Autolus Therapeutics (AUTL) 10-Q 9 Nov 23 2023 Q3 Quarterly report Financial data

Cover

Cover - shares	9 Months Ended
	Sep. 30, 2023	Nov. 09, 2023
Cover [Abstract]
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Sep. 30, 2023
Document Transition Report	false
Entity File Number	001-38547
Entity Registrant Name	AUTOLUS THERAPEUTICS PLC
Entity Incorporation, State or Country Code	X0
Entity Address, Address Line One	The Mediaworks
Entity Address, Address Line Two	191 Wood Lane
Entity Address, City or Town	London
Entity Address, Postal Zip Code	W12 7FP
Entity Address, Country	GB
City Area Code	(44) 20
Local Phone Number	3829 6230
Title of 12(b) Security	American Depositary Shares, each representing one ordinary share, par value $0.000042 per share
Trading Symbol	AUTL
Security Exchange Name	NASDAQ
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	true
Entity Ex Transition Period	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		173,989,157
Entity Central Index Key	0001730463
Amendment Flag	false
Document Fiscal Year Focus	2023
Document Fiscal Period Focus	Q3
Current Fiscal Year End Date	--12-31

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets (Unaudited) - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022
Current assets:
Cash and cash equivalents	$ 256,415	$ 382,436
Restricted cash	434	325
Prepaid expenses and other current assets	51,533	43,010
Total current assets	308,382	425,771
Non-current assets:
Property and equipment, net	34,637	35,209
Prepaid expenses and other non-current assets	136	2,176
Operating lease right-of-use assets, net	59,403	23,210
Long-term deposits	943	1,832
Deferred tax asset	2,597	2,076
Total assets	406,098	490,274
Current liabilities:
Accounts payable	661	531
Accrued expenses and other liabilities	31,388	40,797
Operating lease liabilities, current	5,491	5,038
Total current liabilities	37,540	46,366
Non-current liabilities:
Operating lease liabilities, non-current	46,967	19,218
Liability related to future royalties and sales milestones, net	140,778	125,900
Other long-term payables	295	116
Total liabilities	225,580	191,600
Commitments and contingencies
Shareholders' equity:
Additional paid-in capital	1,015,577	1,007,625
Accumulated other comprehensive loss	(33,794)	(38,898)
Accumulated deficit	(801,391)	(670,179)
Total shareholders' equity	180,518	298,674
Total liabilities and shareholders' equity	406,098	490,274
Ordinary shares
Shareholders' equity:
Share value	8	8
Deferred shares
Shareholders' equity:
Share value	0	0
Deferred B Shares
Shareholders' equity:
Share value	118	118
Deferred C Shares
Shareholders' equity:
Share value	$ 0	$ 0

Condensed Consolidated Balanc_2

Condensed Consolidated Balance Sheets (Unaudited) (Parentheticals)	Sep. 30, 2023 $ / shares shares	Sep. 30, 2023 £ / shares shares	Dec. 31, 2022 $ / shares shares	Dec. 31, 2022 £ / shares shares
Ordinary shares
Shareholders' equity:
Stock par value (usd/gbp per share) | $ / shares	$ 0.000042		$ 0.000042
Shares authorized (in shares)	290,909,783	290,909,783	290,909,783	290,909,783
Shares issued (in shares)	173,936,794	173,936,794	173,074,510	173,074,510
Shares outstanding (in shares)	173,936,794	173,936,794	173,074,510	173,074,510
Deferred shares
Shareholders' equity:
Stock par value (usd/gbp per share) | £ / shares		£ 0.00001		£ 0.00001
Shares authorized (in shares)	34,425	34,425	34,425	34,425
Shares issued (in shares)	34,425	34,425	34,425	34,425
Shares outstanding (in shares)	34,425	34,425	34,425	34,425
Deferred B Shares
Shareholders' equity:
Stock par value (usd/gbp per share) | £ / shares		£ 0.00099		£ 0.00099
Shares authorized (in shares)	88,893,548	88,893,548	88,893,548	88,893,548
Shares issued (in shares)	88,893,548	88,893,548	88,893,548	88,893,548
Shares outstanding (in shares)	88,893,548	88,893,548	88,893,548	88,893,548
Deferred C Shares
Shareholders' equity:
Stock par value (usd/gbp per share) | £ / shares		£ 0.000008		£ 0.000008
Shares authorized (in shares)	1	1	1	1
Shares issued (in shares)	1	1	1	1
Shares outstanding (in shares)	1	1	1	1

Condensed Consolidated Statemen

Condensed Consolidated Statements of Operations and Comprehensive Loss (Unaudited) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Operating expenses:
Research and development	$ (37,237)	$ (37,632)	$ (105,323)	$ (109,806)
General and administrative	(10,611)	(8,231)	(31,017)	(24,487)
Loss on disposal of property and equipment	0	0	(3,791)	0
Impairment of operating lease right-of-use assets and related property and equipment	(382)	0	(382)	0
Total operating expenses, net	(47,824)	(43,494)	(138,815)	(131,758)
Other income (expense):
Other expenses, net	(1,597)	(3,740)	(333)	(4,214)
Interest income	3,646	165	10,495	282
Interest expense	(5,014)	(1,850)	(14,939)	(5,448)
Total other expense, net	(2,965)	(5,425)	(4,777)	(9,380)
Net loss before income tax	(50,789)	(48,919)	(143,592)	(141,138)
Income tax benefit	4,940	6,152	12,380	19,250
Net loss attributable to ordinary shareholders	(45,849)	(42,767)	(131,212)	(121,888)
Other comprehensive (loss) income:
Foreign currency exchange translation adjustment	(5,837)	(14,054)	5,104	(38,994)
Total comprehensive loss	$ (51,686)	$ (56,821)	$ (126,108)	$ (160,882)
Basic net loss per ordinary share (in usd per share)	$ (0.26)	$ (0.47)	$ (0.75)	$ (1.34)
Diluted net loss per ordinary share (in usd per share)	$ (0.26)	$ (0.47)	$ (0.75)	$ (1.34)
Weighted-average basic ordinary shares (in shares)	173,984,101	91,240,801	173,890,666	91,028,562
Weighted-average diluted ordinary shares (in shares)	173,984,101	91,240,801	173,890,666	91,028,562
Grant income
Revenues	$ 0	$ 0	$ 0	$ 166
License revenue
Revenues	$ 406	$ 2,369	$ 1,698	$ 2,369

Condensed Consolidated Statem_2

Condensed Consolidated Statements of Shareholders’ Equity (Unaudited) - USD ($) $ in Thousands	Total	Ordinary Shares	Deferred Shares	Deferred B Shares	Deferred C Shares	Common shares Ordinary Shares	Common shares Deferred Shares	Common shares Deferred B Shares	Common shares Deferred C Shares	Additional Paid in Capital	Accumulated other comprehensive loss	Accumulated deficit
Beginning balance (in shares) at Dec. 31, 2021						90,907,830	34,425	88,893,548	1
Beginning balance at Dec. 31, 2021	$ 313,320					$ 4	$ 0	$ 118	$ 0	$ 843,108	$ (8,570)	$ (521,340)
Stockholders' Equity
Share-based compensation expense	8,599									8,599
Vesting of restricted stock (in shares)						76,804
Vesting of restricted stock	0
Exercise of share options (in shares)						147,722
Exercise of share options	117									117
Unrealized loss on foreign currency translation	(38,994)										(38,994)
Net loss	(121,888)											(121,888)
Ending balance (in shares) at Sep. 30, 2022						91,132,356	34,425	88,893,548	1
Ending balance at Sep. 30, 2022	161,154					$ 4	$ 0	$ 118	$ 0	851,824	(47,564)	(643,228)
Beginning balance (in shares) at Jun. 30, 2022						90,909,783	34,425	88,893,548	1
Beginning balance at Jun. 30, 2022	214,521					$ 4	$ 0	$ 118	$ 0	848,370	(33,510)	(600,461)
Stockholders' Equity
Share-based compensation expense	3,337									3,337
Vesting of restricted stock (in shares)						76,804
Vesting of restricted stock	0
Exercise of share options (in shares)						145,769
Exercise of share options	117									117
Unrealized loss on foreign currency translation	(14,054)										(14,054)
Net loss	(42,767)											(42,767)
Ending balance (in shares) at Sep. 30, 2022						91,132,356	34,425	88,893,548	1
Ending balance at Sep. 30, 2022	161,154					$ 4	$ 0	$ 118	$ 0	851,824	(47,564)	(643,228)
Beginning balance (in shares) at Dec. 31, 2022		173,074,510	34,425	88,893,548	1	173,074,510	34,425	88,893,548	1
Beginning balance at Dec. 31, 2022	298,674					$ 8	$ 0	$ 118	$ 0	1,007,625	(38,898)	(670,179)
Stockholders' Equity
Share-based compensation expense	7,948									7,948
Vesting of restricted stock (in shares)						860,213
Vesting of restricted stock	0
Exercise of share options (in shares)						2,071
Exercise of share options	4									4
Unrealized loss on foreign currency translation	5,104										5,104
Net loss	(131,212)											(131,212)
Ending balance (in shares) at Sep. 30, 2023		173,936,794	34,425	88,893,548	1	173,936,794	34,425	88,893,548	1
Ending balance at Sep. 30, 2023	180,518					$ 8	$ 0	$ 118	$ 0	1,015,577	(33,794)	(801,391)
Beginning balance (in shares) at Jun. 30, 2023						173,680,872	34,425	88,893,548	1
Beginning balance at Jun. 30, 2023	229,336					$ 8	$ 0	$ 118	$ 0	1,012,709	(27,957)	(755,542)
Stockholders' Equity
Share-based compensation expense	2,864									2,864
Vesting of restricted stock (in shares)						253,851
Vesting of restricted stock	0
Exercise of share options (in shares)						2,071
Exercise of share options	4									4
Unrealized loss on foreign currency translation	(5,837)										(5,837)
Net loss	(45,849)											(45,849)
Ending balance (in shares) at Sep. 30, 2023		173,936,794	34,425	88,893,548	1	173,936,794	34,425	88,893,548	1
Ending balance at Sep. 30, 2023	$ 180,518					$ 8	$ 0	$ 118	$ 0	$ 1,015,577	$ (33,794)	$ (801,391)

