Summit Therapeutics (SMMT) 10-Q 7 Nov 23 2023 Q3 Quarterly report Financial data

Cover

Cover - shares	9 Months Ended
	Sep. 30, 2023	Oct. 31, 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	001-36866
Entity Registrant Name	Summit Therapeutics Inc.
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	37-1979717
Entity Address, Address Line One	2882 Sand Hill Road, Suite 106
Entity Address, City or Town	Menlo Park
Entity Address, State or Province	CA
Entity Address, Postal Zip Code	94025
City Area Code	650
Local Phone Number	460-8308
Title of 12(b) Security	Common Stock, $0.01 par value per share
Trading Symbol	SMMT
Security Exchange Name	NASDAQ
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Non-accelerated Filer
Entity Small Business	true
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		700,842,898
Entity Central Index Key	0001599298
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2023
Document Fiscal Period Focus	Q3
Amendment Flag	false

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022
Current assets:
Cash and cash equivalents	$ 23,792	$ 348,607
Restricted cash	0	300,000
Short-term investments	175,153	0
Accounts receivable	0	349
Prepaid expenses	5,074	1,504
Other current assets	120	486
Research and development tax credit receivable	812	5,766
Total current assets	204,951	656,712
Non-current assets:
Research and development tax credit receivable	747	0
Property and equipment, net	229	906
Right-of-use assets	6,403	4,175
Goodwill	1,814	1,798
Other assets	4,332	577
Total assets	218,476	664,168
Current liabilities:
Accounts payable	3,314	355
Accrued expenses	3,654	10,664
Accrued compensation	3,510	5,641
Lease liabilities	2,780	1,690
Other current liabilities	484	662
Promissory note payable to a related party	100,000	19,770
Total current liabilities	$ 113,742	$ 38,782
Notes Payable, Current, Related and Nonrelated Party Status [Extensible Enumeration]	Related Party	Related Party
Non-current liabilities:
Lease liabilities, net of current portion	$ 3,879	$ 2,763
Other non-current liabilities	1,476	1,429
Promissory note payable to a related party	0	494,540
Total liabilities	$ 119,097	$ 537,514
Notes Payable, Noncurrent, Related and Nonrelated Party Status [Extensible Enumeration]	Related Party	Related Party
Commitments and contingencies (Note 17)
Stockholders' equity:
Preferred stock, $0.01 par value, 20,000,000 shares authorized; none issued and outstanding at September 30, 2023 and December 31, 2022, respectively	0	0
Common stock, $0.01 par value: 1,000,000,000 shares authorized; 697,851,308 and 211,091,425 shares issued and outstanding at September 30, 2023 and December 31, 2022, respectively	6,978	2,110
Additional paid-in capital	1,051,415	504,767
Accumulated other comprehensive loss	(2,323)	(1,893)
Accumulated deficit	(956,691)	(378,330)
Total stockholders' equity	99,379	126,654
Total liabilities and stockholders' equity	$ 218,476	$ 664,168

Condensed Consolidated Balanc_2

Condensed Consolidated Balance Sheets (Parenthetical) - $ / shares	Sep. 30, 2023	Dec. 31, 2022
Statement of Financial Position [Abstract]
Preferred stock, par value (in dollars per share)	$ 0.01	$ 0.01
Preferred stock, shares authorized (in shares)	20,000,000	20,000,000
Preferred stock, shares issued (in shares)	0	0
Preferred stock, shares outstanding (in shares)	0	0
Common stock par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, shares authorized (in shares)	1,000,000,000	1,000,000,000
Common stock, shares issued (in shares)	697,851,308	211,091,425
Common stock, shares outstanding (in shares)	697,851,308	211,091,425

Condensed Consolidated Statemen

Condensed Consolidated Statements of Operations and Comprehensive Loss - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Income Statement [Abstract]
Revenue	$ 0	$ 220	$ 0	$ 705
Operating expenses:
Research and development	15,323	17,049	34,657	46,613
In-process research and development	0	0	520,915	0
General and administrative	5,434	5,573	18,690	19,165
Total operating expenses	20,757	22,622	574,262	65,778
Other operating income, net	265	5,462	822	13,283
Operating loss	(20,492)	(16,940)	(573,440)	(51,790)
Other (expense) income, net	(776)	(4,445)	(4,921)	(7,763)
Net loss	$ (21,268)	$ (21,385)	$ (578,361)	$ (59,553)
Net loss per share:
Basic (in dollars per share)	$ (0.03)	$ (0.10)	$ (0.98)	$ (0.37)
Diluted (in dollars per share)	$ (0.03)	$ (0.10)	$ (0.98)	$ (0.37)
Weighted-average shares used to compute net loss per share:
Basic (in shares)	697,739,477	208,909,351	592,366,880	161,846,345
Diluted (in shares)	697,739,477	208,909,351	592,366,880	161,846,345
Comprehensive loss:
Net loss	$ (21,268)	$ (21,385)	$ (578,361)	$ (59,553)
Other comprehensive (loss) income:
Foreign currency translation adjustments	108	(49)	(20)	(1,020)
Reclassification of cumulative currency translation gain to other (expense) income, net	0	0	(419)	0
Net changes related to short-term investments	6	0	9	0
Comprehensive loss	$ (21,154)	$ (21,434)	$ (578,791)	$ (60,573)

Condensed Consolidated Statem_2

Condensed 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		98,039,540
Beginning balance at Dec. 31, 2021	$ 83,284	$ 980	$ 384,049	$ (2,197)	$ (299,548)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Rights offering of common stock, net of offering costs (in shares)		103,092,783
Rights offering of common stock, net of offering costs	99,889	$ 1,031	98,858
Issuance of common stock under stock purchase plans and exercise of stock options (in shares)		188,852
Issuance of common stock under stock purchase plans and exercise of stock options	295	$ 2	293
Stock-based compensation	9,290		9,290
Imputed interest on promissory note payable to a related party	1,063		1,063
Net changes related to short-term investments	0
Reclassification of cumulative translation gain (Note 8)	0
Foreign currency translation adjustments	(1,020)			(1,020)
Net loss	(59,553)				(59,553)
Ending balance (in shares) at Sep. 30, 2022		201,321,175
Ending balance at Sep. 30, 2022	133,248	$ 2,013	493,553	(3,217)	(359,101)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Offering costs	111
Beginning balance (in shares) at Jun. 30, 2022		98,122,356
Beginning balance at Jun. 30, 2022	51,317	$ 981	391,220	(3,168)	(337,716)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Rights offering of common stock, net of offering costs (in shares)		103,092,783
Rights offering of common stock, net of offering costs	99,889	$ 1,031	98,858
Issuance of common stock under stock purchase plans and exercise of stock options (in shares)		106,036
Issuance of common stock under stock purchase plans and exercise of stock options	108	$ 1	107
Stock-based compensation	2,798		2,798
Imputed interest on promissory note payable to a related party	570		570
Net changes related to short-term investments	0
Reclassification of cumulative translation gain (Note 8)	0
Foreign currency translation adjustments	(49)			(49)
Net loss	(21,385)				(21,385)
Ending balance (in shares) at Sep. 30, 2022		201,321,175
Ending balance at Sep. 30, 2022	133,248	$ 2,013	493,553	(3,217)	(359,101)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Offering costs	$ 111
Beginning balance (in shares) at Dec. 31, 2022	211,091,425	211,091,425
Beginning balance at Dec. 31, 2022	$ 126,654	$ 2,110	504,767	(1,893)	(378,330)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Rights offering of common stock, net of offering costs (in shares)		476,190,471
Rights offering of common stock, net of offering costs	499,381	$ 4,762	494,619
Issuance of common stock under stock purchase plans and exercise of stock options (in shares)		569,412
Issuance of common stock under stock purchase plans and exercise of stock options	880	$ 6	874
Issuance of common stock in lieu of cash for Akeso upfront payment (in shares)		10,000,000
Issuance of common stock in lieu of cash for Akeso upfront payment	45,900	$ 100	45,800
Stock-based compensation	5,355		5,355
Net changes related to short-term investments	9			9
Reclassification of cumulative translation gain (Note 8)	(419)			(419)
Foreign currency translation adjustments	(20)			(20)
Net loss	$ (578,361)				(578,361)
Ending balance (in shares) at Sep. 30, 2023	697,851,308	697,851,308
Ending balance at Sep. 30, 2023	$ 99,379	$ 6,978	1,051,415	(2,323)	(956,691)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Offering costs	619
Beginning balance (in shares) at Jun. 30, 2023		697,685,365
Beginning balance at Jun. 30, 2023	119,599	$ 6,976	1,050,483	(2,437)	(935,423)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock under stock purchase plans and exercise of stock options (in shares)		165,943
Issuance of common stock under stock purchase plans and exercise of stock options	229	$ 2	227
Stock-based compensation	705		705
Net changes related to short-term investments	6			6
Reclassification of cumulative translation gain (Note 8)	0
Foreign currency translation adjustments	108			108
Net loss	$ (21,268)				(21,268)
Ending balance (in shares) at Sep. 30, 2023	697,851,308	697,851,308
Ending balance at Sep. 30, 2023	$ 99,379	$ 6,978	$ 1,051,415	$ (2,323)	$ (956,691)

