bluebird bio (BLUE) 10-K 13 Sep 24 2023 FY Annual report Financial data

Cover

Cover - USD ($)	12 Months Ended
	Dec. 31, 2023	Sep. 11, 2024	Jun. 30, 2023
Cover [Abstract]
Document Type	10-K
Document Annual Report	true
Document Period End Date	Dec. 31, 2023
Current Fiscal Year End Date	--12-31
Document Transition Report	false
Entity File Number	001-35966
Entity Registrant Name	bluebird bio, Inc.
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	13-3680878
Entity Address, Address Line One	455 Grand Union Boulevard
Entity Address, City or Town	Somerville
Entity Address, State or Province	MA
Entity Address, Postal Zip Code	02145
City Area Code	339
Local Phone Number	499-9300
Title of 12(b) Security	Common Stock, $0.01 par value per share
Trading Symbol	BLUE
Security Exchange Name	NASDAQ
Entity Well-known Seasoned Issuer	No
Entity Voluntary Filers	No
Entity Current Reporting Status	No
Entity Interactive Data Current	No
Entity Filer Category	Non-accelerated Filer
Entity Small Business	true
Entity Emerging Growth Company	false
ICFR Auditor Attestation Flag	false
Document Financial Statement Error Correction [Flag]	true
Document Financial Statement Restatement Recovery Analysis [Flag]	false
Entity Shell Company	false
Entity Public Float			$ 346,285,765
Entity Common Stock, Shares Outstanding		193,913,585
Documents Incorporated by Reference	DOCUMENTS INCORPORATED BY REFERENCE None.
Amendment Flag	false
Document Fiscal Year Focus	2023
Document Fiscal Period Focus	FY
Entity Central Index Key	0001293971

Audit Information

Audit Information	12 Months Ended
	Dec. 31, 2023
Audit Information [Abstract]
Auditor Firm ID	42
Auditor Name	Ernst & Young LLP
Auditor Location	Boston, Massachusetts

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2023	Sep. 30, 2023	Jun. 30, 2023	Mar. 31, 2023	Dec. 31, 2022	Sep. 30, 2022	Jun. 30, 2022	Mar. 31, 2022	Dec. 31, 2021
Current assets:
Cash and cash equivalents	$ 221,755				$ 113,006
Marketable securities	0				67,321
Prepaid expenses	14,800				8,618
Inventory	22,919				0
Receivables and other current assets	22,211				14,627
Total current assets	281,685				203,572
Marketable securities	0				1,414
Property, plant and equipment, net	65,936				67,636
Intangible assets, net	10,438				4,868
Goodwill	5,646				5,646
Operating lease right-of-use assets	201,113				230,885
Restricted cash and other non-current assets	54,343				55,793
Total assets	619,161				569,814
Current liabilities:
Accounts payable	18,498				14,867
Due to factor	2,520				0
Accrued expenses and other current liabilities	73,188				53,464
Operating lease liability, current portion	21,202				27,594
Finance lease liability, current portion	84,705				60,654
Total current liabilities	200,113				156,579
Operating lease liability, net of current portion	186,687				209,128
Finance lease liability, net of current portion	37,732				69,682
Other non-current liabilities	92				92
Total liabilities	424,624				435,481
Commitments and contingencies Note 12
Stockholders' equity:
Preferred stock, $0.01 par value, 5,000 shares authorized; 0 shares issued and    outstanding at December 31, 2023 and December 31, 2022	0				0
Common stock, $0.01 par value, 250,000 and 125,000 shares authorized; 192,772 and 82,923 shares issued and outstanding at December 31, 2023 and December 31, 2022, respectively	1,905				830
Additional paid-in capital	4,454,756				4,185,988
Accumulated other comprehensive loss	(1,796)				(4,070)
Accumulated deficit	(4,260,328)				(4,048,415)
Total stockholders' equity	194,537				134,333				$ 276,129
Total liabilities and stockholders' equity	$ 619,161				$ 569,814
Common stock, shares authorized (in shares)	250,000,000	250,000,000	250,000,000	125,000,000	125,000,000	125,000,000	125,000,000	125,000,000

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - $ / shares	Dec. 31, 2023	Sep. 30, 2023	Jun. 30, 2023	Mar. 31, 2023	Dec. 31, 2022	Sep. 30, 2022	Jun. 30, 2022	Mar. 31, 2022
Statement of Financial Position [Abstract]
Preferred stock, par value per share (in dollars per share)	$ 0.01	$ 0.01	$ 0.01	$ 0.01	$ 0.01	$ 0.01	$ 0.01	$ 0.01
Preferred stock, shares authorized (in shares)	5,000,000	5,000,000	5,000,000	5,000,000	5,000,000	5,000,000	5,000,000	5,000,000
Preferred stock, shares issued (in shares)	0	0	0	0	0	0	0	0
Preferred stock, shares outstanding (in shares)	0	0	0	0	0	0	0	0
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01	$ 0.01	$ 0.01	$ 0.01	$ 0.01	$ 0.01	$ 0.01
Common stock, shares authorized (in shares)	250,000,000	250,000,000	250,000,000	125,000,000	125,000,000	125,000,000	125,000,000	125,000,000
Common stock, shares issued (in shares)	192,772,000	107,022,000	106,454,000	106,370,000	82,923,000	82,880,000	73,551,000	71,438,000
Common stock, shares outstanding (in shares)	192,772,000	107,022,000	106,454,000	106,370,000	82,923,000	82,880,000	73,551,000	71,438,000

Consolidated Statements of Oper

Consolidated Statements of Operations and Comprehensive Loss - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Revenue:
Product revenue, net	$ 29,065	$ 2,739
Other revenue	432	858
Total revenues	29,497	3,597
Cost of product revenue	33,527	10,077
Gross margin	(4,030)	(6,480)
Operating expenses:
Selling, general and administrative	165,510	140,326
Research and development	167,652	200,439
Restructuring expense	0	4,940
Total operating expenses	333,162	345,705
Gain from sale of priority review voucher, net	92,930	102,000
Loss from operations	(244,262)	(250,185)
Interest income	9,869	1,032
Interest expense	(16,353)	(6,322)
Other income, net	38,707	25,250
Loss before income taxes	(212,039)	(230,225)
Income tax benefit (expense)	126	(117)
Net loss	$ (211,913)	$ (230,342)
Net income (loss) per share - basic (in dollars per share)	$ (1.93)	$ (2.93)
Net income (loss) per share - diluted (in dollars per share)	$ (1.93)	$ (2.93)
Weighted-average number of common shares used in computing net loss per share - basic (in shares)	109,825	78,585
Weighted-average number of common shares used in computing net loss per share - diluted (in shares)	109,825	78,585
Other comprehensive income (loss):
Other comprehensive income (loss)	$ 2,274	$ (1,159)
Comprehensive loss	$ (209,639)	$ (231,501)

Consolidated Statements of Op_2

Consolidated Statements of Operations and Comprehensive Loss (Parenthetical) - USD ($) $ in Millions

3 Months Ended

6 Months Ended

9 Months Ended

12 Months Ended

Sep. 30, 2023

Jun. 30, 2023

Mar. 31, 2023

Sep. 30, 2022

Jun. 30, 2022

Mar. 31, 2022

Jun. 30, 2023

Jun. 30, 2022

Sep. 30, 2023

Sep. 30, 2022

Dec. 31, 2023

Dec. 31, 2022

Income Statement [Abstract]

Other comprehensive income (loss), tax

$ 0

$ 0

$ 0

$ 0

$ 0

$ 0

$ 0

$ 0

$ 0

$ 0

$ 0

$ 0

Consolidated Statements of Stoc

Consolidated Statements of Stockholders' Equity - USD ($) $ in Thousands	Total	Common stock	Additional paid-in capital	Accumulated other comprehensive loss	Accumulated Deficit
Beginning balance (in shares) at Dec. 31, 2021		71,115,000
Beginning balance at Dec. 31, 2021	$ 276,129	$ 711	$ 4,096,402	$ (2,911)	$ (3,818,073)
Ending balance (in shares) at Mar. 31, 2022	71,438,000
Beginning balance (in shares) at Dec. 31, 2021		71,115,000
Beginning balance at Dec. 31, 2021	$ 276,129	$ 711	4,096,402	(2,911)	(3,818,073)
Ending balance (in shares) at Jun. 30, 2022	73,551,000
Beginning balance (in shares) at Dec. 31, 2021		71,115,000
Beginning balance at Dec. 31, 2021	$ 276,129	$ 711	4,096,402	(2,911)	(3,818,073)
Ending balance (in shares) at Sep. 30, 2022	82,880,000
Beginning balance (in shares) at Dec. 31, 2021		71,115,000
Beginning balance at Dec. 31, 2021	$ 276,129	$ 711	4,096,402	(2,911)	(3,818,073)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Vesting of restricted stock units (in shares)		979,000
Vesting of restricted stock units	0	$ 10	(10)
Exercise of stock options (in shares)		7,000
Exercise of stock options	16		16
Purchase of common stock under ESPP (in shares)		68,000
Purchase of common stock under ESPP	239	$ 1	238
Stock-based compensation	35,382		35,382
Issuance of common stock (in shares)		10,742,000
Issuance of common stock	54,067	$ 107	53,960
Issuance of unrestricted stock awards to settle accrued employee compensation (in shares)		12,000
Issuance of unrestricted stock awards to settle accrued employee compensation	1	$ 1
Other comprehensive gain (loss)	(1,159)			(1,159)
Net loss	$ (230,342)				(230,342)
Ending balance (in shares) at Dec. 31, 2022	82,923,000	82,923,000
Ending balance at Dec. 31, 2022	$ 134,333	$ 830	4,185,988	(4,070)	(4,048,415)
Beginning balance (in shares) at Mar. 31, 2022	71,438,000
Ending balance (in shares) at Jun. 30, 2022	73,551,000
Ending balance (in shares) at Sep. 30, 2022	82,880,000
Beginning balance (in shares) at Dec. 31, 2022	82,923,000	82,923,000
Ending balance (in shares) at Mar. 31, 2023	106,370,000
Beginning balance (in shares) at Dec. 31, 2022	82,923,000	82,923,000
Beginning balance at Dec. 31, 2022	$ 134,333	$ 830	4,185,988	(4,070)	(4,048,415)
Ending balance (in shares) at Jun. 30, 2023	106,454,000
Beginning balance (in shares) at Dec. 31, 2022	82,923,000	82,923,000
Beginning balance at Dec. 31, 2022	$ 134,333	$ 830	4,185,988	(4,070)	(4,048,415)
Ending balance (in shares) at Sep. 30, 2023	107,022,000
Beginning balance (in shares) at Dec. 31, 2022	82,923,000	82,923,000
Beginning balance at Dec. 31, 2022	$ 134,333	$ 830	4,185,988	(4,070)	(4,048,415)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Vesting of restricted stock units (in shares)		1,092,000
Vesting of restricted stock units	$ (196)	$ 10	(206)
Exercise of stock options (in shares)	3,000	24,000
Exercise of stock options	$ 92		92
Purchase of common stock under ESPP (in shares)		135,000
Purchase of common stock under ESPP	429	$ 2	427
Stock-based compensation	21,151		21,151
Issuance of common stock (in shares)		106,333,000
Issuance of common stock	248,367	$ 1,063	247,304
Exercise of warrants (in shares)		2,265,000
Other comprehensive gain (loss)	2,274			2,274
Net loss	$ (211,913)				(211,913)
Ending balance (in shares) at Dec. 31, 2023	192,772,000	192,772,000
Ending balance at Dec. 31, 2023	$ 194,537	$ 1,905	$ 4,454,756	$ (1,796)	$ (4,260,328)
Beginning balance (in shares) at Mar. 31, 2023	106,370,000
Ending balance (in shares) at Jun. 30, 2023	106,454,000
Ending balance (in shares) at Sep. 30, 2023	107,022,000

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Cash flows from operating activities:
Net loss	$ (211,913)	$ (230,342)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	28,525	8,344
Stock-based compensation expense	19,429	35,090
Noncash research and development expense (finance lease)	21,198	11,180
Noncash operating lease expense	29,772	23,562
Loss on fixed assets disposal	(92,930)	(102,000)
Unrealized loss (gain) on equity securities	0	3,135
Excess inventory reserve	15,363	7,519
Other non-cash items	24	4,138
Gain on foreign currency exchange rates	167	(1,801)
Proceeds from sale of accounts receivable	5,040	0
Changes in operating assets and liabilities:
Prepaid expenses and other assets	(3,894)	(4,820)
Inventory	(36,560)	(7,227)
Operating lease right-of-use assets		0
Accounts payable	2,841	(7,709)
Operating lease liabilities	(28,887)	(14,072)
Accrued expenses and other liabilities	13,353	(45,974)
Accrued interest payable under finance lease	3,426	4,758
Net cash used in operating activities	(235,046)	(316,219)
Cash flows from investing activities:
Purchase of property, plant and equipment	(4,189)	(8,208)
Purchases of marketable securities	(43,297)	0
Proceeds from maturities of marketable securities	108,521	131,445
Proceeds from sales of marketable securities	5,853	30,216
Purchase of intangible assets	(4,868)	(5,000)
Proceeds from sale of priority review voucher	92,930	102,000
Net cash provided by investing activities	154,950	250,453
Cash flows from financing activities:
Proceeds from public offering of common stock, net of issuance costs	248,198	54,237
Proceeds from the transfer of invoices	2,520	0
Principal payments on finance leases	(54,367)	(36,734)
Other financing activities	(103)	16
Net cash provided by financing activities	196,248	17,519
Increase (decrease) in cash, cash equivalents and restricted cash	116,152	(48,247)
Cash, cash equivalents and restricted cash at beginning of year	158,445	206,692
Cash, cash equivalents and restricted cash at end of year	274,597	158,445
Reconciliation of cash, cash equivalents and restricted cash:
Cash and cash equivalents	221,755	113,006
Restricted cash included in receivables and other current assets	9,202	1,502
Restricted cash included in restricted cash and other non-current assets	43,640	43,937
Total cash, cash equivalents and restricted cash	274,597	158,445
Supplemental cash flow disclosures:
Right-of-use assets obtained in exchange for operating lease liabilities	(708)	221,036
Purchases of property, plant and equipment included in accounts payable and accrued expenses	884	(3)
Purchases of intangible assets included in accrued expenses	1,221	0
Right-of-use assets obtained in exchange for finance lease liabilities	21,929	73,443
Offering expenses included in accounts payable and accrued expenses	964	170
Beneficiary interest obtained in transferred invoices	560	0
Cash paid (refunded) during the period for income taxes	$ (42)	$ 253

Description of the business

Description of the business	12 Months Ended
	Dec. 31, 2023
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Description of the business	Description of the business bluebird bio, Inc. (the “Company” or “bluebird”) was incorporated in Delaware on April 16, 1992, and is headquartered in Somerville, Massachusetts. The Company is a biotechnology company committed to researching, developing and commercializing potentially curative gene therapies for severe genetic diseases based on its proprietary lentiviral vector ("LVV") gene addition platform. Since its inception, the Company has devoted substantially all of its resources to its research and development efforts relating to its product candidates, and commercialization of its approved products, including activities to manufacture product candidates, conduct clinical studies of its product candidates, perform preclinical research to identify new product candidates, provide selling, general and administrative support for these operations and market and commercially manufacture and distribute its approved products. The Company’s programs in severe genetic diseases include ZYNTEGLO (betibeglogene autotemcel, also known as beti-cel) as a treatment for β-thalassemia; LYFGENIA (lovotibeglogene autotemcel, also known as lovo-cel) as a treatment for sickle cell disease ("SCD"); and SKYSONA (elivaldogene autotemcel, also known as eli-cel) as a treatment for cerebral adrenoleukodystrophy ("CALD"). On August 17, 2022, ZYNTEGLO was approved by the U.S. Food and Drug Administration (“FDA”) for the treatment of adult and pediatric patients with ß-thalassemia who require regular red blood cell transfusions. On September 16, 2022, the FDA granted Accelerated Approval of SKYSONA to slow the progression of neurologic dysfunction in boys 4-17 years of age with early, active CALD. On December 8, 2023, LYFGENIA was approved by the FDA for the treatment of patients 12 years of age or older with sickle cell disease and with a history of vaso-occlusive-events. In April 2022, the Board of Directors of the Company approved a comprehensive restructuring plan intended to reduce operating expenses and enhance the Company’s focus on achieving FDA approval for its programs in the U.S. As part of the restructuring, the Company reduced its workforce by approximately 30% across the second and third quarters of 2022. Refer to Note 19, Reduction in workforce , for more information on this restructuring. In June 2022, the Company entered into an Equity Distribution Agreement (the “Equity Distribution Agreement”) with Goldman Sachs & Co. LLC (“Goldman”) to sell shares of the Company’s common stock up to $75.0 million, from time to time, through an “at the market” equity offering program under which Goldman would act as manager. Under the Equity Distribution Agreement, the Company paid to Goldman a commission equal to up to 3.0% of the gross proceeds of any Common Stock sold through Goldman under the Equity Distribution Agreement. The Company terminated the Equity Distribution Agreement in August 2023. In August 2023, the Company entered into an Open Market Sales Agreement (the "Sales Agreement") with Jefferies LLC ("Jefferies") to sell shares of the Company’s common stock up to $125.0 million, from time to time, through an “at the market” equity offering program under which Jefferies will act as sales agent. As of December 31, 2023, the Company has made no sales pursuant to the Sales Agreement. In December 2023, the Company entered into an underwriting agreement (the “Underwriting Agreement”) with Goldman and J.P. Morgan Securities LLC, to sell 83.3 million shares of the Company's common stock. The Company received net proceeds of approximately $118.1 million. In March 2024, the Company entered into a five-year term loan facility agreement with Hercules Capital, Inc. to secure debt financing for up to $175 million, available in four tranches. Since its inception, the Company has incurred significant operating losses and negative operating cash flows. As of December 31, 2023, the Company had an accumulated deficit of $4.3 billion. During the twelve months ended December 31, 2023, the Company incurred a net loss of $211.9 million and used $235.0 million of cash in operations. As of December 31, 2023, the Company had cash and cash equivalents of $221.8 million. In accordance with Accounting Standards Codification (“ASC”) 205-40, Going Concern, the Company has evaluated whether there are conditions and events, considered in the aggregate, that raise substantial doubt about the Company’s ability to continue as a going concern within one year after the date the financial statements are issued. This evaluation initially does not take into consideration the potential mitigating effect of management’s plans that have not been fully implemented as of the date the financial statements are issued. When substantial doubt exists under this methodology, management evaluates whether the mitigating effect of its plans sufficiently alleviates substantial doubt about the Company’s ability to continue as a going concern. The mitigating effect of management’s plans, however, is only considered if both (1) it is probable that the plans will be effectively implemented within one year after the date that the financial statements are issued, and (2) it is probable that the plans, when implemented, will mitigate the relevant conditions or events that raise substantial doubt about the entity’s ability to continue as a going concern within one year after the date that these consolidated financial statements are issued. The Company's history of recurring operating losses and negative operating cash flows, its expectation to generate operating losses and negative operating cash flows, and the need for additional funding to support its planned operations raise substantial doubt regarding the Company’s ability to continue as a going concern for a period of one year after the date that these consolidated financial statements are issued. Management's plans to alleviate the conditions that raise substantial doubt include controlling spending, executing on commercial launch plans, and exploring additional financing options. Management has concluded the likelihood that its plan to successfully obtain sufficient funding from one or more of these sources, or adequately reduce expenditures, while reasonably possible, is less than probable. Accordingly, the Company has concluded that substantial doubt exists about the Company’s ability to continue as a going concern for a period of at least 12 months from the date of issuance of these consolidated financial statements. The Company has based the estimated cash needs on assumptions that may prove to be wrong, and its operating plan may change as a result of many factors currently unknown to it. As a result, the Company could deplete its capital resources sooner than it currently expects. Along with the Company's revenue from product sales, the Company expects to finance its future cash needs through the issuance of equity, or debt, or other alternative means. If the Company is unable to obtain funding on a timely basis, or if revenues from product sales are less than it has projected, the Company may be required to further revise its business plan and strategy, which may result in the Company significantly curtailing, delaying or discontinuing one or more of its research or development programs or the commercialization of any products or may result in the Company being unable to expand its operations or otherwise capitalize on its business opportunities. As a result, the Company's business, financial condition and results of operations could be materially affected. The accompanying financial statements have been prepared on a going concern basis, which contemplates the realization of assets and satisfaction of liabilities in the ordinary course of business. The financial statements do not include any adjustments relating to the recoverability and classification of recorded asset amounts or the amounts and classification of liabilities that might result from the outcome of the uncertainties described above.

Restatement of Previously Issue

Restatement of Previously Issued Financial Statements	12 Months Ended
	Dec. 31, 2023
Accounting Changes and Error Corrections [Abstract]
Restatement of Previously Issued Financial Statements	Restatement of Previously Issued Financial Statements The Company has restated its previously issued consolidated financial statements as of and for the year ended December 31, 2022, and its previously issued unaudited condensed consolidated financial information for each of the first three quarters of the years ended December 31, 2023 and 2022 in this Form 10-K. The restated unaudited condensed consolidated financial information is disclosed in Note 21, Quarterly Financial Information (Unaudited) . The Company has also restated impacted amounts within the notes to the consolidated financial statements, as applicable. Leases The Company identified errors pertaining to 1) the application of its accounting policy for the treatment of combining lease and non-lease components in arrangements that contain a lease, 2) the missed identification of embedded leases and improper accounting for its lease arrangements, including embedded leases and lease modifications, and 3) the misclassification of such embedded leases. The Company’s accounting policy is to combine lease and non-lease components in all agreements. The Company determined that it did not consistently combine such components in its arrangements with contract manufacturing organizations ("CMOs") and a contract testing organization ("CTO") and certain office and laboratory space agreements that contain a lease. Correctly combining lease and non-lease components on a consistent basis, correctly identifying embedded leases and lease modifications associated with a change in scope of lease or non-lease components, and correcting other accounting errors for all lease arrangements resulted in the following adjustments as of and for the year ended December 31, 2022: • Three embedded leases with CMOs that were incorrectly classified as operating leases were determined to be finance leases. As a result, property, plant and equipment (right-of-use finance lease assets), finance lease liabilities, and interest expense were understated and operating lease right-of-use assets, accounts payable and accrued expenses, operating lease liabilities and research and development expense were overstated. The impact to prepaid expenses, other non-current assets, and other income varied from period to period. • Two additional embedded finance leases were identified in existing CMO agreements and one additional embedded finance lease was identified in an existing CTO agreement. As a result, property, plant and equipment (right-of-use finance lease assets), finance lease liabilities, and interest expense were understated, accounts payable and accrued expenses were overstated, and on a net basis, research and development expense was understated. The impact to prepaid expenses and other income varied from period to period. • Minimum fixed payments for certain operating leases related to office and laboratory space were understated and sublease income was improperly classified within selling, general and administrative expense, which resulted in an understatement of operating lease right-of-use assets, operating lease liabilities, selling, general and administrative expense and other income. The impact to other current assets varied from period to period. • Right-of-use assets associated with finance leases used in performing research and development activities without alternative future use at lease commencement or upon lease modification were immediately expensed to research and development expense which is the primary driver of the $95.6 million adjusted to accumulated deficit as of December 31, 2021. Subsequent finance lease amortization costs are expensed as research and development until achievement of regulatory approval and a subsequent modification to the embedded lease occurs. • Reclassification of the principal portion of embedded finance lease payments as financing activities as well as other reclassifications of cash and non-cash activity within operating activities on the consolidated statement of cash flows. Other Adjustments In addition to the misstatements identified above, the Company has corrected other immaterial errors. These other errors are quantitatively and qualitatively immaterial, individually and in the aggregate. However, the Company has corrected these other errors as part of the correction for the material errors related to embedded leases. Impact of Restatement The following tables represent the as-restated consolidated balance sheet as of December 31, 2022, and the related consolidated statements of operations and comprehensive loss, stockholders’ equity and cash flows for the year ended December 31, 2022. These tables also present a reconciliation from the prior period as previously reported to the as-restated amounts. The amounts as previously reported for fiscal year 2022 were derived from the Annual Report on Form 10-K for the fiscal year ended December 31, 2022, filed on March 29, 2023. Consolidated Balance Sheet: As of December 31, 2022 (in thousands) As Previously Reported Adjustments to Leases Other Adjustments As Restated Assets Current assets: Cash and cash equivalents $ 113,006 $ — $ — $ 113,006 Marketable securities 67,321 — — 67,321 Prepaid expenses 8,374 244 — 8,618 Receivables and other current assets 10,787 3,840 — 14,627 Total current assets 199,488 4,084 — 203,572 Marketable securities 1,414 — — 1,414 Property, plant and equipment, net 9,362 58,585 (311) 67,636 Goodwill 5,646 — — 5,646 Intangible assets, net 4,868 — — 4,868 Operating lease right-of-use assets 281,996 (51,111) 230,885 Restricted cash and other non-current assets 52,128 3,665 — 55,793 Total assets $ 554,902 $ 15,223 $ (311) $ 569,814 Liabilities and Stockholders’ Equity Current Liabilities: Accounts payable $ 25,092 $ (10,225) $ — $ 14,867 Accrued expenses and other current liabilities 51,985 (520) 1,999 53,464 Operating lease liability, current portion 51,160 (23,566) — 27,594 Finance lease liability, current portion — 60,654 — 60,654 Total current liabilities 128,237 26,343 1,999 156,579 Operating lease liability, net of current portion 230,230 (21,102) — 209,128 Financing lease liability, net of current portion — 69,682 — 69,682 Other non-current liabilities 92 — — 92 Total liabilities 358,559 74,923 1,999 435,481 Commitments and contingencies (Note 12) Stockholders’ Equity: Preferred stock, $0.01 par value, 5,000 shares authorized; 0 shares issued and outstanding at December 31, 2022 $ — $ — $ — $ — Common stock, $0.01 par value, 125,000 shares authorized; 82,923 shares issued and outstanding at December 31, 2022 830 — — 830 Additional paid-in capital 4,186,086 — (98) 4,185,988 Accumulated other comprehensive loss (4,070) — — (4,070) Accumulated deficit (3,986,503) (59,700) (2,212) (4,048,415) Total stockholders’ equity 196,343 (59,700) (2,310) 134,333 Total liabilities and stockholders’ equity $ 554,902 $ 15,223 $ (311) $ 569,814 Consolidated Statement of Operations and Comprehensive Loss Year ended December 31, 2022 (in thousands, except per share amounts) As Previously Reported Adjustments to Leases Other Adjustments As Restated Revenue: Product revenue, net $ 2,739 $ — $ — $ 2,739 Other revenue 858 — — 858 Total revenues 3,597 — — 3,597 Cost of product revenue 10,077 — — 10,077 Gross margin (6,480) — — (6,480) Operating expenses: Research and development 240,764 (40,121) (204) 200,439 Selling, general and administrative 136,908 3,516 (98) 140,326 Restructuring expenses 4,940 — — 4,940 Total operating expenses 382,612 (36,605) (302) 345,705 Gain from sale of priority review voucher, net 102,000 — — 102,000 (Loss) Income from operations (287,092) 36,605 302 (250,185) Interest income 1,032 — — 1,032 Interest expense — (6,322) — (6,322) Other (expense) income, net 19,599 5,651 — 25,250 (Loss) income before income taxes (266,461) 35,934 302 (230,225) Income tax (expense) benefit (117) — — (117) Net (loss) income (266,578) 35,934 302 (230,342) Net (loss) income per share - basic $ (3.39) $ 0.46 $ — $ (2.93) Net (loss) income per share - diluted $ (3.39) $ 0.46 $ — $ (2.93) Weighted-average number of common shares used in computing net (loss) income per share - basic: 78,585 — — 78,585 Weighted-average number of common shares used in computing net (loss) income per share - diluted: 78,585 — — 78,585 Other comprehensive (loss) income: Other comprehensive (loss) income, net of tax (benefit) expense of $0.0 million for the year ended December 31, 2022 (1,159) — — (1,159) Total other comprehensive (loss) income (1,159) — — (1,159) Comprehensive (loss) income $ (267,737) $ 35,934 $ 302 $ (231,501) Consolidated Statement of Changes in Stockholders' Equity: Common stock Additional Accumulated Accumulated Total (in thousands) Shares Amount As Previously Reported Balances at December 31, 2021 71,115 $ 711 $ 4,096,402 $ (2,911) $ (3,719,925) $ 374,277 Vesting of restricted stock 979 10 (10) — — — Exercise of stock options 7 — 16 — — 16 Purchase of shares under ESPP 68 1 238 — — 239 Issuance of common stock 10,742 107 53,960 — — 54,067 Issuance of unrestricted stock awards to settle accrued employee compensation 12 1 — — — 1 Stock-based compensation expense — — 35,480 — — 35,480 Other comprehensive loss — — — (1,159) — (1,159) Net (loss) income — — — — (266,578) (266,578) Balances at December 31, 2022 82,923 $ 830 $ 4,186,086 $ (4,070) $ (3,986,503) $ 196,343 Adjustments to Leases Balances at December 31, 2021 — $ — $ — $ — $ (95,634) $ (95,634) Vesting of restricted stock — — — — — — Exercise of stock options — — — — — — Purchase of shares under ESPP — — — — — — Issuance of common stock — — — — — — Issuance of unrestricted stock awards to settle accrued employee compensation — — — — — — Stock-based compensation expense — — — — — — Other comprehensive loss — — — — — — Net (loss) income — — — — 35,934 35,934 Balances at December 31, 2022 — $ — $ — $ — $ (59,700) $ (59,700) Other Adjustments Balances at December 31, 2021 — — — — (2,514) (2,514) Vesting of restricted stock — — — — — — Exercise of stock options — — — — — — Purchase of shares under ESPP — — — — — — Issuance of common stock — — — — — — Issuance of unrestricted stock awards to settle accrued employee compensation — — — — — — Stock-based compensation expense — — (98) — — (98) Other comprehensive loss — — — — — — Net (loss) income — — — — 302 302 Balances at December 31, 2022 — $ — $ (98) $ — $ (2,212) $ (2,310) As Restated Balances at December 31, 2021 71,115 711 4,096,402 (2,911) (3,818,073) 276,129 Vesting of restricted stock 979 10 (10) — — — Exercise of stock options 7 — 16 — — 16 Purchase of shares under ESPP 68 1 238 — — 239 Issuance of common stock 10,742 107 53,960 — — 54,067 Issuance of unrestricted stock awards to settle accrued employee compensation 12 1 — — — 1 Stock-based compensation expense — — 35,382 — — 35,382 Other comprehensive loss — — — (1,159) — (1,159) Net (loss) income — — — — (230,342) (230,342) Balances at December 31, 2022 82,923 $ 830 $ 4,185,988 $ (4,070) $ (4,048,415) $ 134,333

Summary of significant accounti

Summary of significant accounting policies and basis of presentation	12 Months Ended
	Dec. 31, 2023
Accounting Policies [Abstract]
Summary of significant accounting policies and basis of presentation	Summary of significant accounting policies and basis of presentation Basis of presentation The Company's consolidated financial statements have been prepared in accordance with accounting principles generally accepted in the United States (“GAAP”). The accompanying consolidated financial statements include the accounts of the Company and its wholly owned or controlled subsidiaries. All intercompany accounts and transactions have been eliminated. Any reference in these notes to applicable guidance is meant to refer to the authoritative United States GAAP as included in the Accounting Standard Codification (“ASC”) and the Accounting Standards Updates (“ASUs”) of the Financial Accounting Standards Board (“FASB”). Amounts reported are computed based on thousands, except percentages, per share amounts, or as otherwise noted. As a result, certain totals may not sum due to rounding. Reclassification of Prior Year Presentation Certain prior year amounts have been reclassified to conform to the current year presentation. Specifically, interest expense has been reclassified from interest income to interest expense in the consolidated statement of operations and comprehensive loss. These reclassifications had no effect on the reported results of operations. Principles of consolidation The accompanying consolidated financial statements include the accounts of the Company and its wholly-owned subsidiaries. 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: the alternative future use of assets used in research and development activities, future undiscounted cash flows and subsequent fair value estimates used to assess potential and measure any impairment of long-lived assets, including goodwill and intangible assets, and the measurement of right-of-use assets and lease liabilities, gross-to-net revenue calculations, stock-based compensation expense, accrued expenses, income taxes, 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, and the assessment of the likelihood and magnitude of losses that may be sustained upon resolution of contingencies. Foreign currency translation The financial statements of the Company’s subsidiaries with functional currencies other than the U.S. dollar are translated into U.S. dollars using period-end exchange rates for assets and liabilities, historical exchange rates for stockholders’ equity and weighted average exchange rates for operating results. Translation gains and losses are included in other comprehensive income (loss) in stockholders’ equity. Foreign currency transaction gains and losses are included in other income, net in the results of operations. Segment information The Company operates in a single segment, focusing on researching, developing and commercializing potentially transformative gene therapies for severe genetic diseases. Consistent with its operational structure, its chief operating decision maker manages and allocates resources at a global, consolidated level. Therefore, results of the Company's operations are reported on a consolidated basis for purposes of segment reporting. All material long-lived assets of the Company reside in the United States. Cash and cash equivalents The Company considers all highly liquid investments purchased with original final maturities of 90 days or less from the date of purchase to be cash equivalents. Cash equivalents comprise marketable securities with maturities of less than 90 days when purchased. Cash equivalents are reported at fair value. Marketable securities The Company’s marketable securities are maintained by investment managers and consist of U.S. government agency securities and treasuries, equity securities, corporate bonds and commercial paper. Debt securities are carried at fair value with the unrealized gains and losses included in other comprehensive income (loss) as a component of stockholders’ equity until realized. Any premium arising at purchase is amortized to the earliest call date and any discount arising at purchase is accreted to maturity. Amortization and accretion of premiums and discounts are recorded in interest income, net. Equity securities with readily determinable fair values are also carried at fair value with unrealized gains and losses included in other income, net. Realized gains and losses on both debt and equity securities are determined using the specific identification method and are included in other income, net. The Company classifies equity securities with readily determinable fair values, which would be available for use in its current operations, as current assets even though the Company may not dispose of such marketable securities within the next 12 months. Equity securities are included in the balance of marketable securities on the Company's consolidated balance sheets. The Company classifies marketable securities with a remaining maturity when purchased of greater than three months as available-for-sale. Marketable securities with a remaining maturity date greater than one year are classified as non-current assets. Effective January 1, 2020, the Company adopted ASU 2016-13, Financial Instruments - Credit Losses (Topic 326): Measurement of Credit Losses on Financial Statements (“ASU 2016-13” or “ASC 326”), using the effective date method. As the Company had never recorded any other-than-temporary-impairment adjustments to its available-for-sale debt securities prior to the effective date, no transition provisions are applicable to the Company. The Company assesses its available-for-sale debt securities under the available-for-sale debt security impairment model in ASC 326 as of each reporting date in order to determine if a portion of any decline in fair value below carrying value recognized on its available-for-sale debt securities is the result of a credit loss. The Company records credit losses in the consolidated statements of operations and comprehensive loss as credit loss expense within other income, net, which is limited to the difference between the fair value and the amortized cost of the security. To date, the Company has not recorded any credit losses on its available-for-sale debt securities. Accrued interest receivable related to the Company's available-for-sale debt securities is presented within receivables and other current assets on the Company's consolidated balance sheets. The Company has elected the practical expedient available to exclude accrued interest receivable from both the fair value and the amortized cost basis of available-for-sale debt securities for the purposes of identifying and measuring any impairment. The Company writes off accrued interest receivable once it has determined that the asset is not realizable. Any write-offs of accrued interest receivable are recorded by reversing interest income, recognizing credit loss expense, or a combination of both. To date, the Company has not written off any accrued interest receivables associated with its marketable securities. Concentrations of counter-party and liquidity risk To reduce exposure to counter-party and liquidity risk, the Company maintains concentration limits across all of its overnight bank deposits. As of December 31, 2023, the Company’s restricted cash balances were held in bank deposits. The remaining balance of cash and cash equivalents are invested in money market funds, U.S. government agency securities and treasuries, and investment grade commercial paper in line with the company’s board approved investment policy. The Company has not experienced any credit losses on its deposits of cash and cash equivalents. Periodically, the Company reviews the credit risk of its deposits based on public information including credit agency reports and public financial reporting. Fair value of financial instruments The Company has certain financial assets and liabilities recorded at fair value which have been classified as Level 1, 2 or 3 within the fair value hierarchy as described in the accounting standards for fair value measurements: Level 1—Fair values are determined utilizing quoted prices (unadjusted) in active markets for identical assets or liabilities that the Company has the ability to access at the measurement date. Level 2—Fair values are determined utilizing quoted prices for identical or similar assets or liabilities in active markets or other market observable inputs such as interest rates, yield curves and foreign currency spot rates. Level 3—Prices or valuations that require inputs that are both significant to the fair value measurement and unobservable. To the extent that valuation is based on models or inputs that are less observable or unobservable in the market, the determination of fair value requires more judgment. Accordingly, the degree of judgment exercised by the Company in determining fair value is greatest for instruments categorized in Level 3. A financial instrument’s level within the fair value hierarchy is based on the lowest level of any input that is significant to the fair value measurement. Items measured at fair value on a recurring basis include marketable securities (see Note 5, Marketable securities, and Note 6, Fair value measurements ). The carrying amounts of accounts payable and accrued expenses approximate their fair values due to their short-term nature. Goodwill Goodwill represents the excess of the purchase price over the fair value of the net assets acquired when accounted for using the acquisition method of accounting for business combinations. Goodwill is not amortized but is evaluated for impairment within the Company’s single reporting unit on an annual basis, during the fourth quarter, or more frequently if an event occurs or circumstances change that would more-likely-than-not reduce the fair value of the Company’s reporting unit below its carrying amount. The Company performs a one-step quantitative test and records the amount of goodwill impairment, if any, as the excess of a reporting unit's carrying amount over its fair value, not to exceed the total amount of goodwill allocated to the reporting unit. The Company has not recognized any impairment charges related to goodwill to date. A significant sustained decrease in the Company’s common stock, may in the future be a potential indicator that all or a portion of our goodwill is impaired and may require a quantitative impairment assessment of the Company’s goodwill at an interim date, which may result in an impairment charge in future periods. While management cannot predict if or when future goodwill impairments may occur, an impairment could have material adverse effects on the Company’s financial condition, operating income, net assets, and/or the Company’s cost of, or access to, capital. Intangible assets, net Intangible assets, net consist of in-licensed rights with finite lives, net of accumulated amortization. The Company amortizes its intangible assets using the straight-line method over their estimated economic lives and periodically reviews for impairment. Property, plant and equipment Property, plant and equipment is stated at cost. Maintenance and repairs that do not improve or extend the lives of the respective assets are expensed to operations as incurred. Depreciation and amortization is calculated using the straight-line method over the estimated useful lives of the assets, which are as follows: Asset Estimated useful life Building 40 years Computer equipment and software 3 years Furniture and fixtures 5 years Laboratory equipment 3-5 years Finance lease right-of-use asset Shorter of the useful life or remaining lease term Leasehold improvements Shorter of the useful life or remaining lease term Impairment of long-lived assets The Company reviews long-lived assets when events or changes in circumstances indicate the carrying value of the assets may not be recoverable. Recoverability is measured by comparison of the book values of the assets to future net undiscounted cash flows that the assets are expected to generate. If such assets are considered to be impaired, the impairment to be recognized is measured by the amount by which the book value of the assets exceed their fair value, which is measured based on the projected discounted future net cash flows arising from the assets. Leases At the inception of an arrangement, the Company determines whether the arrangement is or contains a lease and its classification based on the unique facts and circumstances present in the arrangement. Leases with a term greater than one year are recognized on the balance sheet as right-of-use assets and current and non-current lease liabilities, as applicable. Right-of-use assets associated with finance leases used in the performance of research and development activities without alternative future use at lease commencement or at lease modification are immediately expensed to research and development expense pursuant to the guidance under ASC 730, Research and Development Costs. Lease liabilities and their corresponding right-of-use assets are initially recorded based on the present value of lease payments over the expected remaining lease term. Certain adjustments to the right-of-use asset may be required for items such as incentives received. The interest rate implicit in lease contracts is typically not readily determinable. As a result, the Company utilizes its incremental borrowing rate to discount lease payments, which reflects the fixed rate at which the Company could borrow on a collateralized basis the amount of the lease payments in the same currency, for a similar term, in a similar economic environment. To estimate its incremental borrowing rate, a credit rating applicable to the Company is estimated using a synthetic credit rating analysis since the Company does not currently have a rating agency-based credit rating. Subsequent to the initial measurement, the Company will continue to account for: • the lease liability at the net present value using the incremental borrowing rate that was in effect as of the lease commencement, lease modification, or transition date, and; • the finance lease right-of-use asset and operating lease expense on a straight line basis. The Company has elected not to recognize leases with an original term of one year or less on the balance sheet. The Company typically only includes an initial lease term in its assessment of a lease arrangement. Options to renew a lease are not included in the Company’s assessment unless there is reasonable certainty that the Company will renew. Assumptions made by the Company at the commencement date are re-evaluated upon occurrence of certain events, including a lease modification. A lease modification results in a separate contract when the modification changes the scope of or consideration for a lease or non-lease component under the agreement, such as when the lessor grants the lessee an additional right-of-use not included in the original lease and when lease payments increase commensurate with the standalone price for the additional right-of-use. When a lease modification results in a separate contract, it is accounted for in the same manner as a new lease. In accordance with ASC 842, components of a lease should be split into three categories: lease components, non-lease components, and non-components. The fixed and in-substance fixed contract consideration (including any consideration related to non-components) must be allocated based on the respective relative fair values to the lease components and non-lease components. Entities may elect not to separate lease and non-lease components. Rather, entities would account for each lease component and related non-lease component together as a single lease component. The Company has elected to account for lease and non- lease components together as a single lease component for real-estate leases and embedded CMO and CTO agreements and to allocate all the contract consideration to the lease component only, or to individual lease components on a relative standalone selling price basis when the lease terms associated with the individual lease components are not otherwise co-terminus. Lease modifications associated with embedded leases in contract manufacturing and testing arrangements arise with frequency based on the complexity of the gene therapy manufacturing processes and the related services provided by contract manufacturing and testing organizations, which are combined with lease components. The Company applies judgment in determining whether the contractual terms for the delivery of services represent a change in the scope or consideration of the arrangements, which are accounted for as lease modifications, or represent variable lease payments, which are recognized as incurred. ASC 842 allows for the use of judgment in determining whether the assumed lease term is for a major part of the remaining economic life of the underlying asset and whether the present value of lease payments represents substantially all of the fair value of the underlying asset. The Company applies the guidance in ASC 842-10-55-2 to assist in determining lease classification across its portfolio of leases. Inventory Inventories are stated at the lower of cost or net realizable value under the first-expired, first-out ("FEFO") methodology. Given human gene therapy products are a new and novel category of therapeutics and future economic benefit is not probable until regulatory approval for the product has been obtained, the Company has only considered inventory for capitalization upon regulatory approval. Manufacturing costs incurred prior to regulatory approval for pre-launch inventory that did not qualify for capitalization and clinical manufacturing costs are charged to research and development expense in the Company’s consolidated statements of operations and comprehensive loss as costs are incurred. Additionally, inventory that initially qualifies for capitalization but that may ultimately be used to produce clinical drug product is expensed as research and development expense when it has been designated for the manufacture of clinical drug product. Inventory consists of cell banks, plasmids, LVV, other materials and compounds sourced from third party suppliers and utilized in the manufacturing process, and drug product which has been produced for the treatment of specific patients, that are owned by the Company until infusion. Management periodically reviews inventories for excess or obsolescence, considering factors such as sales forecasts compared to quantities on-hand and firm purchase commitments as well as remaining shelf life of on-hand inventories. The Company writes down its inventory that is in excess, obsolete or otherwise unmarketable to its estimated net realizable value in the period in which the impairment is first identified. Any such adjustments are included as a component of cost of goods sold within cost of product revenue in the Company’s consolidated statements of operations and comprehensive loss. Revenue recognition Under ASC Topic 606, Revenue from Contracts with Customers (“Topic 606”), an entity recognizes revenue when its customer obtains control of promised goods or services, in an amount that reflects the consideration that the entity expects to receive in exchange for those goods or services. To determine revenue recognition for arrangements that an entity determines are within the scope of Topic 606, the entity performs the following five steps: (i) identify the contract(s) with a customer; (ii) identify the performance obligations in the contract; (iii) determine the transaction price, including variable consideration, if any; (iv) allocate the transaction price to the performance obligations in the contract; and (v) recognize revenue when (or as) the entity satisfies a performance obligation. The Company only applies the five-step model to contracts when it is probable that the entity will collect the consideration to which it is entitled in exchange for the goods or services it transfers to the customer. Once a contract is determined to be within the scope of Topic 606, the Company assesses the goods or services promised within each contract and determines those that are performance obligations. Arrangements that include rights to additional goods or services that are exercisable at a customer’s discretion are generally considered options. The Company assesses if these options provide a material right to the customer and if so, they are considered performance obligations. The Company assesses whether each promised good or service is distinct to identify the performance obligations in the contract. This assessment involves subjective determinations and requires management to make judgments about the individual promised goods or services and whether such are separable from the other aspects of the contractual relationship. Promised goods and services are considered distinct provided that: (i) the customer can benefit from the good or service either on its own or together with other resources that are readily available to the customer (that is, the good or service is capable of being distinct) and (ii) the entity’s promise to transfer the good or service to the customer is separately identifiable from other promises in the contract (that is, the promise to transfer the good or service is distinct within the context of the contract). The transaction price is then determined and allocated to the identified performance obligations in proportion to their standalone selling prices (“SSP”) on a relative SSP basis. SSP is determined at contract inception and is not updated to reflect changes between contract inception and when the performance obligations are satisfied. If the consideration promised in a contract includes a variable amount, the Company estimates the amount of consideration to which it will be entitled in exchange for transferring the promised goods or services to a customer. The Company determines the amount of variable consideration by using the expected value method or the most likely amount method. The Company includes the unconstrained amount of estimated variable consideration in the transaction price. The amount included in the transaction price is constrained to the amount for which it is probable that a significant reversal of cumulative revenue recognized will not occur. At the end of each subsequent reporting period, the Company re-evaluates the estimated variable consideration included in the transaction price and any related constraint, and if necessary, adjusts its estimate of the overall transaction price. Any such adjustments are recorded on a cumulative catch-up basis in the adjustment period. In determining the transaction price, the Company adjusts consideration for the effects of the time value of money if the timing of payments provides the Company with a significant benefit of financing. The Company does not assess whether a contract has a significant financing component if the expectation at contract inception is such that the period between payment by the licensees and the transfer of the promised goods or services to the licensees will be one year or less. The Company assessed each of its revenue generating arrangements to determine whether a significant financing component exists and concluded that a significant financing component does not exist in any of its arrangements. The Company then recognizes as revenue the amount of the transaction price that is allocated to the respective performance obligation when (or as) each performance obligation is satisfied, either at a point in time or over time, and if over time recognition is based on the use of an output or input method. Product revenue In 2022, the Company received approval of ZYNTEGLO and SKYSONA from the FDA. In 2023, the Company received approval of LYFGENIA from the FDA. The amount of revenue recognized by the Company is equal to the amount of consideration that is expected to be received from the sale of product to its customers. The Company uses Specialty Distributors ("SD") and Specialty Pharmacies ("SP") to deliver product to the Qualified Treatment Centers ("QTC"). Revenue is only recognized when the performance obligation is satisfied. The Company recognizes revenue upon infusion to the patient. To determine whether a significant reversal will occur in future periods, the Company will assess both the likelihood and magnitude of any such potential reversal of revenue. Gross product revenue is reduced by outcomes-based rebates, other rebates and distributor fees. Rebates expense Rebates are based on contractual arrangements or statutory requirements and include amounts due to Medicaid agencies and third-party payers. These amounts may vary by product and payer. Rebates are estimated primarily based on product sales, including product mix and pricing, historical and estimated payer mix and discount rates, among other inputs, which require significant estimates and judgment. The Company assesses and updates estimates each reporting period to reflect actual claims and other current information. Rebates that are payable to Medicaid agencies and third-party payers are recorded in accrued expenses and other current liabilities on the Company's consolidated balance sheets. Distributor fees The Company pays distribution fees to SDs and SPs in connection with the sales of our product. These distributor fees are based on a contractually determined fixed percentage of sales. Other revenue In 2021, the Company entered into a grant agreement with the Bill and Melinda Gates Foundation. The Company recognizes grant revenue in accordance with ASC 958-605, Revenue Recognition Not-for-Profit Entities , when qualifying costs are incurred and barriers to restriction have been overcome. When grant funds are received after costs have been incurred, the Company records revenue and a corresponding grant receivable. Cash received from grants in advance of incurring qualifying costs is recorded as deferred revenue and recognized as revenue when qualifying costs are incurred. In 2023, the Company ceased further research work and is in the process of winding down such collaboration. Factoring agreement In December 2023, the Company entered into a factoring agreement with a non-bank financial institution. The proceeds from the factoring agreement will be used to fund general working capital needs. The factoring agreement provides the Company access to up to $100.0 million on a revolving basis, measured by the outstanding balance of purchased accounts ("Purchased Accounts" as defined in the Invoice Purchase and Sales Agreement) sold on the purchase dates ("Purchase Dates" as defined in the Invoice Purchase and Sales Agreement) from time to time. The Company sells 100% of the invoice to Alterna Capital Solutions LLC, and the upfront purchase price for a Purchased Account is 90% of the invoice amount. The remaining 10% less applicable fees is payable only if and when Alterna Capital Solutions LLC receives full payment. The upfront payments are treated as a short-term liability, labeled as due to factor on our consolidated balance sheets. The short-term liability will be released upon infusion of the drug product. As of December 31, 2023, the balance in the due to factor account was $2.5 million. During December of 2023, the Company sold Purchased Accounts on the Purchase Dates to Alterna Capital Solutions LLC. The Purchased Assets are not available to our creditors to satisfy any of our obligations. Selling, general and administrative expenses Selling, general and administrative expenses are expensed as incurred. Selling, general and administrative expenses consist primarily of salaries and related costs for personnel, including stock-based compensation and travel expenses for the Company’s employees in executive, operational, finance, legal, business development, commercial, information technology, and human resource functions. Other selling, general and administrative expenses include facility-related costs, professional fees for accounting, tax, legal and consulting services, directors’ fees and expenses associated with obtaining and maintaining patents. The Company expenses the costs of advertising, which relates to advertising agency expenses, as incurred. Advertising expenses for the years ended December 31, 2023 and 2022 were immaterial. Research and development expenses Research and development costs are charged to expense as costs are incurred in performing research and development activities, including salaries and benefits, facilities costs, overhead costs, clinical study and related clinical manufacturing costs, CMO and CTO costs, contract research organization ("CRO") costs, license and milestone fees, contract services, manufacturing costs for pre-launch inventory that did not qualify for capitalization, and other related costs. Up-front fees and milestones paid to third parties in connection with technologies which have not reached technological feasibility and do not have an alternative future use are expensed as research and development expense as incurred. In circumstances where amounts have been paid in excess of costs incurred, the Company records a prepaid expense. The Company accrues costs for clinical trial activities based upon estimates of the services received and related expenses incurred that have yet to be invoiced by the contract research organizations, clinical study sites, laboratories, consultants, or other clinical trial vendors that perform the activities. Cost of product revenue All costs directly related to the manufacturing and delivery of the product to our qualified treatment centers are included in cost of product revenue which are associated with the sale of ZYNTEGLO and SKYSONA in the United States. Reserves for excess inventories are also included in cost of product revenue. Stock-based compensation The Company’s share-based compensation programs grant awards that have included stock options, restricted stock units, restricted stock awards, unrestricted stock awards and shares issued under its employee stock purchase plan. Grants are awarded to employees and non-employees, including the Company's board of directors. The Company accounts for its stock-based compensation awards in accordance with FASB ASC Topic 718, Compensation—Stock Compensation (“ASC 718”). ASC 718 requires all stock-based payments, including grants of stock options and restricted stock units and modifications to existing stock options, to be recognized in the consolidated statements of operations and comprehensive loss based on their fair values. The Company’s stock-based awards are subject to either service or performance-based vesting conditions. Compensation expense related to awards with service-based vesting conditions is recognized on a straight-line basis based on the grant date fair value over the associated service period of the award, which is generally the vesting term. Compensation expense related to awards with performance-based vesting conditions is recognized based on the grant date fair value over the requisite service period using the accelerated attribution method to the extent achievement of the performance condition is probable. The Company estimates the fair value of its option awards using the Black-Scholes option pricing model, which requires the input of subjective assumptions, including (i) the

Product revenue and reserves

Product revenue and reserves	12 Months Ended
	Dec. 31, 2023
Revenue from Contract with Customer [Abstract]
Product revenue and reserves	Product revenue and reserves For the years ended December 31, 2023 and 2022, the Company recorded $29.1 million and $2.7 million, respectively, of product revenue. Product revenue by therapy represents: For the year ended December 31, 2023 2022 ZYNTEGLO $ 16,692 $ 2,739 SKYSONA 12,373 — Total product revenue $ 29,065 $ 2,739 Two individual customers accounted for 49% and 35% of product revenue for the year ended December 31, 2023, and one individual customer accounted for 100% of product revenue for the year ended December 31, 2022. The Company considers there to be revenue concentration risks for customers that represent product revenues that exceed 10% of total product revenue. The concentration of the Company’s product revenue with a particular customer may have a material adverse effect on the Company’s revenue and results of operations if sales with the respective customer experience difficulties. All product revenue during 2023 and 2022 were within the United States and Europe, respectively. The following table summarizes an analysis of the change in reserves for gross to net deductions for the periods indicated: Total Balance at December 31, 2022 $ — Provision for rebates 5,365 Payments/credits — Balance at December 31, 2023 $ 5,365

Marketable securities

Marketable securities	12 Months Ended
	Dec. 31, 2023
Investments, Debt and Equity Securities [Abstract]
Marketable securities	Marketable securities The following table summarizes the marketable securities held at December 31, 2023 and 2022 (in thousands): Amortized cost / cost Unrealized gains Unrealized losses Fair value December 31, 2023 U.S. government agency securities and treasuries $ — $ — $ — $ — Total $ — $ — $ — $ — December 31, 2022 U.S. government agency securities and treasuries $ 67,970 $ — $ (1,733) $ 66,237 Corporate bonds 2,524 — (26) 2,498 Total $ 70,494 $ — $ (1,759) $ 68,735 No available-for-sale debt securities held as of December 31, 2022 had remaining maturities greater than five years.

