tsvt-20240331

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 10-Q


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

For the quarterly period ended March 31, 2024


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

For the transition period from _________ to ________

Commission file number 001-40791

2seventy bio, Inc.

(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 No.)
60 Binney Street Cambridge, MA						02142
(Address of principal executive offices)						(Zip Code)

(617) 675-7270

(Registrant's telephone number, including area code)

(Former name, former address and former fiscal year, if changed since last report)

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


Title of each class	Trading Symbol(s)	Name of each exchange on which registered
Common Stock, par value $0.0001 per share	TSVT	The Nasdaq Stock Market LLC

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 is a shell company (as defined in Rule 12b-2 of the Act). Yes ☐ No ☒

The registrant had outstanding 51,405,419 shares of common stock as of May 03, 2024.

TABLE OF CONTENTS


		Page
Part I- Financial Information
Item 1.	Condensed Consolidated Balance Sheets as of March 31, 2024 and December 31, 2023	1
	Condensed Consolidated Statements of Operations and Comprehensive Loss for the Three Months Ended March 31, 2024 and March 31, 2023	2
	Condensed Consolidated Statements of Stockholders’ Equity for the Three Months Ended March 31, 2024 and March 31, 2023	3
	Condensed Consolidated Statements of Cash Flows for the Three Months Ended March 31, 2024 and March 31, 2023	4
	Notes to Condensed Consolidated Financial Statements	5
Item 2.	Management's Discussion and Analysis of Financial Condition and Results of Operations	26
Item 3.	Quantitative and Qualitative Disclosures About Market Risk	39
Item 4.	Controls and Procedures	40
	Part II. Other Information
Item 1	Legal Proceedings	41
Item 1A.	Risk Factors	41
Item 2.	Unregistered Sales of Equity Securities and Use of Proceeds	41
Item 3.	Defaults Upon Senior Securities	41
Item 4.	Mine Safety Disclosures	41
Item 5.	Other Information	41
Item 6.	Exhibit Index	42
	Signatures	44

CAUTIONARY STATEMENT CONCERNING FORWARD-LOOKING STATEMENTS

This Quarterly Report on Form 10-Q and other materials we have filed or will file with the SEC include, or will include, forward-looking statements. All statements in this Quarterly Report on Form 10-Q, in other materials we have filed or will file with the SEC and in related comments by our management, other than statements of historical facts, including statements about future events, future financial position, business strategy, budgets, projected costs, plans and objectives of management for future operations, are forward-looking statements that involve certain risks and uncertainties. Use of the words “may,” “will,” “would,” “could,” “should,” “believes,” “estimates,” “projects,” “potential,” “expects,” “plans,” “seeks,” “intends,” “evaluates,” “pursues,” “anticipates,” “continues,” “designs,” “impacts,” “affects,” “forecasts,” “target,” “outlook,” “initiative,” “objective,” “designed,” “priorities,” “goal” or the negative of those words or other similar expressions may identify forward-looking statements that represent our current judgment about possible future events, but the absence of these words does not necessarily mean that a statement is not forward-looking.

Forward-looking statements are based on our current expectations and assumptions regarding our business, the economy and other future conditions. Because forward-looking statements relate to the future, by their nature, they are subject to inherent uncertainties, risks and changes in circumstances that are difficult to predict. As a result, our actual results may differ materially from those contemplated by the forward-looking statements. Important factors that could cause actual results to differ materially from those in the forward-looking statements include regional, national or global political, economic, business, competitive, market and regulatory conditions and the following:

•our and Bristol Myers Squibb’s, or BMS, plans for the continued commercialization of Abecma and the development and commercialization of earlier lines of therapy;

•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 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, clinical manufacturing capabilities, and related platform technologies to Regeneron Pharmaceuticals, Inc., or Regeneron, which we refer to as the Asset Sale;

•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 needs 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;

•the potential benefits of strategic collaboration agreements;

•potential indemnification liabilities we may owe to bluebird bio after the separation;

•the impact of inflation rates on our business, financial condition and results of operation;

•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. Although we have attempted to identify important risk factors, there may be other risk factors not presently known to us or that we presently believe are not material that could cause actual results and developments to differ materially from those made in or suggested by the forward-looking statements contained in this Quarterly Report on Form 10-Q. If any of these risks materialize, or if any of the above assumptions underlying forward-looking statements prove incorrect, actual results and developments may differ materially from those made in or suggested by the forward-looking statements contained in this Quarterly Report on Form 10-Q. For the reasons described above, we caution you against relying on any forward-looking statements, which should also be read in conjunction with the other cautionary statements that are included elsewhere in this Quarterly Report on Form 10-Q. Any forward-looking statement made by us in this Quarterly Report on Form 10-Q speaks only as of the date thereof. Factors or events that could cause our actual results to differ may emerge from time to time, and it is not possible for us to predict all of them. We undertake no obligation to publicly update or to revise any forward-looking statement, whether as a result of new information, future developments, or otherwise, except as may be required by law.

PART I. FINANCIAL INFORMATION

Item 1. Financial Information

2seventy bio, Inc.

Condensed Consolidated Balance Sheets

(unaudited)

(in thousands, except par value amounts)


	As of March 31, 2024		As of December 31, 2023
Assets
Current assets:
Cash and cash equivalents	$	56,792	$	74,958
Marketable securities	124,590		142,031
Assets held for sale	12,786		—
Prepaid expenses	6,697		7,365
Receivables and other current assets	11,977		13,411
Total current assets	212,842		237,765
Property, plant and equipment, net	38,234		58,150
Marketable securities	—		4,816
Intangible assets, net	6,417		6,594
Operating lease right-of-use assets	215,317		219,958
Restricted investments and other non-current assets	38,241		38,143
Total assets	$	511,051	$	565,426
Liabilities and Stockholders’ Equity
Current liabilities:
Accounts payable	$	8,801	$	6,028
Accrued expenses and other current liabilities	22,263		25,688
Operating lease liability, current portion	13,006		12,660
Deferred revenue, current portion	16,336		15,403
Total current liabilities	60,406		59,779
Deferred revenue, net of current portion	2,450		3,918
Operating lease liability, net of current portion	240,071		244,013
Other non-current liabilities	685		2,416
Total liabilities	303,612		310,126
Commitments and contingencies (Note 8)
Stockholders’ equity:
Preferred stock, $0.0001 par value; 10,000 shares authorized, 0 shares issued and outstanding at March 31, 2024 and December 31, 2023	—		—
Common stock, $0.0001 par value; 200,000 shares authorized, 51,404 and 50,632 shares issued and outstanding at March 31, 2024 and December 31, 2023, respectively	5		5
Additional paid-in capital	771,660		766,716
Accumulated other comprehensive loss	(336)		(204)
Accumulated deficit	(563,890)		(511,217)
Total stockholders’ equity	207,439		255,300
Total liabilities and stockholders’ equity	$	511,051	$	565,426

See accompanying notes to unaudited condensed consolidated financial statements.

2seventy bio, Inc.

Condensed Consolidated Statements of Operations and Comprehensive Loss

(unaudited)

(in thousands, except per share data)


	For the three months ended March 31,
	2024		2023
Revenue:
Service revenue	$	7,721	$	10,826
Collaborative arrangement revenue	4,714		29,372
Royalty and other revenue	—		1,423
Total revenues	12,435		41,621
Operating expenses:
Research and development	43,931		68,246
Cost of manufacturing for commercial collaboration	3,269		3,654
Selling, general and administrative	12,659		20,720
Share of collaboration loss	1,230		—
Restructuring expenses	4,230		—
Cost of royalty and other revenue	—		641
Change in fair value of contingent consideration	(1,730)		73
Total operating expenses	63,589		93,334
Loss from operations	(51,154)		(51,713)
Interest income, net	2,861		2,049
Other income, net	646		2,643
Loss on assets held for sale	(5,026)		—
Loss before income taxes	(52,673)		(47,021)
Income tax (expense) benefit	—		—
Net loss	$	(52,673)	$	(47,021)
Net loss per share - basic and diluted	$	(1.01)	$	(1.08)
Weighted-average number of common shares used in computing net loss per share - basic and diluted	52,071		43,468
Other comprehensive (loss) income:
Other comprehensive (loss) income, net of tax benefit (expense) of $0.0 million and $0.0 million for the three months ended March 31, 2024 and 2023, respectively.	$	(132)	$	927
Total other comprehensive (loss) income	$	(132)	$	927
Comprehensive loss	$	(52,805)	$	(46,094)

See accompanying notes to unaudited condensed consolidated financial statements.

2seventy bio, Inc.