Condensed Consolidated Statem_3

Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022	Dec. 31, 2022
Cash flows from operating activities:
Net loss	$ (45,849)	$ (42,767)	$ (131,212)	$ (121,888)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization			4,790	5,773
Share-based compensation net of amounts capitalized			7,929	8,599
Interest expense accrued on liability related to future royalties and sales milestones, net	5,000	1,800	14,878	5,427
Foreign exchange differences			(366)	10,537
Loss on termination of operating lease			95	0
Loss on disposal of property and equipment			3,812	0
Impairment of operating lease right-of-use assets and related property and equipment	382	0	382	0
Deferred income tax			(520)	(587)
Changes in operating assets and liabilities:
Prepaid expenses and other current assets			(7,655)	(20,809)
Non-current prepaid expenses and other non-current assets			1,932	301
Long-term deposits			937	(5)
Accounts payable			69	(87)
Accrued expenses and other liabilities			(6,823)	15,469
Current and non-current operating lease liabilities, net of operating lease right of use assets			(9,002)	(472)
Net cash used in operating activities			(120,754)	(97,742)
Cash flows from investing activities:
Purchases of property and equipment			(9,509)	(10,208)
Net cash used in investing activities			(9,509)	(10,208)
Cash flows from financing activities:
Proceeds from the exercise of share options			4	117
Payments of equity issuance costs			(910)	(16)
Net cash (used in) provided by financing activities			(906)	101
Effect of exchange rate changes on cash, cash equivalents and restricted cash			5,257	(39,459)
Net decrease in cash, cash equivalents and restricted cash			(125,912)	(147,308)
Cash, cash equivalents and restricted cash, beginning of period			382,761	310,676	$ 310,676
Cash, cash equivalents and restricted cash, end of period	256,849	163,368	256,849	163,368	382,761
Supplemental non-cash flow information
Property and equipment purchases included in accounts payable and accrued expenses			1,389	1,219
Right-of-use assets obtained in exchange for operating lease liabilities			41,211	57
Right of use assets terminated and obtained in exchange for operating lease liabilities, net			(1,110)	0
Capitalized implementation costs included in accrued expenses			74	31
Capitalized share-based compensation			19	0
Reconciliation of cash, cash equivalents and restricted cash reported within the condensed consolidated balance sheets:
Cash and cash equivalents	256,415	163,053	256,415	163,053	382,436
Restricted cash	434	315	434	315	325
Total cash, cash equivalents and restricted cash	$ 256,849	$ 163,368	$ 256,849	$ 163,368	$ 382,761

Nature of the Business

Nature of the Business	9 Months Ended
	Sep. 30, 2023
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Nature of the Business	Nature of the Business Autolus Therapeutics plc (the “Company”) is a biopharmaceutical company developing next-generation programmed T cell therapies for the treatment of cancer and autoimmune diseases. Using its broad suite of proprietary and modular T cell programming technologies, the Company is engineering precisely targeted, controlled and highly active T cell therapies that are designed to better recognize cancer cells, break down their defense mechanisms and attack and kill these cells. The Company believes its programmed T cell therapies have the potential to be best-in-class and to offer cancer patients substantial benefits over the existing standard of care, including the potential for cure in some patients. The Company is subject to risks and uncertainties common to early-stage companies in the biotechnology industry, including, but not limited to, development by competitors of new technological innovations, dependence on key personnel, protection of proprietary technology, compliance with government regulations and the ability to secure additional capital to fund operations. Product candidates currently under development will require significant additional research and development efforts, including precl inical and clinical testing and regulatory approval, prior to commercialization. These efforts require significant amounts of capital, adequate personnel and infrastructure and extensive compliance-reporting capabilities. Even if the Company’s product development efforts are successful, it is uncertain when, if ever, the Company will realize revenue from its product sales. The Company has funded its operations primarily with proceeds from the sale of equity securities through public offerings and sales pursuant to the Company's at-the-market facility, government grants, U.K. research and development tax credits and receipts from the U.K.'s Research and Development Expenditure Credit program ("RDEC"), out-licensing arrangements and strategic collaboration agreements.

Summary of Significant Accounti

Summary of Significant Accounting Policies	9 Months Ended
	Sep. 30, 2023
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	Summary of Significant Accounting Policies Basis of Presentation The accompanying unaudited condensed consolidated financial statements include those of the Company and its wholly owned subsidiaries, Autolus Holdings (UK) Limited, Autolus Limited, Autolus Inc. and Autolus GmbH, and have been prepared in conformity with accounting principles generally accepted in the United States of America (“U.S. GAAP”). All intercompany accounts and transactions have been eliminated upon consolidation. The significant accounting policies used in preparation of these unaudited condensed consolidated financial statements are consistent with those discussed in Note 2, “Summary of Significant Accounting Policies” in the Company’s Annual Report on Form 20-F for the year ended December 31, 2022 as filed with the Securities and Exchange Commission on March 7, 2023 (the “Annual Report”). In the opinion of management, all adjustments considered necessary to present fairly the results of the interim periods have been included and consist only of normal and recurring adjustments. Certain information and footnote disclosures have been condensed or omitted as permitted under U.S. GAAP. The results for the three and nine months ended September 30, 2023 are not necessarily indicative of the results to be expected for the year ending December 31, 2023, any other interim periods, or any future year or period. As such, the information included in these unaudited condensed consolidated financial statements should be read in conjunction with the audited consolidated financial statements and the related notes thereto as of and for the year ended December 31, 2022, included in the Annual Report. The Company has incurred recurring losses since its inception, including net losses of $45.8 million and $42.8 million for the three months ended September 30, 2023 and 2022, respectively and $131.2 million and $121.9 million for the nine months ended September 30, 2023 and 2022, respectively. The Company had an accumulated deficit of $801.4 million and $670.2 million as of September 30, 2023 and December 31, 2022, respectively. The Company expects to continue to generate operating losses in the foreseeable future. The Company’s inability to raise additional capital as and when needed could have a negative impact on its financial condition and ability to pursue its business strategies. There can be no assurances, however, that the current operating plan will be achieved or that additional funding will be available on terms acceptable to the Company, or at all. As of the date these unaudited condensed consolidated financial statements are issued, the Company expects that its cash and cash equivalents at September 30, 2023 of $256.4 million will be sufficient to fund the Company’s operations for at least twelve months from the issuance date of these unaudited condensed consolidated financial statements and accordingly they have been prepared on the going concern basis. Foreign Currency Translation The reporting currency of the Company is the U.S. dollar. The Company has determined the functional currency of the ultimate parent company, Autolus Therapeutics plc, is Pound Sterling. The functional currency of subsidiary operations is the applicable local currency. Monetary assets and liabilities denominated in currencies other than the functional currency are translated into the functional currency at rates of exchange prevailing at the balance sheet dates. Non-monetary assets and liabilities denominated in foreign currencies are translated into the functional currency at the exchange rates prevailing at the date of the transaction. Exchange gains or losses arising from foreign currency transactions are included in the determination of net income (loss) for the respective periods. The Company recorded foreign exchange losses of $1.7 million and $3.8 million for the three months ended September 30, 2023 and 2022, respectively, and foreign exchange losses of $0.4 million and $4.4 million for the nine months ended September 30, 2023 and 2022, respectively, which are included in other (expenses) income, net in the unaudited condensed consolidated statements of operations and comprehensive loss. Use of Estimates Lease Term—Impact on Right-of-Use Assets and Lease Liabilities In September 2021, the Company entered into an arrangement for lease with Forge Life Sciences Nominee, an affiliate of the Reef Group, for the design, construction and lease of the Company's new 70,000 square foot commercial manufacturing facility, referred to as, The Nucleus, in Stevenage, United Kingdom. Under this arrangement, the landlord leased the facility to the Company on agreed terms, upon satisfaction of certain conditions and completion of construction. Since November 2022, the landlord has handed over various portions of the facility to the Company until July 31, 2023 when the landlord and the Company accepted practical completion of The Nucleus. The Company was required to pay a pro-rated license fee for each portion of the facility which the Company has been granted access until execution of the lease agreement. As the landlord provided the Company with access to portions of the facility, the definition of a lease in accordance with ASC 842, was met. The lease term can materially impact the value of the right of use assets and lease liabilities recorded on our balance sheet as required under ASC 842. On September 19, 2023, the Company entered into a 20 year lease agreement with Forge Life Sciences Nominee for The Nucleus. The Company calculated the lease term for The Nucleus by taking into account, the noncancellable period specified in the agreement together with the periods a license fee was payable by the Company to the landlord for portions of The Nucleus handed over to the Company. Recent Accounting Pronouncements Not Yet Adopted