Condensed Consolidated Statem_3

Condensed Consolidated Statements of Stockholders' Equity (Parenthetical) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Statement of Stockholders' Equity [Abstract]
Offering costs	$ 111	$ 619	$ 111

Condensed Consolidated Statem_4

Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022
Cash flows used in operating activities:
Net loss	$ (578,361)	$ (59,553)
Adjustments to reconcile net loss to net cash used in operating activities:
Non-cash interest expense	6,171	853
Amortization of discount on short-term investments	(1,716)	0
Unrealized foreign exchange loss (gain)	(370)	4,271
Reclassification of currency translation gain	(419)	0
Impairment of fixed assets	474	0
Amortization of operating right-of-use assets	1,277	960
Depreciation	168	261
Amortization of intangible assets	0	697
Gain on disposal of assets	(111)	0
Stock-based compensation	5,355	9,290
In-process research and development	520,915	0
Change in operating assets and liabilities:
Accounts receivable	359	2,387
Prepaid expenses	(3,554)	5,006
Other current and long-term assets	(3,378)	558
Research and development tax credit receivable	4,346	(3,675)
Deferred revenue and other income	0	(7,554)
Accounts payable	2,935	(1,763)
Accrued liabilities	(7,728)	4,817
Accrued compensation	(2,145)	(2,437)
Operating lease liabilities	(1,519)	(891)
Net cash used in operating activities	(57,301)	(46,773)
Cash flows used in investing activities:
Purchases of property and equipment	(126)	(634)
Proceeds from sale of property. plant and equipment	226	0
Purchase of short-term investments	(321,023)	0
Maturities and sales of short-term investments	147,596	0
Payments to Akeso for upfront milestone payments and associated direct transaction costs	(475,015)	0
Net cash used in investing activities	(648,342)	(634)
Cash flows provided by financing activities:
Proceeds from the issuance of common stock for rights offering	104,686	100,000
Transaction costs related to the issuance of common stock for rights offering	(619)	(111)
Proceeds from related party promissory notes	0	25,000
Repayment of related party promissory notes	(24,686)	(25,000)
Proceeds received related to employee stock awards	880	295
Net cash provided by financing activities	80,261	100,184
Effect of exchange rate changes on cash	567	(2,597)
(Decrease) increase in cash and cash equivalents	(624,815)	50,180
Cash at beginning of the period	648,607	71,791
Cash and cash equivalents at end of the period	23,792	121,971
Supplemental Disclosure of Cash Flow Information:
Cash paid for interest on related party promissory notes	7,711	434
Cash paid for income taxes	52	0
Lease assets obtained in exchange for operating lease liabilities	4,245	2,756
Rights offering
Issuance of common stock	395,314	0
Akeso License Agreement
Issuance of common stock	$ 45,900	$ 0

Nature of Business and Operatio

Nature of Business and Operations and Recent Events	9 Months Ended
	Sep. 30, 2023
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Nature of Business and Operations and Recent Events	Nature of Business and Operations and Recent Events Nature of Business and Operations Summit Therapeutics Inc. ("we", "Summit" or the "Company") is a biopharmaceutical company focused on the discovery, development, and commercialization of patient-, physician-, caregiver- and societal-friendly medicinal therapies intended to improve quality of life, increase potential duration of life, and resolve serious unmet medical needs. The Company's pipeline of product candidates is designed with the goal to become the patient-friendly, new-era standard-of-care medicines, in the therapeutic area of oncology. The Company recently in-licensed from Akeso, Inc. ("Akeso") its breakthrough bispecific antibody, ivonescimab. Ivonescimab, known as AK112 in China and Australia, and also as SMT112 in the United States, Canada, Europe, and Japan, is a novel, potential first-in-class bispecific antibody intending to combine the benefits of immunotherapy via a blockade of PD-1 with the anti-angiogenesis benefits of an anti-VEGF into a single molecule. Ivonescimab was engineered to bring two well-established oncology targeted mechanisms together. Through the License Agreement (as defined below), Summit obtained the rights to develop and commercialize SMT112 in the United States, Canada, Europe, and Japan (the "Licensed Territory"). The entry into the License Agreement represents a significant change in the Company’s strategy. All business activities related to anti-infectives are being reviewed for partnership opportunities for potential further development. The Company's future operations will be focused on the development of ivonescimab and other future activities, as the Company determines. The Company has begun its development for ivonescimab in non-small cell lung cancer ("NSCLC"), specifically launching Phase III clinical trials in the following indications: a) ivonescimab combined with chemotherapy in patients with epidermal growth factor receptor ("EGFR")-mutated, locally advanced or metastatic non-squamous NSCLC who have progressed after treatment with a third-generation EGFR tyrosine kinase inhibitor ("TKI") (“HARMONi”); and b) ivonescimab combined with chemotherapy in first-line metastatic squamous NSCLC patients (“HARMONi-3”) The Company has been treating patients in the HARMONi clinical trial and has recently commenced enrollment in its second Phase III HARMONi-3 clinical trial. Recent Events On December 5, 2022, the Company entered into a Collaboration and License Agreement (the “License Agreement”) with Akeso, Inc. and its affiliates (“Akeso”) pursuant to which the Company is in-licensing breakthrough bispecific antibody, ivonescimab. Ivonescimab, is a novel, potential first-in-class bispecific antibody intending to combine the effects of immunotherapy via a blockade of PD-1 with the anti-angiogenesis effects of an anti-VEGF compound into a single molecule. Through the License Agreement, the Company obtained the rights to develop and commercialize ivonescimab in the United States, Canada, Europe, and Japan (the “Licensed Territory”). The License Agreement and transaction closed in January 2023 following customary waiting periods. See Note 8 for further information. On December 6, 2022, the Company announced a rights offering for its existing shareholders to participate in the purchase of additional shares of its common stock (the "2023 Rights Offering"). The 2023 Rights Offering commenced on February 7, 2023 and the associated subscription rights expired on March 1, 2023. Aggregate gross proceeds from the Rights Offering were $500,000 from the sale of 476,190,471 shares of the Company's common stock at a price of $1.05 per share, net of issuance costs of $619. On December 6, 2022, the Company entered into a Note Purchase Agreement (the "Note Purchase Agreement", further defined in Note 14), with its Co-CEOs, Mr. Robert W. Duggan and Dr. Mahkam Zanganeh, pursuant to which the Company agreed to sell to each of Mr. Duggan and Dr. Zanganeh unsecured promissory notes in the aggregate amount of $520,000. On January 19, 2023, the Company filed Amendment No. 2 to the Restated Certificate of Incorporation (the “Amendment No. 2”) with the Secretary of State of the State of Delaware to increase the number of authorized shares of its common stock by 650,000,000 (from 350,000,000 to 1,000,000,000), which became effective on such date. On February 15, 2023, the $20,000 Zanganeh Note, as defined in Note 14, matured and the Company repaid the outstanding principal balance. In connection with the closing of the 2023 Rights Offering, the $400,000 Duggan Promissory Note, as defined in Note 14, matured and became due, and the Company satisfied all principal and accrued interest thereunder using a combination of a portion of the cash proceeds from the 2023 Rights Offering and the extinguishment of a portion of the amount due equal to the subscription price for shares subscribed by Mr. Duggan in the 2023 Rights Offering. On March 17, 2023, the Company filed a registration statement on Form S-3 to register for resale the following shares of the Company's common stock at $0.01 par value: (i) 10,000,000 shares of Common Stock issued on January 17, 2023 in connection with the License Agreement with Akeso pursuant to which the Company issued Akeso such shares; and (ii) the 9,346,434 and 373,857 shares of Common Stock issued in December 2022 to the Company's Co-CEOs, Mr. Duggan and Dr. Mahkam Zanganeh, respectively, as payment of prepaid interest in connection with the Note Purchase Agreement dated December 6, 2022 between Mr. Duggan, Dr. Mahkam Zanganeh and the Company. On April 27, 2023, the SEC issued the Company a Notice of Effectiveness for the registration statement on Form S-3 filed with the SEC. On October 12, 2023, the Company held a Special Meeting of Stockholders (the "October Special Meeting") whereby an amendment to the Summit Therapeutics Inc. 2020 Stock Incentive Plan (the "Plan") to increase the number of shares of the Company's common stock issuable under the Plan by 70,000,000 shares was approved by a vote of the Company's stockholders at the Special Meeting and subsequently ratified by the Board of Directors. On October 16, 2023, the Company announced the appointment of Mr. Manmeet Soni as its Chief Operating Officer, effective immediately. Mr. Soni has been a part of the Company's Board of Directors since 2019. He will remain a member of the Board of Directors. In conjunction with his appointment, Mr. Soni entered into a share purchase agreement with the Company to purchase $5,000 of its common stock via a private placement. The transaction was effective October 13, 2023 with a closing price of $1.68, resulting in the purchase of 2,976,190 shares of the Company's common stock.