Fair value measurements

Fair value measurements	12 Months Ended
	Dec. 31, 2023
Fair Value Disclosures [Abstract]
Fair value measurements	Fair value measurements The following table sets forth the Company’s assets and liabilities that are measured at fair value on a recurring basis as of December 31, 2023 and 2022 (in thousands): Total Quoted Significant Significant December 31, 2023 Assets: Cash and cash equivalents $ 221,755 $ 221,755 $ — $ — Marketable securities: U.S. government agency securities and treasuries — — — — Receivables and other current assets: Beneficiary interest in factored invoices 560 — — 560 Total assets $ 222,315 $ 221,755 $ — $ 560 December 31, 2022 Assets: Cash and cash equivalents $ 113,006 $ 113,006 $ — $ — Marketable securities: U.S. government agency securities and treasuries 66,237 — 66,237 — Corporate bonds 2,498 — 2,498 — Total assets $ 181,741 $ 113,006 $ 68,735 $ — Cash and cash equivalents As of December 31, 2023, cash and cash equivalents comprise funds in cash, money market accounts, and commercial paper. Marketable securities Marketable securities classified as Level 2 within the valuation hierarchy generally consist of U.S. government agency securities and treasuries, corporate bonds, and commercial paper. The Company estimates the fair value of these marketable securities by taking into consideration valuations obtained from third-party pricing sources. These pricing sources utilize industry standard valuation models, including both income and market-based approaches, for which all significant inputs are observable, either directly or indirectly, to estimate fair value. These inputs include market pricing based on real-time trade data for the same or similar securities, issuer credit spreads, benchmark yields, and other observable inputs. The Company validates the prices provided by its third-party pricing sources by understanding the models used, obtaining market values from other pricing sources and analyzing pricing data in certain instances. The amortized cost of available-for-sale debt securities is adjusted for amortization of premiums and accretion of discounts to the earliest call date for premiums or to maturity for discounts. At December 31, 2022, 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. There were $0.1 million, and no material realized losses recognized on the sale or maturity of available-for-sale securities during the years ended December 31, 2023 and 2022, respectively. Accrued interest receivable on the Company's available-for-sale debt securities totaled $0.3 million and $0.1 million as of December 31, 2023 and 2022, respectively. No accrued interest receivable was written off during the twelve months ended December 31, 2023 or 2022. The following table summarizes available-for-sale debt securities in a continuous unrealized loss position for less than and greater than twelve months, and for which an allowance for credit losses has not been recorded at December 31, 2023 and 2022 (in thousands): Less than 12 months 12 months or greater Total Description Fair value Unrealized losses Fair value Unrealized losses Fair value Unrealized losses December 31, 2023 U.S. government agency securities $ — $ — $ — $ — $ — $ — Total $ — $ — $ — $ — $ — $ — December 31, 2022 U.S. government agency securities $ — $ — $ 66,237 $ (1,733) $ 66,237 $ (1,733) Corporate bonds — — 2,498 (26) 2,498 (26) Total $ — $ — $ 68,735 $ (1,759) $ 68,735 $ (1,759) The Company determined that there was no material change in the credit risk of the above investments during the twelve months ended December 31, 2023. As such, an allowance for credit losses was not recognized. Factoring agreement Due from factor classified as Level 3 within the valuation hierarchy consists of beneficiary interest in transferred invoices. The Company estimates the fair value of the beneficiary interest based on the estimated cash flows after applying counterparty and credit risk adjustments associated with the factoring agent and distributors, respectively. As of December 31, 2023, no adjustment to the beneficiary interest in invoices sold was deemed an unobservable input and was determined based from ongoing credit evaluations and historical experience with aging of such invoices, among other factors. A significant change to this input could result in a significantly lower or higher fair value measurement. The following table shows a reconciliation of the beginning and ending balances for Level 3 financial liabilities measured at fair value on a recurring basis for the three months ended December 31, 2023: For the year ended December 31, 2023 Level 3 financial assets, beginning of period $ — Beneficiary interest obtained in transferred invoices 560 Proceeds from previously transferred invoices — Level 3 financial assets, end of period $ 560

Inventory

Inventory	12 Months Ended
	Dec. 31, 2023
Inventory Disclosure [Abstract]
Inventory	Inventory Inventory, net, consists of the following (in thousands): As of December 31, 2023 2022 Raw materials $ 2,329 $ — Work in progress 17,375 — Finished goods 3,215 — Inventory $ 22,919 $ — Raw materials inventory consists of completed materials purchased directly from third party suppliers. Work in progress inventory consists of materials manufactured at CMOs that are either partially completed, fully manufactured but are pending quality acceptance, or completed meeting quality acceptance standards to be used in the manufacture of drug product and drug products that are either partially completed or fully manufactured but are pending quality acceptance. Finished goods are completed and quality approved drug products that are either awaiting shipment, in-transit or delivered to a qualified treatment center, but have not yet been infused in a patient. As of December 31, 2022, the Company did not have any manufactured inventory that was in progress or had received final quality acceptance after the FDA approval of ZYNTEGLO, SKYSONA, or LYFGENIA. Prior to FDA approval, the existing inventory was expensed to research and development expense.

Property, plant and equipment,

Property, plant and equipment, net	12 Months Ended
	Dec. 31, 2023
Property, Plant and Equipment [Abstract]
Property, plant and equipment, net	Property, plant and equipment, net Property, plant and equipment, net, consists of the following (in thousands): As of December 31, 2023 2022 (As Restated) Finance lease right of use assets $ 84,524 $ 71,179 Laboratory equipment 14,636 21,048 Office equipment 4,767 4,323 Computer equipment and software 2,005 1,597 Leasehold improvements 1,251 — Construction-in-progress 563 — Total property, plant and equipment 107,746 98,147 Less accumulated depreciation and amortization (41,810) (30,511) Property, plant and equipment, net $ 65,936 $ 67,636

Restricted cash

Restricted cash	12 Months Ended
	Dec. 31, 2023
Other Assets, Noncurrent [Abstract]
Restricted cash	Restricted cash As of December 31, 2023 and 2022, the Company maintained letters of credit of $51.2 million and $43.9 million, respectively, which are collateralized with bank accounts at financial institutions in accordance with the agreements. Total restricted cash as of December 31, 2023 and 2022 consisted of the following (in thousands): As of December 31, 2023 2022 50 Binney Street lease $ 40,072 $ 40,072 Assembly Row lease 2,753 2,753 Embedded lease 7,632 — Other 2,385 2,614 Total restricted cash $ 52,842 $ 45,439 Refer to Note 11, Leases, for further information on the Company's letters of credit. The Company presents the current portion of restricted cash in receivables and other current assets.

Accrued expenses and other curr

Accrued expenses and other current liabilities	12 Months Ended
	Dec. 31, 2023
Payables and Accruals [Abstract]
Accrued expenses and other current liabilities	Accrued expenses and other current liabilities Accrued expenses and other current liabilities consist of the following (in thousands): As of December 31, 2023 2022 (As Restated) Accrued CMO and CRO costs $ 24,824 $ 17,369 Accrued employee compensation 19,972 20,095 Accrued goods and services 8,391 7,635 Accrued rebates 5,365 — Accrued refund liability 5,600 — Other 9,036 8,365 Total accrued expenses and other current liabilities $ 73,188 $ 53,464

Leases

Leases	12 Months Ended
	Dec. 31, 2023
Leases [Abstract]
Leases	Leases The Company leases certain office and laboratory space. Additionally, the Company entered into CMO and CTO agreements which have been determined to contain an embedded lease. Operating lease commitments 60 Binney Street lease & sublease In October 2021, the Company entered into a consent to assignment and amendment to its lease agreement for its 60 Binney Street lease (the "Assignment"). The Assignment transfers the Company's interest in the lease to 2seventy bio and releases the Company from its obligation to maintain the $13.8 million collateralized letter of credit required under the original 60 Binney Street lease. Although the lease was legally transferred to 2seventy bio, the lessor required that the Company remain secondarily liable as a guarantor for payment obligations accruing under the 60 Binney Street lease from the date of Assignment until the later of (i) the date that the Company has completely vacated the premises and (ii) the date that 2seventy bio has reached a market capitalization of $900 million. Upon Separation, the lease assignment was accounted for as the termination of the original lease and the Company de-recognized the right-of-use asset and lease liability related to the 60 Binney Street lease and recognized the fair value of the guarantee pursuant to ASC 405, Liabilities . The fair value of the guarantee was not material. Concurrent with the Assignment of the 60 Binney Street lease, the Company entered into a sublease agreement with 2seventy bio for office, laboratory and storage space located at 60 Binney Street (the "60 Binney Street Sublease") while it constructs and outfits its new office and laboratory space. The lease was modified in July 2022 to reflect the decreased use of the office and lab space. Under the terms of the 60 Binney Street Sublease, the Company leased 72,988 square feet for $1.0 million per month in base rent for the period beginning from the Assignment through March 2022 and 58,004 square feet for $0.8 million per month in base rent for the period from April 2022 through June 2022. Under the terms of the modification, beginning in July 2022, the Company is required to pay $0.6 million monthly until no later than December 2023. The Company also pays monthly fees for use of the facilities and support personnel, calculated based on its pro-rata share of operating costs during the term of the 60 Binney Street Sublease. The Company accounted for the 60 Binney Street Sublease as a new lease under ASC 842, and in November 2021, recognized a right-of-use asset and lease liability related to the 60 Binney Street Sublease. The Company terminated the 60 Binney Street Sublease in August 2023 and derecognized the right-of-use asset and lease liability. 50 Binney Street sublease & sub-sublease In April 2019, the Company entered into a sublease agreement for office space located at 50 Binney Street in Cambridge, Massachusetts (the “50 Binney Street Sublease”) to supplement the Company’s then-current corporate headquarters located at 60 Binney Street in Cambridge, Massachusetts. Under the terms of the 50 Binney Street Sublease, the Company leases 267,278 square feet of office space for $99.95 per square foot, or $26.7 million per year in base rent subject to certain operating expenses, taxes and annual rent increases of approximately 3%. The lease commenced in April 2022 and lease payments began in July 2022. The lease term will end on December 31, 2030, unless other specific circumstances specified in the 50 Binney Street Sublease occur. Upon signing the 50 Binney Street Sublease, the Company executed a $40.1 million cash-collateralized letter of credit, which may be reduced in the future subject to the terms of the 50 Binney Street Sublease and certain reduction requirements specified therein. The $40.1 million of cash collateralizing the letter of credit is classified as restricted cash and other non-current assets on the Company’s consolidated balance sheets. In December 2021, the Company entered into a sub-sublease agreement (the "Sub-Sublease") with Meta Platforms, Inc. (“Meta”). Under the terms of the Sub-Sublease, the Company is subleasing the entirety of the 50 Binney Street premises which it has rights to under the 50 Binney Street Sublease. The Company is sub-subleasing the premises for $29.4 million in the first year (inclusive of parking costs) with 3% annual increases in each subsequent year. Meta received access to 50 Binney Street at the lease commencement date, which is the same point that the Company received access under the 50 Binney Street Sublease. The Company remains liable under the 50 Binney Street Sublease, including for the maintenance of the $40.1 million collateralized letter of credit. The Company recognizes monthly sublease income of $2.6 million in other income, net for the sub-subleased space. Assembly Row lease In November 2021, the Company entered into a lease agreement with Assembly Row 5B, LLC ("Landlord") for office space located at 455 Grand Union Boulevard in Somerville, Massachusetts to serve as the Company's future corporate headquarters. Under the terms of the arrangement, the Company leases approximately 61,180 square feet starting at an annual rate of $45 per square foot, subject to annual increases of 2.5%, plus operating expenses and taxes. In addition, the Company is eligible to receive a tenant work allowance of $160 per rentable square foot of the premises. The lease commenced on March 1, 2022, the date on which the Landlord tendered possession of the premises to the Company with any tenant work required to be performed by the Landlord substantially completed. Since the lease commencement date, the Company has recognized rent expense of $0.3 million monthly. Hood Park lease In October 2022, the Company entered into a sublease with Finch Therapeutics, Inc. ("Finch") for office and laboratory space at Finch’s corporate headquarters located at 100 Hood Park Drive, Charlestown, Massachusetts. Under the terms of the arrangement, the Company leases 42,261 square feet for $55 per square foot, subject to annual increases of 3.0%, plus operating expenses and taxes. This sublease commenced December 15, 2022, the date on which the landlord tendered possession of the premises to the Company and is expected to terminate on December 14, 2025. Since the lease commencement date, the Company has recognized substantially all of the monthly $0.2 million costs as rent expense. Finance lease commitments - Embedded leases The Company has six embedded CMO and CTO arrangements. The details are noted below. Drug Product Manufacturing Embedded Lease No. 1: In June 2016, the Company entered into a manufacturing agreement for the future commercial production of the Company’s ZYNTEGLO and SKYSONA drug products with a CMO. Under this 12-year agreement, the CMO will complete the design, construction, validation and process validation of the leased suites prior to anticipated commercial launch of the product candidates. From 2016 through March 2018, while the suites were under construction, the Company paid a total of $12.0 million in contractual milestone payments. Construction was completed in March 2018, and beginning in April 2018, the Company paid $5.1 million per year, in fixed suite reservation fees as well as certain fixed labor, raw materials, testing and shipping costs for manufacturing services. The Company may terminate this agreement at any time upon payment of a one-time termination fee and up to 24 months of slot fees and 12 months of labor fees. The Company concluded that this agreement contains an embedded lease as the suites are designated for the Company’s exclusive use during the agreement's term, that it was not the deemed owner during construction, and the lease was not a capital lease under ASC 840-10, Leases - Overall. As a result, the Company initially accounted for the agreement as an operating lease under ASC 840 and recognized straight-line rent expense over the non-cancellable term of the embedded lease. As part of the Company's adoption of ASC 842, effective January 1, 2019, the Company carried forward the existing lease classification under ASC 840. The lease was modified and reclassified as a finance lease as of March 2019. In September 2023, the agreement was amended to change the fee structure in the arrangement from a fixed suite reservation fee to a fixed slot manufacturing fee. In addition, separate from the suite and existing equipment, the Company also has a forward starting embedded equipment lease that has not yet commenced. As the CMO is required to provide operational equipment throughout the contract term, the forward starting lease was established to account for the equipment that the CMO is obligated to lease to the Company in the future once the current equipment reaches its useful life and the lease expires. This forward starting lease is expected to commence in 2025 with an initial lease term of three years and has fixed commitments of approximately $54.5 million. The Company has prepaid approximately $3.7 million, which is accounted for as prepaid asset on the Company's balance sheet that would adjust the right-of-use asset when the forward starting embedded equipment lease commences in 2025. Embedded Lease No. 2: In November 2016, the Company entered into an agreement for clinical and commercial production of the Company’s ZYNTEGLO, SKYSONA, and LYFGENIA drug products with a CMO at an existing facility. The Company concluded that this agreement contains an embedded operating lease as the clean rooms are designated for the Company’s exclusive use during the agreement's term. The term of the agreement is five years with subsequent three-year renewals at the mutual option of each party. The Company recognized a right-of-use asset and lease liability and were recognizing rent expense on a straight-line basis throughout the estimated remaining term of the embedded lease upon effective date of ASC 842. In January 2019, the Company amended this agreement along with the execution of new work orders and additional contracts for the delivery of non-lease services from the CMO, resulting in a lease modification under ASC 842. Under the terms of the amended agreement, the Company is required to pay annual maintenance and production fees of up to €16.5 million, depending on its production needs, and may terminate this agreement with twelve months’ notice and a one-time termination fee. The amendment also provides for an option to reserve an additional clean room for a one-time option fee and annual maintenance fees. In connection with the lease modification, in April 2019, the Company reconsidered the lease classification and accounted for this embedded lease as a finance lease under ASC 842. In September 2021, the Company reassessed the term of this lease due to the planned orderly wind down of its operations in Europe, resulting in a reduction to the right-of-use asset and related lease liability to reflect the shortened expected term of the agreement. In November 2021, the Company exercised its right to terminate the lease agreement, effective in November 2022 and was required to pay a one-time termination fee of €1.0 million upon termination. That termination payment was made in December 2021. The Company also paid for services rendered through the date of termination based on work completed and expenses incurred prior to the date of termination. Embedded Lease No. 3: During July 2020, the Company amended an existing CMO arrangement to reserve additional manufacturing capacity for LYFGENIA. The Company concluded that this amendment contains an embedded lease as a controlled environment room at the facility is designated for the Company's exclusive use during the term of the agreement, with the option to sublease the space if the Company provides notice that it will not utilize it for a specified duration of time. Under the amended agreement, the Company is required to pay up to $5.4 million per year in maintenance fees in addition to the cost of any services provided and may terminate this agreement with eighteen months' notice. The term of the agreement is five years with the option to extend. when the additional manufacturing capacity became available that served as lease commencement in March 2021, the Company classified the embedded lease as a finance lease. In February 2021, the Company amended the CMO arrangement to reserve additional manufacturing capacity. The Company concluded that this amended agreement contains an embedded lease as a controlled environment room at the facility is designated for the Company's exclusive use during the agreement's term. Under the amended agreement, the Company must pay $4.2 million per year in maintenance fees and per-batch fees for the cost of any services provided. Either party may terminate this agreement with eighteen months’ notice at any time or with eight months’ notice after defined milestones in the agreement have been met. The term of the agreement is five years, with the option to extend. The lease commenced in November 2021 when the suites became available, and upon commencement the Company classified the embedded lease as a finance lease. The lease has been subsequently modified based on changes in the delivery of non-lease component services, which have been combined with lease components under our accounting policy. In August 2022, the Company amended another arrangement with this CMO to reserve additional controlled environmental rooms. The Company concluded that this amended agreement contains an embedded finance lease as the controlled environment room at the facility is designated for the Company's exclusive use during the agreement's term. Under the amended agreement, an existing deposit of $10.8 million was applied towards the monthly lease payments through September 2023. The term of the agreement was 14 months with an option to extend. The Company exercised the option to extend through December 31, 2023. Drug Substance Manufacturing Embedded Lease No. 4: In November 2017, the Company entered a commercial manufacturing services agreement with a CMO to establish commercial production of the Company's suspension vector. The Company concluded this agreement contained an embedded finance lease when production commenced in the new facility in 2019 as the Company has dedicated suite space and reserved production capacity at a rate that allows the Company to take more than substantially all the capacity of certain manufacturing space and equipment within the facility. Under the agreement, the Company must pay capacity reservation fees, minimum purchase commitment fees, and milestone fees for achievement of certain activities. In addition, the Company prepaid approximately €13.5 million between 2018 and 2019 towards certain milestone payments and in exchange for production credits. As of December 31, 2021, those credits have been fully used by the Company. The Company modified the lease to extend its term in October 2022, April 2023, and finally in October 2023, which extended the lease term to end in March 2024 in addition to changes in the delivery of non-lease component services, which have been combined with lease components under our accounting policy. Embedded Lease No. 5: In January 2018, the Company entered a clinical and commercial supply agreement with a CMO to manufacture ZYNTEGLO and SKYSONA vector products. The Company concluded this agreement contained an embedded finance lease. The Company and the CMO originally agreed to wind down manufacturing activities in December 2021. In December 2022, the Company reestablished this manufacturing agreement and concluded the revised arrangement contains an embedded finance lease as the Company is using the entire capacity of a manufacturing suite at the facility. The term of the agreement is three years and requires the Company to pay suite reservation fees of $13.5 million in 2023 and $18.0 million per year in 2024 and 2025, in addition to the cost of any services provided. Quality Testing Embedded Lease No. 6: In 2018, the Company entered a 2-year master contract services agreement (MCSA) with a CTO to provide clinical development services (other than manufacturing services). The original MCSA expired in June 2020 but was reinstated through December 2024 under the amendment of the MCSA effective April 2021. The Company concluded this agreement contained an embedded finance lease as the Company had certain lab suites implicitly dedicated to it for various clinical testing procedures. The Company is required to pay the fixed price outlined in each of the various service contracts covering quality, stability, and other services. The lease has been subsequently modified based on changes in the delivery of non-lease component services, which have been combined with lease components under our accounting policy. Summary of all lease costs recognized under ASC 842 The following table contains a summary of the lease costs recognized under ASC 842 and other information pertaining to the Company’s operating and finance leases for the years ended December 31, 2023 and 2022 (in thousands): For the year ended December 31, 2023 2022 (As Restated) Finance leases Interest expense $ 16,350 $ 6,324 Amortization expense 24,653 3,886 Total fixed finance lease cost $ 41,003 $ 10,210 Operating leases Fixed lease cost 43,272 36,122 Total fixed operating lease cost 43,272 36,122 Variable lease cost 22,960 28,161 Short-term lease cost 238 143 Total lease cost $ 107,473 $ 74,636 Operating sublease income $ 41,165 $ 29,369 Cash paid in the measurement of lease liabilities Operating cash flows used for operating leases $ 28,887 $ 14,072 Operating cash flows used for finance leases 12,924 1,551 Financing cash flows for finance leases 54,367 36,734 Other information Weighted average remaining lease term - finance leases (in years) 1.6 years 2.4 years Weighted average discount rate - finance leases 13.93 % 12.52 % Weighted average remaining lease term - operating leases (in years) 7.0 years 7.8 years Weighted average discount rate - operating leases 7.01 % 7.05 % For finance leases embedded in CMO arrangements, interest expense is recognized using the effective interest method, applying the Company's incremental borrowing rate as required by ASC 842, and amortization expense is recognized on a straight-line basis over the shorter of the life of the asset or the term of the lease. Rather than amortizing the finance lease right-of-use assets that did not have alternative future use, those amounts were recognized as research and development expense at lease commencement or lease modification and were $21.2 million and $11.2 million for the years ended December 31, 2023 and 2022, respectively. As of December 31, 2023, future minimum commitments under ASC 842 under the Company’s leases were as follows (in thousands): Operating Leases Financing Leases Remaining Lease Payments 2024 34,918 93,531 2025 37,084 34,995 2026 35,719 2,519 2027 36,742 2,519 2028 37,795 1,031 2029 and thereafter 81,986 — Total 264,244 134,595 Less: Imputed Interest (56,355) (12,158) Present Value of Lease Liabilities $ 207,889 $ 122,437

Commitments and contingencies

Commitments and contingencies	12 Months Ended
	Dec. 31, 2023
Commitments and Contingencies Disclosure [Abstract]
Commitments and contingencies	Commitments and contingencies Lease commitments The Company leases certain office and laboratory space and has embedded leases at CMOs and a CTO. As of December 31, 2023, the Company has commitments arising from a forward starting lease that has not yet commenced related to an embedded equipment lease with a CMO. This lease is expected to commence in 2025 with an initial lease term of three years. Fixed commitments under this contract approximate $54.5 million. The following table presents the non-cancelable contractual obligations arising from this arrangement (in thousands): Years ended December 31, Future commitment 2024 $ — 2025 11,959 2026 17,655 2027 17,655 2028 7,225 2029 and thereafter — Total purchase commitments $ 54,494 Refer to Note 11, Leases, for further information on the terms of these lease agreements. Litigation From time to time, the Company is party to various claims and complaints arising in the ordinary course of business, including securities class action litigation and intellectual property litigation. The Company enters into standard indemnification agreements in the ordinary course of business. Pursuant to the 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. 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 generally unlimited. Accruals for loss contingencies are recognized when a loss is probable, and the amount of such loss can be reasonably estimated. The Company has not accrued for a loss for any matter described below as a loss is not probable and a loss, or a range of loss, is not reasonably estimable. On March 28, 2024, a class action lawsuit captioned Garry Gill v. bluebird bio, Inc. et al., Case No. 1:24-cv-10803-PBS, was filed against the Company in the United States District Court for the District of Massachusetts. An amended complaint was filed on August 15, 2024. The amended complaint purports to assert claims against us and certain of the Company's current and former officers pursuant to Sections 10(b) and 20(a) of the Securities Exchange Act of 1934, as amended, and Rule 10b-5 promulgated thereunder, on behalf of a putative class of investors who purchased or otherwise acquired the Company’s shares between April 24, 2023 and December 8, 2023 (the “class period”). Plaintiff seeks to recover damages allegedly caused by purported misstatements and omissions regarding (i) whether the Company could obtain FDA approval for the lovo-cel BLA without a black box warning for hematologic malignancies; and (ii) whether the Company would be granted a priority review voucher by the FDA in connection with the BLA, which it could sell in order to strengthen its financial position. The amended complaint claims these alleged statements and omissions operated to artificially inflate the price paid for our common stock during the class period. On September 2, 2024, the Court entered the parties’ stipulated schedule for briefing a motion to dismiss the amended complaint: the opening brief in support of a motion to dismiss is due October 11, 2024; the opposition brief is due December 5, 2024; and a reply brief in further support of a motion to dismiss is due December 20, 2024. On June 27, 2024, a shareholder derivative lawsuit captioned Šimaitis v. Obenshain et al. , Case No. 1:24-cv-11674-PBS, was filed nominally on the Company's behalf against certain current and former members of Company management and the Board of Directors in the United States District Court for the District of Massachusetts. The complaint purports to assert derivative claims pursuant to Sections 10(b), 14(a), and 21D of the Securities Exchange Act of 1934, as well as for breach of fiduciary duties, unjust enrichment, waste of corporate assets, gross mismanagement, and abuse of control. Plaintiff seeks to recover damages on our behalf allegedly caused by purported materially false and misleading public statements and omissions, including in the April 28, 2023 proxy statement, regarding (i) whether the Company could obtain FDA approval for the lovo-cel BLA without a black box warning for hematologic malignancies; and (ii) whether the Company would be granted a priority review voucher by the FDA in connection with the BLA, which it could sell in order to strengthen its financial position. The complaint claims these allegedly misleading statements and omissions operated to artificially inflate the Company’s common stock price during the relevant time period. To support its derivative claims, the complaint alleges that a legally required pre-suit demand on the Board would be futile and should be excused. On July 25, 2024, the case was consolidated with Syracuse v. Obenshain et al. , Case No. 1:24-cv-11752 (D. Mass. July 8, 2024). The consolidated actions were recaptioned In re bluebird bio, Inc. Stockholder Derivative Litigation , Case No. 1:24-cv-11674-PBS. Parties must submit a scheduling order to the Court by September 23, 2024. On July 8, 2024, a shareholder derivative lawsuit captioned Syracuse v. Obenshain et al. , Case No. 1:24-cv-11752-PBS, was filed nominally on the Company's behalf against certain current and former members of Company management and the Board of Directors in the United States District Court for the District of Massachusetts. The complaint purports to assert derivative claims against pursuant to Section 14(a) of the Securities Exchange Act of 1934, as well as for breach of fiduciary duties, gross mismanagement, waste of corporate assets, and unjust enrichment. Plaintiff seeks to recover damages on our behalf allegedly caused by purported materially false and misleading public statements and omissions, including in the April 28, 2023 proxy statement, regarding (i) whether the Company could obtain FDA approval for the lovo-cel BLA without a black box warning for hematologic malignancies; and (ii) whether the Company would be granted a priority review voucher by the FDA in connection with the BLA, which it could sell in order to strengthen its financial position. The complaint claims these allegedly misleading statements and omissions operated to artificially inflate the Company’s common stock price during the relevant time period. To support its derivative claims, the complaint alleges that a legally required pre-suit demand on the Board would be futile and should be excused. On July 25, 2024, the case was consolidated with Šimaitis v. Obenshain et al. , Case No. 24-cv-11674 (D. Mass. July 27, 2024). The consolidated actions were recaptioned In re bluebird bio, Inc. Stockholder Derivative Litigation , Case No. 1:24-cv-11674-PBS. Parties must submit a scheduling order to the Court by September 23, 2024. The Company also indemnifies each of its officers and directors 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. The term of the indemnification period lasts as long as such officer or director may be subject to any proceeding arising out of acts or omissions of such officer or director in such capacity. The maximum amount of potential future indemnification is unlimited; however, the Company currently holds director and officer liability insurance. This insurance allows the transfer of risk associated with the Company's exposure and may enable it to recover a portion of any future amounts paid. The Company believes that the fair value of these indemnification obligations is minimal. Accordingly, it has not recognized any liabilities relating to these obligations.

Equity

Equity	12 Months Ended
	Dec. 31, 2023
Equity [Abstract]
Equity	Equity The Company is authorized to issue 250.0 million shares of common stock. Holders of common stock are entitled to one vote per share. Holders of common stock are entitled to receive dividends, if and when declared by the Company’s board of directors, and to share ratably in the Company’s assets legally available for distribution to the Company’s shareholders in the event of liquidation. Holders of common stock have no preemptive, subscription, redemption or conversion rights. As of December 31, 2023 and 2022, the Company had 192.8 million and 82.9 million shares of common stock issued and outstanding, respectively. In September 2021, the Company entered into an equity purchase agreement with certain investors, pursuant to which the Company agreed to sell and issue, in a private placement offering of securities, an aggregate of (i) 2.3 million shares of the Company’s common stock at a purchase price per share of $16.50 and (ii) pre-funded warrants to purchase up to 2.3 million shares of common stock (the “Pre-Funded Warrants”) at an effective price of $16.49 per share ($16.49 paid to the Company upon the closing of the offering and $0.01 to be paid upon exercise of such Pre-Funded Warrants). This resulted in aggregate gross proceeds to the Company of approximately $75.0 million. In October 2023, the investors opted to exercise their warrant. Pursuant to the terms of the warrant agreement, the company issued 2.3 million shares of common stock to the investor. As of December 31, 2023, there are no outstanding Pre-Funded Warrants. In June 2022, the Company entered into the Equity Distribution Agreement with Goldman to sell shares of the Company’s common stock, with aggregate gross sales proceeds of up to $75.0 million, from time to time, through an “at the market” equity offering program under which Goldman will act as manager. The Company terminated the Equity Distribution Agreement in August 2023. For the year ended December 31, 2022, the Company sold 10.7 million shares of common stock under the Equity Distribution Agreement for gross proceeds of $56.2 million ($54.2 million net of offering costs). On January 18, 2023, the Company entered into an underwriting agreement (the “January Underwriting Agreement”) with Goldman and J.P. Morgan Securities LLC in connection with the public offering, issuance, and sale by the Company of 20.0 million shares of the Company’s common stock at a public offering price of $6.00 per share, less underwriting discounts and commissions, pursuant to an effective shelf registration statement on Form S-3 and a related prospectus supplement filed with the Securities and Exchange Commission. Under the terms of the January Underwriting Agreement, the Company also granted the underwriters an option exercisable for 30 days to purchase up to an additional 3.0 million shares of common stock at the public offering price, less underwriting discounts and commissions, which option the underwriters exercised in full. The offering closed on January 23, 2023. The Company received aggregate net proceeds of $130.5 million. In August 2023, the Company entered into an Open Market Sales Agreement (the "Sales Agreement") with Jefferies LLC ("Jefferies") to sell shares of the Company’s common stock up to $125.0 million, from time to time, through an “at the market” equity offering program under which Jefferies will act as sales agent. As of December 31, 2023, the Company has made no sales pursuant to the Sales Agreement. On December 19, 2023, the Company entered into an underwriting agreement (the “December Underwriting Agreement”) with Goldman and J.P. Morgan Securities LLC, in connection with the public offering, issuance, and sale by the Company of 83.3 million shares of the Company’s common stock at a public offering price of $1.50 per share, less underwriting discounts and commissions, pursuant to an effective shelf registration statement on Form S-3 and a related prospectus supplement filed with the Securities and Exchange Commission. Under the terms of the December Underwriting Agreement, the Company also granted the underwriters an option exercisable for 30 days to purchase up to an additional 12.5 million shares of common stock at the public offering price, less underwriting discounts and commissions, which option was not exercised. The offering closed on December 22, 2023. The Company received aggregate net proceeds of $118.1 million. The Company is authorized to issue 5.0 million shares of preferred stock in one or more series and to fix the powers, designations, preferences and relative participating option or other rights thereof, including dividend rights, conversion rights, voting rights, redemption terms, liquidation preferences and the number of shares constituting any series, without any further vote or action by the Company’s shareholders. As of December 31, 2023 and 2022, the Company had no shares of preferred stock issued or outstanding.

Sale of Priority Review Voucher

Sale of Priority Review Vouchers	12 Months Ended
	Dec. 31, 2023
Discontinued Operations and Disposal Groups [Abstract]
Sale of Priority Review Vouchers	Sale of Priority Review Vouchers On November 29, 2022, the Company entered into an asset purchase agreement with argenx BV ("argenx"), pursuant to which the Company agreed to sell a Rare Pediatric Disease Priority Review Voucher (“PRV”) to argenx. The Company was awarded the voucher under an FDA program intended to encourage the development of certain rare pediatric disease product applications. The Company received the PRV when SKYSONA received accelerated approval by the FDA for the treatment of early, active CALD. Pursuant to the agreement, argenx agreed to pay the Company $102.0 million, payable in cash, upon the closing of the sale. The Company received a cash payment of $102.0 million upon closing on December 29, 2022, and there were no transaction costs associated with the sale.

Intangible assets

Intangible assets	12 Months Ended
	Dec. 31, 2023
Goodwill and Intangible Assets Disclosure [Abstract]
Intangible assets	Intangible assets Intangible assets, net of accumulated amortization, are summarized as follows (in thousands): As of December 31, 2023 Cost Accumulated amortization Impairment Net In-licensed rights 11,089 (651) — 10,438 Total $ 11,089 $ (651) $ — $ 10,438 As of December 31, 2022 Cost Accumulated amortization Impairment Net In-licensed rights 5,000 (132) — 4,868 Total $ 5,000 $ (132) $ — $ 4,868 Amortization expense for intangible assets was $0.5 million and $0.1 million for the years ended December 31, 2023 and 2022, respectively. In-licensed rights In-licensed rights consist of capitalized milestone payments made to third parties upon receiving regulatory approval of ZYNTEGLO, SKYSONA, and LYFGENIA in the U.S. The in-licensed rights are being amortized on a straight-line basis over the remaining life of the product exclusivity period in the U.S. of approximately twelve years per product, as the life of the product exclusivity reflects the expected time period that the Company will benefit from the in-licensed rights. The following table summarizes the estimated future amortization for intangible assets for the next five years and thereafter (in thousands): As of December 31, 2023 2024 $ 926 2025 926 2026 926 2027 926 2028 926 2029 and thereafter $ 5,808 Total $ 10,438

Stock-based compensation

Stock-based compensation	12 Months Ended
	Dec. 31, 2023
Share-Based Payment Arrangement [Abstract]
Stock-based compensation	Stock-based compensation 2023 Incentive Award Plan In June 2023, the Company’s stockholders approved the bluebird bio, Inc. 2023 Incentive Award Plan (“2023 Plan”), which became effective on June 16, 2023. The 2023 Plan replaced the 2013 Stock Option and Incentive Plan (“2013 Plan”). The 2023 Plan allows for the granting of incentive stock options, non-qualified stock options, restricted stock units, and restricted stock awards to the Company’s employees, members of the board of directors, and consultants of the Company. The 2023 Plan initially authorized the issuance of up to 5.2 million shares of common stock. Any awards outstanding under the Company’s 2013 Plan at the time of adoption of the 2023 Plan remained outstanding and effective. The shares of common stock underlying any awards that are forfeited, canceled, repurchased, expired or are otherwise terminated (other than by exercise) under the 2013 Plan are added to the shares of common stock available for issuance under the 2023 Plan. The 2023 Plan will expire in 2033. As of December 31, 2023, the total number of shares of common stock that may be issued under the 2023 Plan is 5.1 million. 2021 Inducement Plan On May 18, 2021, the Company's board of directors adopted the bluebird bio, Inc. 2021 Inducement Plan (the “Inducement Plan”) pursuant to the Nasdaq Stock Market LLC listing rules (“Rule 5635(c)(4)”). In accordance with Rule 5635(c)(4), equity-based incentive awards under the Inducement Plan may only be made to a newly hired employee who has not previously been a member of the Company's board of directors, or an employee who is being rehired following a bona fide period of non-employment by the Company as a material inducement to the employee’s entering into employment with the Company. The Inducement Plan initially reserved 600,000 shares, which was later increased to an aggregate of 1,250,000 shares in January 2022. The exercise price of stock options granted under the Inducement Plan will not be less than the fair market value of a share of the Company's common stock on the grant date. Other terms of awards, including vesting requirements, are determined by the Company's board of directors or compensation committee and are subject to the provisions of the Inducement Plan. Stock options granted to employees under the Inducement Plan generally vest over a four-year period but may be granted with different vesting terms. Certain options may provide for accelerated vesting in the event of a change in control. Stock options granted under the Inducement Plan expire no more than 10 years from the date of grant. As of December 31, 2023, 1.1 million shares of common stock are available for future grant under the Inducement Plan. 2013 Stock Option and Incentive Plan In June 2013, the Company’s board of directors adopted the 2013 Plan, which was subsequently approved by the Company's stockholders and became effective upon the closing of the Company’s IPO. The 2013 Plan expired in June 2023. The 2013 Plan allowed for the granting of incentive stock options, non-qualified stock options, restricted stock units and restricted stock awards to the Company’s employees, members of the board of directors, and consultants of the Company. The Company initially reserved approximately 1.0 million shares of its common stock for the issuance of awards under the 2013 Plan. The 2013 Plan provided that the number of shares reserved and available for issuance would automatically increase each January 1, beginning on January 1, 2014, by four percent of the outstanding number of shares of common stock on the immediately preceding December 31 or such lesser number of shares as determined by the Company’s compensation committee. In January 2023 and January 2022, the number of common stock available for issuance under the 2013 Plan was increased by approximately 2.8 million and 3.3 million shares, respectively, as a result of this automatic increase provision. Conversion and modification of equity awards outstanding at the Separation In connection with the Separation on November 4, 2021, under the provisions of the existing plans, the Company adjusted its outstanding equity awards in accordance with the terms of the Employee Matters Agreement (an equitable adjustment) to preserve the intrinsic value of the awards immediately before and after the distribution of all of the outstanding shares of 2seventy bio common stock to our stockholders. Upon the distribution, employees holding stock options, restricted stock units (“RSUs”) and performance restricted stock units (“PRSUs”) denominated in pre-distribution bluebird stock received a number of otherwise-similar awards either in post-Distribution bluebird stock or in a combination of post-distribution bluebird stock and 2seventy bio stock based on conversion ratios outlined for each group of employees in the Employee Matters Agreement that the Company entered into in connection with the distribution. The equity awards that were granted prior to 2021 were converted under the shareholder method, wherein employees holding outstanding equity awards received equity awards in both bluebird and 2seventy bio. The conversion ratio for the shareholder method took into consideration a distribution ratio of one share of 2seventy bio common stock for every three shares of bluebird common stock. For equity awards granted in 2021, the number of awards that were outstanding at the Separation were proportionately adjusted to maintain the aggregate intrinsic value of the awards at the date of the Separation. The conversion ratio was determined based on the volume weighted-average trading price for bluebird common stock for the five trading days before and after the Separation. These modified awards otherwise retained substantially the same terms and conditions, including term and vesting provisions. Additionally, bluebird will not incur any future compensation cost related to equity awards held by 2seventy bio employees and directors. The Company will incur future compensation cost related to 2seventy bio equity awards held by bluebird employees. Stock-based compensation expense The Company recognized stock-based compensation expense totaling $19.4 million and $35.1 million during the years ended December 31, 2023 and 2022, respectively. Stock-based compensation expense recognized by award type is as follows (in thousands): Year ended December 31, 2023 2022 (As Restated) Stock options $ 6,478 $ 14,168 Restricted stock units 12,619 20,138 Employee stock purchase plan and other 332 784 $ 19,429 $ 35,090 Stock-based compensation expense by classification included within the consolidated statements of operations and comprehensive loss was as follows (in thousands): Year ended December 31, 2023 2022 (As Restated) Cost of product revenue $ 881 $ — Selling, general and administrative 9,548 15,831 Research and development 9,000 19,259 $ 19,429 $ 35,090 During the years ended December 31, 2023 and 2022, the Company had $1.7 million and $0.3 million of stock-based compensation expense that was capitalized into inventory, respectively. As of December 31, 2023, the Company had $8.7 million and $18.8 million of unrecognized compensation expense related to unvested stock options and restricted stock units (exclusive of those with both service and performance conditions that have not yet been achieved), respectively, that is expected to be recognized over a weighted-average period of 1.96 years and 2.92 years, respectively. Stock options The fair value of each option issued to employees was estimated at the date of grant using the Black-Scholes option pricing model with the following weighted-average assumptions: Year ended December 31, 2023 2022 Expected volatility 70.9 % 66.4 % Expected term (in years) 6.10 6.0 Risk-free interest rate 4.1 % 1.9 % Expected dividend yield 0.0 % 0.0 % The following table summarizes the stock option activity under the Company’s equity awards plans excluding awards held by employees of 2seventy bio: Shares Weighted- Weighted- Aggregate Outstanding at December 31, 2022 2,668 $ 24.38 Granted 2,077 $ 4.89 Exercised (3) $ 2.74 Canceled or forfeited (515) $ 29.55 Outstanding at December 31, 2023 4,227 $ 14.16 8.06 $ — Exercisable at December 31, 2023 1,469 $ 28.80 6.54 $ — Vested and expected to vest at December 31, 2023 4,227 $ 14.16 8.06 $ — (a) The aggregate intrinsic value is calculated as the difference between the exercise price of the underlying options and the fair value of the common stock for the options that were in the money at December 31, 2023. The weighted-average fair values of options granted during the years ended December 31, 2023 and 2022 was $3.24 and $4.46, respectively. There was no intrinsic value of options exercised during the years ended December 31, 2023 and 2022, respectively. Restricted stock units The following table summarizes the restricted stock unit activity under the Company’s equity award plans excluding awards held by employees of 2seventy bio: Shares Weighted-average Unvested balance at December 31, 2022 2,415 $ 11.44 Granted 3,369 4.76 Vested (1,057) 14.35 Forfeited (520) 8.09 Unvested balance at December 31, 2023 4,207 $ 6.08 The intrinsic value of restricted stock units, including shares held by employees of 2seventy bio, vested during the years ended December 31, 2023 and 2022 was $5.4 million and $6.0 million, respectively. The total grant date fair value of restricted stock units vested during the years ended December 31, 2023 and December 31, 2022 was $15.2 million and $14.0 million, respectively. Employee Stock Purchase Plan In June 2013, the Company’s board of directors adopted its 2013 Employee Stock Purchase Plan (“2013 ESPP”), which was subsequently approved by its stockholders and became effective upon the closing of the Company’s IPO. The 2013 ESPP authorizes the initial issuance of up to a total of 0.2 million shares of the Company’s common stock to participating employees. In June 2021, the Company amended the 2013 ESPP to authorize an additional approximately 1.4 million shares of the Company’s common stock available to participating employees. During each of the years ended December 31, 2023 and 2022, approximately 0.1 million shares of common stock were issued under the 2013 ESPP.

401(k) Savings plan

401(k) Savings plan	12 Months Ended
	Dec. 31, 2023
Retirement Benefits [Abstract]
401(k) Savings plan	401(k) Savings plan In 1997, the Company established a defined-contribution savings plan under Section 401(k) of the Internal Revenue Code (the "401(k) Plan"). The 401(k) Plan covers all employees who meet defined minimum age and service requirements, and allows participants to defer a portion of their annual compensation on a pretax basis. Expense related to the 401(k) Plan from continuing operations totaled $3.1 million and $2.7 million for the years ended December 31, 2023 and 2022, respectively.

Income taxes

Income taxes	12 Months Ended
	Dec. 31, 2023
Income Tax Disclosure [Abstract]
Income taxes	Income taxes The components of loss before income taxes were as follows (in thousands): Year ended December 31, 2023 2022 (As Restated) U.S. $ (213,306) $ (230,160) Foreign 1,267 (65) Total $ (212,039) $ (230,225) The provision for (benefit from) income taxes were as follows (in thousands): Year ended December 31, 2023 2022 (As Restated) Current: Federal $ — $ — State — — Foreign (126) 117 Deferred: Federal — — State — — Foreign — — Total income tax expense (benefit) $ (126) $ 117 A reconciliation of income tax expense (benefit) computed at the statutory federal income tax rate to the Company’s effective income tax rate as reflected in the financial statements is as follows: Year ended December 31, 2023 2022 (As Restated) Federal income tax expense at statutory rate 21.0 % 21.0 % State income tax, net of federal benefit 7.3 % 5.2 % Permanent differences 0.6 % (0.1) % Stock-based compensation (3.6) % (9.3) % Research and development credit 5.8 % 8.3 % Leases 5.4 % 34.4 % Right-of-use assets — % (26.1) % Fixed assets (2.7) % (7.2) % Foreign differential — % 0.3 % Other 0.9 % (0.6) % Change in valuation allowance (34.6) % (26.0) % Effective income tax rate (expense) benefit 0.1 % (0.1) % For the years ended December 31, 2023 and 2022, the Company recognized an income tax expense (benefit) of $(0.1) million or 0.1% and $0.1 million or (0.1)%, respectively. The Company did not recognize any significant tax expense for the years ended December 31, 2023 or 2022 as the Company was subject to a full valuation allowance. Deferred taxes are recognized for temporary differences between the basis of assets and liabilities for financial statement and income tax purposes. The significant components of the Company’s deferred tax assets and liabilities are composed of the following (in thousands): Year ended December 31, 2023 2022 (As Restated) Deferred tax assets: U.S. net operating loss carryforwards (federal and state) $ 726,021 $ 713,557 Tax credit carryforwards (federal and state) 313,963 300,236 Capitalized license fees and research and development expenses 2,079 1,831 Capitalized research and development expenses under Section 174 91,306 54,885 Stock-based compensation 9,847 11,686 Lease liabilities 100,288 98,296 Accruals and other 20,336 17,325 Total deferred tax assets 1,263,840 1,197,816 Right-of-use assets (54,976) (61,388) Fixed assets (16,701) (17,536) Less valuation allowance (1,192,163) (1,118,892) Net deferred taxes $ — $ — 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. The valuation allowance increased on a net basis by approximately $73.3 million during the year ended December 31, 2023 due primarily to the capitalization of research and development credits that became effective in the 2022 tax year under the Tax Cuts and Jobs Act, net operating losses, and tax credit carryforwards. Effective January 1, 2021, the Company adopted ASU 2019-12, which simplifies accounting for income taxes. There was no material impact on the Company's financial position or results of operations upon adoption. As of December 31, 2023 and 2022, the Company had U.S. federal net operating loss carryforwards of approximately $2.7 billion and $2.7 billion, respectively, which may be available to offset future income tax liabilities. Of the amount as of December 31, 2023, $2.0 billion will carryforward indefinitely while $0.7 billion will expire at various dates through 2037. As of December 31, 2023 and 2022, the Company also had U.S. state net operating loss carryforwards of approximately $2.5 billion and $2.5 billion, respectively, which may be available to offset future income tax liabilities and expire at various dates through 2043. As of December 31, 2023 and 2022, the Company had federal research and development and orphan drug tax credit carryforwards of approximately $299.5 million and $285.6 million, respectively, available to reduce future tax liabilities which expire at various dates through 2043. As of December 31, 2023 and 2022, the Company had state credit carryforwards of approximately $18.3 million and $18.5 million, respectively, available to reduce future tax liabilities which expire at various dates through 2037. During the fourth quarter of 2018, the Company completed an analysis of prior year estimates of U.S. research and development and orphan drug tax credits for the years 2013 through 2017. The analysis resulted in an immaterial adjustment to the Company's income tax benefit, which was offset by an adjustment to the valuation allowance. An analysis of the U.S. research and development and orphan drug credits has not yet been completed for years 2018 through 2023. As of December 31, 2023 and 2022, the Company had capital loss carryforwards of approximately $4.2 million and $4.2 million, respectively, which may be available to offset future capital gains and will begin to expire in 2027. In March 2021, the American Rescue Plan Act ("ARPA") was enacted and contained extenders to the refundable employee retention credit and provided further limitations to executive compensation effective for tax years beginning after 2026. In August 2022, the Inflation Reduction Act (“IRA”) was enacted and introduced a 15% corporate alternative minimum tax (“CAMT”) for corporations with average annual adjusted financial statement income for any three-year tax period ending after December 31, 2021 and preceding tax year exceeding $1 billion, effective for tax years beginning after December 31, 2021, as well as a 1% excise tax on stock repurchases made by public companies, climate and energy provisions, and extensions to the Affordable Care Act subsidies. The Company has concluded that the provisions in the ARPA and IRA have an immaterial impact on the Company’s income tax expense due to its cumulative losses and full valuation allowance position. Under the provisions of the Internal Revenue Code, the net operating loss and tax credit carryforwards are subject to review and possible adjustment by the Internal Revenue Service and state tax authorities. Net operating loss and tax credit carryforwards may become subject to an annual limitation in the event of certain cumulative changes in the ownership interest of significant shareholders over a three-year period in excess of 50 percent, as defined under Sections 382 and 383 of the Internal Revenue Code, respectively, as well as similar state provisions. This could limit the amount of tax attributes that can be utilized annually to offset future taxable income or tax liabilities. The amount of the annual limitation is determined based on the value of the Company immediately prior to the ownership change. Subsequent ownership changes may further affect the limitation in future years. The Company has completed several financings since its inception and prior to its initial public offering in 2013, which it believes has resulted in a change in control as defined by Sections 382 and 383 of the Internal Revenue Code. The Company completed a study through December 2023 confirming no ownership changes have occurred since the Company's initial public offering in 2013; any ownership shifts occurring after December 2023 could result in an ownership change under Section 382. There is a significant likelihood that the Company may experience an ownership change as a result of future equity offerings, including any sales under the ATM program, although whether the Company experiences an ownership change will depend on the specific facts that apply at the time of any offering. The Company files Federal income tax returns in the United States, and various state and foreign jurisdictions. The federal, state and foreign income tax returns are generally subject to tax examinations for the tax years ended December 31, 2020 through December 31, 2022. To the extent the Company has tax attribute carryforwards, the tax years in which the attribute was generated may still be adjusted upon examination by the Internal Revenue Service, or state or foreign tax authorities to the extent utilized in a future period. A reconciliation of the beginning and ending amount of unrecognized tax benefits is as follows (in thousands): Unrecognized tax benefits Balance as of December 31, 2021 (As Restated) $ 21,956 Increases (decreases) for tax positions related to current period 1,582 Increases (decreases) for tax positions related to prior periods (45) Balance as of December 31, 2022 (As Restated) 23,493 Increases (decreases) for tax positions related to current period 944 Increases (decreases) for tax positions related to prior periods 101 Balance as of December 31, 2023 24,538 The unrecognized tax benefits at December 31, 2023, if recognized, would not affect the Company’s effective tax rate due to its full valuation allowance position. The Company does not anticipate that the amount of existing unrecognized tax benefits will significantly increase or decrease within the next 12 months. The Company has elected to include interest and penalties related to uncertain tax positions as a component of its provision for income taxes. For the years ended December 31, 2023 and 2022, the Company’s accrued interest and penalties related to uncertain tax positions were not material.