License Revenue

License Revenue	9 Months Ended
	Sep. 30, 2023
Revenue from Contract with Customer [Abstract]
License Revenue	License Revenue Revenue comprised of license revenue for the three and nine months ended September 30, 2023, and 2022 and is represented in the table below by geographical location (in thousands): Three Months Ended September 30, Nine Months Ended September 30, 2023 2022 2023 2022 License revenue United Kingdom $ 346 $ 60 $ 346 $ 60 United States $ 60 $ 2,309 $ 1,352 $ 2,309 Total license revenue $ 406 $ 2,369 $ 1,698 $ 2,369 Research, Option and License Agreement with Cabaletta: On January 9, 2023, the Company entered into an Option and License Agreement (the “Cabaletta Agreement”) with Cabaletta Bio Inc. (“Cabaletta”), pursuant to which the Company granted to Cabaletta a non-exclusive license to research, develop, manufacture, have manufactured, use, and commercialize products incorporating the Company's safety switch technology, “RQR8 technology”. Upon the execution of the Cabaletta Agreement, the Company made available the RQR8 licensed know-how to Cabaletta for a non-refundable license fee of $1.2 million. The Company has no further material performance obligations related to the Cabaletta Agreement. The Company further granted to Cabaletta the option to expand the rights and licenses granted hereunder to include the research, development, manufacture, use, or commercialization of licensed products up to a predetermined number of target options upon payment of an option exercise fee. The Company identified the following material promises relating to the granting of a non-exclusive license for research, development, manufacturing and commercialization activities as well as the initial transfer of know-how and information to Cabaletta. The Company determined the option exercise fee is not offered at a significant and incremental discount. Accordingly, the option granted to Cabaletta does not represent a material right and, therefore, is not a performance obligation at the outset of the arrangement. The Company determined that the granting of the research license and the initial transfer of know-how were not distinct from one another and must be combined as a performance obligation, as Cabaletta requires the know-how to derive benefit from the license. Based on these determinations, the Company identified one distinct performance obligation at the inception of the contract. The Company further determined that the license fee payable constituted the entirety of the consideration included in the transaction price at contract inception, which was allocated to the one performance obligation. The amount of the transaction price allocated to the performance obligation is recognized as or when the Company satisfies the performance obligation. The Company determined that the performance obligation was recognized at a point-in-time, upon the delivery of the transfer of know-how and research license to Cabaletta. No license revenue was recognized related to the Cabaletta Agreement for the three months ended September 30, 2023. The Company recognized total license revenue of $1.2 million, related to the Cabaletta Agreement for the nine months ended September 30, 2023. Upon execution of the Cabaletta Agreement, the transaction price included only the $1.2 million non-refundable license fee payable to the Company. The Company may receive further payments upon the exercise of the options for licensed targets, the achievement of certain development and sales milestones, as well as royalty payments based on net sales of each product covered by the licensed intellectual property. The future milestones, which represent variable consideration, will be evaluated under the most likely amount method, and were not included in the transaction price, as these amounts were fully constrained as of September 30, 2023. Research, Option and License Agreement with an Investee of Syncona Portfolio Limited The Company entered into a license agreement with an investee of Syncona Portfolio Limited on September 2, 2020. The terms of the agreement include a non-refundable license fee, payments based upon achievement of clinical development and regulatory objectives, and royalties on product sales. During the three and nine months ended September 30, 2023, Company received variable consideration arising from the achievement of a development milestone amounting to $0.35 million. Consequently, the Company recognized license revenue of $0.35 million (net of foreign exchange differences). Research, Option and License Agreement with Moderna: On June 22, 2021, the Company entered into a Research, Option and License Agreement (the “Moderna Agreement”) with ModernaTX, Inc. (“Moderna”), pursuant to which the Company granted to Moderna an exclusive research license to perform research and pre-clinical development activities relating to target sequences with respect to certain of the Company’s research targets and products. During the three and nine months ended September 30, 2022, Moderna exercised its option, pursuant to the terms of the Moderna Agreement, to license the Company’s proprietary binders against an undisclosed immuno-oncology target for the development and commercialization of mRNA therapeutics resulting in the Company recognizing $2.2 million (net of foreign exchange differences). The future milestones, which represent variable consideration, will be evaluated under the most likely amount method, and were not included in the transaction price, as these amounts were fully constrained as of September 30, 2023. For further details on the terms and accounting treatment considerations for the Moderna Agreement, please refer to Note 3, "Revenue" to the Company's consolidated financial statements contained in Company's Annual Report filed on March 7, 2023.

Prepaid Expenses and Other Curr

Prepaid Expenses and Other Current Assets	9 Months Ended
	Sep. 30, 2023
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]
Prepaid Expenses and Other Current Assets	Prepaid Expenses and Other Current Assets Prepaid expenses and other current assets consisted of the following (in thousands): September 30, December 31, 2023 2022 Research and development claims receivable $ 37,111 $ 24,685 Prepayments 7,535 12,337 VAT receivable 2,327 2,701 Other receivable 2,357 1,469 Deferred cost 1,911 1,494 Other assets 127 203 Accounts receivable 165 121 Total prepaid expenses and other current assets $ 51,533 $ 43,010

Property and Equipment, Net

Property and Equipment, Net	9 Months Ended
	Sep. 30, 2023
Property, Plant and Equipment [Abstract]
Property and Equipment, Net	Property and Equipment, Net Property and equipment, net consisted of the following (in thousands): September 30, December 31, 2023 2022 Lab equipment $ 26,362 $ 31,188 Office equipment 4,416 3,573 Furniture and fixtures 1,982 1,221 Leasehold improvements 12,655 13,583 Assets under construction 18,239 13,186 Less: accumulated depreciation (29,017) (27,542) Total property and equipment, net $ 34,637 $ 35,209 Depreciation expense for the three months ended September 30, 2023 and 2022 was $1.4 million and $1.8 million, respectively, and for the nine months ended September 30, 2023 and 2022 was $4.8 million and $5.7 million, respectively.

Accrued Expenses and Other Liab

Accrued Expenses and Other Liabilities	9 Months Ended
	Sep. 30, 2023
Payables and Accruals [Abstract]
Accrued Expenses and Other Liabilities	Accrued Expenses and Other Liabilities Accrued expenses and other liabilities consisted of the following (in thousands): September 30, December 31, 2023 2022 Research and development costs $ 17,863 $ 26,478 Compensation and benefits 10,169 10,181 Professional fees 2,873 3,745 Other liabilities 483 393 Total accrued expenses and other liabilities $ 31,388 $ 40,797

Shareholders_ Equity

Shareholders’ Equity	9 Months Ended
	Sep. 30, 2023
Equity [Abstract]
Shareholders’ Equity	Shareholders’ Equity Ordinary Shares Each holder of ordinary shares is entitled to one vote per ordinary share and to receive dividends when and if such dividends are recommended by the Company's board of directors and declared by the shareholders. As of September 30, 2023, the Company has not declared any dividends. December 2022 Public Offering In December 2022, the Company completed an underwritten public offering of 81,927,012 ADSs representing 81,927,012 ordinary shares, which includes the partial exercise by the underwriters of an option to purchase an additional 6,927,012 ADSs, at a public offering price of $2.00 per ADS. Aggregate net proceeds to the Company, after underwriting discounts and offering expenses, were $152.4 million. Restricted stock units At September 30, 2023, 56,269 ordinary shares underlying restricted stock unit awards have vested, however, these restricted stock unit awards have not been issued and, as such are not included in the calculation of the Company's outstanding shares at September 30, 2023. Subsequent to September 30, 2023, 52,363 ordinary shares underlying restricted stock unit awards have been issued.

Share-based Compensation Expens

Share-based Compensation Expense	9 Months Ended
	Sep. 30, 2023
Share-Based Payment Arrangement [Abstract]
Share-based Compensation Expense	Share-based Compensation Expense Share-based compensation expense recorded as research and development expenses, general and administrative expenses and capitalized is as follows (in thousands): Three Months Ended September 30, Nine Months Ended September 30, 2023 2022 2023 2022 Research and development $ 1,525 $ 1,831 $ 4,982 $ 4,802 General and administrative 1,335 1,506 2,947 3,797 Capitalized 4 — 19 — Total share-based compensation $ 2,864 $ 3,337 $ 7,948 $ 8,599

Net loss per share

Net loss per share	9 Months Ended
	Sep. 30, 2023
Earnings Per Share [Abstract]
Net loss per share	Net loss per share Basic and diluted net loss per share attributable to ordinary shareholders was calculated as follows (in thousands, except share and per share amounts): Three Months Ended September 30, Nine Months Ended September 30, 2023 2022 2023 2022 Numerator Net loss $ (45,849) $ (42,767) $ (131,212) $ (121,888) Net loss attributable to ordinary shareholders - basic and diluted $ (45,849) $ (42,767) $ (131,212) $ (121,888) Denominator Weighted-average number of ordinary shares used in net loss per share - basic and diluted 173,984,101 91,240,801 173,890,666 91,028,562 Basic and diluted net loss per ordinary share $ (0.26) $ (0.47) $ (0.75) $ (1.34) For all periods presented, outstanding but unvested restricted shares and share options have been excluded from the calculation, because their effects would be anti-dilutive. Therefore, the weighted average number of ordinary shares used to calculate both basic and diluted loss per share is the same for all periods presented. The following potentially dilutive securities have been excluded from the calculation of diluted net loss per share due to their anti-dilutive effect: Three and Nine Months Ended September 30, 2023 2022 Unvested restricted shares and units 264,326 996,927 Share options 14,074,842 10,421,137 Warrants 3,265,306 3,265,306 Total potentially dilutive securities 17,604,474 14,683,370