Basis of Presentation, Use of E

Basis of Presentation, Use of Estimates, and Risks and Uncertainties	9 Months Ended
	Sep. 30, 2023
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Basis of Presentation, Use of Estimates, and Risks and Uncertainties	Basis of Presentation, Use of Estimates, and Risks and Uncertainties Basis of Presentation The accompanying unaudited condensed consolidated financial statements have been prepared in accordance with accounting principles generally accepted in the United States ("U.S. GAAP") and pursuant to the rules and regulations of the U.S. Securities and Exchange Commission. Accordingly, certain information and disclosures required by U.S. GAAP for complete consolidated financial statements are not included herein. All intercompany accounts and transactions have been eliminated in consolidation. The interim financial data as of September 30, 2023 and for the three and nine months ended September 30, 2023 are unaudited; however, in the opinion of management, the interim data includes all adjustments, consisting of normal recurring adjustments, necessary for a fair statement of the results for the interim periods. The condensed consolidated balance sheet presented as of December 31, 2022 has been derived from the consolidated audited financial statement as of that date. The results of the period are not necessarily indicative of full year results or any other interim period. These unaudited interim condensed consolidated financial statements should be read in conjunction with the audited financial statements and notes thereto of the Company which are included in the Summit Annual Report on Form 10-K for the year ended December 31, 2022 filed with the Securities and Exchange Commission on March 9, 2023. The financial results of the Company's activities are reported in United States Dollars. Our accounting policies are consistent with the Notes to Consolidated Financial Statements in our 2022 Form 10-K, except as updated below: Cash equivalents During the nine months ended September 30, 2023, cash consisted of non-interest-bearing deposits denominated in the U.S. dollar and British pound, and the Company invested cash in money market funds and U.S. treasury securities. All highly liquid investments with a maturity date of 90 days or less at the date of purchase are considered to be cash equivalents. The appropriate classification of investments in securities as to whether it is classified as a cash equivalent is determined by the Company at the time of purchase. Marketable securities Marketable securities consist of investments with original maturities greater than ninety days from the date of acquisition. The Company classifies investments with maturities of greater than 90 days as short-term, based on the liquid nature of the securities and because such marketable securities represent the investment of cash that is available for current operations. The Company considers its investment portfolio of investments as available-for-sale. Accordingly, these investments are recorded at fair value, which is based on quoted market prices or other observable inputs. Unrealized gains and losses are recorded as a component of other comprehensive income (loss). Realized gains and losses are determined on a specific identification basis and are included in other (expense) income. Amortization and accretion of discounts and premiums is also recorded in other (expense) income. When the fair value is below the amortized cost of the asset, an estimate of expected credit losses is made, this estimate is limited to the amount by which fair value is less than amortized cost. The credit-related impairment amount is recognized in the condensed consolidated statements of operations and comprehensive loss and the remaining impairment amount and unrealized gains are reported as a component of accumulated other comprehensive income (loss) in shareholders’ equity. Credit losses are recognized through the use of an allowance for credit losses account and subsequent improvements in expected credit losses are recognized as a reversal of the allowance account. If the Company has the intent to sell the security or it is more likely than not that the Company will be required to sell the security prior to recovery of its amortized cost basis the allowance for credit loss is written off and the excess of the amortized cost basis of the asset over its fair value is recorded in the condensed consolidated statements of operations and comprehensive loss. Use of Estimates The preparation of these unaudited condensed consolidated financial statements requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and the disclosure of contingent liabilities at the date of the unaudited condensed consolidated financial statements and the reported amounts of revenues and expenses during the reporting period. On an on-going basis, management evaluates its estimates and judgments, including those related to revenue recognition, accrued research and development expenses, stock-based compensation, intangible assets, goodwill, other long-lived assets and income taxes. Management bases its estimates and judgments on historical experience and on various other factors that are believed to be reasonable under the circumstances, the results of which form the basis for making judgments about the carrying values of assets and liabilities that are not readily apparent from other sources. Actual results may differ from these estimates under different assumptions or conditions. Risks and Uncertainties While the impact of COVID-19 decreased during the Company’s fiscal 2022 year and the first, second and third quarters of its fiscal 2023 year, outbreaks of COVID-19 or its variants, either locally, nationally or globally, as well as related supply chain issues, could adversely impact the Company’s business.

Recently Issued or Adopted Acco

Recently Issued or Adopted Accounting Pronouncements	9 Months Ended
	Sep. 30, 2023
Accounting Changes and Error Corrections [Abstract]
Recently Issued or Adopted Accounting Pronouncements	Recently Issued or Adopted Accounting Pronouncements In June 2016, the FASB issued ASU 2016-13, "Financial Instruments - Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments", which has subsequently been amended by ASU 2019-04 and ASU 2019-10 (collectively "ASU 2016-03"). ASU 2016-13 amends the guidance on the impairment of financial instruments. This update adds an impairment model (known as the current expected credit losses model) that is based on expected losses rather than incurred losses. Under the new guidance, an entity recognizes, as an allowance, its estimate of expected credit losses. The Company adopted this standard on January 1, 2023, and it did not have a material impact on the condensed consolidated financial statements or related disclosures. In May 2021, the FASB issued ASU No. 2021-04, "Earnings Per Share (Topic 260), Debt - Modifications and Extinguishments (Subtopic 470-50), Compensation - Stock Compensation (Topic 718), and Derivatives and Hedging Contracts in Entity's Own Equity (Subtopic 815-40) - Issuer's Accounting for Certain Modifications or Exchanges of Freestanding Equity-Classified Written Call Options". This ASU provides clarification and reduces diversity in an issuer’s accounting for modifications or exchanges of freestanding equity-classified written call options (such as warrants) that remain equity classified after modification or exchange. This ASU is effective for annual periods, and interim periods within those fiscal years, beginning after December 15, 2021. The Company will apply this ASU on a prospective basis for any modifications or exchanges once this ASU is effective and at that time, will be able to determine the potential impact on its financial position, results of operations or cash flows. There have been no modifications or exchanges relating to this ASU during 2023 or 2022. Other recent authoritative guidance issued by the FASB (including technical corrections to the FASB ASC), the American Institute of Certified Public Accountants, and the SEC did not or are not expected to have a material impact on the Company's condensed consolidated financial statements.

Liquidity and Capital Resources

Liquidity and Capital Resources	9 Months Ended
	Sep. 30, 2023
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Liquidity and Capital Resources	Liquidity and Capital Resources During the three and nine months ended September 30, 2023, the Company incurred a net loss of $21,268 and $578,361, and cash flows used in operating activities for the nine months ended September 30, 2023 was $57,301. As of September 30, 2023, the Company had an accumulated deficit of $956,691, cash and cash equivalents of $23,792, short-term investments in U.S. treasury securities of $175,153 and current and long-term U.K. research and development tax credits receivable of $1,559. The Company expects to continue to generate operating losses for the foreseeable future. The Company has evaluated whether its cash, cash equivalents and U.K. research and development tax credits provide sufficient cash to fund its operating cash needs for the next twelve months from the date of issuance of these quarterly financials. The Company is investing in the clinical development of ivonescimab, including its ongoing clinical trials. In addition, the Company has a $100 million promissory note payable to a related party (refer to Note 14 for further details) that matures on September 6, 2024. In order to repay this promissory note, the Company intends to raise additional capital. As of the date of issuance of these condensed consolidated financial statements, additional capital has not yet been secured. These conditions raise substantial doubt about the Company’s ability to continue as a going concern for at least one year from the date these condensed consolidated financial statements are issued. Until the Company can generate substantial revenue and achieve profitability, the Company will need to raise additional capital to fund its ongoing operations and capital needs. The Company continues to evaluate options to further finance its operating cash needs for its product candidates through a combination of some, or all, of the following: equity and debt offerings, collaborations, strategic alliances, grants and clinical trial support from government entities, philanthropic, non-government and not-for-profit organizations, and marketing, distribution or licensing arrangements. There is no assurance, however, that additional financing will be available when needed or that management of the Company will be able to obtain financing on terms acceptable to the Company. If the Company is unable to obtain funding when required in the future, the Company could be required to delay, reduce, or eliminate research and development programs, product portfolio expansion, or future commercialization efforts, which could adversely affect its business prospects. The accompanying condensed consolidated financial statements are prepared assuming the Company will continue as a going concern, which contemplates the realization of assets and satisfaction of liabilities in the normal course of the business. The condensed consolidated financial statements do not include any adjustments relating to the recoverability and classification of recorded asset amounts or the amounts and classifications of liabilities that might result from the outcome of this uncertainty.

