining adequate coverage and reimbursement under Medicare and Medicaid is important for new drug products. Additionally, private payors may adopt coverage policies or reimbursement methodologies similar to Medicare. Reimbursement by a third-party payer may depend upon a number of factors, including the third-party payor's determination that use of a product is: a covered benefit under its health plan; safe, effective and medically necessary; appropriate for the specific patient; cost-effective; and neither experimental nor investigational. Novel and expensive cell therapies like CAR-T cell therapies have experienced and continue to experience coverage and reimbursement challenges. For example, Medicare only covers CAR-T cell therapies that meet specific criteria set forth in a national coverage decision. Other third party payors may impose coverage criteria more extensive than compliance with FDA labeling. We may have to negotiate coverage and reimbursement on a case-by case basis. Reimbursement, particularly if the cost of the therapy is reimbursed as part of a standard procedure, may not be adequate.
 Obtaining coverage and reimbursement approval for a product from a government or other third-party payor is a time consuming and costly process that could require us to provide supporting scientific, clinical and cost-effectiveness data for the use of our products to the payor. We or our partners may not be able to provide data sufficient to gain acceptance with respect to coverage and reimbursement. We cannot be sure that coverage or adequate reimbursement will be available for any future product candidates. Also, we cannot be sure that reimbursement amounts will not reduce the demand for, or the price of, future products. If reimbursement is not available or is available only to limited levels, we may not be able to commercialize any future products. In addition, in the United States, third-party payors are increasingly attempting to contain health care costs by limiting both coverage and the level of reimbursement of new drugs. As a result, significant uncertainty exists as to whether and how much third-party payors will reimburse patients for their use of newly approved drugs, which in turn will put pressure on the pricing of drugs.

 Net prices for drugs may be reduced by mandatory discounts or rebates required by government healthcare programs or private payors and by any future relaxation of laws that presently restrict imports of drugs from countries where they may be sold at lower prices than in the United States. Increasingly, third-party payors are requiring that drug companies provide them with predetermined discounts from list prices and are challenging the prices charged for medical products. We cannot be sure that reimbursement will be available for any product candidate that we commercialize and, if reimbursement is available, the level of reimbursement. In addition, many pharmaceutical manufacturers must calculate and report certain price reporting metrics to the government, such as average sales price, or ASP, and best price. Penalties may apply in some cases when such metrics are not submitted accurately and timely. Further, these prices for drugs may be reduced by mandatory discounts or rebates required by government healthcare programs.
 In some countries, particularly member states of the European Union, the pricing of prescription drugs is subject to governmental control. In these countries, pricing negotiations with governmental authorities can take considerable time after receipt of marketing approval for a product. In addition, there can be considerable pressure by governments and other stakeholders on prices and reimbursement levels, including as part of cost containment measures. Political, economic and regulatory developments may further complicate pricing negotiations, and pricing negotiations may continue after reimbursement has been obtained. Reference pricing used by various European Union member states and parallel distribution, or arbitrage between low-priced and high-priced member states, can further reduce prices. In some countries, we or our partners may be required to conduct a clinical trial or other studies that compare the cost-effectiveness of our product candidates to other available therapies in order to obtain or maintain reimbursement or pricing approval. Publication of discounts by third-party payors or authorities may lead to further pressure on the prices or reimbursement levels within the country of publication and other countries. If reimbursement of our products is unavailable or limited in scope or amount, or if pricing is set at unsatisfactory levels, our business could be harmed.
 Even though Abecma has obtained marketing approval, it, and any future approved product, will remain subject to regulatory scrutiny.
 Abecma and any future product candidates for which we obtain marketing approval will be subject to extensive and ongoing regulatory requirements governing, among other things, the research, development, testing, manufacturing, labeling, packaging, distribution, storage, advertising, promotion, import, export, recordkeeping, monitoring, and reporting of our products. These requirements include submissions of safety and other postmarketing information and reports, facility registration and drug listing requirements, as well as continued compliance with GMP. Even if we, BMS or any other of our collaborators obtain marketing approval in a jurisdiction, regulatory authorities may still impose significant restrictions on the indicated uses or marketing of any approved products, or impose ongoing requirements for potentially costly post-approval studies, post-market surveillance or patient or drug restrictions. Additionally, the holder of an approved BLA is obligated to monitor and report adverse events and any failure of a product to meet the specifications in the BLA. The holder of an approved BLA must also submit new or supplemental applications and obtain FDA approval for certain changes to the approved product, product labeling or manufacturing process. Advertising and promotional materials must comply with FDA rules and are subject to FDA review, in addition to other potentially applicable federal and state laws.
 In addition, product manufacturers and their facilities are subject to payment of user fees and continual review and periodic inspections by the FDA and other regulatory authorities for compliance with GMP and adherence to commitments made in the BLA. If we, our collaborators, or a regulatory agency discovers previously unknown problems with a product such as adverse events of unanticipated severity or frequency, or problems with the facility where the product is manufactured, a regulatory agency may impose restrictions relative to that product or the manufacturing facility, including requiring recall or withdrawal of the product from the market or suspension of manufacturing. Additionally, sponsors of approved drugs and biologics must provide 6 months' notice to the FDA of any changes in marketing status, such as the withdrawal of a drug, and failure to do so could result in the FDA placing the product on a list of discontinued products.
 If we fail to comply with applicable regulatory requirements following marketing approval for a product, a regulatory agency may:

 • impose restrictions on the marketing or manufacturing of our products, withdraw the product from the market, or impose a voluntary or mandatory product recall;
 • impose limitations on approved uses or additional warnings, contraindications, or other safety information, or a REMS;
 • require us and/or BMS to conduct additional post-market clinical trials to assess the product safety;
 • issue a warning letter asserting that we are in violation of the law;
 • seek an injunction or impose civil or criminal penalties or monetary fines;
 • suspend or withdraw marketing approval;
 • suspend any ongoing clinical studies;
 • refuse to approve a pending marketing application, such as a BLA or supplements to a BLA submitted by us;
 • seize product;
 • refuse to permit the import or export of product; or
 • refuse to allow us to enter into supply contracts, including government contracts.
 Any government investigation of alleged violations of law could require us to expend significant time and resources in response and could generate negative publicity. The occurrence of any event or penalty described above may inhibit our ability to commercialize any approved product and recognize revenues.
 Regulatory approval by the FDA or comparable foreign regulatory authorities is limited to those specific indications and conditions for which approval has been granted, and we may be subject to substantial fines, criminal penalties, injunctions, or other enforcement actions if we are determined to be promoting our products for unapproved or "off-label" uses, or in a manner inconsistent with the approved labeling, resulting in damage to our reputation and business.
 We must comply with requirements concerning advertising and promotion for Abecma and any future product for which we or our collaborators obtain marketing approval. Post-approval marketing and promotional communications with respect to therapeutics are subject to a variety of legal and regulatory restrictions and continuing review by the FDA or comparable foreign regulatory authorities, Department of Justice, HHS, Office of Inspector General, state attorneys general, members of Congress, and the public. When the FDA or comparable foreign regulatory authorities issue a regulatory approval for a product candidate, the regulatory approval is limited to those specific uses and indications for which a product is approved. If we or our collaborators are not able to obtain FDA or comparable foreign regulatory authority approval for desired uses or indications for our products or any future products, we and our collaborators may not market or promote them for those indications and uses, referred to as off-label uses, and our business, financial condition, results of operations, stock price and prospects will be materially harmed. We also must sufficiently substantiate any claims that we make for our products, including claims comparing our products to other companies' products, and must abide by the FDA or a comparable foreign regulatory authority's strict requirements regarding the content of promotion and advertising.
 While physicians may choose to prescribe products for uses that are not described in the product's labeling and for uses that differ from those tested in clinical trials and approved by the regulatory authorities, we and any third parties engaged on our behalf are prohibited from marketing and promoting the products for indications and uses that are not specifically approved by the FDA or comparable foreign regulatory authorities. Regulatory authorities in the United States generally do not restrict or regulate the behavior of physicians in their choice of treatment within the practice of medicine. Regulatory authorities do, however, restrict communications by biopharmaceutical companies concerning off-label use.

 If we are found to have impermissibly promoted our current product or any future product, we may become subject to significant liability and government fines. The FDA and other agencies actively enforce the laws and regulations regarding product promotion, particularly those prohibiting the promotion of off-label uses, and a company that is found to have improperly promoted a product may be subject to significant sanctions. The federal government has levied large civil and criminal fines against companies for alleged improper promotion and has enjoined several companies from engaging in off-label promotion. The FDA has also requested that companies enter into consent decrees or permanent injunctions under which specified promotional conduct is changed or curtailed.
 Furthermore, the use of our products for indications other than those approved by the FDA or comparable foreign regulatory authorities may not effectively treat such conditions. Any such off-label use of our products could harm our reputation in the marketplace among physicians and patients. There may also be increased risk of injury to patients if physicians attempt to use our products for these uses for which they are not approved, which could lead to product liability suits that that might require significant financial and management resources and that could harm our reputation.
 We are subject, directly or indirectly, to federal and state healthcare fraud and abuse laws, false claims laws and health information privacy and security laws. If we are unable to comply, or have not fully complied, with such laws, we could face substantial penalties, reputational harm, and diminished profits and future earnings.
 In the United States, the research, manufacturing, distribution, sale, and promotion of drugs and biologic products are subject to regulation by various federal, state, and local authorities in addition to FDA, including CMS, other divisions of the HHS, (e.g., the Office of Inspector General), the United States Department of Justice offices of the United States Attorney, the Federal Trade Commission and state and local governments. For more information, see the section of this Annual Report titled "Business – Government Regulation – Healthcare and Privacy Laws."
 We are subject to state and foreign equivalents of these healthcare laws and regulations, among others, some of which may be broader in scope and may apply regardless of the payor. Many U.S. states have adopted laws similar to the federal Anti-Kickback Statute and False Claims Act, and may apply to our business practices, including, but not limited to, research, distribution, sales or marketing arrangements and claims involving healthcare items or services reimbursed by non-governmental payors, including private insurers. In addition, some states have passed laws that require pharmaceutical companies to comply with the May 2003 Office of Inspector General Compliance Program Guidance for Pharmaceutical Manufacturers and/or the Pharmaceutical Research and Manufacturers of America's Code on Interactions with Healthcare Professionals. Several states also impose other marketing restrictions or require pharmaceutical companies to make disclosures related to financial interactions with healthcare providers, marketing expenditures or prices to the state and/or require the registration of pharmaceutical sales representatives. State laws also govern the privacy and security of health information in some circumstances, many of which differ from each other in significant ways and often are not preempted by HIPAA, thus complicating compliance efforts. There are ambiguities as to what is required to comply with these state requirements and if we fail to comply with an applicable state law requirement we could be subject to penalties. Finally, there are state and foreign laws governing the privacy and security of health information, many of which differ from each other in significant ways and often are not preempted by HIPAA, thus complicating compliance efforts.
 These laws apply to, among other things, our sales, marketing and educational programs. State and federal regulatory and enforcement agencies continue actively to investigate violations of health care laws and regulations, and the United States Congress continues to strengthen the arsenal of enforcement tools. For example, the Bipartisan Budget Act of 2018 increased the criminal and civil penalties that can be imposed for violating certain federal health care laws, including the Anti-Kickback Statute. Enforcement agencies also continue to pursue novel theories of liability under these laws. In particular, government agencies have recently increased regulatory scrutiny and enforcement activity with respect to programs supported or sponsored by pharmaceutical companies, including reimbursement and co-pay support, funding of independent charitable foundations and other programs and activities that offer benefits for patients as well as interactions with patients and patient organizations. Several investigations into such activities have resulted in significant civil and criminal settlements.
 The scope and enforcement of each of these laws is uncertain and subject to rapid change in the current environment of healthcare reform. Federal and state enforcement bodies have recently increased their scrutiny of

 interactions between healthcare companies and healthcare providers, which has led to a number of investigations, prosecutions, convictions and settlements in the healthcare industry.
 Ensuring that our internal operations and future business arrangements with third parties comply with applicable healthcare laws and regulations will involve substantial costs. We are in the process of developing a compliance program to prevent and detect non-compliance. It is possible that governmental authorities will conclude that our business practices do not comply with current or future statutes, regulations, agency guidance or case law involving applicable fraud and abuse or other healthcare laws and regulations. If our operations are found to be in violation of any of the laws described above or any other governmental laws and regulations that may apply to us, we may be subject to significant penalties, including administrative, civil and criminal penalties, damages, fines, disgorgement, the exclusion from participation in federal and state healthcare programs, individual imprisonment, reputational harm, and the curtailment or restructuring of our operations, as well as additional reporting obligations and oversight if we become subject to a corporate integrity agreement or other agreement to resolve allegations of non-compliance with these laws. Further, defending against any such actions can be costly and time consuming, and may require significant financial and personnel resources. Therefore, even if we are successful in defending against any such actions that may be brought against us, our business may be impaired. If any of the physicians or other providers or entities with whom we expect to do business are found to not be in compliance with applicable laws, they may be subject to criminal, civil or administrative sanctions, including exclusions from government funded healthcare programs and imprisonment. If any of the above occur, our ability to operate our business and our results of operations could be adversely affected.
 In the European Union, interaction between pharmaceutical companies, healthcare professionals, and patients are also governed by strict laws, regulation, industry self-regulation codes of conduct and physicians' codes of professional conduction in the individual EU member states. The provision of benefits or advantages to healthcare professionals to induce or encourage the prescription, recommendation, endorsement, purchase, supply, order or use of medicinal products is prohibited in the European Union. Also, direct-to-consumer advertising of prescription-only medicinal products is prohibited at the European Union level and in the individual member states. In addition, the UK Bribery Act applies to any company incorporated in or "carrying on business" in the UK, irrespective of where in the world the alleged bribery activity occurs, which could have implications for our interactions with physicians both in and outside of the UK. Infringement of these laws could result in substantial fines and imprisonment.
 Payments made to physicians in certain European Union member states must be publicly disclosed. Moreover, agreements with physicians often must be the subject of prior notification and approval by the physician's employer, his or her competent professional organization and/or the regulatory authorities of the individual European Union member states. These requirements are provided in the national laws, industry codes or professional codes of conduct, applicable in the European Union member states. Failure to comply with these requirements could result in reputational risk, public reprimands, administrative penalties, fines or imprisonment.
 We are subject to stringent and changing laws, regulations and standards, and contractual obligations relating to privacy, data protection, and data security. The actual or perceived failure to comply with such obligations could lead to government enforcement actions (which could include civil or criminal penalties), fines and sanctions, private litigation and/or adverse publicity and could negatively affect our operating results and business.
 We may be subject to patient and consumer privacy laws by both the federal government and the states in which we conduct our business. For example, HIPAA, as amended by HITECH, and their respective implementing regulations, imposes requirements on certain covered healthcare providers, health plans, and healthcare clearinghouses as well as their respective business associates that perform services for them that involve the use, or disclosure of, individually identifiable health information, relating to the privacy, security and transmission of individually identifiable health information. HITECH also created new tiers of civil monetary penalties, amended HIPAA to make civil and criminal penalties directly applicable to business associates, and gave state attorneys general new authority to file civil actions for damages or injunctions in federal courts to enforce the federal HIPAA laws and seek attorneys' fees and costs associated with pursuing federal civil actions. In addition to HIPAA, as amended by HITECH, and their respective implementing regulations, at the federal level, failing to take appropriate steps to keep consumers' personal information secure may constitute unfair acts or practices in or affecting commerce in violation of Section 5(a) of the Federal Trade Commission Act (the FTCA), 15 U.S.C § 45(a). The

 FTC expects a company's data security measures to be reasonable and appropriate in light of the sensitivity and volume of consumer information it holds, the size and complexity of its business and the cost of available tools to improve security and reduce vulnerabilities.
 Regulators and legislators in the U.S. are also increasingly scrutinizing and restricting certain personal data transfers and transactions involving foreign countries. For example, the Biden Administration's executive order Preventing Access to Americans' Bulk Sensitive Personal Data and United States Government-Related Data by Countries of Concern as implemented by Department of Justice regulations issued in December 2024, prohibits data brokerage transactions involving certain sensitive personal data categories, including health data, genetic data, and biospecimens, to countries of concern, including China. The regulations also restrict certain investment agreements, employment agreements and vendor agreements involving such data and countries of concern, absent specified cybersecurity controls. Actual or alleged violations of these regulations may be punishable by criminal and/or civil sanctions, and may result in exclusion from participation in federal and state programs.
 In addition, certain state laws govern privacy and security of personal information. For example, California enacted the CCPA, which, effective January 1, 2023, created new individual privacy rights for California consumers (as defined in the law) and placed increased privacy and security obligations on entities handling personal data of consumers or households. The CCPA requires covered companies to provide certain disclosures to consumers about its data collection, use and sharing practices, and to provide affected California residents with ways to opt-out of certain sales or transfers of personal information. While there is currently an exception for protected health information that is subject to HIPAA, as currently written, the CCPA may impact our business activities.
 Further, CPRA took effect on January 1, 2023 and amended the CCPA by creating additional obligations with respect to processing and storing personal information. These additional obligations have included expanding consumers' rights with respect to certain categories of sensitive personal information and by establishing the California Privacy Protection Act to enforce the CCPA.
 The CCPA and CPRA mark the beginning of a trend toward more stringent privacy legislation in the U.S., which could increase our potential liability and adversely affect our business. Already, numerous states, including Virginia, Colorado, Connecticut, New Jersey, New Hampshire and others, have adopted comprehensive privacy laws. While these laws incorporate many similar concepts to those of the CCPA, there are also several key differences in the scope, application, and enforcement of the law that will change the operational practices of regulated businesses. The new laws will, among other things, impact how regulated businesses collect and process personal sensitive data, conduct data protection assessments, transfer personal data to affiliates, and respond to consumer rights requests. There are also states that are specifically regulating health information. For example, Washington's My Health My Data Act, which became effective on March 31, 2024, regulates the collection and sharing of health information and has a private right of action, which further increases the relevant compliance risk. Connecticut and Nevada have also passed similar laws regulating consumer health data.
 The existence of a patchwork of privacy laws in different states will make our compliance obligations more complex and costly and may increase the likelihood that we may be subject to enforcement actions or otherwise incur liability for noncompliance.
 Our operations may also be subject to European data privacy laws, regulations and guidelines. The collection, use, storage, disclosure, transfer, or other processing of personal information regarding individuals in the EEA and UK, including personal health data, is subject to the EU General Data Protection Regulation, or EU GDPR, with respect to the EEA and the UK General Data Protection Regulation and UK Data Protection Act 2018 with respect to the UK, or UK GDPR, and collectively with the EU GDPR referred to as the "GDPR" in this document unless specified otherwise. The GDPR is wide-ranging in scope and imposes numerous requirements on companies that process personal information, including requirements relating to processing of special categories of personal information (such as health data), relying on a legal basis or condition for processing personal information, where required obtaining consent of the individuals to whom the personal information relates, providing information to individuals regarding data processing activities, conducting privacy impact assessments for "high risk" processing, implementing safeguards to protect the security and confidentiality of personal information, implementing limitations on the retention of personal information, providing mandatory notification of data breaches, and taking

 certain measures when engaging third-party processors. The GDPR also imposes strict rules on the transfer of personal information to countries outside the EEA and UK to non-adequate territories, including the United States in certain circumstances unless derogation exists or a valid GDPR transfer mechanism (for example, the European Commission approved Standard Contractual Clauses, or SCCs, and the UK International Data Transfer Agreement/Addendum, or UK IDTA) have been put in place. Where relying on the SCCs /UK IDTA for data transfers, we may also be required to carry out transfer impact assessments to assess whether the recipient is subject to local laws which allow public authority access to personal information. Failure to comply with the GDPR, and any supplemental EEA Member State or UK national data protection laws which may apply by virtue of the location of the individuals whose personal information we collect, may result in substantial penalties, including potential fines of up to 20 million ( 17.5 million for the UK GDPR) or 4% of annual global revenues for the preceding financial year, whichever is greater. The GDPR also confers a private right of action on data subjects and consumer associations to lodge complaints with supervisory authorities, seek judicial remedies, and obtain compensation for damages resulting from violations of the GDPR. The GDPR increases our responsibility and liability in relation to personal information that we process where such processing is subject to the GDPR, and requires us to put in place additional mechanisms to ensure compliance with the GDPR, including as implemented by individual countries. Compliance with the GDPR will be a rigorous and time-intensive process that may increase our cost of doing business or require us to change our business practices, and despite those efforts, there is a risk that we may be subject to fines and penalties, litigation, and reputational harm in connection with our European activities.
 We face intense competition and rapid technological change and the possibility that our competitors may develop therapies that are more advanced or effective than ours, which may adversely affect our financial condition and our ability to successfully commercialize Abecma and any future products. If our competitors obtain orphan drug exclusivity for products that regulatory authorities determine constitute the same drug and treat the same indications as Abecma or any future products, we may not be able to have competing products approved by the applicable regulatory authority for a significant period of time.
 We are engaged in the development of cell and gene therapies for cancer and this field is competitive and rapidly changing. We have competitors both in the United States and internationally, including major multinational pharmaceutical companies, biotechnology companies and universities and other research institutions. For example, one such competitive product, Janssen and Legend Biotech's ciltacabtagene autoleucel, an anti-BCMA CAR T cell therapy marketed as Carvykti, was approved by the FDA in February 2022. Many of our competitors have substantially greater financial, technical and other resources, such as larger research and development staff, manufacturing capabilities, experienced marketing and manufacturing organizations. Competition may increase further as a result of advances in the commercial applicability of technologies and greater availability of capital for investment in these industries. Our competitors may succeed in developing, acquiring or licensing on an exclusive basis, products that are more effective, safer, or less costly than any products that we may develop, or achieve patent protection, marketing approval, product commercialization and market penetration earlier than us. Additionally, technologies developed by our competitors may render our product candidates uneconomical or obsolete, and we may not be successful in marketing our product candidates against competitors.
 Even if we are successful in achieving marketing approval to commercialize a product candidate faster than our competitors, we may face competition from biosimilars due to the changing regulatory environment. In the United States, the Biologics Price Competition and Innovation Act of 2009 created an abbreviated approval pathway for biological products that are demonstrated to be "highly similar," or biosimilar, to or "interchangeable" with an FDA-approved biological product. This pathway could allow competitors to reference data from biological products already approved after 12 years from the time of approval. In Europe, the European Commission has granted marketing authorizations for several biosimilars pursuant to a set of general and product class-specific guidelines for biosimilar approvals issued over the past few years. In Europe, a competitor may reference data from biological products already approved, but will not be able to get on the market until 10 years after the time of approval. This 10-year period will be extended to 11 years if, during the first eight of those 10 years, the marketing authorization holder obtains an approval for one or more new therapeutic indications that bring significant clinical benefits compared with existing therapies. In addition, companies may be developing biosimilars in other countries that could compete with our products. If competitors are able to obtain marketing approval for biosimilars referencing our products, our products may become subject to competition from such biosimilars, with the attendant competitive

 pressure and consequences. Expiration or successful challenge of our applicable patent rights could also trigger competition from other products, assuming any relevant exclusivity period has expired.
 In addition, although Abecma has been granted orphan drug status by the FDA and EMA, there are limitations to the exclusivity. Under the Orphan Drug Act, the FDA may grant orphan designation to a biologic intended to treat a rare disease or condition, defined as a disease or condition with a patient population of fewer than 200,000 in the United States, or a patient population greater than 200,000 in the United States when there is no reasonable expectation that the cost of developing and making available the biologic in the United States will be recovered from sales in the United States for that biologic. In the United States, the exclusivity period for orphan drugs is seven years (with limited exceptions), and for biologics, pediatric exclusivity adds six months to any existing exclusivity periods. In Europe, orphan drugs may be able to obtain 10 years of marketing exclusivity and up to an additional two years on the basis of qualifying pediatric studies. However, orphan exclusivity may be reduced to six years if the drug no longer satisfies the original designation criteria. Additionally, a marketing authorization holder may lose its orphan exclusivity for a number of reasons, including if it consents to a second orphan drug application, its request for designation is found to be materially defective, or if the marketing authorization holder cannot supply enough drug. Orphan drug exclusivity also can be lost when a second applicant demonstrates its drug is "clinically superior" to the original orphan drug, in that it is shown to be safer, more effective, or makes a major contribution to patient care compared with the product that has orphan exclusivity. Generally, if a product with an orphan drug designation receives the first marketing approval for the indication for which it has such designation, the product is entitled to a period of marketing exclusivity, which precludes the FDA or the European Commission from approving another marketing application for a product that constitutes the same drug treating the same indication for that marketing exclusivity period, except in limited circumstances. If another sponsor receives such approval before we do (regardless of our orphan drug designation), we will be precluded from receiving marketing approval for our product for the exclusivity period for the applicable indication.
 Finally, as a result of the expiration or successful challenge of our patent rights, we could face more litigation with respect to the validity and/or scope of patents relating to our competitors' products. The availability of our competitors' products could limit the demand, and the price we are able to charge, for any products that we may develop and commercialize.
 We face potential product liability, and, if successful claims are brought against us, we may incur substantial liability and costs. If the use of Abecma or any of our product candidates and, if approved, future products harms patients, or is perceived to harm patients even when such harm is unrelated to such product candidate or product, our marketing approvals could be revoked or otherwise negatively impacted and we could be subject to costly and damaging product liability claims.
 The use of Abecma and future product candidates in clinical studies and the sale of Abecma or any future products exposes us to the risk of product liability claims. Product liability claims might be brought against us by patients participating in clinical trials, consumers, healthcare providers, pharmaceutical companies or others selling or otherwise coming into contact with our product or product candidates. There is a risk that Abecma or any future product for which we obtain marketing approval may induce adverse events. If we cannot successfully defend against product liability claims, we could incur substantial liability and costs. In addition, regardless of merit or eventual outcome, product liability claims may result in:
 • impairment of our business reputation;
 • withdrawal of clinical study participants;
 • costs due to related litigation;
 • distraction of management's attention from our primary business;
 • substantial monetary awards to patients or other claimants;
 • the inability to develop our product candidates or commercialize any approved product; and

 • decreased demand for any approved product.
 We carry product liability insurance and we believe our product liability insurance coverage is sufficient in light of our current clinical programs; however, we may not be able to maintain insurance coverage at commercially reasonable cost or in sufficient amounts to protect us against losses due to liability. On occasion, large judgments have been awarded in class action lawsuits based on drugs or medical treatments that had unanticipated adverse effects. A successful product liability claim or series of claims brought against us could cause our stock price to decline and, if judgments exceed our insurance coverage, could adversely affect our results of operations and business.
 Patients with the diseases targeted by Abecma and our product candidates are often already in severe and advanced stages of disease and have both known and unknown significant pre-existing and potentially life-threatening health risks. During the course of treatment, patients may suffer adverse events, including death, for reasons that may be related to Abecma or our product candidates. Such events could subject us to costly litigation, require us to pay substantial amounts of money to injured patients, delay, negatively impact or end our opportunity to receive or maintain marketing approval for any approved product, or require us to suspend or abandon our commercialization efforts for any approved product. Even in a circumstance in which we do not believe that an adverse event is related to our products the investigation into the circumstance may be time-consuming or inconclusive. These investigations may impact and limit the type of marketing approval our product candidates may receive or any approved product maintains. As a result of these factors, a product liability claim, even if successfully defended, could have a material adverse effect on our business, financial condition or results of operations.
 Healthcare legislative reform measures may have a material adverse effect on our business and results of operations.
 The United States and many foreign jurisdictions have enacted or proposed legislative and regulatory changes affecting the healthcare system that could prevent or delay marketing approval of our product candidates or any future product candidates, restrict or regulate post-approval activities and affect our ability to profitably sell any product for which we obtain marketing approval. Changes in regulations, statutes or the interpretation of existing regulations could impact our business in the future by requiring, for example: (i) changes to our manufacturing arrangements; (ii) additions or modifications to product labeling; (iii) the recall or discontinuation of our products; or (iv) additional record-keeping requirements. If any such changes were to be imposed, they could adversely affect the operation of our business. For more information, see the section of this Annual Report titled "Business – Government Regulation – Healthcare Reform."
 There have been, and likely will continue to be, legislative and regulatory proposals at the foreign, federal and state levels directed at broadening the availability of healthcare and containing or lowering the cost of healthcare. The implementation of cost containment measures or other healthcare reforms may prevent us from being able to generate revenue, attain profitability, or commercialize our product candidates. Such reforms could have an adverse effect on anticipated revenue from product candidates that we may successfully develop and for which we may obtain regulatory approval and may affect our overall financial condition and ability to develop product candidates.
 We cannot predict the initiatives that may be adopted in the future. The continuing efforts of the government, insurance companies, managed care organizations and other payors of healthcare services to contain or reduce costs of healthcare and/or impose price controls may adversely affect:
 • the demand for our product candidates, if we obtain regulatory approval;
 • our ability to set a price that we believe is fair for our products, if licensed;
 • our ability to generate revenue and achieve or maintain profitability;
 • the level of taxes that we are required to pay; and
 • the availability of capital.

 Any reduction in reimbursement from Medicare or other government programs may result in a similar reduction in payments from private payors, which may adversely affect our future profitability.
 We expect that additional U.S. federal healthcare reform measures will be adopted in the future, any of which could limit the amounts that the U.S. federal government will pay for healthcare drugs and services, which could result in reduced demand for our drug candidates or additional pricing pressures. Individual states in the United States have also become increasingly active in passing legislation and implementing regulations designed to control pharmaceutical and biological product pricing, including price or patient reimbursement constraints, discounts, restrictions on certain drug access and marketing cost disclosure and transparency measures, and designed to encourage importation from other countries and bulk purchasing. Legally mandated price controls on payment amounts by third-party payors or other restrictions could harm our business, financial condition, results of operations and prospects. In addition, regional healthcare authorities and individual hospitals are increasingly using bidding procedures to determine what pharmaceutical products and which suppliers will be included in their prescription drug and other healthcare programs. This could reduce the ultimate demand for our drugs or put pressure on our drug pricing, which could negatively affect our business, financial condition, results of operations and prospects.
 Risks Related to Our Business Operations
 Our business is affected by macroeconomic conditions, including rising inflation, interest rates, supply chain constraints and significant political, trade, or regulatory developments.
 Various macroeconomic factors could adversely affect our business and the results of our operations and financial condition, including changes in inflation, interest rates and overall economic conditions and uncertainties such as those resulting from the current and future conditions in the global financial markets. We may experience business interruptions or negative market conditions arising out of global crises, including international conflicts, or future public health events. If inflation or other factors were to significantly increase our business costs, our ability to develop our current pipeline and new products may be negatively affected. Interest rates, the liquidity of the credit markets and the volatility of the capital markets could also affect the operation of our business and our ability to raise capital on favorable terms, or at all, in order to fund our operations. Significant political, trade, or regulatory developments such as those stemming from the change in U.S. federal administration, are difficult to predict and may have a material adverse effect on us. Similarly, changes in U.S. federal policy that affect the geopolitical landscape could give rise to circumstances outside our control that could have negative impacts on our business operations. For example, in February 2025, the U.S. imposed a 25% tariff on imports from Canada and Mexico, which were subsequently suspended for a period of one month, and a 10% additional tariff on imports from China. Historically, tariffs have led to increased trade and political tensions. In response to tariffs, other countries have implemented retaliatory tariffs on U.S. goods. Political tensions as a result of trade policies could reduce trade volume, investment, technological exchange and other economic activities between major international economies, resulting in a material adverse effect on global economic conditions and the stability of global financial markets. Any changes in political, trade, regulatory, and economic conditions, including U.S. trade policies, could have a material adverse effect on our financial condition or results of operations. Similarly, these macroeconomic factors could affect the ability of third-party suppliers and manufacturers to manufacture Abecma as well as clinical trial materials.
 Adverse developments affecting the financial services industry, such as actual events or concerns involving liquidity, defaults or non-performance by financial institutions or transactional counterparties, could adversely affect our business, financial condition and results of operations.
 Actual events involving limited liquidity, defaults, non-performance or other adverse developments that affect financial institutions, transactional counterparties or other companies in the financial services industry generally, or concerns or rumors about any events of these kinds or other similar risks, have in the past led and may in the future lead to market-wide liquidity problems. For example, in March 2023, the Federal Deposit Insurance Corporation took control and was appointed receiver of Silicon Valley Bank and Signature Bank after each bank was unable to continue its operations. Although we assess our banking relationships as we believe necessary or appropriate, our access to funding sources in amounts adequate to finance or capitalize our current and projected future business operations could be significantly impaired by the financial institutions with which we have arrangements directly, or

 the financial services industry or economy in general. These factors could include, among others, events such as liquidity constraints or failures, the ability to perform obligations under various types of financial, credit or liquidity agreements or arrangements, disruptions or instability in the financial services industry or financial markets, or concerns or negative expectations about the prospects for companies in the financial services industry.
 Our prospects for success depend on our ability to retain our management team and to attract, retain and motivate qualified personnel.
 We are highly dependent on our management and personnel. Despite our efforts to retain valuable employees, members of our management and scientific and development teams may terminate their employment with us on short notice. The loss of the services of any of our executive officers, other key employees and other scientific and medical advisors and an inability to find suitable replacements could result in delays in product development and harm our business. Our success also depends on our ability to continue to attract, retain and motivate highly skilled junior, mid-level and senior managers as well as junior, mid-level and senior scientific and medical personnel.
 We may not be able to attract, recruit or retain qualified management and scientific and medical personnel in the future due to the intense competition for a limited number of qualified personnel among biopharmaceutical, biotechnology, pharmaceutical and other businesses. Many of the other pharmaceutical companies that we compete against for qualified personnel have greater financial and other resources, different risk profiles and a longer history in the industry than we do. They also may provide more diverse opportunities and better chances for career advancement. Some of these characteristics may be more appealing to high quality candidates than what we may be able to offer. We also experience competition for the hiring of scientific personnel from universities and research institutions. The failure to succeed in preclinical or clinical studies may make it more challenging to recruit and retain qualified personnel. In addition, in order to induce employees to continue their employment with us, we have provided equity awards that vest over time and the value to our employees of such equity awards may be significantly affected by movements in our stock price that are beyond our control and may be at any time insufficient to counteract more lucrative offers from other companies. If we are unable to continue to attract and retain high quality personnel, the rate and success at which we can develop and commercialize product candidates will be limited.
 Our operating results may fluctuate significantly, which would have the result of making our future operating results difficult to predict and could cause our operating results to fall below expectations or our guidance.
 Our operating results will likely fluctuate from quarter to quarter and year to year and be difficult to predict. In addition, our licensing and collaboration agreements with other companies include research and development funding and milestone payments to us, and we expect that amounts earned from our collaboration agreements will be an important source of our revenues. Accordingly, our revenues will also depend on our existing collaboration and license agreements, including, in particular, our collaboration with BMS. These payments may vary significantly from quarter to quarter and any such variance could cause a significant fluctuation in our operating results from one quarter to the next.
 Further, changes in our operations, such as increased development, manufacturing and clinical trial expenses, or our undertaking of additional programs, or business activities, or entry into strategic transactions, including potential future acquisitions of products, technologies or businesses may also cause significant fluctuations in our expenses.
 The cumulative effects of these factors, will likely result in large fluctuations and unpredictability in our quarterly and annual operating results. As a result, comparing our operating results on a period-to-period basis may not be meaningful. Investors should not rely on our past results as an indication of our future performance. This variability and unpredictability could also result in our failing to meet the expectations of industry or financial analysts or investors for any period. If our revenue or operating results fall below the expectations of analysts or investors or below any forecasts we may provide to the market, or if the forecasts we provide to the market are below the expectations of analysts or investors, the price of our common stock could decline substantially. Such a stock price decline could occur even when we have met any previously publicly stated revenue or earnings guidance we may provide.