Liability related to sales of f

Liability related to sales of future royalties and sales milestones, net	9 Months Ended
	Sep. 30, 2023
Investments, Debt and Equity Securities [Abstract]
Liability related to sales of future royalties and sales milestones, net	Liability related to future royalties and sales milestones, net On November 6, 2021, the Company concurrently entered into the following agreements with BXLS V - Autobahn L.P, ("Blackstone"): (i) Strategic Collaboration Agreement (the “Blackstone Collaboration Agreement"), (ii) Securities Purchase Agreement (the “Blackstone Securities Purchase Agreement”), (iii) Warrant Agreement (the “Blackstone Warrant”) and (iv) a Registration Rights Agreement (the “Blackstone Registration Rights Agreement”). The Blackstone Collaboration Agreement, the Blackstone Securities Purchase Agreement, the Blackstone Warrant and the Blackstone Registration Rights Agreement are collectively referred to as the "Blackstone Agreements". The Blackstone Agreements were entered into and in contemplation of one another and, accordingly, the Company assessed the accounting for the Blackstone Agreements in the aggregate. For further details on the terms and accounting treatment considerations for these contracts, please refer to following notes to the Company's consolidated financial statements contained in the Company's Annual Report: • Note 2, "Summary of significant accounting policies" • Note 8, “Liability related to future royalties and sales milestones, net” • Note 9, "Warrants" • Note 10, "Shareholders' equity" In November 2021, the upfront payment of $50 million was paid by Blackstone upon execution of the Blackstone Collaboration Agreement. In December 2022, two Blackstone Development Payments were paid by Blackstone of $35 million each as a result of (i) the joint steering committee’s review of the Company’s interim analysis of pivotal FELIX Phase 2 clinical trial of obe-cel in relapsed/refractory (r/r) adult Acute Lymphoblastic Leukemia (ALL) and (ii) achievement of a pre-agreed manufacturing milestone as a result of completion of planned activities demonstrating the performance and qualification of the Company’s obe-cel’s manufacturing process. The remaining $30 million will be payable to the Company on the achievement on certain specified regulatory milestones. The Company considers the achievement of the specified regulatory milestone as probable when actually achieved. The carrying amount of the Blackstone Collaboration Agreement liability is based on the Company’s estimate of the future royalties and sales milestones to be paid to Blackstone and the Blackstone Development payment to be received over the life of the arrangement as discounted using an effective interest rate. The excess estimated present value of future royalties and sales milestone payments over the initial carrying amount and future Blackstone Development Payments received, is recognized as a cumulative catch-up method within interest expense using the initial effective interest rate. The imputed rate of interest on the unamortized portion of the Blackstone Collaboration Agreement liability was approximately 15.80% as of September 30, 2023 and December 31, 2022, respectively. On a quarterly basis, the Company assesses the amount and timing of expected royalty and sales milestone payments using a combination of internal projections and forecasts from external sources. To the extent the present value of such payments are greater or less than its initial estimates or the timing of such payments is materially different than its original estimates, the Company will adjust the amortization of the Blackstone Collaboration Agreement liability using the catch-up method. During the three and nine months ended September 30, 2023, there have been no changes to the estimates used in the determination of the carrying amount of the Blackstone Collaboration Agreement liability. There are a number of factors that could materially affect the probability, amount and timing of royalty and sales milestone payments to be made by the Company and Blackstone Development payment to be received from Blackstone, respectively, most of which are not within the Company’s control. The Blackstone Collaboration Agreement liability is recognized using significant unobservable inputs. These inputs are derived using internal management estimates developed based on third party data and reflect management’s judgements, current market conditions surrounding competing products, and forecasts. The significant unobservable inputs include regulatory approvals, estimated patient populations, estimated selling price, estimated sales, estimated peak sales and sales ramp, timing of the expected launch and its impact on the royalties as well as the overall probability of a success. Changes to the Blackstone Collaboration Agreement liability related to future royalties and sales milestones are as follows: Amount in thousands Balance at December 31, 2021 $ 47,016 Proceeds from Blackstone Development Payments received 70,000 Interest expense accrued on liability related to future royalties and sales milestones, net 8,005 Cumulative catch-up adjustment 879 Balance at December 31, 2022 $ 125,900 Interest expense accrued on liability related to future royalties and sales milestones, net 14,878 Balance at September 30, 2023 $ 140,778

Leases

Leases	9 Months Ended
	Sep. 30, 2023
Leases [Abstract]
Leases	Leases The Company leases certain office space, laboratory space, and equipment. At the inception of an arrangement, the Company determines whether the arrangement is or contains a lease based on the unique facts and circumstances present. Operating Leases In September 2017, the Company executed an arrangement with Cell Therapy Catapult Limited to lease a manufacturing suite at the Cell and Gene Therapy Catapult manufacturing center in Stevenage, United Kingdom for a term through May 2021, at which time the Company had the option to renew or terminate the lease. The lease had a six-month rent-free period. In December 2018, the Company executed an additional lease arrangement for additional manufacturing space for a term through September 2023, at which time the Company has the option to renew or terminate the lease. In addition, in May 2020, the Company executed an arrangement with Cell Therapy Catapult Limited to lease a manufacturing suite at the Cell and Gene Therapy Catapult manufacturing center in Stevenage, United Kingdom for a term through April 2024. In July 2022, the Company and Cell Therapy Catapult Limited mutually agreed: (i) to extend the lease term of a manufacturing suite leased by the Company from April 2024 to February 2025, and (ii) to reduce the lease term of a different manufacturing suite leased by the Company from July 2024 to June 2023. In March 2023, the Company and Cell Therapy Catapult Limited mutually agreed: (i) to terminate the lease relating to the leased manufacturing suite which originally had a lease term until February 2025, (ii) to extend the lease term of one of the remaining manufacturing suites from June 2023 to August 2024, and (iii) to extend the lease term of a third manufacturing suite leased by the Company from September 2023 to August 2024. The Company recognized a lease termination loss of $0.1 million for the nine months ended September 30, 2023 related to the manufacturing suite terminated and exited on March 31, 2023. In addition, during the nine months ended September 30, 2023, the Company recognized a loss on disposal on leasehold improvements of $3.8 million arising from the manufacturing suite terminated and exited on March 31, 2023. In October 2018, the Company executed an agreement to sublease office space in Rockville, Maryland for a term through October 2021. The Company then terminated the sublease in February 2020 and immediately entered into a five-year lease for the same space with the landlord. The lease related to this facility is classified as an operating lease. In January 2019, the Company executed a lease agreement with Whitewood Media Village GP Limited and Whitewood Media Village Nominee Limited to lease the fifth floor of MediaWorks including laboratory space. In August 2021, MediaWorks became the Company's main corporate headquarters. The lease term is nine years and eleven months with an eighteen-month rent free period at the beginning of the lease term. The Company has the option to terminate the lease in November 2026. In February 2019, the Company entered into a fifteen-year lease for three manufacturing units in Enfield, United Kingdom with option to terminate the lease in February 2029. In addition to base rent, the Company is obligated to pay its proportionate share of building operating expenses and real estate taxes in excess of base year amounts. In March 2021, one of the units was split into two separate units and the Company surrendered one of the units. Upon the surrender, the Company recognized a $0.1 million gain in other (expense) income after recognizing a termination fee of $0.2 million. The Company has no further obligations for the surrendered unit and the right of use asset and lease liability which were recorded for this unit have been written off in the relevant period. The Company subleased two of the three units to third parties with lease terms ranging from October, 2021 to February 2029 and October 2026, respectively. The Company is actively seeking to sublease or assign the lease arrangements relating to the final unit. The Company completed an asset impairment analysis of the right-of-use lease concluding the undiscounted cash flows exceeded the carrying value as of September 30, 2023. In September 2021, the Company entered into an arrangement for lease with the landlord, Forge Life Sciences Nominee, an affiliate of the Reef Group, for the design, construction and lease of a new 70,000 square foot commercial manufacturing facility in Stevenage, United Kingdom. Under this arrangement, the landlord leased the facility, which will be called The Nucleus, to the Company on agreed terms, upon satisfaction of certain conditions and completion of construction. Since November 2022, the landlord has handed over various portions of the facility to the Company until July 31, 2023 when the landlord and the Company accepted practical completion of The Nucleus. The Company is required to pay a pro-rated license fee for each portion of the facility which the Company has been granted access until the execution of a lease agreement. The Company cumulatively contributed $7.5 million as part as of landlord works and tenant contributions towards the lease as of September 30, 2023 resulting in these payments being taken into account in the determination of the right of use asset for this facility. On July 31, 2023, the landlord and its contractors accepted practical completion of The Nucleus. On September 19, 2023, the Company entered into a 20 year lease agreement with the landlord for The Nucleus. The Company made fit-out costs in other areas of the building and will be required to be removed at the end of the lease term. As a result, as of September 30, 2023, the Company has recognized an estimated Asset Retirement Obligation ("ARO") amounting to $0.1 million. The following table contains a summary of the lease costs recognized under Accounting Standards Update, "ASU" 2016-02 and other information pertaining to the Company’s operating leases for three and nine months ended September 30, 2023 and 2022 (in thousands): Three Months Ended September 30, Nine Months Ended September 30, Lease costs 2023 2022 2023 2022 Operating lease costs $ 2,061 $ 1,103 $ 5,235 $ 3,542 Variable costs 573 268 657 720 Short term lease costs 227 119 451 231 Total lease costs $ 2,861 $ 1,490 $ 6,343 $ 4,493 Nine Months Ended September 30, Other information 2023 2022 Cash paid for amounts included in the measurement of lease liabilities: Operating cash outflows from operating leases (in thousands) $ 7,817 $ 3,740 Weighted-average remaining lease term - operating leases (in years) 15.9 years 5.1 years Weighted-average discount rate - operating leases 7.44 % 7.18 % Future fixed payments for non-cancellable operating leases in effect as of September 30, 2023 are payable as follows (in thousands): Remainder of 2023 $ 1,975 2024 8,062 2025 6,625 2026 6,396 2027 6,255 Thereafter 60,424 Total lease payments 89,737 Less: imputed interest (37,279) Present value of lease liabilities $ 52,458 Sublease Agreements In October 2021, the Company entered into two separate sublease agreements with two third parties for two manufacturing spaces in Enfield which are currently leased by the Company. The annual lease payments to be received for each of the subleased units are £97,000 and £109,000, over lease terms from October 2021 to February 2029 and October 2021 to October 2026, respectively. In October 2021, the Company received $0.1 million in rental deposits, arising from the sub-lease agreements which have been classified as restricted cash as of September 30, 2023 and December 31, 2022, respectively. Both subleases have been classified as operating leases. The Company recognized the sublease payments on a straight-line basis from the commencement of the sublease agreements. The following table shows the sublease rental income for the three and nine months ended September 30, 2023 and 2022 (in thousands): Three Months Ended September 30, Nine Months Ended September 30, Sublease rental income 2023 2022 2023 2022 Sublease rental income (included in other income (expenses), net) $ 61 $ 57 $ 181 $ 183 Total sublease rental income $ 61 $ 57 $ 181 $ 183 Future fixed receipts for non-cancellable operating subleases in effect as of September 30, 2023 are receivable as follows (in thousands): Remainder of 2023 $ 65 2024 $ 261 2025 $ 261 2026 $ 203 2027 $ 123 Thereafter $ 106 Total lease payments receivable $ 1,019