Segment Reporting

Segment Reporting	9 Months Ended
	Sep. 30, 2023
Segment Reporting [Abstract]
Segment Reporting	Segment Reporting The Company's chief operating decision makers (the "CODM function"), which are the Company's Co-CEOs, Mr. Duggan and Dr. Zanganeh, utilize consolidated financial information to make decisions about allocating resources and assessing performance for the entire Company. The CODM function approves of key operating and strategic decisions, including key decisions in clinical development and clinical operating activities, entering into significant contracts, such as revenue contracts and collaboration agreements and approves the Company's consolidated operating budget. The CODM function views the Company's operations and manages its business as a single reportable operating segment. The Company's single operating segment covers the Company’s research and development activities, primarily comprising of oncology product research activities (including ivonescimab). As the Company operates in one operating segment, all required financial segment information can be found in these condensed consolidated financial statements. The Company operates in two geographic regions: the U.K. and the U.S. The following table summarizes the Company's long-lived assets, which include the Company's property and equipment, net and right-of-use assets by geography: September 30, 2023 December 31, 2022 United Kingdom $ 832 $ 2,517 United States 5,800 2,564 $ 6,632 $ 5,081 For details of revenue from external customers by geography refer to Note 6.

Revenue

Revenue	9 Months Ended
	Sep. 30, 2023
Revenue from Contract with Customer [Abstract]
Revenue	Revenue The following table summarizes revenue by category: Three Months Ended Nine Months Ended Revenue by category: 2023 2022 2023 2022 Licensing agreements $ — $ 220 $ — $ 705 Revenue recognized for the three and nine months ended September 30, 2022 consists only of amounts received from the Company's license and commercialization agreement with Eurofarma Laboratórios S.A. No revenue has been recognized in the fiscal year 2023. The following table summarizes revenue by geography: Three Months Ended Nine Months Ended Revenue by geography: 2023 2022 2023 2022 Latin America $ — $ 220 $ — $ 705 The analysis of revenue by geography has been identified on the basis of the customer’s geographical location. The following table summarizes the deferred revenue relating to the Company's license and commercialization agreement with Eurofarma Laboratórios S.A. and deferred other income relating to BARDA (as defined in Note 7): 2023 2022 Beginning deferred revenue and other income, January 1 (1) $ — $ 7,939 Additions — 956 Amount of deferred revenue and other income recognized in the statement of operations — (8,479) Foreign currency adjustments — (416) Ending deferred revenue and other income, September 30 (2) $ — $ — ____________ (1) Beginning deferred revenue and other income as of January 1, 2023 and 2022 included $0 of current and $0 of long-term deferred revenue and other income, and $7,939 of current and $0 of long-term deferred revenue and other income, respectively. (2) Ending deferred revenue and other income as of September 30, 2023 and 2022 included $0 of current and $0 of long-term deferred revenue and other income, and $0 of current and $0 of long-term deferred revenue and other income, respectively. Refer to Note 7 below for further details regarding other income recognized under the BARDA contract.

Other Operating Income, Net

Other Operating Income, Net	9 Months Ended
	Sep. 30, 2023
Other Income and Expenses [Abstract]
Other Operating Income, Net	Other Operating Income, net The following table sets forth the components of other operating income by category: Three Months Ended Nine Months Ended Other operating (expense) income, net by category: 2023 2022 2023 2022 Funding income from BARDA (as defined below) $ — $ 3,889 $ — $ 7,774 Research and development tax credits 265 1,224 768 3,730 Grant income from CARB-X (as defined below) — 349 45 1,779 Other income — — 9 — $ 265 $ 5,462 $ 822 $ 13,283 BARDA (as defined below) In September 2017, the Company was awarded a funding contract from the Biomedical Advanced Research and Development Authority ("BARDA"), part of the Office of the Assistant Secretary for Preparedness and Response at the United States Department of Health and Human Services, in support of the Company's Ri-CoDIFy clinical trials and clinical development of ridinilazole. The awarded contract was originally worth up to $62,000. In June 2019 and again in January 2020, BARDA increased the value of the contract such that it was worth up to $72,500 and brought the total amount of committed funding to $62,400. The contract ran through April 2022 and was extended through December 2022 as a no cost contract, solely to close out open activities. As of December 31, 2022, based on translation of historical foreign currency amounts in the period of recognition, the Company had recognized $59,203 of cumulative income since contract inception. As a result of the Company's decision on September 28, 2022 to not pursue further internal clinical development of ridinilazole and seek partners or a divestiture related to ridinilazole as a path forward for the clinical development of the asset, the Company recorded expenses for the remaining clinical trial costs associated with the close out activities of ridinilazole and recognized the remainder of the deferred income that had been received from BARDA prior to the expenses being recognized during the third quarter of 2022. Research and development tax credits Income from tax credits, consist of R&D tax credits received in the U.K. The Company benefits from the Small and Medium Enterprise Program ("SME Program") U.K. research and development tax credit cash rebate regime. Qualifying expenditures largely comprise of employment costs for research staff, consumables, a proportion of relevant, permitted sub-contract costs and certain internal overhead costs incurred as part of research projects for which the Company does not receive income. Tax credits related to the SME Program are recorded as other operating income in the consolidated statements of operations and other comprehensive loss. Under this scheme, the Company receives cash payments that are not dependent on the Company’s pre-tax net income levels. Based on criteria established by His Majesty’s Revenue and Customs ("HMRC"), a portion of expenditures being carried out in relation to the Company's pipeline research and development, clinical trials management and third-party manufacturing development activities are eligible for the SME regime and the Company expects such elements of research and development expenditure incurred in its UK entities will also continue to be eligible for the SME regime for future periods. As of September 30, 2023, the current and non-current research and development tax credit receivable was $812 and $747, respectively. As of December 31, 2022, the current and non-current research and development tax credit receivable was $5,766 and $0, respectively. CARB-X (as defined below) In May 2021, the Company announced the selection of a new preclinical candidate, SMT-738, from the DDS-04 series for development in the fight against multi-drug resistant infections, specifically Carbapenem-resistant Enterobacteriaceae ("CRE") infections. Simultaneously, the Company announced it had received an award from the Trustees of Boston University under the Combating Antibiotic Resistant Bacteria Biopharmaceutical Accelerator program ("CARB-X") to progress this candidate through preclinical development and Phase Ia clinical trials. The award commits initial funding of up to $4,100, with the possibility of up to another $3,700 based on the achievement of future milestones. As of September 30, 2023, based on translation of historical foreign currency amounts in the period, the Company has recognized $2,920 of cumulative income since contract inception. During the quarter ended September 30, 2022, CARB-X announced changes to its funding arrangements and terms and conditions, and as a result, the current arrangement concluded as of June 30, 2022.

Akeso Collaboration and License

Akeso Collaboration and License Agreement	9 Months Ended
	Sep. 30, 2023
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Akeso Collaboration and License Agreement	Akeso Collaboration and License Agreement On December 5, 2022, the Company entered into a Collaboration and License Agreement (the “License Agreement”) with Akeso, Inc. and its affiliates (“Akeso”) pursuant to which the Company is in-licensing its breakthrough bispecific antibody, ivonescimab. The License Agreement and transaction closed in January 2023 following customary waiting periods. Ivonescimab, known as AK112 in China and Australia, and also as SMT112 in the United States, Canada, Europe, and Japan, is a novel, potential first-in-class bispecific antibody intending to combine the benefits of immunotherapy via a blockade of PD-1 with the anti-angiogenesis benefits of an anti-VEGF into a single molecule. Ivonescimab was engineered to bring two well established oncology targeted mechanisms together. Ivonescimab is currently in clinical development and, pursuant to the terms of the License Agreement, Summit will design and conduct the clinical trial activities to support regulatory filings in the Licensed Territory that Summit will submit. Pursuant to the terms of the License Agreement, Summit will have final decision making authority with respect to commercial strategy, pricing and reimbursement and other commercialization matters in the Licensed Territory. In connection with the License Agreement, the Company has also entered into a Supply Agreement with Akeso, pursuant to which Summit agrees to purchase a certain portion of drug substance for clinical and commercial supply. Summit is not assuming any liabilities (including contingent liabilities), acquiring any physical assets or trade names, or hiring or acquiring any employees from Akeso in connection with the License Agreement. Through the License Agreement, the Company obtained the rights to develop and commercialize SMT112 in the United States, Canada, Europe, and Japan (the “Licensed Territory”). In exchange for the rights obtained, an upfront payment of $500,000 was made to Akeso, of which $274,900 was paid in cash and, pursuant to the License Agreement and Issuance Agreement, Akeso elected to receive 10 million shares of our common stock in lieu of $25,100 cash. The remaining $200,000 amount of the upfront payment was paid on March 6, 2023. The Company has accounted for the License Agreement to acquire the rights to develop and commercialize SMT112 as the acquisition of an asset. All of the consideration relates to SMT112 and technological feasibility of the asset has not yet been established since SMT112 is in clinical development. As such, the Company has expensed the consideration as in-process research and development upon closing of the transaction in the condensed consolidated statement of comprehensive loss. In-process research and development expense for the nine months ended September 30, 2023 was $520,915, which is comprised of the $474,900 paid in cash, the fair value of the 10 million shares of common stock on the date of closing the transaction of $45,900, and $115 of direct transactions costs incurred.