 If we fail to maintain proper and effective internal controls, our ability to produce accurate and timely financial statements could be impaired, which could result in sanctions or other penalties that would harm our business.
 We are subject to the reporting requirements of the Securities Exchange Act of 1934, or the Exchange Act, the Sarbanes-Oxley Act of 2002, or the Sarbanes-Oxley Act, and the rules and regulations of The Nasdaq Global Market. We currently qualify as an "emerging growth company." For so long as we remain an emerging growth company, we will be exempt from Section 404(b) of the Sarbanes-Oxley Act, which requires auditor attestation to the effectiveness of internal control over financial reporting. We will cease to be an emerging growth company on the date that is the earliest of (i) the last day of the fiscal year in which we have total gross annual revenues of $1.235 billion or more; (ii) December 31, 2026; (iii) the date on which we have issued more than $1 billion in nonconvertible debt during the previous three years; or (iv) the date on which we are deemed to be a large accelerated filer under the rules of the SEC. We cannot predict if investors will find our common stock less attractive because we may rely on the exemptions available to us as an emerging growth company. If some investors find our common stock less attractive as a result, there may be a less active trading market for our common stock and our stock price may be more volatile.
 We are subject to Section 404(a) of the Sarbanes-Oxley Act and, as of the expiration of our emerging growth company status, we will be broadly subject to enhanced reporting and other requirements under the Exchange Act and Sarbanes-Oxley Act. We are required to furnish, among other things, annual management assessments of the effectiveness of our internal control over financial reporting. These and other obligations place significant demands on our management, administrative and operational resources, including accounting and information technology resources. To comply with these requirements, we have implemented financial and management controls, reporting systems and procedures and maintain accounting, finance and information technology staff. Our management and other personnel devote a substantial amount of time to these compliance initiatives. Moreover, these rules and regulations carry legal and financial compliance costs and make some activities more time-consuming and costlier. If we are unable to maintain these controls, systems, and procedures, or if we are unable to retain the appropriate personnel, our ability to comply with our financial reporting requirements and other rules that apply to reporting companies could be impaired and our business, prospects, financial condition and results of operations could be harmed.
 We may discover weaknesses in our system of internal financial and accounting controls and procedures that could result in a material misstatement of our financial statements. Our internal control over financial reporting will not prevent or detect all errors and all fraud. A control system, no matter how well designed and operated, can provide only reasonable, not absolute, assurance that the control system's objectives will be met. Because of the inherent limitations in all control systems, no evaluation of controls can provide absolute assurance that misstatements due to error or fraud will not occur or that all control issues and instances of fraud will be detected.
 If we are not able to comply with the requirements of Section 404 of the Sarbanes-Oxley Act in a timely manner, or if we are unable to maintain proper and effective internal controls over financial reporting, we may not be able to produce timely and accurate financial statements. If that were to happen, our investors could lose confidence in our reported financial information, the market price of our stock could decline, and we could be subject to sanctions or investigations by the SEC or other regulatory authorities.
 Our computer systems, or those of our third-party collaborators, service providers, contractors or consultants, may fail or suffer cybersecurity incidents or data breaches, which could result in a disruption of our product candidates' development programs and have an adverse effect on our reputation, business, financial condition or results of operations.
 Our computer systems and those of our current or future third-party collaborators, service providers, contractors and consultants may fail and are vulnerable to damage from computer viruses, unauthorized access, natural disasters, terrorism, war and telecommunication and electrical failures. Like other companies in our industry, we have experienced threats and cybersecurity incidents relating to our, and our third-party vendors', data and information systems from time to time. The size and complexity of our information technology systems, and those of our collaborators, service providers, contractors and consultants, and the large amounts of information stored on those systems make those systems vulnerable to service interruptions, cybersecurity incidents, data breaches, or other

 failures, resulting from inadvertent or intentional actions by our employees or those of third-party business partners, or from cyber-attacks by malicious third parties. Attacks on information technology systems are increasing in their frequency, levels of persistence, sophistication and intensity, and they are being conducted by increasingly sophisticated and organized groups and individuals with a wide range of motives and expertise. In addition to extracting sensitive information, such attacks could include the deployment of harmful malware, ransomware, denial-of-service attacks, social engineering (including phishing attacks) and other means to affect service reliability and threaten the confidentiality, integrity and availability of information. The prevalent use of mobile devices also increases the risk of data breaches and cybersecurity incidents. If we experience a system failure, accident, cybersecurity incident or data breach that causes interruptions in our operations or the operations of third-party collaborators, service providers, contractors and consultants, it could result in significant reputational, financial, legal, regulatory, business or operational harm. For example, the loss of clinical trial data for our product candidates could result in delays in our marketing approval efforts and significantly increase our costs to recover or reproduce the data. To the extent that any disruption, data breach, or cybersecurity incident results in a loss of or damage to our data or applications or other data or applications relating to our technology or product candidates, or inappropriate disclosure of confidential or proprietary information, we could incur liabilities and the further development of our product candidates could be delayed. In addition, it is possible that unauthorized access to our data may be obtained through inadequate use of security controls by suppliers or other vendors. We rely on such third parties to implement effective security measures and identify and correct for any failures, deficiencies, data breaches, or cybersecurity incidents. Specifically, we rely on third-party service providers for management of the manufacture and delivery of drug product to patients in the commercial context, including for chain of identity and chain of custody. We also rely on third-party service providers for aspects of our internal control over financial reporting and such service providers may experience a system failure or fail to carry out their obligations in other respects, which may impact our ability to produce accurate and timely financial statements, thus harming our operating results, our ability to operate our business, and our investors' view of us. In addition, our liability insurance may not be sufficient in type or amount to cover us against claims related to failures, cybersecurity incidents, cyberattacks and other related events, including data breaches.
 Any failure or perceived failure by us or any third-party collaborators, service providers, contractors or consultants to comply with our privacy, confidentiality, data security or similar obligations to third parties, or any data breaches, cybersecurity incidents, or other disruptions that result in the unauthorized access, release or transfer of sensitive information, including personally identifiable information, may require us to notify relevant stakeholders (including affected individuals, regulators and investors) and may result in governmental investigations, enforcement actions, regulatory fines, litigation or public statements against us. These events could cause third parties to lose trust in us or could result in claims by third parties asserting that we have breached our privacy, confidentiality, data security or similar obligations, any of which could have an adverse effect on our reputation, business, financial condition or results of operations. Moreover, our contracts may not contain limitations of liability, and even where they do, there can be no assurance that limitations of liability in our contracts are sufficient to protect us from liabilities, damages, or claims related to our privacy and data security obligations. Data security incidents and other security events can be difficult to detect, and any delay in identifying them may lead to increased harm. Because the techniques used by those who may attempt to penetrate and sabotage our network security or our website change frequently and may not be recognized until launched against a target, we may be unable to anticipate these techniques. While we have implemented data security measures intended to protect our information technology systems and infrastructure, there can be no assurance that such measures will successfully prevent service interruptions, data breaches, or cybersecurity incidents. Moreover, as we outsource more of our information systems to vendors and rely more on cloud-based information systems, the related security risks will increase, and the current resources dedicated to protecting our technology and information systems may not suffice.
 Our employees may engage in misconduct or other improper activities, including violating applicable regulatory standards and requirements or engaging in insider trading, which could significantly harm our business.
 We are exposed to the risk of employee fraud or other misconduct. Misconduct by employees could include intentional failures to comply with the regulations of the FDA and applicable foreign regulators, provide accurate information to the FDA and applicable foreign regulators, comply with healthcare fraud and abuse laws and regulations in the United States and abroad, report financial information or data accurately and/or disclose

 unauthorized activities to us. In particular, research and development, sales, marketing and business arrangements in the healthcare industry are subject to considerable laws and regulations intended to prevent fraud, misconduct, kickbacks, self-dealing and other abusive practices. These laws and regulations restrict, regulate or prohibit a wide range of activities pertaining to clinical trials including the informed consent process, data integrity, and conducting the study in accordance with the investigational plan, and for approved products, pricing, discounting, marketing and promotion, sales commission, customer incentive programs and other business arrangements. Employee misconduct could also involve the improper use of, including trading on, information obtained in the course of clinical trials, which could result in regulatory sanctions and serious harm to our reputation. We have adopted a code of conduct, but it is not always possible to identify and deter employee misconduct, and the precautions we take to detect and prevent this activity may be ineffective in controlling unknown or unmanaged risks or losses or in protecting us from governmental investigations or other actions or lawsuits stemming from a failure to comply with these laws or regulations. Additionally, we are subject to the risk that a person could allege such fraud or other misconduct, even if none occurred. If any such actions are instituted against us, and we are not successful in defending ourselves or asserting our rights, those actions could have a significant impact on our business, including the imposition of significant fines or other sanctions, possible exclusions from participation in Medicare, Medicaid and other U.S. federal healthcare programs, contractual damages and reputational harm.
 If we or any contract manufacturers and suppliers we engage fail to comply with environmental, health and safety laws and regulations, we could become subject to fines or penalties or incur costs that could have a material adverse effect on the success of our business.
 We and any contract manufacturers and suppliers we engage are subject to numerous federal, state and local environmental, health and safety laws, regulations and permitting requirements, including those governing laboratory procedures; the generation, handling, use, storage, treatment and disposal of hazardous and regulated materials and wastes; the emission and discharge of hazardous materials into the ground, air and water; and employee health and safety. Under certain environmental laws, we could be held responsible for costs relating to any contamination at our current or past facilities and at third-party facilities. We also could incur significant costs associated with civil or criminal fines and penalties.
 We could be adversely affected by violations of the U.S. Foreign Corrupt Practices Act, or the FCPA, and other worldwide anti-bribery laws.
 We are subject to the FCPA, which prohibits U.S. corporations and their representatives from offering, promising, authorizing or making payments to any foreign government official, government staff member, political party or political candidate in an attempt to obtain or retain business abroad. The scope of the FCPA includes interactions with certain healthcare professionals in many countries. Other countries have enacted similar anti-corruption laws and/or regulations. In some countries in which we operate, the pharmaceutical and life sciences industries are exposed to a high risk of corruption associated with the conduct of clinical trials and other interactions with healthcare professionals and institutions. While we intend to conduct any foreign operations in compliance with the FCPA, any such activities could expose us to potential liability under the FCPA, which may result in us incurring significant criminal and civil penalties and to potential liability under the anti-corruption laws and regulations of other jurisdictions in which we operate. In addition, the costs we may incur in defending against an FCPA investigation could be significant.
 Risks Related to Ownership of Our Common Stock
 The market price of our common stock may fluctuate widely and you could lose part or all of your investment in our common stock as a result.
 Our common stock has a limited trading history and the market price has fluctuated widely, and may in the future fluctuate widely, depending upon many factors, some of which are beyond our control, including the following:
 • the pendency of the proposed acquisition by BMS and the market perception thereof;

 • the commercial performance of Abecma or any of our products that may be approved, as well as the costs associated with such activities;
 • BMS' disclosure of revenue from Abecma in its earning releases or otherwise;
 • results and timing of preclinical studies and clinical studies of Abecma or our product candidates;
 • potential approval of Abecma in earlier lines of therapy;
 • results of clinical studies of our competitors' products;
 • failure to adequately protect our trade secrets;
 • our inability to raise additional capital, if needed, and the terms on which we raise it;
 • commencement or termination of any strategic partnership or licensing arrangement;
 • regulatory developments with respect to our products or our competitors' products, including any developments, litigation or public concern about the safety of such products;
 • announcements concerning product development results, including clinical trial results, the introduction of new products or intellectual property rights of us or others;
 • actual or anticipated fluctuations in our financial condition and our quarterly and annual operating results;
 • deviations in our operating results from any guidance we may provide or the estimates of securities analysts;
 • additions and departures of key personnel;
 • the passage of legislation or other regulatory developments affecting us or our industry;
 • fluctuations in the valuation of companies perceived by investors to be comparable to us;
 • sales of our common stock by us, our insiders or our other stockholders;
 • strategic decisions by us or our competitors, such as acquisitions, divestitures, spin-offs, joint ventures, strategic investments or changes in business strategy;
 • announcement or expectation of additional financing efforts;
 • publication of research reports by securities analysts about us or our competitors or our industry and speculation regarding our company or our stock price in the financial or scientific press or in online investor communities;
 • changes in market conditions in the pharmaceutical and biotechnology sector; and
 • changes in general credit and financial markets and economic conditions.
 In addition, if the market for stocks in our industry or industries related to our industry, or the stock market in general, experiences a loss of investor confidence, the trading price of our common stock could decline for reasons unrelated to our business, results of operations, financial condition and prospects. If any of the foregoing occurs, it could cause our stock price to fall and may expose us to lawsuits that, even if unsuccessful, could be costly to defend and a distraction to management.
 In addition, a decline or volatility in the market price of our common stock may affect our willingness and ability to raise equity capital through the sale of our common stock in public and/or private offerings, which may adversely affect our ability to fund our business operations.

 If securities or industry analysts fail to initiate or maintain coverage of our stock, publish a negative report or change their recommendations regarding our stock adversely, our stock price and trading volume could decline.
 The trading market for our common stock is influenced by the research and reports that industry or securities analysts publish about us, our business, our market or our competitors. If securities or industry analysts fail to initiate coverage of our stock, the lack of exposure to the market could cause our stock price or trading volume to decline. If any of the analysts who cover us or may cover us in the future publish a negative report or change their recommendation regarding our stock adversely, or provide more favorable relative recommendations about our competitors, our stock price would likely decline. If any analyst who covers us or may cover us in the future were to cease coverage of our company or fail to regularly publish reports on us, we could lose visibility in the financial markets, which in turn could cause our stock price or trading volume to decline.
 Actual or potential sales of our common stock by our employees, including our executive officers, pursuant to pre-arranged stock trading plans could cause our stock price to fall or prevent it from increasing for numerous reasons, and actual or potential sales by such persons could be viewed negatively by other investors.
 In accordance with the guidelines specified under Rule 10b5-1 of the Securities Exchange Act of 1934, as amended, and the policies that we intend to adopt prior to the distribution regarding stock transactions, a number of our employees, including executive officers and members of our board of directors, may adopt stock trading plans pursuant to which they arrange to sell shares of our common stock from time to time in the future. Generally, sales under such plans by our executive officers and directors will require public filings. Actual or potential sales of our common stock by such persons could cause the price of our common stock to fall or prevent it from increasing for numerous reasons.
 Future sales and issuances of our common stock or rights to purchase common stock, including pursuant to our equity incentive plans, could result in additional dilution of the percentage ownership of our stockholders and could cause our stock price to fall.
 In the future, your percentage ownership in the Company may be diluted because of equity issuances for acquisitions, capital market transactions or otherwise, including equity awards that we plan to grant to our directors, officers and employees pursuant to our equity incentive plans. Such awards will have a dilutive effect on our earnings per share, which could adversely affect the market price of our common stock.
 In addition, we are authorized under our amended and restated certificate of incorporation to issue, without the approval of our stockholders, one or more classes or series of preferred stock having such designation, powers, preferences and relative, participating, optional and other special rights, including preferences over our common stock with respect to dividends and distributions, as our board of directors may determine. The terms of one or more classes or series of preferred stock could dilute the voting power or reduce the value of our common stock. For example, we could grant the holders of preferred stock the right to elect some number of directors in all events or on the happening of specified events or the right to veto specified transactions. Similarly, the repurchase or redemption rights or liquidation preferences we could assign to holders of preferred stock could affect the residual value of the common stock.
 The administrator of the 2021 Stock Option and Incentive Plan, or 2021 Plan, is authorized to exercise its discretion to effect the repricing of stock options and stock appreciation rights and there may be adverse consequences to our business if the administrator of the 2021 Plan exercises such discretion.
 Pursuant to our 2021 Plan, we are authorized to grant equity awards, including stock options and stock appreciation rights, to our employees, directors and consultants. The administrator of the 2021 Plan (which is our compensation committee) is authorized to exercise its discretion to reduce the exercise price of stock options or stock appreciation rights or effect the repricing of such awards. Although we do not anticipate needing to exercise this discretion in the near term, or at all, if the administrator of the 2021 Plan were to exercise such discretion without seeking prior stockholder approval, certain proxy advisory firms or institutional investors may be unsupportive of such actions and publicly criticize our compensation practices, and proxy advisory firms may recommend an "against" or "withhold" vote for members of our compensation committee. In addition, if we are required to hold an advisory vote on named executive officer compensation (known as the "say-on-pay" vote) at the

 time of, or subsequent to, any such repricing, it is likely that proxy advisory firms would issue an "against" recommendation on our say on pay vote and institutional investors may not be supportive of our say-on-pay vote. If proxy advisory firms or institutional investors are successful in aligning their views with our broader stockholder base and we are required to make changes to the composition of our board and its committees, or if we need to make material changes to our compensation and corporate governance practices, our business might be disrupted and our stock price might be negatively impacted. Even if we are able to successfully rationalize the exercise of such discretionary power, defending against any "against" or "withhold" recommendation for members of our compensation committee, any "against" recommendation on our say on pay vote or public criticism could be distracting to management, and responding to such positions from such firms or investors, even if remedied, can be costly and time-consuming.
 In addition, if the administrator of the 2021 Plan does determine to reprice stock options or stock appreciation rights, even absent negative reactions from proxy advisory firms and institutional investors, management attention may be diverted and we could incur significant costs, including accounting and administrative costs and attorneys' fees. We may also be required to recognize incremental compensation expense as a result of such repricing. These actions could cause our stock price to decrease and experience periods of increased volatility, which could result in material adverse consequences to our business.
 We do not expect to pay any cash dividends for the foreseeable future.
 We do not anticipate that we will pay any cash dividends to holders of our common stock in the foreseeable future. Instead, we plan to retain any earnings to maintain and expand our operations related to Abecma. In addition, any future debt financing arrangement may contain terms prohibiting or limiting the amount of dividends that may be declared or paid on our common stock. Accordingly, investors must rely on sales of their common stock after price appreciation, which may never occur, as the only way to realize any return on their investment. As a result, investors seeking cash dividends should not purchase our common stock.
 Provisions in our amended and restated certificate of incorporation and by-laws, as well as provisions of Delaware law, could make it more difficult for a third party to acquire us or increase the cost of acquiring us, even if doing so would benefit our stockholders or remove our current management.
 Our amended and restated certificate of incorporation and amended and restated bylaws contain, and Delaware law contains, provisions that may have the effect of delaying or preventing a change in control of us or changes in our management. Our amended and restated certificate of incorporation and by-laws include provisions that:
 • authorize "blank check" preferred stock, which could be issued by our board of directors without stockholder approval and may contain voting, liquidation, dividend and other rights superior to our common stock;
 • create a classified board of directors whose members serve staggered three-year terms;
 • specify that special meetings of our stockholders can be called only by our board of directors, the chairperson of our board of directors, our chief executive officer or our president;
 • prohibit stockholder action by written consent;
 • establish an advance notice procedure for stockholder approvals to be brought before an annual meeting of our stockholders, including proposed nominations of persons for election to our board of directors;
 • provide that our directors may be removed only for cause;
 • provide that vacancies on our board of directors may be filled only by a majority of directors then in office, even though less than a quorum;
 • specify that no stockholder is permitted to cumulate votes at any election of directors;
 • expressly authorize our board of directors to modify, alter or repeal our amended and restated by-laws; and

 • require supermajority votes of the holders of our common stock to amend specified provisions of our amended and restated certificate of incorporation and amended and restated by-laws.
 These provisions, alone or together, could delay or prevent hostile takeovers and changes in control or changes in our management.
 In addition, because we are incorporated in Delaware, we are governed by the provisions of Section 203 of the Delaware General Corporation Law, which limits the ability of stockholders owning in excess of 15% of our outstanding voting stock to merge or combine with us.
 Any provision of our amended and restated certificate of incorporation or amended and restated by-laws or Delaware law that has the effect of delaying or deterring a change in control could limit the opportunity for our stockholders to receive a premium for their shares of our common stock, and could also affect the price that some investors are willing to pay for our common stock.
 Our amended and restated bylaws designate certain specified courts as the sole and exclusive forums for certain disputes between us and our stockholders, which could limit our stockholders' ability to obtain a favorable judicial forum for disputes with us or our directors, officers, or employees.
 Our amended and restated bylaws provide that, unless we consent in writing to the selection of an alternative forum, the Court of Chancery of the State of Delaware, or the Chancery Court, will be the sole and exclusive forum for state law claims for (i) any derivative action or proceeding brought on our behalf, (ii) any action asserting a claim of, or a claim based on, a breach of a fiduciary duty owed by any of our directors, officers or other employees to us or our stockholders, (iii) any action asserting a claim pursuant to any provision of the Delaware General Corporation Law, our certificate of incorporation or our bylaws, (iv) any action to interpret, apply, enforce or determine the validity of our certificate of incorporation or bylaws, or (v) any action asserting a claim governed by the internal affairs doctrine, or the Delaware Forum Provision. The Delaware Forum Provision does not apply to any causes of action arising under the Securities Act of 1933, as amended, or the Securities Act, or the Exchange Act. Our amended and restated bylaws further provide that, unless we consent in writing to the selection of an alternative forum, the federal district courts of the United States of America will be the sole and exclusive forum for resolving any complaint asserting a cause of action arising under the Securities Act, or the Federal Forum Provision. Our amended and restated bylaws provide that any person or entity purchasing or otherwise acquiring any interest in shares of our capital stock is deemed to have notice of and consented to the foregoing Delaware Forum Provision and the Federal Forum Provision; provided, however, that stockholders cannot and will not be deemed to have waived our compliance with the federal securities laws and the rules and regulations thereunder.
 The Delaware Forum Provision and the Federal Forum Provision may impose additional litigation costs on stockholders in pursuing the claims identified above, particularly if the stockholders do not reside in or near the State of Delaware. Additionally, the Delaware Forum Provision and the Federal Forum Provision may limit a stockholder's ability to bring a claim in a judicial forum that it finds favorable for disputes with us or our directors, officers or other employees, which may discourage such lawsuits. In addition, while the Delaware Supreme Court ruled in March 2020 that federal forum selection provisions purporting to require claims under the Securities Act be brought in federal court are "facially valid" under Delaware law, there is uncertainty as to whether other courts will enforce our Federal Forum Provision. If the Federal Forum Provision is found to be unenforceable in an action, we may incur additional costs associated with resolving such an action. The Federal Forum Provision may also impose additional litigation costs on stockholders who assert that the provision is not enforceable or invalid. The Chancery Court or the federal district courts of the United States of America may also reach different judgments or results than would other courts, including courts where a stockholder considering an action may be located or would otherwise choose to bring the action, and such judgments may be more or less favorable to us than our stockholders.
 Risks Related to Our Separation From bluebird bio
 If the distribution, together with certain related transactions, does not qualify as a transaction that is generally tax-free for U.S. federal income tax purposes, bluebird bio and its stockholders could be subject to significant tax liabilities, and we could be required to indemnify bluebird bio for material taxes pursuant to indemnification obligations under the tax matters agreement.

 In connection with the separation and distribution, bluebird bio received a favorable private letter ruling from Internal Revenue Service, or the IRS, relating to the U.S. federal income tax treatment of the distribution. Consistent with the IRS's ruling guidelines, the IRS private letter ruling does not cover all of the issues that are relevant to determining whether the distribution is generally tax free for U.S. federal income tax purposes, including whether the distribution (i) satisfies the business purpose requirement in Section 1.355-2(b) of the Treasury Regulations, (ii) is used principally as a device for the distribution of our earnings and profits or the earnings and profits of bluebird bio or both or (iii) is part of a plan (or series of related transactions) pursuant to which one or more persons will acquire directly or indirectly stock representing a 50% or greater interest in bluebird bio or us. Accordingly, as a condition to the distribution, bluebird bio received an opinion of Goodwin Procter LLP, satisfactory to bluebird bio's board of directors, confirming that the distribution, together with certain related transactions, generally was tax-free for U.S. federal income tax purposes under Sections 355 and 368(a)(1)(D) of Internal Revenue Code, or the Code. The opinion of Goodwin Procter LLP delivered to bluebird bio and the IRS private letter ruling were based, among other things, on various facts and assumptions, as well as certain representations, statements and undertakings from us and bluebird bio (including those relating to the past and future conduct of us and bluebird bio). If any of these facts, assumptions, representations, statements or undertakings is, or becomes, inaccurate or incomplete, or if we or bluebird bio breach any of our respective covenants relating to the separation, the IRS private letter ruling and/or the opinion of Goodwin Procter LLP may be invalid. Accordingly, notwithstanding receipt of the favorable IRS private letter ruling and the opinion of Goodwin Procter LLP delivered to bluebird bio, the IRS could determine that the distribution and certain related transactions should be treated as taxable transactions for U.S. federal income tax purposes if it determines that any of the facts, assumptions, representations, statements or undertakings that were included in the request for the IRS private letter ruling or on which the opinion of Goodwin Procter LLP was based is inaccurate or incomplete or has been violated. In addition, the opinion of Goodwin Procter LLP delivered to bluebird bio represents the judgment of Goodwin Procter LLP, which is not binding on the IRS or any court. Accordingly, notwithstanding receipt by bluebird bio of the tax opinion and the favorable IRS private letter ruling referred to above, the IRS could assert that the distribution and/or certain related transactions did not qualify for tax-free treatment for U.S. federal income tax purposes.
 If the distribution, together with certain related transactions, were to fail to qualify as a transaction that is generally tax-free under Sections 355 and 368(a)(1)(D) of the Code, in general, for U.S. federal income tax purposes, bluebird bio would recognize taxable gain as if it has sold our distributed common stock in a taxable sale for its fair market value and bluebird bio stockholders who received shares of our common stock in the distribution would be subject to tax as if they had received a taxable distribution equal to the fair market value of such shares.
 In connection with the distribution, we and bluebird bio entered into a tax matters agreement pursuant to which we are responsible for certain liabilities and obligations following the distribution. In general, under the terms of the tax matters agreement, if the distribution, together with certain related transactions, were to fail to qualify as a transaction that is generally tax-free, for U.S. federal income tax purposes, under Sections 355 and 368(a)(1)(D) of the Code, and if and to the extent that such failure results from a prohibited change of control in bluebird bio under Section 355(e) of the Code or an acquisition of bluebird bio stock or assets or certain actions, omissions or failures to act, by bluebird bio, then bluebird bio will bear any resulting taxes, interest, penalties and other costs. If and to the extent that such failure results from a prohibited change of control in 2seventy bio under Section 355(e) of the Code or an acquisition of our stock or assets or certain actions by us, then we will indemnify bluebird bio for any resulting taxes, interest, penalties and other costs, including any reductions in bluebird bio's net operating loss carryforwards or other tax assets. If such failure does not result from a prohibited change of control in bluebird bio or 2seventy bio under Section 355(e) of the Code and both we and bluebird bio are responsible for such failure, liability will be shared according to relative fault. If neither we nor bluebird bio is responsible for such failure, bluebird bio will bear any resulting taxes, interest, penalties and other costs. Our indemnification obligations to bluebird bio under the tax matters agreement are not expected to be limited in amount or subject to any cap. If we are required to pay any taxes or indemnify bluebird bio and its subsidiaries and their respective officers and directors under the circumstances set forth in the tax matters agreement, we may be subject to substantial liabilities.
 In connection with the separation, we assumed and agreed to indemnify bluebird bio for certain liabilities. If we are required to make payments pursuant to these indemnities to bluebird bio, we may need to divert cash to meet those obligations and our financial results could be harmed.

 Pursuant to the separation agreement and certain other agreements we entered into with bluebird bio, we assumed and agreed to indemnify bluebird bio for certain liabilities for uncapped amounts, which may include, among other items, associated defense costs, settlement amounts and judgments, as discussed further in "Certain Relationships and Related Person Transactions—Agreements with bluebird bio" and "Index to Financial Statements—Audited Consolidated Financial Statements—Notes to Consolidated Financial Statements." Payments pursuant to these indemnities may be significant and could harm our business, particularly indemnities relating to our actions that could impact the tax-free nature of the distribution and certain related transactions. Third parties could also seek to hold us responsible for any of the liabilities of the bluebird bio business. bluebird bio has agreed to indemnify us for liabilities of the bluebird bio business, but such indemnity from bluebird bio may not be sufficient to protect us against the full amount of such liabilities, and bluebird bio may not fully satisfy its indemnification obligations. Moreover, even if we ultimately succeed in recovering from bluebird bio any amounts for which we are held liable, we may be temporarily required to bear these losses ourselves. Each of these risks could harm our business, prospects, financial condition and results of operations.
 General risks
 Changes in tax law could adversely affect our business and financial condition.
 The rules dealing with U.S. federal, state, and local income taxation are constantly under review by persons involved in the legislative process and by the Internal Revenue Service and the U.S. Treasury Department. Changes to tax laws (which changes may have retroactive application) could adversely affect us or holders of our common stock. In recent years, many such changes have been made and changes are likely to continue to occur in the future. Future changes in tax laws could have a material adverse effect on our business, cash flow, financial condition or results of operations. It cannot be predicted whether, when, in what form, or with what effective dates, new tax laws may be enacted, or regulations and rulings may be enacted, promulgated or issued under existing or new tax laws, which could result in an increase in our or our stockholders' tax liability or require changes in the manner in which we operate in order to minimize or mitigate any adverse effects of changes in tax law or in the interpretation thereof. We urge investors to consult with their legal and tax advisers regarding the implications of potential changes in tax laws on an investment in our common stock.
 If the estimates we make, or the assumptions on which we rely, in preparing our consolidated financial statements are incorrect, our actual results may vary from those reflected in our projections and accruals.
 Our consolidated financial statements have been prepared in accordance with accounting principles generally accepted in the United States of America, or GAAP. The preparation of these consolidated financial statements requires us to make estimates and judgments that affect the reported amounts of our assets, liabilities, revenues and expenses, and related disclosure of contingent assets and liabilities. We base our estimates on historical experience and on various other assumptions that we believe to be reasonable under the circumstances. We cannot assure you, however, that our estimates, or the assumptions underlying them, will be correct.
 Further, from time to time we issue financial guidance relating to our expectations for our cash, cash equivalents, and marketable securities available for operations, which guidance is based on estimates and the judgment of management. If, for any reason, our expenses differ materially from our guidance or we utilize our cash more quickly than anticipated, we may have to adjust our publicly announced financial guidance. If we fail to meet, or if we are required to change or update any element of, our publicly disclosed financial guidance or other expectations about our business, our stock price could decline.
 Disruptions at the FDA and other government agencies caused by funding shortages or global health concerns could hinder their ability to hire, retain or deploy key personnel, and substantial leadership, personnel, and policy changes or otherwise, could prevent new or modified products from being developed, approved, or commercialized in a timely manner or at all, which could negatively impact our business.
 The ability of the FDA to review and approve new products can be affected by a variety of factors, including government budget and funding levels, statutory, regulatory, and policy changes, the FDA's ability to hire and retain key personnel and accept the payment of user fees, and other events that may otherwise affect the FDA's ability to perform routine functions. Average review times at the agency have fluctuated in recent years as a result. In

 addition, government funding of other government agencies that fund research and development activities is subject to the political process, which is inherently fluid and unpredictable. Disruptions at the FDA and other agencies, including substantial leadership, personnel, and policy changes, may also slow the time necessary for biological products or modifications to approved biological products to be reviewed and/or approved by necessary government agencies, which would adversely affect our business. For example, over the last several years, including for 35 days beginning on December 22, 2018, the U.S. government has shut down several times and certain regulatory agencies, such as the FDA, have had to furlough critical FDA employees and stop critical activities. Without appropriation of additional funding to federal agencies, our business operations related to our product development activities for the U.S. market could be impacted.

 Item 1B. Unresolved Staff Comments
 None.