Condensed Consolidated Statements of Stockholders’ Equity

(unaudited)

(in thousands)


	Common stock			Additional paid-in capital		Accumulated other comprehensive loss		Accumulated deficit		Total stockholders’ equity
	Shares	Amount
Balances at December 31, 2023	50,632	$	5	$	766,716	$	(204)	$	(511,217)	$	255,300
Vesting of restricted stock units	695	—		—		—		—		—
Exercise of stock options	—	—		—		—		—		—
Stock-based compensation	—	—		4,684		—		—		4,684
Purchases of shares under ESPP	77	—		260		—		—		260
Other comprehensive loss	—	—		—		(132)		—		(132)
Net loss	—	—		—		—		(52,673)		(52,673)
Balances at March 31, 2024	51,404	$	5	$	771,660	$	(336)	$	(563,890)	$	207,439


	Common stock			Additional paid-in capital		Accumulated other comprehensive loss		Accumulated deficit		Total stockholders’ equity
	Shares	Amount
Balances at December 31, 2022	37,928	$	4	$	606,986	$	(2,877)	$	(293,647)	$	310,466
Vesting of restricted stock units	237	—		—		—		—		—
Exercise of stock options	1	—		7		—		—		7
Issuance of common stock in public offering, net of issuance costs	10,870	1		116,968		—		—		116,969
Issuance of common stock to Regeneron	1,115	—		9,859		—		—		9,859
Stock-based compensation	—	—		9,666		—		—		9,666
Purchases of shares under ESPP	39	—		451		—		—		451
Other comprehensive income	—	—		—		927		—		927
Net loss	—	—		—		—		(47,021)		(47,021)
Balances at March 31, 2023	50,190	$	5	$	743,937	$	(1,950)	$	(340,668)	$	401,324

See accompanying notes to unaudited condensed consolidated financial statements.

2seventy bio, Inc.

Condensed Consolidated Statements of Cash Flows

(unaudited)

(in thousands)


	For the three months ended March 31,
	2024		2023
Cash flows from operating activities:
Net loss	$	(52,673)	$	(47,021)
Adjustments to reconcile net loss to net cash used in operating activities:
Change in fair value of contingent consideration	(1,730)		73
Depreciation and amortization	2,107		2,255
Stock-based compensation expense	4,684		9,666
Loss on assets held for sale	5,026		—
Other non-cash items	(1,303)		(1,204)
Changes in operating assets and liabilities:
Prepaid expenses and other assets	1,520		(14,103)
Operating lease right-of-use assets	4,641		5,621
Accounts payable	3,254		7,072
Accrued expenses and other liabilities	(3,272)		(11,276)
Operating lease liabilities	(3,596)		(3,218)
Deferred revenue	(535)		6,791
Collaboration research advancement	—		(3,744)
Net cash used in operating activities	(41,877)		(49,088)
Cash flows from investing activities:
Purchases of property, plant and equipment	(612)		(6,079)
Proceeds from sale of equipment	176		—
Purchases of marketable securities	(16,565)		(36,093)
Proceeds from maturities of marketable securities	40,000		86,976
Purchases of restricted investments	(6,166)		(2,506)
Proceeds from maturities of restricted investments	5,000		2,500
Net cash provided by investing activities	21,833		44,798
Cash flows from financing activities:
Proceeds from issuance of common stock in public offering, net of issuance costs	—		117,058
Proceeds from issuance of common stock to Regeneron, net of issuance costs	—		9,876
Proceeds from exercise of stock options and ESPP contributions	386		150
Net cash provided by financing activities	386		127,084
(Decrease) increase in cash, cash equivalents and restricted cash and cash equivalents	(19,658)		122,794
Cash, cash equivalents and restricted cash and cash equivalents at beginning of period	76,683		72,290
Cash, cash equivalents and restricted cash and cash equivalents at end of period	$	57,025	$	195,084
Reconciliation of cash, cash equivalents, and restricted cash and cash equivalents
Cash and cash equivalents	$	56,792	$	193,629
Restricted cash and cash equivalents included in restricted investments and other non-current assets	233		1,455
Total cash, cash equivalents, and restricted cash and cash equivalents	$	57,025	$	195,084
Supplemental cash flow disclosures:
Purchases of property, plant and equipment included in accounts payable and accrued expenses	$	95	$	2,342
Financing issuance costs included in accounts payable or accrued expenses	$	—	$	106

See accompanying notes to unaudited condensed consolidated financial statements.

2seventy bio, Inc.

Notes to Condensed Consolidated Financial Statements

(unaudited)

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 and gene therapy company focused on the research, development, and commercialization of transformative treatments for cancer. The Company’s approach combines its expertise in T cell engineering technology and lentiviral vector gene delivery approaches, experience in research, development, and manufacturing of cell therapies and a suite of technologies that can be selectively deployed to develop highly innovative, targeted cellular therapies for patients with 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, 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 “Transaction”). Upon closing of the Transaction, which took place on April 1, 2024, Regeneron assumed all of the ongoing program, infrastructure and personnel costs related to these programs.

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 after the date that the condensed consolidated financial statements are issued. The Company has incurred losses and has experienced negative operating cash flows for all historical periods presented. During the three months ended March 31, 2024, the Company incurred a net loss of $52.7 million and used $41.9 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 March 31, 2024, the Company had cash, cash equivalents, and marketable securities of $181.4 million. Based on the Company’s current operating plans, 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 issuance of these financial statements. 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 pursuing a combination of public or private equity offerings, debt financings, collaborations, strategic alliances or licensing arrangements with third parties. This includes 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 Quarterly Report on Form 10-Q 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

Significant accounting policies

The significant accounting policies used in preparation of these condensed consolidated financial statements are consistent with those discussed in Note 2 to the consolidated financial statements for the year ended December 31, 2023 included in the Company’s 2023 annual report on Form 10-K, except as disclosed below:

Contingent consideration receivable

Under ASC 810, Consolidations, the Company has elected to use the loss recovery approach to account for contingent consideration receivables. 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.

Basis of presentation

The accompanying condensed 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.

In the opinion of management, the unaudited interim condensed consolidated financial statements reflect all normal recurring adjustments considered necessary for a fair presentation of the Company’s financial position and the results of its operations for the interim periods presented.

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, 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, estimates and judgments are 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.

3. Assets held for sale

In January 2024, the Company and Regeneron entered into an asset purchase agreement for the Transaction. The assets consist of property, plant and equipment and prepaid expenses. As consideration for the Asset Sale, Regeneron agreed to pay the Company an upfront payment of $5.0 million and contingent consideration based on regulatory approval and sales-based royalties. 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 $17.8 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 condensed consolidated balance sheets as of March 31, 2024.

As noted above, the Company will receive an upfront payment of $5.0 million upon closing of the Asset Sale, which occurred on April 1, 2024, at the close of the transaction. Moreover, the termination of the Company’s existing Collaboration Agreement with Regeneron (as described in Note 11) was negotiated concurrently with the asset purchase agreement and as such, the Company will derecognize $7.8 million of deferred revenue associated with the Regeneron Collaboration Agreement as part of the Asset Sale. The cash to be 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 to be sold to Regeneron under the asset purchase agreement. As such, the Company recorded an impairment loss of $5.0 million which 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. This is presented as loss on assets held for sale on the condensed consolidated statements of operations and comprehensive loss.

4. Marketable securities

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


	Amortized cost/ cost		Unrealized gains		Unrealized losses		Fair Value
March 31, 2024
U.S. government agency securities and treasuries	$	83,312	$	14	$	(63)	$	83,263
Commercial paper	41,334		6		(13)		41,327
Total	$	124,646	$	20	$	(76)	$	124,590
December 31, 2023
U.S. government agency securities and treasuries	$	101,566	$	144	$	(85)	$	101,625
Commercial paper	45,188		34		—		45,222
Total	$	146,754	$	178	$	(85)	$	146,847

No available-for-sale debt securities held as of March 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 twelve months and twelve months or greater, and for which an allowance for credit losses has not been recorded at March 31, 2024 and December 31, 2023 (in thousands):


	Less than 12 months				12 months or greater				Total
	Fair value		Unrealized losses		Fair value		Unrealized losses		Fair value		Unrealized losses
March 31, 2024
U.S. government agency securities and treasuries	$	22,160	$	(15)	$	26,687	$	(48)	$	48,847	$	(63)
Commercial paper	16,626		(13)		—		—		16,626		(13)
Total	$	38,786	$	(28)	$	26,687	$	(48)	$	65,473	$	(76)
December 31, 2023
U.S. government agency securities and treasuries	$	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, to the consolidated financial statements included in the Company's 2023 annual report on Form 10-K, 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 condensed consolidated balance sheets.