Other (Expense) Income, Net

Other (Expense) Income, Net	9 Months Ended
	Sep. 30, 2023
Other Income and Expenses [Abstract]
Other (Expense) Income, Net	Other (Expense) Income, net The following table sets forth the components of other (expense) income: Three Months Ended September 30, Nine Months Ended 2023 2022 2023 2022 Foreign currency gains (losses) $ (475) $ (3,799) $ 344 $ (6,281) Interest expense on promissory notes payable to related parties (2,722) (692) (13,564) (1,497) Interest income 2,485 — 8,028 — Reclassification of cumulative currency translation gain (1) — — 419 — Other expense (64) 46 (148) 15 $ (776) $ (4,445) $ (4,921) $ (7,763) For the three months ended September 30, 2023, other income, net primarily consisted of loan interest expense incurred related to the $100,000 promissory note and unfavorable changes in foreign currency, and for the nine months ended September 30, 2023, other expense, net primarily consisted of loan interest expense incurred related to the $520,000 promissory notes, as described in Note 14, and favorable changes in foreign currency. These amounts are partially offset in both the three and nine months ended September 30, 2023 by interest income related to the Company's money market funds and the Company's short-term investments in U.S. treasury securities. (1) Effective January 17, 2023, the Company dissolved the following dormant entities; Summit (Cambridge) Limited, Summit (Wales) Limited, Summit Corporation Employee Benefit Trust Company Limited, Summit Corporation Limited, Summit Discovery 1 Limited and Summit Infectious Diseases Limited. As a result, the Company reclassified $419 of cumulative foreign currency translation adjustments from accumulated other comprehensive loss relating to these entities.

Loss per Share

Loss per Share	9 Months Ended
	Sep. 30, 2023
Earnings Per Share [Abstract]
Loss per Share	Loss per Share The following table sets forth the computation of basic and diluted net loss per share: Three Months Ended Nine Months Ended 2023 2022 2023 2022 Net loss $ (21,268) $ (21,385) $ (578,361) $ (59,553) Basic weighted average number of shares of common stock outstanding 697,739,477 208,909,351 592,366,880 161,846,345 Diluted weighted average number of shares of common stock outstanding 697,739,477 208,909,351 592,366,880 161,846,345 Basic net loss per share $ (0.03) $ (0.10) $ (0.98) $ (0.37) Diluted net loss per share $ (0.03) $ (0.10) $ (0.98) $ (0.37) Basic net loss per share is computed by dividing the net loss by the weighted-average number of common shares outstanding for the period. Diluted net loss per share is computed by dividing the diluted net loss by the weighted-average number of common shares outstanding for the period, including potentially dilutive common shares. Since the Company was in a loss position for all periods presented, basic net loss per share is the same as diluted net loss per share for all periods, as the inclusion of all potential common share equivalents outstanding would have been anti-dilutive. The 2023 Rights Offering exercise price of $1.05 per share was less than the closing price of $1.82 per share on March 1, 2023, the expiration of the 2023 Rights Offering. As such, the Company has retroactively adjusted earnings per share and weighted average number of shares outstanding for the bonus elements for all periods presented. The following potentially dilutive securities were excluded from the computation of the diluted net loss per share of common stock for the periods presented because their effect would have been anti-dilutive: September 30, 2023 2022 Options to purchase common stock 20,548,267 19,318,301 Warrants 5,821,137 5,821,137 Shares expected to be purchased under employee stock purchase plan 247,357 248,375 26,616,761 25,387,813

Fair Value Measurements and Inv

Fair Value Measurements and Investments	9 Months Ended
	Sep. 30, 2023
Fair Value Disclosures [Abstract]
Fair Value Measurements and Investments	Fair Value Measurements and Investments In accordance with the provisions of fair value accounting, a fair value measurement assumes that the transaction to sell an asset or transfer a liability occurs in the principal market for the asset or liability or, in the absence of a principal market, the most advantageous market for the asset or liability and defines fair value based upon an exit price model. The fair value measurement guidance establishes a fair value hierarchy which requires an entity to maximize the use of observable inputs and minimize the use of unobservable inputs when measuring fair value. The guidance describes three levels of inputs that may be used to measure fair value: Level 1 Quoted prices in active markets for identical assets or liabilities as of the reporting date. Active markets are those in which transactions for the asset occur in sufficient frequency and volume to provide pricing information on an ongoing basis. Level 2 Observable inputs other than Level 1 prices, such as quoted prices for similar assets or liabilities; quoted prices in markets that are not active; or other inputs that are observable or can be corroborated by observable market data for substantially the full term of the assets or liabilities. Level 3 Unobservable inputs that are supported by little or no market activity and that are significant to the fair value of the assets or liabilities. Level 3 assets include financial instruments whose value is determined using pricing models, discounted cash flow methodologies, or similar techniques, as well as instruments for which the determination of fair value requires significant management judgment or estimation. In certain cases, the inputs used to measure fair value may fall into different levels of the fair value hierarchy. In such cases, the Company categorizes such assets and liabilities based on the lowest level input that is significant to the fair value measurement in its entirety. The Company's assessment of the significance of a particular input to the fair value measurement in its entirety requires judgment and considers factors specific to the asset or liability. The following tables sets forth the Company’s fair value hierarchy for its assets and liabilities that are measured at fair value on a recurring basis as of September 30, 2023 and December 31, 2022: Fair Value Measurements as of September 30, 2023 using: Level 1 Level 2 Level 3 Total Cash equivalents: Money market funds $ 4,711 $ — $ — $ 4,711 Short-term investments: U.S. Government treasury bills $ — $ 175,153 $ — $ 175,153 Total financial assets $ 4,711 $ 175,153 $ — $ 179,864 Fair Value Measurements as of December 31, 2022 using: Level 1 Level 2 Level 3 Total Cash equivalents: Money market funds $ 60,783 $ — $ — $ 60,783 U.S. Government treasury bills $ — $ 225,730 $ — $ 225,730 Total financial assets $ 60,783 $ 225,730 $ — $ 286,513 The tables above do not include cash at September 30, 2023 and December 31, 2022 of $19,081 and $62,094, respectively. The Company believes that the carrying amounts of prepaid expenses, other current assets, accounts payable, and accrued expenses approximates their fair values due to the short-term nature of those instruments. The carrying value of the Company’s promissory note approximates its fair value due to the recent issuance of the notes in December 2022 and the current interest rate of the note outstanding when compared to market interest rates (which represents a Level 2 measurement). Refer to Note 14 for further details. The following table summarizes the Company’s investments as of September 30, 2023: September 30, 2023 Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Credit Loss Fair Value Assets U.S. Government treasury bills $ 175,144 $ 9 $ — $ — $ 175,153 Total $ 175,144 $ 9 $ — $ — $ 175,153 The following table summarizes the Company’s investments by contractual maturity as of September 30, 2023: September 30, 2023 Amortized Cost Fair Value Due within one year $ 175,144 $ 175,153 Total $ 175,144 $ 175,153

Goodwill and Intangible Assets

Goodwill and Intangible Assets	9 Months Ended
	Sep. 30, 2023
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill and Intangible Assets	Goodwill and Intangible Assets As of September 30, 2023 and December 31, 2022, goodwill was $1,814 and $1,798, respectively. Changes in goodwill during the three and nine months ended September 30, 2023 and 2022, respectively, are the result of foreign currency movements only. As of September 30, 2023, there have been no cumulative goodwill impairments recognized. Components of the Company's acquired intangible assets are comprised of the following: September 30, 2023 December 31, 2022 Gross carrying amount Accumulated amortization and impairment Net Gross carrying amount Accumulated amortization and impairment Net Discuva platform acquired $ 13,019 $ (13,019) $ — $ 12,900 $ (12,900) $ — Utrophin program acquired — — — 4,015 (4,015) — Option over non-financial asset 824 (824) — 816 (816) — Other licenses 134 (134) — 133 (133) — $ 13,977 $ (13,977) $ — $ 17,864 $ (17,864) $ — For the three and nine months ended September 30, 2023, amortization expense was $0, respectively. For the three and nine months ended September 30, 2022, amortization expense was $217 and $697, respectively. Changes in the gross carrying amount are the result of foreign currency movements. During the nine months ended September 30, 2023, the Company dissolved the wholly-owned subsidiary, Muox Limited, a dormant entity. The Utrophin program intangible assets, which arose from the Muox Limited acquisition, were fully impaired and have now been removed from the Company's accounting records.