 Item 1C. Cybersecurity
 Risk Management and Strategy
 We have established processes to assess risks from cybersecurity threats, monitor our information systems for potential vulnerabilities, and test those systems pursuant to our cybersecurity policies, processes, and practices, which are integrated into our overall risk management program. In an effort to protect our information systems from cybersecurity threats, we have implemented information security and incident response policies as well as operating procedures. We also use various security tools that are designed to help us identify risks from cybersecurity threats, and escalate, investigate, resolve, and recover from cybersecurity incidents in a timely manner. We have an informal risk oversight committee, which is comprised of representatives from our information technology and legal functions, in consultation with business operations, as needed. The committee assesses risks based on probability and potential impact to key business systems and processes. We have established a process for risks that are considered high, including risks from cybersecurity threats, to be incorporated into our overall risk management program and tracked as part of our overall risk management program overseen by the Audit Committee of our board of directors.
 We also collaborate with third parties to assess the effectiveness of our cybersecurity prevention and response systems and processes. These third parties include cybersecurity assessors, consultants, and other external cybersecurity experts to assist in the identification, verification, and validation of cybersecurity risks, as well as to support associated mitigation plans when necessary. We leverage these third parties to provide virtual chief information security officer and, if necessary, cybersecurity incident response services as well as to perform periodic penetration testing and other vulnerability scans. We also maintain processes designed to proactively manage potential supply chain risks posed by third-party vendors. As part of our cybersecurity risk management program, we work with certain third-party vendors to assess the their cybersecurity processes, including a process for requesting that vendors who have access to our systems and data complete cybersecurity questionnaires prior to onboarding.
 We face a number of cybersecurity risks in connection with our business. While cybersecurity threats, including those resulting from any previous cybersecurity incidents, have not materially affected, and we do not believe they are reasonably likely to materially affect, our Company, including our business strategy, results of operations, or financial condition, to date, we have, like other companies in our industry, from time to time, experienced threats and cybersecurity incidents relating to our, and our third-party vendors', data and information systems. Refer to the risk factor captioned "Our computer systems, or those of our third-party collaborators, service providers, contractors or consultants, may fail or suffer cybersecurity incidents or data breaches, which could result in a disruption of our product candidates' development programs and have a material effect on our reputation, business, financial condition or results of operations" in Part I, Item 1A. "Risk Factors" for additional description of cybersecurity risks and potential related impacts on our Company.
 Governance

 Our board of directors oversees our risk management process, including as it pertains to cybersecurity risks, directly and through its committees. The Audit Committee of the board oversees our risk management program, which focuses on the significant identified risks. Audit Committee meetings include discussions of specific risk areas throughout the year, including, among others, those relating to cybersecurity threats, as appropriate. The Audit Committee reviews our cybersecurity risk profile with management on a periodic basis, including reviewing assessments of our cybersecurity program and strategy for the prevention, detection, mitigation, and remediation of cybersecurity incidents.
 We take a risk-based approach to cybersecurity and have implemented cybersecurity policies throughout our operations that are designed to address cybersecurity threats and incidents. The Company's Senior Engineer, Information Systems is responsible for the establishment and maintenance of our cybersecurity program, as well as the assessment and management of cybersecurity risks. The Senior Engineer, Information Systems meets periodically with the Company's leadership team to discuss the status of the Company's cybersecurity program and relevant updates, as appropriate. The Senior Engineer, Information Systems is directly responsible for day-to-day cybersecurity program and security operations. The Senior Engineer, Information Systems provides periodic updates on our cybersecurity risk profile to the Audit Committee of our board of directors.

 Item 2. Properties
 Below is a summary of our material owned and leased properties as of December 31, 2024:
 Massachusetts
 Our corporate headquarters is located at 60 Binney Street, Cambridge, Massachusetts where we occupy approximately 253,108 rentable square feet of office and laboratory space under a lease that was assigned to us by bluebird bio in October 2021 and will continue until March 31, 2034, unless terminated sooner. We have the option to extend the 60 Binney Street lease for two successive five-year terms.
 Washington
 We lease office and laboratory space at 188 East Blaine Street Suite 300, Seattle, Washington, totaling approximately 58,314 square feet. The lease was assigned to us by bluebird bio in October 2021 and will continue through April 2028. We have the option to extend the lease for one five-year term.
 We believe that our existing facilities are adequate for our current needs.
 In connection with the Regeneron Transaction, Regeneron subleased our facilities in Seattle, Washington, and a portion of our facilities in Cambridge, Massachusetts.

 Item 3. Legal Proceedings
 From time to time, we may become involved in litigation or other legal proceedings. We are not currently a party to any litigation or legal proceedings that, in the opinion of our management, are probable to have a material adverse effect on our business. Regardless of outcome, litigation can have an adverse impact on our business, financial condition, results of operations and prospects because of defense and settlement costs, diversion of management resources and other factors.

 Item 4. Mine Safety Disclosures
 Not applicable.

 Item 5. Market for Registrant's Common Equity, Related Stockholder Matters and Issuer Purchases of Equity Securities
 Our common stock trades under the symbol "TSVT" on The Nasdaq Global Market and has been publicly traded since November 5, 2021. Prior to this time, there was no public market for our common stock.

 Holders of Our Common Stock
 As of March 20, 2025 there were approximately 11 holders of record of our common stock. This number does not include beneficial owners whose shares are held by nominees in street name.
 Dividend Policy
 We have never declared or paid cash dividends on our capital stock. We currently intend to retain all available funds and any future earnings, if any, to fund the development and expansion of Abecma and we do not anticipate paying any cash dividends in the foreseeable future. Any future determination to pay dividends will be made at the discretion of our board of directors and will depend on various factors, including applicable laws, our results of operations, financial condition, future prospects and any other factors deemed relevant by our board of directors.
 Securities Authorized for Issuance Under Equity Compensation Plans
 The information required by Item 5 of Form 10-K regarding equity compensation plans is incorporated herein by reference to Item 12 of Part III of this Annual Report on Form 10-K.
 Recent Sales of Unregistered Equity Securities
 None.
 Purchases of Equity Securities by the Issuer and Affiliated Purchasers
 We did not purchase any of our registered equity securities during the period covered by this Annual Report on Form 10-K.

 Item 6. Reserved
 Not applicable.

 Item 7. Management's Discussion and Analysis of Financial Condition and Results of Operations
 You should read the following discussion and analysis of our financial condition and results of operations together with our financial statements and related notes appearing elsewhere in this Annual Report. Some of the information contained in this discussion and analysis or set forth elsewhere in this Annual Report, including information with respect to our plans and strategy for our business and related financing, includes forward-looking statements that involve risks and uncertainties. As a result of many factors, including those factors set forth in the section entitled "Risk Factors," our actual results could differ materially from the results described in or implied by the forward-looking statements contained in the following discussion and analysis. You should carefully read the section entitled "Risk Factors" to gain an understanding of the important factors that could cause actual results to differ materially from our forward-looking statements. Please also see the section entitled "Special Note Regarding Forward-Looking Statements." We do not assume any obligation to update any forward-looking statements, whether as a result of new information, future events or otherwise, except as required by law.

 Overview
 We are a cell therapy company focused on the research, development, and commercialization of transformative treatments for cancer. We were incorporated in Delaware in April 2021 and are led by an accomplished team with significant expertise and experience in this field. In January 2024, we announced a strategic realignment to focus exclusively on the development and commercialization of idecabtagene vicleucel (ide-cel, marketed in the United States as Abecma). We, together with our partner BMS, are delivering Abecma to multiple myeloma patients in the United States following approval by the FDA of Abecma in March 2021 for the treatment of adults with multiple myeloma who have received at least four prior lines of therapy, including an immunomodulatory agent, a proteasome inhibitor and an anti-CD38 monoclonal antibody. On April 4, 2024 the FDA approved Abecma for the treatment of adult patients with relapsed or refractory multiple myeloma after two or more prior lines of therapy, including an immunomodulatory agent, a proteasome inhibitor, and an anti-CD38 monoclonal antibody. On September 25, 2024, following a joint decision we made with BMS earlier that week, we announced the discontinuation of enrollment in our ongoing Phase 3 KarMMa-9 study evaluating Abecma with lenalidomide maintenance versus lenalidomide maintenance alone in patients with newly diagnosed multiple myeloma who have suboptimal response to autologous stem cell transplant.
 Upon closing the Regeneron Transaction on April 1, 2024, Regeneron assumed all of the ongoing program infrastructure and personnel costs related to our solid tumor and other oncology and autoimmune cell therapy programs, including the bbT369 program in B-NHL, SC-DARIC33 in AML, MUC16 in ovarian cancer, MAGE-A4, autoimmune, and several unnamed targets. In June 2024, we announced the completion of an asset purchase agreement with Novo as part of our strategic realignment. Under the terms of the Novo Transaction, Novo acquired the Company's program for the research, development, manufacture, regulatory approval, and commercialization of gene therapy products exploiting the megaTAL Platform that is directed to the treatment, diagnosis and prevention of hemophilia (the "megaTAL Sale").
 We have never been profitable and have incurred net losses since inception. Our net losses for the years ended December 31, 2024 and 2023 were $57.2 million and $217.6 million, respectively. We expect to continue to generate operating losses and negative operating cash flows for the near future.
 We expect to incur significant expenses as we continue to (i) educate physicians on treatment sequencing and the emerging data supporting the use of BCMA-directed CAR Ts before other BCMA-targeted therapies, (ii) competitively differentiate Abecma's real-world safety, efficacy and product reliability and predictability profile and, (iii) continue to support the quality control of LVV. Accordingly, until we generate significant revenues from product sales, we may continue to seek to fund our operations through public or private equity or debt financings, strategic collaborations, or other sources. If we use our capital resources sooner than expected, we would evaluate further reductions in our expense or obtaining additional financing. However, we may be unable to raise additional funds or enter into such other arrangements when needed on favorable terms or at all. Our failure to raise capital or enter into such other arrangements as and when needed would have a negative impact on our financial condition and

 our ability to develop and commercialize Abecma. Refer to sections Liquidity and Capital Resources and Funding Requirements below for further discussion.
 The Proposed BMS Transaction
 On March 10, 2025, we entered into the BMS Merger Agreement, pursuant to which, and upon the terms and subject to the conditions thereof, a wholly-owned subsidiary of BMS will commence a tender offer to purchase all of our outstanding common stock at a cash price of $5.00 per share, less any applicable withholding taxes and without interest. In the event the tender offer conditions are satisfied and the tender offer is closed, the parties will consummate a merger that will result in our company being a wholly owned subsidiary of BMS. Upon completion of the merger, we will no longer be a publicly traded company, and the listing of our common stock on Nasdaq will have been terminated. Refer to Note 20 to our Consolidated Financial Statements regarding the BMS Merger Agreement, the transactions provided for thereunder, and the various conditions to closing the transaction. Refer to Item 1A. "Risk Factors" for a summary of risks related to the transaction.

 Critical Accounting Policies and Significant Judgments and Estimates
 Our management's discussion and analysis of our financial condition and results of operations are based on our consolidated financial statements, which have been prepared in accordance with generally accepted accounting principles in the United States. The preparation of these financial statements requires us to make estimates and judgments that affect the reported amounts of assets, liabilities, and expenses and the disclosure of contingent assets and liabilities in our financial statements. Estimates and judgments are used in the following areas, among others: future undiscounted cash flows and subsequent fair value estimates used to assess potential and measure any impairment of long-lived assets, including intangible assets, the measurement of right-of-use assets, sales forecasts and corresponding expiry dates utilized to determine our contingent liabilities for obsolete and excess inventory reserves under our collaboration with BMS, contingent consideration, stock-based compensation expense, accrued expenses, income taxes, and the assessment of our ability to fund operations for at least the next twelve months from the date of issuance of our financial statements. On an ongoing basis, we evaluate our estimates and judgments, including expected business and operational changes, sensitivity and volatility associated with the assumptions used in developing estimates, and whether historical trends are expected to be representative of future trends. We base our estimates on historical experience, known trends and events and various other factors that are believed to be reasonable under the circumstances, the results of which form the basis for making judgments about the carrying values of assets and liabilities that are not readily apparent from other sources. Actual results may differ from these estimates under different assumptions or conditions. In making estimates and judgments, management employs critical accounting policies.
 While our significant accounting policies are described in more detail in the notes to our audited consolidated financial statements, we believe the following accounting policies to be most critical to the judgments and estimates used in the preparation of our financial statements.

 Revenue Recognition
 Revenue Recognition
 Under Topic 606, Revenue from Contracts with Customers, an entity recognizes revenue when its customer obtains control of promised goods or services, in an amount that reflects the consideration that the entity expects to receive in exchange for those goods or services. To determine revenue recognition for arrangements that an entity determines are within the scope of Topic 606, the entity performs the following five steps: (i) identify the contract(s) with a customer; (ii) identify the performance obligations in the contract; (iii) determine the transaction price, including variable consideration, if any; (iv) allocate the transaction price to the performance obligations in the contract; and (v) recognize revenue when (or as) the entity satisfies a performance obligation. We only apply the five-step model to contracts when it is probable that the entity will collect the consideration to which it is entitled in exchange for the goods or services it transfers to the customer.
 Once a contract is determined to be within the scope of Topic 606, we assess the goods or services promised within each contract and determine those that are performance obligations. Arrangements that include rights to

 additional goods or services that are exercisable at a customer's discretion are generally considered options. We assess if these options provide a material right to the customer and if so, they are considered performance obligations. The identification of material rights requires judgments related to the determination of the value of the underlying license relative to the option exercise price, including assumptions about technical feasibility and the probability of developing a candidate that would be subject to the option rights. The exercise of a material right is accounted for as a contract modification for accounting purposes.
 We assess whether each promised good or service is distinct for the purpose of identifying the performance obligations in the contract. This assessment involves subjective determinations and requires management to make judgments about the individual promised goods or services and whether such are separable from the other aspects of the contractual relationship. Promised goods and services are considered distinct provided that: (i) the customer can benefit from the good or service either on its own or together with other resources that are readily available to the customer (that is, the good or service is capable of being distinct) and (ii) the entity's promise to transfer the good or service to the customer is separately identifiable from other promises in the contract (that is, the promise to transfer the good or service is distinct within the context of the contract). In assessing whether a promised good or service is distinct, we consider factors such as the license terms, the research, manufacturing and commercialization capabilities of the collaboration partner and the availability of the associated expertise in the general marketplace. We also consider the intended benefit of the contract in assessing whether a promised good or service is separately identifiable from other promises in the contract. If a promised good or service is not distinct, an entity is required to combine that good or service with other promised goods or services until it identifies a bundle of goods or services that is distinct.
 The transaction price is determined and allocated to the identified performance obligations in proportion to their stand-alone selling prices, or SSP, on a relative SSP basis. SSP is determined at contract inception and is not updated to reflect changes between contract inception and when the performance obligations are satisfied. Determining the SSP for performance obligations requires significant judgment. In developing the SSP for a performance obligation, we consider applicable market conditions and relevant entity-specific factors, including factors that were contemplated in negotiating the agreement with the customer and estimated costs. We validate the SSP for performance obligations by evaluating whether changes in the key assumptions used to determine the SSP will have a significant effect on the allocation of arrangement consideration between multiple performance obligations.
 If the consideration promised in a contract includes a variable amount, we estimate the amount of consideration to which we will be entitled in exchange for transferring the promised goods or services to a customer. We determine the amount of variable consideration by using the expected value method or the most likely amount method. The amount of variable consideration included in the transaction price is constrained to the amount for which it is probable that a significant reversal of cumulative revenue recognized will not occur when the uncertainty related to the variable consideration is resolved. At the end of each subsequent reporting period, we re-evaluate the estimated variable consideration included in the transaction price and any related constraint, and if necessary, adjust our estimate of the overall transaction price. Any such adjustments are recorded on a cumulative catch-up basis in the period of adjustment.
 If an arrangement includes development and regulatory milestone payments, we evaluate whether the milestones are considered probable of being reached and estimate the amount to be included in the transaction price using the most likely amount method. If it is probable that a significant revenue reversal would not occur, the associated milestone value is included in the transaction price. Milestone payments that are not within our control or the licensee's control, such as regulatory approvals, are generally not considered probable of being achieved until those approvals are received.
 For arrangements with licenses of intellectual property that include sales-based royalties, including milestone payments based on the level of sales, and the license is deemed to be the predominant item to which the royalties relate, we recognize royalty revenue and sales-based milestones at the later of (i) when the related sales occur, or (ii) when the performance obligation to which the royalty has been allocated has been satisfied.
 In determining the transaction price, we adjust consideration for the effects of the time value of money if the timing of payments provides us with a significant benefit of financing. We do not assess whether a contract has a

 significant financing component if the expectation at contract inception is such that the period between payment by the licensees and the transfer of the promised goods or services to the licensees will be one year or less. We assessed each of our revenue generating arrangements in order to determine whether a significant financing component exists and concluded that a significant financing component does not exist in any of our arrangements.
 We recognize as revenue the amount of the transaction price that is allocated to the respective performance obligation when (or as) each performance obligation is satisfied, either at a point in time or over time, and if over time recognition is based on the use of an output or input method.
 We recognize revenue within the following financial statement captions:
 Service Revenue
 To date, our service revenue has primarily been generated from the elements of the collaboration arrangements with BMS and Novo that are accounted for pursuant to Topic 606, using the five-step model described above. We analyze our collaboration arrangements to assess whether they are within the scope of ASC 808 or Topic 606. For the elements of the arrangement which are more reflective of a vendor-customer relationship and therefore within the scope of Topic 606, we record the related revenue as service revenue on the consolidated statements of operations and comprehensive loss. Refer to Financial Operations Overview – Revenue below for service revenue results for the years ended December 31, 2024 and 2023.
 Collaborative Arrangement Revenue and Share of Collaboration Loss
 We analyze our collaboration arrangements to assess whether they are within the scope of ASC 808, Collaborative Arrangements, ("ASC 808"), which includes determining whether such arrangements involve joint operating activities performed by parties that are both active participants in the activities and exposed to significant risks and rewards dependent on the commercial success of such activities. This assessment is performed throughout the life of the arrangement based on changes in the responsibilities of all parties in the arrangement. For collaboration arrangements within the scope of ASC 808 that contain multiple elements, we first determine which elements of the collaboration are deemed to be within the scope of ASC 808 and those that are more reflective of a vendor-customer relationship and therefore within the scope of ASC 606, Revenue from Contracts with Customers, ("Topic 606" or "ASC 606"). For those elements of the arrangement that are accounted for pursuant to Topic 606, we apply the five-step model prescribed in Topic 606. For elements of collaboration arrangements that are accounted for pursuant to ASC 808, an appropriate recognition method is determined and applied consistently, generally by analogy to Topic 606. In arrangements where we do not deem our collaborator to be our customer, payments to and from our collaborator are presented in the consolidated statements of operations and comprehensive loss based on the nature of the payments, as summarized in the table and further described below. The calculation of collaborative activity to be recognized is performed on a quarterly basis and is independent of previous quarterly activity. This may result in fluctuations between revenue and expense recognition period over period, depending on the varying extent of effort performed by each party during the period.

 Nature of Payment
 Statement of Operations Presentation

 Our share of net profits in connection with commercialization of products

 Our share of net losses in connection with commercialization of products
 Share of collaboration loss

 Net reimbursement to us for research and development expenses

 Net reimbursement to the collaborator for research and development
 Research and development expense

 Where the collaborator is the principal in the product sales, we recognize our share of any profits or losses, representing net product sales less cost of goods sold and shared commercial and other expenses, along with reimbursement by BMS of commercial costs incurred us, in the period in which such underlying sales occur and costs are incurred by the collaborator.
 To date, collaborative arrangement revenue has been primarily generated from the collaboration arrangements with BMS and Regeneron, as further described in Note 11, Collaborative arrangements and strategic partnerships,

 in the notes to our audited consolidated financial statements. Refer to Financial Operations Overview – Revenue below for collaborative arrangement revenue results for the years ended December 31, 2024 and 2023.
 The recognition of service revenue, collaborative arrangement revenue, and share of collaboration loss require management judgment due to the fact that the terms of our collaboration arrangements are complicated and the nature of the collaborative activities change over time. This process includes the identification of costs that we incur that relate to each particular collaboration arrangement, evaluating the nature of these costs (for example, whether the costs relate to a particular geography or territory or whether the costs relate to clinical or commercial activities), and applying the terms of the respective collaborative arrangement to determine the portion of such costs that are the responsibility of the collaboration partner, which in certain circumstances requires significant judgment.
 Accrued Research and Development Expenses
 As part of the process of preparing our financial statements, we are required to estimate our accrued expenses. This process involves reviewing open contracts and purchase orders, communicating with our personnel to identify services that have been performed on our behalf and estimating the level of service performed and the associated cost incurred for the service when we have not yet been invoiced or otherwise notified of the actual cost. The majority of our service providers invoice us monthly in arrears for services performed or when contractual milestones are met. We make estimates of our accrued expenses as of each balance sheet date in our financial statements based on facts and circumstances known to us at that time.
 We recognize expenses related to clinical studies based on our estimates of the services received and efforts expended pursuant to contracts with multiple CROs that conduct and manage clinical studies on our behalf. The financial terms of these agreements are subject to negotiation, vary from contract to contract and may result in uneven payment flows. There may be instances in which payments made to our vendors will exceed the level of services provided and result in a prepayment of the clinical expense. Payments under some of these contracts depend on factors such as the successful enrollment of subjects and the completion of clinical study milestones. In accruing service fees, we estimate the time period over which services will be performed and the level of effort to be expended in each period and adjust accordingly.
 Other examples of estimated accrued research and development expenses include fees paid to:
 • collaboration partners for research performed in connection with ongoing collaboration arrangements;
 • investigative sites in connection with clinical studies;
 • vendors in connection with preclinical development activities; and
 • vendors related to the development, manufacturing, and distribution of clinical trial materials.
 Following the closing of the Novo Transaction and Regeneron Transaction, research and development expenses consist primarily of costs incurred for the development of Abecma in collaboration with BMS. Historical research and development expenses included costs for Abecma, as well as costs incurred for the development of product candidates that were sold to Regeneron and Novo in the second quarter of 2024.
 Our share-based compensation expense relates to stock options, restricted stock units, restricted stock awards, and shares issued under our employee stock purchase plan. Grants are awarded to employees and non-employees, including our board of directors.
 We account for our stock-based compensation awards in accordance with FASB ASC Topic 718, Compensation—Stock Compensation, or ASC 718. ASC 718 requires all stock-based payments, including grants of stock options and restricted stock units and modifications to existing stock options, to be recognized in the consolidated statements of operations and comprehensive loss based on their fair values.

 Our stock-based awards are subject to either service, performance-based, or market-based vesting conditions. Compensation expense related to awards with service-based vesting conditions is recognized on a straight-line basis based on the grant date fair value over the associated service period of the award, which is generally the vesting term. Compensation expense related to awards with performance-based vesting conditions is recognized based on the grant date fair value over the requisite service period using the accelerated attribution method to the extent achievement of the performance condition is probable.
 We estimate the fair value of our option awards using the Black-Scholes option pricing model, which requires the input of subjective assumptions, including (i) the expected stock price volatility, (ii) the calculation of expected term of the award, (iii) the risk-free interest rate, and (iv) expected dividends. Due to the lack of company specific historical and implied volatility data, we based our estimate of expected volatility on the estimate and expected volatilities of a representative group of publicly traded companies. For these analyses, we select companies with comparable characteristics to ours including enterprise value, risk profiles, position within the industry, and with historical share price information sufficient to meet the expected life of the stock-based awards. We will continue to apply this process until a sufficient amount of historical information regarding the volatility of our own stock price becomes available. For awards granted subsequent to the separation from bluebird bio, we have estimated the expected term of our employee stock options using the "simplified" method, whereby, the expected term equals the arithmetic average of the vesting term and the original contractual term of the option due to its lack of sufficient historical data. For stock options that were converted in accordance with the Employee Matters Agreement, as discussed above and as further described in Note 14, Stock-based compensation, to the consolidated financial statements included elsewhere in this Annual Report on Form 10-K, we have estimated the expected term to be the remaining contractual term of the awards as of the date of the separation. The risk-free interest rates for periods within the expected term of the option are based on the U.S. Treasury securities with a maturity date commensurate with the expected term of the associated award. We have never paid, and do not expect to pay, dividends in the foreseeable future.
 For performance-based restricted stock units that vest based on a total shareholder return metric, the vesting condition is considered a market condition as it vests based on the movement in share price of a company. The impact of the market condition is reflected in the award's fair value on the grant date, and the expense is recognized irrespective of whether the market condition is achieved as long as the required service is provided.
 We account for forfeitures as they occur. Stock-based compensation expense recognized in the financial statements is based on awards for which performance or service conditions are expected to be satisfied.
 Recently Issued Accounting Pronouncements
 See Note 2, Summary of significant accounting policies and basis of presentation, in the notes to the audited consolidated financial statements included elsewhere in this Annual Report on Form 10-K for a description of recent accounting pronouncements applicable to our business.

 Financial Operations Overview
 Revenue
 Our revenues have been derived from collaboration arrangements and out-licensing arrangements, related to our collaboration arrangement with BMS as part of which we are jointly commercializing Abecma in the United States and our collaboration arrangement with Regeneron. To date, all revenue we have recognized relating to the sale of products has been the collaboration revenue derived from commercial sales of Abecma by BMS, and we have not recognized any revenue from the sale of products by us.
 For the years ended December 31, 2024 and 2023 service revenue consisted of the following (in thousands):

 2024
 2023

 ide-cel ex-U.S. service revenue from BMS
 $
 10,611
 $
 14,751

 Service revenue from December 2021 agreement with Novo

 3,507
 5,765

 Other
 4,000
 3,628

 Total service revenue
 $
 18,118
 $
 24,144

 For the years ended December 31, 2024 and 2023 collaborative arrangement revenue consisted of the following (in thousands):

 2024
 2023

 U.S. Abecma collaboration with BMS
 $
 $

 Collaboration with Regeneron
 4,696
 21,591

 Total collaborative arrangement revenue
 $
 19,744
 $
 71,601

 To date, Abecma is our only commercial product where the collaborator is the principal in the product sales and thus, all amounts shown within our consolidated statements of operations and comprehensive loss for share of collaboration loss relate to Abecma. The tables below summarize the impact of the Abecma U.S. collaboration profit (loss) share on our consolidated statements of operations and comprehensive loss for the years ended December 31, 2024 and 2023 (in thousands). Note that these tables do not include research and development costs for Abecma shared between us and BMS - refer to Note 11, Collaborative arrangements and strategic partnerships, in the notes to the consolidated financial statements for information on Abecma research and development costs.

 Abecma U.S. Collaboration Profit (Loss) Share
 March 31, 2024
 June 30, 2024
 September 30, 2024

 Our share of profits (losses), net of our share of BMS costs for commercial activities
 $
 (1,975)
 $
 3,549
 $
 9,617
 $
 (4,494)
 $
 6,697

 Reimbursement from BMS for our costs of commercial manufacturing and commercial activities
 1,067
 1,171
 3,798

 Collaborative arrangement revenue (1)

 $
 —
 $
 4,364
 $
 10,684
 $
 —
 $

 Share of collaboration loss (1)

 $
 (1,230)
 $
 —
 $
 —
 $
 (3,323)
 $
 (4,553)

 Costs of commercial manufacturing incurred by us, prior to BMS reimbursement
 (1,428)
 (1,141)
 (1,567)
 (1,309)
 (5,445)

 Costs of commercial activities incurred by us, prior to BMS reimbursement
 (63)
 —
 (83)
 (89)
 (235)

 Total impact of Abecma U.S. collaboration profit (loss) on our statements of operations and comprehensive income (loss)
 $
 (2,721)
 $
 3,223
 $
 9,034
 $
 (4,721)
 $
 4,815

 Abecma U.S. Collaboration Profit (Loss) Share
 March 31, 2023
 June 30, 2023
 September 30, 2023

 Our share of profits (losses), net of our share of BMS costs for commercial activities
 $
 21,581
 $
 23,272
 $
 (582)
 $
 1,366
 $
 45,637

 Reimbursement from BMS for our costs of commercial manufacturing and commercial activities
 1,380
 1,271
 1,118
 4,373

 Collaborative arrangement revenue (1)

 $
 22,961
 $
 24,543
 $
 $
 1,970
 $

 Share of collaboration loss (1)

 $
 —
 $
 —
 $
 —
 $
 —
 $
 —

 Costs of commercial manufacturing incurred by us, prior to BMS reimbursement
 (2,583)
 (2,389)
 (2,167)
 (1,136)
 (8,275)

 Costs of commercial activities incurred by us, prior to BMS reimbursement
 (176)
 (153)
 (70)
 (73)
 (472)

 Total impact of Abecma U.S. collaboration profit (loss) on our statements of operations and comprehensive loss
 $
 20,202
 $
 22,001
 $
 (1,701)
 $
 $
 41,263

 (1) This calculation is performed on a quarterly basis and consists of our share of profits, net of our share of BMS costs for commercial activities, offset by reimbursement from BMS for our commercial activities. The calculation is independent of previous activity, which may result in fluctuations between revenue and expense recognition period over period. Collaborative arrangement revenue net of share of collaboration loss was $10.5 million and $50.0 million, for the years ended December 31, 2024 and 2023, respectively.

 Nonrefundable license fees are recognized as revenue upon delivery of the license provided there are no unsatisfied performance obligations in the arrangement. License revenue has historically been generated from out-license agreements, under which we may also recognize revenue from potential future milestone payments and royalties.
 For arrangements with licenses of intellectual property that include sales-based royalties, including milestone payments based on the level of sales, and the license is deemed to be the predominant item to which the royalties relate, we recognize revenue at the later of (i) when the related sales occur, or (ii) when the performance obligation to which the royalty has been allocated has been satisfied.
 Research and Development Expenses
 Following the closing of the Novo Transaction and Regeneron Transaction, research and development expenses consist primarily of costs incurred for the development of Abecma in collaboration with BMS. This includes costs associated with the following clinical studies:
 • KarMMa study – an open label, single-arm, multi-center phase 2 study to examine the efficacy and safety of ide-cel in the treatment of patients with relapsed and refractory multiple myeloma. The costs incurred by BMS for this study are subject to the cost-sharing provisions of our BMS collaboration arrangement.
 • KarMMa-2 study – a multi-cohort, open-label, multicenter phase 2 study to examine the safety and efficacy of ide-cel in the treatment of patients with relapsed and refractory multiple myeloma and in high-risk multiple myeloma. The costs incurred by BMS for this study are subject to the cost-sharing provisions of our BMS collaboration arrangement.
 • KarMMa-3 study – a multicenter, randomized, open-label phase 3 study comparing the efficacy and safety of ide-cel versus standard triplet regimens in patients with relapsed and refractory multiple myeloma. The costs incurred by BMS for this study are subject to the cost-sharing provisions of our BMS collaboration arrangement.
 • KarMMa-9 study – a multicenter, randomized, open-label phase 3 study comparing the efficacy and safety of ide-cel with Lenalidomide maintenance versus Lenalidomide maintenance therapy alone in adult participants with newly diagnosed multiple myeloma who have suboptimal response after autologous stem

 cell transplantation. The costs incurred by BMS for this study are subject to the cost-sharing provisions of our BMS collaboration arrangement. In September 2024, we and BMS decided to discontinue enrollment in our ongoing Phase 3 KarMMa-9 study.
 Historical research and development expenses included costs for Abecma, as discussed above, as well as costs incurred for the development of product candidates that were sold to Regeneron and Novo in the second quarter of 2024. Information about the historical costs we incurred on these programs can be found in our previous Form 10-Q and Form 10-K filings.
 Research and development costs are expensed as incurred. Costs for certain development activities are recognized based on an evaluation of the progress to completion of specific tasks using information and data provided by vendors and clinical sites. We cannot determine with certainty the duration and completion costs of the current or future clinical studies of Abecma. The duration, costs and timing associated with the development of Abecma depend on a variety of factors including:
 • the scope, rate of progress, and expense of our ongoing clinical studies and other research and development activities we undertake;
 • future clinical study results;
 • uncertainties in clinical study enrollment rates and long-term follow up costs;
 • new manufacturing processes or protocols that we may choose to or be required to implement in the manufacture of our lentiviral vector or drug product;
 • regulatory feedback on requirements for regulatory approval, as well as changing standards for regulatory approval; and
 • the timing and receipt of any regulatory approvals.
 Cost of Manufacturing for Commercial Collaboration
 Cost of manufacturing for commercial collaboration consists of quality and other manufacturing costs incurred by us to support the manufacture of Abecma inventory sold by our collaborative partner, BMS, in both the U.S. and ex-U.S. regions. These costs are subject to the cost sharing arrangement under the terms of our collaboration agreement (the Amended Ide-cel CCPS) with BMS. For further information on the Amended Ide-cel CCPS, please refer to Note 11, Collaborative arrangements and strategic partnerships, in the notes to our audited consolidated financial statements.
 The reimbursement from BMS for their share of our U.S. quality and other manufacturing costs is recorded as collaborative arrangement revenue or share of collaboration loss in our consolidated statements of operations and comprehensive loss. The reimbursement from BMS for our ex-U.S. quality and other manufacturing costs is recorded as service revenue in our consolidated statements of operations and comprehensive loss.
 In September 2023, we announced our restructuring plan, or Restructuring Plan, to conserve financial resources and better align our workforce with current business needs. As part of the Restructuring Plan, our workforce was reduced by approximately 40%. Substantially all of the reduction in personnel was completed by December 31, 2023. In connection with the Restructuring Plan, we incurred one-time costs in the third quarter of 2023 relating to severance and retention packages and related benefits. These costs were recorded as restructuring expenses in our consolidated statements of operations and comprehensive loss. This plan was complete as of June 30, 2024.
 In January 2024, we announced a strategic path forward to focus exclusively on the commercialization and development of Abecma. In connection with our strategic re-alignment, we entered into an asset purchase agreement with Regeneron to sell our oncology and autoimmune research and development programs, clinical manufacturing capabilities, and related platform technologies which closed on April 1, 2024. Approximately 62% of the workforce

 transitioned to Regeneron as a part of the sale. Additionally, as part of the strategic re-alignment, our board of directors approved the 2024 Restructuring Plan to further reduce our remaining workforce by approximately 14%. We expect the 2024 Restructuring Plan to be substantially complete during the first half of 2025, as certain transition activities related to our strategic re-alignment will extend into 2025.
 Additionally, as of December 31, 2024, we recognized expenses of $5.7 million representing our share of costs associated with BMS' early exit from a commercial manufacturing and supply agreement as a result of our transition to the use of suspension lentiviral vector in the manufacturing of Abecma. This was recorded within restructuring expenses in our consolidated statements of operations and comprehensive loss.
 Selling, General and Administrative Expenses
 Selling, general and administrative expenses consist primarily of salaries and related costs for personnel, including stock-based compensation and travel expenses for our employees in executive, operational, finance, legal, business development, commercial, information technology, and human resource functions. Other selling, general and administrative expenses include facility-related costs, insurance, IT costs, professional fees for accounting, tax, legal and consulting services, directors' fees and expenses associated with obtaining and maintaining patents.
 Share of Collaboration Loss
 Share of collaboration loss represents our share of net loss arising from product sales less cost of goods sold and shared commercial costs and other expenses related to the commercialization of a product where the collaborator is the principal in the product sales.
 Cost of Royalty and Other Revenue
 Cost of royalty and other revenue represents expenses associated with amounts owed to third-party licensors as a result of revenue recognized under our out-license arrangements.
 Change in Fair Value of Contingent Consideration
 On June 30, 2014, bluebird bio acquired Pregenen. All assets, liabilities and future obligations related to the Pregenen acquisition, including the resulting intangible assets, goodwill and contingent consideration, were assumed by us in connection with the separation. The agreement provided for up to $135.0 million in future contingent cash payments upon the achievement of certain preclinical, clinical and commercial milestones related to the Pregenen technology.
 As of December 31, 2024, there were $99.9 million in future contingent cash payments related to commercial milestones. During 2024, we determined the probability of milestone achievement to be zero and as a result reduced the fair value of contingent consideration, classified within other non-current liabilities on our consolidated balance sheet, to zero. Please refer to Note 5, Fair value measurements, for further information.
 Gain on sale to Novo
 The gain on sale to Novo consists of upfront cash consideration received for the Novo Transaction, less consideration received and deferred related to transition services, combined with the derecognition of deferred revenue remaining from the Novo Collaboration Agreement.
 Loss on assets held for sale to Regeneron
 The loss on assets held for sale to Regeneron consists of fixed assets that ceased depreciation, measured at the lower of their carrying value or fair value less cost to sell.
 Other Income, Net
 Other income, net consists primarily of rental income from a third party, income recognized under our transition service agreements with bluebird bio, and sublease income from bluebird bio, which terminated in 2023.