Commitments and Contingencies

Commitments and Contingencies	9 Months Ended
	Sep. 30, 2023
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Commitments and Contingencies License Agreements The Company has entered into an exclusive license agreement with UCL Business Ltd, ("UCLB") which has subsequently been amended and restated. In connection with the UCLB license agreement, the Company is required to make annual license payments and may be required to make payments to UCLB upon the achievement of specified milestones. During the three and nine months ended September 30, 2023, less than $0.1 million and $0.2 million was paid or payable to UCLB by the Company, respectively, relating to the income allocable to the value of the sublicensed intellectual property rights. In November 2019, the Company entered into an exclusive license agreement with Noile-Immune Biotech Inc. ("Noile") under which the Company will have the right to develop CAR T cell therapies incorporating Noile’s PRIME (proliferation-inducing and migration-enhancing) technology. The Company may be obligated to make additional payments to Noile upon the achievement of development milestones and receipt of regulatory approvals product sale milestones, as well as royalty payments based on possible future sales resulting from the utilization of the licensed technology. In July 2022, the Company renegotiated a master services agreement with Adaptive Biotechnologies Corporation ("Adaptive"), under which Adaptive's assay is used to analyze patient samples from relapsed/refractory B Cell Acute Lymphoblastic Leukemia (rrB-ALL) patients. Under the agreement, the Company is obligated to make specified payments to Adaptive upon the achievement and receipt of certain regulatory approvals and achievement of commercial milestones in connection with the Company's use of the Adaptive assay. In September 2023, the Company entered into a non-exclusive sublicense agreement with Miltenyi Biotech B.V. & Co. KG ("Miltenyi") under which the Company will have the right to develop, manufacture and use Miltenyi's or affiliates' sublicensed products. Under the agreement, the Company is obligated to make specified payments to Miltenyi upon the achievement of certain regulatory and clinical milestones. The Company recognized $0.4 million in aggregate relating to an upfront license payment and milestone payment which was deemed probable during the three and nine months ended September 30, 2023. The Company recognizes the regulatory, clinical and commercial milestones when probable . The Company concluded that, as of September 30, 2023, there were no other milestones for which the likelihood of achievement was currently probable relating to either of the UCLB, Noile, Adaptive or Miltenyi contracts. Legal Proceedings From time to time, the Company may be a party to litigation or subject to claims incident to the ordinary course of business. Regardless of the outcome, litigation can have an adverse impact on the Company because of defense and settlement costs, diversion of management resources and other factors. The Company was not a party to any litigation and did not have contingency reserves established for any liabilities as of September 30, 2023 and December 31, 2022. Capital Commitments As of September 30, 2023, the Company’s unconditional purchase obligations for capital expenditure totaled $4.2 million and include signed orders for capital equipment and capital expenditure for construction and related expenditure relating to its properties in the United Kingdom and the United States. Blackstone Strategic Collaboration and Financing Agreement Refer to Note 10, "Liability related to future royalties and sales milestone, net" for further details to the Blackstone Collaboration Agreement . Leases Lease payments under operating leases as of September 30, 2023 and information about the Company’s lease arrangements are disclosed in Note 11, "Leases".

Related parties

Related parties	9 Months Ended
	Sep. 30, 2023
Related Party Transactions [Abstract]
Related parties	Related parties Blackstone Agreements In November 2021, the Company concurrently entered into the Blackstone Agreements. Subsequent to the execution of the Blackstone Agreements, Blackstone became a related party of the Company. Blackstone owns more than 10% of the Company's outstanding voting securities and is therefore one of the principal owners of the Company. In addition, Blackstone received and exercised their right to nominate one director to the board of directors of the Company. As of September 30, 2023, the carrying amount of the Blackstone Collaboration Agreement liability was $140.8 million which included aggregated cumulative non-cash interest expense and cumulative catch-up adjustment of $24.9 million. As of December 31, 2022, the carrying amount of the Blackstone Collaboration Agreement liability was $125.9 million which included aggregated cumulative non-cash interest expense (including cumulative catch-up adjustments), of $10.0 million. Refer to Note 10, " Liability related to sales of future royalties and sales milestone, net " for further details. Syncona Portfolio Limited Syncona Portfolio Limited is a related party of the Company as Syncona Portfolio Limited owns more than 10% of the Company's outstanding voting securities and is therefore one of the principal owners of the Company. In addition, the chair of the ultimate parent company of Syncona Portfolio Limited is also a director of the Company. December 2022 public offering In connection with the Company’s December 2022 public offering, certain of the Company's related parties purchased the Company's ADSs from the underwriters at the public offering price of $2.00 per ADSs, and on the same terms as other investors in the Company's public offering. The following table summarizes purchases of ADS by the Company's related parties: Related party ADSs purchased Total purchase price (in millions) Syncona Portfolio Limited (1) 14,000,000 $ 28.0 Deep Track Capital, LP (2) 15,000,000 30.0 Qatar Investment Authority (3) 15,000,000 30.0 Armistice Capital, LLC (4) 10,000,000 20.0 Entities affiliated with Blackstone (5) 2,500,000 5.0 56,500,000 $ 113.0 (1) Syncona Portfolio Limited is a holder of more than 10% of the Company's share capital. (2) In connection with this transaction, Deep Track Capital, LP became a holder of more than 5% of the Company's share capital. (3) In connection with this transaction, Qatar Investment Authority became a holder of more than 5% of the Company's share capital. (4) In connection with this transaction, Armistice Capital, LLC became a holder of more than 5% of the Company's share capital. (5) Entities affiliated with Blackstone collectively hold more than 10% of the Company's share capital. Investee of Syncona Portfolio Limited The Company entered into a license agreement with an investee of Syncona Portfolio Limited on September 2, 2020. In addition, the chair of the ultimate parent company of Syncona Portfolio Limited is also a director of the Company. The terms of the agreement include a non-refundable license fee, payments based upon achievement of clinical development and regulatory objectives, and royalties on product sales. During the three and nine months ended September 30, 2023, Company received variable consideration arising from the achievement of a development milestone amounting to $0.35 million. Consequently, the Company recognized license revenue of $0.35 million (net of foreign exchange differences).

Subsequent Events

Subsequent Events	9 Months Ended
	Sep. 30, 2023
Subsequent Events [Abstract]
Subsequent Events	Subsequent Events The Company evaluated subsequent events through November 9, 2023, the date on which these unaudited condensed consolidated financial statements were is sued. The Company has concluded that no subsequent event has occurred that requires disclosure.