Reduction in workforce

Reduction in workforce	12 Months Ended
	Dec. 31, 2023
Restructuring and Related Activities [Abstract]
Reduction in workforce	Reduction in workforce In April 2022, the Board of Directors of the Company approved a comprehensive restructuring plan intended to reduce operating expenses. As part of the restructuring, the Company reduced its workforce by approximately 30% across the second and third quarters of 2022. The Company incurred approximately $4.9 million in costs to implement the restructuring, comprised primarily of severance payments and continuing health care coverage over the severance period. The restructuring actions associated with these charges commenced in April 2022, and were completed by September 30, 2022. The following tables summarizes the accrued liabilities activity recorded in connection with the reduction in workforce for the year ended December 31, 2022 (in thousands): Restructuring Expenses in 2022 Amounts paid in 2022 April 2022 reduction 4,940 (4,940) Total 4,940 (4,940)

Net loss per share

Net loss per share	12 Months Ended
	Dec. 31, 2023
Earnings Per Share [Abstract]
Net loss per share	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): Year ended December 31, 2023 2022 Outstanding stock options (1) 5,860 4,429 Restricted stock units (1) 4,239 2,524 Warrants 12,450 — ESPP shares and other 90 63 22,639 7,016 (1) Outstanding stock options and restricted stock units include awards outstanding to employees of 2seventy bio.

Quarterly Financial Information

Quarterly Financial Information (Unaudited)	12 Months Ended
	Dec. 31, 2023
Quarterly Financial Information Disclosure [Abstract]
Quarterly Financial Information (Unaudited)	Quarterly Financial Information (Unaudited) As further described in Note 2, the previously reported unaudited condensed consolidated financial information for the three months ended March 31, 2023 and 2022, the three and six months ended June 30, 2023 and 2022 and the three and nine months ended September 30, 2023 and 2022 are required to be restated. The as-restated interim financial information for each relevant period is included in the tables that follow. As part of the restatement, the Company recorded adjustments to correct the misstatements in the impacted interim periods. Descriptions of the lease entries which drove the restatement and other immaterial entries also recorded can be found in Note 2. For the interim periods in the nine months ended September 30, 2023, following the commercialization of ZYNTEGLO and SKYSONA, the embedded lease adjustments for certain CMOs and the CTO also impact inventory and cost of product revenue. The unaudited condensed consolidated financial information reflect all adjustments which are, in the opinion of management, necessary for a fair statement of the results for the interim periods presented. Restated amounts are computed independently each quarter; therefore, the sum of the quarterly amounts may not equal the total amount for the respective year due to rounding. Condensed Consolidated Balance Sheets The following unaudited condensed consolidated balance sheet tables present the impacts of the restatement adjustments as of the periods ended March 31, 2023 and 2022, June 30, 2023 and 2022, and September 30, 2023 and 2022. The period ended December 31, 2023 was not subject to restatement. As of March 31, 2023 (in thousands) As Previously Reported Adjustments to Leases Other Adjustments As Restated Assets Current assets: Cash and cash equivalents $ 239,045 $ — $ — $ 239,045 Marketable securities 79,212 — — 79,212 Prepaid expenses 13,466 (2,082) — 11,384 Inventory 3,809 (610) — 3,199 Receivables and other current assets 15,539 3,374 (2,800) 16,113 Total current assets 351,071 682 (2,800) 348,953 Property, plant and equipment, net 8,718 53,223 (270) 61,671 Goodwill 5,646 — — 5,646 Intangible assets, net 5,613 — — 5,613 Operating lease right-of-use assets 270,153 (46,690) — 223,463 Restricted cash and other non-current assets 51,535 3,665 — 55,200 Total assets $ 692,736 $ 10,880 $ (3,070) $ 700,546 Liabilities and Stockholders’ Equity Current Liabilities: Accounts payable $ 19,235 $ (2,522) $ — $ 16,713 Accrued expenses and other current liabilities 45,294 1,017 (801) 45,510 Operating lease liability, current portion 51,404 (24,784) 26,620 Financing lease liability, current portion — 58,747 — 58,747 Total current liabilities 115,933 32,458 (801) 147,590 Operating lease liability, net of current portion 221,971 (18,176) 203,795 Financing lease liability, net of current portion — 58,649 — 58,649 Other non-current liabilities 92 — — 92 Total liabilities 337,996 72,931 (801) 410,126 Commitments and contingencies (Note 12) Stockholders’ Equity: Preferred stock, $0.01 par value, 5,000 shares authorized; 0 shares issued and outstanding at March 31, 2023 $ — $ — $ — $ — Common stock, $0.01 par value, 125,000 shares authorized; 106,370 shares issued and outstanding at March 31, 2023 1,064 — — 1,064 Additional paid-in capital 4,322,025 — (98) 4,321,927 Accumulated other comprehensive loss (3,086) — — (3,086) Accumulated deficit (3,965,263) (62,051) (2,171) (4,029,485) Total stockholders’ equity 354,740 (62,051) (2,269) 290,420 Total liabilities and stockholders’ equity $ 692,736 $ 10,880 $ (3,070) $ 700,546 As of June 30, 2023 (in thousands) As Previously Reported Adjustments to Leases Other Adjustments As Restated Assets Current assets: Cash and cash equivalents $ 172,872 $ — $ — $ 172,872 Marketable securities 72,431 — — 72,431 Prepaid expenses 13,597 (2,162) — 11,435 Inventory 13,642 (1,838) 602 12,406 Receivables and other current assets 15,435 3,659 19,094 Total current assets 287,977 (341) 602 288,238 Property, plant and equipment, net 10,227 51,722 (235) 61,714 Goodwill 5,646 — — 5,646 Intangible assets, net 5,490 — — 5,490 Operating lease right-of-use assets 302,849 (86,929) 215,920 Restricted cash and other non-current assets 51,204 3,665 — 54,869 Total assets $ 663,393 $ (31,883) $ 367 $ 631,877 Liabilities and Stockholders’ Equity Current Liabilities: Accounts payable $ 10,894 $ (1,081) $ — $ 9,813 Accrued expenses and other current liabilities 56,531 (599) 1,999 57,931 Operating lease liability, current portion 67,591 (42,427) — 25,164 Financing lease liability, current portion — 55,706 — 55,706 Total current liabilities 135,016 11,599 1,999 148,614 Operating lease liability, net of current portion 239,266 (40,930) 198,336 Financing lease liability, net of current portion — 50,017 — 50,017 Other non-current liabilities 92 — — 92 Total liabilities 374,374 20,686 1,999 397,059 Commitments and contingencies (Note 12) Stockholders’ Equity: Preferred stock, $0.01 par value, 5,000 shares authorized; 0 shares issued and outstanding at June 30, 2023 $ — $ — $ — $ — Common stock, $0.01 par value, 250,000 shares authorized; 106,454 shares issued and outstanding at June 30, 2023 1,065 — — 1,065 Additional paid-in capital 4,328,489 — (98) 4,328,391 Accumulated other comprehensive loss (2,364) — — (2,364) Accumulated deficit (4,038,171) (52,569) (1,534) (4,092,274) Total stockholders’ equity 289,019 (52,569) (1,632) 234,818 Total liabilities and stockholders’ equity $ 663,393 $ (31,883) $ 367 $ 631,877 As of September 30, 2023 (in thousands) As Previously Reported Adjustments to Leases Other Adjustments As Restated Assets Current assets: Cash and cash equivalents $ 165,347 $ — $ — $ 165,347 Marketable securities 8,946 — — 8,946 Accounts Receivable 23,000 — (8,400) 14,600 Prepaid expenses 11,431 (2,040) — 9,391 Inventory 20,969 (3,205) 602 18,366 Other current assets 17,383 3,538 20,921 Total current assets 247,076 (1,707) (7,798) 237,571 Property, plant and equipment, net 9,972 63,398 (280) 73,090 Goodwill 5,646 — — 5,646 Intangible assets, net 5,368 — — 5,368 Operating lease right-of-use assets 294,717 (87,796) 206,921 Restricted cash and other non-current assets 50,829 3,665 — 54,494 Total assets $ 613,608 $ (22,440) $ (8,078) $ 583,090 Liabilities and Stockholders’ Equity Current Liabilities: Accounts payable $ 19,852 $ (3,042) $ 316 $ 17,126 Deferred revenue 9,653 — (8,400) 1,253 Accrued expenses and other current liabilities 57,768 572 — 58,340 Operating lease liability, current portion 71,684 (46,160) — 25,524 Financing lease liability, current portion — 85,208 — 85,208 Total current liabilities 158,957 36,578 (8,084) 187,451 Operating lease liability, net of current portion 232,023 (39,456) — 192,567 Financing lease liability, net of current portion — 50,146 — 50,146 Other non-current liabilities 92 — — 92 Total liabilities 391,072 47,268 (8,084) 430,256 Commitments and contingencies (Note 12) Stockholders’ Equity: Preferred stock, $0.01 par value, 5,000 shares authorized; 0 shares issued and outstanding at September 30, 2023 $ — $ — $ — $ — Common stock, $0.01 par value, 250,000 shares authorized; 107,022 shares issued and outstanding at September 30, 2023 1,071 — — 1,071 Additional paid-in capital 4,333,594 — (98) 4,333,496 Accumulated other comprehensive loss (2,227) — — (2,227) Accumulated deficit (4,109,902) (69,708) 104 (4,179,506) Total stockholders’ equity 222,536 (69,708) 6 152,834 Total liabilities and stockholders’ equity $ 613,608 $ (22,440) $ (8,078) $ 583,090 As of March 31, 2022 (in thousands) As Previously Reported Adjustments to Leases Other Adjustments As Restated Assets Current assets: Cash and cash equivalents $ 106,260 $ — $ — $ 106,260 Marketable securities 105,328 — — 105,328 Prepaid expenses 31,798 (1,549) — 30,249 Receivables and other current assets 11,531 198 — 11,729 Total current assets 254,917 (1,351) — 253,566 Marketable securities 55,049 — — 55,049 Property, plant and equipment, net 11,234 (599) (459) 10,176 Goodwill 5,646 — — 5,646 Operating lease right-of-use assets 111,897 (61,082) — 50,815 Restricted cash and other non-current assets 52,328 3,665 — 55,993 Total assets $ 491,071 $ (59,367) $ (459) $ 431,245 Liabilities and Stockholders’ Equity Current Liabilities: Accounts payable $ 28,350 $ (4,937) $ — $ 23,413 Accrued expenses and other current liabilities 89,032 (15,597) 1,999 75,434 Operating lease liability, current portion 25,510 (9,262) — 16,248 Financing lease liability, current portion — 55,995 — 55,995 Total current liabilities 142,892 26,199 1,999 171,090 Operating lease liability, net of current portion 84,828 (46,407) — 38,421 Financing lease liability, net of current portion — 41,315 — 41,315 Other non-current liabilities 92 — — 92 Total liabilities 227,812 21,107 1,999 250,918 Commitments and contingencies (Note 12) Stockholders’ Equity: Preferred stock, $0.01 par value, 5,000 shares authorized; 0 shares issued and outstanding at March 31, 2022 $ — $ — $ — $ — Common stock, $0.01 par value, 125,000 shares authorized; 71,438 shares issued and outstanding at March 31, 2022 714 — — 714 Additional paid-in capital 4,109,081 — (1,384) 4,107,697 Accumulated other comprehensive loss (4,459) — — (4,459) Accumulated deficit (3,842,077) (80,474) (1,074) (3,923,625) Total stockholders’ equity 263,259 (80,474) (2,458) 180,327 Total liabilities and stockholders’ equity $ 491,071 $ (59,367) $ (459) $ 431,245 As of June 30, 2022 (in thousands) As Previously Reported Adjustments to Leases Other Adjustments As Restated Assets Current assets: Cash and cash equivalents $ 81,499 $ — $ — $ 81,499 Marketable securities 51,010 — — 51,010 Prepaid expenses 24,473 (667) — 23,806 Receivables and other current assets 10,476 2,997 — 13,473 Total current assets 167,458 2,330 — 169,788 Marketable securities 40,641 — — 40,641 Property, plant and equipment, net 14,566 (688) (406) 13,472 Goodwill 5,646 — — 5,646 Operating lease right-of-use assets 292,731 (54,005) — 238,726 Restricted cash and other non-current assets 52,550 3,665 — 56,215 Total assets $ 573,592 $ (48,698) $ (406) $ 524,488 Liabilities and Stockholders’ Equity Current Liabilities: Accounts payable $ 24,865 $ (2,846) $ — $ 22,019 Accrued expenses and other current liabilities 75,550 (12,189) 1,999 65,360 Operating lease liability, current portion 48,446 (22,583) — 25,863 Financing lease liability, current portion — 47,219 — 47,219 Total current liabilities 148,861 9,601 1,999 160,461 Operating lease liability, net of current portion 244,522 (27,634) — 216,888 Financing lease liability, net of current portion — 36,550 — 36,550 Other non-current liabilities 93 — — 93 Total liabilities 393,476 18,517 1,999 413,992 Commitments and contingencies (Note 12) Stockholders’ Equity: Preferred stock, $0.01 par value, 5,000 shares authorized; 0 shares issued and outstanding at June 30, 2022 $ — $ — $ — $ — Common stock, $0.01 par value, 125,000 shares authorized; 73,551 shares issued and outstanding at June 30, 2022 735 — — 735 Additional paid-in capital 4,126,012 — (1,854) 4,124,158 Accumulated other comprehensive loss (4,416) — — (4,416) Accumulated deficit (3,942,215) (67,215) (551) (4,009,981) Total stockholders’ equity 180,116 (67,215) (2,405) 110,496 Total liabilities and stockholders’ equity $ 573,592 $ (48,698) $ (406) $ 524,488 As of September 30, 2022 (in thousands) As Previously Reported Adjustments to Leases Other Adjustments As Restated Assets Current assets: Cash and cash equivalents $ 66,478 $ — $ — $ 66,478 Marketable securities 73,155 — — 73,155 Prepaid expenses 8,270 55 — 8,325 Receivables and other current assets 12,535 2,425 — 14,960 Total current assets 160,438 2,480 — 162,918 Marketable securities 1,407 — — 1,407 Property, plant and equipment, net 11,535 (777) (358) 10,400 Goodwill 5,646 — — 5,646 Intangible assets, net — — 4,972 4,972 Operating lease right-of-use assets 288,684 (56,750) — 231,934 Restricted cash and other non-current assets 52,388 3,665 — 56,053 Total assets $ 520,098 $ (51,382) $ 4,614 $ 473,330 Liabilities and Stockholders’ Equity Current Liabilities: Accounts payable $ 18,622 $ (2,898) $ — $ 15,724 Accrued expenses and other current liabilities 64,314 (13,432) 1,998 52,880 Operating lease liability, current portion 43,791 (20,322) — 23,469 Financing lease liability, current portion — 41,264 — 41,264 Total current liabilities 126,727 4,612 1,998 133,337 Operating lease liability, net of current portion 234,422 (24,069) — 210,353 Financing lease liability, net of current portion — 31,036 — 31,036 Other non-current liabilities 92 — — 92 Total liabilities 361,241 11,579 1,998 374,818 Commitments and contingencies (Note 12) Stockholders’ Equity: Preferred stock, $0.01 par value, 5,000 shares authorized; 0 shares issued and outstanding at September 30, 2022 $ — $ — $ — $ — Common stock, $0.01 par value, 125,000 shares authorized; 82,880 shares issued and outstanding at September 30, 2022 829 — — 829 Additional paid-in capital 4,181,393 — (2,043) 4,179,350 Accumulated other comprehensive loss (4,630) — — (4,630) Accumulated deficit (4,018,735) (62,961) 4,659 (4,077,037) Total stockholders’ equity 158,857 (62,961) 2,616 98,512 Total liabilities and stockholders’ equity $ 520,098 $ (51,382) $ 4,614 $ 473,330 Condensed Consolidated Statements of Operations and Comprehensive Loss The following unaudited condensed consolidated statements of operations and comprehensive loss tables present the impacts of the restatement adjustments for the three months ended March 31, 2023 and 2022, the three and six months ended June 30, 2023 and 2022, and the three and nine months ended September 30, 2023 and 2022. The year ended December 31, 2023 was not subject to restatement. Three Months ended March 31, 2023 (in thousands, except per share amounts) As Previously Reported Adjustments to Leases Other Adjustments As Restated Revenue Product revenue $ 2,296 $ — $ — $ 2,296 Other revenue 85 — — 85 Total revenues 2,381 — — 2,381 Cost of product revenue 3,376 2,136 — 5,512 Gross margin (995) (2,136) — (3,131) Operating expenses: Selling, general and administrative 37,354 113 — 37,467 Research and development 46,144 (4,516) (41) 41,587 Total operating expenses 83,498 (4,403) (41) 79,054 Gain from sale of priority review voucher, net 92,930 — — 92,930 Income (loss) from operations 8,437 2,267 41 10,745 Interest income 2,828 — — 2,828 Interest expense (3) (4,267) — (4,270) Other income, net 9,978 (351) — 9,627 Income (loss) before income taxes 21,240 (2,351) 41 18,930 Income tax (expense) benefit — — — — Net income (loss) 21,240 (2,351) 41 18,930 Net income (loss) per share - basic (1) $ 0.21 $ (0.02) $ — $ 0.18 Net income (loss) per share - diluted (1) $ 0.21 $ (0.02) $ — $ 0.18 Weighted-average number of common shares used in computing net income (loss) per share - basic: 102,920 — — 102,920 Weighted-average number of common shares used in computing net income (loss) per share - diluted: 103,303 — — 103,303 Other comprehensive income (loss): Other comprehensive income (loss), net of tax (benefit) expense of $0.0 million for the three months ended March 31, 2023 984 — — 984 Total other comprehensive income (loss) 984 — — 984 Comprehensive income (loss) $ 22,224 $ (2,351) $ 41 $ 19,914 (1) Due to differences in rounding to the nearest cent per basic or diluted share, totals may not equal the sum of the line items. Six Months ended June 30, 2023 (in thousands, except per share amounts) As Previously Reported Adjustments to Leases Other Adjustments As Restated Revenue Product revenue $ 9,133 $ — $ — $ 9,133 Other revenue 138 — — 138 Total revenues 9,271 — — 9,271 Cost of product revenue 12,940 (731) — 12,209 Gross margin (3,669) 731 — (2,938) Operating expenses: Selling, general and administrative 77,703 226 — 77,929 Research and development 88,418 (14,705) (678) 73,035 Total operating expenses 166,121 (14,479) (678) 150,964 Gain from sale of priority review voucher, net 92,930 — — 92,930 Income (loss) from operations (76,860) 15,210 678 (60,972) Interest income 5,507 — — 5,507 Interest expense (3) (8,017) — (8,020) Other income, net 19,608 (62) — 19,546 Income (loss) before income taxes (51,748) 7,131 678 (43,939) Income tax (expense) benefit 80 — 80 Net income (loss) (51,668) 7,131 678 (43,859) Net income (loss) per share - basic $ (0.49) $ 0.07 $ 0.01 $ (0.41) Net income (loss) per share - diluted $ (0.49) $ 0.07 $ 0.01 $ (0.41) Weighted-average number of common shares used in computing net income (loss) per share - basic: 105,819 — — 105,819 Weighted-average number of common shares used in computing net income (loss) per share - diluted: 105,819 — — 105,819 Other comprehensive income (loss): Other comprehensive income (loss), net of tax (benefit) expense of $0.0 million for the six months ended June 30, 2023 1,706 — — 1,706 Total other comprehensive income (loss) 1,706 — — 1,706 Comprehensive income (loss) $ (49,962) $ 7,131 $ 678 $ (42,153) Three Months ended June 30, 2023 (in thousands, except per share amounts) As Previously Reported Adjustments to Leases Other Adjustments As Restated Revenue Product revenue $ 6,837 $ — $ — $ 6,837 Other revenue 53 — — 53 Total revenues 6,890 — — 6,890 Cost of product revenue 9,564 (2,867) — 6,697 Gross margin (2,674) 2,867 — 193 Operating expenses: — Selling, general and administrative 40,349 113 — 40,462 Research and development 42,274 (10,189) (637) 31,448 Total operating expenses 82,623 (10,076) (637) 71,910 Income (loss) from operations (85,297) 12,943 637 (71,717) Interest income 2,679 — — 2,679 Interest expense — (3,750) — (3,750) Other income, net 9,630 289 — 9,919 Income (loss) before income taxes (72,988) 9,482 637 (62,869) Income tax (expense) benefit 80 — — 80 Net income (loss) (72,908) 9,482 637 (62,789) Net income (loss) per share - basic (1) $ (0.67) $ 0.09 $ 0.01 $ (0.58) Net income (loss) per share - diluted (1) $ (0.67) $ 0.09 $ 0.01 $ (0.58) Weighted-average number of common shares used in computing net income (loss) per share - basic: 108,685 — — 108,685 Weighted-average number of common shares used in computing net income (loss) per share - diluted: 108,685 — — 108,685 Other comprehensive income (loss): Other comprehensive income (loss), net of tax (benefit) expense of $0.0 million for the three months ended June 30, 2023 722 — — 722 Total other comprehensive income (loss) 722 — — 722 Comprehensive income (loss) $ (72,186) $ 9,482 $ 637 $ (62,067) (1) Due to differences in rounding to the nearest cent per basic or diluted share, totals may not equal the sum of the line items. Nine Months ended September 30, 2023 (in thousands, except per share amounts) As Previously Reported Adjustments to Leases Other Adjustments As Restated Revenue Product revenue $ 21,414 $ — $ — $ 21,414 Other revenue 249 — — 249 Total revenues 21,663 — — 21,663 Cost of product revenue 23,895 (2,560) — 21,335 Gross margin (2,232) 2,560 — 328 Operating expenses: — Selling, general and administrative 118,406 294 — 118,700 Research and development 133,881 52 (2,397) 131,536 Total operating expenses 252,287 346 (2,397) 250,236 Gain from sale of priority review voucher, net 92,930 — — 92,930 Income (loss) from operations (161,589) 2,214 2,397 (156,978) Interest income 7,961 — — 7,961 Interest expense (3) (12,328) — (12,331) Other income (expense), net 30,152 106 (81) 30,177 Income (loss) before income taxes (123,479) (10,008) 2,316 (131,171) Income tax (expense) benefit 80 — — 80 Net income (loss) (123,399) (10,008) 2,316 (131,091) Net income (loss) per share - basic (1) $ (1.15) $ (0.09) $ 0.02 $ (1.23) Net income (loss) per share - diluted (1) $ (1.15) $ (0.09) $ 0.02 $ (1.23) Weighted-average number of common shares used in computing net income (loss) per share - basic: 106,924 — — 106,924 Weighted-average number of common shares used in computing net income (loss) per share - diluted: 106,924 — — 106,924 Other comprehensive income (loss): Other comprehensive income (loss), net of tax (benefit) expense of $0.0 million for the nine months ended September 30, 2023 1,843 — — 1,843 Total other comprehensive income (loss) 1,843 — — 1,843 Comprehensive income (loss) $ (121,556) $ (10,008) $ 2,316 $ (129,248) (1) Due to differences in rounding to the nearest cent per basic or diluted share, totals may not equal the sum of the line items. Three Months ended September 30, 2023 (in thousands, except per share amounts) As Previously Reported Adjustments to Leases Other Adjustments As Restated Revenue Product revenue $ 12,281 $ — $ — $ 12,281 Other revenue 111 — — 111 Total revenues 12,392 — — 12,392 Cost of product revenue 10,955 (1,829) — 9,126 Gross margin 1,437 1,829 — 3,266 Operating expenses: Selling, general and administrative 40,703 68 — 40,771 Research and development 45,463 14,757 (1,719) 58,501 Total operating expenses 86,166 14,825 (1,719) 99,272 Income (loss) from operations (84,729) (12,996) 1,719 (96,006) Interest income 2,454 — — 2,454 Interest expense — (4,311) — (4,311) Other income (expense), net 10,544 168 (81) 10,631 Income (loss) before income taxes (71,731) (17,139) 1,638 (87,232) Income tax (expense) benefit — — — — Net income (loss) (71,731) (17,139) 1,638 (87,232) Net income (loss) per share - basic $ (0.66) $ (0.16) $ 0.02 $ (0.80) Net income (loss) per share - diluted $ (0.66) $ (0.16) $ 0.02 $ (0.80) Weighted-average number of common shares used in computing net income (loss) per share - basic: 109,098 — — 109,098 Weighted-average number of common shares used in computing net income (loss) per share - diluted: 109,098 — — 109,098 Other comprehensive income (loss): Other comprehensive income (loss), net of tax (benefit) expense of $0.0 million for the three months ended September 30, 2023 137 — — 137 Total other comprehensive income (loss) 137 — — 137 Comprehensive income (loss) $ (71,594) $ (17,139) $ 1,638 $ (87,095) Three Months ended March 31, 2022 (in thousands, except per share amounts) As Previously Reported Adjustments to Leases Other Adjustments As Restated Revenue: Product revenue $ 1,408 $ — $ — $ 1,408 Other revenue 537 — — 537 Total revenues 1,945 — — 1,945 Cost of product revenue 8,310 — — 8,310 Gross margin (6,365) — — (6,365) Operating expenses: Research and development 77,875 (15,511) (930) 61,434 Selling, general and administrative 36,106 (147) (510) 35,449 Total operating expenses 113,981 (15,658) (1,440) 96,883 Income (loss) from operations (120,346) 15,658 1,440 (103,248) Interest income 106 — — 106 Interest expense — (1,028) — (1,028) Other income (expense), net (1,912) 530 — (1,382) Income (loss) before income taxes (122,152) 15,160 1,440 (105,552) Income tax (expense) benefit — — — — Net income (loss) (122,152) 15,160 1,440 (105,552) Net income (loss) per share - basic $ (1.66) $ 0.21 $ 0.02 $ (1.43) Net income (loss) per share - diluted $ (1.66) $ 0.21 $ 0.02 $ (1.43) Weighted-average number of common shares used in computing net income (loss) per share - basic: 73,688 — — 73,688 Weighted-average number of common shares used in computing net income (loss) per share - diluted: 73,688 — — 73,688 Other comprehensive income (loss): Other comprehensive income (loss), net of tax (benefit) expense of $0.0 million for the three months ended March 31, 2022 (1,548) — — (1,548) Total other comprehensive income (loss) (1,548) — — (1,548) Comprehensive income (loss) $ (123,700) $ 15,160 $ 1,440 $ (107,100) Six Months ended June 30, 2022 (in thousands, except per share amounts) As Previously Reported Adjustments to Leases Other Adjustments As Restated Revenue: Product revenue $ 2,739 $ — $ — $ 2,739 Other revenue 725 — — 725 Total revenues 3,464 — — 3,464 Cost of product revenue 10,055 — — 10,055 Gross margin (6,591) — — (6,591) Operating expenses: Research and development 141,716 (27,866) (1,192) 112,658 Selling, general and administrative 72,800 (461) (771) 71,568 Restructuring expenses 6,639 — — 6,639 Total operating expenses 221,155 (28,327) (1,963) 190,865 Income (loss) from operations (227,746) 28,327 1,963 (197,456) Interest income 280 — — 280 Interest expense — (1,950) — (1,950) Other income, net 5,176 2,042 — 7,218 Income (loss) before income taxes (222,290) 28,419 1,963 (191,908) Income tax (expense) benefit — — — — Net income (loss) (222,290) 28,419 1,963 (191,908) Net income (loss) per share - basic $ (3.02) $ 0.39 $ 0.03 $ (2.60) Net income (loss) per share - diluted $ (3.02) $ 0.39 $ 0.03 $ (2.60) Weighted-average number of common shares used in computing net income (loss) per share - basic: 73,727 — — 73,727 Weighted-average number of common shares used in computing net income (loss) per share - diluted: 73,727 — — 73,727 Other comprehensive income (loss): Other comprehensive income (loss), net of tax (benefit) expense of $0.0 million for the six months ended June 30, 2022 (1,505) — — (1,505) Total other comprehensive income (loss) (1,505) — — (1,505) Comprehensive income (loss) $ (223,795) $ 28,419 $ 1,963 $ (193,413) Three Months ended June 30, 2022 (in thousands, except per share amounts) As Previously Reported Adjustments to Leases Other Adjustments As Restated Revenue: Product revenue $ 1,331 $ — $ — $ 1,331 Other revenue 188 — — 188 Total revenues 1,519 — — 1,519 Cost of product revenue 1,745 — — 1,745 Gross margin (226) — — (226) Operating expenses: Research and development 63,841 (12,355) (262) 51,224 Selling, general and administrative 36,694 (314) (261) 36,119 Restructuring expenses 6,639 — — 6,639 Total operating expenses 107,174 (12,669) (523) 93,982 Income (loss) from operations (107,400) 12,669 523 (94,208) Interest income 174 — — 174 Interest expense — (922) — (922) Other income, net 7,088 1,512 — 8,600 Income (loss) before income taxes (100,138) 13,259 523 (86,356) Income tax (expense) benefit — — — — Net income (loss) (100,138) 13,259 523 (86,356) Net income (loss) per share - basic $ (1.36) $ 0.18 $ 0.01 $ (1.17) Net income (loss) per share - diluted $ (1.36) $ 0.18 $ 0.01 $ (1.17) Weighted-average number of common shares used in computing net income (loss) per share - basic: 73,767 — — 73,767 Weighted-average number of common shares used in computing net income (loss) per share - diluted: 73,767 — — 73,767 Other comprehensive income (loss): Other comprehensive income (loss), net of tax (benefit) expense of $0.0 million for the three months ended June 30, 2022 43 — — 43 Total other comprehensive income (loss) 43 — — 43 Comprehensive income (loss) $ (100,095) $ 13,259 $ 523 $ (86,313) Nine Months ended September 30, 2022 (in thousands, except per share amounts) As Previously Reported Adjustments to Leases Other Adjustments As Restated Revenue: Product revenue $ 2,739 $ — $ — $ 2,739 Other revenue 795 — — 795 Total revenues 3,534 — — 3,534 Cost of product revenue 10,056 — — 10,056 Gross margin (6,522) — — (6,522) Operating expenses: Research and development 194,864 (30,789) (6,406) 157,669 Selling, general and administrative 106,201 (188) (767) 105,246 Restructuring expenses 4,940 — — 4,940 Total operating expenses 306,005 (30,977) (7,173) 267,855 Income (loss) from operations (312,527) 30,977 7,173 (274,377) Interest income 663 — — 663 Interest expense — (3,502) — (3,502) Other income, net 13,061 5,198 — 18,259 Income (loss) before income taxes (298,803) 32,673 7,173 (258,957) Income tax (expense) benefit (7) — — (7) Net income (loss) (298,810) 32,673 7,173 (258,964) Net income (loss) per share - basic $ (3.91) $ 0.43 $ 0.09 $ (3.39) Net income (loss) per share - diluted $ (3.91) $ 0.43 $ 0.09 $ (3.39) Weighted-average number of common shares used in computing net income (loss) per share - basic: 76,361 — — 76,361 Weighted-average number of common shares used in computing net income (loss) per share - diluted: 76,361 — — 76,361 Other comprehensive income (loss): Other comprehensive income (loss), net of tax (benefit) expense of $0.0 million for the nine months ended September 30, 2022 (1,719) — — (1,719) Total other comprehensive income (loss) (1,719) — — (1,719) Comprehensive income (loss) $ (300,529) $ 32,673 $ 7,173 $ (260,683) Three Months ended September 30, 2022 (in thousands, except per share amounts) As Previously Reported Adjustments to Leases Other Adjustments As Restated Revenue: Product revenue $ — $ — $ — $ — Other revenue 71 — — 71 Total revenues 71 — — 71 Cost of product revenue — — — — Gross margin 71 — — 71 Operating expenses: Research and development 53,149 (2,923) (5,214) 45,012 Selling, general and administrative 33,402 273 4 33,679 Restructuring expenses (1,699) — — (1,699) Total operating expenses 84,852 (2,650) (5,210) 76,992 Income (loss) from operations (84,781) 2,650 5,210 (76,921) Interest income 383 — — 383 Interest expense — (1,552) — (1,552) Other income, net 7,885 3,156 — 11,041 Income (loss) before income taxes (76,513) 4,254 5,210 (67,049) Income tax (expense) benefit (7) — — (7) Net income (loss) (76,520) 4,254 5,210 (67,056) Net income (loss) per share - basic (1) $ (0.94) $ 0.05 $ 0.06 $ (0.82) Net income (loss) per share - diluted (1) $ (0.94) $ 0.05 $ 0.06 $ (0.82) Weighted-average number of common shares used in computing net income (loss) per share - basic: 81,543 — — 81,543 Weighted-average number of common shares used in computing net income (loss) per share - diluted: 81,543 — — 81,543 Other comprehensive income (loss): Other comprehensive income (loss), net of tax (benefit) expense of $0.0 million for the three months ended September 30, 2022 (214) — — (214) Total other comprehensive income (loss) (214) — — (214) Comprehensive income (loss) $ (76,734) $ 4,254 $ 5,210 $ (67,270) (1) Due to differences in rounding to the nearest cent per basic or diluted share, totals may not equal the sum of the line items. Condensed Consolidated Statements of Stockholders' Equity The following unaudited condensed consolidated statements of stockholders' equity tables present the impacts of the restatement adjustments for the three months ended March 31, 2023 and 2022, the three months ended June 30, 2023 and 2022, and the three months ended September 30, 2023 and 2022. The year ended December 31, 2023, was not subject to restatement. Common stock Additional Accumulated Accumulated Total (in thousands) Shares Amount As Previously Reported Balances at December 31, 2022 82,923 $ 830 $ 4,186,086 $ (4,070) $ (3,986,503) $ 196,343 Vesting of restricted stock 382 3 (198) — — (195) Exercise of stock options 3 — 7 — — 7 Purchase of shares under ESPP 62 1 226 — — 227 Issuance of common stock 23,000 230 130,061 — — 130,291 Stock-based compensation expense — — 5,843 — — 5,843 Other comprehensive income (loss) — — — 984 — 984 Net income (loss) — — — — 21,240 21,240 Balances at March 31, 2023 106,370 $ 1,064 $ 4,322,025 $ (3,086) $ (3,965,263) $ 354,740 Adjustments to Leases Balances at December 31, 2022 — — — — (59,700) (59,700) Vesting of restricted stock — — — — — — Exercise of stock options — — — — — — Purchase of shares under ESPP — — — — — — Issuance of common stock — — — — — — Stock-based compensation expense — — — — — — Other comprehensive income (loss) — — — — — — Net income (loss) — — — — (2,351) (2,351) Balances at March 31, 2023 — $ — $ — $ — $ (62,051) $ (62,051) Other Adjustments Balances at December 31, 2022 — — (98) — (2,212) (2,310) Vesting of restricted stock — — — — — — Exercise of stock options — — — — — — Purchase of shares under ESPP — — — — — — Issuance of common stock — — — — — — Stock-based compensation expense — — — — — — Other comprehensive income (loss) — — — — — — Net income (loss) — — — — 41 41 Balances at March 31, 2023 — $ — $ (98) $ — $ (2,171) $ (2,269) As Restated Balances at December 31, 2022 82,923 830 4,185,988 (4,070) (4,048,415) 134,333 Vesting of restricted stock 382 3 (198) — — (195) Exercise of stock options 3 — 7 — — 7 Purchase of shares under ESPP 62 1 226 — — 227 Issuance of common stock 23,000 230 130,061 — — 130,291 Stock-based compensation expense — — 5,843 — — 5,843 Other comprehensive income (loss) — — — 984 — 984 Net income (loss) — — — — 18,930 18,930 Balances at March 31, 2023 106,370 $ 1,064 $ 4,321,927 $ (3,086) $ (4,029,485) $ 290,420 Common stock Additional Accumulated Accumulated Total (in thousands) Shares Amount As previously reported Balances at March 31, 2023 106,370 $ 1,064 $ 4,322,025 $ (3,086) $ (3,965,263) $ 354,740 Vesting of restricted stock 65 1 (1) — — — Exercise of stock options 19 — 77 — — 77 Stock-based compensation expense — — 6,388 — — 6,388 Other comprehensive income (loss) — — — 722 — 722 Net income (loss) — — — — (72,908) (72,908) Balances at June 30, 2023 106,454 $ 1,065 $ 4,328,489 $ (2,364) $ (4,038,171) $ 289,019 Adjustments to Leases Balances at March 31, 2023 — — — — (62,051) (62,051) Vesting of restricted stock — — — — — — Exercise o

Subsequent events

Subsequent events	12 Months Ended
	Dec. 31, 2023
Subsequent Events [Abstract]
Subsequent events	Subsequent events On March 15, 2024, the Company entered into a five-year term loan facility agreement with Hercules Capital, Inc. ("Hercules") to secure debt financing for up to $175 million, available in four tranches. The first tranche in an amount equal to $75 million was drawn at the time of closing (the "Initial Loan"). The Company may draw upon two additional tranches of $25 million each, subject to satisfaction of certain conditions, including achievement of commercial milestones. The facility also provides a fourth tranche of $50 million, available at the sole discretion of Hercules, until December 15, 2026. The 2024 Term Loan is collateralized by substantially all the Company’s assets. The Loan and Security Agreement ("LSA") requires the Company to comply with customary affirmative and negative covenants, including, among other things, a requirement to deliver annual financial statements within 90 days of each fiscal year and quarterly financial statements within 45 days of each fiscal quarter, a minimum cash coverage requirement, and a minimum net product revenue requirement. A failure to comply with these covenants, or failure to obtain a waiver for any non-compliance, would result in an event of default under the LSA and would allow Hercules to accelerate repayment of the debt, which could materially and adversely affect the business, results of operations and financial condition of the Company. On April 30, 2024, July 9, 2024, August 13, 2024 and August 29, 2024, the Company and Hercules entered into amendments to the LSA providing for revised monthly financial reporting metrics for each month through September 30, 2024 and extension of the deadlines by which the Company must provide certain annual and quarterly financial statements. The Company was in compliance with the minimum cash coverage covenant as of March 31, 2024, however, the Company’s current business plan anticipates noncompliance with the minimum cash requirements within the twelve months of the issuance of these financial statements. On August 13, 2024, the Company and Hercules entered into a third amendment to the LSA (the “Third Amendment”), pursuant to which the parties agreed to, among other things, revised terms for the availability of the second and third tranches of funding under the LSA. In accordance with the Third Amendment, the Company may draw the second tranche of $25.0 million during the period commencing on the date the Company has (x) received at least $75.0 million in gross cash proceeds from qualified financing transactions by December 20, 2024 and (y) completed patient starts (cell collections) for at least 50 LYFGENIA patients by March 31, 2025 or 70 LYFGENIA patients by June 30, 2025 (collectively, the “Tranche 2 Milestone”) and ending on the earlier of (i) the date that is 30 days immediately following achievement of the Tranche 2 Milestone and (ii) July 31, 2025. The Company may draw the third tranche of $25.0 million during the period commencing on the date the Company has (x) received at least $100.0 million in gross cash proceeds from qualified financing transactions by December 20, 2024 or at least $125.0 million by June 30, 2025 and (y) completed 70 drug product deliveries within a given six-month period ending no later than December 31, 2025, at least 40 of which are for LYFGENIA (collectively, the “Tranche 3 Milestone”) and ending on the earlier of (i) the date that is 30 days immediately following the date the Company achieves the Tranche 3 Milestone and (ii) December 31, 2025. Additionally, the Company and Hercules agreed to increase the minimum cash coverage requirement from 40% to 45% of the outstanding principal of the term loan.

Pay vs Performance Disclosure

Pay vs Performance Disclosure - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Pay vs Performance Disclosure
Net loss	$ (211,913)	$ (230,342)

Insider Trading Arrangements

Insider Trading Arrangements	3 Months Ended
	Dec. 31, 2023
Trading Arrangements, by Individual
Rule 10b5-1 Arrangement Adopted	false
Non-Rule 10b5-1 Arrangement Adopted	false
Rule 10b5-1 Arrangement Terminated	false
Non-Rule 10b5-1 Arrangement Terminated	false