 Results of Operations
 The following discussion summarizes the key factors we believe are necessary for an understanding of our consolidated financial statements.
 Comparison of the years ended December 31, 2024 and 2023

 2024
 2023
 Change

 Revenue:

 Service revenue
 $
 18,118
 $
 24,144
 $
 (6,026)

 19,744
 71,601
 (51,857)

 Royalty and other revenue
 —
 4,642
 (4,642)

 Total revenues
 37,862
 100,387
 (62,525)

 Operating expenses:

 Research and development
 76,917
 230,758
 (153,841)

 Cost of manufacturing for commercial collaboration
 18,010
 14,819
 3,191

 Selling, general and administrative
 43,924
 69,414
 (25,490)

 Share of collaboration loss
 4,553
 —
 4,553

 12,303
 8,614
 3,689

 Cost of royalty and other revenue
 —
 2,099
 (2,099)

 Change in fair value of contingent consideration
 (2,415)
 (2,650)

 Goodwill impairment charge

 —
 12,056
 (12,056)

 Total operating expenses
 153,292
 337,995
 (184,703)

 Loss from operations
 (115,430)
 (237,608)
 122,178

 Interest income, net
 10,875
 12,413
 (1,538)

 Other income, net
 4,347
 7,625
 (3,278)

 Gain on sale of assets to Novo

 47,987
 —
 47,987

 Loss on assets held for sale to Regeneron
 (5,026)
 —
 (5,026)

 Loss before income taxes
 (57,247)
 (217,570)
 160,323

 Income tax expense
 —
 —
 —

 $
 (57,247)
 $
 (217,570)
 $
 160,323

 Revenue. Total revenue was $37.9 million for the year ended December 31, 2024, compared to $100.4 million for the year ended December 31, 2023. The decrease of $62.5 million was primarily attributable to a decrease in collaborative arrangement revenue recognized under our collaboration arrangement with BMS, driven by decreased Abecma sales. The decrease was also due to the termination of the Regeneron Collaboration Agreement concurrently with the close of the Regeneron Transaction, which occurred on April 1, 2024.
 Research and Development Expenses. Research and development expenses were $76.9 million for the year ended December 31, 2024, compared to $230.8 million for the year ended December 31, 2023. The overall decrease of $153.8 million was primarily attributable to the following:
 •$61.0 million of decreased employee compensation costs, primarily resulting from the Regeneron Transaction, as part of which a large portion of our research and development workforce transitioned to

 Regeneron. Additionally, there was a 40% reduction to our workforce as part of our restructuring in September 2023 and an additional reduction to our workforce initiated in January 2024;
 •$44.3 million of decreased facilities and IT costs largely due to the Regeneron Transaction, which resulted in Regeneron subleasing a significant portion of our current leased space in Cambridge and Seattle, reducing rent and associated facility costs;
 •$34.3 million of decreased material production costs primarily related to decreased manufacturing activities of suspension lentiviral vector for ide-cel development. The decrease is also attributable to decreased plasmids and cell bank manufacturing costs, which were assumed by Regeneron as part of the Regeneron Transaction beginning in the second quarter of 2024;
 •$13.7 million of decreased lab expenses and other platform costs primarily relating to a decrease in lab consumables costs which were assumed by Regeneron as part of the Regeneron Transaction beginning in the second quarter of 2024;
 •$3.6 million of decreased license and milestone fees associated with a milestone paid to Medigene in the first quarter of 2023 for the continued development of our MAGE-A4 TCR program in solid tumors, which was being developed as part of our collaboration with Regeneron;
 •$2.6 million decrease in consulting and professional service fees; and
 •$1.7 million decrease in clinical trial and medical research costs.
 These decreases were partially offset by a $7.3 million increase in net research and development expenses recognized under our collaboration with BMS.
 Cost of Manufacturing for Commercial Collaboration. Cost of manufacturing for commercial collaboration was $18.0 million for the year ended December 31, 2024, compared to $14.8 million for the year ended December 31, 2023. The increase of $3.2 million was primarily due to increased costs allocated to Abecma in the second half of 2024 upon the completion of our strategic realignment to focus on the development and commercialization of Abecma.
 Selling, General and Administrative Expenses. Selling, general and administrative expenses were $43.9 million for the year ended December 31, 2024, compared to $69.4 million for the year ended December 31, 2023. The decrease of $25.5 million was primarily due to the following:
 •$22.8 million of decreased compensation expenses primarily resulting from the 40% reduction in our workforce announced in September 2023 and the additional reduction to our workforce announced in January 2024;
 •$3.9 million decrease in costs associated with terminations and settlements related to license agreements; and
 •$3.3 million of decreased consulting and professional service fees.
 The decreases were partially offset by $5.0 million of increased facility related expenses allocated to selling, general, and administrative expense as a result of the sale of our research and development pipeline to Regeneron and Novo.
 Share of Collaboration Loss. Share of collaboration loss represents our share of net loss arising from the commercialization of Abecma under the BMS collaboration during the first and fourth quarters of 2024. The collaboration resulted in collaborative arrangement revenue during the second and third quarters of 2024.
 Restructuring Expenses. The increase in restructuring expenses is primarily due to our share of one-time costs incurred during the second and third quarters of 2024 of $5.7 million related to BMS' early exit from a commercial manufacturing and supply agreement as a result of the transition to suspension lentiviral vector for Abecma. The

 remaining increase is attributable to costs incurred related to the reduction in our workforce as a part of our 2024 Restructuring Plan, initiated in January 2024.
 Cost of Royalty and Other Revenue. There is no cost of royalty and other revenue for the year ended December 31, 2024, and total cost of royalty and other revenue was $2.1 million for the year ended December 31, 2023.
 Change in Fair Value of Contingent Consideration. The change in fair value of contingent consideration of $2.7 million was primarily due to the change in significant unobservable inputs used in the fair value measurement of contingent consideration, including the probabilities of successful achievement of clinical and commercial milestones and discount rates. As of September 30, 2024, we determined the probability of milestone achievement to be zero and as a result we reduced the fair value of the contingent consideration liability to zero.
 Goodwill Impairment Charge. During the third and fourth quarters of 2023, we experienced a sustained decline in the price of our common stock in part due to decreased external expectations for future Abecma sales resulting from increased competitive dynamics, which was considered a triggering event. We performed a goodwill impairment test that resulted in a non-cash impairment charge of $12.1 million.
 Interest Income, Net. Interest income, net was $10.9 million and $12.4 million for the twelve months ended December 31, 2024 and 2023, respectively. The decrease of $1.5 million was due to a decline in the total securities held partially offset by an increase in income earned on securities compared to the prior year.
 Gain on sale to Novo. In June 2024, we announced the completion of an asset purchase agreement with Novo. Refer to Note 3, Asset purchase agreements, in the notes to the consolidated financial statements for further detail regarding the gain on sale related to this transaction.
 Loss on assets held for sale to Regeneron. The loss on assets held for sale consists of fixed assets that ceased depreciation, measured at the lower of their carrying value or fair value less cost to sell. Refer to Note 3, Asset purchase agreements, in the notes to the consolidated financial statements for further detail regarding this amount.
 Other Income, Net. For the twelve months ended December 31, 2024 other income, net primarily consisted of rental income and income recognized under our transition service agreements with Regeneron from the Regeneron Transaction. For the twelve months ended December 31, 2023, other income, net consisted of rental income and income recognized under our transition service agreements with bluebird bio.

 Liquidity and Capital Resources
 As of December 31, 2024, we had cash, cash equivalents and marketable securities of $183.6 million. Based on our current operating plans, including with respect to the ongoing commercialization of Abecma, we expect our cash, cash equivalents and marketable securities will be sufficient to fund current planned operations for at least the next twelve months from the date of filing this Annual Report. Our current operating plan is based on various assumptions. If we use our capital resources sooner than expected, we would evaluate further reductions in expense or obtaining additional financing. This may include pursuing a combination of public or private equity offerings, debt financings, collaborations, strategic alliances or licensing arrangements with third parties. This may also include the potential sale of shares of our common stock of up to $150.0 million in gross proceeds under the ATM facility established in November 2022 with Cowen and Company, LLC. No sales of common stock have occurred under this ATM as of the date of this Annual Report and we do not have any current plans to sell shares under the ATM. There can be no assurance that such financing will be available in sufficient amounts or on acceptable terms, if at all, and some could be dilutive to existing stockholders. If we are unable to obtain additional funding on a timely basis, we may be forced to significantly curtail, delay, or discontinue one or more of our planned research or development programs or be unable to expand our operations.
 We have incurred losses and have experienced negative operating cash flows for all periods presented. During the year ended December 31, 2024, we incurred a loss of $57.2 million and used $85.0 million of cash in operations. We expect to continue to generate operating losses and negative operating cash flows for the near future.

 Cash Flows
 The following table summarizes our cash flow activity:

 2024
 2023

 Net cash used in operating activities
 $
 (84,998)
 $
 (166,858)

 Net cash provided by investing activities

 80,763
 43,861

 Net cash provided by financing activities
 127,390

 Increase (decrease) in cash, cash equivalents and restricted cash and cash equivalents

 $
 (3,818)
 $
 4,393

 Cash Flows from Operating Activities
 Net cash used in operating activities was $85.0 million for the year ended December 31, 2024 and primarily consisted of a net loss of $57.2 million adjusted for non-cash items, including:
 • gain on sale to Novo of $48.0 million and loss on assets held for sale to Regeneron of $5.0 million;
 • stock-based compensation of $12.2 million;
 • depreciation and amortization of $7.1 million;
 • change in fair value of contingent consideration of $2.4 million; and
 • other non-cash items of $4.6, as well as the change in our net working capital.
 Net cash used in operating activities was $166.9 million for the year ended December 31, 2023 and primarily consisted of a net loss of $217.6 million adjusted for non-cash items, including stock-based compensation of $32.2 million, goodwill impairment charges of $12.1 million, depreciation and amortization of $10.3 million, and the change in fair value of contingent consideration of $0.2 million, as well as the change in our net working capital.
 Pursuant to the BMS Merger Agreement, we have agreed to various covenants and obligations, including, among others, to conduct our business in the ordinary course between the execution of the BMS Merger Agreement and the closing of the transactions described therein. Outside of certain limited exceptions, we may not take certain actions without BMS' consent, including (i) acquiring businesses and disposing of significant assets, (ii) incurring expenditures above specified thresholds; (iii) incurring or assuming any indebtedness, and (iv) issuing additional securities. We do not believe these restrictions will prevent us from meeting our ongoing costs of operations, working capital needs or capital expenditure requirements.
 Cash Flows from Investing Activities
 Net cash provided by investing activities for the year ended December 31, 2024 was $80.8 million and was due to:
 •$166.5 million of proceeds from maturities of marketable securities;
 •$25.1 million of proceeds from maturities of restricted investments; and
 • proceeds from the Novo Transaction of $38.0 million and proceeds from the Regeneron Transaction of $5.0 million.
 These cash inflows were partially offset by the purchase of marketable securities of $127.5 million, the purchase of restricted investments of $25.8 million, and the purchase of property, plant and equipment of $0.7 million.

 Net cash provided by investing activities for the year ended December 31, 2023 was $43.9 million and was driven by $304.9 million of proceeds from maturities of marketable securities and $18.0 million of proceeds from maturities of restricted investments, which was offset by $246.7 million related to purchases of marketable securities, purchases of property, plant and equipment of $13.9 million, and the purchase of restricted investments of $18.4 million.
 Cash Flows from Financing Activities
 Net cash provided by financing activities for the year ended December 31, 2024 was $0.4 million and was primarily due to net proceeds relating to the exercise of stock options and ESPP contributions.
 Net cash provided by financing activities for the year ended December 31, 2023 was $127.4 million and was primarily due to net proceeds received of $117.0 million from the issuance of common stock in a public offering in March 2023 along with net proceeds of $9.9 million from the issuance of common stock to Regeneron from the January 2023 Share Purchase Agreement.

 Funding Requirements
 We intend to incur costs in support of the ongoing commercialization of Abecma pursuant to our cost sharing arrangements with BMS, other capital expenditures, working capital requirements, and other general corporate activities.
 Based on our current operating plans, including with respect to the ongoing commercialization of Abecma, we expect that our cash, cash equivalents and marketable securities will be sufficient to fund current planned operations for at least the next twelve months from the date of filing these financial statements. We have based this estimate on assumptions that may prove to be wrong, and we could exhaust our available capital resources sooner than we expect.
 Because of the numerous risks and uncertainties associated with the development and commercialization of Abecma, we are unable to estimate the exact amount of our working capital requirements. The scope of our future funding requirements will depend on, and could increase significantly as a result of, many factors, including:
 the costs of activities, including clinical trials, sales, marketing, medical affairs, manufacturing and distribution, for Abecma;
 the cost and timing of hiring new employees or contractors to support our activities;
 the costs of preparing, filing and prosecuting patent applications, maintaining and enforcing our intellectual property rights and defending intellectual property-related claims; and
 the timing, receipt and amount of sales of, or milestone payments related to or royalties on Abecma, if any.
 A change in the outcome of any of these or other variables could significantly change the costs and timing associated with the development and commercialization of Abecma. Further, our operating plans may change in the future, and we may need additional funds to meet operational needs and capital requirements associated with such operating plans.
 Until such time, if ever, as we can generate positive operating cash flows, we may need to finance our operations through a combination of public or private equity offerings, debt financings, collaborations, strategic alliances or licensing arrangements with third parties. To the extent that we raise additional capital through the sale of equity or convertible debt securities, this could result in dilution and could adversely affect the rights of common stockholders. Debt financing and preferred equity financing, if available, may involve agreements that include restrictive covenants that limit our ability to take specified actions, such as incurring additional debt, making capital expenditures or declaring dividends. In addition, debt financing would result in increased fixed payment obligations.

 If we raise funds through collaborations, strategic alliances or licensing arrangements with third parties, we may have to relinquish valuable rights to our technologies, future revenue streams, research programs or any future product candidates or grant licenses on terms that may not be favorable to us.
 If we are unable to raise additional funds when needed, we may be required to delay, reduce or eliminate our product development for additional indications of Abecma or future commercialization efforts.

 Contractual Obligations and Commitments
 As of December 31, 2024 we had contractual obligations and commitments relating to our lease obligations, milestone and royalty payments, business combinations, and certain purchase commitments.
 Leases
 We lease certain office and laboratory space, primarily located in Cambridge, Massachusetts and Seattle, Washington, which was assigned to us in connection with its separation from bluebird bio. The lease at 60 Binney Street, Cambridge, Massachusetts for 253,108 square feet (the "Prime Lease") was previously entered into by bluebird bio with ARE-MA Region No. 40, LLC on September 21, 2015. The lease at 188 East Blaine Street in Seattle, Washington for 36,126 square feet was previously entered into by bluebird bio on July 18, 2018.
 In connection with the Regeneron Transaction, Regeneron agreed to sublease our facilities in Seattle, Washington and a portion of our facilities in Cambridge, Massachusetts. The expected sublease income will cover a majority of the future minimum commitments through 2027. Please refer to Note 8, Leases, in the notes to the consolidated financial statements included elsewhere in the Form 10-K for further information regarding our future minimum commitments under ASC 842 under our operating leases and Note 3, Asset Purchase Agreements, for further information on the closing on the transaction with Regeneron. Additionally, we were party to various contracts with contract research organizations and contract manufacturers that generally provide for termination on notice, with the exact amounts in the event of termination to be based on the timing of the termination and the terms of the agreement. The majority of these contracts were assumed by Regeneron upon or after closing of the Regeneron Transaction.
 Contingent Milestone and Royalty Payments
 Based on our development plans as of December 31, 2024, we may be obligated to make future development, regulatory and commercial milestone payments and royalty payments on future sales of specified products associated with our collaboration and license agreements. Payments under these agreements generally become due and payable upon achievement of such milestones or sales. Because the achievement of these milestones or sales had not occurred as of December 31, 2024, such contingencies have not been recorded in our financial statements. Amounts related to contingent milestone payments and sales-based royalties are not yet considered contractual obligations as they are contingent upon success.
 • Under a license agreement with Biogen Inc., which was attributed to us in the separation, pursuant to which we license certain patents and patent applications related to ide-cel, we are required to make payments related to certain development milestone obligations and must report on our progress in achieving these milestones on a periodic basis. We may be obligated to pay up to $23.0 million in the aggregate for each licensed product upon the achievement of remaining milestones. Upon commercialization of Abecma, which is covered by the in-licensed intellectual property, we are obligated to pay a percentage of net sales as a royalty in the low single digits.
 • Under a license agreement with the NIH, which was attributed to us in the separation, pursuant to which we license certain patent applications related to ide-cel, we have agreed to certain development and regulatory milestone obligations and must report on our progress in achieving these milestones on a periodic basis. We may be obligated to pay up to $9.7 million in the aggregate for a licensed product upon the achievement of these milestones. Upon commercialization of Abecma, which is covered by the in-licensed intellectual property, we are obligated to pay NIH a percentage of annual net sales as a royalty in the low single digits.

 The royalties payable under this license agreement are subject to reduction for any third-party payments required to be made, with a minimum floor in the low single digits.
 • Under a 2011 license agreement, Institut Pasteur granted a license to bluebird bio for the Licensed Pasteur IP. In February 2023, we entered into a partial assumption and assignment agreement with bluebird bio and Institut Pasteur, by which bluebird bio assigned us its rights, obligations and interests under the 2011 license agreement, to any and all uses of the Licensed Pasteur IP in connection with the prevention, diagnosis or treatment of oncological diseases or disorders and hemophilia. Prior to entering into the partial assignment and assumption agreement, the Licensed Pasteur IP was sublicensed by bluebird bio to us under the Intellectual Property License Agreement, dated as of November 3, 2021, entered into in connection with the Separation. After the expiration of the last valid patent covered by Licensed Pasteur IP, we terminated the agreement with Institut Pasteur, effective as of December 31, 2023.
 • In connection with the separation, bluebird bio granted us a perpetual, worldwide, non-exclusive, royalty-free, fully paid-up license (or, as the case may be, including with respect to patents licensed to bluebird bio by Research Development Foundation, or RDF sublicense) to certain intellectual property to allow us to use such intellectual property in connection with our ongoing and future research and development activities and product candidates. We terminated the RDF sublicense, effective as of November 11, 2023.
 • Concurrent with the sale of the manufacturing facility in Durham, North Carolina, bluebird bio entered into certain ancillary agreements, including two manufacturing agreements and a license agreement, or the "Resilience License Agreement", among others, which are collectively referred to as the "Ancillary Agreements". One of the manufacturing agreements, or the Development Manufacturing Supply Agreement, supports ongoing manufacturing for lentiviral vector for development candidates. The other manufacturing agreement for the future manufacturing of lentiviral vector for the commercial product marketed in collaboration with BMS, Abecma, or the Commercial Supply Agreement, was assigned by us to BMS on June 23, 2023. Certain rights and obligations under the Ancillary Agreements were assigned by bluebird bio to us on November 4, 2021 upon our separation of 2seventy bio from bluebird bio. The assignments under the Ancillary Agreements commit us to reimburse Resilience for an amount equal to 50% of the net operating losses of and relating to the manufacturing facility incurred during the twelve-month period ending on the first anniversary of the closing of the transaction, as calculated in accordance with the asset purchase agreement, subject to a cap of $15.0 million. During the second quarter of 2023, we paid a total of $14.2 million to Resilience for its share of net operating losses. The disposition of the net assets of the manufacturing facility previously assigned to us was reflected as a transfer to bluebird bio via a net parent investment as a result of bluebird bio's sale of such facility in our 2021 Annual Report on Form 10-K for the year ended December 31, 2021. As a result of the separation, our net parent investment balance was reclassified to additional paid-in capital. We are not a party to the sale of the manufacturing facility and, therefore, did not recognize any gain or loss arising from the transaction.
 Contingent Consideration Related to Business Combinations
 In connection with the Pregenen acquisition, bluebird bio agreed to make contingent cash payments to the former equity holders of Pregenen. All assets and liabilities related to the Pregenen acquisition, including the resulting goodwill and contingent consideration, was attributed to us in connection with the separation. In accordance with accounting guidance for business combinations, these contingent cash payments are recorded as a component of other non-current liabilities on our consolidated balance sheets at fair value. During the second quarter of 2017, a $5.0 million preclinical milestone was achieved, which resulted in a $5.0 million payment to the former equity holders of Pregenen during the third quarter of 2017. As of December 31, 2024 and 2023, the aggregate remaining undiscounted amount of contingent consideration potentially payable is $99.9 million. During 2024, we determined the probability of milestone achievement to be zero. As of December 31, 2024 and 2023, the fair value is zero and $2.4 million, respectively, reflected as a non-current liability in the consolidated balance sheets.

 Other purchase commitments
 Additionally, we are party to various contracts with contract research organizations and contract manufacturers that generally provide for termination on notice, with the exact amounts in the event of termination to be based on the timing of the termination and the terms of the agreement. As of December 31, 2024 there are no remaining purchase commitments to contract research organizations and contract manufacturers.

 Emerging Growth Company Status
 The Jumpstart Our Business Startups Act of 2012 permits an "emerging growth company" such as us to take advantage of an extended transition period to comply with new or revised accounting standards applicable to public companies until those standards would otherwise apply to private companies. We have elected not to "opt out" of such extended transition period, which means that when a standard is issued or revised and it has different application dates for public or private companies, we will adopt the new or revised standard at the time private companies adopt the new or revised standard and will do so until such time that we either (i) irrevocably elect to "opt out" of such extended transition period or (ii) no longer qualify as an emerging growth company. We may choose to early adopt any new or revised accounting standards whenever such early adoption is permitted for private companies.

 Item 7A. Quantitative and Qualitative Disclosures About Market Risk
 As a "smaller reporting company," as defined by Item 10 of Regulation S-K, we are not required to provide the information required by this item of Form 10-K.

 Item 8. Financial Statements and Supplementary Data.
 The financial statements and the report of our independent registered public accounting firm required to be filed pursuant to this Item 8 are appended to this Annual Report on Form 10-K. An index of those financial statements is found in Item 15 of this Annual Report on Form 10-K.

 Item 9. Changes in and Disagreements With Accountants on Accounting and Financial Disclosure
 None.

 Item 9A. Controls and Procedures
 Evaluation of Disclosure Controls and Procedures
 We maintain "disclosure controls and procedures," as defined in Rules 13a-15(e) and 15d-15(e) under the Securities Exchange Act of 1934, as amended, or the Exchange Act, that are designed to ensure that information required to be disclosed in the reports that we file or submit under the Exchange Act is (i) recorded, processed, summarized and reported within the time periods specified in the SEC's rules and forms and (ii) accumulated and communicated to our management, including our principal executive and principal financial officer, as appropriate to allow timely decisions regarding required disclosure. Our management recognizes that any controls and procedures, no matter how well designed and operated, can provide only reasonable assurance of achieving their objectives and our management necessarily applies its judgment in evaluating the cost-benefit relationship of possible controls and procedures. Our disclosure controls and procedures are designed to provide reasonable assurance of achieving their control objectives.
 Our management, with the participation of our principal executive officer and principal financial officer, has evaluated the effectiveness of our disclosure controls and procedures (as defined in Rules 13a-15(e) and 15d-15(e) under the Exchange Act) as of December 31, 2024, the end of the period covered by this Annual Report on Form 10-K. Based upon such evaluation, our principal executive officer and principal financial officer have concluded that our disclosure controls and procedures were effective at the reasonable assurance level as of such date.
 Management's Report on Internal Control Over Financial Reporting
 Our management is responsible for establishing and maintaining adequate internal control over financial reporting (as defined in Rules 13a-15(f) and 15d-15(f) under the Exchange Act) to provide reasonable assurance regarding the reliability of our financial reporting and the preparation of consolidated financial statements for external purposes in accordance with GAAP. Internal control over financial reporting is a process designed by, or under the supervision of, our principal executive officer and principal financial officer, and effected by our Board of Directors, management and other personnel, to provide reasonable assurance regarding the reliability of financial reporting and the preparation of financial statements for external purposes in accordance with generally accepted accounting principles and includes those policies and procedures that:
 • Pertain to the maintenance of records that accurately and fairly reflect in reasonable detail the transactions and dispositions of the assets of our company;
 • Provide reasonable assurance that transactions are recorded as necessary to permit preparation of financial statements in accordance with generally accepted accounting principles, and that our receipts and expenditures are being made only in accordance with authorizations of our management and directors; and
 • Provide reasonable assurances regarding prevention or timely detection of unauthorized acquisition, use or disposition of our assets that could have a material adverse effect on our financial statements.
 Management assessed our internal control over financial reporting as of December 31, 2024, the end of our fiscal year. Management based its assessment on criteria established in Internal Control—Integrated Framework issued by the Committee of Sponsoring Organizations of the Treadway Commission (2013 framework). Management's assessment included evaluation of elements such as the design and operating effectiveness of key financial reporting controls, process documentation, accounting policies, and our overall control environment.
 Based on this assessment, management has concluded that our internal controls over financial reporting were effective as of December 31, 2024 and provide reasonable assurance regarding the reliability of financial reporting and the preparation of financial statements for external reporting purposes in accordance with GAAP. We reviewed the results of management's assessment with the Audit Committee of our Board of Directors.

 Attestation Report of the Registered Public Accounting Firm
 This Annual Report on Form 10-K does not include an attestation report of our independent registered public accounting firm due to an exemption established by the JOBS Act for "emerging growth companies."
 Changes in Internal Control over Financial Reporting
 There were no changes in our internal control over financial reporting (as defined in Rules 13a-15(f) and 15d-15(f) under the Exchange Act) that occurred during the fourth quarter of 2024 that have materially affected, or are reasonably likely to materially affect, our internal control over financial reporting.
 Inherent Limitations on Effectiveness of Internal Controls
 In designing and evaluating the disclosure controls and procedures, management does not expect that our internal control over financial reporting will prevent or detect all errors and all fraud. A control system, no matter how well conceived and operated, can provide only reasonable, not absolute, assurance that the objectives of the control systems are met. Further, the design of a control system must reflect the fact that there are resource constraints, and the benefits of controls must be considered relative to their costs. The design of any disclosure controls and procedures also is based in part upon certain assumptions about the likelihood of future events, and there can be no assurance that any design will succeed in achieving its stated goals under all potential future conditions. Our management, including our principal executive officer and principal financial officer, believes that our disclosure controls and procedures and internal control over financial reporting are designed to provide reasonable assurance of achieving their objectives and are effective at the reasonable assurance level. However, our management does not expect that our disclosure controls and procedures or our internal control over financial reporting will prevent all errors and all fraud.

 Item 9B. Other Information
 From time to time, our officers (as defined in Rule 16a-1(f)) and directors may enter into Rule 10b5-1 or non-Rule 10b5-1 trading arrangements (as each such term is defined in Item 408 of Regulation S-K). During the three months ended December 31, 2024, our officers and directors took the following actions with respect to 10b5-1 trading arrangements:
 On November 12, 2024, William Baird, our President and Chief Executive Officer, adopted a Rule 10b5-1 trading plan, which is intended to satisfy the affirmative defense conditions of Exchange Act Rule 10b5-1(c), with respect to the sale of up to an aggregate of 59,410 shares of common stock of the Company pursuant to the terms of such trading plan. His Rule 10b5-1 trading arrangement is active through December 31, 2025.
 On November 17, 2024, Marcela Maus, a director, adopted a Rule 10b5-1 trading plan, which is intended to satisfy the affirmative defense conditions of Exchange Act Rule 10b5-1(c), with respect to the sale of up to an aggregate to be determined of shares of common stock of the Company pursuant to the terms of such trading plan. Her Rule 10b5-1 trading arrangement is active through December 31, 2025.

 Item 9C. Disclosure Regarding Foreign Jurisdictions that Prevent Inspections
 Not applicable.

 Item 10. Directors, Executive Officers and Corporate Governance
 Except as set forth below, the information required by this Item 10 is incorporated by reference from our definitive proxy statement to be filed with the SEC with respect to our 2025 Annual Meeting of the Stockholders or will be set forth in an amendment to this Annual Report to be filed on Form 10-K/A within 120 days after the end of the fiscal year ended December 31, 2024.
 We have adopted a Code of Business Conduct and Ethics that applies to all of our directors, officers and employees, including our principal executive officer and principal financial officer. The Code of Business Conduct and Ethics is posted on our website at
 We intend to satisfy the disclosure requirement under Item 5.05 of Form 8-K regarding an amendment to, or waiver from, a provision of this Code of Business Conduct and Ethics by posting such information on our website, at the address and location specified above and, to the extent required by the listing standards of The Nasdaq Global Stock Market, by filing a Current Report on Form 8-K with the SEC, disclosing such information.

 Item 11. Executive Compensation.
 The information required by this Item 11 is incorporated by reference from our definitive proxy statement to be filed with the SEC with respect to our 2025 Annual Meeting of the Stockholders or will be set forth in an amendment to this Annual Report to be filed on Form 10-K/A within 120 days after the end of the fiscal year ended December 31, 2024.

 Item 12. Security Ownership of Certain Beneficial Owners and Management and Related Stockholder Matters
 The information required by this Item 12 is incorporated by reference from our definitive proxy statement to be filed with the SEC with respect to our 2025 Annual Meeting of the Stockholders or will be set forth in an amendment to this Annual Report to be filed on Form 10-K/A within 120 days after the end of the fiscal year ended December 31, 2024.

 Item 13. Certain Relationships and Related Transactions, and Director Independence.
 The information required by this Item 13 is incorporated by reference from our definitive proxy statement to be filed with the SEC with respect to our 2025 Annual Meeting of the Stockholders or will be set forth in an amendment to this Annual Report to be filed on Form 10-K/A within 120 days after the end of the fiscal year ended December 31, 2024.

 Item 14. Principal Accounting Fees and Services
 The information required by this Item 14 is incorporated by reference from our definitive proxy statement to be filed with the SEC with respect to our 2025 Annual Meeting of the Stockholders or will be set forth in an amendment to this Annual Report to be filed on Form 10-K/A within 120 days after the end of the fiscal year ended December 31, 2024.

 Item 15. Exhibits and Financial Statement Schedules
 (a)The following documents are included on pages F-1 through F-47 attached hereto and are filed as part of this Annual Report on Form 10-K:
 (1)The following Report and Consolidated Financial Statements of the Company are included in this Annual Report on Form 10-K:
 • Report of Independent Registered Public Accounting Firm
 • Consolidated Balance Sheets
 • Consolidated Statements of Operations and Comprehensive Loss
 • Consolidated Statements of Stockholders' Equity
 • Consolidated Statements of Cash Flows
 • Notes to Consolidated Financial Statements
 (2)Financial Statement Schedules. All financial statement schedules have been omitted because they are not applicable, not required or the information required is shown in the financial statements or the notes thereto.
 (3)Exhibits. The exhibits required by Item 601 of Regulation S-K and Item 15(b) of this Annual Report on Form 10-K are listed in the Exhibit Index immediately preceding the signature page of this Annual Report on Form 10-K. The exhibits listed in the Exhibit Index are incorporated by reference herein.
 _______________

 Item 16. Form 10–K Summary
 We have elected not to include summary information.

 INDEX TO CONSOLIDATED FINANCIAL STATEMENTS

 Audited Annual Consolidated Financial Statements

 Pages

 Report of Independent Registered Public Accounting Firm (PCAOB ID: 00 42)

 Consolidated Balance Sheets

 Consolidated Statements of Operations and Comprehensive Loss

 Consolidated Statements of Equity

 Consolidated Statements of Cash Flows

 Notes to Consolidated Financial Statements

 Report of Independent Registered Public Accounting Firm
 To the Stockholders and the Board of Directors of 2seventy bio, Inc.
 Opinion on the Financial Statements
 We have audited the accompanying consolidated balance sheets of 2seventy bio, Inc. (the Company) as of December 31, 2024 and 2023, the related consolidated statements of operations and comprehensive loss, stockholders' equity and cash flows for each of the two years in the period ended December 31, 2024, and the related notes (collectively referred to as the "consolidated financial statements"). In our opinion, the consolidated financial statements present fairly, in all material respects, the financial position of the Company at December 31, 2024 and 2023, and the results of its operations and its cash flows for each of the two years in the period ended December 31, 2024, in conformity with U.S. generally accepted accounting principles.