Leases

Leases	9 Months Ended
	Sep. 30, 2023
Leases [Abstract]
Leases	Leases The Company has operating leases for real estate. The Company does not have any finance leases. During the nine months ended September 30, 2023, the Company recorded $4,245 of additional right-of-use assets related to a new lease for office space that commenced during the period in its Menlo Park, California location. The Company will make total lease payments of $4,701 over the 36 month term of the new lease, which expires in May 2026. In addition, during the nine months ended September 30, 2023, the Company terminated the Company's Cambridge, U.K. laboratory and office space lease as a result of the Company re-prioritizing its investments and financial resources towards the development of ivonescimab. This resulted in disposing the carrying value of the right-of use asset of $788, and there were no penalties charged for early termination of this lease. The Company recorded $2,756 of new right-of-use assets during the nine month periods ended September 30, 2022 related to its Menlo Park, California location. The carrying value of the right-of-use assets as of September 30, 2023 and December 31, 2022 was $6,403 and $4,175, respectively. Lease Cost: Three Months Ended Nine Months Ended 2023 2022 2023 2022 Fixed lease costs $ 678 $ 444 $ 1,535 $ 1,033 Variable lease costs 2 53 71 91 Total lease cost $ 680 $ 497 $ 1,606 $ 1,124 Short-term lease costs for each of the three and nine month periods ended September 30, 2023 and 2022 were immaterial. Other information: Nine Months Ended September 30, 2023 Nine Months Ended September 30, 2022 Operating cash flows used for operating leases $ 1,519 $ 891 Weighted average remaining lease term (years) 2.6 3.6 Weighted average discount rate 6.5 % 5.7 %