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policies)	9 Months Ended
	Sep. 30, 2023
Accounting Policies [Abstract]
Basis of Presentation	Basis of Presentation The accompanying unaudited condensed consolidated financial statements include those of the Company and its wholly owned subsidiaries, Autolus Holdings (UK) Limited, Autolus Limited, Autolus Inc. and Autolus GmbH, and have been prepared in conformity with accounting principles generally accepted in the United States of America (“U.S. GAAP”). All intercompany accounts and transactions have been eliminated upon consolidation. The significant accounting policies used in preparation of these unaudited condensed consolidated financial statements are consistent with those discussed in Note 2, “Summary of Significant Accounting Policies” in the Company’s Annual Report on Form 20-F for the year ended December 31, 2022 as filed with the Securities and Exchange Commission on March 7, 2023 (the “Annual Report”). In the opinion of management, all adjustments considered necessary to present fairly the results of the interim periods have been included and consist only of normal and recurring adjustments. Certain information and footnote disclosures have been condensed or omitted as permitted under U.S. GAAP. The results for the three and nine months ended September 30, 2023 are not necessarily indicative of the results to be expected for the year ending December 31, 2023, any other interim periods, or any future year or period. As such, the information included in these unaudited condensed consolidated financial statements should be read in conjunction with the audited consolidated financial statements and the related notes thereto as of and for the year ended December 31, 2022, included in the Annual Report. The Company has incurred recurring losses since its inception, including net losses of $45.8 million and $42.8 million for the three months ended September 30, 2023 and 2022, respectively and $131.2 million and $121.9 million for the nine months ended September 30, 2023 and 2022, respectively. The Company had an accumulated deficit of $801.4 million and $670.2 million as of September 30, 2023 and December 31, 2022, respectively. The Company expects to continue to generate operating losses in the foreseeable future. The Company’s inability to raise additional capital as and when needed could have a negative impact on its financial condition and ability to pursue its business strategies. There can be no assurances, however, that the current operating plan will be achieved or that additional funding will be available on terms acceptable to the Company, or at all. As of the date these unaudited condensed consolidated financial statements are issued, the Company expects that its cash and cash equivalents at September 30, 2023 of $256.4 million will be sufficient to fund the Company’s operations for at least twelve months from the issuance date of these unaudited condensed consolidated financial statements and accordingly they have been prepared on the going concern basis.
Foreign Currency Translation	Foreign Currency Translation The reporting currency of the Company is the U.S. dollar. The Company has determined the functional currency of the ultimate parent company, Autolus Therapeutics plc, is Pound Sterling. The functional currency of subsidiary operations is the applicable local currency. Monetary assets and liabilities denominated in currencies other than the functional currency are translated into the functional currency at rates of exchange prevailing at the balance sheet dates. Non-monetary assets and liabilities denominated in foreign currencies are translated into the functional currency at the exchange rates prevailing at the date of the transaction.
Use of Estimates	Use of Estimates Lease Term—Impact on Right-of-Use Assets and Lease Liabilities In September 2021, the Company entered into an arrangement for lease with Forge Life Sciences Nominee, an affiliate of the Reef Group, for the design, construction and lease of the Company's new 70,000 square foot commercial manufacturing facility, referred to as, The Nucleus, in Stevenage, United Kingdom. Under this arrangement, the landlord leased the facility to the Company on agreed terms, upon satisfaction of certain conditions and completion of construction. Since November 2022, the landlord has handed over various portions of the facility to the Company until July 31, 2023 when the landlord and the Company accepted practical completion of The Nucleus. The Company was required to pay a pro-rated license fee for each portion of the facility which the Company has been granted access until execution of the lease agreement. As the landlord provided the Company with access to portions of the facility, the definition of a lease in accordance with ASC 842, was met. The lease term can materially impact the value of the right of use assets and lease liabilities recorded on our balance sheet as required under ASC 842. On September 19, 2023, the Company entered into a 20 year lease agreement with Forge Life Sciences Nominee for The Nucleus. The Company calculated the lease term for The Nucleus by taking into account, the noncancellable period specified in the agreement together with the periods a license fee was payable by the Company to the landlord for portions of The Nucleus handed over to the Company.
Recent Accounting Pronouncements Not Yet Adopted	Recent Accounting Pronouncements Not Yet AdoptedThere are no new accounting pronouncements that have been issued by the Financial Accounting Standards Board, “FASB”, that are applicable to the Company.

License Revenue (Tables)

License Revenue (Tables)	9 Months Ended
	Sep. 30, 2023
Revenue from Contract with Customer [Abstract]
Schedule of Revenue by Geographic Locations	Revenue comprised of license revenue for the three and nine months ended September 30, 2023, and 2022 and is represented in the table below by geographical location (in thousands): Three Months Ended September 30, Nine Months Ended September 30, 2023 2022 2023 2022 License revenue United Kingdom $ 346 $ 60 $ 346 $ 60 United States $ 60 $ 2,309 $ 1,352 $ 2,309 Total license revenue $ 406 $ 2,369 $ 1,698 $ 2,369

Prepaid Expenses and Other Cu_2

Prepaid Expenses and Other Current Assets (Tables)	9 Months Ended
	Sep. 30, 2023
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]
Schedule of Prepaid Expenses and Other Current Assets	Prepaid expenses and other current assets consisted of the following (in thousands): September 30, December 31, 2023 2022 Research and development claims receivable $ 37,111 $ 24,685 Prepayments 7,535 12,337 VAT receivable 2,327 2,701 Other receivable 2,357 1,469 Deferred cost 1,911 1,494 Other assets 127 203 Accounts receivable 165 121 Total prepaid expenses and other current assets $ 51,533 $ 43,010

Property and Equipment, Net (Ta

Property and Equipment, Net (Tables)	9 Months Ended
	Sep. 30, 2023
Property, Plant and Equipment [Abstract]
Schedule of Depreciation	Property and equipment, net consisted of the following (in thousands): September 30, December 31, 2023 2022 Lab equipment $ 26,362 $ 31,188 Office equipment 4,416 3,573 Furniture and fixtures 1,982 1,221 Leasehold improvements 12,655 13,583 Assets under construction 18,239 13,186 Less: accumulated depreciation (29,017) (27,542) Total property and equipment, net $ 34,637 $ 35,209

Accrued Expenses and Other Li_2

Accrued Expenses and Other Liabilities (Tables)	9 Months Ended
	Sep. 30, 2023
Payables and Accruals [Abstract]
Schedule of Accrued Expenses and Other Liabilities	Accrued expenses and other liabilities consisted of the following (in thousands): September 30, December 31, 2023 2022 Research and development costs $ 17,863 $ 26,478 Compensation and benefits 10,169 10,181 Professional fees 2,873 3,745 Other liabilities 483 393 Total accrued expenses and other liabilities $ 31,388 $ 40,797

Share-based Compensation Expe_2

Share-based Compensation Expense (Tables)	9 Months Ended
	Sep. 30, 2023
Share-Based Payment Arrangement [Abstract]
Schedule of Share Based Compensation Expense	Share-based compensation expense recorded as research and development expenses, general and administrative expenses and capitalized is as follows (in thousands): Three Months Ended September 30, Nine Months Ended September 30, 2023 2022 2023 2022 Research and development $ 1,525 $ 1,831 $ 4,982 $ 4,802 General and administrative 1,335 1,506 2,947 3,797 Capitalized 4 — 19 — Total share-based compensation $ 2,864 $ 3,337 $ 7,948 $ 8,599

Net loss per share (Tables)

Net loss per share (Tables)	9 Months Ended
	Sep. 30, 2023
Earnings Per Share [Abstract]
Schedule of Earnings Per Share, Basic and Diluted	Basic and diluted net loss per share attributable to ordinary shareholders was calculated as follows (in thousands, except share and per share amounts): Three Months Ended September 30, Nine Months Ended September 30, 2023 2022 2023 2022 Numerator Net loss $ (45,849) $ (42,767) $ (131,212) $ (121,888) Net loss attributable to ordinary shareholders - basic and diluted $ (45,849) $ (42,767) $ (131,212) $ (121,888) Denominator Weighted-average number of ordinary shares used in net loss per share - basic and diluted 173,984,101 91,240,801 173,890,666 91,028,562 Basic and diluted net loss per ordinary share $ (0.26) $ (0.47) $ (0.75) $ (1.34)
Schedule of Anti-dilutive Securities	The following potentially dilutive securities have been excluded from the calculation of diluted net loss per share due to their anti-dilutive effect: Three and Nine Months Ended September 30, 2023 2022 Unvested restricted shares and units 264,326 996,927 Share options 14,074,842 10,421,137 Warrants 3,265,306 3,265,306 Total potentially dilutive securities 17,604,474 14,683,370

Liability related to sales of_2

Liability related to sales of future royalties and sales milestones, net (Tables)	9 Months Ended
	Sep. 30, 2023
Investments, Debt and Equity Securities [Abstract]
Liability Related Debt Arising Financial Agreement	Changes to the Blackstone Collaboration Agreement liability related to future royalties and sales milestones are as follows: Amount in thousands Balance at December 31, 2021 $ 47,016 Proceeds from Blackstone Development Payments received 70,000 Interest expense accrued on liability related to future royalties and sales milestones, net 8,005 Cumulative catch-up adjustment 879 Balance at December 31, 2022 $ 125,900 Interest expense accrued on liability related to future royalties and sales milestones, net 14,878 Balance at September 30, 2023 $ 140,778

Leases (Tables)