 Basis for Opinion
 These financial statements are the responsibility of the Company's management. Our responsibility is to express an opinion on the Company's financial statements based on our audits. We are a public accounting firm registered with the Public Company Accounting Oversight Board (United States) (PCAOB) and are required to be independent with respect to the Company in accordance with the U.S. federal securities laws and the applicable rules and regulations of the Securities and Exchange Commission and the PCAOB.
 We conducted our audits in accordance with the standards of the PCAOB. Those standards require that we plan and perform the audit to obtain reasonable assurance about whether the financial statements are free of material misstatement, whether due to error or fraud. The Company is not required to have, nor were we engaged to perform, an audit of its internal control over financial reporting. As part of our audits we are required to obtain an understanding of internal control over financial reporting but not for the purpose of expressing an opinion on the effectiveness of the Company's internal control over financial reporting. Accordingly, we express no such opinion.
 Our audits included performing procedures to assess the risks of material misstatement of the financial statements, whether due to error or fraud, and performing procedures that respond to those risks. Such procedures included examining, on a test basis, evidence regarding the amounts and disclosures in the financial statements. Our audits also included evaluating the accounting principles used and significant estimates made by management, as well as evaluating the overall presentation of the financial statements. We believe that our audits provide a reasonable basis for our opinion.

 /s/ Ernst & Young LLP

 We have served as the Company's auditor since 2021.

 Boston, Massachusetts

 March 25, 2025

 Consolidated Balance Sheets

 2024
 2023

 Assets

 Current assets:

 $
 71,244
 $
 74,958

 Marketable securities
 103,510
 142,031

 Prepaid expenses
 4,721
 7,365

 Receivables and other current assets
 7,781
 13,411

 Total current assets
 187,256
 237,765

 Property, plant and equipment, net
 33,759
 58,150

 Marketable securities
 8,867
 4,816

 Intangible assets, net
 5,885
 6,594

 Operating lease right-of-use assets
 204,391
 219,958

 Restricted investments and other non-current assets

 39,352
 38,143

 Total assets
 $
 479,510
 $
 565,426

 Liabilities and Stockholders' Equity

 Current liabilities:

 Accounts payable
 $
 1,055
 $
 6,028

 Accrued expenses and other current liabilities
 22,672
 25,688

 Operating lease liability, current portion
 16,365
 12,660

 Deferred revenue, current portion
 —
 15,403

 Total current liabilities
 40,092
 59,779

 Deferred revenue, net of current portion
 —
 3,918

 Operating lease liability, net of current portion
 227,352
 244,013

 Other non-current liabilities
 1,260
 2,416

 Total liabilities
 268,704
 310,126

 Commitments and contingencies (Note 9)

 Stockholders' equity:

 Preferred stock, $ 0.0001 par value; 10,000 shares authorized, 0 shares issued and outstanding at December 31, 2024 and December 31, 2023

 —
 —

 Common stock, $0.0001 par value; 200,000 shares authorized, 51,589 and 50,632 shares issued and outstanding at December 31, 2024 and December 31, 2023 respectively

 Additional paid-in capital
 779,176
 766,716

 Accumulated other comprehensive income (loss)

 ( 204)

 Accumulated deficit
 ( 568,464)
 ( 511,217)

 Total stockholders' equity
 210,806
 255,300

 Total liabilities and stockholders' equity
 $
 479,510
 $
 565,426

 See accompanying notes to consolidated financial statements.

 Consolidated Statements of Operations and Comprehensive Loss

 2024
 2023

 Revenue:

 Service revenue
 $
 18,118
 $
 24,144

 19,744
 71,601

 Royalty and other revenue
 —
 4,642

 Total revenues
 37,862
 100,387

 Operating expenses:

 Research and development
 76,917
 230,758

 Cost of manufacturing for commercial collaboration
 18,010
 14,819

 Selling, general and administrative
 43,924
 69,414

 Share of collaboration loss
 4,553
 —

 12,303
 8,614

 Cost of royalty and other revenue
 —
 2,099

 Change in fair value of contingent consideration
 ( 2,415)

 Goodwill impairment charge

 —
 12,056

 Total operating expenses
 153,292
 337,995

 Loss from operations
 ( 115,430)
 ( 237,608)

 Interest income, net
 10,875
 12,413

 Other income, net
 4,347
 7,625

 Gain on sale to Novo

 47,987
 —

 Loss on assets held for sale to Regeneron

 ( 5,026)
 —

 Loss before income taxes

 Income tax expense
 —
 —

 $
 $

 Net loss per share - basic and diluted
 $
 ( 1.10)
 $
 ( 4.42)

 Weighted-average number of common shares used in
 computing net loss per share - basic and diluted

 52,218
 49,276

 Other comprehensive income:

 Other comprehensive income, net of tax benefit (expense) of $ 0.0 million and $ 0.0 million for the years ended December 31, 2024 and 2023, respectively.

 $
 $
 2,673

 Total other comprehensive income

 $
 $
 2,673

 Comprehensive loss
 $
 ( 56,954)
 $
 ( 214,897)

 See accompanying notes to consolidated financial statements.

 Consolidated Statements of Stockholders' Equity

 Common stock
 Additional paid-in capital
 Accumulated other comprehensive income (loss)

 Accumulated deficit
 Total stockholders' equity

 Shares
 Amount

 Balances at December 31, 2022

 37,928
 $
 $
 606,986
 $
 ( 2,877)
 $
 ( 293,647)
 $
 310,466

 Vesting of restricted stock units
 —
 —
 —
 —
 —

 Exercise of stock options
 —
 —
 —

 Issuance of common stock in public offering, net of issuance costs
 10,870
 117,003
 —
 —
 117,004

 Issuance of common stock to Regeneron
 1,115
 —
 9,859
 —
 —
 9,859

 —
 —
 —
 —

 Purchase of common stock under ESPP
 —
 —
 —

 Other comprehensive income
 —
 —
 —
 2,673
 —
 2,673

 —
 —
 —
 —

 Balances at December 31, 2023
 50,632
 $
 $
 766,716
 $
 ( 204)
 $
 ( 511,217)
 $
 255,300

 Vesting of restricted stock units
 —
 —
 —
 —
 —

 Exercise of stock options
 —
 —
 —

 —
 —
 —
 —

 Purchases of shares under ESPP
 —
 —
 —

 Other comprehensive income
 —
 —
 —
 —

 —
 —
 —
 —

 Balances at December 31, 2024

 51,589
 $
 $
 779,176
 $
 $
 ( 568,464)
 $
 210,806

 See accompanying notes to consolidated financial statements.

 Consolidated Statements of Cash Flows

 2024
 2023

 Cash flows from operating activities:

 $
 $

 Adjustments to reconcile net loss to net cash used in operating activities:

 Change in fair value of contingent consideration

 ( 2,415)

 Depreciation and amortization

 7,096
 10,285

 Stock-based compensation expense

 Goodwill impairment charge
 —
 12,056

 Gain on asset Sale to Novo
 ( 47,987)
 —

 Loss on assets held for sale to Regeneron
 5,026
 —

 Other non-cash items

 ( 4,620)
 ( 6,627)

 Changes in operating assets and liabilities:

 Prepaid expenses and other assets

 7,918
 15,735

 Operating lease right-of-use assets

 15,567
 20,927

 Accounts payable

 ( 4,397)
 ( 423)

 Accrued expenses and other liabilities

 ( 2,598)
 ( 27,713)

 Operating lease liabilities

 ( 12,956)
 ( 13,499)

 Deferred revenue

 ( 535)
 11,321

 Collaboration research advancement

 —
 ( 3,744)

 Net cash used in operating activities

 ( 84,998)
 ( 166,858)

 Cash flows from investing activities:

 Purchases of property, plant and equipment

 ( 707)
 ( 13,865)

 Proceeds from Regeneron Transaction
 5,000
 —

 Proceeds from Novo Transaction
 38,000
 —

 Proceeds from sale of equipment
 —

 Purchases of marketable securities

 ( 127,466)
 ( 246,743)

 Proceeds from maturities of marketable securities
 166,505
 304,899

 Purchase of restricted investments
 ( 25,805)
 ( 18,430)

 Proceeds from maturities of restricted investments
 25,060
 18,000

 Net cash provided by investing activities

 80,763
 43,861

 Cash flows from financing activities:

 Proceeds from issuance of common stock in public offering, net of issuance costs
 —
 117,004

 Proceeds from issuance of common stock to Regeneron, net of issuance costs
 —
 9,859

 Proceeds from exercise of stock options and ESPP contributions

 Net cash provided by financing activities

 127,390

 Increase (decrease) in cash, cash equivalents and restricted cash and cash equivalents
 ( 3,818)
 4,393

 Cash, cash equivalents and restricted cash and cash equivalents at beginning of year
 76,683
 72,290

 Cash, cash equivalents and restricted cash and cash equivalents at end of year
 $
 72,865
 $
 76,683

 Reconciliation of cash, cash equivalents and restricted cash and cash equivalents:

 $
 71,244
 $
 74,958

 Restricted cash and cash equivalents included in restricted investments and other non-current assets
 1,621
 1,725

 Total cash, cash equivalents and restricted cash and cash equivalents
 $
 72,865
 $
 76,683

 Supplemental cash flow disclosures:

 Purchases of property, plant and equipment included in accounts payable and accrued expenses

 $
 —
 $

 See accompanying notes to consolidated financial statements.

 Notes to Consolidated Financial Statements
 For the Years Ended December 31, 2024 and 2023

 1. Description of the business
 2seventy bio, Inc. (the "Company" or "2seventy bio") was incorporated in Delaware on April 26, 2021 and is a cell therapy company focused on the development and commercialization of transformative treatments for cancer. The Company, together with BMS, is delivering the first FDA approved CAR T therapy in multiple myeloma, Abecma, to patients in the United States. Please refer to Note 11, Collaborative arrangements and strategic partnerships, for further discussion of the collaboration with BMS.
 2seventy bio Securities Corporation is a wholly-owned subsidiary of the Company and was granted securities corporation status in Massachusetts for the 2021 tax year. 2seventy bio Securities Corporation has no employees.
 On January 29, 2024, the Company began undertaking a strategic realignment to focus on the development and commercialization of Abecma. In connection with the strategic realignment, the Company entered into an asset purchase agreement with Regeneron Pharmaceuticals, Inc. ("Regeneron") to sell to Regeneron substantially all of the assets related to its oncology and autoimmune cell therapy programs. The Regeneron Transaction closed on April 1, 2024 and Regeneron assumed all of the ongoing programs, infrastructure and personnel costs related to these programs. In June 2024, the Company announced the completion of an asset purchase agreement with Novo Nordisk A/S ("Novo") as part of its strategic realignment. Under the terms of the Novo Transaction, Novo acquired the Company's program for the research, development, manufacture, regulatory approval, and commercialization of gene therapy products exploiting the megaTAL Platform that is directed to the treatment, diagnosis and prevention of hemophilia.
 Going concern
 In accordance with Accounting Standards Codification 205-40, Going Concern, the Company evaluated whether there are conditions and events, considered in the aggregate, that raise substantial doubt about its ability to continue as a going concern within one year of the date that the consolidated financial statements are issued. The Company has incurred normal operating losses and has experienced negative operating cash flows for all historical periods presented. During the year ended December 31, 2024, the Company incurred a net loss of $ 57.2 million and used $ 85.0 million of cash in operations. The Company expects to continue to generate operating losses and negative operating cash flows for the near future.
 As of December 31, 2024, the Company had cash, cash equivalents and marketable securities of $ 183.6 million. Based on the Company's current operating plan, including with respect to the ongoing commercialization of Abecma, the Company expects that its cash, cash equivalents and marketable securities will be sufficient to fund current planned operations for at least the next twelve months from the date of filing this Annual Report on Form 10-K. The Company's current operating plan is based on various assumptions. If the Company uses its capital resources sooner than expected, it would evaluate further reductions in its expense or obtaining additional financing. This may include a combination of public or private equity offerings, debt financings, collaborations, strategic alliances or licensing arrangements with third parties. This may also include the potential sale of shares of the Company's common stock of up to $ 150.0 million in gross proceeds under the at-the-market ("ATM") facility established in November 2022 with Cowen and Company, LLC. No sales of common stock have occurred under this ATM as of the date of this Annual Report on Form 10-K and the Company does not currently have any plans to sell shares under the ATM.

 2. Summary of significant accounting policies and basis of presentation
 Basis of presentation
 The accompanying consolidated financial statements reflect the historical results of the operations, financial position and cash flows of the Company and have been prepared by the Company in accordance with accounting

 principles generally accepted in the United States ("GAAP"). Any reference in these notes to applicable guidance is meant to refer to the authoritative GAAP as included in the Accounting Standards Codification ("ASC") and Accounting Standards Updates of the Financial Accounting Standards Board.
 Amounts reported are computed based on thousands, except percentages or as otherwise noted. As a result, certain totals may not sum due to rounding.
 Principles of consolidation
 The accompanying consolidated financial statements include the accounts of the Company and its wholly owned subsidiaries. All intercompany transactions and accounts within the Company have been eliminated. Certain amounts presented in the prior period have been reclassified to conform to the current period presentation.
 The Company continually assesses whether it is the primary beneficiary of a variable interest entity as changes to existing relationships or future transactions may result in consolidation or deconsolidation of one or more collaborators or partners. In determining whether it is the primary beneficiary of an entity in which the Company has a variable interest, management applies a qualitative approach that determines whether the Company has both (1) the power to direct the economically significant activities of the entity and (2) the obligation to absorb losses of, or the right to receive benefits from, the entity that could potentially be significant to that entity.
 Use of estimates
 The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts in the financial statements and accompanying notes. Actual results could materially differ from those estimates. Management considers many factors in selecting appropriate financial accounting policies and controls, and in developing the estimates and assumptions that are used in the preparation of these financial statements. Management must apply significant judgment in this process. In addition, other factors may affect estimates, including: expected business and operational changes, sensitivity and volatility associated with the assumptions used in developing estimates, and whether historical trends are expected to be representative of future trends. The estimation process often may yield a range of potentially reasonable estimates of the ultimate future outcomes and management must select an amount that falls within that range of reasonable estimates. This process may result in actual results differing materially from those estimated amounts used in the preparation of the financial statements.
 Estimates and judgments are used in the following areas, among others: future undiscounted cash flows and subsequent fair value estimates used to assess potential and measure any impairment of long-lived assets, including intangible assets, the measurement of right-of-use assets and lease liabilities, sales forecasts and corresponding expiry dates utilized to determine our contingent liabilities for excess and obsolete inventory reserves as part of our collaboration with BMS, contingent consideration, stock-based compensation expense, accrued expenses, income taxes, and the assessment of the Company's ability to fund its operations for at least the next twelve months from the date of issuance of these financial statements. In addition, prior to the Regeneron Transaction, estimates and judgments were used in the Company's accounting for its revenue-generating arrangements, in particular as it relates to determining the stand-alone selling price of performance obligations, evaluating whether an option to acquire additional goods and services represents a material right, estimating the total transaction price, including estimating variable consideration and the probability of achieving future potential development and regulatory milestones, assessing the period of performance over which revenue may be recognized, and accounting for modifications to revenue-generating arrangements.
 Segment information
 In November 2023, the FASB issued Accounting Standards Update ("ASU") 2023-07, Segment Reporting: Improvements to Reportable Segment Disclosure ("Topic 280") to establish standards for reporting information about operating segments. Operating segments are defined as components of an enterprise engaging in business activities for which separate financial information is available and regularly reviewed by the chief operating decision maker ("CODM") in deciding how to allocate resources and in assessing performance. The Company operates in a single segment, focusing on researching, developing and commercializing potentially transformative treatments for

 cancer. Consistent with its operational structure, the Company's Chief Executive Officer ("CEO") is our CODM responsible for managing and allocating resources for the Company at a consolidated level. The CODM measures profitability on a reportable segment basis using net income (loss). Therefore, results of the Company's operations are reported on a consolidated basis for purposes of segment reporting. All material long-lived assets of the Company reside in the United States. Refer to Note 19, Segment information, for additional segment information.
 The Company considers all highly liquid investments purchased with original final maturities of 90 days or less from the date of purchase to be cash equivalents. Cash equivalents may consist of marketable securities with maturities of less than 90 days when purchased. Cash equivalents are reported at fair value.
 Restricted investments
 As of December 31, 2024 and 2023, restricted investments consists primarily of United States government agency securities and treasuries placed as collateral to letters of credit totaling $ 33.9 million and $ 32.8 million, respectively that are required to be maintained in connection with the Company's lease arrangements. The letters of credit are in the name of the Company's landlord and are required to fulfill lease requirements in the event the Company should default on its lease obligations. As of December 31, 2024 and 2023, the Company classified its restricted investments as non-current on the consolidated balance sheet based on the release dates of the restrictions. For further information on the Company's letters of credit, see Note 8, Leases.
 Marketable securities
 The Company's marketable securities are maintained by investment managers and consist of U.S. government agency securities and treasuries, corporate bonds and commercial paper. Debt securities are carried at fair value with the unrealized gains and losses included in other comprehensive income (loss) as a component of stockholders' equity until realized. Any premium arising at purchase is amortized to the earliest call date and any discount arising at purchase is accreted to maturity. Amortization and accretion of premiums and discounts are recorded in interest income, net. Realized gains and losses on debt securities are determined using the specific identification method and are included in other income, net.
 The Company classifies marketable securities with a remaining maturity when purchased of greater than three months as available-for-sale. Marketable securities with a remaining maturity date greater than one year are classified as non-current assets although these securities are available for use in the Company's current operations.
 The Company assesses its available-for-sale debt securities under the available-for-sale debt security impairment model in ASU 2016-13, Financial Instruments - Credit Losses (Topic 326): Measurement of Credit Losses on Financial Statements ("ASU 2016-13" or "ASC 326") as of each reporting date in order to determine if a portion of any decline in fair value below carrying value recognized on its available-for-sale debt securities is the result of a credit loss. The Company records credit losses in the consolidated statements of operations and comprehensive loss as credit loss expense within other income, net, which is limited to the difference between the fair value and the amortized cost of the security. To date, the Company has not recorded any credit losses on its available-for-sale debt securities.
 Accrued interest receivable related to the Company's available-for-sale debt securities is presented within receivables and other current assets on the Company's consolidated balance sheets. The Company has elected the practical expedient available to exclude accrued interest receivable from both the fair value and the amortized cost basis of available-for-sale debt securities for the purposes of identifying and measuring any impairment. The Company writes off accrued interest receivable once it has determined that the asset is not realizable. Any write offs of accrued interest receivable are recorded by reversing interest income, recognizing credit loss expense, or a combination of both. To date, the Company has not written off any accrued interest receivables associated with its marketable securities.
 Concentrations of credit risk and off-balance sheet risk

 Financial instruments that subject the Company to credit risk primarily consist of cash and cash equivalents, available-for-sale securities, and accounts receivable. Deposits are maintained with banks in the United States and such amounts may exceed the amount of insurance provided on such deposits. The Company has not experienced any losses on such accounts, and does not believe it is exposed to any unusual credit risk beyond the normal credit risk currently associated with commercial banking relationships. Cash deposits are insured by the Federal Deposit Insurance Corporations ("FDIC") up to $250,000. The Company has cash deposits in excess of the FDIC insured limit. The Company's marketable securities, which primarily consist of U.S. government agency securities and treasuries, corporate bonds and commercial paper, potentially subject the Company to concentrations of credit risk. The Company has adopted an investment policy that limits the amounts the Company may invest in any one type of investment and requires all investments held by the Company to be at least AA+/Aa1 rated, thereby reducing credit risk exposure. The Company's accounts receivable balance primarily consists of amounts owed from collaborative arrangement partners and royalties receivable under out-license agreements with various third parties. The Company monitors economic conditions to identify facts or circumstances that may indicate that any of its accounts receivable are at risk of collection.
 Fair value of financial instruments
 The Company has certain financial assets and liabilities recorded at fair value which have been classified as Level 1, 2 or 3 within the fair value hierarchy as described in the accounting standards for fair value measurements:
 Level 1—Fair values are determined utilizing quoted prices (unadjusted) in active markets for identical assets or liabilities that the Company has the ability to access at the measurement date.
 Level 2—Fair values are determined utilizing quoted prices for identical assets or liabilities in non-active markets, quoted prices for similar assets or liabilities in active markets, or other market observable inputs such as interest rates, yield curves and foreign currency spot rates.
 Level 3—Prices or valuations that require inputs that are both significant to the fair value measurement and unobservable.
 To the extent that valuation is based on models or inputs that are less observable or unobservable in the market, the determination of fair value requires more judgment. Accordingly, the degree of judgment exercised by the Company in determining fair value is greatest for instruments categorized in Level 3. A financial instrument's level within the fair value hierarchy is based on the lowest level of any input that is significant to the fair value measurement.
 Items measured at fair value on a recurring basis include marketable securities (see Note 4, Marketable securities, and Note 5, Fair value measurements) and restricted cash and cash equivalents, restricted investments, and contingent consideration (see Note 5, Fair value measurements). The carrying amounts of accounts receivable, accounts payable and accrued expenses approximate their fair values due to their short-term nature.
 Business combinations
 Business combinations are accounted for using the acquisition method of accounting. Using this method, the tangible and intangible assets acquired and the liabilities assumed are recorded as of the acquisition date at their respective fair values. The Company evaluates a business as an integrated set of activities and assets that is capable of being managed for the purpose of providing a return in the form of dividends, lower costs or other economic benefits and consists of inputs and processes that provide or have the ability to provide outputs. In an acquisition of a business, the excess of the fair value of the consideration transferred over the fair value of the net assets acquired is recorded as goodwill. In an acquisition of net assets that does not constitute a business, no goodwill is recognized.
 The consolidated financial statements include the results of operations of an acquired business after the completion of the acquisition.

 Intangible assets, net
 Intangible assets, net primarily consist of acquired core technology, net of accumulated amortization. The Company amortizes its intangible assets using the straight-line method over their estimated economic lives and periodically reviews for impairment.
 Contingent consideration receivable
 Under ASC 810, Consolidations, the Company has elected to use the loss recovery approach to account for contingent consideration receivable. Under this approach, if it is probable that contingent consideration will be received, an asset would be recognized and measured initially at the lesser of (i) the amount of probable future proceeds or (ii) the difference between the fair value of the consideration received, excluding the contingent consideration, and the carrying amount of the deconsolidated net assets.
 Contingent consideration payable
 Each reporting period, the Company remeasures the contingent consideration obligations associated with business combinations to their fair value and records within operating expenses increases or decreases in their fair value as change in fair value of contingent consideration within the consolidated and combined statements of operations and comprehensive loss. Changes in contingent consideration result from changes in the assumptions regarding probabilities of successful achievement of related milestones, the estimated timing in which the milestones may be achieved, and the discount rate used to estimate the fair value of the liability. Contingent consideration may change significantly as development of the Company's programs in certain indications progress and additional data is obtained, impacting the Company's assumptions. The assumptions used in estimating fair value require significant judgment. The use of different assumptions and judgments could result in a materially different estimate of fair value. See Note 5, Fair value measurements, for additional information.
 Property, plant and equipment
 Property, plant and equipment is stated at cost. Maintenance and repairs that do not improve or extend the lives of the respective assets are expensed to operations as incurred. Depreciation and amortization is calculated using the straight-line method over the estimated useful lives of the assets, which are as follows:

 Asset
 Estimated useful life

 Building
 40 years

 Computer equipment and software
 3 years

 Furniture and fixtures
 2 - 5 years

 Laboratory equipment
 5 - 10 years

 Leasehold improvements
 Shorter of the useful life or remaining lease term

 Impairment of long-lived assets
 The Company reviews long-lived assets when events or changes in circumstances indicate the carrying value of the assets may not be recoverable. Recoverability is measured by comparison of the book values of the assets to future net undiscounted cash flows that the assets are expected to generate. If such assets are considered to be impaired, the impairment to be recognized is measured by the amount by which the book value of the assets exceed their fair value, which is measured based on the projected discounted future net cash flows arising from the assets.
 Leases
 At the inception of an arrangement, the Company determines whether the arrangement is or contains a lease based on the relevant facts and circumstances present in the arrangement. Leases with a term greater than one year are recognized on the balance sheet as right-of-use assets and current and non-current lease liabilities, as applicable. The Company does not have material financing leases.

 Operating lease liabilities and their corresponding right-of-use assets are initially recorded based on the present value of lease payments over the expected remaining lease term. Certain adjustments to the right-of-use asset may be required for items such as incentives received. The interest rate implicit in lease contracts is typically not readily determinable. As a result, the Company utilizes its incremental borrowing rate to discount lease payments, which reflects the rate at which the Company could borrow on a collateralized basis the amount of the lease payments in the same currency, for a similar term, in a similar economic environment. To estimate its incremental borrowing rate, a credit rating applicable to the Company is estimated using a synthetic credit rating analysis since the Company does not currently have a rating agency-based credit rating.
 The Company has elected not to recognize leases with an original term of one year or less on the balance sheet. The Company typically only includes an initial lease term in its assessment of a lease arrangement. Options to renew a lease are not included in the Company's assessment unless it is reasonably certain that the Company will exercise its renewal option.
 Assumptions made by the Company at the commencement date are re-evaluated upon occurrence of certain events, including a lease modification. A lease modification results in a separate contract when the modification grants the lessee an additional right of use not included in the original lease and when lease payments increase commensurate with the stand-alone price for the additional right of use. When a lease modification results in a separate contract, it is accounted for in the same manner as a new lease.
 In accordance with ASC 842, components of a lease should be separated into lease components and non-lease components. The fixed and in-substance fixed contract consideration must be allocated based on the relative stand-alone prices to the lease components and non-lease components.
 Entities may elect not to separate lease and non-lease components. Rather, entities would account for each lease component and related non-lease component together as a single lease component. The Company has elected to account for lease and non-lease components together as a single lease component for all underlying assets and allocate all of the contract consideration to the lease component only.
 For purposes of distinguishing between operating and financing leases, ASC 842 allows for the use of judgment in determining whether the lease term is for a major part of the remaining economic life of the underlying asset and whether the present value of lease payments represents substantially all of the fair value of the underlying asset. The Company applies the bright line thresholds referenced in ASC 842-10-55-2 to assist in evaluating leases for appropriate classification. The aforementioned bright lines are applied consistently to the Company's entire portfolio of leases.
 Common stock warrants
 The Company's common stock warrants are evaluated pursuant to ASC 480, Distinguishing Liabilities from Equity ("ASC 480"), and ASC 815, Derivatives and Hedging ("ASC 815"). Management classifies its freestanding warrants as (i) liabilities, if the warrant terms allow settlement of the warrant exercise in cash, or (ii) equity, if the warrant terms only allow settlement in shares of common stock.
 Revenue recognition
 Under ASC Topic 606, Revenue from Contracts with Customers ("Topic 606"), an entity recognizes revenue when its customer obtains control of promised goods or services, in an amount that reflects the consideration that the entity expects to receive in exchange for those goods or services. To determine revenue recognition for arrangements that an entity determines are within the scope of Topic 606, the entity performs the following five steps: (i) identify the contract(s) with a customer; (ii) identify the performance obligations in the contract; (iii) determine the transaction price, including variable consideration, if any; (iv) allocate the transaction price to the performance obligations in the contract; and (v) recognize revenue when (or as) the entity satisfies a performance obligation. The Company only applies the five-step model to contracts when it is probable that the entity will collect the consideration to which it is entitled in exchange for the goods or services it transfers to the customer.

 Once a contract is determined to be within the scope of Topic 606, the Company assesses the goods or services promised within each contract and determines those that are performance obligations. Arrangements that include rights to additional goods or services that are exercisable at a customer's discretion are generally considered options. The Company assesses if these options provide a material right to the customer and if so, they are considered performance obligations. The identification of material rights requires judgments related to the determination of the value of the underlying good or service relative to the option exercise price. The exercise of a material right is accounted for as a contract modification for accounting purposes.
 The Company assesses whether each promised good or service is distinct for the purpose of identifying the performance obligations in the contract. This assessment involves subjective determinations and requires management to make judgments about the individual promised goods or services and whether such are separable from the other aspects of the contractual relationship. Promised goods and services are considered distinct provided that: (i) the customer can benefit from the good or service either on its own or together with other resources that are readily available to the customer (that is, the good or service is capable of being distinct) and (ii) the entity's promise to transfer the good or service to the customer is separately identifiable from other promises in the contract (that is, the promise to transfer the good or service is distinct within the context of the contract). In assessing whether a promised good or service is distinct, the Company considers factors such as the license terms, the research, manufacturing and commercialization capabilities of the collaboration partner and the availability of the associated expertise in the general marketplace. The Company also considers the intended benefit of the contract in assessing whether a promised good or service is separately identifiable from other promises in the contract. If a promised good or service is not distinct, an entity is required to combine that good or service with other promised goods or services until it identifies a bundle of goods or services that is distinct.
 The transaction price is determined and allocated to the identified performance obligations in proportion to their stand-alone selling prices ("SSP") on a relative SSP basis. SSP is determined at contract inception and is not updated to reflect changes between contract inception and when the performance obligations are satisfied. Determining the SSP for performance obligations requires significant judgment. In developing the SSP for a performance obligation, the Company considers applicable market conditions and relevant entity-specific factors, including factors that were contemplated in negotiating the agreement with the customer and estimated costs. The Company validates the SSP for performance obligations by evaluating whether changes in the key assumptions used to determine the SSP will have a significant effect on the allocation of arrangement consideration between multiple performance obligations.
 If the consideration promised in a contract includes a variable amount, the Company estimates the amount of consideration to which it will be entitled in exchange for transferring the promised goods or services to a customer. The Company determines the amount of variable consideration by using the expected value method or the most likely amount method. The amount of variable consideration included in the transaction price is constrained to the amount for which it is probable that a significant reversal of cumulative revenue recognized will not occur when the uncertainty related to the variable consideration is resolved. At the end of each subsequent reporting period, the Company re-evaluates the estimated variable consideration included in the transaction price and any related constraint, and if necessary, adjusts its estimate of the overall transaction price. Any such adjustments are recorded on a cumulative catch-up basis in the period of adjustment.
 If an arrangement includes development and regulatory milestone payments, the Company evaluates whether the milestones are considered probable of being reached and estimates the amount to be included in the transaction price using the most likely amount method. If it is probable that a significant revenue reversal would not occur, the associated milestone value is included in the transaction price. Milestone payments that are not within the Company's control or the licensee's control, such as regulatory approvals, are generally not considered probable of being achieved until those approvals are received.
 For arrangements with licenses of intellectual property that include sales-based royalties, including milestone payments based on the level of sales, and the license is deemed to be the predominant item to which the royalties relate, the Company recognizes royalty revenue and sales-based milestones at the later of (i) when the related sales occur, or (ii) when the performance obligation to which the royalty has been allocated has been satisfied.

 In determining the transaction price, the Company adjusts consideration for the effects of the time value of money if the timing of payments provides the Company with a significant benefit of financing. The Company does not assess whether a contract has a significant financing component if the expectation at contract inception is such that the period between payment by the licensees and the transfer of the promised goods or services to the licensees will be one year or less. The Company assessed each of its revenue generating arrangements in order to determine whether a significant financing component exists and concluded that a significant financing component does not exist in any of its arrangements.
 The Company recognizes as revenue the amount of the transaction price that is allocated to the respective performance obligation when (or as) each performance obligation is satisfied, either at a point in time or over time, and if over time recognition is based on the use of an output or input method.
 The Company recognizes revenue within the following financial statement captions:
 Service revenue
 To date, the Company's service revenue has primarily been generated from the elements of its collaboration arrangements with BMS and Novo that are accounted for pursuant to Topic 606, using the five-step model described above. As discussed further below, the Company analyzes its collaboration arrangements to assess whether they are within the scope of ASC 808, Collaborative Arrangements ("ASC 808") or Topic 606. For the elements of a collaboration arrangement that are more reflective of a vendor-customer relationship and therefore within the scope of Topic 606, the Company records the related revenue as service revenue on the consolidated statement of operations and comprehensive loss. Refer below for additional discussion around the Company's policy for recognizing collaborative arrangement revenue and the determination of whether elements of a collaboration arrangement are within the scope of ASC 808 or Topic 606. For the years ending 2024 and 2023, service revenue consisted of the following:

 Year Ended December 31,

 2024

 2023

 ide-cel ex-U.S. service revenue from BMS

 $
 10,611
 $
 14,751

 Service revenue from December 2021 agreement with Novo

 3,507
 5,765

 Other
 4,000
 3,628

 Total service revenue
 $
 18,118
 $
 24,144

 To date, the Company's collaborative arrangement revenue has been generated from its collaboration arrangements with BMS and Regeneron, as further described in Note 11, Collaborative arrangements and strategic partnerships. For the years ending 2024 and 2023, collaborative arrangement revenue consisted of the following:
 Year Ended December 31,

 2024

 2023

 U.S. Abecma collaboration with BMS

 $
 $

 Collaboration with Regeneron
 4,696
 21,591

 Total collaborative arrangement revenue
 $
 19,744
 $
 71,601

 The Company analyzes its collaboration arrangements to assess whether they are within the scope of ASC 808, which includes determining whether such arrangements involve joint operating activities performed by parties that are both active participants in the activities and exposed to significant risks and rewards dependent on the commercial success of such activities. This assessment is performed throughout the life of the arrangement based on changes in the responsibilities of all parties in the arrangement. For collaboration arrangements within the scope of ASC 808 that contain multiple elements, the Company first determines which elements of the collaboration are deemed to be within the scope of ASC 808 and those that are more reflective of a vendor-customer relationship and therefore within the scope of Topic 606 (refer above for further discussion of the Company's policy for recognizing

 service revenue pursuant to Topic 606). For elements of collaboration arrangements that are accounted for pursuant to ASC 808, an appropriate recognition method is determined and applied consistently, generally by analogy to Topic 606.
 In arrangements where the Company does not deem its collaborator to be its customer, payments to and from its collaborator are presented in the consolidated statements of operations and comprehensive loss based on the nature of the payments, as summarized in the table and further described below.