Summary of significant accoun_2

Summary of significant accounting policies and basis of presentation (Policies)	12 Months Ended
	Dec. 31, 2023
Accounting Policies [Abstract]
Basis of presentation	Basis of presentation The Company's consolidated financial statements have been prepared in accordance with accounting principles generally accepted in the United States (“GAAP”). The accompanying consolidated financial statements include the accounts of the Company and its wholly owned or controlled subsidiaries. All intercompany accounts and transactions have been eliminated. Any reference in these notes to applicable guidance is meant to refer to the authoritative United States GAAP as included in the Accounting Standard Codification (“ASC”) and the Accounting Standards Updates (“ASUs”) of the Financial Accounting Standards Board (“FASB”). Amounts reported are computed based on thousands, except percentages, per share amounts, or as otherwise noted. As a result, certain totals may not sum due to rounding.
Reclassification of Prior Year Presentation	Reclassification of Prior Year Presentation Certain prior year amounts have been reclassified to conform to the current year presentation. Specifically, interest expense has been reclassified from interest income to interest expense in the consolidated statement of operations and comprehensive loss. These reclassifications had no effect on the reported results of operations.
Principles of consolidation	Principles of consolidation
Use of estimates	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: the alternative future use of assets used in research and development activities, future undiscounted cash flows and subsequent fair value estimates used to assess potential and measure any impairment of long-lived assets, including goodwill and intangible assets, and the measurement of right-of-use assets and lease liabilities, gross-to-net revenue calculations, stock-based compensation expense, accrued expenses, income taxes, 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, and the assessment of the likelihood and magnitude of losses that may be sustained upon resolution of contingencies.
Foreign currency translation	Foreign currency translation The financial statements of the Company’s subsidiaries with functional currencies other than the U.S. dollar are translated into U.S. dollars using period-end exchange rates for assets and liabilities, historical exchange rates for stockholders’ equity and weighted average exchange rates for operating results. Translation gains and losses are included in other comprehensive income (loss) in stockholders’ equity. Foreign currency transaction gains and losses are included in other income, net in the results of operations.
Segment information	Segment information The Company operates in a single segment, focusing on researching, developing and commercializing potentially transformative gene therapies for severe genetic diseases. Consistent with its operational structure, its chief operating decision maker manages and allocates resources at a global, consolidated level. Therefore, results of the Company's operations are reported on a consolidated basis for purposes of segment reporting. All material long-lived assets of the Company reside in the United States.
Cash and cash equivalents	Cash and cash equivalents The Company considers all highly liquid investments purchased with original final maturities of 90 days or less from the date of purchase to be cash equivalents. Cash equivalents comprise marketable securities with maturities of less than 90 days when purchased. Cash equivalents are reported at fair value.
Marketable securities	Marketable securities The Company’s marketable securities are maintained by investment managers and consist of U.S. government agency securities and treasuries, equity securities, corporate bonds and commercial paper. Debt securities are carried at fair value with the unrealized gains and losses included in other comprehensive income (loss) as a component of stockholders’ equity until realized. Any premium arising at purchase is amortized to the earliest call date and any discount arising at purchase is accreted to maturity. Amortization and accretion of premiums and discounts are recorded in interest income, net. Equity securities with readily determinable fair values are also carried at fair value with unrealized gains and losses included in other income, net. Realized gains and losses on both debt and equity securities are determined using the specific identification method and are included in other income, net. The Company classifies equity securities with readily determinable fair values, which would be available for use in its current operations, as current assets even though the Company may not dispose of such marketable securities within the next 12 months. Equity securities are included in the balance of marketable securities on the Company's consolidated balance sheets. The Company classifies marketable securities with a remaining maturity when purchased of greater than three months as available-for-sale. Marketable securities with a remaining maturity date greater than one year are classified as non-current assets. Effective January 1, 2020, the Company adopted ASU 2016-13, Financial Instruments - Credit Losses (Topic 326): Measurement of Credit Losses on Financial Statements (“ASU 2016-13” or “ASC 326”), using the effective date method. As the Company had never recorded any other-than-temporary-impairment adjustments to its available-for-sale debt securities prior to the effective date, no transition provisions are applicable to the Company. The Company assesses its available-for-sale debt securities under the available-for-sale debt security impairment model in ASC 326 as of each reporting date in order to determine if a portion of any decline in fair value below carrying value recognized on its available-for-sale debt securities is the result of a credit loss. The Company records credit losses in the consolidated statements of operations and comprehensive loss as credit loss expense within other income, net, which is limited to the difference between the fair value and the amortized cost of the security. To date, the Company has not recorded any credit losses on its available-for-sale debt securities. Accrued interest receivable related to the Company's available-for-sale debt securities is presented within receivables and other current assets on the Company's consolidated balance sheets. The Company has elected the practical expedient available to exclude accrued interest receivable from both the fair value and the amortized cost basis of available-for-sale debt securities for the purposes of identifying and measuring any impairment. The Company writes off accrued interest receivable once it has determined that the asset is not realizable. Any write-offs of accrued interest receivable are recorded by reversing interest income, recognizing credit loss expense, or a combination of both. To date, the Company has not written off any accrued interest receivables associated with its marketable securities.
Concentrations of counter-party and liquidity risk	Concentrations of counter-party and liquidity risk To reduce exposure to counter-party and liquidity risk, the Company maintains concentration limits across all of its overnight bank deposits. As of December 31, 2023, the Company’s restricted cash balances were held in bank deposits. The remaining balance of cash and cash equivalents are invested in money market funds, U.S. government agency securities and treasuries, and investment grade commercial paper in line with the company’s board approved investment policy. The Company has not experienced any credit losses on its deposits of cash and cash equivalents.
Fair value of financial instruments	Fair value of financial instruments The Company has certain financial assets and liabilities recorded at fair value which have been classified as Level 1, 2 or 3 within the fair value hierarchy as described in the accounting standards for fair value measurements: Level 1—Fair values are determined utilizing quoted prices (unadjusted) in active markets for identical assets or liabilities that the Company has the ability to access at the measurement date. Level 2—Fair values are determined utilizing quoted prices for identical or similar assets or liabilities in active markets or other market observable inputs such as interest rates, yield curves and foreign currency spot rates. Level 3—Prices or valuations that require inputs that are both significant to the fair value measurement and unobservable. To the extent that valuation is based on models or inputs that are less observable or unobservable in the market, the determination of fair value requires more judgment. Accordingly, the degree of judgment exercised by the Company in determining fair value is greatest for instruments categorized in Level 3. A financial instrument’s level within the fair value hierarchy is based on the lowest level of any input that is significant to the fair value measurement. Items measured at fair value on a recurring basis include marketable securities (see Note 5, Marketable securities, and Note 6, Fair value measurements ). The carrying amounts of accounts payable and accrued expenses approximate their fair values due to their short-term nature.
Goodwill	Goodwill Goodwill represents the excess of the purchase price over the fair value of the net assets acquired when accounted for using the acquisition method of accounting for business combinations. Goodwill is not amortized but is evaluated for impairment within the Company’s single reporting unit on an annual basis, during the fourth quarter, or more frequently if an event occurs or circumstances change that would more-likely-than-not reduce the fair value of the Company’s reporting unit below its carrying amount. The Company performs a one-step quantitative test and records the amount of goodwill impairment, if any, as the excess of a reporting unit's carrying amount over its fair value, not to exceed the total amount of goodwill allocated to the reporting unit. The Company has not recognized any impairment charges related to goodwill to date. A significant sustained decrease in the Company’s common stock, may in the future be a potential indicator that all or a portion of our goodwill is impaired and may require a quantitative impairment assessment of the Company’s goodwill at an interim date, which may result in an impairment charge in future periods. While management cannot predict if or when future goodwill impairments may occur, an impairment could have material adverse effects on the Company’s financial condition, operating income, net assets, and/or the Company’s cost of, or access to, capital.
Intangible assets, net	Intangible assets, net
Property, plant and equipment	Property, plant and equipment Property, plant and equipment is stated at cost. Maintenance and repairs that do not improve or extend the lives of the respective assets are expensed to operations as incurred. Depreciation and amortization is calculated using the straight-line method over the estimated useful lives of the assets, which are as follows: Asset Estimated useful life Building 40 years Computer equipment and software 3 years Furniture and fixtures 5 years Laboratory equipment 3-5 years Finance lease right-of-use asset Shorter of the useful life or remaining lease term Leasehold improvements Shorter of the useful life or remaining lease term
Impairment of long-lived assets	Impairment of long-lived assets The Company reviews long-lived assets when events or changes in circumstances indicate the carrying value of the assets may not be recoverable. Recoverability is measured by comparison of the book values of the assets to future net undiscounted cash flows that the assets are expected to generate. If such assets are considered to be impaired, the impairment to be recognized is measured by the amount by which the book value of the assets exceed their fair value, which is measured based on the projected discounted future net cash flows arising from the assets.
Leases	Leases At the inception of an arrangement, the Company determines whether the arrangement is or contains a lease and its classification based on the unique facts and circumstances present in the arrangement. Leases with a term greater than one year are recognized on the balance sheet as right-of-use assets and current and non-current lease liabilities, as applicable. Right-of-use assets associated with finance leases used in the performance of research and development activities without alternative future use at lease commencement or at lease modification are immediately expensed to research and development expense pursuant to the guidance under ASC 730, Research and Development Costs. Lease liabilities and their corresponding right-of-use assets are initially recorded based on the present value of lease payments over the expected remaining lease term. Certain adjustments to the right-of-use asset may be required for items such as incentives received. The interest rate implicit in lease contracts is typically not readily determinable. As a result, the Company utilizes its incremental borrowing rate to discount lease payments, which reflects the fixed rate at which the Company could borrow on a collateralized basis the amount of the lease payments in the same currency, for a similar term, in a similar economic environment. To estimate its incremental borrowing rate, a credit rating applicable to the Company is estimated using a synthetic credit rating analysis since the Company does not currently have a rating agency-based credit rating. Subsequent to the initial measurement, the Company will continue to account for: • the lease liability at the net present value using the incremental borrowing rate that was in effect as of the lease commencement, lease modification, or transition date, and; • the finance lease right-of-use asset and operating lease expense on a straight line basis. The Company has elected not to recognize leases with an original term of one year or less on the balance sheet. The Company typically only includes an initial lease term in its assessment of a lease arrangement. Options to renew a lease are not included in the Company’s assessment unless there is reasonable certainty that the Company will renew. Assumptions made by the Company at the commencement date are re-evaluated upon occurrence of certain events, including a lease modification. A lease modification results in a separate contract when the modification changes the scope of or consideration for a lease or non-lease component under the agreement, such as when the lessor grants the lessee an additional right-of-use not included in the original lease and when lease payments increase commensurate with the standalone price for the additional right-of-use. When a lease modification results in a separate contract, it is accounted for in the same manner as a new lease. In accordance with ASC 842, components of a lease should be split into three categories: lease components, non-lease components, and non-components. The fixed and in-substance fixed contract consideration (including any consideration related to non-components) must be allocated based on the respective relative fair values to the lease components and non-lease components. Entities may elect not to separate lease and non-lease components. Rather, entities would account for each lease component and related non-lease component together as a single lease component. The Company has elected to account for lease and non- lease components together as a single lease component for real-estate leases and embedded CMO and CTO agreements and to allocate all the contract consideration to the lease component only, or to individual lease components on a relative standalone selling price basis when the lease terms associated with the individual lease components are not otherwise co-terminus. Lease modifications associated with embedded leases in contract manufacturing and testing arrangements arise with frequency based on the complexity of the gene therapy manufacturing processes and the related services provided by contract manufacturing and testing organizations, which are combined with lease components. The Company applies judgment in determining whether the contractual terms for the delivery of services represent a change in the scope or consideration of the arrangements, which are accounted for as lease modifications, or represent variable lease payments, which are recognized as incurred. ASC 842 allows for the use of judgment in determining whether the assumed lease term is for a major part of the remaining economic life of the underlying asset and whether the present value of lease payments represents substantially all of the fair value of the underlying asset. The Company applies the guidance in ASC 842-10-55-2 to assist in determining lease classification across its portfolio of leases.
Inventory	Inventory Inventories are stated at the lower of cost or net realizable value under the first-expired, first-out ("FEFO") methodology. Given human gene therapy products are a new and novel category of therapeutics and future economic benefit is not probable until regulatory approval for the product has been obtained, the Company has only considered inventory for capitalization upon regulatory approval. Manufacturing costs incurred prior to regulatory approval for pre-launch inventory that did not qualify for capitalization and clinical manufacturing costs are charged to research and development expense in the Company’s consolidated statements of operations and comprehensive loss as costs are incurred. Additionally, inventory that initially qualifies for capitalization but that may ultimately be used to produce clinical drug product is expensed as research and development expense when it has been designated for the manufacture of clinical drug product. Inventory consists of cell banks, plasmids, LVV, other materials and compounds sourced from third party suppliers and utilized in the manufacturing process, and drug product which has been produced for the treatment of specific patients, that are owned by the Company until infusion. Management periodically reviews inventories for excess or obsolescence, considering factors such as sales forecasts compared to quantities on-hand and firm purchase commitments as well as remaining shelf life of on-hand inventories. The Company writes down its inventory that is in excess, obsolete or otherwise unmarketable to its estimated net realizable value in the period in which the impairment is first identified. Any such adjustments are included as a component of cost of goods sold within cost of product revenue in the Company’s consolidated statements of operations and comprehensive loss.
Revenue recognition	Revenue recognition Under ASC Topic 606, Revenue from Contracts with Customers (“Topic 606”), an entity recognizes revenue when its customer obtains control of promised goods or services, in an amount that reflects the consideration that the entity expects to receive in exchange for those goods or services. To determine revenue recognition for arrangements that an entity determines are within the scope of Topic 606, the entity performs the following five steps: (i) identify the contract(s) with a customer; (ii) identify the performance obligations in the contract; (iii) determine the transaction price, including variable consideration, if any; (iv) allocate the transaction price to the performance obligations in the contract; and (v) recognize revenue when (or as) the entity satisfies a performance obligation. The Company only applies the five-step model to contracts when it is probable that the entity will collect the consideration to which it is entitled in exchange for the goods or services it transfers to the customer. Once a contract is determined to be within the scope of Topic 606, the Company assesses the goods or services promised within each contract and determines those that are performance obligations. Arrangements that include rights to additional goods or services that are exercisable at a customer’s discretion are generally considered options. The Company assesses if these options provide a material right to the customer and if so, they are considered performance obligations. The Company assesses whether each promised good or service is distinct to identify the performance obligations in the contract. This assessment involves subjective determinations and requires management to make judgments about the individual promised goods or services and whether such are separable from the other aspects of the contractual relationship. Promised goods and services are considered distinct provided that: (i) the customer can benefit from the good or service either on its own or together with other resources that are readily available to the customer (that is, the good or service is capable of being distinct) and (ii) the entity’s promise to transfer the good or service to the customer is separately identifiable from other promises in the contract (that is, the promise to transfer the good or service is distinct within the context of the contract). The transaction price is then determined and allocated to the identified performance obligations in proportion to their standalone selling prices (“SSP”) on a relative SSP basis. SSP is determined at contract inception and is not updated to reflect changes between contract inception and when the performance obligations are satisfied. If the consideration promised in a contract includes a variable amount, the Company estimates the amount of consideration to which it will be entitled in exchange for transferring the promised goods or services to a customer. The Company determines the amount of variable consideration by using the expected value method or the most likely amount method. The Company includes the unconstrained amount of estimated variable consideration in the transaction price. The amount included in the transaction price is constrained to the amount for which it is probable that a significant reversal of cumulative revenue recognized will not occur. At the end of each subsequent reporting period, the Company re-evaluates the estimated variable consideration included in the transaction price and any related constraint, and if necessary, adjusts its estimate of the overall transaction price. Any such adjustments are recorded on a cumulative catch-up basis in the adjustment period. In determining the transaction price, the Company adjusts consideration for the effects of the time value of money if the timing of payments provides the Company with a significant benefit of financing. The Company does not assess whether a contract has a significant financing component if the expectation at contract inception is such that the period between payment by the licensees and the transfer of the promised goods or services to the licensees will be one year or less. The Company assessed each of its revenue generating arrangements to determine whether a significant financing component exists and concluded that a significant financing component does not exist in any of its arrangements. The Company then recognizes as revenue the amount of the transaction price that is allocated to the respective performance obligation when (or as) each performance obligation is satisfied, either at a point in time or over time, and if over time recognition is based on the use of an output or input method. Product revenue In 2022, the Company received approval of ZYNTEGLO and SKYSONA from the FDA. In 2023, the Company received approval of LYFGENIA from the FDA. The amount of revenue recognized by the Company is equal to the amount of consideration that is expected to be received from the sale of product to its customers. The Company uses Specialty Distributors ("SD") and Specialty Pharmacies ("SP") to deliver product to the Qualified Treatment Centers ("QTC"). Revenue is only recognized when the performance obligation is satisfied. The Company recognizes revenue upon infusion to the patient. To determine whether a significant reversal will occur in future periods, the Company will assess both the likelihood and magnitude of any such potential reversal of revenue. Gross product revenue is reduced by outcomes-based rebates, other rebates and distributor fees. Rebates expense Rebates are based on contractual arrangements or statutory requirements and include amounts due to Medicaid agencies and third-party payers. These amounts may vary by product and payer. Rebates are estimated primarily based on product sales, including product mix and pricing, historical and estimated payer mix and discount rates, among other inputs, which require significant estimates and judgment. The Company assesses and updates estimates each reporting period to reflect actual claims and other current information. Rebates that are payable to Medicaid agencies and third-party payers are recorded in accrued expenses and other current liabilities on the Company's consolidated balance sheets. Distributor fees The Company pays distribution fees to SDs and SPs in connection with the sales of our product. These distributor fees are based on a contractually determined fixed percentage of sales. Other revenue In 2021, the Company entered into a grant agreement with the Bill and Melinda Gates Foundation. The Company recognizes grant revenue in accordance with ASC 958-605, Revenue Recognition Not-for-Profit Entities , when qualifying costs are incurred and barriers to restriction have been overcome. When grant funds are received after costs have been incurred, the Company records revenue and a corresponding grant receivable. Cash received from grants in advance of incurring qualifying costs is recorded as deferred revenue and recognized as revenue when qualifying costs are incurred. In 2023, the Company ceased further research work and is in the process of winding down such collaboration.
Factoring agreement	Factoring agreement In December 2023, the Company entered into a factoring agreement with a non-bank financial institution. The proceeds from the factoring agreement will be used to fund general working capital needs. The factoring agreement provides the Company access to up to $100.0 million on a revolving basis, measured by the outstanding balance of purchased accounts ("Purchased Accounts" as defined in the Invoice Purchase and Sales Agreement) sold on the purchase dates ("Purchase Dates" as defined in the Invoice Purchase and Sales Agreement) from time to time. The Company sells 100% of the invoice to Alterna Capital Solutions LLC, and the upfront purchase price for a Purchased Account is 90% of the invoice amount. The remaining 10% less applicable fees is payable only if and when Alterna Capital Solutions LLC receives full payment. The upfront payments are treated as a short-term liability, labeled as due to factor on our consolidated balance sheets. The short-term liability will be released upon infusion of the drug product. As of December 31, 2023, the balance in the due to factor account was $2.5 million. During December of 2023, the Company sold Purchased Accounts on the Purchase Dates to Alterna Capital Solutions LLC. The Purchased Assets are not available to our creditors to satisfy any of our obligations.
Selling, general and administrative expenses	Selling, general and administrative expenses Selling, general and administrative expenses are expensed as incurred. Selling, general and administrative expenses consist primarily of salaries and related costs for personnel, including stock-based compensation and travel expenses for the Company’s employees in executive, operational, finance, legal, business development, commercial, information technology, and human resource functions. Other selling, general and administrative expenses include facility-related costs, professional fees for accounting, tax, legal and consulting services, directors’ fees and expenses associated with obtaining and maintaining patents.
Research and development expenses	Research and development expenses Research and development costs are charged to expense as costs are incurred in performing research and development activities, including salaries and benefits, facilities costs, overhead costs, clinical study and related clinical manufacturing costs, CMO and CTO costs, contract research organization ("CRO") costs, license and milestone fees, contract services, manufacturing costs for pre-launch inventory that did not qualify for capitalization, and other related costs. Up-front fees and milestones paid to third parties in connection with technologies which have not reached technological feasibility and do not have an alternative future use are expensed as research and development expense as incurred. In circumstances where amounts have been paid in excess of costs incurred, the Company records a prepaid expense. The Company accrues costs for clinical trial activities based upon estimates of the services received and related expenses incurred that have yet to be invoiced by the contract research organizations, clinical study sites, laboratories, consultants, or other clinical trial vendors that perform the activities.
Cost of product revenue	Cost of product revenue
Stock-based compensation	Stock-based compensation The Company’s share-based compensation programs grant awards that have included stock options, restricted stock units, restricted stock awards, unrestricted stock awards and shares issued under its employee stock purchase plan. Grants are awarded to employees and non-employees, including the Company's board of directors. The Company accounts for its stock-based compensation awards in accordance with FASB ASC Topic 718, Compensation—Stock Compensation (“ASC 718”). ASC 718 requires all stock-based payments, including grants of stock options and restricted stock units and modifications to existing stock options, to be recognized in the consolidated statements of operations and comprehensive loss based on their fair values. The Company’s stock-based awards are subject to either service or performance-based vesting conditions. Compensation expense related to awards with service-based vesting conditions is recognized on a straight-line basis based on the grant date fair value over the associated service period of the award, which is generally the vesting term. Compensation expense related to awards with performance-based vesting conditions is recognized based on the grant date fair value over the requisite service period using the accelerated attribution method to the extent achievement of the performance condition is probable. The Company estimates the fair value of its option awards using the Black-Scholes option pricing model, which requires the input of subjective assumptions, including (i) the expected stock price volatility, (ii) the calculation of expected term of the award, (iii) the risk-free interest rate, and (iv) expected dividends. Effective January 1, 2020, the Company eliminated the use of a representative peer group and uses only its own historical volatility data in its estimate of expected volatility given that there is now a sufficient amount of historical information regarding the volatility of its own stock price. For both employee and non-employee awards, the measurement date is the date of grant. The Company has estimated the expected term of its employee stock options using the “simplified” method, whereby, the expected term equals the arithmetic average of the vesting term and the original contractual term of the option due to its lack of sufficient historical data. The risk-free interest rates for periods within the expected term of the option are based on the U.S. Treasury securities with a maturity date commensurate with the expected term of the associated award. The Company has never paid, and does not expect to pay, dividends in the foreseeable future. The Company accounts for forfeitures as they occur. Stock-based compensation expense recognized in the financial statements is based on awards for which performance or service conditions are expected to be satisfied. Conversion and modification of equity awards outstanding at date of separation of 2seventy bio In connection with the separation of 2seventy bio on November 4, 2021 (the "Separation"), under the provisions of the existing plans, the Company adjusted its outstanding equity awards in accordance with the terms of the Employee Matters Agreement (an equitable adjustment) to preserve the intrinsic value of the awards immediately before and after the Separation. These modified awards otherwise retained substantially the same terms and conditions, including term and vesting provisions. The Company will recognize future expense for awards denominated in bluebird stock and 2seventy bio stock granted to the Company's employees as a result of the separation of 2seventy bio. Expense related to awards denominated in bluebird stock granted to 2seventy bio employees will be incurred by 2seventy bio. Stock-based compensation expense related to modified awards is measured based on the fair value for the awards as of the modification date. Any incremental stock-based compensation expense arising from the excess of the fair value of the awards on the modification date compared to the fair value of the awards immediately before the modification date is recognized at the modification date or ratably over the requisite remaining service period, as appropriate.
Interest income	Interest income Interest income consists primarily of interest income earned on investments.
Interest expense	Interest expense Interest expense consists primarily of the interest expense on finance lease arrangements.
Other income (expense), net	Other income, net Other income, net consists primarily of sublease income, gains and losses on disposal of assets, and gains and losses on foreign currency.
Net loss per share	Net loss per share Basic net loss per share is calculated by dividing net loss attributable to common stockholders by the weighted average number of common shares outstanding during the period, including the shares of common stock issuable upon the exercise of warrants that are exercisable for little or no consideration. Diluted net loss per share is calculated by dividing the net loss attributable to common stockholders by the weighted-average number of common equivalent shares outstanding for the period, including the shares of common stock issuable upon the exercise of warrants that are exercisable for little or no consideration as well as any dilutive effect from outstanding stock options, unvested restricted stock, restricted stock units, and employee stock purchase plan stock using the treasury stock method. Given that the Company recorded a net loss for each of the periods presented, there is no difference between basic and diluted net loss per share since the effect of common stock equivalents would be anti-dilutive and are, therefore, excluded from the diluted net loss per share calculation. The Company follows the two-class method when computing net loss per share in periods when issued shares that meet the definition of participating securities are outstanding. The two-class method determines net loss per share for each class of common and participating securities according to dividends declared or accumulated and participation rights in undistributed earnings. The two-class method requires income available to common stockholders for the period to be allocated between common and participating securities based upon their respective rights to receive dividends as if all income for the period had been distributed. Accordingly, in periods in which the Company reports a net loss attributable to common stockholders when participating securities are outstanding, losses are not allocated to the participating securities.
Income taxes	Income taxes Income taxes are recorded in accordance with FASB ASC Topic 740, Income Taxes (“ASC 740”), which provides for deferred taxes using an asset and liability approach. The Company recognizes deferred tax assets and liabilities for the expected future tax consequences of events that have been included in the financial statements or tax returns. Deferred tax assets and liabilities are determined based on the difference between the financial statement and tax bases of assets and liabilities using enacted tax rates in effect for the year in which the differences are expected to reverse. Valuation allowances are provided, if based upon the weight of available evidence, it is more likely than not that some or all of the deferred tax assets will not be realized. The Company accounts for uncertain tax positions in accordance with the provisions of ASC 740. When uncertain tax positions exist, the Company recognizes the tax benefit of tax positions to the extent that the benefit will more likely than not be realized. The determination as to whether the tax benefit will more likely than not be realized is based upon the technical merits of the tax position as well as consideration of the available facts and circumstances. The Company accrues for potential interest and penalties related to unrecognized tax benefits in income tax expense.
Comprehensive loss	omprehensive loss Comprehensive loss is composed of net loss and other comprehensive income (loss). Other comprehensive income (loss) consists of unrealized gains and losses on debt securities, foreign currency translation adjustments and other items.
Restructuring expenses	Restructuring expenses The Company records costs and liabilities associated with exit and disposal activities in accordance with FASB ASC Topic 420, Exit or Disposal Cost Obligations ("ASC 420") and Topic 712, Compensation - Nonretirement Postemployment Benefits ("ASC 712"). Such costs are based on estimates of fair value in the period liabilities are incurred. The Company evaluates and adjusts these costs as appropriate for changes in circumstances as additional information becomes available. Refer to Note 19, Reduction in workforce, for more information .
Recent accounting pronouncements	Recent accounting pronouncements In November 2023, the FASB issued ASU 2023-07, Segment Reporting (Topic 280): Improvements to Reportable Segment Disclosures to update reportable segment disclosure requirements, primarily through enhanced disclosures about significant segment expenses and information used to assess segment performance and requires companies to disclose all annual disclosures about segments in interim periods. The ASU also requires companies with a single reportable segment to provide all disclosures required by Topic 280 – Segment Reporting. This update is effective beginning with the Company’s 2024 fiscal year annual reporting period and interim periods beginning thereafter. The Company is currently evaluating the impact that the adoption of this standard will have on its consolidated financial statements and disclosures. In December 2023, the FASB issued ASU 2023-09, Income Taxes (Topic 740): Improvements to Income Tax Disclosures . This ASU expands disclosures in an entity’s income tax rate reconciliation table and disclosures regarding taxes paid both in the U.S. and foreign jurisdictions. This update is effective beginning with the Company’s 2025 fiscal year annual reporting period. The Company is currently evaluating the impact to its income tax disclosures. In March 2024, the FASB issued ASU 2024-01, Compensation-Stock Compensation (Topic 718): Scope Application of Profits Interest and Similar Awards . This update clarifies the scope of "Profit Interest" and similar awards and adds an illustrative example to the existing ASC 718 standard that includes four fact patterns to demonstrate how an entity should apply the scope guidance in paragraph 718-10-15-3 to determine whether a profits interest award should be accounted for in accordance with Topic 718. The amendments in this ASU are effective for annual periods beginning after December 15, 2024, and interim periods within those annual periods. Early adoption is permitted for interim and annual financial statements not yet issued or made available for issuance. The amendments in this ASU should be applied either (1) retrospectively to all prior periods presented in the financial statements or (2) prospectively to profits interest and similar awards granted or modified on or after the date at which the entity first applies the amendments. The Company is currently evaluating the impact that the adoption of this standard will have on its consolidated financial statements and disclosures. In March 2024, the FASB issued ASU 2024-02 " Codification Improvements—Amendments to Remove References to the Concepts Statements ", which removes various references to concepts statements from the FASB Accounting Standards Codification. This ASU is effective for the Company beginning in the first quarter of fiscal year 2026, with early adoption permitted. The Company expects the new guidance will have an immaterial impact on its consolidated financial statements and intends to adopt the guidance when it becomes effective in the first quarter of fiscal year 2026.

Restatement of Previously Iss_2

Restatement of Previously Issued Financial Statements (Tables)	12 Months Ended
	Dec. 31, 2023
Accounting Changes and Error Corrections [Abstract]
Schedule of Error Corrections and Prior Period Adjustments	The following tables represent the as-restated consolidated balance sheet as of December 31, 2022, and the related consolidated statements of operations and comprehensive loss, stockholders’ equity and cash flows for the year ended December 31, 2022. These tables also present a reconciliation from the prior period as previously reported to the as-restated amounts. The amounts as previously reported for fiscal year 2022 were derived from the Annual Report on Form 10-K for the fiscal year ended December 31, 2022, filed on March 29, 2023. Consolidated Balance Sheet: As of December 31, 2022 (in thousands) As Previously Reported Adjustments to Leases Other Adjustments As Restated Assets Current assets: Cash and cash equivalents $ 113,006 $ — $ — $ 113,006 Marketable securities 67,321 — — 67,321 Prepaid expenses 8,374 244 — 8,618 Receivables and other current assets 10,787 3,840 — 14,627 Total current assets 199,488 4,084 — 203,572 Marketable securities 1,414 — — 1,414 Property, plant and equipment, net 9,362 58,585 (311) 67,636 Goodwill 5,646 — — 5,646 Intangible assets, net 4,868 — — 4,868 Operating lease right-of-use assets 281,996 (51,111) 230,885 Restricted cash and other non-current assets 52,128 3,665 — 55,793 Total assets $ 554,902 $ 15,223 $ (311) $ 569,814 Liabilities and Stockholders’ Equity Current Liabilities: Accounts payable $ 25,092 $ (10,225) $ — $ 14,867 Accrued expenses and other current liabilities 51,985 (520) 1,999 53,464 Operating lease liability, current portion 51,160 (23,566) — 27,594 Finance lease liability, current portion — 60,654 — 60,654 Total current liabilities 128,237 26,343 1,999 156,579 Operating lease liability, net of current portion 230,230 (21,102) — 209,128 Financing lease liability, net of current portion — 69,682 — 69,682 Other non-current liabilities 92 — — 92 Total liabilities 358,559 74,923 1,999 435,481 Commitments and contingencies (Note 12) Stockholders’ Equity: Preferred stock, $0.01 par value, 5,000 shares authorized; 0 shares issued and outstanding at December 31, 2022 $ — $ — $ — $ — Common stock, $0.01 par value, 125,000 shares authorized; 82,923 shares issued and outstanding at December 31, 2022 830 — — 830 Additional paid-in capital 4,186,086 — (98) 4,185,988 Accumulated other comprehensive loss (4,070) — — (4,070) Accumulated deficit (3,986,503) (59,700) (2,212) (4,048,415) Total stockholders’ equity 196,343 (59,700) (2,310) 134,333 Total liabilities and stockholders’ equity $ 554,902 $ 15,223 $ (311) $ 569,814 Consolidated Statement of Operations and Comprehensive Loss Year ended December 31, 2022 (in thousands, except per share amounts) As Previously Reported Adjustments to Leases Other Adjustments As Restated Revenue: Product revenue, net $ 2,739 $ — $ — $ 2,739 Other revenue 858 — — 858 Total revenues 3,597 — — 3,597 Cost of product revenue 10,077 — — 10,077 Gross margin (6,480) — — (6,480) Operating expenses: Research and development 240,764 (40,121) (204) 200,439 Selling, general and administrative 136,908 3,516 (98) 140,326 Restructuring expenses 4,940 — — 4,940 Total operating expenses 382,612 (36,605) (302) 345,705 Gain from sale of priority review voucher, net 102,000 — — 102,000 (Loss) Income from operations (287,092) 36,605 302 (250,185) Interest income 1,032 — — 1,032 Interest expense — (6,322) — (6,322) Other (expense) income, net 19,599 5,651 — 25,250 (Loss) income before income taxes (266,461) 35,934 302 (230,225) Income tax (expense) benefit (117) — — (117) Net (loss) income (266,578) 35,934 302 (230,342) Net (loss) income per share - basic $ (3.39) $ 0.46 $ — $ (2.93) Net (loss) income per share - diluted $ (3.39) $ 0.46 $ — $ (2.93) Weighted-average number of common shares used in computing net (loss) income per share - basic: 78,585 — — 78,585 Weighted-average number of common shares used in computing net (loss) income per share - diluted: 78,585 — — 78,585 Other comprehensive (loss) income: Other comprehensive (loss) income, net of tax (benefit) expense of $0.0 million for the year ended December 31, 2022 (1,159) — — (1,159) Total other comprehensive (loss) income (1,159) — — (1,159) Comprehensive (loss) income $ (267,737) $ 35,934 $ 302 $ (231,501) Consolidated Statement of Changes in Stockholders' Equity: Common stock Additional Accumulated Accumulated Total (in thousands) Shares Amount As Previously Reported Balances at December 31, 2021 71,115 $ 711 $ 4,096,402 $ (2,911) $ (3,719,925) $ 374,277 Vesting of restricted stock 979 10 (10) — — — Exercise of stock options 7 — 16 — — 16 Purchase of shares under ESPP 68 1 238 — — 239 Issuance of common stock 10,742 107 53,960 — — 54,067 Issuance of unrestricted stock awards to settle accrued employee compensation 12 1 — — — 1 Stock-based compensation expense — — 35,480 — — 35,480 Other comprehensive loss — — — (1,159) — (1,159) Net (loss) income — — — — (266,578) (266,578) Balances at December 31, 2022 82,923 $ 830 $ 4,186,086 $ (4,070) $ (3,986,503) $ 196,343 Adjustments to Leases Balances at December 31, 2021 — $ — $ — $ — $ (95,634) $ (95,634) Vesting of restricted stock — — — — — — Exercise of stock options — — — — — — Purchase of shares under ESPP — — — — — — Issuance of common stock — — — — — — Issuance of unrestricted stock awards to settle accrued employee compensation — — — — — — Stock-based compensation expense — — — — — — Other comprehensive loss — — — — — — Net (loss) income — — — — 35,934 35,934 Balances at December 31, 2022 — $ — $ — $ — $ (59,700) $ (59,700) Other Adjustments Balances at December 31, 2021 — — — — (2,514) (2,514) Vesting of restricted stock — — — — — — Exercise of stock options — — — — — — Purchase of shares under ESPP — — — — — — Issuance of common stock — — — — — — Issuance of unrestricted stock awards to settle accrued employee compensation — — — — — — Stock-based compensation expense — — (98) — — (98) Other comprehensive loss — — — — — — Net (loss) income — — — — 302 302 Balances at December 31, 2022 — $ — $ (98) $ — $ (2,212) $ (2,310) As Restated Balances at December 31, 2021 71,115 711 4,096,402 (2,911) (3,818,073) 276,129 Vesting of restricted stock 979 10 (10) — — — Exercise of stock options 7 — 16 — — 16 Purchase of shares under ESPP 68 1 238 — — 239 Issuance of common stock 10,742 107 53,960 — — 54,067 Issuance of unrestricted stock awards to settle accrued employee compensation 12 1 — — — 1 Stock-based compensation expense — — 35,382 — — 35,382 Other comprehensive loss — — — (1,159) — (1,159) Net (loss) income — — — — (230,342) (230,342) Balances at December 31, 2022 82,923 $ 830 $ 4,185,988 $ (4,070) $ (4,048,415) $ 134,333 Consolidated Statement of Cash Flows Year Ended December 31, 2022 (in thousands) As Previously Reported Adjustments to Leases Other Adjustments As Restated Cash flows from operating activities: Net (loss) income $ (266,578) $ 35,934 $ 302 $ (230,342) Adjustments to reconcile net loss to net cash used in operating activities: Depreciation and amortization 5,001 3,547 (204) 8,344 Stock-based compensation expense 35,188 — (98) 35,090 Noncash research and development expense (finance lease) — 11,180 — 11,180 Noncash operating lease expense — 23,562 — 23,562 Gain from sale of priority review voucher (102,000) — — (102,000) Unrealized loss on equity securities 3,135 — — 3,135 Excess inventory reserve 7,519 — — 7,519 Other non-cash items 3,904 234 — 4,138 (Gain) on foreign currency exchange rates — (1,801) — (1,801) Changes in operating assets and liabilities: Prepaid expenses and other assets 3,260 (8,080) — (4,820) Inventory (7,227) — — (7,227) Operating right of use assets 42,706 (42,706) — — Accounts payable (920) (6,789) — (7,709) Accrued expenses and other liabilities (51,228) 5,254 — (45,974) Accrued interest payable under finance lease — 4,758 — 4,758 Operating lease liabilities (25,713) 11,641 — (14,072) Net cash used in operating activities (352,953) 36,734 — (316,219) Cash flows from investing activities: Purchase of property, plant and equipment (8,208) — — (8,208) Proceeds from maturities of marketable securities 131,445 — — 131,445 Proceeds from sales of marketable securities 30,216 — — 30,216 Purchase of intangible assets (5,000) — — (5,000) Proceeds from sale of priority review voucher 102,000 — — 102,000 Net cash provided by investing activities 250,453 — — 250,453 Cash flows from financing activities: Proceeds from exercise of stock options and ESPP contributions 16 — — 16 Principal payments on finance lease — (36,734) — (36,734) Proceeds from public offering of common stock, net of issuance costs 54,237 — — 54,237 Net cash provided by financing activities 54,253 (36,734) — 17,519 (Decrease) increase in cash, cash equivalents and restricted cash (48,247) — — (48,247) Cash, cash equivalents and restricted cash at beginning of year 206,692 — — 206,692 Cash, cash equivalents and restricted cash at end of year $ 158,445 $ — $ — $ 158,445 Reconciliation of cash, cash equivalents and restricted cash: Cash and cash equivalents $ 113,006 $ — $ — $ 113,006 Restricted cash included in receivables and other current assets 1,502 — — 1,502 Restricted cash included in restricted cash and other non-current assets 43,937 — — 43,937 Total cash, cash equivalents and restricted cash $ 158,445 $ — $ — $ 158,445 Supplemental cash flow disclosures: Right-of-use assets obtained in exchange for operating lease liabilities 236,003 (14,967) — 221,036 Increase (Reduction) of right of use asset and associated operating lease liability due to lease reassessment (2,833) 2,833 — — Purchases of property, plant and equipment included in accounts (3) — — (3) Offering expenses included in accounts payable and accrued expenses 170 — — 170 Right-of-use assets obtained in exchange for finance lease liabilities — 73,443 — 73,443 Cash paid during the period for income taxes 253 — — 253 The following unaudited condensed consolidated balance sheet tables present the impacts of the restatement adjustments as of the periods ended March 31, 2023 and 2022, June 30, 2023 and 2022, and September 30, 2023 and 2022. The period ended December 31, 2023 was not subject to restatement. As of March 31, 2023 (in thousands) As Previously Reported Adjustments to Leases Other Adjustments As Restated Assets Current assets: Cash and cash equivalents $ 239,045 $ — $ — $ 239,045 Marketable securities 79,212 — — 79,212 Prepaid expenses 13,466 (2,082) — 11,384 Inventory 3,809 (610) — 3,199 Receivables and other current assets 15,539 3,374 (2,800) 16,113 Total current assets 351,071 682 (2,800) 348,953 Property, plant and equipment, net 8,718 53,223 (270) 61,671 Goodwill 5,646 — — 5,646 Intangible assets, net 5,613 — — 5,613 Operating lease right-of-use assets 270,153 (46,690) — 223,463 Restricted cash and other non-current assets 51,535 3,665 — 55,200 Total assets $ 692,736 $ 10,880 $ (3,070) $ 700,546 Liabilities and Stockholders’ Equity Current Liabilities: Accounts payable $ 19,235 $ (2,522) $ — $ 16,713 Accrued expenses and other current liabilities 45,294 1,017 (801) 45,510 Operating lease liability, current portion 51,404 (24,784) 26,620 Financing lease liability, current portion — 58,747 — 58,747 Total current liabilities 115,933 32,458 (801) 147,590 Operating lease liability, net of current portion 221,971 (18,176) 203,795 Financing lease liability, net of current portion — 58,649 — 58,649 Other non-current liabilities 92 — — 92 Total liabilities 337,996 72,931 (801) 410,126 Commitments and contingencies (Note 12) Stockholders’ Equity: Preferred stock, $0.01 par value, 5,000 shares authorized; 0 shares issued and outstanding at March 31, 2023 $ — $ — $ — $ — Common stock, $0.01 par value, 125,000 shares authorized; 106,370 shares issued and outstanding at March 31, 2023 1,064 — — 1,064 Additional paid-in capital 4,322,025 — (98) 4,321,927 Accumulated other comprehensive loss (3,086) — — (3,086) Accumulated deficit (3,965,263) (62,051) (2,171) (4,029,485) Total stockholders’ equity 354,740 (62,051) (2,269) 290,420 Total liabilities and stockholders’ equity $ 692,736 $ 10,880 $ (3,070) $ 700,546 As of June 30, 2023 (in thousands) As Previously Reported Adjustments to Leases Other Adjustments As Restated Assets Current assets: Cash and cash equivalents $ 172,872 $ — $ — $ 172,872 Marketable securities 72,431 — — 72,431 Prepaid expenses 13,597 (2,162) — 11,435 Inventory 13,642 (1,838) 602 12,406 Receivables and other current assets 15,435 3,659 19,094 Total current assets 287,977 (341) 602 288,238 Property, plant and equipment, net 10,227 51,722 (235) 61,714 Goodwill 5,646 — — 5,646 Intangible assets, net 5,490 — — 5,490 Operating lease right-of-use assets 302,849 (86,929) 215,920 Restricted cash and other non-current assets 51,204 3,665 — 54,869 Total assets $ 663,393 $ (31,883) $ 367 $ 631,877 Liabilities and Stockholders’ Equity Current Liabilities: Accounts payable $ 10,894 $ (1,081) $ — $ 9,813 Accrued expenses and other current liabilities 56,531 (599) 1,999 57,931 Operating lease liability, current portion 67,591 (42,427) — 25,164 Financing lease liability, current portion — 55,706 — 55,706 Total current liabilities 135,016 11,599 1,999 148,614 Operating lease liability, net of current portion 239,266 (40,930) 198,336 Financing lease liability, net of current portion — 50,017 — 50,017 Other non-current liabilities 92 — — 92 Total liabilities 374,374 20,686 1,999 397,059 Commitments and contingencies (Note 12) Stockholders’ Equity: Preferred stock, $0.01 par value, 5,000 shares authorized; 0 shares issued and outstanding at June 30, 2023 $ — $ — $ — $ — Common stock, $0.01 par value, 250,000 shares authorized; 106,454 shares issued and outstanding at June 30, 2023 1,065 — — 1,065 Additional paid-in capital 4,328,489 — (98) 4,328,391 Accumulated other comprehensive loss (2,364) — — (2,364) Accumulated deficit (4,038,171) (52,569) (1,534) (4,092,274) Total stockholders’ equity 289,019 (52,569) (1,632) 234,818 Total liabilities and stockholders’ equity $ 663,393 $ (31,883) $ 367 $ 631,877 As of September 30, 2023 (in thousands) As Previously Reported Adjustments to Leases Other Adjustments As Restated Assets Current assets: Cash and cash equivalents $ 165,347 $ — $ — $ 165,347 Marketable securities 8,946 — — 8,946 Accounts Receivable 23,000 — (8,400) 14,600 Prepaid expenses 11,431 (2,040) — 9,391 Inventory 20,969 (3,205) 602 18,366 Other current assets 17,383 3,538 20,921 Total current assets 247,076 (1,707) (7,798) 237,571 Property, plant and equipment, net 9,972 63,398 (280) 73,090 Goodwill 5,646 — — 5,646 Intangible assets, net 5,368 — — 5,368 Operating lease right-of-use assets 294,717 (87,796) 206,921 Restricted cash and other non-current assets 50,829 3,665 — 54,494 Total assets $ 613,608 $ (22,440) $ (8,078) $ 583,090 Liabilities and Stockholders’ Equity Current Liabilities: Accounts payable $ 19,852 $ (3,042) $ 316 $ 17,126 Deferred revenue 9,653 — (8,400) 1,253 Accrued expenses and other current liabilities 57,768 572 — 58,340 Operating lease liability, current portion 71,684 (46,160) — 25,524 Financing lease liability, current portion — 85,208 — 85,208 Total current liabilities 158,957 36,578 (8,084) 187,451 Operating lease liability, net of current portion 232,023 (39,456) — 192,567 Financing lease liability, net of current portion — 50,146 — 50,146 Other non-current liabilities 92 — — 92 Total liabilities 391,072 47,268 (8,084) 430,256 Commitments and contingencies (Note 12) Stockholders’ Equity: Preferred stock, $0.01 par value, 5,000 shares authorized; 0 shares issued and outstanding at September 30, 2023 $ — $ — $ — $ — Common stock, $0.01 par value, 250,000 shares authorized; 107,022 shares issued and outstanding at September 30, 2023 1,071 — — 1,071 Additional paid-in capital 4,333,594 — (98) 4,333,496 Accumulated other comprehensive loss (2,227) — — (2,227) Accumulated deficit (4,109,902) (69,708) 104 (4,179,506) Total stockholders’ equity 222,536 (69,708) 6 152,834 Total liabilities and stockholders’ equity $ 613,608 $ (22,440) $ (8,078) $ 583,090 As of March 31, 2022 (in thousands) As Previously Reported Adjustments to Leases Other Adjustments As Restated Assets Current assets: Cash and cash equivalents $ 106,260 $ — $ — $ 106,260 Marketable securities 105,328 — — 105,328 Prepaid expenses 31,798 (1,549) — 30,249 Receivables and other current assets 11,531 198 — 11,729 Total current assets 254,917 (1,351) — 253,566 Marketable securities 55,049 — — 55,049 Property, plant and equipment, net 11,234 (599) (459) 10,176 Goodwill 5,646 — — 5,646 Operating lease right-of-use assets 111,897 (61,082) — 50,815 Restricted cash and other non-current assets 52,328 3,665 — 55,993 Total assets $ 491,071 $ (59,367) $ (459) $ 431,245 Liabilities and Stockholders’ Equity Current Liabilities: Accounts payable $ 28,350 $ (4,937) $ — $ 23,413 Accrued expenses and other current liabilities 89,032 (15,597) 1,999 75,434 Operating lease liability, current portion 25,510 (9,262) — 16,248 Financing lease liability, current portion — 55,995 — 55,995 Total current liabilities 142,892 26,199 1,999 171,090 Operating lease liability, net of current portion 84,828 (46,407) — 38,421 Financing lease liability, net of current portion — 41,315 — 41,315 Other non-current liabilities 92 — — 92 Total liabilities 227,812 21,107 1,999 250,918 Commitments and contingencies (Note 12) Stockholders’ Equity: Preferred stock, $0.01 par value, 5,000 shares authorized; 0 shares issued and outstanding at March 31, 2022 $ — $ — $ — $ — Common stock, $0.01 par value, 125,000 shares authorized; 71,438 shares issued and outstanding at March 31, 2022 714 — — 714 Additional paid-in capital 4,109,081 — (1,384) 4,107,697 Accumulated other comprehensive loss (4,459) — — (4,459) Accumulated deficit (3,842,077) (80,474) (1,074) (3,923,625) Total stockholders’ equity 263,259 (80,474) (2,458) 180,327 Total liabilities and stockholders’ equity $ 491,071 $ (59,367) $ (459) $ 431,245 As of June 30, 2022 (in thousands) As Previously Reported Adjustments to Leases Other Adjustments As Restated Assets Current assets: Cash and cash equivalents $ 81,499 $ — $ — $ 81,499 Marketable securities 51,010 — — 51,010 Prepaid expenses 24,473 (667) — 23,806 Receivables and other current assets 10,476 2,997 — 13,473 Total current assets 167,458 2,330 — 169,788 Marketable securities 40,641 — — 40,641 Property, plant and equipment, net 14,566 (688) (406) 13,472 Goodwill 5,646 — — 5,646 Operating lease right-of-use assets 292,731 (54,005) — 238,726 Restricted cash and other non-current assets 52,550 3,665 — 56,215 Total assets $ 573,592 $ (48,698) $ (406) $ 524,488 Liabilities and Stockholders’ Equity Current Liabilities: Accounts payable $ 24,865 $ (2,846) $ — $ 22,019 Accrued expenses and other current liabilities 75,550 (12,189) 1,999 65,360 Operating lease liability, current portion 48,446 (22,583) — 25,863 Financing lease liability, current portion — 47,219 — 47,219 Total current liabilities 148,861 9,601 1,999 160,461 Operating lease liability, net of current portion 244,522 (27,634) — 216,888 Financing lease liability, net of current portion — 36,550 — 36,550 Other non-current liabilities 93 — — 93 Total liabilities 393,476 18,517 1,999 413,992 Commitments and contingencies (Note 12) Stockholders’ Equity: Preferred stock, $0.01 par value, 5,000 shares authorized; 0 shares issued and outstanding at June 30, 2022 $ — $ — $ — $ — Common stock, $0.01 par value, 125,000 shares authorized; 73,551 shares issued and outstanding at June 30, 2022 735 — — 735 Additional paid-in capital 4,126,012 — (1,854) 4,124,158 Accumulated other comprehensive loss (4,416) — — (4,416) Accumulated deficit (3,942,215) (67,215) (551) (4,009,981) Total stockholders’ equity 180,116 (67,215) (2,405) 110,496 Total liabilities and stockholders’ equity $ 573,592 $ (48,698) $ (406) $ 524,488 As of September 30, 2022 (in thousands) As Previously Reported Adjustments to Leases Other Adjustments As Restated Assets Current assets: Cash and cash equivalents $ 66,478 $ — $ — $ 66,478 Marketable securities 73,155 — — 73,155 Prepaid expenses 8,270 55 — 8,325 Receivables and other current assets 12,535 2,425 — 14,960 Total current assets 160,438 2,480 — 162,918 Marketable securities 1,407 — — 1,407 Property, plant and equipment, net 11,535 (777) (358) 10,400 Goodwill 5,646 — — 5,646 Intangible assets, net — — 4,972 4,972 Operating lease right-of-use assets 288,684 (56,750) — 231,934 Restricted cash and other non-current assets 52,388 3,665 — 56,053 Total assets $ 520,098 $ (51,382) $ 4,614 $ 473,330 Liabilities and Stockholders’ Equity Current Liabilities: Accounts payable $ 18,622 $ (2,898) $ — $ 15,724 Accrued expenses and other current liabilities 64,314 (13,432) 1,998 52,880 Operating lease liability, current portion 43,791 (20,322) — 23,469 Financing lease liability, current portion — 41,264 — 41,264 Total current liabilities 126,727 4,612 1,998 133,337 Operating lease liability, net of current portion 234,422 (24,069) — 210,353 Financing lease liability, net of current portion — 31,036 — 31,036 Other non-current liabilities 92 — — 92 Total liabilities 361,241 11,579 1,998 374,818 Commitments and contingencies (Note 12) Stockholders’ Equity: Preferred stock, $0.01 par value, 5,000 shares authorized; 0 shares issued and outstanding at September 30, 2022 $ — $ — $ — $ — Common stock, $0.01 par value, 125,000 shares authorized; 82,880 shares issued and outstanding at September 30, 2022 829 — — 829 Additional paid-in capital 4,181,393 — (2,043) 4,179,350 Accumulated other comprehensive loss (4,630) — — (4,630) Accumulated deficit (4,018,735) (62,961) 4,659 (4,077,037) Total stockholders’ equity 158,857 (62,961) 2,616 98,512 Total liabilities and stockholders’ equity $ 520,098 $ (51,382) $ 4,614 $ 473,330 Condensed Consolidated Statements of Operations and Comprehensive Loss The following unaudited condensed consolidated statements of operations and comprehensive loss tables present the impacts of the restatement adjustments for the three months ended March 31, 2023 and 2022, the three and six months ended June 30, 2023 and 2022, and the three and nine months ended September 30, 2023 and 2022. The year ended December 31, 2023 was not subject to restatement. Three Months ended March 31, 2023 (in thousands, except per share amounts) As Previously Reported Adjustments to Leases Other Adjustments As Restated Revenue Product revenue $ 2,296 $ — $ — $ 2,296 Other revenue 85 — — 85 Total revenues 2,381 — — 2,381 Cost of product revenue 3,376 2,136 — 5,512 Gross margin (995) (2,136) — (3,131) Operating expenses: Selling, general and administrative 37,354 113 — 37,467 Research and development 46,144 (4,516) (41) 41,587 Total operating expenses 83,498 (4,403) (41) 79,054 Gain from sale of priority review voucher, net 92,930 — — 92,930 Income (loss) from operations 8,437 2,267 41 10,745 Interest income 2,828 — — 2,828 Interest expense (3) (4,267) — (4,270) Other income, net 9,978 (351) — 9,627 Income (loss) before income taxes 21,240 (2,351) 41 18,930 Income tax (expense) benefit — — — — Net income (loss) 21,240 (2,351) 41 18,930 Net income (loss) per share - basic (1) $ 0.21 $ (0.02) $ — $ 0.18 Net income (loss) per share - diluted (1) $ 0.21 $ (0.02) $ — $ 0.18 Weighted-average number of common shares used in computing net income (loss) per share - basic: 102,920 — — 102,920 Weighted-average number of common shares used in computing net income (loss) per share - diluted: 103,303 — — 103,303 Other comprehensive income (loss): Other comprehensive income (loss), net of tax (benefit) expense of $0.0 million for the three months ended March 31, 2023 984 — — 984 Total other comprehensive income (loss) 984 — — 984 Comprehensive income (loss) $ 22,224 $ (2,351) $ 41 $ 19,914 (1) Due to differences in rounding to the nearest cent per basic or diluted share, totals may not equal the sum of the line items. Six Months ended June 30, 2023 (in thousands, except per share amounts) As Previously Reported Adjustments to Leases Other Adjustments As Restated Revenue Product revenue $ 9,133 $ — $ — $ 9,133 Other revenue 138 — — 138 Total revenues 9,271 — — 9,271 Cost of product revenue 12,940 (731) — 12,209 Gross margin (3,669) 731 — (2,938) Operating expenses: Selling, general and administrative 77,703 226 — 77,929 Research and development 88,418 (14,705) (678) 73,035 Total operating expenses 166,121 (14,479) (678) 150,964 Gain from sale of priority review voucher, net 92,930 — — 92,930 Income (loss) from operations (76,860) 15,210 678 (60,972) Interest income 5,507 — — 5,507 Interest expense (3) (8,017) — (8,020) Other income, net 19,608 (62) — 19,546 Income (loss) before income taxes (51,748) 7,131 678 (43,939) Income tax (expense) benefit 80 — 80 Net income (loss) (51,668) 7,131 678 (43,859) Net income (loss) per share - basic $ (0.49) $ 0.07 $ 0.01 $ (0.41) Net income (loss) per share - diluted $ (0.49) $ 0.07 $ 0.01 $ (0.41) Weighted-average number of common shares used in computing net income (loss) per share - basic: 105,819 — — 105,819 Weighted-average number of common shares used in computing net income (loss) per share - diluted: 105,819 — — 105,819 Other comprehensive income (loss): Other comprehensive income (loss), net of tax (benefit) expense of $0.0 million for the six months ended June 30, 2023 1,706 — — 1,706 Total other comprehensive income (loss) 1,706 — — 1,706 Comprehensive income (loss) $ (49,962) $ 7,131 $ 678 $ (42,153) Three Months ended June 30, 2023 (in thousands, except per share amounts) As Previously Reported Adjustments to Leases Other Adjustments As Restated Revenue Product revenue $ 6,837 $ — $ — $ 6,837 Other revenue 53 — — 53 Total revenues 6,890 — — 6,890 Cost of product revenue 9,564 (2,867) — 6,697 Gross margin (2,674) 2,867 — 193 Operating expenses: — Selling, general and administrative 40,349 113 — 40,462 Research and development 42,274 (10,189) (637) 31,448 Total operating expenses 82,623 (10,076) (637) 71,910 Income (loss) from operations (85,297) 12,943 637 (71,717) Interest income 2,679 — — 2,679 Interest expense — (3,750) — (3,750) Other income, net 9,630 289 — 9,919 Income (loss) before income taxes (72,988) 9,482 637 (62,869) Income tax (expense) benefit 80 — — 80 Net income (loss) (72,908) 9,482 637 (62,789) Net income (loss) per share - basic (1) $ (0.67) $ 0.09 $ 0.01 $ (0.58) Net income (loss) per share - diluted (1) $ (0.67) $ 0.09 $ 0.01 $ (0.58) Weighted-average number of common shares used in computing net income (loss) per share - basic: 108,685 — — 108,685 Weighted-average number of common shares used in computing net income (loss) per share - diluted: 108,685 — — 108,685 Other comprehensive income (loss): Other comprehensive income (loss), net of tax (benefit) expense of $0.0 million for the three months ended June 30, 2023 722 — — 722 Total other comprehensive income (loss) 722 — — 722 Comprehensive income (loss) $ (72,186) $ 9,482 $ 637 $ (62,067) (1) Due to differences in rounding to the nearest cent per basic or diluted share, totals may not equal the sum of the line items. Nine Months ended September 30, 2023 (in thousands, except per share amounts) As Previously Reported Adjustments to Leases Other Adjustments As Restated Revenue Product revenue $ 21,414 $ — $ — $ 21,414 Other revenue 249 — — 249 Total revenues 21,663 — — 21,663 Cost of product revenue 23,895 (2,560) — 21,335 Gross margin (2,232) 2,560 — 328 Operating expenses: — Selling, general and administrative 118,406 294 — 118,700 Research and development 133,881 52 (2,397) 131,536 Total operating expenses 252,287 346 (2,397) 250,236 Gain from sale of priority review voucher, net 92,930 — — 92,930 Income (loss) from operations (161,589) 2,214 2,397 (156,978) Interest income 7,961 — — 7,961 Interest expense (3) (12,328) — (12,331) Other income (expense), net 30,152 106 (81) 30,177 Income (loss) before income taxes (123,479) (10,008) 2,316 (131,171) Income tax (expense) benefit 80 — — 80 Net income (loss) (123,399) (10,008) 2,316 (131,091) Net income (loss) per share - basic (1) $ (1.15) $ (0.09) $ 0.02 $ (1.23) Net income (loss) per share - diluted (1) $ (1.15) $ (0.09) $ 0.02 $ (1.23) Weighted-average number of common shares used in computing net income (loss) per share - basic: 106,924 — — 106,924 Weighted-average number of common shares used in computing net income (loss) per share - diluted: 106,924 — — 106,924 Other comprehensive income (loss): Other comprehensive income (loss), net of tax (benefit) expense of $0.0 million for the nine months ended September 30, 2023 1,843 — — 1,843 Total other comprehensive income (loss) 1,843 — — 1,843 Comprehensive income (loss) $ (121,556) $ (10,008) $ 2,316 $ (129,248) (1) Due to differences in rounding to the nearest cent per basic or diluted share, totals may not equal the sum of the line items. Three Months ended September 30, 2023 (in thousands, except per share amounts) As Previously Reported Adjustments to Leases Other Adjustments As Restated Revenue Product revenue $ 12,281 $ — $ — $ 12,281 Other revenue 111 — — 111 Total revenues 12,392 — — 12,392 Cost of product revenue 10,955 (1,829) — 9,126 Gross margin 1,437 1,829 — 3,266 Operating expenses: Selling, general and administrative 40,703 68 — 40,771 Research and development 45,463 14,757 (1,719) 58,501 Total operating expenses 86,166 14,825 (1,719) 99,272 Income (loss) from operations (84,729) (12,996) 1,719 (96,006) Interest income 2,454 — — 2,454 Interest expense — (4,311) — (4,311) Other income (expense), net 10,544 168 (81) 10,631 Income (loss) before income taxes (71,731) (17,139) 1,638 (87,232) Income tax (expense) benefit — — — — Net income (loss) (71,731) (17,139) 1,638 (87,232) Net income (loss) per share - basic $ (0.66) $ (0.16) $ 0.02 $ (0.80) Net income (loss) per share - diluted $ (0.66) $ (0.16) $ 0.02 $ (0.80) Weighted-average number of common shares used in computing net income (loss) per share - basic: 109,098 — — 109,098 Weighted-average number of common shares used in computing net income (loss) per share - diluted: 109,098 — — 109,098 Other comprehensive income (loss): Other comprehensive income (loss), net of tax (benefit) expense of $0.0 million for the three months ended September 30, 2023 137 — — 137 Total other comprehensive income (loss) 137 — — 137 Comprehensive income (loss) $ (71,594) $ (17,139) $ 1,638 $ (87,095) Three Months ended March 31, 2022 (in thousands, except per share amounts) As Previously Reported Adjustments to Leases Other Adjustments As Restated Revenue: Product revenue $ 1,408 $ — $ — $ 1,408 Other revenue 537 — — 537 Total revenues 1,945 — — 1,945 Cost of product revenue 8,310 — — 8,310 Gross margin (6,365) — — (6,365) Operating expenses: Research and development 77,875 (15,511) (930) 61,434 Selling, general and administrative 36,106 (147) (510) 35,449 Total operating expenses 113,981 (15,658) (1,440) 96,883 Income (loss) from operations (120,346) 15,658 1,440 (103,248) Interest income 106 — — 106 Interest expense — (1,028) — (1,028) Other income (expense), net (1,912) 530 — (1,382) Income (loss) before income taxes (122,152) 15,160 1,440 (105,552) Income tax (expense) benefit — — — — Net income (loss) (122,152) 15,160 1,440 (105,552) Net income (loss) per share - basic $ (1.66) $ 0.21 $ 0.02 $ (1.43) Net income (loss) per share - diluted $ (1.66) $ 0.21 $ 0.02 $ (1.43) Weighted-average number of common shares used in computing net income (loss) per share - basic: 73,688 — — 73,688 Weighted-average number of common shares used in computing net income (loss) per share - diluted: 73,688 — — 73,688 Other comprehensive income (loss): Other comprehensive income (loss), net of tax (benefit) expense of $0.0 million for the three months ended March 31, 2022 (1,548) — — (1,548) Total other comprehensive income (loss) (1,548) — — (1,548) Comprehensive income (loss) $ (123,700) $ 15,160 $ 1,440 $ (107,100) Six Months ended June 30, 2022 (in thousands, except per share amounts) As Previously Reported Adjustments to Leases Other Adjustments As Restated Revenue: Product revenue $ 2,739 $ — $ — $ 2,739 Other revenue 725 — — 725 Total revenues 3,464 — — 3,464 Cost of product revenue 10,055 — — 10,055 Gross margin (6,591) — — (6,591) Operating expenses: Research and development 141,716 (27,866) (1,192) 112,658 Selling, general and administrative 72,800 (461) (771) 71,568 Restructuring expenses 6,639 — — 6,639 Total operating expenses 221,155 (28,327) (1,963) 190,865 Income (loss) from operations (227,746) 28,327 1,963 (197,456) Interest income 280 — — 280 Interest expense — (1,950) — (1,950) Other income, net 5,176 2,042 — 7,218 Income (loss) before income taxes (222,290) 28,419 1,963 (191,908) Income tax (expense) benefit — — — — Net income (loss) (222,290) 28,419 1,963 (191,90