Promissory Notes Payable to Rel

Promissory Notes Payable to Related Parties	9 Months Ended
	Sep. 30, 2023
Related Party Transactions [Abstract]
Promissory Notes Payable to Related Parties	Promissory Notes Payable to Related Parties Non-current and current debt consisted of the following: Current notes Non-current notes September 30, 2023 December 31, 2022 September 30, 2023 December 31, 2022 Principal amounts $ 100,000 $ 20,000 $ — $ 500,000 Debt discount — (230) — (5,460) Total promissory notes payable to related parties $ 100,000 $ 19,770 $ — $ 494,540 On December 6, 2022, the Company entered into a Note Purchase Agreement (the "Note Purchase Agreement"), with Mr. Duggan and Dr. Zanganeh, pursuant to which the Company agreed to sell to each of Mr. Duggan and Dr. Zanganeh unsecured promissory notes in the aggregate amount of $520,000. Pursuant to the Note Purchase Agreement, the Company issued to Mr. Duggan and Dr. Zanganeh unsecured promissory notes in the amount of $400,000 (the "Duggan February Note") and $20,000 (the "Zanganeh Note"), respectively, which would mature and become due on February 15, 2023 and an unsecured promissory note to Mr. Duggan in the amount of $100,000 (the “Duggan September Note” and together with the Duggan February Note and the Zanganeh Note, the “December 2022 Notes”), which would mature and become due on September 15, 2023. The maturity dates of the December 2022 Notes could be extended one or more times at the Company’s election, but in no event to a date later than September 6, 2024. In addition, if the Company shall consummate a public offering, then upon the later to occur of (i) five On January 19, 2023, the Company provided notice to extend the term of the Duggan February Note and Duggan September Note to a maturity date of September 6, 2024. Furthermore, on January 19, 2023, the Company and Mr. Duggan rectified the Duggan February Note and Duggan September Note in order to correctly reflect the parties’ intent that the Company may only prepay (i) the Duggan February Note following the completion of a public rights offering to be conducted by Summit in the approximate amount of $500,000, or a similar capital raise, in an amount equal to the lesser of (x) the net proceeds of the Rights Offering or such capital raise or (y) the full amount outstanding of the Duggan February Note, and (ii) Duggan September Note following the completion of a capital raising transaction subsequent to the 2023 Rights Offering in an amount equal to the lesser of (i) the net proceeds of such capital raise or (ii) the full amount outstanding of the Duggan September Note. Following the issuance of the two new Promissory Notes (the “Duggan Promissory Notes”), the Duggan February Note and Duggan September Note were marked as “cancelled” on their face and replaced in their entirety by the Duggan Promissory Notes (together with the Zanganeh Note, the "Notes"). On February 15, 2023, the $20,000 Zanganeh Note matured and the Company repaid the outstanding principal balance. In connection with the closing of the 2023 Rights Offering, the $400,000 Duggan Promissory Note matured and became due, and the Company satisfied all principal and accrued interest thereunder using a combination of a portion of the cash proceeds from the 2023 Rights Offering and the extinguishment of a portion of the amount due equal to the subscription price for shares subscribed by Mr. Duggan in the 2023 Rights Offering. The Notes accrued interest at an initial rate of 7.5%. All interest on the Notes was paid on the date of signing for the period through February 15, 2023. Such prepaid interest was paid in a number of shares of the Company’s common stock, par value $0.01 (“Common Stock”) equal to the dollar amount of such prepaid interest, divided by $0.7913 (the consolidated closing bid price immediately preceding the time the Company entered into the Note Purchase Agreement, plus $0.01), which was 9,720,291 shares. For all applicable periods following the February 15, 2023, interest shall accrue on the outstanding principal balance of the Notes at the US prime interest rate, as reported in the Wall Street Journal, plus 50 basis points, as adjusted monthly, for three months immediately following February 15, 2023, and thereafter at the US prime rate plus 300 basis points, as adjusted monthly. Such accrued interest shall be paid in cash, quarterly in arrears, on each of March 31, June 30, September 30 and December 31. Debt issuance costs associated with the Notes were $44 and were capitalized as part of the carrying value of the promissory notes payable to related parties. During the three and nine months ended September 30, 2023, the Company incurred interest expense of $2,722 and $13,564 respectively. Interest expense incurred during the nine months ended September 30, 2023 included amortized imputed interest of $761. As of September 30, 2023 and as of December 31, 2022, there was no accrued interest payable included within accrued expenses in the condensed consolidated balance sheets. The $100,000 Duggan September Note is due September 6, 2024. Imputed interest is calculated as the difference between the expected interest payable and the deemed market rate of interest and is recorded as a debt discount at inception of the note payable with a credit to additional paid-in capital for notes payable to related parties. The debt discount is amortized to interest expense using an effective interest rate method. The effective interest rate of the Duggan February Note and Zanganeh Note was 8.9% and the effective interest rate of the Duggan September Note is 11.2%. As of September 30, 2023, the estimated future principal payments due were as follows: As of September 30, 2023 2023 $ — 2024 100,000 $ 100,000 July 25, 2022 First Amendment to Sublease Agreement with Maky Zanganeh and Associates, Inc. On July 25, 2022 the Company entered into a first amendment, dated July 19, 2022, to its initial sublease agreement with Maky Zanganeh and Associates, Inc. ("MZA") consisting of 4,500 square feet of office space at 2882 Sand Hill Road, Menlo Park, California entered into on March 26, 2021. The sublease term, which was set to expire on September 30, 2022, was extended for a period of thirty-nine months from October 1, 2022 through December 31, 2025. The rent payable under the terms of the sublease is equivalent to the proportionate share of the net payable by MZA to the third-party landlord, based on the square footage of office space sublet by the Company, and no mark-up has been applied. During the three and nine months ended September 30, 2023, payments of $189 and $567, were made pursuant to the first amendment to the Sublease Agreement. During the three and nine months ended September 30, 2022, payments of $179 and $537, were made pursuant to the initial Sublease Agreement. July 29, 2022 Second Amendment to Sublease Agreement with Maky Zanganeh and Associates, Inc. On July 29, 2022, the Company entered into a second amendment, dated August 1, 2022, to its existing sublease agreement with MZA, described above. The second amendment was effective as of August 1, 2022 and expires on December 31, 2025. The second amendment includes an additional 1,277 square feet (the "Expansion Premises") of office space at 2882 Sand Hill Road, Menlo Park, California. The rent payable under the terms of the sublease is equivalent to the proportionate share of the net payable by MZA to the third-party landlord, based on the square footage of office space sublet by the Company, and no mark-up has been applied. During the three and nine months ended September 30, 2023, payments of $55 and $163 respectively, were made pursuant to the second amendment to the Sublease Agreement. March 10, 2022 Note Purchase Agreement On March 10, 2022, the Company entered into a Note Purchase Agreement (the "March 2022 Note"), with Mr. Duggan, pursuant to which Mr. Duggan loaned the Company $25,000 in exchange for the issuance by the Company of an unsecured promissory note in the amount of $25,000. The March 2022 Note accrued interest at a rate per annum equal to the prime rate as reported in the Wall Street Journal , which was 3.25% as of the effective date and 4.75% as of June 30, 2022. The March 2022 Note, including accrued interest, became due upon the earlier of (i) the consummation of a registered public offering with net proceeds of no less than $25,000 or (ii) 18 months from the date of issuance of the March 2022 Note, and was repaid on August 10, 2022. 2022 Rights Offering ("2022 Rights Offering") In August 2022, the Company announced the closing and final results of its previously announced rights offering. The 2022 Rights Offering commenced on July 18, 2022, and the associated subscription rights expired on August 8, 2022. Aggregate gross proceeds received from the rights offering were $100,000 from the sale of 103,092,783 shares of common stock. Mr. Duggan and Dr. Zanganeh fully subscribed to their respective basic subscription rights and oversubscribed, at a price of $0.97 per share. Issuance costs were $111. In connection with the closing of the 2022 Rights Offering, the March 2022 Note matured and became due, and the Company repaid all principal and accrued interest thereunder using a portion of the proceeds from the 2022 Rights Offering on August 10, 2022. December 6, 2022 Note Purchase Agreement On December 6, 2022, the Company entered into a Note Purchase Agreement (the "Note Purchase Agreement"), with Mr. Duggan and Dr. Zanganeh, pursuant to which the Company agreed to sell to each of Mr. Duggan and Dr. Zanganeh unsecured promissory notes in the aggregate amount of $520,000. Pursuant to the Note Purchase Agreement, the Company issued to Mr. Duggan and Dr. Zanganeh unsecured promissory notes in the amount of $400,000 (the "Duggan February Note") and $20,000 (the "Zanganeh Note"), respectively, which would mature and become due on February 15, 2023 and an unsecured promissory note to Mr. Duggan in the amount of $100,000 (the “Duggan September Note” and together with the Duggan February Note and the Zanganeh Note, the “December 2022 Notes”), which will mature and become due on September 15, 2023. The maturity dates of the December 2022 Notes could be extended one or more times at the Company’s election, but in no event to a date later than September 6, 2024. In addition, if the Company shall consummate a public offering, then upon the later to occur of (i) five On January 19, 2023, the Company provided notice to extend the term of the Duggan February Note and Duggan September Note to a maturity date of September 6, 2024. Furthermore, on January 19, 2023, the Company and Mr. Duggan rectified the Duggan February Note and Duggan September Note in order to correctly reflect the parties’ intent that the Company may only prepay (i) the Duggan February Note following the completion of a public rights offering to be conducted by Summit in the approximate amount of $500,000, or a similar capital raise, in an amount equal to the lesser of (x) the net proceeds of the 2023 Rights Offering or such capital raise or (y) the full amount outstanding of the Duggan February Note, and (ii) Duggan September Note following the completion of a capital raising transaction subsequent to the 2023 Rights Offering in an amount equal to the lesser of (i) the net proceeds of such capital raise or (ii) the full amount outstanding of the Duggan September Note. Following the issuance of the two new Promissory Notes, the Duggan Promissory Notes, the Duggan February Note and Duggan September Note were marked as “cancelled” on their face and replaced in their entirety by the Duggan Promissory Notes. On February 15, 2023, the $20,000 Zanganeh Note, matured and the Company repaid the outstanding principal balance. In connection with the closing of the 2023 Rights Offering, the $400,000 Duggan Promissory Note, matured and became due, and the Company satisfied all principal and accrued interest thereunder using a combination of a portion of the cash proceeds from the 2023 Rights Offering and the extinguishment of a portion of the amount due equal to the subscription price for shares subscribed by Mr. Duggan in the 2023 Rights Offering (as defined above). The Notes accrue interest at an initial rate of 7.5%. All interest on the Notes was paid on the date of signing for the period through February 15, 2023. Such prepaid interest was paid in a number of shares of the Company’s Common Stock equal to the dollar amount of such prepaid interest, divided by $0.7913 (the consolidated closing bid price immediately preceding the time the Company entered into the Note Purchase Agreement, plus $0.01), which was 9,720,291 shares. For all applicable periods following the February 15, 2023, interest shall accrue on the outstanding principal balance of the Notes at the United States prime interest rate, as reported in the Wall Street Journal, plus 50 basis points, as adjusted monthly, for three months immediately following February 15, 2023, and thereafter at the United States prime rate plus 300 basis points, as adjusted monthly. During the three and nine months ended September 30, 2023, the Company made payments for interest of $2,917 and $7,711, respectively. Akeso License Agreement Upon the closing of the License Agreement, the Board of Directors (the “Board”) of the Company appointed Dr. Yu (Michelle) Xia to serve as a member of the Board pursuant to the terms of the License Agreement. Dr. Xia is the founder of Akeso, Inc., and has been the chairwoman, president and CEO of the Company since its inception in 2012. For details on the License Agreement, see Note 8. Furthermore, in connection with the License Agreement, the Company also entered into a Supply Agreement with Akeso, pursuant to which Summit agreed to purchase a certain portion of drug substance for clinical and commercial supply (the “Supply Agreement”). All transactions pursuant to the Supply Agreement, which occurred during 2023, were in the ordinary course of business. 2023 Rights Offering On December 6, 2022, the Company announced a rights offering for its existing shareholders to participate in the purchase of additional shares of its Common Stock for $1.05 per share. The 2023 Rights Offering commenced on February 7, 2023 and the associated subscription rights expired on March 1, 2023. Aggregate gross proceeds from the 2023 Rights Offering were $500,000 from the sale of 476,190,471 shares of the Company's common stock and issuance costs were $619. Mr. Duggan and Dr. Zanganeh fully subscribed to their respective basic subscription rights at a price of $1.05 per share. To satisfy the $395,314 subscription price for the shares subscribed by Mr. Duggan in the 2023 Rights Offering, Mr. Duggan agreed with the Company to extinguish a portion of the amount due and payable to him by the Company at the closing of the 2023 Rights Offering pursuant to the $400,000 Duggan Promissory Note in an amount equal to the subscription price. Registration of Shares On March 17, 2023, the Company filed a registration statement on Form S-3 to register for resale the following shares of the Company's common stock at $0.01 par value: (i) 10,000,000 shares of Common Stock issued on January 17, 2023 in connection with the License Agreement with Akeso pursuant to which the Company issued Akeso such shares; and (ii) the 9,346,434 and 373,857 shares of Common Stock issued in December 2022 to the Company's Co-CEOs, Mr. Duggan and Dr. Zanganeh, respectively, as payment of prepaid interest in connection with the Note Purchase Agreement dated December 6, 2022 between Mr. Duggan, Dr. Zanganeh and the Company. On April 27, 2023, the SEC issued the Company a Notice of Effectiveness for the registration statement on Form S-3. Private Placement On October 16, 2023, the Company announced the appointment of Mr. Manmeet Soni as its Chief Operating Officer, effective immediately. Mr. Soni has been a part of the Company's Board of Directors since 2019. He will remain a member of the Board of Directors. In conjunction with his appointment, Mr. Soni entered into a share purchase agreement with the Company to purchase $5,000 of its common stock via a private placement. The transaction was effective October 13, 2023 with a closing price of $1.68, resulting in the purchase of 2,976,190 shares of the Company's common stock.

Stock-Based Compensation and Wa

Stock-Based Compensation and Warrants	9 Months Ended
	Sep. 30, 2023
Share-Based Payment Arrangement [Abstract]
Stock-Based Compensation and Warrants	Stock-Based Compensation and Warrants The Company currently grants stock options to employees and directors under the 2020 Stock Incentive Plan (the "2020 Plan") and formerly, the Company granted stock options under the 2016 Long Term Incentive Plan (the "2016 Plan"). The 2020 Plan is administered by the Compensation Committee of the Company's Board of Directors. The 2020 Plan is intended to attract and retain employees and directors and provide an incentive for these individuals to assist the Company to achieve long-range performance goals and to enable these individuals to participate in the long-term growth of the Company. On October 12, 2023, the Company held a Special Meeting of Stockholders (the "October Special Meeting") whereby the following matter was submitted to a vote of the Company's stockholders at the Special Meeting and the Board of Directors resolved the following: an amendment to the Summit Therapeutics Inc. 2020 Stock Incentive Plan (the "Plan") to increase the number of shares of the Company's common stock issuable under the Plan by 70,000,000 shares. The following table presents the stock option activity for both the 2016 Plan and the 2020 Plan as of September 30, 2023: Nine Months Ended Weighted average exercise price Outstanding at December 31, 2022 19,476,359 $ 3.55 Granted 3,921,450 2.14 Forfeited (2,672,305) 3.98 Exercised (177,237) 2.26 Outstanding at September 30, 2023 20,548,267 $ 3.24 Exercisable at September 30, 2023 5,273,780 $ 5.14 The total intrinsic value of all outstanding and exercisable stock options at September 30, 2023 was $5,683 and $280, respectively. The aggregate intrinsic value of stock options is calculated as the difference between the exercise price of the stock options and the fair value of the Company’s common stock for those stock options that had exercise prices lower than the fair value of the Company’s common stock. The total stock-based compensation expense included in the Company's condensed consolidated statements of operations and comprehensive loss was as follows: Three Months Ended September 30, Nine Months Ended September 30, 2023 2022 2023 2022 Research and development $ 149 $ 1,162 $ 1,962 $ 3,300 General and administrative 556 1,636 3,393 5,990 Total stock-based compensation expense $ 705 $ 2,798 $ 5,355 $ 9,290 Warrants The Company had outstanding and exercisable warrants of 5,821,137 with a weighted average exercise price of $1.56 as of September 30, 2023 and December 31, 2022.