 Nature of Payment
 Statement of Operations Presentation

 The Company's share of net profits in connection with commercialization of products

 The Company's share of net losses in connection with commercialization of products
 Share of collaboration loss

 Net reimbursement to the Company for research and development expenses

 Net reimbursement to the collaborator for research and development expenses
 Research and development expense

 Where the collaborator is the principal in the product sales, the Company recognizes its share of any profits or losses, representing net product sales less cost of goods sold and shared commercial and other expenses, in the period in which such underlying sales occur and costs are incurred by the collaborator. The Company also recognizes its share of costs arising from research and development activities performed by collaborators in the period its collaborators incur such expenses.
 Royalty and other revenue
 The Company enters into out-licensing agreements that are within the scope of Topic 606. The Company does not have any material license arrangements that contain more than one performance obligation. The terms of such out-license agreements include the license of functional intellectual property, given the functionality of the intellectual property is not expected to change substantially as a result of the licensor's ongoing activities, and typically include payment of one or more of the following: non-refundable up-front license fees; development and regulatory milestone payments and milestone payments based on the level of sales; and royalties on net sales of licensed products. Nonrefundable up-front license fees are recognized as revenue at a point in time when the licensed intellectual property is made available for the customer's use and benefit, which is generally at the inception of the arrangement. Development and regulatory milestone fees, which are a type of variable consideration, are recognized as revenue to the extent that it is probable that a significant reversal will not occur. The Company recognizes royalty revenue and sales-based milestones at the later of (i) when the related sales occur, or (ii) when the performance obligation to which the royalty has been allocated has been satisfied.
 For a complete discussion of accounting for collaboration and other revenue-generating arrangements, see Note 11, Collaborative arrangements and strategic partnerships, and Note 12, Royalty and other revenue.
 Research and development expenses
 Research and development costs are charged to expense as costs are incurred in performing research and development activities, including salaries and benefits, facilities costs, overhead costs, clinical study and related clinical manufacturing costs, license and milestone fees, contract services, manufacturing costs for pre-launch inventory that did not qualify for capitalization, and other related costs. Up-front fees and milestones paid to third parties in connection with technologies that have not reached technological feasibility and do not have an alternative future use are expensed as research and development expense as incurred. In circumstances where amounts have been paid in excess of costs incurred, the Company records a prepaid expense. The Company accrues costs for clinical trial activities based upon estimates of the services received and related expenses incurred that have yet to be invoiced by the contract research organizations, clinical study sites, laboratories, consultants, or other clinical trial vendors that perform the activities. Where amounts owed to a collaboration partner exceed the Company's

 collaborative arrangement revenues in each quarterly period, such amounts are classified as research and development expense.
 Following the closing of the Novo Transaction and Regeneron Transaction, research and development expenses consist primarily of costs incurred for the development of Abecma in collaboration with BMS. Historical research and development expenses included costs for Abecma, as well as costs incurred for the development of product candidates that were sold to Regeneron and Novo in the second quarter of 2024.
 Cost of Manufacturing for Commercial Collaboration
 Cost of manufacturing for commercial collaboration consists of quality and other manufacturing costs incurred by the Company to support the manufacture of Abecma inventory sold by its collaborative partner, BMS, in both the U.S. and in ex-U.S. regions. These costs are subject to the cost sharing arrangement under the terms of the Company's collaboration agreement (the Amended Ide-cel CCPS) with BMS. For further information on the Amended Ide-cel CCPS, please refer to Note 11, Collaborative arrangements and strategic partnerships.
 The reimbursement from BMS for their share of the Company's U.S. quality and other manufacturing costs is recorded as collaborative arrangement revenue or share of collaboration loss in the consolidated statements of operations and comprehensive loss. The reimbursement from BMS for the Company's ex-U.S. quality and other manufacturing costs is recorded as service revenue in the consolidated statements of operations and comprehensive loss.
 The Company undertook a strategic realignment of resources and corporate restructuring in both 2023 and 2024, including an organizational workforce reduction and additional cost reduction measures. In accordance with ASC 420, Exit or Disposal Cost Obligations, the Company's restructuring and exit-related charges consisted of severance expenses and related benefit costs for employees affected by the workforce reduction and stock compensation associated with the modification of awards for certain affected employees. Refer to Note 15, Corporate restructuring, for additional details. Costs relating to both the 2023 and 2024 restructurings have been recorded as restructuring expenses in the consolidated statements of operations and comprehensive loss.
 Selling, General and Administrative Expenses
 Selling, general and administrative expenses consist primarily of salaries and related costs for personnel, including stock-based compensation and travel expenses for the Company's employees in executive, operational, finance, legal, business development, commercial, information technology, and human resource functions. Other selling, general and administrative expenses include facility-related costs, insurance, IT costs, professional fees for accounting, tax, legal and consulting services, directors' fees and expenses associated with obtaining and maintaining patents.
 Share of Collaboration Loss
 Share of collaboration loss represents the Company's share of net loss arising from product sales less cost of goods sold and shared commercial costs and other expenses related to the commercialization of a product where the collaborator is the principal in the product sales. For a complete discussion of accounting for share of collaboration loss, see Note 11, Collaborative arrangements and strategic partnerships.
 Cost of royalty and other revenue
 Cost of royalty and other revenue represents expense associated with amounts owed to third parties as a result of revenue recognized under the Company's out-license arrangements.

 The Company's share-based compensation programs grant awards that include stock options, restricted stock units, restricted stock awards, and shares issued under an employee stock purchase plan. Grants are awarded to employees and non-employees, including the Company's board of directors.
 The Company accounts for its stock-based compensation awards in accordance with FASB ASC Topic 718, Compensation—Stock Compensation ("ASC 718"). ASC 718 requires all stock-based payments, including grants of stock options and restricted stock units and modifications to existing stock options, to be recognized in the consolidated statements of operations and comprehensive loss based on their fair values.
 The Company's stock-based awards are subject to either service, performance-based, or market-based vesting conditions. Compensation expense related to awards with service-based vesting conditions is recognized on a straight-line basis based on the grant date fair value over the associated service period of the award, which is generally the vesting term. Compensation expense related to awards with performance-based vesting conditions is recognized based on the grant date fair value over the requisite service period using the accelerated attribution method to the extent achievement of the performance condition is probable.
 The Company estimates the fair value of its option awards using the Black-Scholes option pricing model, which requires the input of subjective assumptions, including (i) the expected stock price volatility, (ii) the calculation of expected term of the award, (iii) the risk-free interest rate, and (iv) expected dividends. Due to the lack of company specific historical and implied volatility data, the Company bases its estimate of expected volatility on the estimate and expected volatilities of a representative group of publicly traded companies. For these analyses, the Company selects companies with comparable characteristics including enterprise value, risk profiles, position within the industry, and with historical share price information sufficient to meet the expected life of the stock-based awards. It will continue to apply this process until sufficient historical information regarding the volatility of its own stock price becomes available. The Company has estimated the expected term of its employee stock options using the "simplified" method, whereby, the expected term equals the arithmetic average of the vesting term and the original contractual term of the option due to its lack of sufficient historical data. For stock options that were converted in accordance with the Employee Matters Agreement, as further described in Note 14, Stock-based compensation, the Company estimated the expected term to be the remaining contractual term of the awards as of the date of the separation. The risk-free interest rates for periods within the expected term of the option are based on the U.S. Treasury securities with a maturity date commensurate with the expected term of the associated award. The Company has never paid, and does not expect to pay, dividends in the foreseeable future.
 For performance-based restricted stock units that vest based on a total shareholder return metric, the vesting condition is considered a market condition as it vests based on the movement in share price of a company. The impact of the market condition is reflected in the award's fair value on the grant date, and the expense is recognized irrespective of whether the market condition is achieved as long as the required service is provided.
 The Company accounts for forfeitures as they occur. Stock-based compensation expense recognized in the financial statements is based on awards for which performance or service conditions are expected to be satisfied.
 Gain or Loss on Transaction
 The Company accounts for the disposition or sale of a business in accordance with Topic 810, Consolidations. This includes derecognition of assets related to the disposal group and then recognizing a gain or loss for the difference between the fair value of the consideration received and the book value of the disposal group under Topic 810.
 Other income, net
 Other income, net consists primarily of rental income from a third party, income recognized under the Company's transition service agreements with bluebird bio, and sublease income from bluebird bio, which terminated in 2023.
 Net loss per share

 Basic net loss per share is calculated by dividing net loss attributable to common stockholders by the weighted average number of common shares outstanding during the period, including the shares of common stock issuable upon the exercise of warrants that are exercisable for little or no consideration. Diluted net income per share is calculated by dividing the net income attributable to common stockholders by the weighted-average number of common equivalent shares outstanding for the period, including the shares of common stock issuable upon the exercise of warrants that are exercisable for little or no consideration as well as any dilutive effect from outstanding stock options, unvested restricted stock, restricted stock units, and employee stock purchase plan stock using the treasury stock method. Given that the Company recorded a net loss for each of the periods presented, there is no difference between basic and diluted net loss per share since the effect of common stock equivalents would be anti-dilutive and are, therefore, excluded from the diluted net loss per share calculation.
 The Company follows the two-class method when computing net loss per share in periods when issued shares that meet the definition of participating securities are outstanding. The two-class method determines net loss per share for each class of common and participating securities according to dividends declared or accumulated and participation rights in undistributed earnings. The two-class method requires income available to common stockholders for the period to be allocated between common and participating securities based upon their respective rights to received dividends as if all income for the period had been distributed. Accordingly, in periods in which the Company reports a net loss attributable to common stockholders when participating securities are outstanding, losses are not allocated to the participating securities.
 Income taxes
 The Company recognizes deferred tax assets and liabilities for the expected future tax consequences of events that have been included in the financial statements or tax returns. Deferred tax assets and liabilities are determined based on the difference between the financial statement and tax bases of assets and liabilities using enacted tax rates in effect for the year in which the differences are expected to reverse. Valuation allowances are provided, if based upon the weight of available evidence, it is more likely than not that some or all of the deferred tax assets will not be realized.
 The Company accounts for uncertain tax positions in accordance with the provisions of ASC 740. When uncertain tax positions exist, the Company recognizes the tax benefit of tax positions to the extent that the benefit will more likely than not be realized. The determination as to whether the tax benefit will more likely than not be realized is based upon the technical merits of the tax position as well as consideration of the available facts and circumstances. The Company accrues for potential interest and penalties related to unrecognized tax benefits in income tax expense.
 Comprehensive loss
 Comprehensive loss is composed of net loss and other comprehensive income (loss). Other comprehensive income (loss) consists of unrealized gains and losses on debt securities.
 New accounting pronouncements
 Recently adopted
 ASU No. 2023-07, Segment Reporting (Topic 280): Improvements to Reportable Segment Disclosure
 In November 2023, the FASB issued ASU 2023-07, Segment Reporting (Topic 280: Improvements to Reportable Segment Disclosures) ("ASU 2023-07"), which improves segment disclosure requirements, primarily through enhanced disclosure requirements for significant segment expenses. The improved disclosure requirements apply to all public entities that are required to report segment information, including those with only one reportable segment. The Company adopted this guidance effective for its fiscal year 2024 Annual Report and determined there

 was no impact on the Company's reportable segments identified and additional required disclosures have been included in Note 19, Segment Reporting.
 ASU No. 2023-09, Income Taxes (Topic 740): Improvements to Income Tax Disclosures
 In December 2023, the FASB issued ASU 2023-09, Income Taxes (Topic 740): Improvements to Income Tax Disclosures ("ASU 2023-09"), which is intended to enhance the transparency and decision usefulness of income tax disclosures. The improved disclosure requirements, primarily relating to the rate reconciliation and income taxes paid information, were adopted effective for the Company's fiscal year 2024 Annual Report. There was no material impact on the Company's financial position or results of operations upon adoption as included within Note 17, Income Taxes.
 To be adopted in future periods
 ASU 2024-03, Income Statement: Disaggregation of Income Statement Expenses
 In November 2024, the FASB issued ASU 2024-03, Income Statement: Disaggregation of Income Statement Expenses ("ASU 2024-03"), which requires disclosures about specific types of expenses included in the expense captions presented on the face of the income statement as well as disclosures about selling expenses. For public business entities, the guidance is effective for annual reporting periods beginning after December 15, 2026, with early adoption permitted. The Company is currently evaluating the impact of the guidance on its consolidated financial statements.

 3. Asset purchase agreements
 Regeneron Asset Purchase Agreement
 In January 2024, the Company and Regeneron entered into an asset purchase agreement (the Regeneron Transaction). The assets consisted of property, plant and equipment and prepaid expenses. As consideration, Regeneron agreed to pay the Company an upfront payment of $ 5.0 million and contingent consideration based on regulatory approval and sales-based royalties. Regeneron assumed certain programs, infrastructure and personnel costs related to the programs purchased. In accordance with Topic 360, Property, Plant, and Equipment, the Company determined that as of the signing of the asset purchase agreement in January 2024, the criterion to classify the assets to be sold to Regeneron as assets held for sale was met. The $ 17.7 million of property, plant and equipment and prepaid expenses to be sold to Regeneron were classified as assets held for sale on the Company's consolidated balance sheets as of March 31, 2024.
 As noted above, the Company received an upfront payment of $ 5.0 million upon closing of the Regeneron Transaction, which occurred on April 1, 2024. Moreover, the termination of the Regeneron Collaboration Agreement (as described in Note 11, Collaborative arrangements and strategic partnerships) was negotiated concurrently with the asset purchase agreement and as such, the Company derecognized $ 7.8 million of deferred revenue associated with the Regeneron Collaboration Agreement as part of the Regeneron Transaction. The cash received by the Company combined with the derecognition of the remaining deferred revenue totals $ 12.8 million and represents the approximate combined fair value of the assets sold to Regeneron under the asset purchase agreement. As such, in the first quarter of 2024, the Company recorded an impairment loss of $ 5.0 million, disclosed as the "loss on assets held for sale to Regeneron" on the consolidated statements of operations and comprehensive loss. This represents the excess of the carrying value of the assets to be transferred to Regeneron at the time the held for sale criteria was met. Upon the closing of the Regeneron Transaction on April 1, 2024 and the receipt of the $ 5.0 million upfront payment, the Company derecognized the assets held for sale and the deferred revenue discussed above from its consolidated balance sheets.
 In connection with the Regeneron Transaction, the Company entered into transition services agreements with Regeneron, under which the Company provides certain services to Regeneron to help facilitate an orderly transition of the business. In return for these services, Regeneron is required to pay certain agreed upon fees to reimburse the Company for costs incurred, without markup. As of December 31, 2024, $ 1.4 million of receivables associated with these transition services are included within receivables and other current assets on the Company's consolidated

 balance sheets. Income for services provided by the Company to Regeneron is included within other income, net within the consolidated statements of operations and comprehensive loss. Reimbursement for costs incurred, without markup, are netted against operating expenses on the consolidated statements of operations and comprehensive loss.
 Novo Asset Purchase Agreement
 In June 2024, the Company announced the completion of the Novo Transaction. As consideration, Novo paid the Company upfront consideration of $ 38.0 million, plus up to an additional $ 2.0 million that will be held back by Novo for 12 months and may be used to settle certain indemnification claims.
 No assets on the Company's consolidated balance sheet were transferred to Novo as part of the transaction. The termination of the Company's existing Collaboration and License Agreement with Novo (as described in Note 11, Collaborative arrangements and strategic partnerships) was negotiated concurrently with the asset purchase agreement and as such, the Company derecognized $ 11.0 million of deferred revenue associated with the Company's Novo Collaboration Agreement as part of the Novo Transaction.
 In connection with the Novo Transaction, the Company entered into a transition service agreement with Novo under which the Company provided certain services to Novo to help facilitate an orderly transition of the business following the sale. Consideration for these services was included in the initial purchase price and as such, $ 1.0 million, which represents the fair market value of the services to be performed, was deferred from the gain on the sale and was recognized over the six month term of the transition services agreement, which ended in December 2024.
 The $ 38.0 million cash consideration received by the Company (less the $ 1.0 million received for transition services to be provided by the Company) combined with the derecognition of the deferred revenue totals $ 48.0 million and represents the gain on the sale of asset to Novo. This is disclosed as the "gain on sale to Novo", on the consolidated statements of operations and comprehensive loss. As the Company has elected to use the loss recovery approach to account for contingent consideration receivable, the $ 2.0 million cash consideration held back by Novo will not be recognized until it is probable of being received.

 4. Marketable securities
 The following table summarizes the marketable securities held at December 31, 2024 and December 31, 2023 (in thousands):

 Amortized
cost/ cost
 Unrealized
 gains

 Unrealized
 losses

 Fair
 Value

 $
 67,690
 $
 $
 ( 9)
 $
 67,764

 Corporate bonds
 2,011
 —
 ( 1)
 2,010

 42,607
 ( 28)
 42,603

 Total
 $
 112,308
 $
 $
 ( 38)
 $
 112,377

 $
 101,566
 $
 $
 ( 85)
 $
 101,625

 45,188
 —
 45,222

 Total
 $
 146,754
 $
 $
 ( 85)
 $
 146,847

 No available-for-sale debt securities held as of December 31, 2024 or December 31, 2023 had remaining maturities greater than five years.

 The following table summarizes available-for-sale debt securities in a continuous unrealized loss position for less than and greater than twelve months, and for which an allowance for credit losses has not been recorded at December 31, 2024 and December 31, 2023 (in thousands):

 Less than 12 months
 12 months or greater
 Total

 Description

 $
 10,720
 $
 ( 9)
 $
 —
 $
 —
 $
 10,720
 $
 ( 9)

 Corporate bonds
 2,010
 ( 1)
 —
 —
 2,010
 ( 1)

 12,825
 ( 28)
 —
 —
 12,825
 ( 28)

 Total
 $
 25,555
 $
 ( 38)
 $
 —
 $
 —
 $
 25,555
 $
 ( 38)

 $
 45,850
 $
 ( 60)
 $
 1,475
 $
 ( 25)
 $
 47,325
 $
 ( 85)

 Total
 $
 45,850
 $
 ( 60)
 $
 1,475
 $
 ( 25)
 $
 47,325
 $
 ( 85)

 As discussed further in Note 8, Leases, the Company maintains letters of credit related to its leases in Cambridge and Seattle. A portion of this collateral is classified as restricted investments and included within restricted investments and other non-current assets on the consolidated balance sheets.
 The following table summarizes restricted investments held at December 31, 2024 and December 31, 2023 (in thousands):

 Amortized
cost/ cost
 Unrealized
 gains

 Unrealized
 losses

 Fair
 Value

 $
 33,845
 $
 $
 ( 25)
 $
 33,865

 Total
 $
 33,845
 $
 $
 ( 25)
 $
 33,865

 $
 33,072
 $
 $
 ( 365)
 $
 32,774

 Total
 $
 33,072
 $
 $
 ( 365)
 $
 32,774

 The following table summarizes restricted investments in a continuous unrealized loss position for less than and greater than twelve months, and for which an allowance for credit losses has not been recorded at December 31, 2024 and December 31, 2023 (in thousands):

 Less than 12 months
 12 months or greater
 Total

 Description

 $
 10,455
 $
 ( 23)
 $
 $
 ( 2)
 $
 11,451
 $
 ( 25)

 Total
 $
 10,455
 $
 ( 23)
 $
 $
 ( 2)
 $
 11,451
 $
 ( 25)

 $
 3,496
 $
 ( 4)
 $
 13,266
 $
 ( 361)
 $
 16,762
 $
 ( 365)

 Total
 $
 3,496
 $
 ( 4)
 $
 13,266
 $
 ( 361)
 $
 16,762
 $
 ( 365)

 Accrued interest receivable on the Company's available-for-sale debt securities and restricted investments, included within receivables and other current assets on the Company's consolidated balance sheets, totaled $ 0.9 million and $ 0.8 million as of December 31, 2024 and 2023, respectively. No accrued interest receivable was written off during the twelve months ended December 31, 2024 or 2023.
 The amortized cost of available-for-sale debt securities is adjusted for amortization of premiums and accretion of discounts to the earliest call date for premiums or to maturity for discounts. At December 31, 2024 and 2023, the balance in the Company's accumulated other comprehensive income (loss) was composed primarily of activity related to the Company's available-for-sale debt securities. There were no material realized gains or losses recognized on the sale or maturity of available-for-sale debt securities during the years ended December 31, 2024 or December 31, 2023.
 The Company determined that there was no material change in the credit risk of the above investments for the year ended December 31, 2024. As such, an allowance for credit losses was not recognized. As of December 31, 2024, the Company does not intend to sell such securities and it is not more likely than not that the Company will be required to sell the securities before recovery of their amortized cost bases.

 5. Fair value measurements
 The following table sets forth the Company's assets and liabilities that are measured at fair value on a recurring basis as of December 31, 2024 and 2023 (in thousands):

 Total
 Quoted prices in active markets
 (Level 1)

 Significant other observable inputs
 (Level 2)

 Significant unobservable inputs
 (Level 3)

 Assets:

 $
 71,244
 $
 71,244
 $
 —
 $
 —

 Marketable securities:

 U.S. government agency securities and treasuries
 67,764
 —
 67,764
 —

 Corporate bonds

 2,010
 —
 2,010
 —

 42,603
 —
 42,603
 —

 Restricted cash and cash equivalents
 1,621
 1,621
 —
 —

 Restricted investments
 33,864
 —
 33,864
 —

 Total assets
 $
 219,106
 $
 72,865
 $
 146,241
 $
 —

 Liabilities:

 Contingent consideration
 $
 —
 $
 —
 $
 —
 $
 —

 Total liabilities
 $
 —
 $
 —
 $
 —
 $
 —

 Assets:

 $
 74,958
 $
 74,958
 $
 —
 $
 —

 Marketable securities:

 U.S. government agency securities and treasuries
 101,625
 —
 101,625
 —

 45,222
 —
 45,222
 —

 Restricted cash and cash equivalents
 1,725
 1,725
 —

 Restricted investments
 32,774
 —
 32,774
 —

 Total assets
 $
 256,304
 $
 76,683
 $
 179,621
 $
 —

 Liabilities:

 Contingent consideration
 $
 2,415
 $
 —
 $
 —
 $
 2,415

 Total liabilities
 $
 2,415
 $
 —
 $
 —
 $
 2,415

 Marketable securities
 Marketable securities classified as Level 2 within the valuation hierarchy generally consist of U.S. government agency securities and treasuries, corporate bonds, and commercial paper. The Company estimates the fair values of these marketable securities by taking into consideration valuations obtained from third-party pricing sources. These pricing sources utilize industry standard valuation models, including both income and market-based approaches, for which all significant inputs are observable, either directly or indirectly, to estimate fair value. These inputs include market pricing based on real-time trade data for the same or similar securities, issuer credit spreads, benchmark yields, and other observable inputs. The Company validates the prices provided by its third-party pricing sources by understanding the models used, obtaining market values from other pricing sources and analyzing pricing data in certain instances.
 Contingent consideration payable

 In connection with bluebird bio's prior acquisition of Precision Genome Engineering, Inc. ("Pregenen"), the Company may be required to pay future consideration that is contingent upon the achievement of specified development, regulatory approvals or sales-based milestone events. Contingent consideration is measured at fair value and is based on significant unobservable inputs, which represents a Level 3 measurement within the fair value hierarchy. The valuation of contingent consideration uses assumptions the Company believes would be made by a market participant. The Company assesses these estimates on an on-going basis as additional data impacting the assumptions is obtained. Future changes in the fair value of contingent consideration related to updated assumptions and estimates are recognized within the consolidated statements of operations and comprehensive loss. In the absence of new information related to the probability of milestone achievement, changes in fair value will reflect changing discount rates and the passage of time. During the year-ended December 31, 2024, the Company determined the probability of milestone achievement to be zero and as a result reduced the fair value of contingent consideration included in other non-current liabilities on the consolidated balance sheets to zero.
 The table below provides a roll-forward of fair value of the Company's contingent consideration obligations that include Level 3 inputs (in thousands):

 2024

 2023

 Beginning balance
 $
 2,415
 $
 2,180

 Additions
 —
 —

 Changes in fair value
 ( 2,415)

 Payments
 —
 —

 Ending balance
 $
 —
 $
 2,415

 Please refer to Note 9, Commitments and contingencies, for further information.

 6. Property, plant and equipment, net
 Property, plant and equipment, net, consists of the following (in thousands):

 2024
 2023

 Computer equipment and software
 $
 4,965
 $
 6,156

 Office equipment
 6,330
 6,726

 Laboratory equipment
 4,162
 43,209

 Leasehold improvements
 48,340
 58,832

 Construction-in-progress
 —

 Total property, plant and equipment
 63,797
 115,061

 Less accumulated depreciation and amortization
 ( 30,038)
 ( 56,911)

 Property, plant and equipment, net
 $
 33,759
 $
 58,150

 Depreciation and amortization expense related to property, plant and equipment was $ 6.4 million and $ 9.6 million for the years ended December 31, 2024 and 2023, respectively.
 As part of the Regeneron Transaction, the Company transferred fixed assets with a net book value, prior to impairment, of $ 17.7 million to Regeneron. This consisted of laboratory equipment, leasehold improvements, and software and office equipment with net book values, prior to impairment, of $ 12.1 million, $ 5.5 million, and $ 0.1 million, respectively. For further detail regarding the Regeneron Transaction, please refer to Note 3, Asset Purchase Agreements.

 7. Accrued expenses and other current liabilities
 Accrued expenses and other current liabilities consist of the following (in thousands):

 2024
 2023

 Collaboration costs

 $
 9,378
 $
 5,681

 Royalties
 5,720
 9,702

 Employee compensation
 4,796
 4,639

 Clinical and contract research organization costs

 Manufacturing costs
 —
 1,764

 Property, plant, and equipment
 —

 Other
 2,320
 2,633

 Total accrued expenses and other current liabilities
 $
 22,672
 $
 25,688

 Accrued royalties decreased as of December 31, 2024 compared to December 31, 2023 due to decreased Abecma royalties owed to sublicensors as a result of lower Abecma net sales year over year. The increase in accrued collaboration research costs is attributable to an increase in the Company's accrual of amounts due to BMS under the collaboration agreement, which was primarily driven by an inventory reserve charge accrued for by 2seventy in the fourth quarter of 2024. The increase in accrued employee compensation was primarily driven by the timing of the 2023 annual bonus payout, which occurred in December 2023.

 8. Leases
 The Company leases certain office and laboratory space that was attributed to it in connection with the separation.
 60 Binney Street lease
 In September, 2015, bluebird bio entered into a lease agreement, which was attributed to the Company in connection with the separation. This is the Company's corporate headquarters and includes office and laboratory space located in a building (the "Building") at 60 Binney Street, Cambridge, Massachusetts (the "60 Binney Street Lease"). Under the terms of the 60 Binney Street Lease, starting on October 1, 2016, bluebird bio leased approximately 253,108 square feet of office and laboratory space at $ 72.50 per square foot per year, or $ 18.4 million per year in base rent, which is subject to scheduled annual rent increases of 1.75 % plus certain operating expenses and taxes. bluebird bio historically maintained a $ 13.8 million collateralized letter of credit which, subject to the terms of the lease and certain reduction requirements specified therein, including market capitalization requirements, may decrease to $ 9.2 million over time. Pursuant to a work letter entered into in connection with the 60 Binney Street Lease, the landlord contributed an aggregate of $ 42.4 million toward the cost of construction and tenant improvements for the Building. The lease would continue until March 31, 2027.
 In October 2021, bluebird bio entered into a consent to assignment and amendment to its lease agreement for its 60 Binney Street lease, pursuant to which bluebird bio's interest in the lease was assigned to the Company. In November 2021, the Company executed a $ 25.0 million letter of credit related to this lease. Under the assigned and amended lease agreement, the lease term was extended through March 31, 2034 with the 2022 base rent being $ 90.00 per square foot per year, or $ 22.8 million per year in base rent, subject to scheduled annual rent increases of 3.0 % plus certain operating expenses and taxes. Starting April 1, 2026, the base rent will reset to $ 118.41 per square foot per year, or $ 30.0 million per year in base rent, subject to scheduled annual rent increases of 3.0 % plus certain operating expenses and taxes. Pursuant to a work letter entered into in connection with the 60 Binney Street assignment and amended lease agreement, the landlord agreed to contribute up to an aggregate of $ 19.1 million toward the cost of tenant improvements for the leased space. As of December 31, 2024, the Company has spent $ 36.6 million related to the build-out of the drug product manufacturing facility within its Cambridge, Massachusetts headquarters and has received $ 18.9 million in reimbursements, net of administrative fees.

 The Company has classified this lease as an operating lease and recorded a right-of-use asset and lease liability. The Company is recognizing rent expense on a straight-line basis throughout the remaining term of the lease.
 In connection with the Regeneron Transaction, Regeneron agreed to sublease a portion of the Company's facilities in Cambridge, Massachusetts. As part of the sublease agreement with Regeneron (the "Subtenant"), the Company agreed to sublease approximately 159,106 square feet of space in Cambridge. The Company remains the primary obligor of the lease. The monthly base rent for the sublease is equal to the rate per square foot paid by the Company, which is subject to annual rent increases.
 In addition to base rent, the Subtenant is responsible for its allocated share of costs incurred and expenditures made by the Company in the operation and management of the subleased space. The Subtenant has agreed to pay its proportionate share ( 63 %) of all operating expenses, taxes, insurance, utilities storage, parking fees and all other additional rent payable by the Company under the Prime Lease.
 Sublease income from Regeneron will cover a majority of the Company's future minimum lease commitments under the 60 Binney Street Lease through 2027. Total sublease income for the twelve months ended December 31, 2024 related to the sublease of the Prime Lease was approximately $ 14.7 million. This income is netted against the Company's rent expense, which is included within operating expenses in the consolidated statements of operations and comprehensive loss.
 Seattle, Washington leases
 In July 2018, bluebird bio entered into a lease agreement for office and laboratory space located in a portion of a building in Seattle, Washington, which was amended in October 2018 to increase the total rentable space to approximately 36,126 square feet at $ 54.00 per square foot in base rent per year, subject to scheduled annual rent increases of 2.5 % plus certain operating expenses and taxes. The lease commenced on January 1, 2019 and the lease term will continue through January 31, 2027. The Company has classified this lease as an operating lease and recorded a right-of-use asset and lease liability at lease commencement.
 In September 2019, bluebird bio entered into a second amendment to the lease (the "Second Amendment"), which added approximately 22,188 square feet to the existing space and extended the lease term of the entire premises by 16 months, or until April 2028, with a five-year option to extend the term. Fixed monthly rent for the expanded space will be incurred at a rate of $ 62.80 per square foot per year beginning in January 2021, subject to annual increases of 2.5 %. The execution of the Second Amendment was deemed to be a lease modification representing two separate contracts under ASC 842. One contract is related to a new right-of-use for the expanded 22,188 square feet of space, for which an additional right-of-use asset and lease liability was recognized upon lease commencement, and the other is related to the modification of term for the original 36,126 square feet of space. The original Seattle lease and the related amendments were assigned to the Company in connection with the separation. In November 2021, the Company executed a $ 5.0 million letter of credit related to this lease.
 In September 2020, bluebird bio entered into a sublease agreement (the "2020 Seattle Sublease Agreement") for the 22,188 square feet added under the Second Amendment at a fixed monthly rent of $ 62.80 per square foot per year beginning in January 2021, subject to annual increases of 2.5 %. The sublease term will continue through April 2028. The sublease was assigned to the Company in connection with the separation.
 In connection with the Regeneron Transaction, Regeneron agreed to fully sublease the remainder of the Company's facilities in Seattle (the "Regeneron Seattle Sublease"), which is approximately 36,126 square feet of space. The Company remains the primary obligor of the lease and the monthly base rent for the sublease is equal to the rate per square foot paid by the Company, which is subject to annual rent increases.
 Sublease income from the 2020 Seattle Sublease and the Regeneron Seattle Sublease will cover all of the Company's future minimum lease commitments under the Seattle head lease. The Company is recognizing rent expense on a straight-line basis throughout the remaining term of the head lease. The head lease and the 2020 Seattle Sublease are accounted for as two separate contracts with the income from the sublease presented as other income, separately from the lease expense on the head lease. Income related to the Regeneron sublease is netted against the Company's rent expense, which is included within operating expenses in the consolidated statements of operations

 and comprehensive loss. Total sublease income for the twelve months ended December 31, 2024 related to the sublease of the Seattle lease was approximately $ 3.2 million.
 Summary of all lease costs recognized under ASC 842
 The following table contains a summary of the lease costs recognized under ASC 842 and other information pertaining to the Company's operating leases for the years ended December 31, 2024 and 2023 (in thousands):

 For the year ended December 31,

 2024
 2023

 Lease cost (1)(2)

 Operating lease cost
 $
 31,441
 $
 32,636

 Total lease cost
 $
 31,441
 $
 32,636

 Other information

 Operating cash flows used for operating leases(3)

 $
 28,750
 $
 27,927

 Weighted average remaining lease term
 8.9 years
 9.9 years

 Weighted average discount rate
 5.49
 %
 5.48
 %

 ________________
 (1)Short-term lease costs incurred by the Company for the twelve months ended December 31, 2024 and 2023 were immaterial.
 (2)Lease costs exclude total sublease income received from Regeneron of $ 16.5 million.
 (3)Operating cash flows used for operating leases excludes sublease payments received from Regeneron of $ 14.8 million.

 Rent expense is calculated on a straight-line basis over the term of the lease. Rent expense recognized under all leases, net of Regeneron sublease income discussed above and including additional variable costs for utilities, parking, maintenance, and real estate taxes that are not included within lease costs in the table above, was $ 18.2 million and $ 43.4 million for the years ended December 31, 2024 and 2023, respectively.
 As of December 31, 2024, future minimum commitments under ASC 842 under the Company's operating leases were as follows (in thousands):

 Maturity of lease liabilities
 As of December 31, 2024

 2025
 $
 29,498

 2026
 32,920

 2027
 35,086

 2028
 33,125

 2029 and thereafter
 182,171

 Total lease payments
 312,800

 Less: imputed interest
 ( 69,083)

 Total operating lease liabilities
 $
 243,717

 As discussed above, in connection with the Regeneron Transaction, Regeneron agreed to sublease the Company's facilities in Seattle, Washington for the remaining term of the lease and a portion of the Company's facilities in Cambridge, Massachusetts through at least March 2028. The expected sublease income will cover all future minimum commitments for the Company's facility in Seattle, Washington and a majority of the future minimum commitments through 2027 for the Company's facilities in Cambridge, Massachusetts.