The following table summarizes restricted investments held at March 31, 2024 and December 31, 2023 (in thousands):


	Amortized cost/ cost		Unrealized gains		Unrealized losses		Fair Value
March 31, 2024
U.S. government agency securities and treasuries	$	34,214	$	19	$	(299)	$	33,934
Total	$	34,214	$	19	$	(299)	$	33,934
December 31, 2023
U.S. government agency securities and treasuries	$	33,072	$	67	$	(365)	$	32,774
Total	$	33,072	$	67	$	(365)	$	32,774

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


	Less than 12 months				12 months or greater				Total
	Fair value		Unrealized losses		Fair value		Unrealized losses		Fair value		Unrealized losses
March 31, 2024
U.S. government agency securities and treasuries	$	13,602	$	(43)	$	10,318	$	(256)	$	23,920	$	(299)
Total	$	13,602	$	(43)	$	10,318	$	(256)	$	23,920	$	(299)
December 31, 2023
U.S. government agency securities and treasuries	$	3,496	$	(4)	$	13,266	$	(361)	$	16,762	$	(365)
Total	$	3,496	$	(4)	$	13,266	$	(361)	$	16,762	$	(365)

Accrued interest receivables on the Company's available-for-sale debt securities and restricted investments, included within receivables and other current assets in the Company’s condensed consolidated balance sheet, totaled $0.8 million as of March 31, 2024 and December 31, 2023. No accrued interest receivable was written off during the three months ended March 31, 2024 or 2023.

The amortized cost of available-for-sale debt securities and restricted investments is adjusted for amortization of premiums and accretion of discounts to the earliest call date for premiums or to maturity for discounts. At March 31, 2024 and December 31, 2023, the balance in the Company’s accumulated other comprehensive loss was composed primarily of activity related to the Company’s available-for-sale debt securities and restricted investments. There were no material realized gains or losses recognized on the sale or maturity of available-for-sale securities or restricted investments during the three months ended March 31, 2024 and 2023.

The Company determined that there was no material change in the credit risk of the above investments during the three months ended March 31, 2024. As such, an allowance for credit losses was not recognized. As of March 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 March 31, 2024 and December 31, 2023 (in thousands):


	Total		Quoted prices in active markets (Level 1)		Significant other observable inputs (Level 2)		Significant unobservable inputs (Level 3)
March 31, 2024
Assets:
Cash and cash equivalents	$	56,792	$	56,792	$	—	$	—
Marketable securities:
U.S. government agency securities and treasuries	83,263		—		83,263		—
Commercial paper	41,327		—		41,327		—
Restricted cash and cash equivalents	233		233		—		—
Restricted investments	33,934		—		33,934		—
Total assets	$	215,549	$	57,025	$	158,524	$	—
Liabilities:
Contingent consideration	$	685	$	—	$	—	$	685
Total liabilities	$	685	$	—	$	—	$	685
December 31, 2023
Assets:
Cash and cash equivalents	$	74,958	$	74,958	$	—	$	—
Marketable securities:
U.S. government agency securities and treasuries	101,625		—		101,625		—
Commercial paper	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

Contingent consideration

In connection with bluebird bio's prior acquisition of Precision Genome Engineering, Inc. (“Pregenen”) in 2014, the Company may be required to pay future consideration that is contingent upon the achievement of certain commercial 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 condensed 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. Contingent consideration is included in other non-current liabilities on the condensed consolidated balance sheets.

The table below provides a roll-forward of fair value of the Company’s contingent consideration obligations that include Level 3 inputs (in thousands):


	For the three months ended March 31, 2024
Beginning balance	$	2,415
Additions	—
Changes in fair value	(1,730)
Payments	—
Ending balance	$	685

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):


	As of March 31, 2024		As of December 31, 2023
Computer equipment and software	$	5,844	$	6,156
Office equipment	6,330		6,726
Laboratory equipment	4,328		43,209
Leasehold improvements	48,340		58,832
Construction-in-progress	16		138
Total property, plant and equipment	64,858		115,061
Less accumulated depreciation and amortization	(26,624)		(56,911)
Property, plant and equipment, net	$	38,234	$	58,150

For further detail regarding the classification of property, plant, and equipment included in the Asset Sale to Regeneron, please refer to Note 3, Assets held for sale.

7. Accrued expenses and other current liabilities

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


	As of March 31, 2024		As of December 31, 2023
Collaboration research costs	$	9,041	$	5,681
Employee compensation, including severances for restructuring	5,097		4,639
Royalties	2,684		9,702
Clinical and contract research organization costs	985		990
Manufacturing costs	497		1,764
Property, plant, and equipment	—		279
Other	3,959		2,633
Total accrued expenses and other current liabilities	$	22,263	$	25,688

8. Leases

The Company leases certain office and laboratory space, primarily located in Cambridge, Massachusetts and Seattle, Washington, that was assigned to it in connection with the separation. In connection with the Transaction, Regeneron agreed to sublease the Company’s facilities in Seattle, Washington and a portion of the Company’s facilities in Cambridge, Massachusetts. The expected sublease income will cover a majority of the future minimum commitments through 2027. The Company will remain the primary obligor of the leases. There have been no material changes to the lease obligations from those disclosed in Note 7, Leases, to the consolidated financial statements included in the Company's 2023 annual report on Form 10-K.

9. Commitments and contingencies

Contingent consideration related to business combinations

On June 30, 2014, bluebird bio acquired Pregenen. All assets, liabilities and future obligations related to the Pregenen acquisition, including the resulting goodwill and contingent consideration, were assumed by the Company in connection with the separation from bluebird bio. As of March 31, 2024, the Company may be required to make up to $99.9 million in 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 condensed 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. Please refer to Note 5, Fair value measurements, for further information.

Other funding commitments

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 assigned to the Company, bluebird bio entered into a sublicense with the Company, which may require the Company to make 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 Nordisk A/S (“Novo”) agreements and to Note 12, Royalty and other revenue, for further information on license agreements.

Based on the Company's development plans as of March 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.

Additionally, 2seventy bio is 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. There have been no material changes in future minimum purchase commitments from those disclosed in Note 8, Commitments and Contingencies, to the consolidated financial statements included in the Company's 2023 annual report on Form 10-K.

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. Equity

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.

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. These agreements were assumed by the Company in connection with the separation from bluebird bio as described in Note 14.

Bristol-Myers Squibb

BMS Collaboration Agreement

In March 2013, bluebird bio entered into a collaboration agreement with BMS. The details of the collaboration agreements and the payments the Company has received, and is entitled to receive, are further described in Note 10, Collaborative arrangements and strategic partnerships, to the consolidated financial statements included in the Company's 2023 annual report on Form 10-K. During the second quarter of 2023, the Company entered into an amendment to the collaboration agreement with BMS to assign future manufacturing of lentiviral vector to BMS, as further described in Note 8, Commitments and contingencies, to the consolidated financial statements included in the Company's 2023 annual report on Form 10-K.

Abecma

Under the collaboration agreement with BMS, 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). If the Company were to choose to terminate its existing agreement with BMS, it would be entitled to a mid-single digit to low teens royalty based on a percentage of net sales of Abecma in the United States with 90 days’ notice. 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 First Amendment to the Amended and Restated Co-Development, Co-Promote and Profit Share Agreement (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 condensed consolidated statement 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 and both companies continue to develop suspension lentiviral vector to be used in the manufacture of Abecma. 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 three months ended March 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.


	For the three months ended March 31,
Abecma U.S. Collaboration Profit/Loss Share	2024		2023
2seventy's share of profits (losses), net of 2seventy's share of BMS costs for commercial activities	$	(1,975)	$	21,581
Reimbursement from BMS for 2seventy costs of commercial manufacturing and commercial activities	745		1,380
Collaborative arrangement revenue (1)	$	—	$	22,961
Share of collaboration loss (1)	$	(1,230)	$	—

(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.

The following tables summarize the amounts associated with the research activities under the collaboration included in research and development expense or recognized as collaborative arrangement revenue for the three months ended March 31, 2024 and 2023 (in thousands):


	For the three months ended March 31,
Abecma U.S. Collaboration Net R&D Expenses	2024		2023
2seventy's obligation for its share of BMS research and development expenses	$	(6,963)	$	(9,461)
Reimbursement from BMS for 2seventy research and development expenses	224		4,590
Net R&D expense (1)	$	(6,739)	$	(4,871)

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

March 31, 2024 and 2023 (in thousands). These amounts are reflected in service revenue in the consolidated statements of operations and comprehensive loss:


	For the three months ended March 31,
	2024		2023
ASC 606 ide-cel license and manufacturing revenue – ex-U.S. (included as a component of service revenue) (1)	$	2,201	$	6,123

(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.

Regeneron

Please refer to Note 18, Subsequent Events, for further information on the terms of the Transaction to Regeneron. Upon closing of the Transaction on April 1, 2024, the Collaboration Agreement with Regeneron described below was terminated. Please refer to Note 3, Assets held for sale for further information regarding the accounting treatment for the termination.