Summary of significant accoun_3

Summary of significant accounting policies and basis of presentation (Tables)	12 Months Ended
	Dec. 31, 2023
Accounting Policies [Abstract]
Estimated Useful Lives of Assets	Depreciation and amortization is calculated using the straight-line method over the estimated useful lives of the assets, which are as follows: Asset Estimated useful life Building 40 years Computer equipment and software 3 years Furniture and fixtures 5 years Laboratory equipment 3-5 years Finance lease right-of-use asset Shorter of the useful life or remaining lease term Leasehold improvements Shorter of the useful life or remaining lease term

Product revenue and reserves (T

Product revenue and reserves (Tables)	12 Months Ended
	Dec. 31, 2023
Revenue from Contract with Customer [Abstract]
Disaggregation of Revenue	Product revenue by therapy represents: For the year ended December 31, 2023 2022 ZYNTEGLO $ 16,692 $ 2,739 SKYSONA 12,373 — Total product revenue $ 29,065 $ 2,739
Summary of Contract With Customer, Refund Liability	The following table summarizes an analysis of the change in reserves for gross to net deductions for the periods indicated: Total Balance at December 31, 2022 $ — Provision for rebates 5,365 Payments/credits — Balance at December 31, 2023 $ 5,365

Marketable securities (Tables)

Marketable securities (Tables)	12 Months Ended
	Dec. 31, 2023
Investments, Debt and Equity Securities [Abstract]
Summary of Marketable Securities Held	The following table summarizes the marketable securities held at December 31, 2023 and 2022 (in thousands): Amortized cost / cost Unrealized gains Unrealized losses Fair value December 31, 2023 U.S. government agency securities and treasuries $ — $ — $ — $ — Total $ — $ — $ — $ — December 31, 2022 U.S. government agency securities and treasuries $ 67,970 $ — $ (1,733) $ 66,237 Corporate bonds 2,524 — (26) 2,498 Total $ 70,494 $ — $ (1,759) $ 68,735

Fair value measurements (Tables

Fair value measurements (Tables)	12 Months Ended
	Dec. 31, 2023
Fair Value Disclosures [Abstract]
Recorded Amount of Assets and Liabilities Measured at Fair Value on Recurring Basis	The following table sets forth the Company’s assets and liabilities that are measured at fair value on a recurring basis as of December 31, 2023 and 2022 (in thousands): Total Quoted Significant Significant December 31, 2023 Assets: Cash and cash equivalents $ 221,755 $ 221,755 $ — $ — Marketable securities: U.S. government agency securities and treasuries — — — — Receivables and other current assets: Beneficiary interest in factored invoices 560 — — 560 Total assets $ 222,315 $ 221,755 $ — $ 560 December 31, 2022 Assets: Cash and cash equivalents $ 113,006 $ 113,006 $ — $ — Marketable securities: U.S. government agency securities and treasuries 66,237 — 66,237 — Corporate bonds 2,498 — 2,498 — Total assets $ 181,741 $ 113,006 $ 68,735 $ —
Debt Securities, Available-for-sale, Unrealized Loss Position, Fair Value	The following table summarizes available-for-sale debt securities in a continuous unrealized loss position for less than and greater than twelve months, and for which an allowance for credit losses has not been recorded at December 31, 2023 and 2022 (in thousands): Less than 12 months 12 months or greater Total Description Fair value Unrealized losses Fair value Unrealized losses Fair value Unrealized losses December 31, 2023 U.S. government agency securities $ — $ — $ — $ — $ — $ — Total $ — $ — $ — $ — $ — $ — December 31, 2022 U.S. government agency securities $ — $ — $ 66,237 $ (1,733) $ 66,237 $ (1,733) Corporate bonds — — 2,498 (26) 2,498 (26) Total $ — $ — $ 68,735 $ (1,759) $ 68,735 $ (1,759)
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation	The following table shows a reconciliation of the beginning and ending balances for Level 3 financial liabilities measured at fair value on a recurring basis for the three months ended December 31, 2023: For the year ended December 31, 2023 Level 3 financial assets, beginning of period $ — Beneficiary interest obtained in transferred invoices 560 Proceeds from previously transferred invoices — Level 3 financial assets, end of period $ 560

Inventory (Tables)

Inventory (Tables)	12 Months Ended
	Dec. 31, 2023
Inventory Disclosure [Abstract]
Schedule of Inventory	Inventory, net, consists of the following (in thousands): As of December 31, 2023 2022 Raw materials $ 2,329 $ — Work in progress 17,375 — Finished goods 3,215 — Inventory $ 22,919 $ —

Property, plant and equipment_2

Property, plant and equipment, net (Tables)	12 Months Ended
	Dec. 31, 2023
Property, Plant and Equipment [Abstract]
Summary of Property, Plant and Equipment Net	Property, plant and equipment, net, consists of the following (in thousands): As of December 31, 2023 2022 (As Restated) Finance lease right of use assets $ 84,524 $ 71,179 Laboratory equipment 14,636 21,048 Office equipment 4,767 4,323 Computer equipment and software 2,005 1,597 Leasehold improvements 1,251 — Construction-in-progress 563 — Total property, plant and equipment 107,746 98,147 Less accumulated depreciation and amortization (41,810) (30,511) Property, plant and equipment, net $ 65,936 $ 67,636

Restricted cash (Tables)

Restricted cash (Tables)	12 Months Ended
	Dec. 31, 2023
Other Assets, Noncurrent [Abstract]
Schedule of collateralized bank account of financial institution	Total restricted cash as of December 31, 2023 and 2022 consisted of the following (in thousands): As of December 31, 2023 2022 50 Binney Street lease $ 40,072 $ 40,072 Assembly Row lease 2,753 2,753 Embedded lease 7,632 — Other 2,385 2,614 Total restricted cash $ 52,842 $ 45,439

Accrued expenses and other cu_2

Accrued expenses and other current liabilities (Tables)	12 Months Ended
	Dec. 31, 2023
Payables and Accruals [Abstract]
Summary of accrued expenses and other current liabilities	Accrued expenses and other current liabilities consist of the following (in thousands): As of December 31, 2023 2022 (As Restated) Accrued CMO and CRO costs $ 24,824 $ 17,369 Accrued employee compensation 19,972 20,095 Accrued goods and services 8,391 7,635 Accrued rebates 5,365 — Accrued refund liability 5,600 — Other 9,036 8,365 Total accrued expenses and other current liabilities $ 73,188 $ 53,464

Leases (Tables)

Leases (Tables)	12 Months Ended
	Dec. 31, 2023
Leases [Abstract]
Lease, Cost	The following table contains a summary of the lease costs recognized under ASC 842 and other information pertaining to the Company’s operating and finance leases for the years ended December 31, 2023 and 2022 (in thousands): For the year ended December 31, 2023 2022 (As Restated) Finance leases Interest expense $ 16,350 $ 6,324 Amortization expense 24,653 3,886 Total fixed finance lease cost $ 41,003 $ 10,210 Operating leases Fixed lease cost 43,272 36,122 Total fixed operating lease cost 43,272 36,122 Variable lease cost 22,960 28,161 Short-term lease cost 238 143 Total lease cost $ 107,473 $ 74,636 Operating sublease income $ 41,165 $ 29,369 Cash paid in the measurement of lease liabilities Operating cash flows used for operating leases $ 28,887 $ 14,072 Operating cash flows used for finance leases 12,924 1,551 Financing cash flows for finance leases 54,367 36,734 Other information Weighted average remaining lease term - finance leases (in years) 1.6 years 2.4 years Weighted average discount rate - finance leases 13.93 % 12.52 % Weighted average remaining lease term - operating leases (in years) 7.0 years 7.8 years Weighted average discount rate - operating leases 7.01 % 7.05 %
Future Minimum Commitments	As of December 31, 2023, future minimum commitments under ASC 842 under the Company’s leases were as follows (in thousands): Operating Leases Financing Leases Remaining Lease Payments 2024 34,918 93,531 2025 37,084 34,995 2026 35,719 2,519 2027 36,742 2,519 2028 37,795 1,031 2029 and thereafter 81,986 — Total 264,244 134,595 Less: Imputed Interest (56,355) (12,158) Present Value of Lease Liabilities $ 207,889 $ 122,437
Future Minimum Commitments	As of December 31, 2023, future minimum commitments under ASC 842 under the Company’s leases were as follows (in thousands): Operating Leases Financing Leases Remaining Lease Payments 2024 34,918 93,531 2025 37,084 34,995 2026 35,719 2,519 2027 36,742 2,519 2028 37,795 1,031 2029 and thereafter 81,986 — Total 264,244 134,595 Less: Imputed Interest (56,355) (12,158) Present Value of Lease Liabilities $ 207,889 $ 122,437

Commitments and contingencies (

Commitments and contingencies (Tables)	12 Months Ended
	Dec. 31, 2023
Commitments and Contingencies Disclosure [Abstract]
Schedule of Non-cancelable Contractual Obligations	The following table presents the non-cancelable contractual obligations arising from this arrangement (in thousands): Years ended December 31, Future commitment 2024 $ — 2025 11,959 2026 17,655 2027 17,655 2028 7,225 2029 and thereafter — Total purchase commitments $ 54,494

Intangible assets (Tables)

Intangible assets (Tables)	12 Months Ended
	Dec. 31, 2023
Goodwill and Intangible Assets Disclosure [Abstract]
Schedule of Finite-Lived Intangible Assets	Intangible assets, net of accumulated amortization, are summarized as follows (in thousands): As of December 31, 2023 Cost Accumulated amortization Impairment Net In-licensed rights 11,089 (651) — 10,438 Total $ 11,089 $ (651) $ — $ 10,438 As of December 31, 2022 Cost Accumulated amortization Impairment Net In-licensed rights 5,000 (132) — 4,868 Total $ 5,000 $ (132) $ — $ 4,868
Schedule of Finite-Lived Intangible Assets, Future Amortization Expense	The following table summarizes the estimated future amortization for intangible assets for the next five years and thereafter (in thousands): As of December 31, 2023 2024 $ 926 2025 926 2026 926 2027 926 2028 926 2029 and thereafter $ 5,808 Total $ 10,438

Stock-based compensation (Table

Stock-based compensation (Tables)	12 Months Ended
	Dec. 31, 2023
Share-Based Payment Arrangement [Abstract]
Summary of Stock-Based Compensation Expense by Award Type	Stock-based compensation expense recognized by award type is as follows (in thousands): Year ended December 31, 2023 2022 (As Restated) Stock options $ 6,478 $ 14,168 Restricted stock units 12,619 20,138 Employee stock purchase plan and other 332 784 $ 19,429 $ 35,090
Schedule of Stock-Based Compensation Expense by Classification	Stock-based compensation expense by classification included within the consolidated statements of operations and comprehensive loss was as follows (in thousands): Year ended December 31, 2023 2022 (As Restated) Cost of product revenue $ 881 $ — Selling, general and administrative 9,548 15,831 Research and development 9,000 19,259 $ 19,429 $ 35,090
Assumptions Used for the Black-Scholes Option-Pricing Model to Determine the Per Share Weighted Average Fair Value for Options Granted	The fair value of each option issued to employees was estimated at the date of grant using the Black-Scholes option pricing model with the following weighted-average assumptions: Year ended December 31, 2023 2022 Expected volatility 70.9 % 66.4 % Expected term (in years) 6.10 6.0 Risk-free interest rate 4.1 % 1.9 % Expected dividend yield 0.0 % 0.0 %
Summary of Stock Option Activity Under Plan	The following table summarizes the stock option activity under the Company’s equity awards plans excluding awards held by employees of 2seventy bio: Shares Weighted- Weighted- Aggregate Outstanding at December 31, 2022 2,668 $ 24.38 Granted 2,077 $ 4.89 Exercised (3) $ 2.74 Canceled or forfeited (515) $ 29.55 Outstanding at December 31, 2023 4,227 $ 14.16 8.06 $ — Exercisable at December 31, 2023 1,469 $ 28.80 6.54 $ — Vested and expected to vest at December 31, 2023 4,227 $ 14.16 8.06 $ — (a)
Summary of Restricted Common Stock Awards	The following table summarizes the restricted stock unit activity under the Company’s equity award plans excluding awards held by employees of 2seventy bio: Shares Weighted-average Unvested balance at December 31, 2022 2,415 $ 11.44 Granted 3,369 4.76 Vested (1,057) 14.35 Forfeited (520) 8.09 Unvested balance at December 31, 2023 4,207 $ 6.08

Income taxes (Tables)

Income taxes (Tables)	12 Months Ended
	Dec. 31, 2023
Income Tax Disclosure [Abstract]
Schedule Components of Loss Before Income Taxes	The components of loss before income taxes were as follows (in thousands): Year ended December 31, 2023 2022 (As Restated) U.S. $ (213,306) $ (230,160) Foreign 1,267 (65) Total $ (212,039) $ (230,225)
Summary of Provision for (Benefit from) Income Taxes	The provision for (benefit from) income taxes were as follows (in thousands): Year ended December 31, 2023 2022 (As Restated) Current: Federal $ — $ — State — — Foreign (126) 117 Deferred: Federal — — State — — Foreign — — Total income tax expense (benefit) $ (126) $ 117
Reconciliation of Income Tax Provision (Benefit) Computed at the Statutory Federal Income Tax Rate to Effective Income Tax Rate (Provision) Benefit as Reflected in the Financial Statements	A reconciliation of income tax expense (benefit) computed at the statutory federal income tax rate to the Company’s effective income tax rate as reflected in the financial statements is as follows: Year ended December 31, 2023 2022 (As Restated) Federal income tax expense at statutory rate 21.0 % 21.0 % State income tax, net of federal benefit 7.3 % 5.2 % Permanent differences 0.6 % (0.1) % Stock-based compensation (3.6) % (9.3) % Research and development credit 5.8 % 8.3 % Leases 5.4 % 34.4 % Right-of-use assets — % (26.1) % Fixed assets (2.7) % (7.2) % Foreign differential — % 0.3 % Other 0.9 % (0.6) % Change in valuation allowance (34.6) % (26.0) % Effective income tax rate (expense) benefit 0.1 % (0.1) %
Components of Deferred Tax Assets and Liabilities	The significant components of the Company’s deferred tax assets and liabilities are composed of the following (in thousands): Year ended December 31, 2023 2022 (As Restated) Deferred tax assets: U.S. net operating loss carryforwards (federal and state) $ 726,021 $ 713,557 Tax credit carryforwards (federal and state) 313,963 300,236 Capitalized license fees and research and development expenses 2,079 1,831 Capitalized research and development expenses under Section 174 91,306 54,885 Stock-based compensation 9,847 11,686 Lease liabilities 100,288 98,296 Accruals and other 20,336 17,325 Total deferred tax assets 1,263,840 1,197,816 Right-of-use assets (54,976) (61,388) Fixed assets (16,701) (17,536) Less valuation allowance (1,192,163) (1,118,892) Net deferred taxes $ — $ —
Reconciliation of Unrecognized Tax Benefits	A reconciliation of the beginning and ending amount of unrecognized tax benefits is as follows (in thousands): Unrecognized tax benefits Balance as of December 31, 2021 (As Restated) $ 21,956 Increases (decreases) for tax positions related to current period 1,582 Increases (decreases) for tax positions related to prior periods (45) Balance as of December 31, 2022 (As Restated) 23,493 Increases (decreases) for tax positions related to current period 944 Increases (decreases) for tax positions related to prior periods 101 Balance as of December 31, 2023 24,538

Reduction in workforce (Tables)

Reduction in workforce (Tables)	12 Months Ended
	Dec. 31, 2023
Restructuring and Related Activities [Abstract]
Restructuring and Related Costs	The following tables summarizes the accrued liabilities activity recorded in connection with the reduction in workforce for the year ended December 31, 2022 (in thousands): Restructuring Expenses in 2022 Amounts paid in 2022 April 2022 reduction 4,940 (4,940) Total 4,940 (4,940)

Net loss per share (Tables)

Net loss per share (Tables)	12 Months Ended
	Dec. 31, 2023
Earnings Per Share [Abstract]
Common Stock Equivalents Excluded from Calculation of Diluted 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): Year ended December 31, 2023 2022 Outstanding stock options (1) 5,860 4,429 Restricted stock units (1) 4,239 2,524 Warrants 12,450 — ESPP shares and other 90 63 22,639 7,016 (1) Outstanding stock options and restricted stock units include awards outstanding to employees of 2seventy bio.

Quarterly Financial Informati_2

Quarterly Financial Information (Unaudited) (Tables)	12 Months Ended
	Dec. 31, 2023
Quarterly Financial Information Disclosure [Abstract]
Schedule of Error Corrections and Prior Period Adjustments	The following tables represent the as-restated consolidated balance sheet as of December 31, 2022, and the related consolidated statements of operations and comprehensive loss, stockholders’ equity and cash flows for the year ended December 31, 2022. These tables also present a reconciliation from the prior period as previously reported to the as-restated amounts. The amounts as previously reported for fiscal year 2022 were derived from the Annual Report on Form 10-K for the fiscal year ended December 31, 2022, filed on March 29, 2023. Consolidated Balance Sheet: As of December 31, 2022 (in thousands) As Previously Reported Adjustments to Leases Other Adjustments As Restated Assets Current assets: Cash and cash equivalents $ 113,006 $ — $ — $ 113,006 Marketable securities 67,321 — — 67,321 Prepaid expenses 8,374 244 — 8,618 Receivables and other current assets 10,787 3,840 — 14,627 Total current assets 199,488 4,084 — 203,572 Marketable securities 1,414 — — 1,414 Property, plant and equipment, net 9,362 58,585 (311) 67,636 Goodwill 5,646 — — 5,646 Intangible assets, net 4,868 — — 4,868 Operating lease right-of-use assets 281,996 (51,111) 230,885 Restricted cash and other non-current assets 52,128 3,665 — 55,793 Total assets $ 554,902 $ 15,223 $ (311) $ 569,814 Liabilities and Stockholders’ Equity Current Liabilities: Accounts payable $ 25,092 $ (10,225) $ — $ 14,867 Accrued expenses and other current liabilities 51,985 (520) 1,999 53,464 Operating lease liability, current portion 51,160 (23,566) — 27,594 Finance lease liability, current portion — 60,654 — 60,654 Total current liabilities 128,237 26,343 1,999 156,579 Operating lease liability, net of current portion 230,230 (21,102) — 209,128 Financing lease liability, net of current portion — 69,682 — 69,682 Other non-current liabilities 92 — — 92 Total liabilities 358,559 74,923 1,999 435,481 Commitments and contingencies (Note 12) Stockholders’ Equity: Preferred stock, $0.01 par value, 5,000 shares authorized; 0 shares issued and outstanding at December 31, 2022 $ — $ — $ — $ — Common stock, $0.01 par value, 125,000 shares authorized; 82,923 shares issued and outstanding at December 31, 2022 830 — — 830 Additional paid-in capital 4,186,086 — (98) 4,185,988 Accumulated other comprehensive loss (4,070) — — (4,070) Accumulated deficit (3,986,503) (59,700) (2,212) (4,048,415) Total stockholders’ equity 196,343 (59,700) (2,310) 134,333 Total liabilities and stockholders’ equity $ 554,902 $ 15,223 $ (311) $ 569,814 Consolidated Statement of Operations and Comprehensive Loss Year ended December 31, 2022 (in thousands, except per share amounts) As Previously Reported Adjustments to Leases Other Adjustments As Restated Revenue: Product revenue, net $ 2,739 $ — $ — $ 2,739 Other revenue 858 — — 858 Total revenues 3,597 — — 3,597 Cost of product revenue 10,077 — — 10,077 Gross margin (6,480) — — (6,480) Operating expenses: Research and development 240,764 (40,121) (204) 200,439 Selling, general and administrative 136,908 3,516 (98) 140,326 Restructuring expenses 4,940 — — 4,940 Total operating expenses 382,612 (36,605) (302) 345,705 Gain from sale of priority review voucher, net 102,000 — — 102,000 (Loss) Income from operations (287,092) 36,605 302 (250,185) Interest income 1,032 — — 1,032 Interest expense — (6,322) — (6,322) Other (expense) income, net 19,599 5,651 — 25,250 (Loss) income before income taxes (266,461) 35,934 302 (230,225) Income tax (expense) benefit (117) — — (117) Net (loss) income (266,578) 35,934 302 (230,342) Net (loss) income per share - basic $ (3.39) $ 0.46 $ — $ (2.93) Net (loss) income per share - diluted $ (3.39) $ 0.46 $ — $ (2.93) Weighted-average number of common shares used in computing net (loss) income per share - basic: 78,585 — — 78,585 Weighted-average number of common shares used in computing net (loss) income per share - diluted: 78,585 — — 78,585 Other comprehensive (loss) income: Other comprehensive (loss) income, net of tax (benefit) expense of $0.0 million for the year ended December 31, 2022 (1,159) — — (1,159) Total other comprehensive (loss) income (1,159) — — (1,159) Comprehensive (loss) income $ (267,737) $ 35,934 $ 302 $ (231,501) Consolidated Statement of Changes in Stockholders' Equity: Common stock Additional Accumulated Accumulated Total (in thousands) Shares Amount As Previously Reported Balances at December 31, 2021 71,115 $ 711 $ 4,096,402 $ (2,911) $ (3,719,925) $ 374,277 Vesting of restricted stock 979 10 (10) — — — Exercise of stock options 7 — 16 — — 16 Purchase of shares under ESPP 68 1 238 — — 239 Issuance of common stock 10,742 107 53,960 — — 54,067 Issuance of unrestricted stock awards to settle accrued employee compensation 12 1 — — — 1 Stock-based compensation expense — — 35,480 — — 35,480 Other comprehensive loss — — — (1,159) — (1,159) Net (loss) income — — — — (266,578) (266,578) Balances at December 31, 2022 82,923 $ 830 $ 4,186,086 $ (4,070) $ (3,986,503) $ 196,343 Adjustments to Leases Balances at December 31, 2021 — $ — $ — $ — $ (95,634) $ (95,634) Vesting of restricted stock — — — — — — Exercise of stock options — — — — — — Purchase of shares under ESPP — — — — — — Issuance of common stock — — — — — — Issuance of unrestricted stock awards to settle accrued employee compensation — — — — — — Stock-based compensation expense — — — — — — Other comprehensive loss — — — — — — Net (loss) income — — — — 35,934 35,934 Balances at December 31, 2022 — $ — $ — $ — $ (59,700) $ (59,700) Other Adjustments Balances at December 31, 2021 — — — — (2,514) (2,514) Vesting of restricted stock — — — — — — Exercise of stock options — — — — — — Purchase of shares under ESPP — — — — — — Issuance of common stock — — — — — — Issuance of unrestricted stock awards to settle accrued employee compensation — — — — — — Stock-based compensation expense — — (98) — — (98) Other comprehensive loss — — — — — — Net (loss) income — — — — 302 302 Balances at December 31, 2022 — $ — $ (98) $ — $ (2,212) $ (2,310) As Restated Balances at December 31, 2021 71,115 711 4,096,402 (2,911) (3,818,073) 276,129 Vesting of restricted stock 979 10 (10) — — — Exercise of stock options 7 — 16 — — 16 Purchase of shares under ESPP 68 1 238 — — 239 Issuance of common stock 10,742 107 53,960 — — 54,067 Issuance of unrestricted stock awards to settle accrued employee compensation 12 1 — — — 1 Stock-based compensation expense — — 35,382 — — 35,382 Other comprehensive loss — — — (1,159) — (1,159) Net (loss) income — — — — (230,342) (230,342) Balances at December 31, 2022 82,923 $ 830 $ 4,185,988 $ (4,070) $ (4,048,415) $ 134,333 Consolidated Statement of Cash Flows Year Ended December 31, 2022 (in thousands) As Previously Reported Adjustments to Leases Other Adjustments As Restated Cash flows from operating activities: Net (loss) income $ (266,578) $ 35,934 $ 302 $ (230,342) Adjustments to reconcile net loss to net cash used in operating activities: Depreciation and amortization 5,001 3,547 (204) 8,344 Stock-based compensation expense 35,188 — (98) 35,090 Noncash research and development expense (finance lease) — 11,180 — 11,180 Noncash operating lease expense — 23,562 — 23,562 Gain from sale of priority review voucher (102,000) — — (102,000) Unrealized loss on equity securities 3,135 — — 3,135 Excess inventory reserve 7,519 — — 7,519 Other non-cash items 3,904 234 — 4,138 (Gain) on foreign currency exchange rates — (1,801) — (1,801) Changes in operating assets and liabilities: Prepaid expenses and other assets 3,260 (8,080) — (4,820) Inventory (7,227) — — (7,227) Operating right of use assets 42,706 (42,706) — — Accounts payable (920) (6,789) — (7,709) Accrued expenses and other liabilities (51,228) 5,254 — (45,974) Accrued interest payable under finance lease — 4,758 — 4,758 Operating lease liabilities (25,713) 11,641 — (14,072) Net cash used in operating activities (352,953) 36,734 — (316,219) Cash flows from investing activities: Purchase of property, plant and equipment (8,208) — — (8,208) Proceeds from maturities of marketable securities 131,445 — — 131,445 Proceeds from sales of marketable securities 30,216 — — 30,216 Purchase of intangible assets (5,000) — — (5,000) Proceeds from sale of priority review voucher 102,000 — — 102,000 Net cash provided by investing activities 250,453 — — 250,453 Cash flows from financing activities: Proceeds from exercise of stock options and ESPP contributions 16 — — 16 Principal payments on finance lease — (36,734) — (36,734) Proceeds from public offering of common stock, net of issuance costs 54,237 — — 54,237 Net cash provided by financing activities 54,253 (36,734) — 17,519 (Decrease) increase in cash, cash equivalents and restricted cash (48,247) — — (48,247) Cash, cash equivalents and restricted cash at beginning of year 206,692 — — 206,692 Cash, cash equivalents and restricted cash at end of year $ 158,445 $ — $ — $ 158,445 Reconciliation of cash, cash equivalents and restricted cash: Cash and cash equivalents $ 113,006 $ — $ — $ 113,006 Restricted cash included in receivables and other current assets 1,502 — — 1,502 Restricted cash included in restricted cash and other non-current assets 43,937 — — 43,937 Total cash, cash equivalents and restricted cash $ 158,445 $ — $ — $ 158,445 Supplemental cash flow disclosures: Right-of-use assets obtained in exchange for operating lease liabilities 236,003 (14,967) — 221,036 Increase (Reduction) of right of use asset and associated operating lease liability due to lease reassessment (2,833) 2,833 — — Purchases of property, plant and equipment included in accounts (3) — — (3) Offering expenses included in accounts payable and accrued expenses 170 — — 170 Right-of-use assets obtained in exchange for finance lease liabilities — 73,443 — 73,443 Cash paid during the period for income taxes 253 — — 253 The following unaudited condensed consolidated balance sheet tables present the impacts of the restatement adjustments as of the periods ended March 31, 2023 and 2022, June 30, 2023 and 2022, and September 30, 2023 and 2022. The period ended December 31, 2023 was not subject to restatement. As of March 31, 2023 (in thousands) As Previously Reported Adjustments to Leases Other Adjustments As Restated Assets Current assets: Cash and cash equivalents $ 239,045 $ — $ — $ 239,045 Marketable securities 79,212 — — 79,212 Prepaid expenses 13,466 (2,082) — 11,384 Inventory 3,809 (610) — 3,199 Receivables and other current assets 15,539 3,374 (2,800) 16,113 Total current assets 351,071 682 (2,800) 348,953 Property, plant and equipment, net 8,718 53,223 (270) 61,671 Goodwill 5,646 — — 5,646 Intangible assets, net 5,613 — — 5,613 Operating lease right-of-use assets 270,153 (46,690) — 223,463 Restricted cash and other non-current assets 51,535 3,665 — 55,200 Total assets $ 692,736 $ 10,880 $ (3,070) $ 700,546 Liabilities and Stockholders’ Equity Current Liabilities: Accounts payable $ 19,235 $ (2,522) $ — $ 16,713 Accrued expenses and other current liabilities 45,294 1,017 (801) 45,510 Operating lease liability, current portion 51,404 (24,784) 26,620 Financing lease liability, current portion — 58,747 — 58,747 Total current liabilities 115,933 32,458 (801) 147,590 Operating lease liability, net of current portion 221,971 (18,176) 203,795 Financing lease liability, net of current portion — 58,649 — 58,649 Other non-current liabilities 92 — — 92 Total liabilities 337,996 72,931 (801) 410,126 Commitments and contingencies (Note 12) Stockholders’ Equity: Preferred stock, $0.01 par value, 5,000 shares authorized; 0 shares issued and outstanding at March 31, 2023 $ — $ — $ — $ — Common stock, $0.01 par value, 125,000 shares authorized; 106,370 shares issued and outstanding at March 31, 2023 1,064 — — 1,064 Additional paid-in capital 4,322,025 — (98) 4,321,927 Accumulated other comprehensive loss (3,086) — — (3,086) Accumulated deficit (3,965,263) (62,051) (2,171) (4,029,485) Total stockholders’ equity 354,740 (62,051) (2,269) 290,420 Total liabilities and stockholders’ equity $ 692,736 $ 10,880 $ (3,070) $ 700,546 As of June 30, 2023 (in thousands) As Previously Reported Adjustments to Leases Other Adjustments As Restated Assets Current assets: Cash and cash equivalents $ 172,872 $ — $ — $ 172,872 Marketable securities 72,431 — — 72,431 Prepaid expenses 13,597 (2,162) — 11,435 Inventory 13,642 (1,838) 602 12,406 Receivables and other current assets 15,435 3,659 19,094 Total current assets 287,977 (341) 602 288,238 Property, plant and equipment, net 10,227 51,722 (235) 61,714 Goodwill 5,646 — — 5,646 Intangible assets, net 5,490 — — 5,490 Operating lease right-of-use assets 302,849 (86,929) 215,920 Restricted cash and other non-current assets 51,204 3,665 — 54,869 Total assets $ 663,393 $ (31,883) $ 367 $ 631,877 Liabilities and Stockholders’ Equity Current Liabilities: Accounts payable $ 10,894 $ (1,081) $ — $ 9,813 Accrued expenses and other current liabilities 56,531 (599) 1,999 57,931 Operating lease liability, current portion 67,591 (42,427) — 25,164 Financing lease liability, current portion — 55,706 — 55,706 Total current liabilities 135,016 11,599 1,999 148,614 Operating lease liability, net of current portion 239,266 (40,930) 198,336 Financing lease liability, net of current portion — 50,017 — 50,017 Other non-current liabilities 92 — — 92 Total liabilities 374,374 20,686 1,999 397,059 Commitments and contingencies (Note 12) Stockholders’ Equity: Preferred stock, $0.01 par value, 5,000 shares authorized; 0 shares issued and outstanding at June 30, 2023 $ — $ — $ — $ — Common stock, $0.01 par value, 250,000 shares authorized; 106,454 shares issued and outstanding at June 30, 2023 1,065 — — 1,065 Additional paid-in capital 4,328,489 — (98) 4,328,391 Accumulated other comprehensive loss (2,364) — — (2,364) Accumulated deficit (4,038,171) (52,569) (1,534) (4,092,274) Total stockholders’ equity 289,019 (52,569) (1,632) 234,818 Total liabilities and stockholders’ equity $ 663,393 $ (31,883) $ 367 $ 631,877 As of September 30, 2023 (in thousands) As Previously Reported Adjustments to Leases Other Adjustments As Restated Assets Current assets: Cash and cash equivalents $ 165,347 $ — $ — $ 165,347 Marketable securities 8,946 — — 8,946 Accounts Receivable 23,000 — (8,400) 14,600 Prepaid expenses 11,431 (2,040) — 9,391 Inventory 20,969 (3,205) 602 18,366 Other current assets 17,383 3,538 20,921 Total current assets 247,076 (1,707) (7,798) 237,571 Property, plant and equipment, net 9,972 63,398 (280) 73,090 Goodwill 5,646 — — 5,646 Intangible assets, net 5,368 — — 5,368 Operating lease right-of-use assets 294,717 (87,796) 206,921 Restricted cash and other non-current assets 50,829 3,665 — 54,494 Total assets $ 613,608 $ (22,440) $ (8,078) $ 583,090 Liabilities and Stockholders’ Equity Current Liabilities: Accounts payable $ 19,852 $ (3,042) $ 316 $ 17,126 Deferred revenue 9,653 — (8,400) 1,253 Accrued expenses and other current liabilities 57,768 572 — 58,340 Operating lease liability, current portion 71,684 (46,160) — 25,524 Financing lease liability, current portion — 85,208 — 85,208 Total current liabilities 158,957 36,578 (8,084) 187,451 Operating lease liability, net of current portion 232,023 (39,456) — 192,567 Financing lease liability, net of current portion — 50,146 — 50,146 Other non-current liabilities 92 — — 92 Total liabilities 391,072 47,268 (8,084) 430,256 Commitments and contingencies (Note 12) Stockholders’ Equity: Preferred stock, $0.01 par value, 5,000 shares authorized; 0 shares issued and outstanding at September 30, 2023 $ — $ — $ — $ — Common stock, $0.01 par value, 250,000 shares authorized; 107,022 shares issued and outstanding at September 30, 2023 1,071 — — 1,071 Additional paid-in capital 4,333,594 — (98) 4,333,496 Accumulated other comprehensive loss (2,227) — — (2,227) Accumulated deficit (4,109,902) (69,708) 104 (4,179,506) Total stockholders’ equity 222,536 (69,708) 6 152,834 Total liabilities and stockholders’ equity $ 613,608 $ (22,440) $ (8,078) $ 583,090 As of March 31, 2022 (in thousands) As Previously Reported Adjustments to Leases Other Adjustments As Restated Assets Current assets: Cash and cash equivalents $ 106,260 $ — $ — $ 106,260 Marketable securities 105,328 — — 105,328 Prepaid expenses 31,798 (1,549) — 30,249 Receivables and other current assets 11,531 198 — 11,729 Total current assets 254,917 (1,351) — 253,566 Marketable securities 55,049 — — 55,049 Property, plant and equipment, net 11,234 (599) (459) 10,176 Goodwill 5,646 — — 5,646 Operating lease right-of-use assets 111,897 (61,082) — 50,815 Restricted cash and other non-current assets 52,328 3,665 — 55,993 Total assets $ 491,071 $ (59,367) $ (459) $ 431,245 Liabilities and Stockholders’ Equity Current Liabilities: Accounts payable $ 28,350 $ (4,937) $ — $ 23,413 Accrued expenses and other current liabilities 89,032 (15,597) 1,999 75,434 Operating lease liability, current portion 25,510 (9,262) — 16,248 Financing lease liability, current portion — 55,995 — 55,995 Total current liabilities 142,892 26,199 1,999 171,090 Operating lease liability, net of current portion 84,828 (46,407) — 38,421 Financing lease liability, net of current portion — 41,315 — 41,315 Other non-current liabilities 92 — — 92 Total liabilities 227,812 21,107 1,999 250,918 Commitments and contingencies (Note 12) Stockholders’ Equity: Preferred stock, $0.01 par value, 5,000 shares authorized; 0 shares issued and outstanding at March 31, 2022 $ — $ — $ — $ — Common stock, $0.01 par value, 125,000 shares authorized; 71,438 shares issued and outstanding at March 31, 2022 714 — — 714 Additional paid-in capital 4,109,081 — (1,384) 4,107,697 Accumulated other comprehensive loss (4,459) — — (4,459) Accumulated deficit (3,842,077) (80,474) (1,074) (3,923,625) Total stockholders’ equity 263,259 (80,474) (2,458) 180,327 Total liabilities and stockholders’ equity $ 491,071 $ (59,367) $ (459) $ 431,245 As of June 30, 2022 (in thousands) As Previously Reported Adjustments to Leases Other Adjustments As Restated Assets Current assets: Cash and cash equivalents $ 81,499 $ — $ — $ 81,499 Marketable securities 51,010 — — 51,010 Prepaid expenses 24,473 (667) — 23,806 Receivables and other current assets 10,476 2,997 — 13,473 Total current assets 167,458 2,330 — 169,788 Marketable securities 40,641 — — 40,641 Property, plant and equipment, net 14,566 (688) (406) 13,472 Goodwill 5,646 — — 5,646 Operating lease right-of-use assets 292,731 (54,005) — 238,726 Restricted cash and other non-current assets 52,550 3,665 — 56,215 Total assets $ 573,592 $ (48,698) $ (406) $ 524,488 Liabilities and Stockholders’ Equity Current Liabilities: Accounts payable $ 24,865 $ (2,846) $ — $ 22,019 Accrued expenses and other current liabilities 75,550 (12,189) 1,999 65,360 Operating lease liability, current portion 48,446 (22,583) — 25,863 Financing lease liability, current portion — 47,219 — 47,219 Total current liabilities 148,861 9,601 1,999 160,461 Operating lease liability, net of current portion 244,522 (27,634) — 216,888 Financing lease liability, net of current portion — 36,550 — 36,550 Other non-current liabilities 93 — — 93 Total liabilities 393,476 18,517 1,999 413,992 Commitments and contingencies (Note 12) Stockholders’ Equity: Preferred stock, $0.01 par value, 5,000 shares authorized; 0 shares issued and outstanding at June 30, 2022 $ — $ — $ — $ — Common stock, $0.01 par value, 125,000 shares authorized; 73,551 shares issued and outstanding at June 30, 2022 735 — — 735 Additional paid-in capital 4,126,012 — (1,854) 4,124,158 Accumulated other comprehensive loss (4,416) — — (4,416) Accumulated deficit (3,942,215) (67,215) (551) (4,009,981) Total stockholders’ equity 180,116 (67,215) (2,405) 110,496 Total liabilities and stockholders’ equity $ 573,592 $ (48,698) $ (406) $ 524,488 As of September 30, 2022 (in thousands) As Previously Reported Adjustments to Leases Other Adjustments As Restated Assets Current assets: Cash and cash equivalents $ 66,478 $ — $ — $ 66,478 Marketable securities 73,155 — — 73,155 Prepaid expenses 8,270 55 — 8,325 Receivables and other current assets 12,535 2,425 — 14,960 Total current assets 160,438 2,480 — 162,918 Marketable securities 1,407 — — 1,407 Property, plant and equipment, net 11,535 (777) (358) 10,400 Goodwill 5,646 — — 5,646 Intangible assets, net — — 4,972 4,972 Operating lease right-of-use assets 288,684 (56,750) — 231,934 Restricted cash and other non-current assets 52,388 3,665 — 56,053 Total assets $ 520,098 $ (51,382) $ 4,614 $ 473,330 Liabilities and Stockholders’ Equity Current Liabilities: Accounts payable $ 18,622 $ (2,898) $ — $ 15,724 Accrued expenses and other current liabilities 64,314 (13,432) 1,998 52,880 Operating lease liability, current portion 43,791 (20,322) — 23,469 Financing lease liability, current portion — 41,264 — 41,264 Total current liabilities 126,727 4,612 1,998 133,337 Operating lease liability, net of current portion 234,422 (24,069) — 210,353 Financing lease liability, net of current portion — 31,036 — 31,036 Other non-current liabilities 92 — — 92 Total liabilities 361,241 11,579 1,998 374,818 Commitments and contingencies (Note 12) Stockholders’ Equity: Preferred stock, $0.01 par value, 5,000 shares authorized; 0 shares issued and outstanding at September 30, 2022 $ — $ — $ — $ — Common stock, $0.01 par value, 125,000 shares authorized; 82,880 shares issued and outstanding at September 30, 2022 829 — — 829 Additional paid-in capital 4,181,393 — (2,043) 4,179,350 Accumulated other comprehensive loss (4,630) — — (4,630) Accumulated deficit (4,018,735) (62,961) 4,659 (4,077,037) Total stockholders’ equity 158,857 (62,961) 2,616 98,512 Total liabilities and stockholders’ equity $ 520,098 $ (51,382) $ 4,614 $ 473,330 Condensed Consolidated Statements of Operations and Comprehensive Loss The following unaudited condensed consolidated statements of operations and comprehensive loss tables present the impacts of the restatement adjustments for the three months ended March 31, 2023 and 2022, the three and six months ended June 30, 2023 and 2022, and the three and nine months ended September 30, 2023 and 2022. The year ended December 31, 2023 was not subject to restatement. Three Months ended March 31, 2023 (in thousands, except per share amounts) As Previously Reported Adjustments to Leases Other Adjustments As Restated Revenue Product revenue $ 2,296 $ — $ — $ 2,296 Other revenue 85 — — 85 Total revenues 2,381 — — 2,381 Cost of product revenue 3,376 2,136 — 5,512 Gross margin (995) (2,136) — (3,131) Operating expenses: Selling, general and administrative 37,354 113 — 37,467 Research and development 46,144 (4,516) (41) 41,587 Total operating expenses 83,498 (4,403) (41) 79,054 Gain from sale of priority review voucher, net 92,930 — — 92,930 Income (loss) from operations 8,437 2,267 41 10,745 Interest income 2,828 — — 2,828 Interest expense (3) (4,267) — (4,270) Other income, net 9,978 (351) — 9,627 Income (loss) before income taxes 21,240 (2,351) 41 18,930 Income tax (expense) benefit — — — — Net income (loss) 21,240 (2,351) 41 18,930 Net income (loss) per share - basic (1) $ 0.21 $ (0.02) $ — $ 0.18 Net income (loss) per share - diluted (1) $ 0.21 $ (0.02) $ — $ 0.18 Weighted-average number of common shares used in computing net income (loss) per share - basic: 102,920 — — 102,920 Weighted-average number of common shares used in computing net income (loss) per share - diluted: 103,303 — — 103,303 Other comprehensive income (loss): Other comprehensive income (loss), net of tax (benefit) expense of $0.0 million for the three months ended March 31, 2023 984 — — 984 Total other comprehensive income (loss) 984 — — 984 Comprehensive income (loss) $ 22,224 $ (2,351) $ 41 $ 19,914 (1) Due to differences in rounding to the nearest cent per basic or diluted share, totals may not equal the sum of the line items. Six Months ended June 30, 2023 (in thousands, except per share amounts) As Previously Reported Adjustments to Leases Other Adjustments As Restated Revenue Product revenue $ 9,133 $ — $ — $ 9,133 Other revenue 138 — — 138 Total revenues 9,271 — — 9,271 Cost of product revenue 12,940 (731) — 12,209 Gross margin (3,669) 731 — (2,938) Operating expenses: Selling, general and administrative 77,703 226 — 77,929 Research and development 88,418 (14,705) (678) 73,035 Total operating expenses 166,121 (14,479) (678) 150,964 Gain from sale of priority review voucher, net 92,930 — — 92,930 Income (loss) from operations (76,860) 15,210 678 (60,972) Interest income 5,507 — — 5,507 Interest expense (3) (8,017) — (8,020) Other income, net 19,608 (62) — 19,546 Income (loss) before income taxes (51,748) 7,131 678 (43,939) Income tax (expense) benefit 80 — 80 Net income (loss) (51,668) 7,131 678 (43,859) Net income (loss) per share - basic $ (0.49) $ 0.07 $ 0.01 $ (0.41) Net income (loss) per share - diluted $ (0.49) $ 0.07 $ 0.01 $ (0.41) Weighted-average number of common shares used in computing net income (loss) per share - basic: 105,819 — — 105,819 Weighted-average number of common shares used in computing net income (loss) per share - diluted: 105,819 — — 105,819 Other comprehensive income (loss): Other comprehensive income (loss), net of tax (benefit) expense of $0.0 million for the six months ended June 30, 2023 1,706 — — 1,706 Total other comprehensive income (loss) 1,706 — — 1,706 Comprehensive income (loss) $ (49,962) $ 7,131 $ 678 $ (42,153) Three Months ended June 30, 2023 (in thousands, except per share amounts) As Previously Reported Adjustments to Leases Other Adjustments As Restated Revenue Product revenue $ 6,837 $ — $ — $ 6,837 Other revenue 53 — — 53 Total revenues 6,890 — — 6,890 Cost of product revenue 9,564 (2,867) — 6,697 Gross margin (2,674) 2,867 — 193 Operating expenses: — Selling, general and administrative 40,349 113 — 40,462 Research and development 42,274 (10,189) (637) 31,448 Total operating expenses 82,623 (10,076) (637) 71,910 Income (loss) from operations (85,297) 12,943 637 (71,717) Interest income 2,679 — — 2,679 Interest expense — (3,750) — (3,750) Other income, net 9,630 289 — 9,919 Income (loss) before income taxes (72,988) 9,482 637 (62,869) Income tax (expense) benefit 80 — — 80 Net income (loss) (72,908) 9,482 637 (62,789) Net income (loss) per share - basic (1) $ (0.67) $ 0.09 $ 0.01 $ (0.58) Net income (loss) per share - diluted (1) $ (0.67) $ 0.09 $ 0.01 $ (0.58) Weighted-average number of common shares used in computing net income (loss) per share - basic: 108,685 — — 108,685 Weighted-average number of common shares used in computing net income (loss) per share - diluted: 108,685 — — 108,685 Other comprehensive income (loss): Other comprehensive income (loss), net of tax (benefit) expense of $0.0 million for the three months ended June 30, 2023 722 — — 722 Total other comprehensive income (loss) 722 — — 722 Comprehensive income (loss) $ (72,186) $ 9,482 $ 637 $ (62,067) (1) Due to differences in rounding to the nearest cent per basic or diluted share, totals may not equal the sum of the line items. Nine Months ended September 30, 2023 (in thousands, except per share amounts) As Previously Reported Adjustments to Leases Other Adjustments As Restated Revenue Product revenue $ 21,414 $ — $ — $ 21,414 Other revenue 249 — — 249 Total revenues 21,663 — — 21,663 Cost of product revenue 23,895 (2,560) — 21,335 Gross margin (2,232) 2,560 — 328 Operating expenses: — Selling, general and administrative 118,406 294 — 118,700 Research and development 133,881 52 (2,397) 131,536 Total operating expenses 252,287 346 (2,397) 250,236 Gain from sale of priority review voucher, net 92,930 — — 92,930 Income (loss) from operations (161,589) 2,214 2,397 (156,978) Interest income 7,961 — — 7,961 Interest expense (3) (12,328) — (12,331) Other income (expense), net 30,152 106 (81) 30,177 Income (loss) before income taxes (123,479) (10,008) 2,316 (131,171) Income tax (expense) benefit 80 — — 80 Net income (loss) (123,399) (10,008) 2,316 (131,091) Net income (loss) per share - basic (1) $ (1.15) $ (0.09) $ 0.02 $ (1.23) Net income (loss) per share - diluted (1) $ (1.15) $ (0.09) $ 0.02 $ (1.23) Weighted-average number of common shares used in computing net income (loss) per share - basic: 106,924 — — 106,924 Weighted-average number of common shares used in computing net income (loss) per share - diluted: 106,924 — — 106,924 Other comprehensive income (loss): Other comprehensive income (loss), net of tax (benefit) expense of $0.0 million for the nine months ended September 30, 2023 1,843 — — 1,843 Total other comprehensive income (loss) 1,843 — — 1,843 Comprehensive income (loss) $ (121,556) $ (10,008) $ 2,316 $ (129,248) (1) Due to differences in rounding to the nearest cent per basic or diluted share, totals may not equal the sum of the line items. Three Months ended September 30, 2023 (in thousands, except per share amounts) As Previously Reported Adjustments to Leases Other Adjustments As Restated Revenue Product revenue $ 12,281 $ — $ — $ 12,281 Other revenue 111 — — 111 Total revenues 12,392 — — 12,392 Cost of product revenue 10,955 (1,829) — 9,126 Gross margin 1,437 1,829 — 3,266 Operating expenses: Selling, general and administrative 40,703 68 — 40,771 Research and development 45,463 14,757 (1,719) 58,501 Total operating expenses 86,166 14,825 (1,719) 99,272 Income (loss) from operations (84,729) (12,996) 1,719 (96,006) Interest income 2,454 — — 2,454 Interest expense — (4,311) — (4,311) Other income (expense), net 10,544 168 (81) 10,631 Income (loss) before income taxes (71,731) (17,139) 1,638 (87,232) Income tax (expense) benefit — — — — Net income (loss) (71,731) (17,139) 1,638 (87,232) Net income (loss) per share - basic $ (0.66) $ (0.16) $ 0.02 $ (0.80) Net income (loss) per share - diluted $ (0.66) $ (0.16) $ 0.02 $ (0.80) Weighted-average number of common shares used in computing net income (loss) per share - basic: 109,098 — — 109,098 Weighted-average number of common shares used in computing net income (loss) per share - diluted: 109,098 — — 109,098 Other comprehensive income (loss): Other comprehensive income (loss), net of tax (benefit) expense of $0.0 million for the three months ended September 30, 2023 137 — — 137 Total other comprehensive income (loss) 137 — — 137 Comprehensive income (loss) $ (71,594) $ (17,139) $ 1,638 $ (87,095) Three Months ended March 31, 2022 (in thousands, except per share amounts) As Previously Reported Adjustments to Leases Other Adjustments As Restated Revenue: Product revenue $ 1,408 $ — $ — $ 1,408 Other revenue 537 — — 537 Total revenues 1,945 — — 1,945 Cost of product revenue 8,310 — — 8,310 Gross margin (6,365) — — (6,365) Operating expenses: Research and development 77,875 (15,511) (930) 61,434 Selling, general and administrative 36,106 (147) (510) 35,449 Total operating expenses 113,981 (15,658) (1,440) 96,883 Income (loss) from operations (120,346) 15,658 1,440 (103,248) Interest income 106 — — 106 Interest expense — (1,028) — (1,028) Other income (expense), net (1,912) 530 — (1,382) Income (loss) before income taxes (122,152) 15,160 1,440 (105,552) Income tax (expense) benefit — — — — Net income (loss) (122,152) 15,160 1,440 (105,552) Net income (loss) per share - basic $ (1.66) $ 0.21 $ 0.02 $ (1.43) Net income (loss) per share - diluted $ (1.66) $ 0.21 $ 0.02 $ (1.43) Weighted-average number of common shares used in computing net income (loss) per share - basic: 73,688 — — 73,688 Weighted-average number of common shares used in computing net income (loss) per share - diluted: 73,688 — — 73,688 Other comprehensive income (loss): Other comprehensive income (loss), net of tax (benefit) expense of $0.0 million for the three months ended March 31, 2022 (1,548) — — (1,548) Total other comprehensive income (loss) (1,548) — — (1,548) Comprehensive income (loss) $ (123,700) $ 15,160 $ 1,440 $ (107,100) Six Months ended June 30, 2022 (in thousands, except per share amounts) As Previously Reported Adjustments to Leases Other Adjustments As Restated Revenue: Product revenue $ 2,739 $ — $ — $ 2,739 Other revenue 725 — — 725 Total revenues 3,464 — — 3,464 Cost of product revenue 10,055 — — 10,055 Gross margin (6,591) — — (6,591) Operating expenses: Research and development 141,716 (27,866) (1,192) 112,658 Selling, general and administrative 72,800 (461) (771) 71,568 Restructuring expenses 6,639 — — 6,639 Total operating expenses 221,155 (28,327) (1,963) 190,865 Income (loss) from operations (227,746) 28,327 1,963 (197,456) Interest income 280 — — 280 Interest expense — (1,950) — (1,950) Other income, net 5,176 2,042 — 7,218 Income (loss) before income taxes (222,290) 28,419 1,963 (191,908) Income tax (expense) benefit — — — — Net income (loss) (222,290) 28,419 1,963 (191,90