 9. Commitments and contingencies
 Lease commitments

 The Company leases certain office and laboratory space in Cambridge, MA and Seattle, WA. Refer to Note 8, Leases, for further information on the terms of these lease agreements. In connection with the Regeneron Transaction, Regeneron agreed to sublease our facilities in Seattle, Washington and a portion of our facilities in Cambridge, Massachusetts.
 Contingent milestone and royalty payments
 Certain agreements that were assigned by bluebird bio to the Company in connection with the separation relate principally to licensed technology and may require future payments relating to milestones that may be met in subsequent periods or royalties on future sales of specified products. Additionally, to the extent an agreement relating to licensed technology was not attributed to the Company, bluebird bio entered into a sublicense with the Company, which may require future milestone and/or royalty payments. Please refer to Note 11, Collaborative arrangements and strategic partnerships, for further information on the BMS, Regeneron, and Novo and Note 12, Royalty and other revenue, for further information on license agreements.
 Based on the Company's development plans as of December 31, 2024, the Company may be obligated to make future development, regulatory and commercial milestone payments and royalty payments on future sales of specified products. Payments under these agreements generally become due and payable upon achievement of such milestones or sales. When the achievement of these milestones or sales has not occurred, such contingencies are not recorded in the Company's financial statements. As further discussed in Note 11, Collaborative arrangements and strategic partnerships, BMS assumed responsibility for amounts due to licensors as a result of any future ex-U.S. sales of Abecma.
 Contingent consideration related to business combinations
 On June 30, 2014, bluebird bio acquired Pregenen. All assets and liabilities related to the Pregenen acquisition, including the resulting goodwill and contingent consideration, were attributed to the Company in connection with the separation. The Company may be required to make up to an additional $ 99.9 million in remaining future contingent cash payments to the former equity holders of Pregenen upon the achievement of certain commercial milestones related to the Pregenen technology. In accordance with accounting guidance for business combinations, contingent consideration liabilities are required to be recognized on the consolidated balance sheets at fair value. Estimating the fair value of contingent consideration requires the use of significant assumptions primarily relating to probabilities of successful achievement of certain clinical and commercial milestones, the expected timing in which these milestones will be achieved and discount rates. The use of different assumptions could result in materially different estimates of fair value. As of December 31, 2024, the Company determined the probability of milestone achievement to be zero and as a result reduced the fair value of contingent consideration included in other non-current liabilities on the consolidated balance sheets to zero. Please refer to Note 5, Fair value measurements, for further information.
 Other purchase commitments
 Additionally, 2seventy bio was party to various contracts with contract research organizations and contract manufacturers that generally provide for termination on notice, with the exact amounts in the event of termination to be based on the timing of the termination and the terms of the agreement. The majority of these contracts were assumed by Regeneron upon or after closing of the Regeneron Transaction. As a result, no purchase commitments remain as of December 31, 2024.
 Contingent liabilities
 As of December 31, 2024, the Company has recorded a contingent liability under its collaboration with BMS related to a charge to write-down excess vector inventory used in the manufacture of Abecma. As of the date of this report, there is uncertainty around the final amount of the write-down charge the Company will owe to BMS as the parties are not aligned on the portion of the charge attributed to the U.S. under the collaboration arrangement. As such, the Company has determined there to be a range of possible unfavorable outcomes with a low end of $ 11.8 million and a high end of $ 26.3 million. In accordance with ASC 450, Contingencies, as no amount within the range of loss is a better estimate than any other amount, the Company has accrued for the minimum amount in the

 range, which is included within accrued expenses and other current liabilities on the consolidated balance sheets. As noted in Note 20, Subsequent events, on March 10, 2025, the Company and BMS entered into an agreement and plan of merger pursuant to which BMS will acquire all the issued and outstanding shares of common stock of the Company. This transaction is expected to close in the second quarter of 2025. Upon close, the contingent liability recorded above will no longer be relevant as the Company will become a wholly owned subsidiary of BMS.
 Litigation
 From time to time, the Company expects to be party to various claims and complaints arising in the ordinary course of business. However, the Company is not currently a party to any litigation or legal proceedings that, in the opinion of its management, are probable of having a material adverse effect on its business. The Company enters into standard indemnification agreements in the ordinary course of business. Pursuant to these agreements, the Company indemnifies, holds harmless, and agrees to reimburse the indemnified party for losses suffered or incurred by the indemnified party, generally the Company's business partners. In addition, pursuant to the separation agreement with bluebird bio, the Company indemnifies, holds harmless, and agrees to reimburse bluebird bio for its indemnification obligations with respect to the Company's business partners, relating to the Company's business or arising out of the Company's activities, in the past or to be conducted in the future. The term of these indemnification agreements is generally perpetual any time after execution of the agreement. The maximum potential amount of future payments the Company could be required to make under these indemnification agreements is unlimited. Management does not believe that any ultimate liability resulting from any of these claims will have a material adverse effect on its results of operations, financial position, or liquidity. However, management cannot give any assurance regarding the ultimate outcome of any claims, and their resolution could be material to operating results for any particular period.
 The Company indemnifies each of its directors and officers for certain events or occurrences, subject to certain limits, while the officer or director is or was serving at the Company's request in such capacity, as permitted under Delaware law and in accordance with its certificate of incorporation and by-laws and indemnification agreements entered into with each of its directors and officers. The term of the indemnification period will last as long as a director or officer may be subject to any proceeding arising out of acts or omissions of such director or officer in such capacity. The maximum amount of potential future indemnification is unlimited; however, the Company holds director and officer liability insurance.

 10. Stockholders' equity
 The Company is authorized to issue 200.0 million shares of common stock. Holders of common stock are entitled to one vote per share. Holders of common stock are entitled to receive dividends, if and when declared by the Company's board of directors, and to share ratably in the Company's assets legally available for distribution to the Company's shareholders in the event of liquidation. Holders of common stock have no preemptive, subscription, redemption or conversion rights. As of December 31, 2024, the Company had 51.6 million shares of common stock issued and outstanding. As of December 31, 2023, the Company had 50.6 million shares of common stock issued and outstanding.
 In January 2023, the Company entered into a Share Purchase Agreement with Regeneron, pursuant to which it sold 1,114,827 shares of its common stock to Regeneron, subject to certain restrictions, for an aggregate cash price of approximately $ 20.0 million. The purchase price represents $ 9.9 million worth of common stock plus a $ 10.1 million premium, which represents collaboration deferred revenue. Details regarding the recognition of this deferred revenue as revenue are included below in Note 11, Collaborative arrangements and strategic partnerships.
 In March 2023, the Company sold 10,869,566 shares of common stock through an underwritten public offering at a price per share of $ 11.50. This resulted in aggregate net proceeds to the Company of approximately $ 117.0 million, after deducting underwriting fees and offering expenses. The underwriters did not exercise their option to purchase up to 1,630,434 additional shares of common stock and therefore no additional proceeds were received.
 The Company is authorized to issue 10.0 million shares of preferred stock in one or more series and to fix the powers, designations, preferences and relative participating option or other rights thereof, including dividend rights,

 conversion rights, voting rights, redemption terms, liquidation preferences and the number of shares constituting any series, without any further vote or action by the Company's shareholders. As of December 31, 2024 and 2023, the Company had no shares of preferred stock issued or outstanding.
 Reserved for future issuance
 The Company has reserved for future issuance the following number of shares of common stock (in thousands):

 2024

 2023

 Options to purchase common stock (1)

 3,915
 3,678

 Restricted stock units

 3,519
 2,239

 2021 Stock Option and Incentive Plan
 1,016

 2021 Employee Stock Purchase Plan

 Pre-funded warrants to purchase common stock

 9,910
 8,098

 (1) Outstanding stock options include awards outstanding to employees of bluebird bio.

 11. Collaborative arrangements and strategic partnerships
 To date, the Company's service and collaborative arrangement revenue has been primarily generated from collaboration arrangements with BMS, Regeneron, and Novo, each as further described below. Concurrent with the closings of the Regeneron Transaction and the Novo Transaction, the Regeneron Collaboration Agreement and the Novo Collaboration Agreement were terminated (respectively) with certain provisions surviving, as further described below.
 Bristol Myers Squibb
 The Company and BMS are party to the BMS Collaboration Agreement, several amendments to the BMS Collaboration Agreement, license agreements, and the Ide-cel CCPS. Refer to the 2023 Annual Report on 10-K for historical information regarding these agreements, including prior accounting analyses and conclusions that are no longer relevant to the financial information presented in these consolidated financial statements.
 Abecma
 Under the Ide-cel CCPS, the Company shares equally in the profit and loss related to the development and commercialization of ide-cel in the United States (marketed as Abecma). The Company has no remaining financial rights with respect to the development or commercialization of ide-cel outside of the United States. The Company accounts for its collaborative arrangement efforts with BMS in the United States within the scope of ASC 808 given that both parties are active participants in the activities and both parties are exposed to significant risks and rewards dependent on the commercial success of the activities. The calculation of collaborative activity to be recognized for joint Abecma efforts in the United States is performed on a quarterly basis and is independent of previous quarterly activity. This may result in fluctuations between revenue and expense recognition period over period, depending on the varying extent of effort performed by each party during the period. The Company recognizes revenue related to the combined unit of accounting for the ex-U.S. license and lentiviral vector manufacturing services under Topic 606.
 Ide-cel U.S. Share of Collaboration Profit or Loss
 The U.S. commercial and development activities under the Amended Ide-Cel CCPS are within the scope of ASC 808. On a quarterly basis, the Company determines its share of collaboration profit or loss for commercial activities (i.e., commercial sales of Abecma by BMS). The Company's share of any collaboration profit for commercial activities is recognized as collaborative arrangement revenue and its share of any collaboration loss for commercial activity is recognized as an operating expense and classified as share of collaboration loss on the Company's consolidated statements of operations and comprehensive loss.

 The Company is also responsible for equally sharing in the ongoing ide-cel research and development activities being conducted by BMS in the United States as BMS continues conducting ongoing clinical studies to support the use of Abecma in earlier lines of therapy. The net amount owed to BMS for research and development activities determined on a quarterly basis is classified as research and development expense on the statements of operations and comprehensive loss. If BMS is obligated to reimburse the Company because the Company's research and development costs exceeds BMS' research and development costs in a particular quarterly period, the net amount is recorded as collaborative arrangement revenue.
 The following tables summarize the components utilized in the Company's quarterly calculation of collaborative arrangement revenue or share of collaboration loss under the BMS collaboration arrangement for the years ended December 31, 2024 and 2023 (in thousands). The amounts reported for these periods represent the Company's share of BMS' Abecma product revenue, cost of goods sold, and selling costs, along with reimbursement by BMS of commercial costs incurred by the Company, and exclude expenses related to ongoing development, which are separately reflected in the consolidated statements of operations and comprehensive loss as described below.

 Abecma U.S. Collaboration Profit/Loss Share

 March 31, 2024

 June 30, 2024

 September 30, 2024

 2seventy's share of profits (losses), net of 2seventy's share of BMS costs for commercial activities
 $
 ( 1,975)
 $
 3,549
 $
 9,617
 $
 ( 4,494)
 $
 6,697

 Reimbursement from BMS for 2seventy costs of commercial manufacturing and commercial activities
 1,067
 1,171
 3,798

 Collaborative arrangement revenue (1)

 $
 —
 $
 4,364
 $
 10,684
 $
 —
 $

 Share of collaboration loss (1)

 $
 ( 1,230)
 $
 —
 $
 —
 $
 ( 3,323)
 $
 ( 4,553)

 Abecma U.S. Collaboration Profit/Loss Share

 March 31, 2023

 June 30, 2023

 September 30, 2023

 2seventy's share of profits (losses), net of 2seventy's share of BMS costs for commercial activities
 $
 21,581
 $
 23,272
 $
 ( 582)
 $
 1,366
 $
 45,637

 Reimbursement from BMS for 2seventy costs of commercial manufacturing and commercial activities
 1,380
 1,271
 1,118
 4,373

 Collaborative arrangement revenue (1)

 $
 22,961
 $
 24,543
 $
 $
 1,970
 $

 Share of collaboration loss (1)

 $
 —
 $
 —
 $
 —
 $
 —
 $
 —

 (1)As noted above, the calculation is performed on a quarterly basis and consists of 2seventy's share of profits, net of 2seventy's share of BMS costs for commercial activities, offset by reimbursement from BMS for 2seventy commercial activities. The calculation is independent of previous activity, which may result in fluctuations between revenue and expense recognition period over period. Collaborative arrangement revenue net of share of collaboration loss was $ 10.5 million and $ 50.0 million for the years ended December 31, 2024 and 2023, respectively.

 The following table summarizes the amounts associated with the research activities under the collaboration included in research and development expense or recognized as collaborative arrangement revenue for each quarter during the years ended December 31, 2024 and 2023 (in thousands):

 Abecma U.S. Collaboration Net R&D Expenses

 March 31, 2024

 June 30, 2024

 September 30. 2024

 2seventy's obligation for its share of BMS research and development expenses
 $
 ( 6,963)
 $
 ( 8,625)
 $
 ( 8,225)
 $
 ( 8,678)
 $
 ( 32,491)

 Reimbursement from BMS for 2seventy research and development expenses

 Net R&D expense (1)

 $
 ( 6,739)
 $
 ( 8,433)
 $
 ( 8,168)
 $
 ( 8,663)
 $
 ( 32,003)

 Abecma U.S. Collaboration Net R&D Expenses

 March 31, 2023

 June 30, 2023

 September 30. 2023

 2seventy's obligation for its share of BMS research and development expenses
 $
 ( 9,461)
 $
 ( 7,195)
 $
 ( 6,980)
 $
 ( 7,237)
 $
 ( 30,873)

 Reimbursement from BMS for 2seventy research and development expenses
 4,590
 1,543
 7,144

 Net R&D expense (1)

 $
 ( 4,871)
 $
 ( 5,652)
 $
 ( 6,120)
 $
 ( 7,086)
 $
 ( 23,729)

 (1)As noted above, the calculation is performed on a quarterly basis and consists of 2seventy's obligation for its share of BMS research and development expenses, offset by reimbursement from BMS for 2seventy research and development expenses.

 Ide-cel ex-U.S. Service Revenue
 The Company accounts for any ex-U.S. activities under the Amended Ide-cel CCPS pursuant to ASC 606. The following table summarizes the revenue recognized related to ide-cel ex-U.S. activities for the years ended December 31, 2024 and 2023 (in thousands). These amounts are reflected in service revenue in the consolidated statements of operations and comprehensive loss:

 For the years ended December 31,

 2024
 2023

 ASC 606 ide-cel license and manufacturing revenue – ex-U.S. (included as a component of service revenue) (1)

 $
 10,611
 $
 14,751

 (1)These amounts include reimbursements from BMS to the Company for the Company's ex-U.S. quality and other manufacturing costs associated with the manufacture of Abecma inventory.

 One-time restructuring expenses
 For the year ended December 31, 2024, the Company recognized one-time expense of $ 5.7 million representing its share of costs associated with BMS' early exit from a commercial manufacturing and supply agreement as a result of its transition to the use of suspension lentiviral vector in the manufacturing of Abecma. These costs are included in restructuring expenses on the consolidated statements of operations and comprehensive loss.
 Excess inventory write-off
 As of December 31, 2024, the Company and BMS performed an analysis of Abecma vector inventory on-hand and determined it was necessary to write-down excess vector inventory expected to expire prior to being used in the production of Abecma. This determination required estimation by management and BMS of future expected inventory requirements based on sales forecasts, as well as anticipated expiration dates based on current and projected stability data. If actual market conditions are less favorable than those projected by management and BMS, additional inventory write-downs may be required.
 As noted in Note 9, Commitments and contingencies, there is uncertainty around the final amount of the inventory write-down charge the Company will owe to BMS as the parties disagree on the portion of the charge attributed to the U.S. under the collaboration arrangement. Refer to Note 9 for additional details. The Company recorded the $ 11.8 million contingent liability in the fourth quarter of 2024, as part of the Company's share of collaboration loss for the period.

 Regeneron
 Upon closing of the Regeneron Transaction, on April 1, 2024, the Regeneron Collaboration Agreement described below was terminated, with certain provisions surviving. Please refer to Note 3, Asset Purchase Agreements for further information regarding the accounting treatment for the termination.
 Regeneron Collaboration Agreement
 In August 2018, bluebird bio entered into the "Regeneron Collaboration Agreement with Regeneron pursuant to which the parties will apply their respective technology platforms to the discovery, development, and commercialization of novel immune cell therapies for cancer. For additional information on the historical terms of this agreement, refer to the Company's 2023 Annual Report on 10-K.
 First Amendment to the Regeneron Collaboration Agreement
 In January 2023, 2seventy bio and Regeneron announced an amendment to the Regeneron Collaboration Agreement (the "Amendment"), to amend and extend their current agreement, applying their respective technology platforms to the discovery, development and commercialization of novel immune cell therapies for cancer. Under the Amendment, the parties identified four research targets to advance the next stage of research therapies. The parties continued sharing costs for these activities in a manner largely consistent with the existing agreement, with Regeneron covering 75 % of eligible late-stage research costs to study combinations and 100 % of the costs for the arms of clinical studies that included Regeneron agents through regulatory approval of two of the four targets. For other programs, cost-sharing followed the existing 50 / 50 cost sharing agreement.
 Additionally, Regeneron was to make one-time milestone payments for each of the first Clinical Candidate directed to MUC-16 and the first Clinical Candidate directed to a selected early stage research target to achieve the applicable milestones. Clinical Candidate milestone events and payments included:
 •$ 2.0 million payment from Regeneron for Development Candidate Nomination;
 •$ 3.0 million payment from Regeneron for IND Acceptance; and
 •$ 5.0 million payment from Regeneron for the earlier of (i) last patient dosed with a Monotherapy Regimen and (ii) dosing of the 10th patient in a Clinical Trial included in an Approved Research/ Development Plan.
 The Development Candidate Nomination for MUC-16 had already occurred and the corresponding milestone payment became due in the first quarter of 2024 upon the achievement of the Clinical Candidate milestone event (IND Acceptance) for MUC-16. The first milestone for MUC-16 was reduced to $ 1.0 million, in accordance with the terms of the first amendment, and the Company was paid a total of $ 4.0 million for the first two milestones related to MUC-16 during the year-ended December 31, 2024. This milestone payment is discussed further below.
 Regeneron Share Purchase Agreements
 A Share Purchase Agreement ("SPA") was entered into by bluebird bio and Regeneron in August 2018. In August 2018, on the closing date of the transaction, bluebird bio issued to Regeneron 0.4 million shares of bluebird bio's common stock, subject to certain restrictions, for $ 238.10 per share, or $ 100.0 million in the aggregate. Following the spin-off, Regeneron held approximately 0.1 million shares of 2seventy bio's common stock, subject to certain restrictions. The purchase price represents $ 63.0 million worth of common stock plus a $ 37.0 million premium, which represents a collaboration research advancement, or credit to be applied to Regeneron's initial 50 percent funding obligation for collaboration research, after which the collaborators will continue to fund ongoing research equally. The collaboration research advancement only applies to pre-IND research activities and is not refundable or creditable against post-IND research activities for any programs where Regeneron exercises its opt-in rights.
 In connection with the Amendment, the Company entered into a SPA with Regeneron pursuant to which the Company sold 1.1 million shares of its common stock, subject to certain restrictions, for $ 17.94 per share, to

 Regeneron for an aggregate cash price of approximately $ 20.0 million. The purchase price represents $ 9.9 million worth of common stock plus a $ 10.1 million premium, which represents deferred revenue.
 Accounting analysis
 Refer to the Company's 2023 Annual Report on Form 10-K for further discussion on accounting analysis and conclusions reached related to the 2018 Regeneron Collaboration Agreement.
 At the commencement of the Amendment, the Company identified two units of accounting, including the issuance of 1.1 million shares of 2seventy bio common stock and joint research activities under the amended agreement. The Company determined the total transaction price to be $ 20.0 million, which comprises $ 9.9 million of 2seventy bio equity sold to Regeneron and $ 10.1 million attributed to joint research activities. In determining the fair value of 2seventy bio common stock at closing, the Company considered the closing price of 2seventy bio common stock on the closing date of the transaction and included a lack of marketability discount because Regeneron received shares subject to certain restrictions.
 Consistent with the original Regeneron Collaboration Agreement, the Company assessed whether the joint research activities under the Amendment fell within the scope of ASC 808 and reassessed this throughout the life of the arrangement based on changes in the roles and responsibilities of the parties. Based on the terms of the amended arrangement as outlined above, for the collaboration research performed prior to submission of an IND application for a potential gene therapy product, both parties continued to be active participants in the collaboration. Both parties continued to perform research and development activities and shared in these costs through IND submission. Additionally, Regeneron and the Company continued to be exposed to significant risks and rewards dependent on the commercial success of any product candidates that may result from the collaboration. As such, the collaboration arrangement was deemed to be within the scope of ASC 808. The Company continues to apply ASC 606 by analogy to determine the measurement and recognition of the consideration received from Regeneron.
 The Company analogized to the contract modification guidance in ASC 606 to account for the scope and pricing changes contained in the Amendment. The Company concluded the four targets outlined in the joint research activities within the Amendment were now four distinct performance obligations. Based on this, the Company treated the modification as a termination of the existing contract and a creation of a new contract. The remaining premium of $ 1.1 million that had not been recognized as of December 31, 2022 was allocated with the $ 10.1 million premium attributed to joint research activities from the Amendment, for a total of $ 11.2 million. This amount was recognized through the filing of IND for each individual target, allocated among the four distinct performance obligations based on the stand-alone selling price of each target performance obligation. Future milestones continued to be fully constrained until such time as the achievement of such milestones were considered probable.
 The Company concluded that it continued to satisfy its obligations over-time as Regeneron received the benefit of the research activities as the activities were performed. The Company determined the most appropriate method to track progress towards completion of the four performance obligations was an input method that was based on costs incurred. There were significant judgments and estimates inherent in the determination of the costs to be incurred for the research and development activities related to the collaboration with Regeneron. These estimates and assumptions included a number of objective and subjective factors, including the likelihood that a target would be successfully developed through its IND filing and the estimated costs associated with such development, including the potential third-party costs related to each target's IND-enabling study. Any changes to these estimates would be recognized in the period in which they change as a cumulative catch-up.
 As noted, the four targets represented four distinct performance obligations and as such, the Company had allocated the total transaction price of $ 11.2 million among the four performance obligations based on the stand-alone selling price of each target.
 As of December 31, 2024, as the Regeneron Collaboration Agreement was terminated concurrently with the closing of the Regeneron Transaction, there is no unsatisfied portion of the transaction price remaining and there is no remaining deferred revenue. The remaining deferred revenue amount of $ 7.8 million as of April 1, 2024, was derecognized as part of the Regeneron Transaction. Refer to Note 3, Asset Purchase Agreements, for further detail.

 As discussed above, during the first quarter of 2024, the Company received a milestone payment of $ 4.0 million from Regeneron relating to IND acceptance for the MUC-16 target. As the filing of IND for the target was complete, the performance obligation relating to the target was satisfied and under ASC 606, the Company recognized the full $ 4.0 million as service revenue in the first quarter of 2024.
 The Regeneron Collaboration Agreement terminated concurrently with the closing of the Regeneron Transaction, and as such the Company did not recognize revenue in the second half of 2024. For the twelve months ended December 31, 2024, the Company recognized $ 4.7 million of collaborative arrangement revenue from the Regeneron Collaboration Agreement relating to the first quarter of 2024. For the twelve months ended December 31, 2023, the Company recognized $ 21.6 million of collaborative arrangement revenue.
 JW Therapeutics
 Please refer to Note 3, Asset Purchase Agreements, for further information on the terms of the Regeneron Transaction. Upon closing of the Regeneron Transaction on April 1, 2024, this program was assumed by Regeneron, including all upfront milestone and royalty payments to be made by JW (Cayman) Therapeutics Co., Ltd. ("JW"), if any.
 In October 2022, the Company entered into a strategic alliance with JW (Cayman) Therapeutics Co., Ltd. ("JW") to establish a translational and clinical cell therapy development platform designed to more rapidly explore T cell-based immunotherapy therapy products in the Chinese mainland, Hong Kong (China), and Macao (China). The initial focus of the collaboration is the Company's MAGE-A4 TCR program in solid tumors which is being developed as part of its collaboration with Regeneron.
 Under the terms of the agreement, the Company granted JW a license for the MAGE-A4 cell therapy in the Chinese mainland, Hong Kong (China), and Macao (China). JW is responsible for development, manufacturing, and commercialization of the initial product within China. The Company was eligible to receive milestones and royalties on product revenues in China. The Company and Regeneron were to equally share all payments received from JW, including but not limited to all upfront, milestone and royalty payments made by JW to the Company. The Company and Regeneron will also equally share all costs for any eligible expenses incurred in accordance with the terms of the Regeneron Collaboration Agreement. Additionally, the Company may leverage the early clinical data generated under the collaboration to support development in other geographies.
 Accounting Analysis - JW
 The Company concluded JW was a customer, and as such, the arrangement falls within the scope of Topic 606. Two performance obligations were identified within the contract consisting of (i) a license for the MAGE-A4 cell therapy, including a transfer of technology as agreed upon by both parties and (ii) vector supply necessary to conduct a Phase 1 clinical trial. The Company had concluded the manufacturing and supply of vector was a distinct performance obligation from the license for MAGE-A4 cell therapy because there were other vendors that could provide the necessary supply.
 At contract inception, the Company determined the unconstrained transaction price was $ 7.3 million, consisting of the $ 3.0 million up-front consideration and $ 4.3 million consisting of variable consideration for the reimbursement of vector supply. JW provided the Company with a $ 3.0 million upfront payment related to the granting of a license for MAGE-A4 cell therapy and the transfer of technology for the development of the Initial Product in which the Company shared equally with Regeneron. During the first quarter of 2023, the Company completed the full transfer of the license of IP related to MAGEA4 cell therapy along with the technology transfer, and as such, the upfront payment received from JW was recognized as service revenue during the first quarter of 2023. The transaction price of $ 4.3 million related to the supply of vector, consists of variable consideration based upon the estimated amount of vector needed in the development and commercialization for the initial Phase 1 clinical trial which the Company will also share equally with Regeneron. The agreement with JW was assumed by Regeneron as a part of the Regeneron Transaction. As of December 31, 2024, no unsatisfied portion of the variable consideration for the reimbursement of vector supply remains.
 Novo

 Upon the closing of an asset purchase agreement with Novo in June 2024, the Collaboration and License Agreement with Novo was terminated, with certain provisions surviving. Please refer to Note 3, Asset Purchase Agreements, for further information regarding the accounting treatment for the termination.
 Novo Collaboration and License Agreement
 In December 2021, the Company entered into a Collaboration and License Agreement (the "Novo Collaboration Agreement") with Novo Nordisk A/S ("Novo") for the discovery, development, and commercialization of a potential new gene therapy in hemophilia A. For additional information on the historical terms of this agreement and the related accounting analysis, refer to the Company's 2023 Annual Report on 10-K.
 In April 2023, the Company achieved positive proof of concept, preclinical data related to its joint research and development collaboration with Novo. This achievement triggered a $ 15.0 million milestone payment to the Company under the terms of the Novo Collaboration Agreement. Following the achievement of this milestone, Novo could elect to exercise an option to in-license technology from a third party in connection with the Novo Collaboration Agreement, for which the Company was responsible in making a $ 9.0 million payment to such third party. Novo exercised its option to in-license technology from a third party in connection with the Novo Collaboration Agreement, which triggered the $ 9.0 million payment by the Company to such third party. The remaining $ 6.0 million of the $ 15.0 million proof of concept milestone was allocated to the material right alongside a $ 5.0 million upfront payment. Prior to the Novo Transaction, the total $ 11.0 million is included in deferred revenue, current portion. This amount was derecognized as part of the accounting for the Novo Transaction. Please refer to Note 3, Asset Purchase Agreements, for further detail.
 Revenue associated with the research and development performance obligation were recognized as services were provided and costs were incurred. For the twelve months ended December 31, 2024, the Company recognized $ 3.5 million of service revenue under this agreement, relating to work completed during the first half of 2024. For the year ended December 31, 2023, the Company recognized $ 5.8 million of service revenue under this agreement. The collaboration terminated following the signing of the asset purchase agreement with Novo in June 2024. Refer to Note 3, Asset Purchase Agreements, for further details.

 12. Royalty and other revenue
 In May 2020, bluebird bio entered into a non-exclusive license agreement with Juno Therapeutics, Inc., a wholly-owned subsidiary of BMS, related to lentiviral vector technology to develop and commercialize CD-19-directed CAR T cell therapies. The agreement was assumed by the Company in connection with the separation. Royalty revenue recognized from sales of lisocabtagene maraleucel is included within royalty and other revenue in the consolidated statement of operations and comprehensive loss. As of August 24, 2023, the royalty term of this license agreement ended, and the Company will no longer receive royalties from sales of lisocabtagene maraleucel.
 The Company recognized no royalty and other revenue for the year ended December 31, 2024 and $ 4.6 million of royalty and other revenue in the year ended December 31, 2023.

 13. Intangible assets
 Intangible assets, net of accumulated amortization, are summarized as follows (in thousands):

 2024
 2023

 Cost
 Accumulated amortization
 Net
 Cost
 Accumulated amortization
 Net

 In-licensed rights
 $
 8,500
 $
 ( 2,615)
 $
 5,885
 $
 8,500
 $
 ( 1,906)
 $
 6,594

 Developed technology

 —
 —
 —
 30,100
 ( 30,100)
 —

 Total
 $
 8,500
 $
 ( 2,615)
 $
 5,885
 $
 38,600
 $
 ( 32,006)
 $
 6,594

 Amortization expense for intangible assets was $ 0.7 million and $ 0.7 million for the years ended December 31, 2024 and 2023, respectively.

 In-licensed rights
 In-licensed rights consist of capitalized milestone payments made to third parties upon receiving regulatory approval of Abecma in the U.S. The in-licensed rights are being amortized on a straight-line basis over the remaining life of the related patents of approximately twelve years, as the life of the related patents reflects the expected time period that the Company will benefit from the in-licensed rights.
 The following table summarizes the estimated future amortization for intangible assets for the next five years and thereafter (in thousands):

 As of December 31, 2024

 2025

 $

 2026

 2027

 2028

 2029

 2030 and thereafter

 2,345

 Total
 $
 5,885

 14. Stock-based compensation
 The Company's employees have historically participated in bluebird bio's various stock-based compensation plans.
 In connection with 2seventy's separation from bluebird bio on November 4, 2021, under the provisions of the existing plans, the outstanding bluebird bio equity awards were adjusted in accordance with the terms of the Employee Matters Agreement (equitable adjustment) to preserve the intrinsic value of the awards immediately before and after distribution. Refer to the Company's 2023 Annual Report on Form 10-K for additional detail related to the distribution.
 The Company has incurred compensation costs related to bluebird bio equity awards held by its employees but has not incurred compensation cost related to bluebird employees holding equity awards in 2seventy.
 In October 2021, the Company's board of directors adopted its 2021 Stock Option and Incentive Plan ("2021 Plan"), which was subsequently approved by bluebird bio, then the Company's sole stockholders. The 2021 Plan became effective on October 17, 2021, the day immediately prior to the effectiveness of the Company's Registration Statement on Form 10.
 The 2021 Plan allows for the granting of incentive stock options, non-qualified stock options, RSUs, PRSUs, and restricted stock awards to 2seventy bio's employees, members of the board of directors, and consultants of 2seventy bio, including those of 2seventy bio who became employees of the Company in connection with the separation. All awards granted under the 2021 Plan consist of shares of 2seventy bio's common stock.
 Stock-based compensation expense
 The Company recognized stock-based compensation expense totaling $ 12.2 million and $ 32.2 million during the years ended December 31, 2024 and 2023, respectively. The decrease in stock-based compensation expense is primarily the result of the Regeneron Transaction, under which a significant number of 2seventy employees became Regeneron employees upon closing, thus forfeiting their outstanding 2seventy equity awards.
 Stock-based compensation expense recognized by award type is as follows (in thousands):

 Year Ended December 31,

 2024
 2023

 Stock options
 $
 4,528
 $
 11,217

 Restricted stock units
 7,520
 20,607

 Employee stock purchase plan and other

 $
 $

 Stock-based compensation expense by classification included within the consolidated statements of operations and comprehensive loss was as follows (in thousands):

 Year Ended December 31,

 2024
 2023

 Research and development
 $
 2,070
 $
 12,508

 Selling, general and administrative
 9,043
 19,651

 1,037
 —

 $
 $

 As of December 31, 2024, the Company had $ 10.8 million, $ 15.4 million, and $ 0.0 million of unrecognized compensation expense related to unvested stock options, RSUs, and PRSUs, respectively, that is expected to be recognized over a weighted-average period of 2.2 years, 1.7 years, and 0.0 years, respectively.
 Stock options
 The fair value of each option issued to employees was estimated at the date of grant using the Black-Scholes option pricing model with the following weighted average assumptions:

 2024

 2023

 Expected volatility
 85.8
 %
 80.9
 %

 Expected term (in years)
 5.9

 Risk-free interest rate
 4.1
 %
 4.2
 %

 Expected dividend yield
 0.0
 %
 0.0
 %

 The following table summarizes the stock option activity under the Company's equity award plans for 2seventy employees:

 Shares
 Weighted-average exercise price per share
 Weighted-average contractual life (in years)
 Aggregate intrinsic value (a) (in thousands)

 Outstanding at December 31, 2023

 3,479
 $
 22.88

 Granted
 1,752
 $
 4.28

 Exercised
 ( 6)
 $
 3.97

 Cancelled or forfeited

 ( 1,458)
 $
 14.62

 Outstanding at December 31, 2024

 3,767
 $
 14.50
 8.12
 $

 Exercisable at December 31, 2024

 1,438
 $
 27.53
 7.07
 $
 —

 Vested and expected to vest at December 31, 2024

 3,767
 $
 14.50
 8.12
 $

 (a) The aggregate intrinsic value is calculated as the difference between the exercise price of the underlying options and the fair value of the common stock for the options that were in the money at December 31, 2024.