Regeneron Collaboration Agreement

In August 2018, bluebird bio entered into a Collaboration Agreement (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. In August 2018, following the completion of required regulatory reviews, the Regeneron Collaboration Agreement became effective. As noted above, the agreement was assumed by the Company in connection with the separation. Under the terms of the agreement, the parties will leverage Regeneron’s proprietary platform technologies for the discovery and characterization of fully human antibodies, as well as T cell receptors directed against tumor-specific proteins and peptides and the Company will contribute its field-leading expertise in gene therapy.

In accordance with the Regeneron Collaboration Agreement, the parties jointly selected six initial targets and intend to equally share the costs of research up to the point of submitting an Investigational New Drug (“IND”) application for a potential gene therapy product directed to a particular target. Additional targets may be selected to add to or replace any of the initial targets during the five-year research collaboration term as agreed to by the parties.

Regeneron will accrue a certain number of option rights exercisable against targets as the parties reach certain milestones under the terms of the agreement. Upon the acceptance of an IND for the first product candidate directed to a target, Regeneron will have the right to exercise an option for co-development/co-commercialization of product candidates directed to such target on a worldwide or applicable opt-in territory basis, with certain exceptions. Where Regeneron chooses to opt-in, the parties will share equally in the costs of development and commercialization and will share equally in any profits or losses therefrom in applicable opt-in territories. Outside of the applicable opt-in territories, the target becomes a licensed target and Regeneron would be eligible to receive, with respect to any resulting product, milestone payments of up to $130.0 million per product and royalties on net sales outside of the applicable opt-in territories at a rate ranging from the mid-single digits to low-double digits. A target would also become a licensed target in the event Regeneron does not have an option to such target, or Regeneron does not exercise its option with respect to such target.

Either party may terminate a given research program directed to a particular target for convenience, and the other party may elect to continue such research program at its expense, receiving applicable cross-licenses. The terminating party will receive licensed product royalties and milestone payments on the potential applicable gene therapy products. Where the Company terminates a given research program for convenience, and Regeneron elects to continue such research program, the parties will enter into a transitional services agreement. Under certain conditions, following its opt-in, Regeneron may terminate a given collaboration program and the Company may

elect to continue the development and commercialization of the applicable potential gene therapy products as licensed products.

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 have identified four research targets to advance the next stage of research therapies. The parties will continue sharing costs for these activities in a manner largely consistent with the existing agreement, with Regeneron now covering 75% of eligible late-stage research costs to study combinations and 100% of the costs for the arms of clinical studies that include Regeneron agents through regulatory approval of two of the four targets. For other programs, cost-sharing will follow the existing 50/50 cost sharing agreement.

Additionally, Regeneron will 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 include:

•$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 has already occurred and will not be due until the Clinical Candidate milestone event (IND Acceptance) is achieved for MUC-16 at which time the first milestone will be reduced to $1.0 million for a total amount due for the two milestones related to MUC-16 of $4.0 million.

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 – 2018 Regeneron Collaboration Agreement

At the commencement of the original Regeneron Collaboration Agreement, two units of accounting were identified, which are the issuance of 0.4 million shares of bluebird bio’s common stock and joint research activities during the five-year research collaboration term. The Company determined the total transaction price to be $100.0 million, which comprises $54.5 million attributed to the bluebird bio equity sold to Regeneron and $45.5 million attributed to the joint research activities. In determining the fair value of the bluebird bio common stock at closing,

the Company considered the closing price of the bluebird 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.

The Company analyzed the joint research activities to assess whether they fall within the scope of ASC 808, and will reassess this throughout the life of the arrangement based on changes in the roles and responsibilities of the parties. Based on the terms of the arrangement as outlined above, for the collaboration research performed prior to submission of an IND application for a potential gene therapy product, both parties are deemed to be active participants in the collaboration. Both parties are performing research and development activities and will share equally in these costs through IND submission. Additionally, Regeneron and the Company are 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 is deemed to be within the scope of ASC 808.

The $45.5 million attributed to the joint research activities includes the $37.0 million creditable against amounts owed to the Company by Regeneron. The collaboration research advancement will be reduced over time for amounts due to the Company by Regeneron as a result of the parties agreeing to share in the costs of collaboration research equally. The remainder of $8.5 million will be attributed to the joint research activities and recognized over the five-year research collaboration term. As of December 31, 2022, $1.1 million of the premium remained to be recognized.

Consistent with its collaboration accounting policy, the Company will recognize collaboration revenue or research and development expense related to the joint research activities in future periods depending on the amounts incurred by each party in a given reporting period. That is, if the Company’s research costs incurred exceed those research costs incurred by Regeneron in a given quarter, the Company will record collaboration revenue and reduce the original $37.0 million advance by the amount due from Regeneron until such advancement is fully utilized, after which the Company would record an amount due from Regeneron. If Regeneron’s research costs incurred exceed those research costs incurred by the Company in a given quarter, the Company will record research and development expense and record a liability for the amount due to Regeneron. As of December 31, 2022, the Company had $3.7 million of collaboration research advancement credit attributed to the joint research activities still to be recognized. The research credit was fully utilized in the first quarter of 2023.

Accounting analysis - Regeneron Amendment

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 will reassess 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 continue to be active participants in the collaboration. Both parties continue to perform research and development activities and will share in these costs through IND submission. Additionally, Regeneron and the Company continue 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 is 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 are 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 is 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 continue to be fully constrained until such time as the achievement of such milestones are considered probable.

The Company concluded that it continues to satisfy its obligations over-time as Regeneron receives the benefit of the research activities as the activities are performed. The Company determined the most appropriate method to track progress towards completion of the four performance obligations is an input method that is based on costs incurred. There are 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 include a number of objective and subjective factors, including the likelihood that a target will 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 will be recognized in the period in which they change as a cumulative catch-up.

As noted, the four targets represent four distinct performance obligations and as such, the Company has allocated the total transaction price of $11.2 million among the four performance obligations based on the stand-alone selling price of each target.

The following table summarizes the allocation of the transaction price to each performance obligation and the amount of the allocated transaction price that is unsatisfied or partially unsatisfied as of March 31, 2024, which the Company expects to recognize as revenue as the targets progress through each of the target’s respective IND filing (in thousands):


Performance Obligation	Allocation of Transaction Price		Unsatisfied Portion of Transaction Price
MUC16 Mono/Combo & Next Gen Therapies	$	1,905	$	—
MAGE-A4	178		—
Early Research Target (1)	8,701		7,394
Early Research Target (2)	475		392
Total	$	11,259	$	7,786

As of March 31, 2024, approximately $7.8 million remains in collaboration deferred revenue, of which $5.3 million is included in deferred revenue, current portion and $2.5 million is included in deferred revenue, net of current portion on the condensed consolidated balance sheets. As part of the Asset Sale, the total deferred revenue of $7.8 million will be derecognized. Refer to Note 3, Assets held for sale, for further detail.

During the first quarter of 2024, the Company received a milestone payment of $4.0 million from Regeneron relating to IND acceptance for the MUC16 target. As the filing of IND for the target is complete, the performance obligation relating to the target is satisfied and the Company recognized the full $4.0 million as service revenue on the condensed consolidated statement of operations for the three months ended March 31, 2024 under ASC 606.

The Company recognized $4.7 million and $6.4 million of collaborative arrangement revenue from the Regeneron Collaboration Agreement for the three months ended March 31, 2024 and 2023, respectively. As of March 31, 2024, amounts due from Regeneron total $4.2 million, included within receivables and other current assets on the condensed consolidated balance sheets.

JW Therapeutics

Please refer to Note 18, Subsequent Events, for further information on the terms of the Transaction with Regeneron. Upon closing of the Transaction on April 1, 2024, this program was assumed by Regeneron, including all upfront milestone and royalty payments to be made by 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 will grant JW a license for the MAGE-A4 cell therapy in the Chinese mainland, Hong Kong (China), and Macao (China). JW will be responsible for development, manufacturing, and commercialization of the Initial Product within China. The Company is eligible to receive milestones and royalties on product revenues in China. The Company and Regeneron will 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 is 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 has concluded the manufacturing and supply of vector is a distinct performance obligation from the license for MAGE-A4 cell therapy because there are 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. As of March 31, 2024, the unsatisfied portion of the variable consideration for the reimbursement of vector supply is $3.7 million.

Novo Nordisk

Novo Collaboration and License Agreement

In December 2021, the Company entered into a Collaboration and License Agreement (the “Novo Collaboration Agreement”) with Novo for the discovery, development, and commercialization of a potential new gene therapy in hemophilia A. The Company and Novo have agreed to develop an initial research program with the goal of researching and developing a lead candidate directed to hemophilia A. The Company will provide Novo with research licenses to support the companies’ activities during the initial research program and an option to enable Novo to obtain an exclusive license to commercialize the product derived from or containing compounds developed during the initial research program.