Description of the business - N

Description of the business - Narrative (Detail) $ in Thousands, shares in Millions

1 Months Ended

6 Months Ended

12 Months Ended

Mar. 15, 2024 USD ($) tranche

Dec. 22, 2023 USD ($)

Dec. 19, 2023 shares

Dec. 31, 2023 USD ($) shares

Oct. 31, 2023 shares

Aug. 31, 2023 USD ($)

Jun. 30, 2022 USD ($)

Apr. 30, 2022

Sep. 30, 2021 USD ($) shares

Sep. 30, 2022

Dec. 31, 2023 USD ($)

Dec. 31, 2022 USD ($) shares

Asset Acquisition, Contingent Consideration [Line Items]

Accumulated deficit

$ 4,260,328

$ 4,260,328

$ 4,048,415

Net loss from continuing operations

211,900

Net cash used in operating activities

235,046

316,219

Cash and cash equivalents

221,755

$ 221,755

113,006

Secured Debt | Term Loan Facility | Line of Credit | Subsequent Event

Asset Acquisition, Contingent Consideration [Line Items]

Number of tranches | tranche

4

Debt term

5 years

Line of credit maximum borrowing capacity

$ 175,000

Private Placement

Asset Acquisition, Contingent Consideration [Line Items]

Proceeds from stock offering

$ 75,000

$ 56,200

Percentage of gross proceeds

3%

Number of shares issued in transaction (in shares) | shares

2.3

2.3

10.7

At The Market Offering

Asset Acquisition, Contingent Consideration [Line Items]

Value of shares available for issue

$ 125,000

December Underwriting Agreement

Asset Acquisition, Contingent Consideration [Line Items]

Proceeds from stock offering

$ 118,100

$ 118,100

Number of shares issued in transaction (in shares) | shares

83.3

83.3

Maximum | Private Placement

Asset Acquisition, Contingent Consideration [Line Items]

Proceeds from stock offering

$ 75,000

April 2022 Reduction

Asset Acquisition, Contingent Consideration [Line Items]

Plans to reduce workforce, as a percent

30%

30%

Restatement of Previously Iss_3

Restatement of Previously Issued Financial Statements - Narrative (Details) $ in Thousands	Dec. 31, 2023 USD ($) lease_arrangement	Sep. 30, 2023 USD ($)	Jun. 30, 2023 USD ($)	Mar. 31, 2023 USD ($)	Dec. 31, 2022 USD ($)	Sep. 30, 2022 USD ($)	Jun. 30, 2022 USD ($)	Mar. 31, 2022 USD ($)	Dec. 31, 2021 USD ($)
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Stockholders' equity | $	$ 194,537				$ 134,333				$ 276,129
Revision of Prior Period, Error Correction, Adjustment | Adjustments to Leases
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Stockholders' equity | $		$ (69,708)	$ (52,569)	$ (62,051)	$ (59,700)	$ (62,961)	$ (67,215)	$ (80,474)	$ (95,634)
Manufacturing Facility
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Number of embedded lease arrangements incorrectly classified	3
Number of embedded lease arrangements identified in existing agreements	2
Office and Laboratory Testing Facility
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Number of embedded lease arrangements identified in existing agreements	1

Restatement of Previously Iss_4

Restatement of Previously Issued Financial Statements - Consolidated Balance Sheets (Details) - USD ($) $ / shares in Units, $ in Thousands	Dec. 31, 2023	Sep. 30, 2023	Jun. 30, 2023	Mar. 31, 2023	Dec. 31, 2022	Sep. 30, 2022	Jun. 30, 2022	Mar. 31, 2022	Dec. 31, 2021
Current assets:
Cash and cash equivalents	$ 221,755				$ 113,006
Marketable securities	0				67,321
Prepaid expenses	14,800				8,618
Receivables and other current assets	22,211				14,627
Total current assets	281,685				203,572
Marketable securities	0				1,414
Property, plant and equipment, net	65,936				67,636
Goodwill	5,646				5,646
Intangible assets, net	10,438				4,868
Operating lease right-of-use assets	201,113				230,885
Restricted cash and other non-current assets	54,343				55,793
Total assets	619,161				569,814
Current liabilities:
Accounts payable	18,498				14,867
Accrued expenses and other current liabilities	73,188				53,464
Operating lease liability, current portion	21,202				27,594
Finance lease liability, current portion	84,705				60,654
Total current liabilities	200,113				156,579
Operating lease liability, net of current portion	186,687				209,128
Finance lease liability, net of current portion	37,732				69,682
Other non-current liabilities	92				92
Total liabilities	424,624				435,481
Commitments and contingencies Note 12
Stockholders' equity:
Preferred stock, $0.01 par value, 5,000 shares authorized; 0 shares issued and    outstanding at December 31, 2023 and December 31, 2022	0				0
Common stock, $0.01 par value, 250,000 and 125,000 shares authorized; 192,772 and 82,923 shares issued and outstanding at December 31, 2023 and December 31, 2022, respectively	1,905				830
Additional paid-in capital	4,454,756				4,185,988
Accumulated other comprehensive loss	(1,796)				(4,070)
Accumulated deficit	(4,260,328)				(4,048,415)
Total stockholders' equity	194,537				134,333				$ 276,129
Total liabilities and stockholders' equity	$ 619,161				$ 569,814
Preferred stock, par value per share (in dollars per share)	$ 0.01	$ 0.01	$ 0.01	$ 0.01	$ 0.01	$ 0.01	$ 0.01	$ 0.01
Preferred stock, shares authorized (in shares)	5,000,000	5,000,000	5,000,000	5,000,000	5,000,000	5,000,000	5,000,000	5,000,000
Preferred stock, shares outstanding (in shares)	0	0	0	0	0	0	0	0
Preferred stock, shares issued (in shares)	0	0	0	0	0	0	0	0
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01	$ 0.01	$ 0.01	$ 0.01	$ 0.01	$ 0.01	$ 0.01
Common stock, shares authorized (in shares)	250,000,000	250,000,000	250,000,000	125,000,000	125,000,000	125,000,000	125,000,000	125,000,000
Common stock, shares issued (in shares)	192,772,000	107,022,000	106,454,000	106,370,000	82,923,000	82,880,000	73,551,000	71,438,000
Common stock, shares outstanding (in shares)	192,772,000	107,022,000	106,454,000	106,370,000	82,923,000	82,880,000	73,551,000	71,438,000
Previously Reported
Current assets:
Cash and cash equivalents		$ 165,347	$ 172,872	$ 239,045	$ 113,006	$ 66,478	$ 81,499	$ 106,260
Marketable securities		8,946	72,431	79,212	67,321	73,155	51,010	105,328
Prepaid expenses		11,431	13,597	13,466	8,374	8,270	24,473	31,798
Receivables and other current assets		17,383	15,435	15,539	10,787	12,535	10,476	11,531
Total current assets		247,076	287,977	351,071	199,488	160,438	167,458	254,917
Marketable securities					1,414	1,407	40,641	55,049
Property, plant and equipment, net		9,972	10,227	8,718	9,362	11,535	14,566	11,234
Goodwill		5,646	5,646	5,646	5,646	5,646	5,646	5,646
Intangible assets, net		5,368	5,490	5,613	4,868	0
Operating lease right-of-use assets		294,717	302,849	270,153	281,996	288,684	292,731	111,897
Restricted cash and other non-current assets		50,829	51,204	51,535	52,128	52,388	52,550	52,328
Total assets		613,608	663,393	692,736	554,902	520,098	573,592	491,071
Current liabilities:
Accounts payable		19,852	10,894	19,235	25,092	18,622	24,865	28,350
Accrued expenses and other current liabilities		57,768	56,531	45,294	51,985	64,314	75,550	89,032
Operating lease liability, current portion		71,684	67,591	51,404	51,160	43,791	48,446	25,510
Finance lease liability, current portion		0	0	0	0	0	0	0
Total current liabilities		158,957	135,016	115,933	128,237	126,727	148,861	142,892
Operating lease liability, net of current portion		232,023	239,266	221,971	230,230	234,422	244,522	84,828
Finance lease liability, net of current portion		0	0	0	0	0	0	0
Other non-current liabilities		92	92	92	92	92	93	92
Total liabilities		391,072	374,374	337,996	358,559	361,241	393,476	227,812
Stockholders' equity:
Preferred stock, $0.01 par value, 5,000 shares authorized; 0 shares issued and    outstanding at December 31, 2023 and December 31, 2022		0	0	0	0	0	0	0
Common stock, $0.01 par value, 250,000 and 125,000 shares authorized; 192,772 and 82,923 shares issued and outstanding at December 31, 2023 and December 31, 2022, respectively		1,071	1,065	1,064	830	829	735	714
Additional paid-in capital		4,333,594	4,328,489	4,322,025	4,186,086	4,181,393	4,126,012	4,109,081
Accumulated other comprehensive loss		(2,227)	(2,364)	(3,086)	(4,070)	(4,630)	(4,416)	(4,459)
Accumulated deficit		(4,109,902)	(4,038,171)	(3,965,263)	(3,986,503)	(4,018,735)	(3,942,215)	(3,842,077)
Total stockholders' equity		222,536	289,019	354,740	196,343	158,857	180,116	263,259	374,277
Total liabilities and stockholders' equity		613,608	663,393	692,736	554,902	520,098	573,592	491,071
Revision of Prior Period, Error Correction, Adjustment | Adjustments to Leases
Current assets:
Cash and cash equivalents		0	0	0	0	0	0	0
Marketable securities		0	0	0	0	0	0	0
Prepaid expenses		(2,040)	(2,162)	(2,082)	244	55	(667)	(1,549)
Receivables and other current assets		3,538	3,659	3,374	3,840	2,425	2,997	198
Total current assets		(1,707)	(341)	682	4,084	2,480	2,330	(1,351)
Marketable securities					0	0	0	0
Property, plant and equipment, net		63,398	51,722	53,223	58,585	(777)	(688)	(599)
Goodwill		0	0	0	0	0	0	0
Intangible assets, net		0	0	0	0	0
Operating lease right-of-use assets		(87,796)	(86,929)	(46,690)	(51,111)	(56,750)	(54,005)	(61,082)
Restricted cash and other non-current assets		3,665	3,665	3,665	3,665	3,665	3,665	3,665
Total assets		(22,440)	(31,883)	10,880	15,223	(51,382)	(48,698)	(59,367)
Current liabilities:
Accounts payable		(3,042)	(1,081)	(2,522)	(10,225)	(2,898)	(2,846)	(4,937)
Accrued expenses and other current liabilities		572	(599)	1,017	(520)	(13,432)	(12,189)	(15,597)
Operating lease liability, current portion		(46,160)	(42,427)	(24,784)	(23,566)	(20,322)	(22,583)	(9,262)
Finance lease liability, current portion		85,208	55,706	58,747	60,654	41,264	47,219	55,995
Total current liabilities		36,578	11,599	32,458	26,343	4,612	9,601	26,199
Operating lease liability, net of current portion		(39,456)	(40,930)	(18,176)	(21,102)	(24,069)	(27,634)	(46,407)
Finance lease liability, net of current portion		50,146	50,017	58,649	69,682	31,036	36,550	41,315
Other non-current liabilities		0	0	0	0	0	0	0
Total liabilities		47,268	20,686	72,931	74,923	11,579	18,517	21,107
Commitments and contingencies Note 12
Stockholders' equity:
Preferred stock, $0.01 par value, 5,000 shares authorized; 0 shares issued and    outstanding at December 31, 2023 and December 31, 2022		0	0	0	0	0	0	0
Common stock, $0.01 par value, 250,000 and 125,000 shares authorized; 192,772 and 82,923 shares issued and outstanding at December 31, 2023 and December 31, 2022, respectively		0	0	0	0	0	0	0
Additional paid-in capital		0	0	0	0	0	0	0
Accumulated other comprehensive loss		0	0	0	0	0	0	0
Accumulated deficit		(69,708)	(52,569)	(62,051)	(59,700)	(62,961)	(67,215)	(80,474)
Total stockholders' equity		(69,708)	(52,569)	(62,051)	(59,700)	(62,961)	(67,215)	(80,474)	(95,634)
Total liabilities and stockholders' equity		(22,440)	(31,883)	10,880	15,223	(51,382)	(48,698)	(59,367)
Revision of Prior Period, Error Correction, Adjustment | Other Adjustments
Current assets:
Cash and cash equivalents		0	0	0	0	0	0	0
Marketable securities		0	0	0	0	0	0	0
Prepaid expenses		0	0	0	0	0	0	0
Receivables and other current assets				(2,800)	0	0	0	0
Total current assets		(7,798)	602	(2,800)	0	0	0	0
Marketable securities					0	0	0	0
Property, plant and equipment, net		(280)	(235)	(270)	(311)	(358)	(406)	(459)
Goodwill		0	0	0	0	0	0	0
Intangible assets, net		0	0	0	0	4,972
Operating lease right-of-use assets				0		0	0	0
Restricted cash and other non-current assets		0	0	0	0	0	0	0
Total assets		(8,078)	367	(3,070)	(311)	4,614	(406)	(459)
Current liabilities:
Accounts payable		316	0	0	0	0	0	0
Accrued expenses and other current liabilities		0	1,999	(801)	1,999	1,998	1,999	1,999
Operating lease liability, current portion		0	0		0	0	0	0
Finance lease liability, current portion		0	0	0	0	0	0	0
Total current liabilities		(8,084)	1,999	(801)	1,999	1,998	1,999	1,999
Operating lease liability, net of current portion		0			0	0	0	0
Finance lease liability, net of current portion		0	0	0	0	0	0	0
Other non-current liabilities		0	0	0	0	0	0	0
Total liabilities		(8,084)	1,999	(801)	1,999	1,998	1,999	1,999
Commitments and contingencies Note 12
Stockholders' equity:
Preferred stock, $0.01 par value, 5,000 shares authorized; 0 shares issued and    outstanding at December 31, 2023 and December 31, 2022		0	0	0	0	0	0	0
Common stock, $0.01 par value, 250,000 and 125,000 shares authorized; 192,772 and 82,923 shares issued and outstanding at December 31, 2023 and December 31, 2022, respectively		0	0	0	0	0	0	0
Additional paid-in capital		(98)	(98)	(98)	(98)	(2,043)	(1,854)	(1,384)
Accumulated other comprehensive loss		0	0	0	0	0	0	0
Accumulated deficit		104	(1,534)	(2,171)	(2,212)	4,659	(551)	(1,074)
Total stockholders' equity		6	(1,632)	(2,269)	(2,310)	2,616	(2,405)	(2,458)	$ (2,514)
Total liabilities and stockholders' equity		$ (8,078)	$ 367	$ (3,070)	$ (311)	$ 4,614	$ (406)	$ (459)

Restatement of Previously Iss_5

Restatement of Previously Issued Financial Statements - Statements of Operations and Comprehensive Loss (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended						6 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2023	Jun. 30, 2023	Mar. 31, 2023	Sep. 30, 2022	Jun. 30, 2022	Mar. 31, 2022	Jun. 30, 2023	Jun. 30, 2022	Sep. 30, 2023	Sep. 30, 2022	Dec. 31, 2023	Dec. 31, 2022
Revenue:
Revenue											$ 29,065	$ 2,739
Other revenue											432	858
Total revenues											29,497	3,597
Cost of product revenue											33,527	10,077
Gross margin											(4,030)	(6,480)
Operating expenses:
Research and development											167,652	200,439
Selling, general and administrative											165,510	140,326
Restructuring expense											0	4,940
Loss on fixed assets disposal											92,930	102,000
Loss from operations											(244,262)	(250,185)
Interest income											9,869	1,032
Interest expense											(16,353)	(6,322)
Other income, net											38,707	25,250
Loss before income taxes											(212,039)	(230,225)
Income tax benefit (expense)											126	(117)
Net loss											$ (211,913)	$ (230,342)
Net income (loss) per share - basic (in dollars per share)											$ (1.93)	$ (2.93)
Net income (loss) per share - diluted (in dollars per share)											$ (1.93)	$ (2.93)
Weighted-average number of common shares used in computing net loss per share - basic (in shares)											109,825	78,585
Weighted-average number of common shares used in computing net loss per share - diluted (in shares)											109,825	78,585
Other comprehensive income (loss):
Other comprehensive income (loss)											$ 2,274	$ (1,159)
Comprehensive loss											(209,639)	(231,501)
Other comprehensive income (loss), tax	$ 0	$ 0	$ 0	$ 0	$ 0	$ 0	$ 0	$ 0	$ 0	$ 0	$ 0	0
Previously Reported
Revenue:
Revenue	12,281	6,837	2,296	0	1,331	1,408	9,133	2,739	21,414	2,739		2,739
Other revenue	111	53	85	71	188	537	138	725	249	795		858
Total revenues	12,392	6,890	2,381	71	1,519	1,945	9,271	3,464	21,663	3,534		3,597
Cost of product revenue	10,955	9,564	3,376	0	1,745	8,310	12,940	10,055	23,895	10,056		10,077
Gross margin	1,437	(2,674)	(995)	71	(226)	(6,365)	(3,669)	(6,591)	(2,232)	(6,522)		(6,480)
Operating expenses:
Research and development	45,463	42,274	46,144	53,149	63,841	77,875	88,418	141,716	133,881	194,864		240,764
Selling, general and administrative	40,703	40,349	37,354	33,402	36,694	36,106	77,703	72,800	118,406	106,201		136,908
Restructuring expense				(1,699)	6,639			6,639		4,940		4,940
Loss on fixed assets disposal			92,930				92,930		92,930			102,000
Loss from operations	(84,729)	(85,297)	8,437	(84,781)	(107,400)	(120,346)	(76,860)	(227,746)	(161,589)	(312,527)		(287,092)
Interest income	2,454	2,679	2,828	383	174	106	5,507	280	7,961	663		1,032
Interest expense	0	0	(3)	0	0	0	(3)	0	(3)	0		0
Other income, net	10,544	9,630	9,978	7,885	7,088	(1,912)	19,608	5,176	30,152	13,061		19,599
Loss before income taxes	(71,731)	(72,988)	21,240	(76,513)	(100,138)	(122,152)	(51,748)	(222,290)	(123,479)	(298,803)		(266,461)
Income tax benefit (expense)	0	80	0	(7)	0	0	80	0	80	(7)		(117)
Net loss	$ (71,731)	$ (72,908)	$ 21,240	$ (76,520)	$ (100,138)	$ (122,152)	$ (51,668)	$ (222,290)	$ (123,399)	$ (298,810)		$ (266,578)
Net income (loss) per share - basic (in dollars per share)	$ (0.66)	$ (0.67)	$ 0.21	$ (0.94)	$ (1.36)	$ (1.66)	$ (0.49)	$ (3.02)	$ (1.15)	$ (3.91)		$ (3.39)
Net income (loss) per share - diluted (in dollars per share)	$ (0.66)	$ (0.67)	$ 0.21	$ (0.94)	$ (1.36)	$ (1.66)	$ (0.49)	$ (3.02)	$ (1.15)	$ (3.91)		$ (3.39)
Weighted-average number of common shares used in computing net loss per share - basic (in shares)	109,098	108,685	102,920	81,543	73,767	73,688	105,819	73,727	106,924	76,361		78,585
Weighted-average number of common shares used in computing net loss per share - diluted (in shares)	109,098	108,685	103,303	81,543	73,767	73,688	105,819	73,727	106,924	76,361		78,585
Other comprehensive income (loss):
Other comprehensive income (loss)	$ 137	$ 722	$ 984	$ (214)	$ 43	$ (1,548)	$ 1,706	$ (1,505)	$ 1,843	$ (1,719)		$ (1,159)
Comprehensive loss	(71,594)	(72,186)	22,224	(76,734)	(100,095)	(123,700)	(49,962)	(223,795)	(121,556)	(300,529)		(267,737)
Revision of Prior Period, Error Correction, Adjustment | Adjustments to Leases
Revenue:
Revenue	0	0	0	0	0	0	0	0	0	0		0
Other revenue	0	0	0	0	0	0	0	0	0	0		0
Total revenues	0	0	0	0	0	0	0	0	0	0		0
Cost of product revenue	(1,829)	(2,867)	2,136	0	0	0	(731)	0	(2,560)	0		0
Gross margin	1,829	2,867	(2,136)	0	0	0	731	0	2,560	0		0
Operating expenses:
Research and development	14,757	(10,189)	(4,516)	(2,923)	(12,355)	(15,511)	(14,705)	(27,866)	52	(30,789)		(40,121)
Selling, general and administrative	68	113	113	273	(314)	(147)	226	(461)	294	(188)		3,516
Restructuring expense				0	0			0		0		0
Loss on fixed assets disposal			0				0		0			0
Loss from operations	(12,996)	12,943	2,267	2,650	12,669	15,658	15,210	28,327	2,214	30,977		36,605
Interest income	0	0	0	0	0	0	0	0	0	0		0
Interest expense	(4,311)	(3,750)	(4,267)	(1,552)	(922)	(1,028)	(8,017)	(1,950)	(12,328)	(3,502)		(6,322)
Other income, net	168	289	(351)	3,156	1,512	530	(62)	2,042	106	5,198		5,651
Loss before income taxes	(17,139)	9,482	(2,351)	4,254	13,259	15,160	7,131	28,419	(10,008)	32,673		35,934
Income tax benefit (expense)	0	0	0	0	0	0		0	0	0		0
Net loss	$ (17,139)	$ 9,482	$ (2,351)	$ 4,254	$ 13,259	$ 15,160	$ 7,131	$ 28,419	$ (10,008)	$ 32,673		$ 35,934
Net income (loss) per share - basic (in dollars per share)	$ (0.16)	$ 0.09	$ (0.02)	$ 0.05	$ 0.18	$ 0.21	$ 0.07	$ 0.39	$ (0.09)	$ 0.43		$ 0.46
Net income (loss) per share - diluted (in dollars per share)	$ (0.16)	$ 0.09	$ (0.02)	$ 0.05	$ 0.18	$ 0.21	$ 0.07	$ 0.39	$ (0.09)	$ 0.43		$ 0.46
Weighted-average number of common shares used in computing net loss per share - basic (in shares)	0	0	0	0	0	0	0	0	0	0		0
Weighted-average number of common shares used in computing net loss per share - diluted (in shares)	0	0	0	0	0	0	0	0	0	0		0
Other comprehensive income (loss):
Other comprehensive income (loss)	$ 0	$ 0	$ 0	$ 0	$ 0	$ 0	$ 0	$ 0	$ 0	$ 0		$ 0
Comprehensive loss	(17,139)	9,482	(2,351)	4,254	13,259	15,160	7,131	28,419	(10,008)	32,673		35,934
Revision of Prior Period, Error Correction, Adjustment | Other Adjustments
Revenue:
Revenue	0	0	0	0	0	0	0	0	0	0		0
Other revenue	0	0	0	0	0	0	0	0	0	0		0
Total revenues	0	0	0	0	0	0	0	0	0	0		0
Cost of product revenue	0	0	0	0	0	0	0	0	0	0		0
Gross margin	0	0	0	0	0	0	0	0	0	0		0
Operating expenses:
Research and development	(1,719)	(637)	(41)	(5,214)	(262)	(930)	(678)	(1,192)	(2,397)	(6,406)		(204)
Selling, general and administrative	0	0	0	4	(261)	(510)	0	(771)	0	(767)		(98)
Restructuring expense				0	0			0		0		0
Loss on fixed assets disposal			0				0		0			0
Loss from operations	1,719	637	41	5,210	523	1,440	678	1,963	2,397	7,173		302
Interest income	0	0	0	0	0	0	0	0	0	0		0
Interest expense	0	0	0	0	0	0	0	0	0	0		0
Other income, net	(81)	0	0	0	0	0	0	0	(81)	0		0
Loss before income taxes	1,638	637	41	5,210	523	1,440	678	1,963	2,316	7,173		302
Income tax benefit (expense)	0	0	0	0	0	0	0	0	0	0		0
Net loss	$ 1,638	$ 637	$ 41	$ 5,210	$ 523	$ 1,440	$ 678	$ 1,963	$ 2,316	$ 7,173		$ 302
Net income (loss) per share - basic (in dollars per share)	$ 0.02	$ 0.01	$ 0	$ 0.06	$ 0.01	$ 0.02	$ 0.01	$ 0.03	$ 0.02	$ 0.09		$ 0
Net income (loss) per share - diluted (in dollars per share)	$ 0.02	$ 0.01	$ 0	$ 0.06	$ 0.01	$ 0.02	$ 0.01	$ 0.03	$ 0.02	$ 0.09		$ 0
Weighted-average number of common shares used in computing net loss per share - basic (in shares)	0	0	0	0	0	0	0	0	0	0		0
Weighted-average number of common shares used in computing net loss per share - diluted (in shares)	0	0	0	0	0	0	0	0	0	0		0
Other comprehensive income (loss):
Other comprehensive income (loss)	$ 0	$ 0	$ 0	$ 0	$ 0	$ 0	$ 0	$ 0	$ 0	$ 0		$ 0
Comprehensive loss	$ 1,638	$ 637	$ 41	$ 5,210	$ 523	$ 1,440	$ 678	$ 1,963	$ 2,316	$ 7,173		$ 302

Restatement of Previously Iss_6

Restatement of Previously Issued Financial Statements - Statements of Stockholders' Equity (Details) - USD ($) $ in Thousands	3 Months Ended						6 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2023	Jun. 30, 2023	Mar. 31, 2023	Sep. 30, 2022	Jun. 30, 2022	Mar. 31, 2022	Jun. 30, 2023	Jun. 30, 2022	Sep. 30, 2023	Sep. 30, 2022	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Common stock, shares outstanding (in shares)	107,022,000	106,454,000	106,370,000	82,880,000	73,551,000	71,438,000	106,454,000	73,551,000	107,022,000	82,880,000	192,772,000	82,923,000
Stockholders' equity											$ 194,537	$ 134,333	$ 276,129
Vesting of restricted stock units											$ (196)	0
Exercise of stock options (in shares)											3,000
Exercise of stock options											$ 92	16
Purchase of common stock under ESPP											429	239
Issuance of common stock											248,367	54,067
Issuance of unrestricted stock awards to settle accrued employee compensation												1
Stock-based compensation											21,151	35,382
Other comprehensive income											2,274	(1,159)
Net loss											$ (211,913)	$ (230,342)
Common shares
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Common stock, shares outstanding (in shares)											192,772,000	82,923,000	71,115,000
Stockholders' equity											$ 1,905	$ 830	$ 711
Vesting of restricted stock units (in shares)											1,092,000	979,000
Vesting of restricted stock units											$ 10	$ 10
Exercise of stock options (in shares)											24,000	7,000
Purchase of common stock under ESPP (in shares)											135,000	68,000
Purchase of common stock under ESPP											$ 2	$ 1
Issuance of common stock (in shares)											106,333,000	10,742,000
Issuance of common stock											$ 1,063	$ 107
Issuance of unrestricted stock awards to settle accrued employee compensation (in shares)												12,000
Issuance of unrestricted stock awards to settle accrued employee compensation												$ 1
Additional paid-in capital
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stockholders' equity											4,454,756	4,185,988	4,096,402
Vesting of restricted stock units											(206)	(10)
Exercise of stock options											92	16
Purchase of common stock under ESPP											427	238
Issuance of common stock											247,304	53,960
Stock-based compensation											21,151	35,382
Accumulated other comprehensive loss
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stockholders' equity											(1,796)	(4,070)	(2,911)
Other comprehensive income											2,274	(1,159)
Accumulated Deficit
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stockholders' equity											(4,260,328)	(4,048,415)	(3,818,073)
Net loss											$ (211,913)	(230,342)
Previously Reported
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stockholders' equity	$ 222,536	$ 289,019	$ 354,740	$ 158,857	$ 180,116	$ 263,259	$ 289,019	$ 180,116	$ 222,536	$ 158,857		196,343	$ 374,277
Vesting of restricted stock units	0	0	(195)	0	0	0						0
Exercise of stock options	8	77	7		1	1						16
Purchase of common stock under ESPP			227	239								239
Issuance of common stock	(50)		130,291	46,024	8,043							54,067
Issuance of unrestricted stock awards to settle accrued employee compensation												1
Stock-based compensation	5,153	6,388	5,843	9,212	8,908	12,681						35,480
Other comprehensive income	137	722	984	(214)	43	(1,548)						(1,159)
Net loss	$ (71,731)	$ (72,908)	$ 21,240	$ (76,520)	$ (100,138)	$ (122,152)	$ (51,668)	$ (222,290)	$ (123,399)	$ (298,810)		$ (266,578)
Previously Reported | Common shares
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Common stock, shares outstanding (in shares)	107,022,000	106,454,000	106,370,000	82,880,000	73,551,000	71,438,000	106,454,000	73,551,000	107,022,000	82,880,000		82,923,000	71,115,000
Stockholders' equity	$ 1,071	$ 1,065	$ 1,064	$ 829	$ 735	$ 714	$ 1,065	$ 735	$ 1,071	$ 829		$ 830	$ 711
Vesting of restricted stock units (in shares)	566,000	65,000	382,000	572,000	60,000	310,000						979,000
Vesting of restricted stock units	$ 6	$ 1	$ 3	$ 6	$ 1	$ 3						$ 10
Exercise of stock options (in shares)	2,000	19,000	3,000		1,000	1,000						7,000
Purchase of common stock under ESPP (in shares)			62,000	67,000								68,000
Purchase of common stock under ESPP			$ 1	$ 1								$ 1
Issuance of common stock (in shares)			23,000,000	8,690,000	2,052,000							10,742,000
Issuance of common stock			$ 230	$ 87	$ 20							$ 107
Issuance of unrestricted stock awards to settle accrued employee compensation (in shares)						12,000						12,000
Issuance of unrestricted stock awards to settle accrued employee compensation												$ 1
Previously Reported | Additional paid-in capital
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stockholders' equity	$ 4,333,594	$ 4,328,489	4,322,025	4,181,393	4,126,012	$ 4,109,081	4,328,489	4,126,012	4,333,594	4,181,393		4,186,086	4,096,402
Vesting of restricted stock units	(6)	(1)	(198)	(6)	(1)	(3)						(10)
Exercise of stock options	8	77	7		1	1						16
Purchase of common stock under ESPP			226	238								238
Issuance of common stock	(50)		130,061	45,937	8,023							53,960
Stock-based compensation	5,153	6,388	5,843	9,212	8,908	12,681						35,480
Previously Reported | Accumulated other comprehensive loss
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stockholders' equity	(2,227)	(2,364)	(3,086)	(4,630)	(4,416)	(4,459)	(2,364)	(4,416)	(2,227)	(4,630)		(4,070)	(2,911)
Other comprehensive income	137	722	984	(214)	43	(1,548)						(1,159)
Previously Reported | Accumulated Deficit
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stockholders' equity	(4,109,902)	(4,038,171)	(3,965,263)	(4,018,735)	(3,942,215)	(3,842,077)	(4,038,171)	(3,942,215)	(4,109,902)	(4,018,735)		(3,986,503)	(3,719,925)
Net loss	(71,731)	(72,908)	21,240	(76,520)	(100,138)	(122,152)						(266,578)
Revision of Prior Period, Error Correction, Adjustment | Adjustments to Leases
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stockholders' equity	(69,708)	(52,569)	(62,051)	(62,961)	(67,215)	(80,474)	(52,569)	(67,215)	(69,708)	(62,961)		(59,700)	$ (95,634)
Net loss	$ (17,139)	$ 9,482	$ (2,351)	$ 4,254	$ 13,259	$ 15,160	$ 7,131	$ 28,419	$ (10,008)	$ 32,673		$ 35,934
Revision of Prior Period, Error Correction, Adjustment | Adjustments to Leases | Common shares
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Common stock, shares outstanding (in shares)	0	0	0	0	0	0	0	0	0	0		0	0
Stockholders' equity	$ 0	$ 0	$ 0	$ 0	$ 0	$ 0	$ 0	$ 0	$ 0	$ 0		$ 0	$ 0
Revision of Prior Period, Error Correction, Adjustment | Adjustments to Leases | Additional paid-in capital
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stockholders' equity	0	0	0	0	0	0	0	0	0	0		0	0
Revision of Prior Period, Error Correction, Adjustment | Adjustments to Leases | Accumulated other comprehensive loss
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stockholders' equity	0	0	0	0	0	0	0	0	0	0		0	0
Revision of Prior Period, Error Correction, Adjustment | Adjustments to Leases | Accumulated Deficit
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stockholders' equity	(69,708)	(52,569)	(62,051)	(62,961)	(67,215)	(80,474)	(52,569)	(67,215)	(69,708)	(62,961)		(59,700)	(95,634)
Net loss	(17,139)	9,482	(2,351)	4,254	13,259	15,160						35,934
Revision of Prior Period, Error Correction, Adjustment | Other Adjustments
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stockholders' equity	6	(1,632)	(2,269)	2,616	(2,405)	(2,458)	(1,632)	(2,405)	6	2,616		(2,310)	$ (2,514)
Stock-based compensation				(189)	(470)	(1,384)						(98)
Net loss	$ 1,638	$ 637	$ 41	$ 5,210	$ 523	$ 1,440	$ 678	$ 1,963	$ 2,316	$ 7,173		$ 302
Revision of Prior Period, Error Correction, Adjustment | Other Adjustments | Common shares
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Common stock, shares outstanding (in shares)	0	0	0	0	0	0	0	0	0	0		0	0
Stockholders' equity	$ 0	$ 0	$ 0	$ 0	$ 0	$ 0	$ 0	$ 0	$ 0	$ 0		$ 0	$ 0
Revision of Prior Period, Error Correction, Adjustment | Other Adjustments | Additional paid-in capital
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stockholders' equity	(98)	(98)	(98)	(2,043)	(1,854)	(1,384)	(98)	(1,854)	(98)	(2,043)		(98)	0
Stock-based compensation				(189)	(470)	(1,384)						(98)
Revision of Prior Period, Error Correction, Adjustment | Other Adjustments | Accumulated other comprehensive loss
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stockholders' equity	0	0	0	0	0	0	0	0	0	0		0	0
Revision of Prior Period, Error Correction, Adjustment | Other Adjustments | Accumulated Deficit
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stockholders' equity	104	(1,534)	(2,171)	4,659	(551)	(1,074)	$ (1,534)	$ (551)	$ 104	$ 4,659		(2,212)	$ (2,514)
Net loss	$ 1,638	$ 637	$ 41	$ 5,210	$ 523	$ 1,440						$ 302

Restatement of Previously Iss_7

Restatement of Previously Issued Financial Statements - Statements of Cash Flows (Details) - USD ($) $ in Thousands	3 Months Ended						6 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2023	Jun. 30, 2023	Mar. 31, 2023	Sep. 30, 2022	Jun. 30, 2022	Mar. 31, 2022	Jun. 30, 2023	Jun. 30, 2022	Sep. 30, 2023	Sep. 30, 2022	Dec. 31, 2023	Dec. 31, 2022
Cash flows from operating activities:
Net loss											$ (211,913)	$ (230,342)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization											28,525	8,344
Stock-based compensation expense											19,429	35,090
Noncash research and development expense (finance lease)											21,198	11,180
Noncash operating lease expense											29,772	23,562
Loss on fixed assets disposal											(92,930)	(102,000)
Unrealized loss (gain) on equity securities											0	3,135
Excess inventory reserve											15,363	7,519
Other non-cash items											24	4,138
Gain on foreign currency exchange rates											167	(1,801)
Changes in operating assets and liabilities:
Prepaid expenses and other assets											(3,894)	(4,820)
Inventory											(36,560)	(7,227)
Operating lease right-of-use assets												0
Accounts payable											2,841	(7,709)
Accrued expenses and other liabilities											13,353	(45,974)
Accrued interest payable under finance lease											3,426	4,758
Operating lease liabilities											(28,887)	(14,072)
Net cash used in operating activities											(235,046)	(316,219)
Cash flows from investing activities:
Purchase of property, plant and equipment											(4,189)	(8,208)
Proceeds from maturities of marketable securities											108,521	131,445
Proceeds from sales of marketable securities											5,853	30,216
Purchase of intangible assets											(4,868)	(5,000)
Proceeds from sale of priority review voucher											92,930	102,000
Net cash provided by investing activities											154,950	250,453
Cash flows from financing activities:
Proceeds from exercise of stock options and ESPP contributions												16
Principal payments on finance leases											(54,367)	(36,734)
Proceeds from public offering of common stock, net of issuance costs											248,198	54,237
Net cash provided by financing activities											196,248	17,519
Increase (decrease) in cash, cash equivalents and restricted cash											116,152	(48,247)
Cash, cash equivalents and restricted cash at beginning of year			$ 158,445			$ 206,692	$ 158,445	$ 206,692	$ 158,445	$ 206,692	158,445	206,692
Cash, cash equivalents and restricted cash at end of year											274,597	158,445
Reconciliation of cash, cash equivalents and restricted cash:
Cash and cash equivalents											221,755	113,006
Restricted cash included in receivables and other current assets											9,202	1,502
Restricted cash included in restricted cash and other non-current assets											43,640	43,937
Total cash, cash equivalents and restricted cash											274,597	158,445
Supplemental cash flow disclosures:
Right-of-use assets obtained in exchange for operating lease liabilities												221,036
Increase (Reduction) of right of use asset and associated operating lease liability due to lease reassessment												0
Purchases of property, plant and equipment included in accounts payable and accrued expenses											884	(3)
Offering expenses included in accounts payable and accrued expenses											964	170
Right-of-use assets obtained in exchange for finance lease liabilities											21,929	73,443
Cash paid (refunded) during the period for income taxes												253
Public Offering
Cash flows from financing activities:
Proceeds from public offering of common stock, net of issuance costs			130,645				130,122	8,043	130,072	54,365		54,237
Previously Reported
Cash flows from operating activities:
Net loss	$ (71,731)	$ (72,908)	21,240	$ (76,520)	$ (100,138)	(122,152)	(51,668)	(222,290)	(123,399)	(298,810)		(266,578)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization			1,082			1,014	2,052	2,358	3,124	3,745		5,001
Stock-based compensation expense			5,391			12,390	11,145	21,298	16,013	30,509		35,188
Noncash research and development expense (finance lease)			0			0	0	0	0	0		0
Noncash operating lease expense			0			0	0	0	0	0		0
Loss on fixed assets disposal			(92,930)				(92,930)		(92,930)			(102,000)
Unrealized loss (gain) on equity securities						2,508		3,135		3,135		3,135
Excess inventory reserve			228			7,519	3,939	7,519	5,333	7,519		7,519
Other non-cash items			237			189	343	661	19	2,890		3,904
Gain on foreign currency exchange rates			0			0	0	0	0	0		0
Changes in operating assets and liabilities:
Prepaid expenses and other assets			(9,335)			(4,303)	(9,082)	(9,629)	(523)	(6,197)		3,260
Inventory			(3,586)			(8,756)	(16,496)		(24,931)			(7,227)
Operating lease right-of-use assets			11,829			6,517	24,102	17,636	40,101	29,650		42,706
Accounts payable			(6,443)			2,467	(14,767)	(1,175)	(5,787)	(7,552)		(920)
Accrued expenses and other liabilities			(9,065)			(16,561)	3,625	(28,565)	7,125	(39,046)		(51,228)
Accrued interest payable under finance lease			0			0	0	0	0	0		0
Operating lease liabilities			(8,001)			(6,128)	(19,488)	(10,602)	(30,506)	(22,523)		(25,713)
Net cash used in operating activities			(86,638)			(125,296)	(159,363)	(219,654)	(221,209)	(296,680)		(352,953)
Cash flows from investing activities:
Purchase of property, plant and equipment			(232)			(857)	(937)	(6,836)	(2,975)	(8,100)		(8,208)
Proceeds from maturities of marketable securities			4,021			70,783	26,521	108,225	99,521	125,095		131,445
Proceeds from sales of marketable securities			5,853				5,853	30,213	5,853	30,216		30,216
Purchase of intangible assets			(868)				(868)		(868)	0		(5,000)
Proceeds from sale of priority review voucher			92,972				92,930		92,930			102,000
Net cash provided by investing activities			82,136			69,926	89,081	131,602	151,164	147,211		250,453
Cash flows from financing activities:
Proceeds from exercise of stock options and ESPP contributions			7			9	85		93	3		16
Principal payments on finance leases			0			0	0	0	0	0		0
Net cash provided by financing activities			130,456			9	130,011	8,043	129,969	54,368		54,253
Increase (decrease) in cash, cash equivalents and restricted cash			125,954			(55,361)	59,729	(80,009)	59,924	(95,101)		(48,247)
Cash, cash equivalents and restricted cash at beginning of year	218,174	284,399	158,445	126,684	151,332	206,692	158,445	206,692	158,445	206,692	158,445	206,692
Cash, cash equivalents and restricted cash at end of year	218,369	218,174	284,399	111,592	126,684	151,332	218,174	126,684	218,369	111,592		158,445
Reconciliation of cash, cash equivalents and restricted cash:
Cash and cash equivalents	165,347	172,872	239,045	66,478	81,499	106,260	172,872	81,499	165,347	66,478		113,006
Restricted cash included in receivables and other current assets	8,885	1,364	1,417	1,565	1,635	1,822	1,364	1,635	8,885	1,565		1,502
Restricted cash included in restricted cash and other non-current assets	44,137	43,938	43,937	43,549	43,550	43,250	43,938	43,550	44,137	43,549		43,937
Total cash, cash equivalents and restricted cash	218,369	218,174	284,399	111,592	126,684	151,332	218,174	126,684	218,369	111,592		158,445
Supplemental cash flow disclosures:
Right-of-use assets obtained in exchange for operating lease liabilities						26,882	44,968	218,836		229,636		236,003
Increase (Reduction) of right of use asset and associated operating lease liability due to lease reassessment							(14)		8,003	(2,833)		(2,833)
Purchases of property, plant and equipment included in accounts payable and accrued expenses			189			2,134	2,290	842	941	176		(3)
Offering expenses included in accounts payable and accrued expenses			523						248	298		170
Right-of-use assets obtained in exchange for finance lease liabilities			0				0		0	0		0
Cash paid (refunded) during the period for income taxes			2				7		5			253
Revision of Prior Period, Error Correction, Adjustment | Adjustments to Leases
Cash flows from operating activities:
Net loss	(17,139)	9,482	(2,351)	4,254	13,259	15,160	7,131	28,419	(10,008)	32,673		35,934
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization			5,131			89	10,274	179	16,648	268		3,547
Stock-based compensation expense			0			0	0	0	0	0		0
Noncash research and development expense (finance lease)			1,441			4,050	434	4,050	22,223	11,866		11,180
Noncash operating lease expense			7,423			3,035	14,966	9,738	23,965	16,517		23,562
Loss on fixed assets disposal			0				0		0			0
Unrealized loss (gain) on equity securities						0		0		0		0
Excess inventory reserve			0			0	0	0	1,554	0		0
Other non-cash items			0			0	0	234	0	234		234
Gain on foreign currency exchange rates			(108)			(530)	(281)	(1,874)	(1,062)	(3,301)		(1,801)
Changes in operating assets and liabilities:
Prepaid expenses and other assets			2,846			(2,591)	2,642	(6,389)	2,640	(6,508)		(8,080)
Inventory			610			0	1,838		1,651			0
Operating lease right-of-use assets			(11,829)			(6,517)	(24,102)	(17,636)	(40,101)	(29,650)		(42,706)
Accounts payable			7,703			(1,501)	9,144	590	7,183	537		(6,789)
Accrued expenses and other liabilities			1,859			(12,618)	(573)	(9,308)	583	(10,388)		5,254
Accrued interest payable under finance lease			915			1,014	819	1,924	3,203	3,464		4,758
Operating lease liabilities			1,640			5,981	6,212	8,656	11,820	11,580		11,641
Net cash used in operating activities			15,280			5,572	28,504	18,583	40,299	27,292		36,734
Cash flows from investing activities:
Purchase of property, plant and equipment			0			0	0	0	0	0		0
Proceeds from maturities of marketable securities			0			0	0	0	0	0		0
Proceeds from sales of marketable securities			0				0	0	0	0		0
Purchase of intangible assets			0				0		0	0		0
Proceeds from sale of priority review voucher			0				0		0			0
Net cash provided by investing activities			0			0	0	0	0	0		0
Cash flows from financing activities:
Proceeds from exercise of stock options and ESPP contributions			0			0	0		0	0		0
Principal payments on finance leases			(15,280)			(5,572)	(28,504)	(18,583)	(40,299)	(27,292)		(36,734)
Proceeds from public offering of common stock, net of issuance costs							0		0	0
Net cash provided by financing activities			(15,280)			(5,572)	(28,504)	(18,583)	(40,299)	(27,292)		(36,734)
Increase (decrease) in cash, cash equivalents and restricted cash			0			0	0	0	0	0		0
Cash, cash equivalents and restricted cash at beginning of year	0	0	0	0	0	0	0	0	0	0	0	0
Cash, cash equivalents and restricted cash at end of year	0	0	0	0	0	0	0	0	0	0		0
Reconciliation of cash, cash equivalents and restricted cash:
Cash and cash equivalents	0	0	0	0	0	0	0	0	0	0		0
Restricted cash included in receivables and other current assets	0	0	0	0	0	0	0	0	0	0		0
Restricted cash included in restricted cash and other non-current assets	0	0	0	0	0	0	0	0	0	0		0
Total cash, cash equivalents and restricted cash	0	0	0	0	0	0	0	0	0	0		0
Supplemental cash flow disclosures:
Right-of-use assets obtained in exchange for operating lease liabilities						(1,829)	(44,968)	(3,796)		(14,596)		(14,967)
Increase (Reduction) of right of use asset and associated operating lease liability due to lease reassessment							14		(8,003)	2,833		2,833
Purchases of property, plant and equipment included in accounts payable and accrued expenses			0			0	0	0	0	0		0
Offering expenses included in accounts payable and accrued expenses			0						0	0		0
Right-of-use assets obtained in exchange for finance lease liabilities			(214)				3,436		21,508	10,800		73,443
Cash paid (refunded) during the period for income taxes			0				0		0			0
Revision of Prior Period, Error Correction, Adjustment | Adjustments to Leases | Public Offering
Cash flows from financing activities:
Proceeds from public offering of common stock, net of issuance costs			0					0				0
Revision of Prior Period, Error Correction, Adjustment | Other Adjustments
Cash flows from operating activities:
Net loss	1,638	637	41	5,210	523	1,440	678	1,963	2,316	7,173		302
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization			(41)			(56)	(76)	(108)	(112)	(129)		(204)
Stock-based compensation expense			0			(1,384)	0	(1,855)	0	(2,044)		(98)
Noncash research and development expense (finance lease)			0			0	0	0	0	0		0
Noncash operating lease expense			0			0	0	0	0	0		0
Loss on fixed assets disposal			0				0		0			0
Unrealized loss (gain) on equity securities						0		0		0		0
Excess inventory reserve			2,355			0	2,339	0	2,315	0		0
Other non-cash items			0			0	0	0	81	0		0
Gain on foreign currency exchange rates			0			0	0	0	0	0		0
Changes in operating assets and liabilities:
Prepaid expenses and other assets			2,800			0	0	0	0	0		0
Inventory			(2,355)			0	(2,941)		(2,917)			0
Operating lease right-of-use assets			0			0	0	0	0	0		0
Accounts payable			0			0	0	0	316	0		0
Accrued expenses and other liabilities			0			0	0	0	(1,999)	0		0
Accrued interest payable under finance lease			0			0	0	0	0	0		0
Operating lease liabilities			0			0	0	0	0	0		0
Net cash used in operating activities			0			0	0	0	0	5,000		0
Cash flows from investing activities:
Purchase of property, plant and equipment			0			0	0	0	0	0		0
Proceeds from maturities of marketable securities			0			0	0	0	0	0		0
Proceeds from sales of marketable securities			0				0	0	0	0		0
Purchase of intangible assets			0				0		0	(5,000)		0
Proceeds from sale of priority review voucher			0				0		0			0
Net cash provided by investing activities			0			0	0	0	0	(5,000)		0
Cash flows from financing activities:
Proceeds from exercise of stock options and ESPP contributions			0			0	0		0	0		0
Principal payments on finance leases			0			0	0	0	0	0		0
Proceeds from public offering of common stock, net of issuance costs							0		0	0
Net cash provided by financing activities			0			0	0	0	0	0		0
Increase (decrease) in cash, cash equivalents and restricted cash			0			0	0	0	0	0		0
Cash, cash equivalents and restricted cash at beginning of year	0	0	0	0	0	0	0	0	0	0	$ 0	0
Cash, cash equivalents and restricted cash at end of year	0	0	0	0	0	0	0	0	0	0		0
Reconciliation of cash, cash equivalents and restricted cash:
Cash and cash equivalents	0	0	0	0	0	0	0	0	0	0		0
Restricted cash included in receivables and other current assets	0	0	0	0	0	0	0	0	0	0		0
Restricted cash included in restricted cash and other non-current assets	0	0	0	0	0	0	0	0	0	0		0
Total cash, cash equivalents and restricted cash	$ 0	$ 0	0	$ 0	$ 0	0	0	0	0	0		0
Supplemental cash flow disclosures:
Right-of-use assets obtained in exchange for operating lease liabilities						0	0	0		0		0
Increase (Reduction) of right of use asset and associated operating lease liability due to lease reassessment							0		0	0		0
Purchases of property, plant and equipment included in accounts payable and accrued expenses			0			$ 0	0	0	0	0		0
Offering expenses included in accounts payable and accrued expenses			0						0	0		0
Right-of-use assets obtained in exchange for finance lease liabilities			0				0		0	$ 0		0
Cash paid (refunded) during the period for income taxes			0				$ 0		$ 0			0
Revision of Prior Period, Error Correction, Adjustment | Other Adjustments | Public Offering
Cash flows from financing activities:
Proceeds from public offering of common stock, net of issuance costs			$ 0					$ 0				$ 0