 Restricted stock units
 The following table summarizes the restricted stock unit activity under the Company's equity award plans for 2seventy employees:

 Shares
 Weighted-average grant date
fair value

 Unvested balance at December 31, 2023

 2,231
 $
 14.54

 Granted
 2,834
 4.11

 Vested
 ( 860)
 13.88

 Forfeited
 ( 686)
 11.70

 Unvested balance at December 31, 2024

 3,519
 $
 6.92

 The intrinsic value of RSUs vested during the year ended December 31, 2024 was $ 3.7 million.
 On February 1, 2021, the Company's former CEO was granted 27,000 PRSUs by bluebird bio. Each PRSU related to one share of common stock of bluebird bio. The number of PRSUs earned and vested would be determined based on bluebird bio's total shareholder return ("TSR") compared against the median TSR of a peer group over the performance period January 1, 2021 through December 31, 2023. Upon spin-off, the PRSUs were converted to 17,387 2seventy PRSUs. The TSR was kept whole by treating the value of bluebird bio at spin as a dividend that is reinvested into 2seventy stock. For the year ended December 31, 2023, the Company recognized $ 0.6 million of expense, respectively, related to the PRSUs. As of December 31, 2023, all expense related to the PRSUs had been recognized. Based on the comparison of bluebird bio's TSR from January 1, 2021 to the spin-off date and 2seventy's TSR from the spin-off date to December 31, 2023 to the median TSR of the peer group, the number of PRSUs earned and vested during the performance period was determined to be zero.
 Employee Stock Purchase Plan
 In October 2021, the Company's board of directors adopted its 2021 Employee Stock Purchase Plan ("2021 ESPP"), which was subsequently approved by bluebird bio, then its sole stockholder. The 2021 ESPP became effective on October 17, 2021, the day immediately prior to the effectiveness of the Company's Registration Statement on Form 10. The 2021 ESPP authorizes the initial issuance of a specified number of shares of the Company's common stock to participating employees. During each of the years ended December 31, 2024 and December 31, 2023, less than 0.1 million shares and 0.1 million shares of common stock were issued under the 2021 ESPP, respectively.

 15. Corporate restructuring
 2023 Restructuring Plan
 In August 2023, the Company's board of directors approved a restructuring plan (the "Restructuring Plan") to conserve financial resources and better align the Company's workforce with current business needs. As part of the Restructuring Plan, the Company's workforce was reduced by approximately 40 % in September 2023. The Company's 2023 Restructuring Plan was complete as of June 30, 2024.
 In connection with the Restructuring Plan, the Company incurred $ 8.6 million of one-time costs relating to severance and retention packages and related benefits. These costs were recognized in the third quarter of 2023, in accordance with ASC 420, Exit and Disposal Activities, and are included in Restructuring expenses in the

 consolidated statement of operations and comprehensive loss. All payments associated with the plan have been made and no accrued costs remain as of December 31, 2024.
 2024 Restructuring Plan
 In January 2024, the Company announced a strategic path forward to focus exclusively on the commercialization and development of Abecma. In connection with the Company's strategic re-alignment, the Company entered into an asset purchase agreement with Regeneron to sell the Company's oncology and autoimmune research and development programs, clinical manufacturing capabilities, and related platform technologies which closed on April 1, 2024. Approximately 62 % of the workforce that was left following completion of the 2023 Restructuring Plan transitioned to Regeneron as a part of the Regeneron Transaction. Additionally, as part of the strategic re-alignment, the Company's board of directors approved a restructuring plan (the "2024 Restructuring Plan") to further reduce its remaining workforce by approximately 14 %. The Company expects the 2024 Restructuring Plan to be substantially complete during the first half of 2025, as certain transition activities related to the Company's strategic re-alignment will extend into 2025.
 In connection with the 2024 Restructuring Plan, the Company expects to incur approximately $ 6.6 million of costs for severance and related benefits and stock-based compensation expense. These costs will be recognized through March 2025, and are disclosed as restructuring expenses on the consolidated statements of operations and comprehensive loss. The table below summarizes the expenses recognized and expected to be recognized under the 2024 Restructuring Plan as of December 31, 2024:

 Expense recognized for the twelve months ended December 31, 2024

 Total expense expected to be recognized

 Cash-related restructuring expenses:

 Severance and related benefits

 $
 5,547
 $
 5,582

 Non-cash expenses:

 Stock-based compensation expense

 1,037
 1,037

 Total restructuring expenses

 $
 6,584
 $
 6,619

 The following table summarizes the cash-related restructuring accrued liabilities activity recorded in connection with the 2024 Restructuring Plan for the twelve months ended December 31, 2024:

 For the twelve months ended December 31, 2024

 Beginning balance at January 1, 2024

 $
 —

 Cash-related expenses recognized

 5,548

 Cash-related expenses paid

 ( 4,943)

 Reversal of excess accrual

 —

 Remaining accrual at December 31, 2024 (1)

 $

 (1) This balance is included within accrued expenses and other current liabilities on the consolidated balance sheets.

 16. 401(k) Savings plan
 Upon spin-off from bluebird bio in 2021, 2seventy bio established a defined-contribution savings plan under Section 401(k) of the Internal Revenue Code ("2seventy 401(k) Plan"), which covers all employees who meet defined minimum age and service requirements, including those who became employees of the Company, and allows participants to defer a portion of their annual compensation on a pretax basis. Expense related to the 2seventy 401(k) Plans for 2seventy employees totaled $ 1.3 million and $ 3.1 million for the years ended December 31, 2024 and 2023, respectively.

 17. Income taxes
 The components of loss before income taxes were as follows (in thousands):

 2024

 2023

 Domestic
 $
 $

 Foreign
 —
 —

 Total
 $
 $

 The Company has not recorded a provision for federal or state income taxes as it has had cumulative net operating losses since inception.
 For the years ended December 31, 2024 and 2023, the Company did not recognize any income tax expense (benefit) as the Company was subject to a full valuation allowance. A reconciliation of income tax expense (benefit) computed at the statutory federal income tax rate to the Company's effective income tax rate as reflected in the financial statements is as follows:

 2024
 2023

 Federal income tax expense at statutory rate
 21.0
 %
 21.0
 %

 State income tax, net of federal benefit
 7.4
 %
 6.0
 %

 Permanent differences
 —
 %
 ( 0.2)
 %

 Goodwill

 —
 %
 ( 1.2)
 %

 ( 9.9)
 %
 ( 9.2)
 %

 Research and development credit
 2.4
 %
 5.3
 %

 Officer compensation limitation
 1.2
 %
 4.0
 %

 Uncertain tax positions
 ( 0.1)
 %
 ( 0.4)
 %

 Other
 ( 2.3)
 %
 0.7
 %

 Change in tax rate
 6.2
 %
 ( 1.8)
 %

 Change in valuation allowance
 ( 25.9)
 %
 ( 24.2)
 %

 Effective income tax rate (expense) benefit
 —
 %
 —
 %

 Deferred taxes are recognized for temporary differences between the basis of assets and liabilities for financial statement and income tax purposes. The significant components of the Company's deferred tax assets and liabilities are composed of the following (in thousands):

 2024
 2023

 Deferred tax assets:

 U.S. net operating loss carryforwards (federal and state)
 $
 61,734
 $
 38,685

 Tax credit carryforwards (federal and state)
 26,461
 24,933

 Capitalized license fees and research and development expenses
 9,496
 10,562

 Deferred revenue
 —
 5,015

 9,103
 11,834

 Lease liabilities
 64,960
 67,222

 Accruals and other
 1,056
 2,336

 Capitalized research and development expenses
 84,082
 88,721

 Total deferred tax assets
 256,892
 249,308

 Right-of-use assets
 ( 54,412)
 ( 57,087)

 Fixed assets
 ( 6,924)
 ( 11,499)

 Less: valuation allowance
 ( 195,556)
 ( 180,722)

 Net deferred taxes
 $
 —
 $
 —

 As of December 31, 2024, the Company had U.S. federal net operating loss carryforwards of approximately $ 228.0 million, which may be available to offset future income tax liabilities and which will carryforward indefinitely. As of December 31, 2024, the Company also had U.S. state net operating loss carryforwards of approximately $ 224.9 million, which may be available to offset future income tax liabilities and expire at various dates through 2044.
 As of December 31, 2024, the Company had federal research and development and orphan drug tax credit carryforwards of approximately $ 21.1 million, available to reduce future tax liabilities which expire at various dates through 2044. As of December 31, 2024, the Company also had U.S. state research and development carryforwards of approximately $ 9.3 million, which may be available to offset future income tax liabilities and expire at various dates through 2039. An analysis of the U.S. research and development and orphan drug credits has not yet been completed. Until a study is completed by the Company and any limitation is known, no amounts are being presented as an uncertain tax position.
 As of December 31, 2024, the Company is open to examination in the Internal Revenue Service and certain state tax authorities for all of the Company's tax years. The Company is in a position where net operating losses my potentially be utilized in future years to reduce taxable income. Although net operating loss and tax credit carryforwards generated prior to 2024 may still be adjusted upon examination by the Internal Revenue Service or state tax authorities if they have or will be used in a future period. Since the Company is in a loss carryforward position, it is generally subject to examination by the Internal Revenue Service and certain state tax authorities for all tax years in which a loss carryforward is available.
 Utilization of the net operating loss carryforwards and research and development tax credit carryforwards may be subject to an annual limitation under Section 382 of the Internal Revenue Code of 1986, as amended (the "Internal Revenue Code"), and corresponding provisions of state law, due to ownership changes that have occurred previously or that could occur in the future. These ownership changes may limit the amount of carryforwards that can be utilized annually to offset future taxable income. In general, an ownership change, as defined by Section 382, results from transactions increasing the ownership of certain shareholders or public groups in the stock of a corporation by more than 50 percent over a three-year period. The Company has not conducted a study to assess whether a change of control has occurred or whether there have been multiple changes of control since inception due to the significant complexity and cost associated with such a study. If the Company has experienced a change of

 control, as defined by Section 382, at any time since inception, utilization of the net operating loss carryforwards or research and development tax credit carryforwards would be subject to an annual limitation under Section 382, which is determined by first multiplying the value of the Company's stock at the time of the ownership change by the applicable long-term tax-exempt rate, and then could be subject to additional adjustments, as required. Any limitation may result in expiration of a portion of the net operating loss carryforwards or research and development tax credit carryforwards before utilization. Further, until a study is completed and any limitation is known, no amounts are being presented as an uncertain tax position.
 A valuation allowance is recorded against deferred tax assets if it is more likely than not that some or all of the deferred tax assets will not be realized. Due to the uncertainty surrounding the realization of the favorable tax attributes in future tax returns, the Company has recorded a full valuation allowance against the Company's otherwise recognizable net deferred tax assets. With respect to the period from separation through December 31, 2024, the valuation allowance increased on a net basis by approximately $ 14.8 million primarily due to capitalization of R&D expenses and current year losses generated.
 On December 22, 2017, the Tax Cuts and Jobs Act ("The TCJA") was signed into law. Under the TCJA provisions, effective with tax years beginning on or after January 1, 2022, taxpayers can no longer immediately expense qualified research and development expenditures, including all direct, indirect, overhead, and software development costs. Taxpayers are now required to capitalize and amortize these costs over five years for research conducted within the United States or 15 years for research conducted abroad. As a result, the Company capitalized $ 36.0 million of research and development expenses for the year ended December 31, 2024.
 The Company has no history of tax audits on a standalone basis and will regularly assess the outcome of potential examinations in each of the taxing jurisdictions when determining the adequacy of the amount of unrecognized tax benefit recorded.
 A reconciliation of the beginning and ending amount of unrecognized tax benefits is as follows (in thousands):

 Unrecognized tax benefits

 Balance as of December 31, 2022

 $

 Increases (decreases) for tax positions related to current period
 1,051

 Balance as of December 31, 2023

 1,800

 Increases (decreases) for tax positions related to current period

 Balance as of December 31, 2024

 $
 1,912

 The unrecognized tax benefits at December 31, 2024 are not material and, if recognized, would not affect the Company's effective tax rate due to its full valuation allowance position. The Company does not anticipate that the amount of existing unrecognized tax benefits will significantly increase or decrease within the next 12 months. The Company has elected to include interest and penalties related to uncertain tax positions as a component of its provision for income taxes. For the year ended December 31, 2024, the Company's accrued interest and penalties related to uncertain tax positions were no t material.

 18. Net loss per share
 The following common stock equivalents were excluded from the calculation of diluted net loss per share for the periods indicated because including them would have had an anti-dilutive effect (in thousands):

 2024

 2023

 Outstanding stock options (1)

 3,915
 3,678

 Restricted stock units

 3,519
 2,239

 Employee Stock Purchase Plan

 7,444
 5,998

 (1) Outstanding stock options include awards outstanding to employees of bluebird bio.

 19. Segment Reporting
 The Company, together with its wholly-owned subsidiaries, is a cell therapy company focused on the, development and commercialization of transformative treatments for cancer. The Company operates in a single segment, focusing on developing and commercializing potentially transformative treatments for cancer. The Company's reportable segment derives its revenues from its collaboration arrangement with BMS under which it is jointly developing and commercializing Abecma in the United States. The Company's Chief Executive Officer ("CEO") is its chief operating decision maker ("CODM") responsible for managing and allocating resources for the Company at a consolidated level. The Company's accounting policies associated with segment information are described in Note 2, Summary of significant accounting policies and basis of presentation, to the consolidated financial statements.
 The measure of segment profit or loss that the CODM uses to allocate resources and assess performance is the Company's consolidated net income (loss). The CODM uses consolidated net income (loss) to assess the segment's overall performance, with specific focus on the segment revenue and expenses associated with the Company's collaboration with BMS for Abecma. Following the adoption of ASU 2023-07, the Company is required to disclose

 significant segment expenses that are regularly provided to the CODM. The table below includes information about the Company's segment, including segment expenses, and a reconciliation to net income (loss).

 2024
 2023

 Revenue:

 Abecma collaboration revenue (1)

 $
 $

 Other revenue (2)

 22,814
 50,377

 Total revenue:

 37,862
 100,387

 Operating expenses:

 Abecma net research and development (1)

 32,003
 23,729

 Abecma cost of manufacturing

 18,010
 14,819

 Abecma share of collaboration loss (1)

 4,553
 —

 Other research and development (3)

 28,445
 148,517

 Net rent expense

 15,547
 43,427

 Infrastructure and support functions

 26,639
 42,054

 Restructuring costs

 12,303
 8,614

 Other segment expenses (4)

 15,791
 56,835

 Non-operating expenses:

 Interest income, net

 10,874
 12,413

 Other income

 4,347
 7,625

 Gain/loss on sale of assets

 42,961
 —

 Income tax expense

 —
 —

 Segment and consolidated net loss

 $
 $

 (1)Refer to Note 11, Collaborative arrangements and strategic partnerships, for the individual components of these amounts reviewed by the CODM in conjunction with the information above.
 (2)Refer to Note 11, Collaborative arrangements and strategic partnerships, for more information on other revenue recognized under the Company's collaborations with Regeneron and Novo, both of which terminated during 2024 upon the closing of Regeneron and Novo Transactions, respectively.
 (3)Consists of pipeline spend incurred in the first half of 2024 prior to the close of the Regeneron and Novo transactions.
 (4) Other segment expenses include cost of royalty and other revenue, change in fair value of contingent consideration, goodwill impairment charge, depreciation and amortization, and stock-based compensation expense.

 20. Subsequent events
 On March 10, 2025, the Company, BMS, and Daybreak Merger Sub Inc., a wholly owned subsidiary of BMS ("Merger Sub"), entered into an Agreement and Plan of Merger (the "BMS Merger Agreement"). Pursuant to the BMS Merger Agreement, and upon the terms and subject to the conditions therein, Merger Sub will commence a cash tender offer (the "Offer") to acquire all of the issued and outstanding shares of common stock, par value $ 0.0001 per share, of the Company ("Company Common Stock"), at a price per share of $ 5.00, without interest and subject to any withholding of taxes required by applicable law. The Offer will initially expire at one minute after 11:59 p.m. Eastern Time on the date that is 20 business days following the commencement of the Offer, subject to extension under certain circumstances.
 Merger Sub's obligation to accept for payment shares of Company Common Stock validly tendered pursuant to the Offer is subject to the satisfaction or waiver, to the extent permitted under applicable legal requirements, of certain conditions set forth in the BMS Merger Agreement, including that (i) there shall have been validly tendered and not validly withdrawn at or prior to the expiration of the Offer that number of shares of Company Common Stock that, considered together with all other shares of Company Common Stock beneficially owned by BMS and its

 controlled affiliates, represent one more than 50 % of the total number of shares of Company Common Stock issued and outstanding at the time of expiration of the Offer; (ii) any consent, approval or clearance with respect to, or terminations or expiration of any applicable mandatory waiting period (and any extensions thereof) applicable to the Offer or the Merger under the Hart-Scott-Rodino Antitrust Improvements Act of 1976, as amended, shall have been received or expired or been terminated; (iii) no order or injunction preventing the consummation of the Offer or the Merger (as defined below) shall have been issued by any governmental entity of competent jurisdiction, and there shall have been no law in effect enacted by a governmental entity of competent jurisdiction making consummation of the Offer or the Merger illegal; (iv) the representations and warranties of the Company contained in the BMS Merger Agreement shall be true and correct, subject to customary materiality thresholds and exceptions; (v) the Company shall have performed or complied in all material respects with its obligations or covenants contained in the BMS Merger Agreement; (vi) since the date of the BMS Merger Agreement there shall not have occurred a Company Material Adverse Effect (as defined in the BMS Merger Agreement); and (vii) other customary conditions.
 Following the consummation of the Offer, upon the terms and subject to the conditions set forth in the BMS Merger Agreement, and in accordance with the DGCL, Merger Sub will merge with and into the Company, with the Company continuing as the surviving corporation and as a wholly owned subsidiary of BMS (the "Merger"). The Merger will be governed by Section 251(h) of the DGCL, with no stockholder vote required in order to consummate the Merger. The closing of the transaction is expected to occur in the second quarter of 2025.
 Pursuant to the BMS Merger Agreement, at the effective time of the Merger (the "Effective Time"), by virtue of the Merger and without any action on the part of any holder of shares of Company Common Stock, each share of Company Common Stock (other than shares of Company Common Stock (a) held in the treasury of the Company, (b) that as of immediately prior to the Effective Time were owned by BMS or Merger Sub or any of their direct or indirect subsidiaries, (c) irrevocably accepted for payment in the Offer, or (d) with respect to which the holders thereof have properly exercised and perfected demands for appraisal in accordance with Section 262 of the DGCL) will be automatically cancelled and converted into the right to receive $ 5.00 in cash, without interest (the "Merger Consideration").
 In addition, immediately prior to the Effective Time, by virtue of the Merger and without any action on the part of any holder thereof, (i) each option to purchase shares of Company Common Stock (a "Company Option"), whether vested or unvested, that is outstanding and unexercised and has a per share exercise price that is less than the Merger Consideration shall fully vest, be cancelled and automatically converted into the right to receive for each share of Company Common Stock underlying such Company Option, subject to deduction for any required withholding for applicable taxes, an amount in cash from BMS or the surviving corporation equal to the excess of the Merger Consideration over the per share exercise price of such Company Option, (ii) each Company Option, whether vested or unvested, that is outstanding and unexercised and has a per share exercise price that is equal to or greater than the Merger Consideration shall be automatically cancelled for no consideration and (iii) each outstanding and unsettled restricted stock unit award with respect to shares of Company Common Stock (a "Company RSU") that is outstanding, whether vested or unvested, shall fully vest, be cancelled and automatically converted into the right to receive, subject to deduction for any required withholding for applicable taxes, an amount in cash from BMS or the surviving corporation equal to the number of shares of Company Common Stock underlying such Company RSU multiplied by the Merger Consideration.
 Further, as of the Effective Time, each of the pre-funded warrants to purchase shares of Company Common Stock issued by the Company pursuant to that certain Assumption Agreement dated November 3, 2021, between the Company and bluebird bio, Inc. (a "Company Pre-Funded Warrant") that is outstanding and unexercised shall, in accordance with its terms, automatically and without any required action on the part of the holder thereof, cease to represent a warrant exercisable for shares of Company Common Stock and shall receive an amount of cash equal to the product of (a) the aggregate number of shares of Company Common Stock underlying such Company Pre-Funded Warrant, after taking into account such Company Pre-Funded Warrant's "cashless exercise" provisions, and (b) the Merger Consideration, without interest and subject to deduction for any required withholding for applicable taxes.

 The BMS Merger Agreement includes customary representations, warranties and covenants of the Company, BMS and Merger Sub for a transaction of this nature, including covenants regarding the operation of the Company's business prior to the Effective Time.
 The Company has agreed to customary "no-shop" restrictions on its ability to solicit alternative acquisition proposals from third parties and engage in discussions or negotiations with third parties regarding acquisition proposals. Notwithstanding these restrictions, the Company may under certain circumstances provide information to and participate in discussions or negotiations with third parties with respect to an unsolicited bona fide written Acquisition Proposal (as such term is defined in the BMS Merger Agreement) that the board of directors of the Company (the "Company Board") has determined constitutes or would reasonably be expected to lead to a Superior Proposal (as such term is defined in the BMS Merger Agreement) and that the failure to take such action would be inconsistent with the Company Board's fiduciary obligations to the Company's stockholders under applicable law.
 The BMS Merger Agreement also provides that, in connection with the termination of the BMS Merger Agreement under certain specified circumstances, including termination by the Company to accept and enter into an agreement with respect to a Superior Proposal, the Company will be required to pay BMS a termination fee in the amount of $ 10.0 million.
 The foregoing description of the BMS Merger Agreement is only a summary of certain material provisions thereof, does not purport to be complete. The full text of the BMS Merger Agreement is filed as Exhibit 2.1 to this Annual Report on Form 10-K.

 EXHIBIT INDEX

 Exhibit Number
 Exhibit Description

 2.1***

 Agreement and Plan of Merger, dated as of March 10, 2025, by and among Bristol-Myers Squibb Company, Daybreak Merger Sub Inc. and 2seventy bio, Inc. (incorporated by reference to Exhibit 2.1 to Current Report on Form 8-K filed on March 11, 2015.

 3.1

 Amended and Restated Certificate of Incorporation of 2seventy bio, Inc. (incorporated by reference to Exhibit 3.1 to Current Report on Form 8-K filed on November 4, 2021).

 3.2

 Amended and Restated Bylaws of 2seventy bio, Inc. (incorporated by reference to Exhibit 3.2 to Annual Report on Form 10-K filed on March 16, 2023).

 4.1

 Form of Pre-Funded Warrant (incorporated by reference to Exhibit 10.7 to Current Report on Form 8-K filed on November 4, 2021).

 4.2

 Description of Securities (incorporated by reference to Exhibit 4.4 to Annual Report on Form 10-K filed on March 22, 2022).

 10.1#

 2seventy bio, Inc. 2021 Employee Stock Purchase Plan (incorporated by reference to Exhibit 99.2 to Form S-8 filed on November 1, 2021).

 10.2#

 2seventy bio, Inc. 2021 Stock Option and Incentive Plan, and forms of award agreement thereunder (incorporated by reference to Exhibit 99.1 to Form S-8 filed on November 1, 2021).

 10.3#

 2seventy bio, Inc. Senior Executive Cash Incentive Bonus Plan (incorporated by reference to Exhibit 10.3 to Annual Report on Form 10-K filed on March 22, 2022).

 10.4

 2seventy bio, Inc. Non-Employee Director Compensation Policy (incorporated by reference to Exhibit 10.4 to Annual Report on Form 10-K filed on March 22, 2022).

 10.5#

 Form of Indemnification Agreement between 2seventy bio, Inc. and individual directors (incorporated by reference to Exhibit 10.6 to Form 10 filed on October 8, 2021).

 10.6

 Lease, dated September 21, 2015, by and between bluebird bio, Inc. and ARE-MA Region No. 40 LLC (incorporated by reference to Exhibit 10.22 to Form 10 filed on October 8, 2021).

 10.7

 First Amendment to Lease, dated June 21, 2016, by and between bluebird bio, Inc. and ARE-MA Region No. 40 LLC (incorporated by reference to Exhibit 10.23 to Form 10 filed on October 8, 2021).

 10.8

 Second Amendment to Lease, dated November 14, 2016, by and between bluebird bio, Inc. and ARE-MA Region No. 40 LLC (incorporated by reference to Exhibit 10.24 to Form 10 filed on October 8, 2021).

 10.9

 Patent License Agreement, dated August 31, 2015, by and between bluebird bio, Inc. and the National Institutes of Health (incorporated by reference to Exhibit 10.3 to Quarterly Report on Form 10-Q filed on May 12, 2022).

 10.10

 Amendment to License Agreement, dated April 25, 2022, by and between 2seventy bio, Inc. and the National Institutes of Health (incorporated by reference to Exhibit 10.4 to Quarterly Report on Form 10-Q filed on May 12, 2022).

 10.11

 Second Amendment to License Agreement, dated January 16, 2024, by and between 2seventy bio, Inc. and the National Institutes of Health (incorporated by reference to Exhibit 10.14 to Annual Report on Form 10-K filed on March 7, 2024).

 10.12

 Form of Registration Rights Agreement, dated March 15, 2022, by and between 2seventy bio, Inc. and purchasers in the March 2022 private placement (incorporated by reference to Exhibit 10.2 to Current Report on Form 8-K filed on March 16, 2022).

 10.13

 Amended and Restated License Agreement by and between bluebird bio, Inc. and Celgene Corporation, dated February 16, 2016 (incorporated by reference to Exhibit 10.14 to Form 10 filed on October 8, 2021).

 10.14

 Second Amended and Restated License Agreement by and between bluebird bio, Inc. and Celgene Corporation and Celgene European Investment Company LLC, dated May 8, 2020 (incorporated by reference to Exhibit 10.15 to Form 10 filed on October 8, 2021).

 10.15

 License Agreement, dated August 13, 2014, by and between bluebird bio, Inc. and Biogen Idec MA Inc. (incorporated by reference to Exhibit 10.17 to Annual Report on Form 10-K filed on March 22, 2022).

 10.16

 Assumption Agreement by and between 2seventy bio, Inc. and bluebird bio, Inc. with respect to Securities Purchase Agreement, dated September 7, 2021, by and among bluebird bio, Inc. and the institutional investors named therein, and Registration Rights Agreement, dated September 7, 2021, by and among bluebird bio, Inc. and the persons listed on the attached Schedule A thereto (incorporated by reference to Exhibit 10.21 to Form 10 filed on October 8, 2021).

 10.17

 Tax Matters Agreement, dated as of November 3, 2021, by and between bluebird bio, Inc. and 2seventy bio, Inc. (incorporated by reference to Exhibit 10.1 to Current Report on Form 8-K filed on November 4, 2021).

 10.18

 Intellectual Property License Agreement, dated as of November 3, 2021, by and between bluebird bio, Inc. and 2seventy bio, Inc. (incorporated by reference to Exhibit 10.3 to Current Report on Form 8-K filed on November 4, 2021).

 10.19

 Employee Matters Agreement, dated as of November 3, 2021, by and between bluebird bio, Inc. and 2seventy bio, Inc. (incorporated by reference to Exhibit 10.2 to Current Report on Form 8-K filed on November 4, 2021).

 10.20

 Transition Services Agreement, dated as of November 3, 2021, by and between bluebird bio, Inc. and 2seventy bio, Inc. (incorporated by reference to Exhibit 10.4 to Current Report on Form 8-K filed on November 4, 2021).

 10.21

 Transition Services Agreement, dated as of November 3, 2021, by and between 2seventy bio, Inc. and bluebird bio, Inc. (incorporated by reference to Exhibit 10.5 to Current Report on Form 8-K filed on November 4, 2021).

 10.22

 Second Amendment to Amended and Restated Co-Development, Co-Promote and Profit Share Agreement, between 2seventy bio, Inc., Celgene Corporation and Celgene Investment Company LLC, dated June 23, 2023 (incorporated by reference to Exhibit 10.1 to Quarterly Report on Form 10-Q filed on August 14, 2023).

 10.23

 Asset Purchase Agreement between 2seventy bio, Inc. and Regeneron Pharmaceuticals, Inc., dated as of January 29, 2024 (incorporated by reference to Exhibit 10.1 to Quarterly Report on Form 10-Q filed on March 31, 2024).

 10.24#

 Amended and Restated Transitional Services Agreement between 2seventy bio, Inc. and Nick Leschly, dated as of March 29, 2024 (incorporated by reference to Exhibit 10.1 to Current Report on Form 8-K filed on April 1, 2024).

 10.25*#

 Executive Employment Agreement between 2seventy bio, Inc. and William Baird, dated as of January 6, 2025.

 10.26*#

 Executive Employment Agreement between 2seventy bio, Inc. and Victoria Eatwell, dated as of January 6, 2025.

 10.27*#

 Executive Employment Agreement between 2seventy bio, Inc. and Jessica Snow, dates as of January 6, 2025.

 10.28*#

 Release and Equity Agreement, by and between 2seventy bio, Inc. and Philip Gregory (incorporated by reference to Exhibit 10.1 to Current Report on Form 8-K filed on March 18, 2024).

 10.29

 Asset Purchase Agreement between 2seventy bio, Inc. and Novo Nordisk A/S, dated as of June 21, 2024 (incorporated by reference to Exhibit 10.1 to Quarterly Report on Form 10-Q filed on August 8, 2024).

 19.1

 Insider Trading Policy (incorporated by reference to Exhibit 19.1 to Annual Report on Form 10-K filed March 7, 2024).

 21.1

 Subsidiaries of the Registrant (incorporated by reference to Exhibit 21.1 to Annual Report on Form 10-K filed March 16, 2023).

 23.1*

 Consent of Ernst & Young LLP, Independent Registered Public Accounting Firm.

 31.1*

 Certification of Principal Executive Officer Pursuant to Rules 13a-14(a) and 15d-14(a) under the Securities Exchange Act of 1934, as Adopted Pursuant to Section 302 of the Sarbanes-Oxley Act of 2002.

 31.2*

 Certification of Principal Financial Officer Pursuant to Rules 13a-14(a) and 15d-14(a) under the Securities Exchange Act of 1934, as Adopted Pursuant to Section 302 of the Sarbanes-Oxley Act of 2002.

 32.1**

 Certification of Principal Executive Officer and Principal Financial Officer Pursuant to 18 U.S.C. Section 1350, as Adopted Pursuant to Section 906 of the Sarbanes-Oxley Act of 2002.

 97.1#

 Compensation Recovery Policy, effective as of September 26, 2023 (incorporated by reference to Exhibit 97.1 to Annual Report on Form 10-K filed March 7, 2024).

 101.INS*

 101.SCH*

 101.CAL*

 101.DEF*

 101.LAB*

 101.PRE*

 104*

 * Filed herewith.
 **The certifications furnished in Exhibit 32.1 and 32.2 hereto are deemed to accompany this Annual Report on Form 10-K and will not be deemed "filed" for purposes of Section 18 of the Securities Exchange Act of 1934, as amended. Such certifications will not be deemed to be incorporated by reference into any filings under the Securities Act of 1933, as amended, or the Securities Exchange Act of 1934, as amended, except to the extent that the Registrant specifically incorporates it by reference.
 # Indicates a management contract or compensatory plan, contract or arrangement.
 Portions of this exhibit (indicated by asterisks) were omitted in accordance with the rules of the Securities and Exchange Commission.
 *** Schedules and exhibits have been omitted pursuant to Item 601(b)(2) of Regulation S-K. 2seventy bio agrees to furnish supplementally a copy of any such schedule or exhibit to the SEC upon request.

 SIGNATURES
 Pursuant to the requirements of Section 13 or 15(d) of the Securities Exchange Act of 1934, as amended, the Registrant has duly caused this Annual Report on Form 10-K to be signed on its behalf by the undersigned, thereunto duly authorized.

 Date: March 25, 2025

 By: /s/ William Baird

 William Baird

 President and Chief Executive Officer

 Each person whose individual signature appears below hereby authorizes and appoints William D. Baird and Victoria Eatwell, and each of them, with full power of substitution and resubstitution and full power to act without the other, as his or her true and lawful attorney-in-fact and agent to act in his or her name, place and stead and to execute in the name and on behalf of each person, individually and in each capacity stated below, and to file any and all amendments to this annual report on Form 10-K and to file the same, with all exhibits thereto, and other documents in connection therewith, with the Securities and Exchange Commission, granting unto said attorneys-in-fact and agents, and each of them, full power and authority to do and perform each and every act and thing, ratifying and confirming all that said attorneys-in-fact and agents or any of them or their or his substitute or substitutes may lawfully do or cause to be done by virtue thereof.
 Pursuant to the requirements of the Securities Exchange Act of 1934, as amended, this Annual Report on Form 10-K has been signed below by the following persons on behalf of the Registrant in the capacities and on March 25, 2025.

 SIGNATURE
 TITLE

 /s/ William Baird

 President and Chief Executive Officer (Principal Executive Officer and Duly Authorized Officer)

 William Baird

 /s/ Victoria Eatwell

 Chief Financial Officer (Principal Financial and Accounting Officer)

 Victoria Eatwell

 /s/ Nick Leschly

 Chair of the Board

 Nick Leschly

 /s/ Sarah Glickman

 Sarah Glickman

 /s/ Denice Torres

 Denice Torres

 /s/ Marcela Maus, M.D., Ph. D.

 Marcela Maus, M.D., Ph. D.

 /s/ Wei Lin, M.D.

 Wei Lin, M.D.

 /s/ Eli Casdin

 Eli Casdin

 /s/ Charles Newton

 Charles Newton