Under the terms of the Novo Collaboration Agreement, Novo agreed to pay the Company:

•a non-refundable, non-creditable upfront payment of $5.0 million;

•$15.0 million upon achievement of certain scientific milestones during the initial research program, or $9.0 million should Novo decide to continue the initial research program without achieving the scientific milestones;

•up to $26.0 million of exclusive license fees for the development, manufacture, and commercialization of the product should Novo exercise its option; and,

•up to $72.0 million in development and commercialization milestones.

Novo also agreed to reimburse the Company for research costs incurred in connection with the research program up to a mutually agreed upon amount. If Novo exercises its option to obtain a license to commercialize the product developed during the initial research program, the Company is also eligible to receive a mid-single digit percentage of royalties on product sales on a country-by-country and product-by-product basis, subject to certain royalty step-down provisions set forth in the agreement.

Accounting Analysis - Novo

The Company concluded that Novo is a customer, and as such, the arrangement falls within the scope of Topic 606. The Company identified two performance obligations consisting of (i) the research license and research and development services to be provided during the initial research program and (ii) a material right related to Novo’s option to obtain an exclusive license for the development, manufacture, and commercialization of the product developed during the initial research program. The Company determined that the research license and research and development services promises were not separately identifiable and were not distinct or distinct within the context of the contract due to the specialized nature of the services to be provided by 2seventy, specifically with respect to the Company’s expertise related to gene therapy and the interdependent relationship between the promises. The material right is considered a separate performance obligation pursuant to the provisions of Topic 606.

At contract inception, the Company determined the unconstrained transaction price was $11.7 million, consisting of the $5.0 million in up-front consideration and the $6.7 million in reimbursement for the research and development services. Variable consideration associated with the scientific milestones was fully constrained due to the uncertainty associated with the outcome of the research efforts under the initial research program. The Company allocated $6.7 million of the transaction price to the research services and $5.0 million to the material right using a relative selling price methodology. Management will re-evaluate the transaction price at the end of each reporting period and as uncertain events are resolved or other changes in circumstances occur and adjust the transaction price as necessary.

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 may elect to exercise an option to in-license technology from a third party in connection with the Novo Collaboration Agreement, for which the Company is 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 aforementioned $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, is allocated to the material right alongside the $5.0 million upfront payment. The total $11.0 million is included in deferred revenue, net of current portion, as of March 31, 2024, and will be recognized when Novo exercises its option to obtain a license to commercialize the product developed.

Revenue associated with the research and development performance obligation will be recognized as services are provided and costs are incurred. For the three months ended March 31, 2024, and 2023, the Company recognized $1.5 million and $1.7 million of service revenue under this agreement, respectively.

12. Royalty and other revenue

bluebird bio has out-licensed intellectual property to various third parties. Under the terms of these agreements, some of which were assumed by the Company in connection with the separation, bluebird bio and the Company may be entitled to royalties and milestone payments.

Juno Therapeutics

In May 2020, bluebird bio entered into a non-exclusive license agreement with Juno Therapeutics, Inc. (“Juno”), 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 condensed 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 $0.0 million and $1.4 million of royalty and other revenue for the three months ended March 31, 2024, and 2023, respectively.

13. Stock-based compensation

In connection with 2seventy bio’s separation from bluebird bio in 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 Note 13, Stock-based compensation, to the consolidated financial statements included in our annual report on Form 10-K for the year ended December 31, 2023 for details on the conversion methodology of the equity awards.

In October 2021, the Company’s board of directors adopted the 2021 Stock Option and Incentive Plan (“2021 Plan”) which allows for the granting of incentive stock options, non-qualified stock options, restricted stock units, performance-based restricted stock units, and restricted stock awards to 2seventy bio’s employees, members of the board of directors, and consultants of 2seventy bio, including those who became employees of the Company in connection with the separation. Shares of the Company’s common stock underlie all awards granted under the 2021 Plan.

Stock-based compensation expense

Stock-based compensation expense includes compensation cost related to 2seventy bio equity awards held by its employees as well as bluebird bio equity awards issued upon separation to its employees.

Stock-based compensation expense recognized by award type was as follows (in thousands):


	For the three months ended March 31,
	2024		2023
Stock options	$	1,843	$	3,865
Restricted stock units	2,778		5,727
Employee Stock Purchase Plan	63		74
	$	4,684	$	9,666

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


	For the three months ended March 31,
	2024		2023
Research and development	$	1,645	$	3,618
Selling, general and administrative	2,528		6,048
Restructuring expenses	511		—
	$	4,684	$	9,666

Employee Stock Purchase Plan

During the three months ended March 31, 2024, 0.1 million shares of common stock were issued under the Company’s 2021 Employee Stock Purchase Plan (“ESPP”).

14. Related-party transactions

Relationship with bluebird bio

In January 2021, bluebird bio, Inc. (“bluebird bio”) announced its plans to separate oncology portfolio and programs from its severe genetic disease portfolio and programs, and spin off its oncology portfolio and programs into a separate, publicly traded company (the “Separation”). In connection with the Separation, the Company entered into certain agreements pursuant to which the separation of its business from bluebird bio was effected and that govern its relationship with bluebird bio going forward. The separation agreement, tax matters agreement, employee matters agreement, intellectual property license agreement (“License Agreement”) and two transition services agreements are described in Note 14, Related-party transactions, to the consolidated financial statements included in the Company’s 2023 annual report on Form 10-K. The transition services agreements have since been terminated. Prior to the separation, all of Company’s outstanding shares of common stock were owned by bluebird bio and therefore the transactions under those agreements were considered and disclosed as related party transactions. Following the completion of the separation and distribution, the Company and bluebird bio have operated separately, each as an independent public company and bluebird bio no longer owns any shares of the Company’s common stock. Therefore, transactions under those agreements are no longer accounted for as related party transactions.

15. Income taxes

Deferred taxes are recognized for temporary differences between the basis of assets and liabilities for financial statement and income tax purposes. 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.

16. 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):


	For the three months ended March 31,
	2024	2023
Outstanding stock options (1)	3,974	3,571
Restricted stock units (1)	1,932	2,678
ESPP shares	—	—
	5,906	6,249

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

As described further in Note 9, Stockholders’ equity, to the consolidated financial statements included in the Company’s 2023 annual report on Form 10-K, in November 2021, the Company issued to certain institutional investors (who previously purchased pre-funded warrants to purchase shares of bluebird bio common stock) pre-funded warrants to purchase 757,575 shares of the Company’s common stock at an exercise price of $0.0001 per share. The pre-funded warrants can be exercised at any time or times on or after November 4, 2021, until exercised in full. Based on the terms of the pre-funded warrants, management concluded that they should be considered outstanding shares in the computation of basic and diluted net loss per share.

17. Corporate Restructuring

September 2023 Restructuring Plan

In August 2023, the Company’s board of directors approved a restructuring plan (the “2023 Restructuring Plan”) to conserve financial resources and better align the Company’s workforce with current business needs. As part of the 2023 Restructuring Plan, the Company's workforce was reduced by approximately 40% in September 2023. The Company’s 2023 Restructuring Plan is substantially complete as of March 31, 2024.

In connection with the 2023 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 were included in restructuring expenses on the condensed consolidated statements of operations and comprehensive loss. Since inception of the 2023 Restructuring Plan, the Company has paid a total of $8.4 million of the accrued restructuring costs. The remaining accrued liability for the plan is approximately $0.2 million as of March 31, 2024 and is included in accrued expenses and other current liabilities on the condensed consolidated balance sheets.

January 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 Restructuring Plan transitioned to Regeneron as a part of the 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 by October 2024.

In connection with the 2024 Restructuring Plan, the Company expects to incur approximately $6.9 million of costs for severance and related benefits and stock-based compensation expense. These costs will be recognized over the period from January 2024 through October 2024, and are disclosed as restructuring expenses on the condensed 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 March 31, 2024:


	Expense recognized for the three months ended March 31, 2024		Total expense expected to be recognized
Cash-related restructuring expenses:
Severance and related benefits	$	3,720	$	5,815
Non-cash expenses:
Stock-based compensation expense	510		1,037
Total restructuring expenses	$	4,230	$	6,852

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


	For the three months ended March 31, 2024
Beginning balance at January 1, 2024	$	—
Cash-related expenses recognized	3,720
Cash-related expenses paid	(667)
Reversal of excess accrual	—
Remaining accrual at March 31, 2024 (1)	$	3,053

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

18. Subsequent Events

On April 1, 2024, the Company completed the Transaction, pursuant to which the Company agreed to sell to Regeneron the Company’s oncology and autoimmune research and development programs, clinical manufacturing capabilities, and related platform technologies.