Leases (Tables)	9 Months Ended
	Sep. 30, 2023
Leases [Abstract]
Lease Cost	The following table contains a summary of the lease costs recognized under Accounting Standards Update, "ASU" 2016-02 and other information pertaining to the Company’s operating leases for three and nine months ended September 30, 2023 and 2022 (in thousands): Three Months Ended September 30, Nine Months Ended September 30, Lease costs 2023 2022 2023 2022 Operating lease costs $ 2,061 $ 1,103 $ 5,235 $ 3,542 Variable costs 573 268 657 720 Short term lease costs 227 119 451 231 Total lease costs $ 2,861 $ 1,490 $ 6,343 $ 4,493 Nine Months Ended September 30, Other information 2023 2022 Cash paid for amounts included in the measurement of lease liabilities: Operating cash outflows from operating leases (in thousands) $ 7,817 $ 3,740 Weighted-average remaining lease term - operating leases (in years) 15.9 years 5.1 years Weighted-average discount rate - operating leases 7.44 % 7.18 %
Lease Maturity Schedule	Future fixed payments for non-cancellable operating leases in effect as of September 30, 2023 are payable as follows (in thousands): Remainder of 2023 $ 1,975 2024 8,062 2025 6,625 2026 6,396 2027 6,255 Thereafter 60,424 Total lease payments 89,737 Less: imputed interest (37,279) Present value of lease liabilities $ 52,458
Sublease Classification	The following table shows the sublease rental income for the three and nine months ended September 30, 2023 and 2022 (in thousands): Three Months Ended September 30, Nine Months Ended September 30, Sublease rental income 2023 2022 2023 2022 Sublease rental income (included in other income (expenses), net) $ 61 $ 57 $ 181 $ 183 Total sublease rental income $ 61 $ 57 $ 181 $ 183
Lease Receivable Maturity Schedule	Future fixed receipts for non-cancellable operating subleases in effect as of September 30, 2023 are receivable as follows (in thousands): Remainder of 2023 $ 65 2024 $ 261 2025 $ 261 2026 $ 203 2027 $ 123 Thereafter $ 106 Total lease payments receivable $ 1,019

Related parties (Tables)

Related parties (Tables)	9 Months Ended
	Sep. 30, 2023
Related Party Transactions [Abstract]
Summary of ADSs	The following table summarizes purchases of ADS by the Company's related parties: Related party ADSs purchased Total purchase price (in millions) Syncona Portfolio Limited (1) 14,000,000 $ 28.0 Deep Track Capital, LP (2) 15,000,000 30.0 Qatar Investment Authority (3) 15,000,000 30.0 Armistice Capital, LLC (4) 10,000,000 20.0 Entities affiliated with Blackstone (5) 2,500,000 5.0 56,500,000 $ 113.0 (1) Syncona Portfolio Limited is a holder of more than 10% of the Company's share capital. (2) In connection with this transaction, Deep Track Capital, LP became a holder of more than 5% of the Company's share capital. (3) In connection with this transaction, Qatar Investment Authority became a holder of more than 5% of the Company's share capital. (4) In connection with this transaction, Armistice Capital, LLC became a holder of more than 5% of the Company's share capital. (5) Entities affiliated with Blackstone collectively hold more than 10% of the Company's share capital.

Summary of Significant Accoun_3

Summary of Significant Accounting Policies - Narrative (Details) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2023 USD ($)	Sep. 30, 2022 USD ($)	Sep. 30, 2023 USD ($)	Sep. 30, 2022 USD ($)	Sep. 19, 2023	Dec. 31, 2022 USD ($)	Sep. 30, 2021 ft²
Lessee, Lease, Description [Line Items]
Net loss	$ (45,849)	$ (42,767)	$ (131,212)	$ (121,888)
Accumulated deficit	(801,391)		(801,391)			$ (670,179)
Cash and cash equivalents	256,415	163,053	256,415	163,053		$ 382,436
Foreign currency gain (loss)	$ (1,700)	$ (3,800)	$ (400)	$ (4,400)
Manufacturing Suite in Stevenage, United Kingdom
Lessee, Lease, Description [Line Items]
Number of square feet | ft²							70,000
Operating lease contract term (in years)					20 years

License Revenue - Disaggregatio

License Revenue - Disaggregation of Revenue (Details) - License revenue - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Disaggregation of Revenue [Line Items]
Total license revenue	$ 406	$ 2,369	$ 1,698	$ 2,369
United Kingdom
Disaggregation of Revenue [Line Items]
Total license revenue	346	60	346	60
United States
Disaggregation of Revenue [Line Items]
Total license revenue	$ 60	$ 2,309	$ 1,352	$ 2,309

License revenue - Narrative (De

License revenue - Narrative (Details)		3 Months Ended			6 Months Ended	9 Months Ended
	Jan. 09, 2023 USD ($)	Sep. 30, 2023 USD ($) performanceObligation	Jun. 30, 2023 USD ($)	Sep. 30, 2022 USD ($)	Jun. 30, 2023 USD ($)	Sep. 30, 2023 USD ($) performanceObligation	Sep. 30, 2022 USD ($)
Disaggregation of Revenue [Line Items]
Distinct performance obligation | performanceObligation		1				1
License revenue
Disaggregation of Revenue [Line Items]
Revenue from contract with customer		$ 406,000		$ 2,369,000		$ 1,698,000	$ 2,369,000
License revenue | Cabaletta Bio Inc. (“Cabaletta”)
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	$ 1,200,000		$ 0		$ 1,200,000
License revenue | Investee of Syncona
Disaggregation of Revenue [Line Items]
Revenue from contract with customer		350,000				350,000
Remaining performance obligation, variable consideration amount		$ 350,000				$ 350,000
Development and Commercialization of mRNA Therapeutics | Moderna
Disaggregation of Revenue [Line Items]
Revenue from contract with customer				$ 2,200,000			$ 2,200,000

Prepaid Expenses and Other Cu_3

Prepaid Expenses and Other Current Assets (Details) - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]
Research and development claims receivable	$ 37,111	$ 24,685
Prepayments	7,535	12,337
VAT receivable	2,327	2,701
Other receivable	2,357	1,469
Deferred cost	1,911	1,494
Other assets	127	203
Accounts receivable	165	121
Total prepaid expenses and other current assets	$ 51,533	$ 43,010

Property and Equipment, Net - S

Property and Equipment, Net - Schedule of PPE (Details) - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022
Property, Plant and Equipment
Less: accumulated depreciation	$ (29,017)	$ (27,542)
Total property and equipment, net	34,637	35,209
Lab equipment
Property, Plant and Equipment
Property and equipment, gross	26,362	31,188
Office equipment
Property, Plant and Equipment
Property and equipment, gross	4,416	3,573
Furniture and fixtures
Property, Plant and Equipment
Property and equipment, gross	1,982	1,221
Leasehold improvements
Property, Plant and Equipment
Property and equipment, gross	12,655	13,583
Assets under construction
Property, Plant and Equipment
Property and equipment, gross	$ 18,239	$ 13,186

Property and Equipment, Net - N

Property and Equipment, Net - Narratives (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Property, Plant and Equipment [Abstract]
Depreciation expense	$ 1.4	$ 1.8	$ 4.8	$ 5.7

Accrued Expenses and Other Li_3

Accrued Expenses and Other Liabilities (Details) - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022
Payables and Accruals [Abstract]
Research and development costs	$ 17,863	$ 26,478
Compensation and benefits	10,169	10,181
Professional fees	2,873	3,745
Other liabilities	483	393
Total accrued expenses and other liabilities	$ 31,388	$ 40,797

Shareholders_ Equity - Narrativ

Shareholders’ Equity - Narrative (Details) - USD ($) $ / shares in Units, $ in Millions	1 Months Ended
	Nov. 02, 2023	Dec. 31, 2022	Sep. 30, 2023
Unvested restricted shares and units
Class of Stock
Vested not issued (in shares)			56,269
Unvested restricted shares and units | Subsequent Event
Class of Stock
Shares issued (in shares)	52,363
Ordinary shares | Underwriters public offering
Class of Stock
Number of shares issued in transaction (in shares)		81,927,012
Per share price of issuance (usd per share)		$ 2
Proceeds of issuance of ordinary shares, net of issuance costs		$ 152.4
Ordinary shares | Options
Class of Stock
Number of shares issued in transaction (in shares)		6,927,012

Share-based Compensation Expe_3

Share-based Compensation Expense - Share-based Compensation Allocation (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Share-based Compensation Arrangement by Share-based Payment Award
Total share-based compensation	$ 2,864	$ 3,337	$ 7,948	$ 8,599
Research and development
Share-based Compensation Arrangement by Share-based Payment Award
Total share-based compensation	1,525	1,831	4,982	4,802
General and administrative
Share-based Compensation Arrangement by Share-based Payment Award
Total share-based compensation	1,335	1,506	2,947	3,797
Capitalized
Share-based Compensation Arrangement by Share-based Payment Award
Total share-based compensation	$ 4	$ 0	$ 19	$ 0

Net loss per share - Schedule o

Net loss per share - Schedule of Net Loss Per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Numerator
Net loss	$ (45,849)	$ (42,767)	$ (131,212)	$ (121,888)
Net loss attributable to ordinary shareholders - basic	(45,849)	(42,767)	(131,212)	(121,888)
Net loss attributable to ordinary shareholders - diluted	$ (45,849)	$ (42,767)	$ (131,212)	$ (121,888)
Denominator
Weighted-average number of ordinary shares used in net loss per share - basic (in shares)	173,984,101	91,240,801	173,890,666	91,028,562
Weighted-average number of ordinary shares used in net loss per share - diluted (in shares)	173,984,101	91,240,801	173,890,666	91,028,562
Earnings Per Share
Net loss per share - basic (in usd per share)	$ (0.26)	$ (0.47)	$ (0.75)	$ (1.34)
Net loss per share - diluted (in usd per share)	$ (0.26)	$ (0.47)	$ (0.75)	$ (1.34)