Summary of significant accoun_4

Summary of significant accounting policies and basis of presentation - Narrative (Detail)	12 Months Ended
	Dec. 31, 2023 USD ($) segment	Dec. 31, 2022 USD ($)
Line of Credit Facility [Line Items]
Number of operating segments | segment	1
Goodwill, impaired, accumulated impairment loss	$ 0
Percent of contract asset	100%
Upfront purchase price as a percent of contract asset	90%
Percent payable when the financial institution receives payment	10%
Due to factor	$ 2,520,000	$ 0
Factoring Agreement | Revolving Credit Facility
Line of Credit Facility [Line Items]
Line of credit maximum borrowing capacity	$ 100,000,000

Summary of significant accoun_5

Summary of significant accounting policies and basis of presentation - Estimated Useful Lives of Assets (Detail)	Dec. 31, 2023
Building
Property, Plant and Equipment [Line Items]
Estimated useful lives of assets	40 years
Computer equipment and software
Property, Plant and Equipment [Line Items]
Estimated useful lives of assets	3 years
Furniture and fixtures
Property, Plant and Equipment [Line Items]
Estimated useful lives of assets	5 years
Laboratory equipment | Minimum
Property, Plant and Equipment [Line Items]
Estimated useful lives of assets	3 years
Laboratory equipment | Maximum
Property, Plant and Equipment [Line Items]
Estimated useful lives of assets	5 years

Product revenue and reserves -

Product revenue and reserves - Narrative (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Revenue from External Customer [Line Items]
Revenue	$ 29,065	$ 2,739
Revenue from Contract with Customer Benchmark | Customer Concentration Risk
Revenue from External Customer [Line Items]
Concentration risk, percentage		100%
Customer One | Revenue from Contract with Customer Benchmark | Customer Concentration Risk
Revenue from External Customer [Line Items]
Concentration risk, percentage	49%
Customer Two | Revenue from Contract with Customer Benchmark | Customer Concentration Risk
Revenue from External Customer [Line Items]
Concentration risk, percentage	35%

Product revenue and reserves _2

Product revenue and reserves - Summary of Product Revenue (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Revenue from External Customer [Line Items]
Revenue	$ 29,065	$ 2,739
ZYNTEGLO
Revenue from External Customer [Line Items]
Revenue	16,692	2,739
SKYSONA
Revenue from External Customer [Line Items]
Revenue	$ 12,373	$ 0

Product revenue and reserves _3

Product revenue and reserves - Rebate Liability (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2023 USD ($)
Contract with Customer, Refund Liability [Roll Forward]
Balance at December 31, 2022	$ 0
Provision for rebates	5,365
Payments/credits	0
Balance at December 31, 2023	$ 5,365

Marketable securities - Summary

Marketable securities - Summary of Marketable Securities Held (Detail) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Debt Securities, Available-for-sale [Line Items]
Amortized cost / cost	$ 0	$ 70,494
Unrealized gains	0	0
Unrealized losses	0	(1,759)
Fair value	0	68,735
U.S. government agency securities and treasuries
Debt Securities, Available-for-sale [Line Items]
Amortized cost / cost	0	67,970
Unrealized gains	0	0
Unrealized losses	0	(1,733)
Fair value	$ 0	66,237
Corporate bonds
Debt Securities, Available-for-sale [Line Items]
Amortized cost / cost		2,524
Unrealized gains		0
Unrealized losses		(26)
Fair value		$ 2,498

Marketable securities - Narrati

Marketable securities - Narrative (Detail) - USD ($)	Dec. 31, 2023	Dec. 31, 2022
Investments, Debt and Equity Securities [Abstract]
Debt securities, available-for-sale, noncurrent	$ 0	$ 0

Fair value measurements - Recor

Fair value measurements - Recorded Amount of Assets and Liabilities Measured at Fair Value on Recurring Basis (Detail) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Assets:
Marketable securities	$ 0	$ 68,735
Corporate bonds
Assets:
Marketable securities		2,498
Fair value, measurements, recurring
Assets:
Cash and cash equivalents	221,755	113,006
Beneficiary interest in factored invoices	560
Total assets	222,315	181,741
Fair value, measurements, recurring | U.S. government agency securities and treasuries
Assets:
Marketable securities	0	66,237
Fair value, measurements, recurring | Corporate bonds
Assets:
Marketable securities		2,498
Fair value, measurements, recurring | Quoted prices in active markets (Level 1)
Assets:
Cash and cash equivalents	221,755	113,006
Beneficiary interest in factored invoices	0
Total assets	221,755	113,006
Fair value, measurements, recurring | Quoted prices in active markets (Level 1) | U.S. government agency securities and treasuries
Assets:
Marketable securities	0	0
Fair value, measurements, recurring | Quoted prices in active markets (Level 1) | Corporate bonds
Assets:
Marketable securities		0
Fair value, measurements, recurring | Significant other observable inputs (Level 2)
Assets:
Cash and cash equivalents	0	0
Beneficiary interest in factored invoices	0
Total assets	0	68,735
Fair value, measurements, recurring | Significant other observable inputs (Level 2) | U.S. government agency securities and treasuries
Assets:
Marketable securities	0	66,237
Fair value, measurements, recurring | Significant other observable inputs (Level 2) | Corporate bonds
Assets:
Marketable securities		2,498
Fair value, measurements, recurring | Significant unobservable inputs (Level 3)
Assets:
Cash and cash equivalents	0	0
Beneficiary interest in factored invoices	560
Total assets	560	0
Fair value, measurements, recurring | Significant unobservable inputs (Level 3) | U.S. government agency securities and treasuries
Assets:
Marketable securities	$ 0	0
Fair value, measurements, recurring | Significant unobservable inputs (Level 3) | Corporate bonds
Assets:
Marketable securities		$ 0

Fair value measurements - Narra

Fair value measurements - Narrative (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Fair Value Disclosures [Abstract]
Realized gain (loss) recognized on sale	$ (100,000)	$ 0
Interest receivable	300,000	100,000
Interest receivable, write-off	$ 0	$ 0

Fair value measurements - Sched

Fair value measurements - Schedule of Unrealized Loss on Investments (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Fair value
Less than 12 months	$ 0	$ 0
12 months or greater	0	68,735
Total	0	68,735
Unrealized losses
Less than 12 months	0	0
12 months or greater	0	(1,759)
Total	0	(1,759)
U.S. government agency securities and treasuries
Fair value
Less than 12 months	0	0
12 months or greater	0	66,237
Total	0	66,237
Unrealized losses
Less than 12 months	0	0
12 months or greater	0	(1,733)
Total	$ 0	(1,733)
Corporate bonds
Fair value
Less than 12 months		0
12 months or greater		2,498
Total		2,498
Unrealized losses
Less than 12 months		0
12 months or greater		(26)
Total		$ (26)

Fair value measurements - Facto

Fair value measurements - Factoring Agreement Reconciliation of Beginning and Ending Balances (Details) - Beneficial Interest $ in Thousands	12 Months Ended
	Dec. 31, 2023 USD ($)
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Level 3 financial assets, beginning of period	$ 0
Beneficiary interest obtained in transferred invoices	560
Proceeds from previously transferred invoices	0
Level 3 financial assets, end of period	$ 560

Inventory - Schedule of Invento

Inventory - Schedule of Inventory (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Inventory Disclosure [Abstract]
Raw materials	$ 2,329	$ 0
Work in progress	17,375	0
Finished goods	3,215	0
Inventory	$ 22,919	$ 0

Property, plant and equipment_3

Property, plant and equipment, net - Summary of Property, Plant and Equipment Net (Detail) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Property, Plant and Equipment [Line Items]
Finance lease right of use assets	$ 84,524	$ 71,179
Total property, plant and equipment	107,746	98,147
Less accumulated depreciation and amortization	(41,810)	(30,511)
Property, plant and equipment, net	65,936	67,636
Laboratory equipment
Property, Plant and Equipment [Line Items]
Property, plant, and equipment, gross	14,636	21,048
Computer equipment and software
Property, Plant and Equipment [Line Items]
Property, plant, and equipment, gross	2,005	1,597
Office equipment
Property, Plant and Equipment [Line Items]
Property, plant, and equipment, gross	4,767	4,323
Leasehold improvements
Property, Plant and Equipment [Line Items]
Property, plant, and equipment, gross	1,251	0
Construction-in-progress
Property, Plant and Equipment [Line Items]
Property, plant, and equipment, gross	$ 563	$ 0

Property, plant and equipment_4

Property, plant and equipment, net - Narrative (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Property, Plant and Equipment [Abstract]
Depreciation and amortization	$ 28	$ 8.2

Restricted cash - Narrative (De

Restricted cash - Narrative (Detail) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Debt and Equity Securities, FV-NI [Line Items]
Restricted cash balance	$ 52,842	$ 45,439
Letter of Credit
Debt and Equity Securities, FV-NI [Line Items]
Restricted cash balance	$ 51,200	$ 43,900

Restricted cash - Schedule of C

Restricted cash - Schedule of Collateralized Bank Account of Financial Institution (Detail) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Debt and Equity Securities, FV-NI [Line Items]
Total restricted cash	$ 52,842	$ 45,439
50 Binney Street lease
Debt and Equity Securities, FV-NI [Line Items]
Total restricted cash	40,072	40,072
Assembly Row lease
Debt and Equity Securities, FV-NI [Line Items]
Total restricted cash	2,753	2,753
Embedded lease
Debt and Equity Securities, FV-NI [Line Items]
Total restricted cash	7,632	0
Other
Debt and Equity Securities, FV-NI [Line Items]
Total restricted cash	$ 2,385	$ 2,614

Accrued expenses and other cu_3

Accrued expenses and other current liabilities - Summary of Accrued Expenses and Other Current Liabilities (Detail) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Payables and Accruals [Abstract]
Accrued CMO and CRO costs	$ 24,824	$ 17,369
Accrued employee compensation	19,972	20,095
Accrued goods and services	8,391	7,635
Accrued rebates	5,365	0
Accrued refund liability	5,600	0
Other	9,036	8,365
Total accrued expenses and other current liabilities	$ 73,188	$ 53,464

Leases - Narrative (Details)

Leases - Narrative (Details) $ in Thousands, € in Millions

1 Months Ended

3 Months Ended

12 Months Ended

13 Months Ended

22 Months Ended

24 Months Ended

Oct. 31, 2022 ft² $ / ft²

Aug. 31, 2022 USD ($)

Jul. 31, 2022 USD ($)

Dec. 31, 2021 USD ($)

Dec. 31, 2021 EUR (€)

Nov. 30, 2021 USD ($) ft² $ / ft²

Oct. 31, 2021 USD ($) ft²

Feb. 28, 2021 USD ($)

Jul. 31, 2020 USD ($)

Apr. 30, 2019 USD ($) ft² $ / ft²

Jan. 31, 2019 EUR (€)

Jun. 30, 2022 USD ($) ft²

Dec. 31, 2023 USD ($) lease_arrangement

Dec. 31, 2022 USD ($)

Dec. 31, 2023 USD ($) lease_arrangement

Mar. 31, 2018 USD ($)

Dec. 31, 2019 EUR (€)

Sep. 30, 2023 USD ($)

Nov. 30, 2016

Jun. 30, 2016

Lessee, Lease, Description [Line Items]

Lease arrangements annual rent increase percentage

3%

Number of embedded lease arrangements | lease_arrangement

6

6

Total purchase commitments

$ 54,494

$ 54,494

Prepaid expenses

14,800

$ 8,618

14,800

Finance lease amortization without alternative future use

21,200

11,200

60 Binney Street lease

Lessee, Lease, Description [Line Items]

Collateralized letter of credit

$ 13,800

Market capitalization required for release of liability

$ 900,000

Lease building space (in sq ft) | ft²

72,988

58,004

Lessee, operating lease, monthly expense

$ 600

$ 1,000

$ 800

50 Binney Street sublease

Lessee, Lease, Description [Line Items]

Collateralized letter of credit

$ 40,100

$ 40,100

Lease building space (in sq ft) | ft²

267,278

Rate of area for sublease per square feet (in dollars per sq ft) | $ / ft²

99.95

Lessee, operating lease, annual expense

$ 26,700

Lease arrangements annual rent increase percentage

3%

Annual base rent of sub-sublease

$ 29,400

Monthly sub-lease income

$ 2,600

Assembly Row lease

Lessee, Lease, Description [Line Items]

Lease building space (in sq ft) | ft²

61,180

Annual lease rent per square foot (in dollars per sq ft) | $ / ft²

45

Lease rent, annual increase percentage

2.50%

Tenant work allowance (in dollars per sq ft) | $ / ft²

160

Monthly rent expense

$ 300

Manufacturing Facility

Lessee, Lease, Description [Line Items]

Finance lease term

14 months

5 years

5 years

3 years

5 years

12 years

Milestone paid

$ 12,000

Lessee, financing lease, annual expense

$ 5,100

Termination slot fees, term

24 months

Termination labor fees terms

12 months

Finance lease not yet commenced, term

3 years

Total purchase commitments

$ 54,500

Prepaid expenses

$ 3,700

3,700

Finance lease, renewal term

3 years

Finance lease, annual maintenance and production fee | €

€ 16.5

Payment of termination fee | €

€ 1

Lessee, operating lease, maximum potential annual maintenance fees

$ 4,200

$ 5,400

Lessee, operating lease, termination notice period

18 months

18 months

Lessee, operating lease, termination notice period, after stage 5 commencement

8 months

Lease payments and deposit

$ 10,800

Milestone prepayments | €

€ 13.5

Annual suite fees, year one

$ 13,500

Annual suite fees, year two

18,000

Annual suite fees, year three

$ 18,000

Hood Park Lease

Lessee, Lease, Description [Line Items]

Lease building space (in sq ft) | ft²

42,261

Annual lease rent per square foot (in dollars per sq ft) | $ / ft²

55

Lease rent, annual increase percentage

3%

Monthly rent expense

$ 200

Leases - Summary of Operating L

Leases - Summary of Operating Lease Costs and Other Information (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Leases [Abstract]
Interest expense	$ 16,350	$ 6,324
Amortization expense	24,653	3,886
Total fixed finance lease cost	41,003	10,210
Fixed lease cost	43,272	36,122
Variable lease cost	22,960	28,161
Short-term lease cost	238	143
Total lease cost	107,473	74,636
Operating sublease income	41,165	29,369
Operating cash flows used for operating leases	28,887	14,072
Operating cash flows used for finance leases	12,924	1,551
Financing cash flows for finance leases	$ 54,367	$ 36,734
Weighted average remaining lease term - finance leases (in years)	1 year 7 months 6 days	2 years 4 months 24 days
Weighted average discount rate - finance leases	13.93%	12.52%
Weighted average remaining lease term - operating leases (in years)	7 years	7 years 9 months 18 days
Weighted average discount rate - operating leases	7.01%	7.05%

Leases - Schedule of Future Min

Leases - Schedule of Future Minimum Commitments Under Operating Leases (Details) $ in Thousands	Dec. 31, 2023 USD ($)
Operating Leases
2024	$ 34,918
2025	37,084
2026	35,719
2027	36,742
2028	37,795
2029 and thereafter	81,986
Total	264,244
Less: Imputed Interest	(56,355)
Present Value of Lease Liabilities	207,889
Financing Leases
2024	93,531
2025	34,995
2026	2,519
2027	2,519
2028	1,031
2029 and thereafter	0
Total	134,595
Less: Imputed Interest	(12,158)
Present Value of Lease Liabilities	$ 122,437

Commitments and contingencies -

Commitments and contingencies - Narrative (Detail) $ in Millions	Dec. 31, 2023 USD ($)
Commitments and Contingencies Disclosure [Abstract]
Lease period	3 years
Total purchase commitments	$ 54.5

Commitments and contingencies_2

Commitments and contingencies - Schedule of Non-cancelable Contractual Obligations (Detail) $ in Thousands	Dec. 31, 2023 USD ($)
Commitments and Contingencies Disclosure [Abstract]
2024	$ 0
2025	11,959
2026	17,655
2027	17,655
2028	7,225
2029 and thereafter	0
Total purchase commitments	$ 54,494

Equity - Narrative (Detail)

Equity - Narrative (Detail) $ / shares in Units, $ in Millions					1 Months Ended					12 Months Ended
	Dec. 22, 2023 USD ($)	Dec. 19, 2023 $ / shares shares	Jan. 23, 2023 USD ($)	Jan. 18, 2023 $ / shares shares	Dec. 31, 2023 USD ($) vote shares	Oct. 31, 2023 shares	Aug. 31, 2023 USD ($)	Jun. 30, 2022 USD ($) shares	Sep. 30, 2021 USD ($) $ / shares shares	Dec. 31, 2022 USD ($) shares	Sep. 30, 2023 shares	Jun. 30, 2023 shares	Mar. 31, 2023 shares	Sep. 30, 2022 shares	Mar. 31, 2022 shares
Subsidiary, Sale of Stock [Line Items]
Common stock, shares authorized (in shares)					250,000,000			125,000,000		125,000,000	250,000,000	250,000,000	125,000,000	125,000,000	125,000,000
Common stock, number of votes (in votes per share) | vote					1
Common stock, shares issued (in shares)					192,772,000			73,551,000		82,923,000	107,022,000	106,454,000	106,370,000	82,880,000	71,438,000
Common stock, shares outstanding (in shares)					192,772,000			73,551,000		82,923,000	107,022,000	106,454,000	106,370,000	82,880,000	71,438,000
Preferred stock, shares authorized (in shares)					5,000,000			5,000,000		5,000,000	5,000,000	5,000,000	5,000,000	5,000,000	5,000,000
Preferred Stock, shares issued (in shares)					0			0		0	0	0	0	0	0
Preferred stock, shares outstanding (in shares)					0			0		0	0	0	0	0	0
Private Placement
Subsidiary, Sale of Stock [Line Items]
Number of shares issued in transaction (in shares)						2,300,000			2,300,000	10,700,000
Common stock price per share (in dollars per share) | $ / shares									$ 16.50
Proceeds from stock offering | $									$ 75	$ 56.2
Stock issuance costs | $										$ 54.2
Private Placement | Maximum
Subsidiary, Sale of Stock [Line Items]
Proceeds from stock offering | $								$ 75
Private Placement | Pre-funded warrants
Subsidiary, Sale of Stock [Line Items]
Number of securities called by warrants (in shares)									2,300,000
Warrant price per share (in dollars per share) | $ / shares									$ 16.49
Exercise price of warrants (in dollars per share) | $ / shares									$ 0.01
At The Market Offering
Subsidiary, Sale of Stock [Line Items]
Value of shares available for issue | $							$ 125
Overallotment Option
Subsidiary, Sale of Stock [Line Items]
Number of shares issued in transaction (in shares)		12,500,000		3,000,000
Exercisable period		30 days		30 days
December Underwriting Agreement
Subsidiary, Sale of Stock [Line Items]
Number of shares issued in transaction (in shares)		83,300,000			83,300,000
Common stock price per share (in dollars per share) | $ / shares		$ 1.50
Proceeds from stock offering | $	$ 118.1				$ 118.1
January Underwriting Agreement
Subsidiary, Sale of Stock [Line Items]
Number of shares issued in transaction (in shares)				20,000,000
Common stock price per share (in dollars per share) | $ / shares				$ 6
Proceeds from stock offering | $			$ 130.5

Sale of Priority Review Vouch_2

Sale of Priority Review Vouchers (Details) - USD ($) $ in Thousands			12 Months Ended
	Jan. 05, 2023	Dec. 29, 2022	Dec. 31, 2023	Dec. 31, 2022
Asset Acquisition [Line Items]
Proceeds from sale of priority review voucher			$ 92,930	$ 102,000
Argenx BV | PRV
Asset Acquisition [Line Items]
Proceeds from sale of priority review voucher		$ 102,000
Bristol-Myers Squibb
Asset Acquisition [Line Items]
Transaction costs	$ 2,100
Bristol-Myers Squibb | PRV
Asset Acquisition [Line Items]
Proceeds from sale of priority review voucher	$ 95,000

Intangible assets - Schedule of

Intangible assets - Schedule of Finite-Lived Intangible Assets (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Finite-Lived Intangible Assets [Line Items]
Cost	$ 11,089	$ 5,000
Accumulated amortization	(651)	(132)
Impairment	0	0
Net	10,438	4,868
In-licensed rights
Finite-Lived Intangible Assets [Line Items]
Cost	11,089	5,000
Accumulated amortization	(651)	(132)
Impairment	0	0
Net	$ 10,438	$ 4,868

Intangible assets - Narrative (

Intangible assets - Narrative (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Finite-Lived Intangible Assets [Line Items]
Amortization expense	$ 0.5	$ 0.1
In-licensed rights
Finite-Lived Intangible Assets [Line Items]
Gene editing platform expected useful life	12 years

Intangible assets - Schedule _2

Intangible assets - Schedule of Finite-Lived Intangible Assets, Future Amortization Expense (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Goodwill and Intangible Assets Disclosure [Abstract]
2024	$ 926
2025	926
2026	926
2027	926
2028	926
2029 and thereafter	5,808
Net	$ 10,438	$ 4,868

Stock-based compensation - Narr

Stock-based compensation - Narrative (Detail) $ / shares in Units, shares in Thousands, $ in Thousands		1 Months Ended		12 Months Ended
	May 18, 2021 shares	Jan. 31, 2023 shares	Jan. 31, 2022 shares	Dec. 31, 2023 USD ($) $ / shares shares	Dec. 31, 2022 USD ($) $ / shares shares	Jun. 30, 2023 shares	Jun. 30, 2021 shares	Jun. 24, 2013 shares	Jun. 03, 2013 shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Increase in common stock available for issuance under 2013 plan (in shares) | shares		2,800	3,300
Stock-based compensation expense				$ 19,429	$ 35,090
Stock-based compensation capitalized into inventory				$ 1,700	$ 300
Weighted average grant date fair value of options granted (in dollars per share) | $ / shares				$ 3.24	$ 4.46
Intrinsic value of stock options exercised				$ 0	$ 0
Conversion ratio				0.3333
Stock options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense				$ 6,478	14,168
Unrecognized stock- based compensation expense related to unvested stock options, restricted stock awards and employee stock purchase plan				$ 8,700
Expected weighted-average period related to unvested stock options, restricted stock awards and employee stock purchase plan				1 year 11 months 15 days
Restricted stock units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense				$ 12,619	20,138
Unrecognized stock- based compensation expense related to unvested stock options, restricted stock awards and employee stock purchase plan				$ 18,800
Expected weighted-average period related to unvested stock options, restricted stock awards and employee stock purchase plan				2 years 11 months 1 day
Intrinsic value of restricted stock units vested				$ 5,400	6,000
Fair value of stock vested				15,200	14,000
Employee stock purchase plan and other
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common shares reserved for future issuance (in shares) | shares									200
Stock-based compensation expense				$ 332	$ 784
Increase in shares authorized (in shares) | shares							1,400
Employee stock purchase plan and other | Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation arrangement by share-based payment award, shares issued in period (less than) (in shares) | shares				100	100
2013 Stock Option and Incentive Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common shares reserved for future issuance (in shares) | shares								1,000
Percentage of automatic increase in shares reserved and available for issuance determined based on shares outstanding				4%
2023 Incentive Award Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares available for issuance (in shares) | shares				5,100		5,200
2021 Inducement Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares available for issuance (in shares) | shares	600		1,250	1,100
Award vesting period	4 years
Expiration period	10 years

Stock-based compensation - Summ

Stock-based compensation - Summary of Stock-Based Compensation Expense by Award Type (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	$ 19,429	$ 35,090
Stock options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	6,478	14,168
Restricted stock units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	12,619	20,138
Employee stock purchase plan and other
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	$ 332	$ 784

Stock-based compensation - Sche

Stock-based compensation - Schedule of Stock-Based Compensation Expense by Classification (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	$ 19,429	$ 35,090
Cost of product revenue
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	881	0
Selling, general and administrative
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	9,548	15,831
Research and development
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	$ 9,000	$ 19,259

Stock-based compensation - Assu

Stock-based compensation - Assumptions Used for the Black-Scholes Option-Pricing Model to Determine the Per Share Weighted Average Fair Value for Options Granted (Detail)	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Share-Based Payment Arrangement [Abstract]
Expected volatility	70.90%	66.40%
Expected term (in years)	6 years 1 month 6 days	6 years
Risk-free interest rate	4.10%	1.90%
Expected dividend yield	0%	0%

Stock-based compensation - Su_2

Stock-based compensation - Summary of Stock Option Activity Under Plan (Detail) $ / shares in Units, shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2023 USD ($) $ / shares shares
Shares (in thousands)
Outstanding at beginning of period (in shares) | shares	2,668
Granted (in shares) | shares	2,077
Exercised (in shares) | shares	(3)
Canceled or forfeited (in shares) | shares	(515)
Outstanding at end of period (in shares) | shares	4,227
Exercisable at end of period (in shares) | shares	1,469
Vested and expected to vest at end of period (in shares) | shares	4,227
Weighted- average exercise price per share
Outstanding at beginning of period (in dollars per share) | $ / shares	$ 24.38
Granted (in dollars per share) | $ / shares	4.89
Exercised (in dollars per share) | $ / shares	2.74
Canceled or forfeited (in dollars per share) | $ / shares	29.55
Outstanding at end of period (in dollars per share) | $ / shares	14.16
Exercisable at end of period (in dollars per share) | $ / shares	28.80
Vested and expected to vest at end of period (in dollars per share) | $ / shares	$ 14.16
Weighted- average contractual life (in years)
Outstanding at end of period	8 years 21 days
Exercisable at end of period	6 years 6 months 14 days
Vested and expected to vest at end of period	8 years 21 days
Aggregate intrinsic value (in thousands)
Outstanding at end of period | $	$ 0
Exercisable at end of period | $	0
Vested and expected to vest at end of period | $	$ 0

Stock-based compensation - Su_3

Stock-based compensation - Summary of Restricted Stock Units (Detail) - Restricted stock units shares in Thousands	12 Months Ended
	Dec. 31, 2023 $ / shares shares
Shares (in thousands)
Unvested balance at beginning of period (in shares) | shares	2,415
Granted (in shares) | shares	3,369
Vested (in shares) | shares	(1,057)
Forfeited (in shares) | shares	(520)
Unvested balance at end of period (in shares) | shares	4,207
Weighted-average grant date fair value
Unvested balance at beginning of period (in dollars per share) | $ / shares	$ 11.44
Granted (in dollars per share) | $ / shares	4.76
Vested (in dollars per share) | $ / shares	14.35
Forfeited (in dollars per share) | $ / shares	8.09
Unvested balance at end of period (in dollars per share) | $ / shares	$ 6.08

401(k) Savings plan - Narrative

401(k) Savings plan - Narrative (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Retirement Benefits [Abstract]
Expenses related to 401(k) plan	$ 3.1	$ 2.7

Income taxes - Schedule of Comp

Income taxes - Schedule of Components of Loss Before Income Taxes (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Income Tax Disclosure [Abstract]
U.S.	$ (213,306)	$ (230,160)
Foreign	1,267	(65)
Loss before income taxes	$ (212,039)	$ (230,225)

Income taxes - Summary of Provi

Income taxes - Summary of Provision for (Benefit from) Income Taxes (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Current:
Federal	$ 0	$ 0
State	0	0
Foreign	(126)	117
Deferred:
Federal	0	0
State	0	0
Foreign	0	0
Total income tax expense (benefit)	$ (126)	$ 117

Income taxes - Reconciliation o

Income taxes - Reconciliation of Income Tax Provision (Benefit) (Detail)	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Income Tax Disclosure [Abstract]
Federal income tax expense at statutory rate	21%	21%
State income tax, net of federal benefit	7.30%	5.20%
Permanent differences	0.60%	(0.10%)
Stock-based compensation	(3.60%)	(9.30%)
Research and development credit	5.80%	8.30%
Leases	5.40%	34.40%
Right-of-use assets	0%	(26.10%)
Fixed assets	(2.70%)	(7.20%)
Foreign differential	0%	0.30%
Other	0.90%	(0.60%)
Change in valuation allowance	(34.60%)	(26.00%)
Effective income tax rate (expense) benefit	0.10%	(0.10%)

Income taxes - Narrative (Detai

Income taxes - Narrative (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Components Of Income Tax Expense Benefit [Line Items]
Income tax expense (benefit)	$ (126,000)	$ 117,000
Effective income tax rate	0.10%	(0.10%)
Approximately valuation allowance increased	$ 73,300,000
Operating loss carryforwards, without expiration dates	2,000,000,000
Operating loss carryforwards, with expiration dates	700,000,000
Capital loss carryforwards	4,200,000	$ 4,200,000
Income tax examination, penalties and interest accrued	$ 0	0
Research Tax Credit Carryforward
Components Of Income Tax Expense Benefit [Line Items]
Limitations on use of net operating losses and tax credit carryforwards, period	3 years
Limitations on use of net operating losses and tax credit carryforwards, percentage	50%
U.S.
Components Of Income Tax Expense Benefit [Line Items]
Operating loss carryforwards	$ 2,700,000,000	2,700,000,000
U.S. | Research Tax Credit Carryforward
Components Of Income Tax Expense Benefit [Line Items]
Tax credit carryforward amount	299,500,000	285,600,000
State and Local Jurisdiction
Components Of Income Tax Expense Benefit [Line Items]
Operating loss carryforwards	2,500,000,000	2,500,000,000
State and Local Jurisdiction | Research Tax Credit Carryforward
Components Of Income Tax Expense Benefit [Line Items]
Tax credit carryforward amount	$ 18,300,000	$ 18,500,000

Income taxes - Components of De

Income taxes - Components of Deferred Tax Assets and Liabilities (Detail) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Deferred tax assets:
U.S. net operating loss carryforwards (federal and state)	$ 726,021	$ 713,557
Tax credit carryforwards (federal and state)	313,963	300,236
Capitalized license fees and research and development expenses	2,079	1,831
Capitalized research and development expenses under Section 174	91,306	54,885
Stock-based compensation	9,847	11,686
Lease liabilities	100,288	98,296
Accruals and other	20,336	17,325
Total deferred tax assets	1,263,840	1,197,816
Right-of-use assets	(54,976)	(61,388)
Fixed assets	(16,701)	(17,536)
Less valuation allowance	(1,192,163)	(1,118,892)
Net deferred taxes	$ 0	$ 0

Income taxes - Reconciliation_2

Income taxes - Reconciliation of Unrecognized Tax Benefits (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Balance as of beginning of period	$ 23,493	$ 21,956
Increases (decreases) for tax positions related to current period	944	1,582
Increases (decreases) for tax positions related to prior periods		(45)
Increases (decreases) for tax positions related to prior periods	101
Balance as of end of period	$ 24,538	$ 23,493

Reduction in workforce - Narrat

Reduction in workforce - Narrative (Details) - USD ($) $ in Thousands	1 Months Ended	6 Months Ended	12 Months Ended
	Apr. 30, 2022	Sep. 30, 2022	Dec. 31, 2023	Dec. 31, 2022
Restructuring Cost and Reserve [Line Items]
Payments for restructuring				$ 4,940
Restructuring expense			$ 0	4,940
April 2022 Reduction
Restructuring Cost and Reserve [Line Items]
Plans to reduce workforce, as a percent	30%	30%
Payments for restructuring		$ 4,900		4,940
Restructuring expense				$ 4,940

Reduction in workforce - Accrue

Reduction in workforce - Accrued Liabilities Activity (Details) - USD ($) $ in Thousands	6 Months Ended	12 Months Ended
	Sep. 30, 2022	Dec. 31, 2023	Dec. 31, 2022
Restructuring Cost and Reserve [Line Items]
Restructuring Expenses		$ 0	$ 4,940
Amounts paid			(4,940)
April 2022 Reduction
Restructuring Cost and Reserve [Line Items]
Restructuring Expenses			4,940
Amounts paid	$ (4,900)		$ (4,940)

Net loss per share - Common Sto

Net loss per share - Common Stock Equivalents Excluded from Calculation of Diluted Net Loss Per Share (Detail) - shares shares in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Common stock equivalents excluded from the calculation of diluted net loss per share (in shares)	22,639	7,016
Outstanding stock options
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Common stock equivalents excluded from the calculation of diluted net loss per share (in shares)	5,860	4,429
Restricted stock units
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Common stock equivalents excluded from the calculation of diluted net loss per share (in shares)	4,239	2,524
Warrants
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Common stock equivalents excluded from the calculation of diluted net loss per share (in shares)	12,450	0
ESPP shares and other
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Common stock equivalents excluded from the calculation of diluted net loss per share (in shares)	90	63

Net loss per share - Narrative

Net loss per share - Narrative (Details) - $ / shares	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Earnings Per Share [Abstract]
Net loss per share applicable to common stockholders - basic (in dollars per share)	$ 1.93	$ 2.93
Net loss per share applicable to common stockholders - diluted (in dollars per share)	$ 1.93	$ 2.93

Quarterly Financial Informati_3

Quarterly Financial Information (Unaudited) - Consolidated Balance Sheets (Details) - USD ($) $ / shares in Units, $ in Thousands	Dec. 31, 2023	Sep. 30, 2023	Jun. 30, 2023	Mar. 31, 2023	Dec. 31, 2022	Sep. 30, 2022	Jun. 30, 2022	Mar. 31, 2022	Dec. 31, 2021
Current assets:
Cash and cash equivalents	$ 221,755				$ 113,006
Marketable securities	0				67,321
Prepaid expenses	14,800				8,618
Inventory	22,919				0
Receivables and other current assets	22,211				14,627
Total current assets	281,685				203,572
Marketable securities	0				1,414
Property, plant and equipment, net	65,936				67,636
Goodwill	5,646				5,646
Intangible assets, net	10,438				4,868
Operating lease right-of-use assets	201,113				230,885
Restricted cash and other non-current assets	54,343				55,793
Total assets	619,161				569,814
Current liabilities:
Accounts payable	18,498				14,867
Accrued expenses and other current liabilities	73,188				53,464
Operating lease liability, current portion	21,202				27,594
Finance lease liability, current portion	84,705				60,654
Total current liabilities	200,113				156,579
Operating lease liability, net of current portion	186,687				209,128
Finance lease liability, net of current portion	37,732				69,682
Other non-current liabilities	92				92
Total liabilities	424,624				435,481
Commitments and contingencies Note 12
Stockholders' equity:
Preferred stock, $0.01 par value, 5,000 shares authorized; 0 shares issued and    outstanding at December 31, 2023 and December 31, 2022	0				0
Common stock, $0.01 par value, 250,000 and 125,000 shares authorized; 192,772 and 82,923 shares issued and outstanding at December 31, 2023 and December 31, 2022, respectively	1,905				830
Additional paid-in capital	4,454,756				4,185,988
Accumulated other comprehensive loss	(1,796)				(4,070)
Accumulated deficit	(4,260,328)				(4,048,415)
Total stockholders' equity	194,537				134,333				$ 276,129
Total liabilities and stockholders' equity	$ 619,161				$ 569,814
Preferred stock, par value per share (in dollars per share)	$ 0.01	$ 0.01	$ 0.01	$ 0.01	$ 0.01	$ 0.01	$ 0.01	$ 0.01
Preferred stock, shares authorized (in shares)	5,000,000	5,000,000	5,000,000	5,000,000	5,000,000	5,000,000	5,000,000	5,000,000
Preferred stock, shares issued (in shares)	0	0	0	0	0	0	0	0
Preferred stock, shares outstanding (in shares)	0	0	0	0	0	0	0	0
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01	$ 0.01	$ 0.01	$ 0.01	$ 0.01	$ 0.01	$ 0.01
Common stock, shares authorized (in shares)	250,000,000	250,000,000	250,000,000	125,000,000	125,000,000	125,000,000	125,000,000	125,000,000
Common stock, shares issued (in shares)	192,772,000	107,022,000	106,454,000	106,370,000	82,923,000	82,880,000	73,551,000	71,438,000
Common stock, shares outstanding (in shares)	192,772,000	107,022,000	106,454,000	106,370,000	82,923,000	82,880,000	73,551,000	71,438,000
Previously Reported
Current assets:
Cash and cash equivalents		$ 165,347	$ 172,872	$ 239,045	$ 113,006	$ 66,478	$ 81,499	$ 106,260
Marketable securities		8,946	72,431	79,212	67,321	73,155	51,010	105,328
Accounts receivable		23,000
Prepaid expenses		11,431	13,597	13,466	8,374	8,270	24,473	31,798
Inventory		20,969	13,642	3,809
Receivables and other current assets		17,383	15,435	15,539	10,787	12,535	10,476	11,531
Total current assets		247,076	287,977	351,071	199,488	160,438	167,458	254,917
Marketable securities					1,414	1,407	40,641	55,049
Property, plant and equipment, net		9,972	10,227	8,718	9,362	11,535	14,566	11,234
Goodwill		5,646	5,646	5,646	5,646	5,646	5,646	5,646
Intangible assets, net		5,368	5,490	5,613	4,868	0
Operating lease right-of-use assets		294,717	302,849	270,153	281,996	288,684	292,731	111,897
Restricted cash and other non-current assets		50,829	51,204	51,535	52,128	52,388	52,550	52,328
Total assets		613,608	663,393	692,736	554,902	520,098	573,592	491,071
Current liabilities:
Accounts payable		19,852	10,894	19,235	25,092	18,622	24,865	28,350
Deferred revenue		9,653
Accrued expenses and other current liabilities		57,768	56,531	45,294	51,985	64,314	75,550	89,032
Operating lease liability, current portion		71,684	67,591	51,404	51,160	43,791	48,446	25,510
Finance lease liability, current portion		0	0	0	0	0	0	0
Total current liabilities		158,957	135,016	115,933	128,237	126,727	148,861	142,892
Operating lease liability, net of current portion		232,023	239,266	221,971	230,230	234,422	244,522	84,828
Finance lease liability, net of current portion		0	0	0	0	0	0	0
Other non-current liabilities		92	92	92	92	92	93	92
Total liabilities		391,072	374,374	337,996	358,559	361,241	393,476	227,812
Stockholders' equity:
Preferred stock, $0.01 par value, 5,000 shares authorized; 0 shares issued and    outstanding at December 31, 2023 and December 31, 2022		0	0	0	0	0	0	0
Common stock, $0.01 par value, 250,000 and 125,000 shares authorized; 192,772 and 82,923 shares issued and outstanding at December 31, 2023 and December 31, 2022, respectively		1,071	1,065	1,064	830	829	735	714
Additional paid-in capital		4,333,594	4,328,489	4,322,025	4,186,086	4,181,393	4,126,012	4,109,081
Accumulated other comprehensive loss		(2,227)	(2,364)	(3,086)	(4,070)	(4,630)	(4,416)	(4,459)
Accumulated deficit		(4,109,902)	(4,038,171)	(3,965,263)	(3,986,503)	(4,018,735)	(3,942,215)	(3,842,077)
Total stockholders' equity		222,536	289,019	354,740	196,343	158,857	180,116	263,259	374,277
Total liabilities and stockholders' equity		613,608	663,393	692,736	554,902	520,098	573,592	491,071
Revision of Prior Period, Error Correction, Adjustment | Adjustments to Leases
Current assets:
Cash and cash equivalents		0	0	0	0	0	0	0
Marketable securities		0	0	0	0	0	0	0
Accounts receivable		0
Prepaid expenses		(2,040)	(2,162)	(2,082)	244	55	(667)	(1,549)
Inventory		(3,205)	(1,838)	(610)
Receivables and other current assets		3,538	3,659	3,374	3,840	2,425	2,997	198
Total current assets		(1,707)	(341)	682	4,084	2,480	2,330	(1,351)
Marketable securities					0	0	0	0
Property, plant and equipment, net		63,398	51,722	53,223	58,585	(777)	(688)	(599)
Goodwill		0	0	0	0	0	0	0
Intangible assets, net		0	0	0	0	0
Operating lease right-of-use assets		(87,796)	(86,929)	(46,690)	(51,111)	(56,750)	(54,005)	(61,082)
Restricted cash and other non-current assets		3,665	3,665	3,665	3,665	3,665	3,665	3,665
Total assets		(22,440)	(31,883)	10,880	15,223	(51,382)	(48,698)	(59,367)
Current liabilities:
Accounts payable		(3,042)	(1,081)	(2,522)	(10,225)	(2,898)	(2,846)	(4,937)
Deferred revenue		0
Accrued expenses and other current liabilities		572	(599)	1,017	(520)	(13,432)	(12,189)	(15,597)
Operating lease liability, current portion		(46,160)	(42,427)	(24,784)	(23,566)	(20,322)	(22,583)	(9,262)
Finance lease liability, current portion		85,208	55,706	58,747	60,654	41,264	47,219	55,995
Total current liabilities		36,578	11,599	32,458	26,343	4,612	9,601	26,199
Operating lease liability, net of current portion		(39,456)	(40,930)	(18,176)	(21,102)	(24,069)	(27,634)	(46,407)
Finance lease liability, net of current portion		50,146	50,017	58,649	69,682	31,036	36,550	41,315
Other non-current liabilities		0	0	0	0	0	0	0
Total liabilities		47,268	20,686	72,931	74,923	11,579	18,517	21,107
Commitments and contingencies Note 12
Stockholders' equity:
Preferred stock, $0.01 par value, 5,000 shares authorized; 0 shares issued and    outstanding at December 31, 2023 and December 31, 2022		0	0	0	0	0	0	0
Common stock, $0.01 par value, 250,000 and 125,000 shares authorized; 192,772 and 82,923 shares issued and outstanding at December 31, 2023 and December 31, 2022, respectively		0	0	0	0	0	0	0
Additional paid-in capital		0	0	0	0	0	0	0
Accumulated other comprehensive loss		0	0	0	0	0	0	0
Accumulated deficit		(69,708)	(52,569)	(62,051)	(59,700)	(62,961)	(67,215)	(80,474)
Total stockholders' equity		(69,708)	(52,569)	(62,051)	(59,700)	(62,961)	(67,215)	(80,474)	(95,634)
Total liabilities and stockholders' equity		(22,440)	(31,883)	10,880	15,223	(51,382)	(48,698)	(59,367)
Revision of Prior Period, Error Correction, Adjustment | Other Adjustments
Current assets:
Cash and cash equivalents		0	0	0	0	0	0	0
Marketable securities		0	0	0	0	0	0	0
Accounts receivable		(8,400)
Prepaid expenses		0	0	0	0	0	0	0
Inventory		602	602	0
Receivables and other current assets				(2,800)	0	0	0	0
Total current assets		(7,798)	602	(2,800)	0	0	0	0
Marketable securities					0	0	0	0
Property, plant and equipment, net		(280)	(235)	(270)	(311)	(358)	(406)	(459)
Goodwill		0	0	0	0	0	0	0
Intangible assets, net		0	0	0	0	4,972
Operating lease right-of-use assets				0		0	0	0
Restricted cash and other non-current assets		0	0	0	0	0	0	0
Total assets		(8,078)	367	(3,070)	(311)	4,614	(406)	(459)
Current liabilities:
Accounts payable		316	0	0	0	0	0	0
Deferred revenue		(8,400)
Accrued expenses and other current liabilities		0	1,999	(801)	1,999	1,998	1,999	1,999
Operating lease liability, current portion		0	0		0	0	0	0
Finance lease liability, current portion		0	0	0	0	0	0	0
Total current liabilities		(8,084)	1,999	(801)	1,999	1,998	1,999	1,999
Operating lease liability, net of current portion		0			0	0	0	0
Finance lease liability, net of current portion		0	0	0	0	0	0	0
Other non-current liabilities		0	0	0	0	0	0	0
Total liabilities		(8,084)	1,999	(801)	1,999	1,998	1,999	1,999
Commitments and contingencies Note 12
Stockholders' equity:
Preferred stock, $0.01 par value, 5,000 shares authorized; 0 shares issued and    outstanding at December 31, 2023 and December 31, 2022		0	0	0	0	0	0	0
Common stock, $0.01 par value, 250,000 and 125,000 shares authorized; 192,772 and 82,923 shares issued and outstanding at December 31, 2023 and December 31, 2022, respectively		0	0	0	0	0	0	0
Additional paid-in capital		(98)	(98)	(98)	(98)	(2,043)	(1,854)	(1,384)
Accumulated other comprehensive loss		0	0	0	0	0	0	0
Accumulated deficit		104	(1,534)	(2,171)	(2,212)	4,659	(551)	(1,074)
Total stockholders' equity		6	(1,632)	(2,269)	(2,310)	2,616	(2,405)	(2,458)	(2,514)
Total liabilities and stockholders' equity		(8,078)	367	(3,070)	(311)	4,614	(406)	(459)
As Restated
Current assets:
Cash and cash equivalents		165,347	172,872	239,045		66,478	81,499	106,260
Marketable securities		8,946	72,431	79,212		73,155	51,010	105,328
Accounts receivable		14,600
Prepaid expenses		9,391	11,435	11,384		8,325	23,806	30,249
Inventory		18,366	12,406	3,199
Receivables and other current assets		20,921	19,094	16,113		14,960	13,473	11,729
Total current assets		237,571	288,238	348,953		162,918	169,788	253,566
Marketable securities						1,407	40,641	55,049
Property, plant and equipment, net		73,090	61,714	61,671		10,400	13,472	10,176
Goodwill		5,646	5,646	5,646		5,646	5,646	5,646
Intangible assets, net		5,368	5,490	5,613		4,972
Operating lease right-of-use assets		206,921	215,920	223,463		231,934	238,726	50,815
Restricted cash and other non-current assets		54,494	54,869	55,200		56,053	56,215	55,993
Total assets		583,090	631,877	700,546		473,330	524,488	431,245
Current liabilities:
Accounts payable		17,126	9,813	16,713		15,724	22,019	23,413
Deferred revenue		1,253
Accrued expenses and other current liabilities		58,340	57,931	45,510		52,880	65,360	75,434
Operating lease liability, current portion		25,524	25,164	26,620		23,469	25,863	16,248
Finance lease liability, current portion		85,208	55,706	58,747		41,264	47,219	55,995
Total current liabilities		187,451	148,614	147,590		133,337	160,461	171,090
Operating lease liability, net of current portion		192,567	198,336	203,795		210,353	216,888	38,421
Finance lease liability, net of current portion		50,146	50,017	58,649		31,036	36,550	41,315
Other non-current liabilities		92	92	92		92	93	92
Total liabilities		430,256	397,059	410,126		374,818	413,992	250,918
Commitments and contingencies Note 12
Stockholders' equity:
Preferred stock, $0.01 par value, 5,000 shares authorized; 0 shares issued and    outstanding at December 31, 2023 and December 31, 2022		0	0	0		0	0	0
Common stock, $0.01 par value, 250,000 and 125,000 shares authorized; 192,772 and 82,923 shares issued and outstanding at December 31, 2023 and December 31, 2022, respectively		1,071	1,065	1,064		829	735	714
Additional paid-in capital		4,333,496	4,328,391	4,321,927		4,179,350	4,124,158	4,107,697
Accumulated other comprehensive loss		(2,227)	(2,364)	(3,086)		(4,630)	(4,416)	(4,459)
Accumulated deficit		(4,179,506)	(4,092,274)	(4,029,485)		(4,077,037)	(4,009,981)	(3,923,625)
Total stockholders' equity		152,834	234,818	290,420	$ 134,333	98,512	110,496	180,327	$ 276,129
Total liabilities and stockholders' equity		$ 583,090	$ 631,877	$ 700,546		$ 473,330	$ 524,488	$ 431,245