Pursuant to the Asset Purchase Agreement dated January 29, 2024 (the “Asset Purchase Agreement”), in consideration for the Transferred Assets, at the closing of the Transaction, Regeneron made an upfront payment to the Company of $5.0 million in cash and also assumed certain liabilities of the Company arising after the Closing Date, including liabilities (i) related to the conduct of the R&D Pipeline Programs, (ii) under transferred contracts and (iii) with respect to certain of the Company’s employees (collectively, the “Assumed Liabilities”). In addition to the upfront consideration, Regeneron has agreed to pay the Company (i) a one-time $10.0 million milestone payment (“Milestone Payment”) upon the earlier of (a) the first receipt of regulatory approval and (b) the first commercial sale for the first product candidate within the Transferred Assets in certain specified countries and (ii) agreed-upon royalty payments (“Net Sales Payments”) based on net sales of the product candidates if commercialized.

In connection with the Asset Purchase Agreement, Regeneron also agreed to sublease the Company’s facilities in Seattle, Washington, and a portion of the Company’s facilities in Cambridge, Massachusetts (collectively, the “Premises”). The Company also entered into a facilities service agreement to provide certain facilities and administrative services to Regeneron as it relates to the Premises. In addition, the Company and Regeneron entered into a transition services agreement at the closing of the Transaction under which the Company agreed to provide agreed upon services to Regeneron for a period up to one year following the close of the Transaction, subject to early termination. Lastly, effective as of the Closing Date, the Regeneron Collaboration Agreement was terminated.

ITEM 2. MANAGEMENT'S DISCUSSION AND ANALYSIS OF FINANCIAL CONDITION AND RESULTS OF OPERATIONS

The following information should be read in conjunction with the unaudited financial information and the notes thereto included in this Quarterly Report on Form 10-Q and the audited financial information and the notes thereto included in the Company’s 2023 annual report on Form 10-K, which was most recently filed with the Securities and Exchange Commission, or the SEC, on March 7, 2024.

Except for the historical information contained herein, the matters discussed in this Quarterly Report on Form 10-Q may be deemed to be 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. In this Quarterly Report on Form 10-Q, words such as “may,” “expect,” “anticipate,” “estimate,” “intend,” “plan,” and similar expressions (as well as other words or expressions referencing future events, conditions or circumstances) are intended to identify forward-looking statements.

Our actual results and the timing of certain events may differ materially from the results discussed, projected, anticipated, or indicated in any forward-looking statements. We caution you that forward-looking statements are not guarantees of future performance and that our actual results of operations, financial condition and liquidity, and the development of the industry in which we operate may differ materially from the forward-looking statements contained in this Quarterly Report. In addition, even if our results of operations, financial condition and liquidity, and the development of the industry in which we operate are consistent with the forward-looking statements contained in this Quarterly Report, they may not be predictive of results or developments in future periods.

We caution readers not to place undue reliance on any forward-looking statements made by us, which speak only as of the date they are made. We disclaim any obligation, except as specifically required by law and the rules of the SEC, to publicly update or revise any such statements to reflect any change in our expectations or in events, conditions or circumstances on which any such statements may be based, or that may affect the likelihood that actual results will differ from those set forth in the forward-looking statements.

Overview

We are a cell and gene 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, from discovery through clinical development to regulatory approval of idecabtagene vicleucel (ide-cel, marketed in the United States as Abecma). Our approach combines our expertise in T cell engineering technology and lentiviral vector gene delivery approaches, experience in research, development, and manufacturing of cell therapies and a suite of technologies that can be selectively deployed to develop highly innovative, targeted cellular therapies for patients with cancer. 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 5, 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.

On January 29, 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 an asset purchase agreement with Regeneron to sell to Regeneron substantially all of the assets 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 (the “Asset Sale”). Upon closing the transaction on April 1, 2024, Regeneron assumes all of the ongoing program infrastructure and personnel costs related to these programs. We have incurred losses and have experienced negative operating cash flows for all historical periods presented. During the three months ended March 31, 2024, we incurred a net loss of $52.7 million

and used $41.9 million of cash in operations. We expect to continue to generate operating losses and negative operating cash flows for the near future.

As we continue to develop and seek to obtain regulatory approval for Abecma in earlier lines of therapy, expand site footprint, educate physicians on treatment sequencing and the emerging data supporting the use of BCMA-directed CAR Ts before other BCMA-targeted therapies, competitively differentiate Abecma’s real-world safety, efficacy and product reliability and predictability profile, continue to support the quality control of the LVV, manufacturing and the transition to suspension LVV, we expect to incur significant expenses. 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. 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.

Financial Operations Overview

Revenue

Our revenues have been derived from collaboration arrangements and out-licensing arrangements, primarily related to our collaboration arrangement with BMS as part of which we are jointly commercializing Abecma in the United States. 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.

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.


Nature of Payment						Statement of Operations Presentation
Our share of net profits in connection with commercialization of products						Collaborative arrangement revenue
Our share of net losses in connection with commercialization of products						Share of collaboration loss
Net reimbursement to us for research and development expenses						Collaborative arrangement revenue
Net reimbursement to the collaborator for research and development expenses						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 by the Company, in the period in which such underlying sales occur and costs are incurred by the collaborator. We also recognize our share of costs arising from research and development activities performed by collaborators in the period our collaborators incur such expenses.

As we recognize revenue under our collaborative arrangements both within and outside the scope of Topic 606, we present revenue on our consolidated statements of operations and comprehensive loss as follows: service revenue includes revenue from collaborative partners recognized within the scope of Topic 606 and collaborative arrangement revenue includes only revenue from collaborative partners recognized outside the scope of Topic 606.

For the three months ended March 31, 2024 and 2023, service revenue consisted of the following (in thousands):


	For the three months ended March 31,
	2024		2023
ide-cel ex-U.S. service revenue from BMS	$	2,201	$	6,123
Service revenue from December 2021 agreement with Novo Nordisk	1,520		1,703
Other	4,000		3,000
Total service revenue	$	7,721	$	10,826

For the three months ended March 31, 2024 and 2023, collaborative arrangement revenue consisted of the following (in thousands):


	For the three months ended March 31,
	2024		2023
U.S. Abecma collaboration with BMS	$	—	$	22,961
Collaboration with Regeneron	4,714		6,411
Total collaborative arrangement revenue	$	4,714	$	29,372

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 condensed 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 condensed consolidated statements of operations and comprehensive loss for the three months ended March 31, 2024 and 2023 (in thousands).


	For the three months ended March 31,
Abecma U.S. Collaboration Profit (Loss) Share	2024		2023
Our share of profits (losses), net of our share of BMS costs for commercial activities	$	(1,975)	$	21,581
Reimbursement from BMS for our costs of commercial manufacturing and commercial activities	745		1,380
Collaborative arrangement revenue (1)	$	—	$	22,961
Share of collaboration loss (1)	$	(1,230)	$	—

Costs of commercial manufacturing incurred by us, prior to BMS reimbursement	(1,428)		(2,583)
Costs of commercial activities incurred by us, prior to BMS reimbursement	(63)		(176)
Total impact of Abecma U.S. collaboration profit (loss) on our statements of operations and comprehensive loss	$	(2,721)	$	20,202

(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.

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

Research and development expenses consist primarily of costs incurred for the development of our product candidates, which include:

•employee-related expenses, including salaries, benefits, travel and stock-based compensation expense;

•expenses incurred under agreements with CROs and clinical sites that conduct our clinical studies;

•costs related to acquiring and manufacturing clinical study materials;

•reimbursable costs to our partners for collaborative activities;

•facilities, depreciation, and other expenses, which include direct and allocated expenses for rent and maintenance of facilities, information technology, insurance, and other supplies in support of research and development activities;

•costs associated with our research platform and preclinical activities;

•milestones and upfront license payments;

•costs associated with our regulatory, quality assurance and quality control operations; and

•amortization of certain intangible assets.

Our research and development expenses include expenses associated with the following activities:

•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.

•CRC-403 study – an open-label, multi-site Phase 1/2 dose-escalation study to examine the safety and efficacy of bbT369 in relapsed and/or refractory B Cell Non-Hodgkin's Lymphoma (NHL).

•PLAT-08 study – an open-label Phase 1 study to examine the safety and efficacy of SC-DARIC33 in pediatric and young adult relapsed or refractory acute myeloid leukemia (AML).

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 to us by our vendors and our clinical sites. We cannot determine with certainty the duration and completion costs of the current or future clinical studies of Abecma or if, when, or to what extent we will generate revenues from the commercialization and sale of any of our product candidates that obtain regulatory approval. We may not succeed in achieving regulatory approval for all of our product candidates. The duration, costs, and timing of clinical studies and development of our product candidates will depend on a variety of factors, any of which could mean a significant change in the costs and timing associated with the development of our product candidates including:

•the scope, rate of progress, and expense of our ongoing as well as any additional clinical studies and other research and development activities we undertake;

•future clinical study results;

•uncertainties in clinical study enrollment rates;

•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.

We expect our ongoing research and development expenses to be driven mainly by funding our share of the costs of development of Abecma, including clinical expansion to earlier lines of therapy, through our collaboration with BMS.