Net loss per share - Schedule_2

Net loss per share - Schedule of Anti-dilutive Securities (Details) - shares	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Antidilutive Securities
Total potentially dilutive securities (in shares)	17,604,474	14,683,370	17,604,474	14,683,370
Unvested restricted shares and units
Antidilutive Securities
Total potentially dilutive securities (in shares)	264,326	996,927	264,326	996,927
Share options
Antidilutive Securities
Total potentially dilutive securities (in shares)	14,074,842	10,421,137	14,074,842	10,421,137
Warrants
Antidilutive Securities
Total potentially dilutive securities (in shares)	3,265,306	3,265,306	3,265,306	3,265,306

Liability related to sales of_3

Liability related to sales of future royalties and sales milestones, net - Narrative (Details) $ in Millions	1 Months Ended
	Dec. 31, 2022 USD ($) payment	Nov. 30, 2021 USD ($)	Sep. 30, 2023 USD ($)
Class of Warrant or Right [Line Items]
Number of development payments | payment	2
Contract with customer, liability			$ 140.8
Blackstone | Blackstone Collaboration Agreement
Class of Warrant or Right [Line Items]
Contract with customer, liability gross		$ 50
Contract with customer, liability	$ 35
Remaining performance obligation, variable consideration amount	$ 30
Strategic Collaboration and Financing Agreement
Class of Warrant or Right [Line Items]
Interest rate (in percent)	15.80%		15.80%

Liability related to sales of_4

Liability related to sales of future royalties and sales milestones, net - Schedule of Liability Related to Revenue (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022	Dec. 31, 2022
Liability, Future Revenue [Roll Forward]
Interest expense accrued on liability related to future royalties and sales milestones, net	$ 5,000	$ 1,800	$ 14,878	$ 5,427
Blackstone Collaboration Agreement
Liability, Future Revenue [Roll Forward]
Beginning Balance			125,900	$ 47,016	$ 47,016
Proceeds from Blackstone Development Payments received					70,000
Interest expense accrued on liability related to future royalties and sales milestones, net			14,878		8,005
Cumulative catch-up adjustment					879
Ending Balance	$ 140,778		$ 140,778		$ 125,900

Leases - Narrative (Details)

Leases - Narrative (Details) € in Thousands	1 Months Ended				9 Months Ended
	Oct. 31, 2021 USD ($) contract thirdParty unit	Aug. 31, 2021	Mar. 31, 2021 USD ($) unit	Sep. 30, 2017	Sep. 30, 2023 USD ($) manufacturingSuite	Sep. 30, 2022 USD ($)	Sep. 19, 2023	Oct. 31, 2021 EUR (€)	Sep. 30, 2021 ft²	Feb. 28, 2019 unit	Oct. 31, 2018
Lessor, Lease, Description [Line Items]
Manufacturing suite with extended lease term | manufacturingSuite					1
Gain (loss) on termination of operating lease					$ (95,000)	$ 0
Real estate units split | unit			1
Real estate units after split | unit			2
Number of contracts | contract	2
Payments for tenant improvements					7,500,000
ARO					100,000
Operating lease, number of third parties | thirdParty	2
Number of manufacturing properties | contract	2
Total lease payments receivable					1,019,000
Proceeds from deposits from customers	$ 100,000
Sublease, Lease Term 1
Lessor, Lease, Description [Line Items]
Total lease payments receivable | €								€ 97
Sublease, Lease Term 2
Lessor, Lease, Description [Line Items]
Total lease payments receivable | €								€ 109
Manufacturing Suite in Stevenage, United Kingdom
Lessor, Lease, Description [Line Items]
Gain (loss) on termination of operating lease					(100,000)
Loss of disposal on leasehold improvements					$ (3,800,000)
Operating lease contract term (in years)							20 years
Number of square feet | ft²									70,000
Manufacturing Suite in Stevenage, United Kingdom | Manufacturing Facility
Lessor, Lease, Description [Line Items]
Operating lease rent-free period (in months)				6 months
Office Space in Rockville, Maryland | Building
Lessor, Lease, Description [Line Items]
Operating lease contract term (in years)											5 years
MediaWorks Corporate Headquarters | Additional Space
Lessor, Lease, Description [Line Items]
Operating lease rent-free period (in months)		18 months
Operating lease contract term (in years)		9 years 11 months
Manufacturing Space in Enfield, United Kingdom
Lessor, Lease, Description [Line Items]
Gain (loss) on termination of operating lease			$ 100,000
Lease termination fee expense			$ 200,000
Manufacturing Space in Enfield, United Kingdom | Building
Lessor, Lease, Description [Line Items]
Operating lease contract term (in years)										15 years
Number of units | unit										3
Number of units surrendered | unit			1
Number of contracts | unit	2

Leases - Lease Cost (Details)

Leases - Lease Cost (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Leases [Abstract]
Operating lease costs	$ 2,061	$ 1,103	$ 5,235	$ 3,542
Variable costs	573	268	657	720
Short term lease costs	227	119	451	231
Total lease costs	$ 2,861	$ 1,490	6,343	4,493
Operating cash outflows from operating leases (in thousands)			$ 7,817	$ 3,740
Weighted-average remaining lease term - operating leases (in years)	15 years 10 months 24 days	5 years 1 month 6 days	15 years 10 months 24 days	5 years 1 month 6 days
Weighted-average discount rate — operating leases (percent)	7.44%	7.18%	7.44%	7.18%

Leases - Schedule of Maturity P

Leases - Schedule of Maturity Payments (Details) $ in Thousands	Sep. 30, 2023 USD ($)
Leases [Abstract]
Remainder of 2023	$ 1,975
2024	8,062
2025	6,625
2026	6,396
2027	6,255
Thereafter	60,424
Total lease payments	89,737
Less: imputed interest	(37,279)
Present value of lease liabilities	$ 52,458

Leases - Sublease Classificatio

Leases - Sublease Classification (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Leases [Abstract]
Total sublease rental income	$ 61	$ 57	$ 181	$ 183

Leases - Sublease Income Maturi

Leases - Sublease Income Maturity (Details)	Sep. 30, 2023 USD ($)
Leases [Abstract]
Remainder of 2023	$ 65,000
2024	261,000
2025	261,000
2026	203,000
2027	123,000
Thereafter	106,000
Total lease payments receivable	$ 1,019,000

Commitments and Contingencies -

Commitments and Contingencies - Narrative (Details) - USD ($)	3 Months Ended	9 Months Ended
	Sep. 30, 2023	Sep. 30, 2023	Dec. 31, 2022
Long-term Purchase Commitment [Line Items]
Payments for license fees	$ 100,000	$ 200,000
Loss contingency accrual	0	0	$ 0
Unconditional purchase obligations for capital expenditures	4,200,000	4,200,000
Miltenyi Biotech B.V. & Co. KG ("Miltenyi")
Long-term Purchase Commitment [Line Items]
Annual license fee	$ 400,000	$ 400,000

Related parties - Narrative (De

Related parties - Narrative (Details) $ / shares in Units, $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2023 USD ($)	Dec. 31, 2022 USD ($) $ / shares	Dec. 31, 2021 USD ($)	Nov. 30, 2021 contract
Related Party Transaction
Number of directors | contract				1
Contract with customer, liability	$ 140,800
Accrued interest	24,900
Blackstone Collaboration Agreement
Related Party Transaction
Carrying amount of liability	140,778	$ 125,900	$ 47,016
Non-cash interest expense, catch-up		$ 10,000
Syncona LLP | Underwriters public offering
Related Party Transaction
Exercise price of warrant (in usd per share) | $ / shares		$ 2
Investee of Syncona | License revenue
Related Party Transaction
Remaining performance obligation, variable consideration amount	$ 350
Autolus | Investee Of Syncona Portfolio Limited | License revenue
Related Party Transaction
Ownership percentage by noncontrolling owners (in percent)	10%
Blackstone | Autolus
Related Party Transaction
Ownership percentage by noncontrolling owners (in percent)				10%

Related parties - Summary of AD

Related parties - Summary of ADS Purchases (Details) $ in Millions	Sep. 30, 2023 USD ($) shares
Related Party Transaction
ADSs Purchased (in shares) | shares	56,500,000
Total purchase price | $	$ 113
Syncona LLP
Related Party Transaction
ADSs Purchased (in shares) | shares	14,000,000
Total purchase price | $	$ 28
Deep Track Capital, LP
Related Party Transaction
ADSs Purchased (in shares) | shares	15,000,000
Total purchase price | $	$ 30
Qatar Investment Authority
Related Party Transaction
ADSs Purchased (in shares) | shares	15,000,000
Total purchase price | $	$ 30
Armistice Capital, LLC
Related Party Transaction
ADSs Purchased (in shares) | shares	10,000,000
Total purchase price | $	$ 20
Blackstone
Related Party Transaction
ADSs Purchased (in shares) | shares	2,500,000
Total purchase price | $	$ 5