Quarterly Financial Informati_4

Quarterly Financial Information (Unaudited) - Statements of Operations and Comprehensive Loss (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended						6 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2023	Jun. 30, 2023	Mar. 31, 2023	Sep. 30, 2022	Jun. 30, 2022	Mar. 31, 2022	Jun. 30, 2023	Jun. 30, 2022	Sep. 30, 2023	Sep. 30, 2022	Dec. 31, 2023	Dec. 31, 2022
Revenue:
Revenue											$ 29,065	$ 2,739
Other revenue											432	858
Total revenues											29,497	3,597
Operating expenses:
Selling, general and administrative											165,510	140,326
Research and development											167,652	200,439
Cost of product revenue											33,527	10,077
Gross margin											(4,030)	(6,480)
Restructuring expense											0	4,940
Total operating expenses											333,162	345,705
Loss on fixed assets disposal											92,930	102,000
Loss from operations											(244,262)	(250,185)
Interest income											9,869	1,032
Interest expense											(16,353)	(6,322)
Other income, net											38,707	25,250
Loss before income taxes											(212,039)	(230,225)
Income tax benefit (expense)											126	(117)
Net loss											$ (211,913)	$ (230,342)
Net income (loss) per share - basic (in dollars per share)											$ (1.93)	$ (2.93)
Net income (loss) per share - diluted (in dollars per share)											$ (1.93)	$ (2.93)
Weighted-average number of common shares used in computing net loss per share - basic (in shares)											109,825	78,585
Weighted-average number of common shares used in computing net loss per share - diluted (in shares)											109,825	78,585
Other comprehensive income (loss):
Other comprehensive income (loss)											$ 2,274	$ (1,159)
Comprehensive Income (Loss), Net of Tax, Attributable to Parent											(209,639)	(231,501)
Other comprehensive income (loss), tax	$ 0	$ 0	$ 0	$ 0	$ 0	$ 0	$ 0	$ 0	$ 0	$ 0	$ 0	0
Previously Reported
Revenue:
Revenue	12,281	6,837	2,296	0	1,331	1,408	9,133	2,739	21,414	2,739		2,739
Other revenue	111	53	85	71	188	537	138	725	249	795		858
Total revenues	12,392	6,890	2,381	71	1,519	1,945	9,271	3,464	21,663	3,534		3,597
Operating expenses:
Selling, general and administrative	40,703	40,349	37,354	33,402	36,694	36,106	77,703	72,800	118,406	106,201		136,908
Research and development	45,463	42,274	46,144	53,149	63,841	77,875	88,418	141,716	133,881	194,864		240,764
Cost of product revenue	10,955	9,564	3,376	0	1,745	8,310	12,940	10,055	23,895	10,056		10,077
Gross margin	1,437	(2,674)	(995)	71	(226)	(6,365)	(3,669)	(6,591)	(2,232)	(6,522)		(6,480)
Restructuring expense				(1,699)	6,639			6,639		4,940		4,940
Total operating expenses	86,166	82,623	83,498	84,852	107,174	113,981	166,121	221,155	252,287	306,005		382,612
Loss on fixed assets disposal			92,930				92,930		92,930			102,000
Loss from operations	(84,729)	(85,297)	8,437	(84,781)	(107,400)	(120,346)	(76,860)	(227,746)	(161,589)	(312,527)		(287,092)
Interest income	2,454	2,679	2,828	383	174	106	5,507	280	7,961	663		1,032
Interest expense	0	0	(3)	0	0	0	(3)	0	(3)	0		0
Other income, net	10,544	9,630	9,978	7,885	7,088	(1,912)	19,608	5,176	30,152	13,061		19,599
Loss before income taxes	(71,731)	(72,988)	21,240	(76,513)	(100,138)	(122,152)	(51,748)	(222,290)	(123,479)	(298,803)		(266,461)
Income tax benefit (expense)	0	80	0	(7)	0	0	80	0	80	(7)		(117)
Net loss	$ (71,731)	$ (72,908)	$ 21,240	$ (76,520)	$ (100,138)	$ (122,152)	$ (51,668)	$ (222,290)	$ (123,399)	$ (298,810)		$ (266,578)
Net income (loss) per share - basic (in dollars per share)	$ (0.66)	$ (0.67)	$ 0.21	$ (0.94)	$ (1.36)	$ (1.66)	$ (0.49)	$ (3.02)	$ (1.15)	$ (3.91)		$ (3.39)
Net income (loss) per share - diluted (in dollars per share)	$ (0.66)	$ (0.67)	$ 0.21	$ (0.94)	$ (1.36)	$ (1.66)	$ (0.49)	$ (3.02)	$ (1.15)	$ (3.91)		$ (3.39)
Weighted-average number of common shares used in computing net loss per share - basic (in shares)	109,098	108,685	102,920	81,543	73,767	73,688	105,819	73,727	106,924	76,361		78,585
Weighted-average number of common shares used in computing net loss per share - diluted (in shares)	109,098	108,685	103,303	81,543	73,767	73,688	105,819	73,727	106,924	76,361		78,585
Other comprehensive income (loss):
Other comprehensive income (loss)	$ 137	$ 722	$ 984	$ (214)	$ 43	$ (1,548)	$ 1,706	$ (1,505)	$ 1,843	$ (1,719)		$ (1,159)
Comprehensive Income (Loss), Net of Tax, Attributable to Parent	(71,594)	(72,186)	22,224	(76,734)	(100,095)	(123,700)	(49,962)	(223,795)	(121,556)	(300,529)		(267,737)
Revision of Prior Period, Error Correction, Adjustment | Adjustments to Leases
Revenue:
Revenue	0	0	0	0	0	0	0	0	0	0		0
Other revenue	0	0	0	0	0	0	0	0	0	0		0
Total revenues	0	0	0	0	0	0	0	0	0	0		0
Operating expenses:
Selling, general and administrative	68	113	113	273	(314)	(147)	226	(461)	294	(188)		3,516
Research and development	14,757	(10,189)	(4,516)	(2,923)	(12,355)	(15,511)	(14,705)	(27,866)	52	(30,789)		(40,121)
Cost of product revenue	(1,829)	(2,867)	2,136	0	0	0	(731)	0	(2,560)	0		0
Gross margin	1,829	2,867	(2,136)	0	0	0	731	0	2,560	0		0
Restructuring expense				0	0			0		0		0
Total operating expenses	14,825	(10,076)	(4,403)	(2,650)	(12,669)	(15,658)	(14,479)	(28,327)	346	(30,977)		(36,605)
Loss on fixed assets disposal			0				0		0			0
Loss from operations	(12,996)	12,943	2,267	2,650	12,669	15,658	15,210	28,327	2,214	30,977		36,605
Interest income	0	0	0	0	0	0	0	0	0	0		0
Interest expense	(4,311)	(3,750)	(4,267)	(1,552)	(922)	(1,028)	(8,017)	(1,950)	(12,328)	(3,502)		(6,322)
Other income, net	168	289	(351)	3,156	1,512	530	(62)	2,042	106	5,198		5,651
Loss before income taxes	(17,139)	9,482	(2,351)	4,254	13,259	15,160	7,131	28,419	(10,008)	32,673		35,934
Income tax benefit (expense)	0	0	0	0	0	0		0	0	0		0
Net loss	$ (17,139)	$ 9,482	$ (2,351)	$ 4,254	$ 13,259	$ 15,160	$ 7,131	$ 28,419	$ (10,008)	$ 32,673		$ 35,934
Net income (loss) per share - basic (in dollars per share)	$ (0.16)	$ 0.09	$ (0.02)	$ 0.05	$ 0.18	$ 0.21	$ 0.07	$ 0.39	$ (0.09)	$ 0.43		$ 0.46
Net income (loss) per share - diluted (in dollars per share)	$ (0.16)	$ 0.09	$ (0.02)	$ 0.05	$ 0.18	$ 0.21	$ 0.07	$ 0.39	$ (0.09)	$ 0.43		$ 0.46
Weighted-average number of common shares used in computing net loss per share - basic (in shares)	0	0	0	0	0	0	0	0	0	0		0
Weighted-average number of common shares used in computing net loss per share - diluted (in shares)	0	0	0	0	0	0	0	0	0	0		0
Other comprehensive income (loss):
Other comprehensive income (loss)	$ 0	$ 0	$ 0	$ 0	$ 0	$ 0	$ 0	$ 0	$ 0	$ 0		$ 0
Comprehensive Income (Loss), Net of Tax, Attributable to Parent	(17,139)	9,482	(2,351)	4,254	13,259	15,160	7,131	28,419	(10,008)	32,673		35,934
Revision of Prior Period, Error Correction, Adjustment | Other Adjustments
Revenue:
Revenue	0	0	0	0	0	0	0	0	0	0		0
Other revenue	0	0	0	0	0	0	0	0	0	0		0
Total revenues	0	0	0	0	0	0	0	0	0	0		0
Operating expenses:
Selling, general and administrative	0	0	0	4	(261)	(510)	0	(771)	0	(767)		(98)
Research and development	(1,719)	(637)	(41)	(5,214)	(262)	(930)	(678)	(1,192)	(2,397)	(6,406)		(204)
Cost of product revenue	0	0	0	0	0	0	0	0	0	0		0
Gross margin	0	0	0	0	0	0	0	0	0	0		0
Restructuring expense				0	0			0		0		0
Total operating expenses	(1,719)	(637)	(41)	(5,210)	(523)	(1,440)	(678)	(1,963)	(2,397)	(7,173)		(302)
Loss on fixed assets disposal			0				0		0			0
Loss from operations	1,719	637	41	5,210	523	1,440	678	1,963	2,397	7,173		302
Interest income	0	0	0	0	0	0	0	0	0	0		0
Interest expense	0	0	0	0	0	0	0	0	0	0		0
Other income, net	(81)	0	0	0	0	0	0	0	(81)	0		0
Loss before income taxes	1,638	637	41	5,210	523	1,440	678	1,963	2,316	7,173		302
Income tax benefit (expense)	0	0	0	0	0	0	0	0	0	0		0
Net loss	$ 1,638	$ 637	$ 41	$ 5,210	$ 523	$ 1,440	$ 678	$ 1,963	$ 2,316	$ 7,173		$ 302
Net income (loss) per share - basic (in dollars per share)	$ 0.02	$ 0.01	$ 0	$ 0.06	$ 0.01	$ 0.02	$ 0.01	$ 0.03	$ 0.02	$ 0.09		$ 0
Net income (loss) per share - diluted (in dollars per share)	$ 0.02	$ 0.01	$ 0	$ 0.06	$ 0.01	$ 0.02	$ 0.01	$ 0.03	$ 0.02	$ 0.09		$ 0
Weighted-average number of common shares used in computing net loss per share - basic (in shares)	0	0	0	0	0	0	0	0	0	0		0
Weighted-average number of common shares used in computing net loss per share - diluted (in shares)	0	0	0	0	0	0	0	0	0	0		0
Other comprehensive income (loss):
Other comprehensive income (loss)	$ 0	$ 0	$ 0	$ 0	$ 0	$ 0	$ 0	$ 0	$ 0	$ 0		$ 0
Comprehensive Income (Loss), Net of Tax, Attributable to Parent	1,638	637	41	5,210	523	1,440	678	1,963	2,316	7,173		$ 302
As Restated
Revenue:
Revenue	12,281	6,837	2,296	0	1,331	1,408	9,133	2,739	21,414	2,739
Other revenue	111	53	85	71	188	537	138	725	249	795
Total revenues	12,392	6,890	2,381	71	1,519	1,945	9,271	3,464	21,663	3,534
Operating expenses:
Selling, general and administrative	40,771	40,462	37,467	33,679	36,119	35,449	77,929	71,568	118,700	105,246
Research and development	58,501	31,448	41,587	45,012	51,224	61,434	73,035	112,658	131,536	157,669
Cost of product revenue	9,126	6,697	5,512	0	1,745	8,310	12,209	10,055	21,335	10,056
Gross margin	3,266	193	(3,131)	71	(226)	(6,365)	(2,938)	(6,591)	328	(6,522)
Restructuring expense				(1,699)	6,639			6,639		4,940
Total operating expenses	99,272	71,910	79,054	76,992	93,982	96,883	150,964	190,865	250,236	267,855
Loss on fixed assets disposal			92,930				92,930		92,930
Loss from operations	(96,006)	(71,717)	10,745	(76,921)	(94,208)	(103,248)	(60,972)	(197,456)	(156,978)	(274,377)
Interest income	2,454	2,679	2,828	383	174	106	5,507	280	7,961	663
Interest expense	(4,311)	(3,750)	(4,270)	(1,552)	(922)	(1,028)	(8,020)	(1,950)	(12,331)	(3,502)
Other income, net	10,631	9,919	9,627	11,041	8,600	(1,382)	19,546	7,218	30,177	18,259
Loss before income taxes	(87,232)	(62,869)	18,930	(67,049)	(86,356)	(105,552)	(43,939)	(191,908)	(131,171)	(258,957)
Income tax benefit (expense)	0	80	0	(7)	0	0	80	0	80	(7)
Net loss	$ (87,232)	$ (62,789)	$ 18,930	$ (67,056)	$ (86,356)	$ (105,552)	$ (43,859)	$ (191,908)	$ (131,091)	$ (258,964)
Net income (loss) per share - basic (in dollars per share)	$ (0.80)	$ (0.58)	$ 0.18	$ (0.82)	$ (1.17)	$ (1.43)	$ (0.41)	$ (2.60)	$ (1.23)	$ (3.39)
Net income (loss) per share - diluted (in dollars per share)	$ (0.80)	$ (0.58)	$ 0.18	$ (0.82)	$ (1.17)	$ (1.43)	$ (0.41)	$ (2.60)	$ (1.23)	$ (3.39)
Weighted-average number of common shares used in computing net loss per share - basic (in shares)	109,098	108,685	102,920	81,543	73,767	73,688	105,819	73,727	106,924	76,361
Weighted-average number of common shares used in computing net loss per share - diluted (in shares)	109,098	108,685	103,303	81,543	73,767	73,688	105,819	73,727	106,924	76,361
Other comprehensive income (loss):
Other comprehensive income (loss)	$ 137	$ 722	$ 984	$ (214)	$ 43	$ (1,548)	$ 1,706	$ (1,505)	$ 1,843	$ (1,719)
Comprehensive Income (Loss), Net of Tax, Attributable to Parent	$ (87,095)	$ (62,067)	$ 19,914	$ (67,270)	$ (86,313)	$ (107,100)	$ (42,153)	$ (193,413)	$ (129,248)	$ (260,683)

Quarterly Financial Informati_5

Quarterly Financial Information (Unaudited) - Statements of Stockholders' Equity (Details) - USD ($) $ in Thousands	3 Months Ended						6 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2023	Jun. 30, 2023	Mar. 31, 2023	Sep. 30, 2022	Jun. 30, 2022	Mar. 31, 2022	Jun. 30, 2023	Jun. 30, 2022	Sep. 30, 2023	Sep. 30, 2022	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Common stock, shares outstanding (in shares)	107,022,000	106,454,000	106,370,000	82,880,000	73,551,000	71,438,000	106,454,000	73,551,000	107,022,000	82,880,000	192,772,000	82,923,000
Stockholders' equity											$ 194,537	$ 134,333	$ 276,129
Vesting of restricted stock units											$ (196)	0
Exercise of stock options (in shares)											3,000
Exercise of stock options											$ 92	16
Purchase of common stock under ESPP											429	239
Issuance of common stock											248,367	54,067
Issuance of unrestricted stock awards to settle accrued employee compensation												1
Stock-based compensation											21,151	35,382
Other comprehensive income											2,274	(1,159)
Net loss											$ (211,913)	$ (230,342)
Common shares
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Common stock, shares outstanding (in shares)											192,772,000	82,923,000	71,115,000
Stockholders' equity											$ 1,905	$ 830	$ 711
Vesting of restricted stock units (in shares)											1,092,000	979,000
Vesting of restricted stock units											$ 10	$ 10
Exercise of stock options (in shares)											24,000	7,000
Purchase of common stock under ESPP (in shares)											135,000	68,000
Purchase of common stock under ESPP											$ 2	$ 1
Issuance of common stock (in shares)											106,333,000	10,742,000
Issuance of common stock											$ 1,063	$ 107
Issuance of unrestricted stock awards to settle accrued employee compensation (in shares)												12,000
Issuance of unrestricted stock awards to settle accrued employee compensation												$ 1
Additional paid-in capital
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stockholders' equity											4,454,756	4,185,988	4,096,402
Vesting of restricted stock units											(206)	(10)
Exercise of stock options											92	16
Purchase of common stock under ESPP											427	238
Issuance of common stock											247,304	53,960
Stock-based compensation											21,151	35,382
Accumulated other comprehensive loss
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stockholders' equity											(1,796)	(4,070)	(2,911)
Other comprehensive income											2,274	(1,159)
Accumulated Deficit
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stockholders' equity											(4,260,328)	(4,048,415)	(3,818,073)
Net loss											$ (211,913)	(230,342)
Previously Reported
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stockholders' equity	$ 222,536	$ 289,019	$ 354,740	$ 158,857	$ 180,116	$ 263,259	$ 289,019	$ 180,116	$ 222,536	$ 158,857		196,343	$ 374,277
Vesting of restricted stock units	0	0	(195)	0	0	0						0
Exercise of stock options	8	77	7		1	1						16
Purchase of common stock under ESPP			227	239								239
Issuance of common stock	(50)		130,291	46,024	8,043							54,067
Issuance of unrestricted stock awards to settle accrued employee compensation												1
Stock-based compensation	5,153	6,388	5,843	9,212	8,908	12,681						35,480
Other comprehensive income	137	722	984	(214)	43	(1,548)						(1,159)
Net loss	$ (71,731)	$ (72,908)	$ 21,240	$ (76,520)	$ (100,138)	$ (122,152)	$ (51,668)	$ (222,290)	$ (123,399)	$ (298,810)		$ (266,578)
Previously Reported | Common shares
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Common stock, shares outstanding (in shares)	107,022,000	106,454,000	106,370,000	82,880,000	73,551,000	71,438,000	106,454,000	73,551,000	107,022,000	82,880,000		82,923,000	71,115,000
Stockholders' equity	$ 1,071	$ 1,065	$ 1,064	$ 829	$ 735	$ 714	$ 1,065	$ 735	$ 1,071	$ 829		$ 830	$ 711
Vesting of restricted stock units (in shares)	566,000	65,000	382,000	572,000	60,000	310,000						979,000
Vesting of restricted stock units	$ 6	$ 1	$ 3	$ 6	$ 1	$ 3						$ 10
Exercise of stock options (in shares)	2,000	19,000	3,000		1,000	1,000						7,000
Purchase of common stock under ESPP (in shares)			62,000	67,000								68,000
Purchase of common stock under ESPP			$ 1	$ 1								$ 1
Issuance of common stock (in shares)			23,000,000	8,690,000	2,052,000							10,742,000
Issuance of common stock			$ 230	$ 87	$ 20							$ 107
Issuance of unrestricted stock awards to settle accrued employee compensation (in shares)						12,000						12,000
Issuance of unrestricted stock awards to settle accrued employee compensation												$ 1
Previously Reported | Additional paid-in capital
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stockholders' equity	$ 4,333,594	$ 4,328,489	4,322,025	4,181,393	4,126,012	$ 4,109,081	4,328,489	4,126,012	4,333,594	4,181,393		4,186,086	4,096,402
Vesting of restricted stock units	(6)	(1)	(198)	(6)	(1)	(3)						(10)
Exercise of stock options	8	77	7		1	1						16
Purchase of common stock under ESPP			226	238								238
Issuance of common stock	(50)		130,061	45,937	8,023							53,960
Stock-based compensation	5,153	6,388	5,843	9,212	8,908	12,681						35,480
Previously Reported | Accumulated other comprehensive loss
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stockholders' equity	(2,227)	(2,364)	(3,086)	(4,630)	(4,416)	(4,459)	(2,364)	(4,416)	(2,227)	(4,630)		(4,070)	(2,911)
Other comprehensive income	137	722	984	(214)	43	(1,548)						(1,159)
Previously Reported | Accumulated Deficit
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stockholders' equity	(4,109,902)	(4,038,171)	(3,965,263)	(4,018,735)	(3,942,215)	(3,842,077)	(4,038,171)	(3,942,215)	(4,109,902)	(4,018,735)		(3,986,503)	(3,719,925)
Net loss	(71,731)	(72,908)	21,240	(76,520)	(100,138)	(122,152)						(266,578)
Revision of Prior Period, Error Correction, Adjustment | Adjustments to Leases
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stockholders' equity	(69,708)	(52,569)	(62,051)	(62,961)	(67,215)	(80,474)	(52,569)	(67,215)	(69,708)	(62,961)		(59,700)	$ (95,634)
Net loss	$ (17,139)	$ 9,482	$ (2,351)	$ 4,254	$ 13,259	$ 15,160	$ 7,131	$ 28,419	$ (10,008)	$ 32,673		$ 35,934
Revision of Prior Period, Error Correction, Adjustment | Adjustments to Leases | Common shares
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Common stock, shares outstanding (in shares)	0	0	0	0	0	0	0	0	0	0		0	0
Stockholders' equity	$ 0	$ 0	$ 0	$ 0	$ 0	$ 0	$ 0	$ 0	$ 0	$ 0		$ 0	$ 0
Revision of Prior Period, Error Correction, Adjustment | Adjustments to Leases | Additional paid-in capital
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stockholders' equity	0	0	0	0	0	0	0	0	0	0		0	0
Revision of Prior Period, Error Correction, Adjustment | Adjustments to Leases | Accumulated other comprehensive loss
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stockholders' equity	0	0	0	0	0	0	0	0	0	0		0	0
Revision of Prior Period, Error Correction, Adjustment | Adjustments to Leases | Accumulated Deficit
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stockholders' equity	(69,708)	(52,569)	(62,051)	(62,961)	(67,215)	(80,474)	(52,569)	(67,215)	(69,708)	(62,961)		(59,700)	(95,634)
Net loss	(17,139)	9,482	(2,351)	4,254	13,259	15,160						35,934
Revision of Prior Period, Error Correction, Adjustment | Other Adjustments
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stockholders' equity	6	(1,632)	(2,269)	2,616	(2,405)	(2,458)	(1,632)	(2,405)	6	2,616		(2,310)	$ (2,514)
Stock-based compensation				(189)	(470)	(1,384)						(98)
Net loss	$ 1,638	$ 637	$ 41	$ 5,210	$ 523	$ 1,440	$ 678	$ 1,963	$ 2,316	$ 7,173		$ 302
Revision of Prior Period, Error Correction, Adjustment | Other Adjustments | Common shares
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Common stock, shares outstanding (in shares)	0	0	0	0	0	0	0	0	0	0		0	0
Stockholders' equity	$ 0	$ 0	$ 0	$ 0	$ 0	$ 0	$ 0	$ 0	$ 0	$ 0		$ 0	$ 0
Revision of Prior Period, Error Correction, Adjustment | Other Adjustments | Additional paid-in capital
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stockholders' equity	(98)	(98)	(98)	(2,043)	(1,854)	(1,384)	(98)	(1,854)	(98)	(2,043)		(98)	0
Stock-based compensation				(189)	(470)	(1,384)						(98)
Revision of Prior Period, Error Correction, Adjustment | Other Adjustments | Accumulated other comprehensive loss
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stockholders' equity	0	0	0	0	0	0	0	0	0	0		0	0
Revision of Prior Period, Error Correction, Adjustment | Other Adjustments | Accumulated Deficit
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stockholders' equity	104	(1,534)	(2,171)	4,659	(551)	(1,074)	(1,534)	(551)	104	4,659		(2,212)	(2,514)
Net loss	1,638	637	41	5,210	523	1,440						302
As Restated
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stockholders' equity	152,834	234,818	290,420	98,512	110,496	180,327	234,818	110,496	152,834	98,512		$ 134,333	$ 276,129
Vesting of restricted stock units	0	0	(195)	0	0	0
Exercise of stock options	8	77	7		1	1
Purchase of common stock under ESPP			227	239
Issuance of common stock	(50)		130,291	46,024	8,043
Issuance of unrestricted stock awards to settle accrued employee compensation						0
Stock-based compensation	5,153	6,388	5,843	9,023	8,438	11,297
Other comprehensive income	137	722	984	(214)	43	(1,548)
Net loss	$ (87,232)	$ (62,789)	$ 18,930	$ (67,056)	$ (86,356)	$ (105,552)	$ (43,859)	$ (191,908)	$ (131,091)	$ (258,964)
As Restated | Common shares
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Common stock, shares outstanding (in shares)	107,022,000	106,454,000	106,370,000	82,880,000	73,551,000	71,438,000	106,454,000	73,551,000	107,022,000	82,880,000		82,923,000	71,115,000
Stockholders' equity	$ 1,071	$ 1,065	$ 1,064	$ 829	$ 735	$ 714	$ 1,065	$ 735	$ 1,071	$ 829		$ 830	$ 711
Vesting of restricted stock units (in shares)	566,000	65,000	382,000	572,000	60,000	310,000
Vesting of restricted stock units	$ 6	$ 1	$ 3	$ 6	$ 1	$ 3
Exercise of stock options (in shares)	2,000	19,000	3,000		1,000	1,000
Purchase of common stock under ESPP (in shares)			62,000	67,000
Purchase of common stock under ESPP			$ 1	$ 1
Issuance of common stock (in shares)			23,000,000	8,690,000	2,052,000
Issuance of common stock			$ 230	$ 87	$ 20
Issuance of unrestricted stock awards to settle accrued employee compensation (in shares)						12,000
As Restated | Additional paid-in capital
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stockholders' equity	$ 4,333,496	$ 4,328,391	4,321,927	4,179,350	4,124,158	$ 4,107,697	4,328,391	4,124,158	4,333,496	4,179,350		4,185,988	4,096,402
Vesting of restricted stock units	(6)	(1)	(198)	(6)	(1)	(3)
Exercise of stock options	8	77	7		1	1
Purchase of common stock under ESPP			226	238
Issuance of common stock	(50)		130,061	45,937	8,023
Stock-based compensation	5,153	6,388	5,843	9,023	8,438	11,297
As Restated | Accumulated other comprehensive loss
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stockholders' equity	(2,227)	(2,364)	(3,086)	(4,630)	(4,416)	(4,459)	(2,364)	(4,416)	(2,227)	(4,630)		(4,070)	(2,911)
Other comprehensive income	137	722	984	(214)	43	(1,548)
As Restated | Accumulated Deficit
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stockholders' equity	(4,179,506)	(4,092,274)	(4,029,485)	(4,077,037)	(4,009,981)	(3,923,625)	$ (4,092,274)	$ (4,009,981)	$ (4,179,506)	$ (4,077,037)		$ (4,048,415)	$ (3,818,073)
Net loss	$ (87,232)	$ (62,789)	$ 18,930	$ (67,056)	$ (86,356)	$ (105,552)

Quarterly Financial Informati_6

Quarterly Financial Information (Unaudited) - Statements of Cash Flows (Details) - USD ($) $ in Thousands	3 Months Ended						6 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2023	Jun. 30, 2023	Mar. 31, 2023	Sep. 30, 2022	Jun. 30, 2022	Mar. 31, 2022	Jun. 30, 2023	Jun. 30, 2022	Sep. 30, 2023	Sep. 30, 2022	Dec. 31, 2023	Dec. 31, 2022
Cash flows from operating activities:
Net loss											$ (211,913)	$ (230,342)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization											28,525	8,344
Stock-based compensation expense											19,429	35,090
Noncash research and development expense (finance lease)											21,198	11,180
Noncash operating lease expense											29,772	23,562
Gain from sale of priority review voucher											(92,930)	(102,000)
Excess inventory reserve											15,363	7,519
Unrealized loss (gain) on equity securities											0	3,135
Other non-cash items											24	4,138
Gain on foreign currency exchange rates											167	(1,801)
Changes in operating assets and liabilities:
Prepaid expenses and other assets											(3,894)	(4,820)
Inventory											(36,560)	(7,227)
Operating lease right-of-use assets												0
Accounts payable											2,841	(7,709)
Accrued expenses and other liabilities											13,353	(45,974)
Accrued interest payable under finance lease											3,426	4,758
Operating lease liabilities											(28,887)	(14,072)
Net cash used in operating activities											(235,046)	(316,219)
Cash flows from investing activities:
Purchase of property, plant and equipment											(4,189)	(8,208)
Purchases of marketable securities											(43,297)	0
Proceeds from maturities of marketable securities											108,521	131,445
Proceeds from sales of marketable securities											5,853	30,216
Purchase of intangible assets											(4,868)	(5,000)
Proceeds from sale of priority review voucher											92,930	102,000
Net cash provided by investing activities											154,950	250,453
Cash flows from financing activities:
Proceeds from exercise of stock options and ESPP contributions												16
Proceeds from issuance of common stock											248,198	54,237
Principal payments on finance leases											(54,367)	(36,734)
Proceeds from the transfer of invoices											2,520	0
Net cash provided by financing activities											196,248	17,519
Increase (decrease) in cash, cash equivalents and restricted cash											116,152	(48,247)
Cash, cash equivalents and restricted cash at beginning of year			$ 158,445			$ 206,692	$ 158,445	$ 206,692	$ 158,445	$ 206,692	158,445	206,692
Cash, cash equivalents and restricted cash at end of year											274,597	158,445
Reconciliation of cash, cash equivalents and restricted cash:
Cash and cash equivalents											221,755	113,006
Restricted cash included in receivables and other current assets											9,202	1,502
Restricted cash included in restricted cash and other non-current assets											43,640	43,937
Total cash, cash equivalents and restricted cash											274,597	158,445
Supplemental cash flow disclosures:
Right-of-use assets obtained in exchange for operating lease liabilities												221,036
Right-of-use assets obtained in exchange for operating lease liabilities											(708)	221,036
Increase (Reduction) of right of use asset and associated operating lease liability due to lease reassessment												0
Purchases of property, plant and equipment included in accounts payable and accrued expenses											884	(3)
Offering expenses included in accounts payable and accrued expenses											964	170
Right-of-use assets obtained in exchange for finance lease liabilities											21,929	73,443
Cash paid (refunded) during the period for income taxes												253
Public Offering
Cash flows from financing activities:
Proceeds from issuance of common stock			130,645				130,122	8,043	130,072	54,365		54,237
Previously Reported
Cash flows from operating activities:
Net loss	$ (71,731)	$ (72,908)	21,240	$ (76,520)	$ (100,138)	(122,152)	(51,668)	(222,290)	(123,399)	(298,810)		(266,578)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization			1,082			1,014	2,052	2,358	3,124	3,745		5,001
Stock-based compensation expense			5,391			12,390	11,145	21,298	16,013	30,509		35,188
Noncash research and development expense (finance lease)			0			0	0	0	0	0		0
Noncash operating lease expense			0			0	0	0	0	0		0
Gain from sale of priority review voucher			(92,930)				(92,930)		(92,930)			(102,000)
Excess inventory reserve			228			7,519	3,939	7,519	5,333	7,519		7,519
Unrealized loss (gain) on equity securities						2,508		3,135		3,135		3,135
Other non-cash items (finance lease)						0			0
Other non-cash items			237			189	343	661	19	2,890		3,904
Gain on foreign currency exchange rates			0			0	0	0	0	0		0
Changes in operating assets and liabilities:
Accounts receivable									(23,000)
Prepaid expenses and other assets			(9,335)			(4,303)	(9,082)	(9,629)	(523)	(6,197)		3,260
Inventory			(3,586)			(8,756)	(16,496)		(24,931)			(7,227)
Operating lease right-of-use assets			11,829			6,517	24,102	17,636	40,101	29,650		42,706
Accounts payable			(6,443)			2,467	(14,767)	(1,175)	(5,787)	(7,552)		(920)
Accrued expenses and other liabilities			(9,065)			(16,561)	3,625	(28,565)	7,125	(39,046)		(51,228)
Accrued interest payable under finance lease			0			0	0	0	0	0		0
Operating lease liabilities			(8,001)			(6,128)	(19,488)	(10,602)	(30,506)	(22,523)		(25,713)
Deferred revenue			2,715				(138)		8,152
Net cash used in operating activities			(86,638)			(125,296)	(159,363)	(219,654)	(221,209)	(296,680)		(352,953)
Cash flows from investing activities:
Purchase of property, plant and equipment			(232)			(857)	(937)	(6,836)	(2,975)	(8,100)		(8,208)
Purchases of marketable securities			(19,610)				(34,418)		(43,297)
Proceeds from maturities of marketable securities			4,021			70,783	26,521	108,225	99,521	125,095		131,445
Proceeds from sales of marketable securities			5,853				5,853	30,213	5,853	30,216		30,216
Purchase of intangible assets			(868)				(868)		(868)	0		(5,000)
Proceeds from sale of priority review voucher			92,972				92,930		92,930			102,000
Net cash provided by investing activities			82,136			69,926	89,081	131,602	151,164	147,211		250,453
Cash flows from financing activities:
Proceeds from exercise of stock options and ESPP contributions			7			9	85		93	3		16
Principal payments on finance leases			0			0	0	0	0	0		0
Net cash provided by financing activities			130,456			9	130,011	8,043	129,969	54,368		54,253
Increase (decrease) in cash, cash equivalents and restricted cash			125,954			(55,361)	59,729	(80,009)	59,924	(95,101)		(48,247)
Cash, cash equivalents and restricted cash at beginning of year	218,174	284,399	158,445	126,684	151,332	206,692	158,445	206,692	158,445	206,692	158,445	206,692
Cash, cash equivalents and restricted cash at end of year	218,369	218,174	284,399	111,592	126,684	151,332	218,174	126,684	218,369	111,592		158,445
Reconciliation of cash, cash equivalents and restricted cash:
Cash and cash equivalents	165,347	172,872	239,045	66,478	81,499	106,260	172,872	81,499	165,347	66,478		113,006
Restricted cash included in receivables and other current assets	8,885	1,364	1,417	1,565	1,635	1,822	1,364	1,635	8,885	1,565		1,502
Restricted cash included in restricted cash and other non-current assets	44,137	43,938	43,937	43,549	43,550	43,250	43,938	43,550	44,137	43,549		43,937
Total cash, cash equivalents and restricted cash	218,369	218,174	284,399	111,592	126,684	151,332	218,174	126,684	218,369	111,592		158,445
Supplemental cash flow disclosures:
Right-of-use assets obtained in exchange for operating lease liabilities						26,882	44,968	218,836		229,636		236,003
Right-of-use assets obtained in exchange for operating lease liabilities									44,819
Increase (Reduction) of right of use asset and associated operating lease liability due to lease reassessment							(14)		8,003	(2,833)		(2,833)
Purchases of property, plant and equipment included in accounts payable and accrued expenses			189			2,134	2,290	842	941	176		(3)
Offering expenses included in accounts payable and accrued expenses			523						248	298		170
Priority review voucher expenses accrued or in AP			43
Right-of-use assets obtained in exchange for finance lease liabilities			0				0		0	0		0
Cash paid (refunded) during the period for income taxes			2				7		5			253
Previously Reported | Private Placement
Cash flows from financing activities:
Proceeds from issuance of common stock			(196)				(196)		(196)
Previously Reported In Quarterly Period
Cash flows from financing activities:
Cash, cash equivalents and restricted cash at beginning of year						206,693		206,693		206,693		206,693
Reconciliation of cash, cash equivalents and restricted cash:
Total cash, cash equivalents and restricted cash
Revision of Prior Period, Error Correction, Adjustment | Adjustments to Leases
Cash flows from operating activities:
Net loss	(17,139)	9,482	(2,351)	4,254	13,259	15,160	7,131	28,419	(10,008)	32,673		35,934
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization			5,131			89	10,274	179	16,648	268		3,547
Stock-based compensation expense			0			0	0	0	0	0		0
Noncash research and development expense (finance lease)			1,441			4,050	434	4,050	22,223	11,866		11,180
Noncash operating lease expense			7,423			3,035	14,966	9,738	23,965	16,517		23,562
Gain from sale of priority review voucher			0				0		0			0
Excess inventory reserve			0			0	0	0	1,554	0		0
Unrealized loss (gain) on equity securities						0		0		0		0
Other non-cash items (finance lease)						0			0
Other non-cash items			0			0	0	234	0	234		234
Gain on foreign currency exchange rates			(108)			(530)	(281)	(1,874)	(1,062)	(3,301)		(1,801)
Changes in operating assets and liabilities:
Accounts receivable									0
Prepaid expenses and other assets			2,846			(2,591)	2,642	(6,389)	2,640	(6,508)		(8,080)
Inventory			610			0	1,838		1,651			0
Operating lease right-of-use assets			(11,829)			(6,517)	(24,102)	(17,636)	(40,101)	(29,650)		(42,706)
Accounts payable			7,703			(1,501)	9,144	590	7,183	537		(6,789)
Accrued expenses and other liabilities			1,859			(12,618)	(573)	(9,308)	583	(10,388)		5,254
Accrued interest payable under finance lease			915			1,014	819	1,924	3,203	3,464		4,758
Operating lease liabilities			1,640			5,981	6,212	8,656	11,820	11,580		11,641
Deferred revenue			0				0		0
Net cash used in operating activities			15,280			5,572	28,504	18,583	40,299	27,292		36,734
Cash flows from investing activities:
Purchase of property, plant and equipment			0			0	0	0	0	0		0
Purchases of marketable securities			0				0		0
Proceeds from maturities of marketable securities			0			0	0	0	0	0		0
Proceeds from sales of marketable securities			0				0	0	0	0		0
Purchase of intangible assets			0				0		0	0		0
Proceeds from sale of priority review voucher			0				0		0			0
Net cash provided by investing activities			0			0	0	0	0	0		0
Cash flows from financing activities:
Proceeds from exercise of stock options and ESPP contributions			0			0	0		0	0		0
Proceeds from issuance of common stock							0		0	0
Principal payments on finance leases			(15,280)			(5,572)	(28,504)	(18,583)	(40,299)	(27,292)		(36,734)
Net cash provided by financing activities			(15,280)			(5,572)	(28,504)	(18,583)	(40,299)	(27,292)		(36,734)
Increase (decrease) in cash, cash equivalents and restricted cash			0			0	0	0	0	0		0
Cash, cash equivalents and restricted cash at beginning of year	0	0	0	0	0	0	0	0	0	0	0	0
Cash, cash equivalents and restricted cash at end of year	0	0	0	0	0	0	0	0	0	0		0
Reconciliation of cash, cash equivalents and restricted cash:
Cash and cash equivalents	0	0	0	0	0	0	0	0	0	0		0
Restricted cash included in receivables and other current assets	0	0	0	0	0	0	0	0	0	0		0
Restricted cash included in restricted cash and other non-current assets	0	0	0	0	0	0	0	0	0	0		0
Total cash, cash equivalents and restricted cash	0	0	0	0	0	0	0	0	0	0		0
Supplemental cash flow disclosures:
Right-of-use assets obtained in exchange for operating lease liabilities						(1,829)	(44,968)	(3,796)		(14,596)		(14,967)
Right-of-use assets obtained in exchange for operating lease liabilities									(45,527)
Increase (Reduction) of right of use asset and associated operating lease liability due to lease reassessment							14		(8,003)	2,833		2,833
Purchases of property, plant and equipment included in accounts payable and accrued expenses			0			0	0	0	0	0		0
Offering expenses included in accounts payable and accrued expenses			0						0	0		0
Priority review voucher expenses accrued or in AP			0
Right-of-use assets obtained in exchange for finance lease liabilities			(214)				3,436		21,508	10,800		73,443
Cash paid (refunded) during the period for income taxes			0				0		0			0
Revision of Prior Period, Error Correction, Adjustment | Adjustments to Leases | Private Placement
Cash flows from financing activities:
Proceeds from issuance of common stock			0				0		0
Revision of Prior Period, Error Correction, Adjustment | Adjustments to Leases | Public Offering
Cash flows from financing activities:
Proceeds from issuance of common stock			0					0				0
Revision of Prior Period, Error Correction, Adjustment | Other Adjustments
Cash flows from operating activities:
Net loss	1,638	637	41	5,210	523	1,440	678	1,963	2,316	7,173		302
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization			(41)			(56)	(76)	(108)	(112)	(129)		(204)
Stock-based compensation expense			0			(1,384)	0	(1,855)	0	(2,044)		(98)
Noncash research and development expense (finance lease)			0			0	0	0	0	0		0
Noncash operating lease expense			0			0	0	0	0	0		0
Gain from sale of priority review voucher			0				0		0			0
Excess inventory reserve			2,355			0	2,339	0	2,315	0		0
Unrealized loss (gain) on equity securities						0		0		0		0
Other non-cash items (finance lease)						0			0
Other non-cash items			0			0	0	0	81	0		0
Gain on foreign currency exchange rates			0			0	0	0	0	0		0
Changes in operating assets and liabilities:
Accounts receivable									8,400
Prepaid expenses and other assets			2,800			0	0	0	0	0		0
Inventory			(2,355)			0	(2,941)		(2,917)			0
Operating lease right-of-use assets			0			0	0	0	0	0		0
Accounts payable			0			0	0	0	316	0		0
Accrued expenses and other liabilities			0			0	0	0	(1,999)	0		0
Accrued interest payable under finance lease			0			0	0	0	0	0		0
Operating lease liabilities			0			0	0	0	0	0		0
Deferred revenue			(2,800)				0		(8,400)
Net cash used in operating activities			0			0	0	0	0	5,000		0
Cash flows from investing activities:
Purchase of property, plant and equipment			0			0	0	0	0	0		0
Purchases of marketable securities			0				0		0
Proceeds from maturities of marketable securities			0			0	0	0	0	0		0
Proceeds from sales of marketable securities			0				0	0	0	0		0
Purchase of intangible assets			0				0		0	(5,000)		0
Proceeds from sale of priority review voucher			0				0		0			0
Net cash provided by investing activities			0			0	0	0	0	(5,000)		0
Cash flows from financing activities:
Proceeds from exercise of stock options and ESPP contributions			0			0	0		0	0		0
Proceeds from issuance of common stock							0		0	0
Principal payments on finance leases			0			0	0	0	0	0		0
Net cash provided by financing activities			0			0	0	0	0	0		0
Increase (decrease) in cash, cash equivalents and restricted cash			0			0	0	0	0	0		0
Cash, cash equivalents and restricted cash at beginning of year	0	0	0	0	0	0	0	0	0	0	0	0
Cash, cash equivalents and restricted cash at end of year	0	0	0	0	0	0	0	0	0	0		0
Reconciliation of cash, cash equivalents and restricted cash:
Cash and cash equivalents	0	0	0	0	0	0	0	0	0	0		0
Restricted cash included in receivables and other current assets	0	0	0	0	0	0	0	0	0	0		0
Restricted cash included in restricted cash and other non-current assets	0	0	0	0	0	0	0	0	0	0		0
Total cash, cash equivalents and restricted cash	0	0	0	0	0	0	0	0	0	0		0
Supplemental cash flow disclosures:
Right-of-use assets obtained in exchange for operating lease liabilities						0	0	0		0		0
Right-of-use assets obtained in exchange for operating lease liabilities									0
Increase (Reduction) of right of use asset and associated operating lease liability due to lease reassessment							0		0	0		0
Purchases of property, plant and equipment included in accounts payable and accrued expenses			0			0	0	0	0	0		0
Offering expenses included in accounts payable and accrued expenses			0						0	0		0
Priority review voucher expenses accrued or in AP			0
Right-of-use assets obtained in exchange for finance lease liabilities			0				0		0	0		0
Cash paid (refunded) during the period for income taxes			0				0		0			0
Revision of Prior Period, Error Correction, Adjustment | Other Adjustments | Private Placement
Cash flows from financing activities:
Proceeds from issuance of common stock			0				0		0
Revision of Prior Period, Error Correction, Adjustment | Other Adjustments | Public Offering
Cash flows from financing activities:
Proceeds from issuance of common stock			0					0				0
As Restated
Cash flows from operating activities:
Net loss	(87,232)	(62,789)	18,930	(67,056)	(86,356)	(105,552)	(43,859)	(191,908)	(131,091)	(258,964)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization			6,172			1,047	12,250	2,429	19,660	3,884
Stock-based compensation expense			5,391			11,006	11,145	19,443	16,013	28,465
Noncash research and development expense (finance lease)			1,441			4,050	434	4,050	22,223	11,866
Noncash operating lease expense			7,423			3,035	14,966	9,738	23,965	16,517
Gain from sale of priority review voucher			(92,930)				(92,930)		(92,930)
Excess inventory reserve			2,583			7,519	6,278	7,519	9,202	7,519
Unrealized loss (gain) on equity securities						2,508		3,135		3,135
Other non-cash items (finance lease)						0			0
Other non-cash items			237			189	343	895	100	3,124
Gain on foreign currency exchange rates			(108)			(530)	(281)	(1,874)	(1,062)	(3,301)
Changes in operating assets and liabilities:
Accounts receivable									(14,600)
Prepaid expenses and other assets			(3,689)			(6,894)	(6,440)	(16,018)	2,117	(12,705)
Inventory			(5,331)			(8,756)	(17,599)		(26,197)
Operating lease right-of-use assets			0			0	0	0	0	0
Accounts payable			1,260			966	(5,623)	(585)	1,712	(7,015)
Accrued expenses and other liabilities			(7,206)			(29,179)	3,052	(37,873)	5,709	(49,434)
Accrued interest payable under finance lease			915			1,014	819	1,924	3,203	3,464
Operating lease liabilities			(6,361)			(147)	(13,276)	(1,946)	(18,686)	(10,943)
Deferred revenue			(85)				(138)		(248)
Net cash used in operating activities			(71,358)			(119,724)	(130,859)	(201,071)	(180,910)	(264,388)
Cash flows from investing activities:
Purchase of property, plant and equipment			(232)			(857)	(937)	(6,836)	(2,975)	(8,100)
Purchases of marketable securities			(19,610)				(34,418)		(43,297)
Proceeds from maturities of marketable securities			4,021			70,783	26,521	108,225	99,521	125,095
Proceeds from sales of marketable securities			5,853				5,853	30,213	5,853	30,216
Purchase of intangible assets			(868)				(868)		(868)	(5,000)
Proceeds from sale of priority review voucher			92,972				92,930		92,930
Net cash provided by investing activities			82,136			69,926	89,081	131,602	151,164	142,211
Cash flows from financing activities:
Proceeds from exercise of stock options and ESPP contributions			7			9	85		93	3
Proceeds from issuance of common stock							130,122		130,072	54,365
Principal payments on finance leases			(15,280)			(5,572)	(28,504)	(18,583)	(40,299)	(27,292)
Net cash provided by financing activities			115,176			(5,563)	101,507	(10,540)	89,670	27,076
Increase (decrease) in cash, cash equivalents and restricted cash			125,954			(55,361)	59,729	(80,009)	59,924	(95,101)
Cash, cash equivalents and restricted cash at beginning of year	218,174	284,399	158,445	126,684	151,332	206,693	158,445	206,693	158,445	206,693	$ 158,445	206,693
Cash, cash equivalents and restricted cash at end of year	218,369	218,174	284,399	111,592	126,684	151,332	218,174	126,684	218,369	111,592		158,445
Reconciliation of cash, cash equivalents and restricted cash:
Cash and cash equivalents	165,347	172,872	239,045	66,478	81,499	106,260	172,872	81,499	165,347	66,478
Restricted cash included in receivables and other current assets	8,885	1,364	1,417	1,565	1,635	1,822	1,364	1,635	8,885	1,565
Restricted cash included in restricted cash and other non-current assets	44,137	43,938	43,937	43,549	43,550	43,250	43,938	43,550	44,137	43,549
Total cash, cash equivalents and restricted cash	$ 218,369	$ 218,174	284,399	$ 111,592	$ 126,684	151,332	218,174	126,684	218,369	111,592		$ 158,445
Supplemental cash flow disclosures:
Right-of-use assets obtained in exchange for operating lease liabilities						25,053	0	215,040		215,040
Right-of-use assets obtained in exchange for operating lease liabilities									(708)
Increase (Reduction) of right of use asset and associated operating lease liability due to lease reassessment							0		0	0
Purchases of property, plant and equipment included in accounts payable and accrued expenses			189			$ 2,134	2,290	842	941	176
Offering expenses included in accounts payable and accrued expenses			523						248	298
Priority review voucher expenses accrued or in AP			43
Right-of-use assets obtained in exchange for finance lease liabilities			(214)				3,436		21,508	$ 10,800
Cash paid (refunded) during the period for income taxes			2				7		5
As Restated | Private Placement
Cash flows from financing activities:
Proceeds from issuance of common stock			(196)				$ (196)		$ (196)
As Restated | Public Offering
Cash flows from financing activities:
Proceeds from issuance of common stock			$ 130,645					$ 8,043

Subsequent events (Details)

Subsequent events (Details) - Subsequent Event $ / shares in Units, $ in Thousands	Aug. 13, 2024 USD ($) $ / shares	Mar. 15, 2024 USD ($) tranche
The Warrants
Subsequent Event [Line Items]
Value of warrants issued in relation to debt	$ 3,750
Weighted average price, period	10 days
Exercise price of warrants (in dollars per share) | $ / shares	$ 1.45
Secured Debt | Line of Credit
Subsequent Event [Line Items]
Annual financial statement delivery period		90 days
Quarterly financial statement delivery period		45 days
Minimum cash coverage as a percentage of outstanding principal	45%	40%
Secured Debt | Line of Credit | The Warrants
Subsequent Event [Line Items]
Warrants issued as a percentage of debt	0.05
Secured Debt | Term Loan Facility | Line of Credit
Subsequent Event [Line Items]
Debt term		5 years
Number of tranches | tranche		4
Number of additional tranches | tranche		2
Line of credit maximum borrowing capacity		$ 175,000
Proceeds from loans		75,000
Secured Debt | Term Loan Facility | Line of Credit | Debt Instrument Availability, Tranche Two
Subsequent Event [Line Items]
Debt amount		25,000
Secured Debt | Term Loan Facility | Line of Credit | Debt Instrument Availability, Tranche Three
Subsequent Event [Line Items]
Debt amount		25,000
Secured Debt | Term Loan Facility | Line of Credit | Debt Instrument Availability, Tranche Four
Subsequent Event [Line Items]
Debt amount		$ 50,000
Secured Debt | Term Loan Facility Tranche Two | Line of Credit
Subsequent Event [Line Items]
Line of credit maximum borrowing capacity	$ 25,000
Period immediately following achievement	30 days
Debt covenant, minimum gross cash proceeds	$ 75,000
Secured Debt | Term Loan Facility Tranche Three | Line of Credit
Subsequent Event [Line Items]
Line of credit maximum borrowing capacity	$ 25,000
Period immediately following achievement	30 days
Debt covenant, product delivery period	6 months
Secured Debt | Term Loan Facility Tranche Three | Line of Credit | Proceeds Received December 20, 2024
Subsequent Event [Line Items]
Debt covenant, minimum gross cash proceeds	$ 100,000
Secured Debt | Term Loan Facility Tranche Three | Line of Credit | Proceeds Received June 30, 2025
Subsequent Event [Line Items]
Debt covenant, minimum gross cash proceeds	$ 125,000