Our direct research and development expenses consist principally of internal and external costs, such as fees paid to investigators, consultants, central laboratories and CROs in connection with our clinical studies, and costs related to acquiring and manufacturing clinical study materials. We allocate salary and benefits, personnel-related discretionary bonus, and stock-based compensation costs directly related to specific programs. We do not allocate certain general research and platform personnel costs, certain laboratory and related expenses, rent expense,

depreciation or other indirect costs that are deployed across multiple projects under development and, as such, the costs are separately classified as other research and development expenses in the table below:


	For the three months ended March 31,
	2024		2023
ide-cel(1)	$	7,304	$	17,594
bb21217	38		888
bbT369	4,509		9,971
SC-DARIC33(2)	—		1,294
Preclinical programs	9,173		14,562
Total direct research and development expenses	21,024		44,309
General research and platform personnel costs	4,693		5,506
Unallocated laboratory and manufacturing expenses	3,167		2,490
Facility and other support costs	15,047		15,941
Total other research and development expenses	22,907		23,937
Total research and development expenses	$	43,931	$	68,246

(1) ide-cel research and development expenses included above are substantially global in nature and benefit both U.S. and ex-U.S. territories.

(2) In August 2023, the FDA placed the study on clinical hold due to a fatal (Grade 5) serious adverse event, or SAE, in a patient enrolled in the Phase 1 trial of the PLAT-08 study. The clinical hold was lifted by the FDA in December 2023.

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 condensed 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 condensed 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 condensed consolidated statements of operations and comprehensive loss.

Restructuring expenses

Costs relating to both the September 2023 and January 2024 restructurings have been recorded as restructuring expenses in our condensed consolidated statements of operations and comprehensive loss.

In September 2023, we announced a restructuring plan (“2023 Restructuring Plan”) to conserve financial resources and better align our workforce with current business needs. As part of the 2023 Restructuring Plan, our workforce was reduced by approximately 40%, with substantially all of the reduction in personnel to be completed by December 31, 2023. In connection with the 2023 Restructuring Plan, we incurred one-time costs in the third quarter of 2023 relating to severance and retention packages and related benefits.

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 a restructuring plan (the “2024 Restructuring Plan”) to further reduce its remaining workforce by approximately 14%. The 2024 Restructuring Plan is expected to be substantially complete by October 2024.

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 March 31, 2024, there were $99.9 million in future contingent cash payments related to commercial milestones. We estimate future contingent cash payments have a fair value of $0.7 million as of March 31, 2024, which are classified within other non-current liabilities on our condensed consolidated balance sheet.

Loss on assets held for sale

The loss on assets held for sale consists of fixed assets that ceased depreciation and measured at the lower of its 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.

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 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. 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. During the three months ended March 31, 2024, there were no material changes to our significant accounting policies as reported in our annual consolidated financial statements included in our 2023 annual report on Form 10-K, except as otherwise described in Note 2, Basis of presentation, principles of consolidation and significant accounting policies, in the notes to the condensed consolidated financial statements.

Results of Operations

The following discussion summarizes the key factors we believe are necessary for an understanding of our condensed consolidated financial statements.

Comparison of the Three Months Ended March 31, 2024 and 2023:


	For the three months ended March 31,
	2024		2023		Change
	(in thousands)
Revenue:
Service revenue	$	7,721	$	10,826	$	(3,105)
Collaborative arrangement revenue	4,714		29,372		(24,658)
Royalty and other revenue	—		1,423		(1,423)
Total revenues	12,435		41,621		(29,186)
Operating expenses:
Research and development	43,931		68,246		(24,315)
Cost of manufacturing for commercial collaboration	3,269		3,654		(385)
Selling, general and administrative	12,659		20,720		(8,061)
Share of collaboration loss	1,230		—		1,230
Restructuring expenses	4,230		—		4,230
Cost of royalty and other revenue	—		641		(641)
Change in fair value of contingent consideration	(1,730)		73		(1,803)
Total operating expenses	63,589		93,334		(29,745)
Loss from operations	(51,154)		(51,713)		559
Interest income, net	2,861		2,049		812
Other income, net	646		2,643		(1,997)
Loss on assets held for sale	(5,026)		—		(5,026)
Loss before income taxes	(52,673)		(47,021)		(5,652)
Income tax (expense) benefit	—		—		—
Net loss	$	(52,673)	$	(47,021)	$	(5,652)

Revenue. Total revenue was $12.4 million for the three months ended March 31, 2024, compared to $41.6 million for the three months ended March 31, 2023. The decrease of $29.2 million was primarily attributable to a decrease in collaborative arrangement revenue recognized under our collaboration arrangement with BMS, driven by decreased Abecma net sales and higher BMS selling, general and administrative expenses. This resulted in a share of collaboration loss position in the first quarter of 2024 . The decrease was also attributable to a decrease in ide-cel ex-

U.S. service revenue primarily due to overall lower manufacturing costs related costs incurred by us during the three months ended March 31, 2024.

Research and Development Expenses. Research and development expenses were $43.9 million for the three months ended March 31, 2024, compared to $68.2 million for the three months ended March 31, 2023. The overall decrease of $24.3 million was primarily attributable to the following:

•$13.3 million of decreased material production costs largely relating to increased manufacturing activities of suspension lentiviral vector for ide-cel development along with increased manufacturing activities of plasmids and cell banks in the first quarter of 2023;

•$8.5 million of decreased employee compensation primarily resulting from the 40% reduction to our workforce as part of our restructuring, effective as of September 2023 along with an additional reduction to our workforce in the first quarter of 2024; and

•$3.0 million of decreased license and milestone fees relating to fees associated with a milestone paid to Medigene for the continued development of our MAGE-A4 TCR program in solid tumors, which is being developed as part of our collaboration with Regeneron in the first quarter of 2023.

These decreases were partially offset by a $1.2 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 $3.3 million for the three months ended March 31, 2024, compared to $3.7 million for the three months ended March 31, 2023. The decrease of $0.4 million was primarily due to a decrease in quality testing performed by us on Abecma inventory during the first quarter of 2024.

Restructuring Expenses. The increase in restructuring expenses is a result of the costs associated with the reduction of the workforce as a part of our 2024 Restructuring Plan, effective as of January 2024.

Selling, General and Administrative Expenses. Selling, general and administrative expenses were $12.7 million for the three months ended March 31, 2024, compared to $20.7 million for the three months ended March 31, 2023. The decrease of $8.1 million was primarily due to the following:

•$6.3 million decrease primarily resulting from the 40% reduction to our workforce announced in September 2023 and the additional reduction to our workforce, announced in January 2024. The decrease was also driven by a decrease in stock-based compensation expense due to an overall decrease in the value of outstanding awards; and

•$4.2 million decrease in costs associated with terminations and settlements related to license agreements.

These decreases were offset by an increase of $2.7 million in consulting and professional service fees resulting from increased fees associated with the Asset Sale to Regeneron.

Share of Collaboration Loss. Share of collaboration loss for the three months ended March 31, 2024 represents our share of net loss arising from the commercialization of Abecma under the BMS collaboration during this period.

Cost of Royalty and Other Revenue. There is no cost of royalty and other revenue for the three months ended March 31, 2024, and total cost of royalty and other revenue was $0.6 million for the three months ended March 31, 2023. The decrease is due to the royalty term ending relating to Breyanzi in August of 2023.

Change in Fair Value of Contingent Consideration. The change in fair value of contingent consideration of $1.8 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.

Loss on assets held for sale

The loss on assets held for sale consists of fixed assets that ceased depreciation and measured at the lower of its carrying value or fair value less cost to sell.

Other Income, Net. For the three months ended March 31, 2024 and 2023 other income, net primarily consisted of rental income and income recognized under our transition service agreements with bluebird bio.

Liquidity and Capital Resources

As of March 31, 2024, we had cash, cash equivalents, and marketable securities of approximately $181.4 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 these financial statements. 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 includes the potential sale of shares of our 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 facility as of the date of this Quarterly Report on Form 10-Q. 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 three months ended March 31, 2024, we incurred a loss of $52.7 million and used $41.9 million of cash in operations. The Company expects to continue to generate operating losses and negative operating cash flows for the near future.

Sources of Liquidity

Cash Flows

The following table summarizes our cash flow activity:


	For the three months ended March 31,
	2024		2023
	(in thousands)
Net cash used in operating activities	$	(41,877)	$	(49,088)
Net cash provided by investing activities	21,833		44,798
Net cash provided by financing activities	386		127,084
(Decrease) increase in cash, cash equivalents and restricted cash and cash equivalents	$	(19,658)	$	122,794

Cash Flows from Operating Activities. Net cash used in operating activities was $41.9 million for the three months ended March 31, 2024 and primarily consisted of a net loss of $52.7 million adjusted for non-cash items, including stock-based compensation of $4.7 million, a non-cash loss on assets held for sale of $5.0 million, depreciation and amortization of $2.1 million, the change in fair value of contingent consideration of $1.7 million, other non-cash items of $1.3 million, as well as the change in our net working capital.

Net cash used in operating activities was $49.1 million for the three months ended March 31, 2023 and primarily consisted of net loss of $47.0 million adjusted for non-cash items, including stock-based compensation of $9.7 million and depreciation and amortization of $2.3 million, and the change in fair value of contingent consideration of $0.1 million, as well as the change in our net working capital.

Cash Flows from Investing Activities. Net cash provided by investing activities for the three months ended March 31, 2024 was $21.8 million and was due to proceeds from maturities of marketable securities of $40.0

million and proceeds from maturities of restricted investments of $5.0 million, offset by the purchase of marketable securities of $16.6 million, the purchase of restricted investments of $6.2 million, and the purchase of property, plant and equipment of $0.6 million.

Net cash provided by investing activities for the three months ended March 31, 2023 was $44.8 million and was due to proceeds from maturities of marketable securities of $87.0 million and proceeds from the maturities of restricted investments of $2.5 million, offset by the purchase of marketable securities of $36.1 million, the purchase of restricted investments of $2.5 million, and the purchase of property, plant and equipment of $6.1 million.

Cash Flows from Financing Activities. Net cash provided by financing activities for the three months ended March 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 three months ended March 31, 2023 was $127.1 million and was primarily due to net proceeds received of $117.1 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 advancement of Abecma into earlier lines of therapy and 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, timing and outcome of regulatory approvals for Abecma in earlier lines of therapy;

▪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 or future commercialization efforts, or grant rights to develop and market any future product candidates that we would otherwise prefer to develop and market ourselves.

Contractual Obligations and Commitments

In connection with the Asset Sale, 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 condensed consolidated financial statements included elsewhere in the Form 10-Q for further information regarding our future minimum commitments under ASC 842 under our operating leases and Note 18, Subsequent Events, for further information on the closing on the transaction with Regeneron. There have been no other material changes to our contractual obligations and commitments as included in our audited consolidated financial statements included in our 2023 annual report on Form 10-K.

Emerging Growth Company Statu

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 3. QUANTITATIVE AND QUALITATIVE DISCLOSURES ABOUT MARKET RISK

Interest rate fluctuation risk

We are exposed to market risk related to changes in interest rates. As of March 31, 2024, we had cash, cash equivalents and marketable securities of $181.4 million, primarily invested in U.S. government agency securities and treasuries and commercial paper. Our primary exposure to market risk is interest rate sensitivity, which is affected by changes in the general level of U.S. interest rates, particularly because our investments are in short-term securities. Our available for sale securities are subject to interest rate risk and will fall in value if market interest rates increase. If market interest rates were to increase immediately and uniformly by 100 basis points, or one percentage point, from levels at March 31, 2024, the net fair value of our interest-sensitive marketable securities and restricted investments would have resulted in a hypothetical decline of $0.8 million.

Foreign currency fluctuation risk

We are not currently exposed to significant market risk related to changes in foreign currency exchange rates; however, we have contracted with and may continue to contract with foreign vendors. Our operations may be subject to fluctuations in foreign currency exchange rates in the future.

Inflation fluctuation risk

Inflation generally affects us by increasing our cost of labor and operating expenses. We do not believe that inflation had a material effect on our business, financial condition or results of operations during the three months ended March 31, 2024. Although we do not believe that inflation has had a material impact on our financial position or results of operations to date, we may experience some effect in the near future (especially if inflation rates continue to rise) due to an impact on the costs to conduct clinical trials, labor costs we incur to attract and retain qualified personnel, and other operational costs, inflationary costs could adversely affect our business, financial condition and results of operations.

ITEM 4. CONTROLS AND PROCEDURES

Evaluation of Disclosure Controls and Procedures

As required by Rule 13a-15(b) of the Securities Exchange Act of 1934, as amended, or the Exchange Act, our management, including our principal executive officer and our principal financial officer, conducted an evaluation as of the end of the period covered by this Quarterly Report on Form 10-Q of the effectiveness of the design and operation of our disclosure controls and procedures. Based on that evaluation, our principal executive officer and principal financial officer concluded that our disclosure controls and procedures are effective at the reasonable assurance level in ensuring that information required to be disclosed by us in the reports that we file or submit under the Exchange Act is recorded, processed, summarized, and reporting within the time periods specified in the SEC’s rules and forms. Disclosure controls and procedures include, without limitation, controls and procedures designed to ensure that information required to be disclosed by us in the reports we file under the Exchange Act is accumulated and communicated to our management, including our principal executive officer, as appropriate to allow timely decisions regarding required disclosure.

Changes in Internal Control

There were no changes during the period covered by this Quarterly Report on Form 10-Q that have materially affected, or are reasonably likely to materially affect, our internal control over financial reporting.

PART II. OTHER INFORMATION

Item 1. Legal Proceedings

We are not a party to any material legal proceedings at this time. From time to time, we may be subject to various legal proceedings and claims, which may have a material adverse effect on our financial position or results of operations.

Item 1A. Risk Factors

There have been no material changes to the risk factors described in the section captioned “Part I, Item 1A. Risk Factors” in our annual report on Form 10-K for the year ended December 31, 2023. In addition to the other information set forth in this report, you should carefully consider the factors discussed in the section captioned “Part I, Item 1A. Risk Factors” in our annual report on Form 10-K for the year ended December 31, 2023, which could materially affect our business, financial condition, or future results. The risks described in our annual report on Form 10-K and our quarterly reports on Form 10-Q are not the only risks we face. Additional risks and uncertainties not currently known to us or that we currently deem to be immaterial also may have a material adverse effect on our business, financial condition, and/or operating results.

Item 2. Unregistered Sale of Equity Securities and Use of Proceeds

None

Item 3. Defaults Upon Senior Securities

None

Item 4. Mine Safety Disclosures

None

Item 5. Other Information

During the three months ended March 31, 2024, none of the directors or executive officers of the Company adopted, terminated or materially modified a trading plan intended to comply with Rule 10b5-1 or a trading plan not intended to comply with Rule 10b5-1.

Item 6. Exhibit Index


Exhibit Number						Exhibit Description
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).
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).
10.1*†						Asset Purchase Agreement between 2seventy bio, Inc. and Regeneron Pharmaceuticals, Inc., dated as of January 29, 2024.
10.2#						Transitional Services Agreement between 2seventy bio, Inc. and Nick Leschly, dated as of January 29, 2024 (incorporated by reference to Exhibit 10.1 to Current Report on Form 8-K filed on January 30, 2024).
10.3#						Executive Employment Agreement between 2seventy bio, Inc. and William Baird, dated as of January 29, 2024 (incorporated by reference to Exhibit 10.2 to Current Report on Form 8-K filed on January 30, 2024).
10.4#						Executive Employment Agreement between 2seventy bio, Inc. and Victoria Eatwell, dated as of January 29, 2024 (incorporated by reference to Exhibit 10.3 to Current Report on Form 8-K filed on January 30, 2024).
10.5#						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).
99.1						Press release issued by 2seventy bio, Inc. on January 30, 2024 (incorporated by reference to Exhibit 99.1 to Current Report on Form 8-K filed on January 30, 2024).
99.2						Press release issued by 2seventy bio, Inc. on March 15, 2024 (incorporated by reference to Exhibit 99.1 to Current Report on Form 8-K filed on March 18, 2024).
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.
101.INS*						Inline XBRL Instance Document
101.SCH*						Inline XBRL Taxonomy Extension Schema Document
101.CAL*						Inline XBRL Taxonomy Extension Calculation Linkbase Document
101.DEF*						Inline XBRL Taxonomy Extension Definition Linkbase Document
101.LAB*						Inline XBRL Taxonomy Extension Label Linkbase Document
101.PRE*						Inline XBRL Taxonomy Extension Presentation Linkbase Document
104*						Cover Page Interactive Data File (formatted as inline XBRL with applicable taxonomy extension information contained in Exhibits 101.*)

________________

* Filed herewith.

**The certifications furnished in Exhibit 32.1 hereto are deemed to accompany this Quarterly Report on Form 10-Q 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.

† Portions of this exhibit (indicated by asterisks) were omitted in accordance with the rules of the Securities and Exchange Commission.

# Indicates a management contract or compensatory plan, contract or arrangement.

SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, as amended, the registrant has duly caused this registration statement to be signed on its behalf by the undersigned, thereunto duly authorized.


	2seventy bio, Inc.

Date: May 9, 2024	By:	/s/ William Baird
		William Baird
		President and Chief Executive Officer (Principal Executive Officer and Duly Authorized Officer)

Date: May 9, 2024	By:	/s/ Victoria Eatwell
		Victoria Eatwell
		Chief Financial Officer
		(Principal Financial and Accounting Officer)