Related Party Transactions

Related Party Transactions	9 Months Ended
	Sep. 30, 2023
Related Party Transactions [Abstract]
Related Party Transactions	Promissory Notes Payable to Related Parties Non-current and current debt consisted of the following: Current notes Non-current notes September 30, 2023 December 31, 2022 September 30, 2023 December 31, 2022 Principal amounts $ 100,000 $ 20,000 $ — $ 500,000 Debt discount — (230) — (5,460) Total promissory notes payable to related parties $ 100,000 $ 19,770 $ — $ 494,540 On December 6, 2022, the Company entered into a Note Purchase Agreement (the "Note Purchase Agreement"), with Mr. Duggan and Dr. Zanganeh, pursuant to which the Company agreed to sell to each of Mr. Duggan and Dr. Zanganeh unsecured promissory notes in the aggregate amount of $520,000. Pursuant to the Note Purchase Agreement, the Company issued to Mr. Duggan and Dr. Zanganeh unsecured promissory notes in the amount of $400,000 (the "Duggan February Note") and $20,000 (the "Zanganeh Note"), respectively, which would mature and become due on February 15, 2023 and an unsecured promissory note to Mr. Duggan in the amount of $100,000 (the “Duggan September Note” and together with the Duggan February Note and the Zanganeh Note, the “December 2022 Notes”), which would mature and become due on September 15, 2023. The maturity dates of the December 2022 Notes could be extended one or more times at the Company’s election, but in no event to a date later than September 6, 2024. In addition, if the Company shall consummate a public offering, then upon the later to occur of (i) five On January 19, 2023, the Company provided notice to extend the term of the Duggan February Note and Duggan September Note to a maturity date of September 6, 2024. Furthermore, on January 19, 2023, the Company and Mr. Duggan rectified the Duggan February Note and Duggan September Note in order to correctly reflect the parties’ intent that the Company may only prepay (i) the Duggan February Note following the completion of a public rights offering to be conducted by Summit in the approximate amount of $500,000, or a similar capital raise, in an amount equal to the lesser of (x) the net proceeds of the Rights Offering or such capital raise or (y) the full amount outstanding of the Duggan February Note, and (ii) Duggan September Note following the completion of a capital raising transaction subsequent to the 2023 Rights Offering in an amount equal to the lesser of (i) the net proceeds of such capital raise or (ii) the full amount outstanding of the Duggan September Note. Following the issuance of the two new Promissory Notes (the “Duggan Promissory Notes”), the Duggan February Note and Duggan September Note were marked as “cancelled” on their face and replaced in their entirety by the Duggan Promissory Notes (together with the Zanganeh Note, the "Notes"). On February 15, 2023, the $20,000 Zanganeh Note matured and the Company repaid the outstanding principal balance. In connection with the closing of the 2023 Rights Offering, the $400,000 Duggan Promissory Note matured and became due, and the Company satisfied all principal and accrued interest thereunder using a combination of a portion of the cash proceeds from the 2023 Rights Offering and the extinguishment of a portion of the amount due equal to the subscription price for shares subscribed by Mr. Duggan in the 2023 Rights Offering. The Notes accrued interest at an initial rate of 7.5%. All interest on the Notes was paid on the date of signing for the period through February 15, 2023. Such prepaid interest was paid in a number of shares of the Company’s common stock, par value $0.01 (“Common Stock”) equal to the dollar amount of such prepaid interest, divided by $0.7913 (the consolidated closing bid price immediately preceding the time the Company entered into the Note Purchase Agreement, plus $0.01), which was 9,720,291 shares. For all applicable periods following the February 15, 2023, interest shall accrue on the outstanding principal balance of the Notes at the US prime interest rate, as reported in the Wall Street Journal, plus 50 basis points, as adjusted monthly, for three months immediately following February 15, 2023, and thereafter at the US prime rate plus 300 basis points, as adjusted monthly. Such accrued interest shall be paid in cash, quarterly in arrears, on each of March 31, June 30, September 30 and December 31. Debt issuance costs associated with the Notes were $44 and were capitalized as part of the carrying value of the promissory notes payable to related parties. During the three and nine months ended September 30, 2023, the Company incurred interest expense of $2,722 and $13,564 respectively. Interest expense incurred during the nine months ended September 30, 2023 included amortized imputed interest of $761. As of September 30, 2023 and as of December 31, 2022, there was no accrued interest payable included within accrued expenses in the condensed consolidated balance sheets. The $100,000 Duggan September Note is due September 6, 2024. Imputed interest is calculated as the difference between the expected interest payable and the deemed market rate of interest and is recorded as a debt discount at inception of the note payable with a credit to additional paid-in capital for notes payable to related parties. The debt discount is amortized to interest expense using an effective interest rate method. The effective interest rate of the Duggan February Note and Zanganeh Note was 8.9% and the effective interest rate of the Duggan September Note is 11.2%. As of September 30, 2023, the estimated future principal payments due were as follows: As of September 30, 2023 2023 $ — 2024 100,000 $ 100,000 July 25, 2022 First Amendment to Sublease Agreement with Maky Zanganeh and Associates, Inc. On July 25, 2022 the Company entered into a first amendment, dated July 19, 2022, to its initial sublease agreement with Maky Zanganeh and Associates, Inc. ("MZA") consisting of 4,500 square feet of office space at 2882 Sand Hill Road, Menlo Park, California entered into on March 26, 2021. The sublease term, which was set to expire on September 30, 2022, was extended for a period of thirty-nine months from October 1, 2022 through December 31, 2025. The rent payable under the terms of the sublease is equivalent to the proportionate share of the net payable by MZA to the third-party landlord, based on the square footage of office space sublet by the Company, and no mark-up has been applied. During the three and nine months ended September 30, 2023, payments of $189 and $567, were made pursuant to the first amendment to the Sublease Agreement. During the three and nine months ended September 30, 2022, payments of $179 and $537, were made pursuant to the initial Sublease Agreement. July 29, 2022 Second Amendment to Sublease Agreement with Maky Zanganeh and Associates, Inc. On July 29, 2022, the Company entered into a second amendment, dated August 1, 2022, to its existing sublease agreement with MZA, described above. The second amendment was effective as of August 1, 2022 and expires on December 31, 2025. The second amendment includes an additional 1,277 square feet (the "Expansion Premises") of office space at 2882 Sand Hill Road, Menlo Park, California. The rent payable under the terms of the sublease is equivalent to the proportionate share of the net payable by MZA to the third-party landlord, based on the square footage of office space sublet by the Company, and no mark-up has been applied. During the three and nine months ended September 30, 2023, payments of $55 and $163 respectively, were made pursuant to the second amendment to the Sublease Agreement. March 10, 2022 Note Purchase Agreement On March 10, 2022, the Company entered into a Note Purchase Agreement (the "March 2022 Note"), with Mr. Duggan, pursuant to which Mr. Duggan loaned the Company $25,000 in exchange for the issuance by the Company of an unsecured promissory note in the amount of $25,000. The March 2022 Note accrued interest at a rate per annum equal to the prime rate as reported in the Wall Street Journal , which was 3.25% as of the effective date and 4.75% as of June 30, 2022. The March 2022 Note, including accrued interest, became due upon the earlier of (i) the consummation of a registered public offering with net proceeds of no less than $25,000 or (ii) 18 months from the date of issuance of the March 2022 Note, and was repaid on August 10, 2022. 2022 Rights Offering ("2022 Rights Offering") In August 2022, the Company announced the closing and final results of its previously announced rights offering. The 2022 Rights Offering commenced on July 18, 2022, and the associated subscription rights expired on August 8, 2022. Aggregate gross proceeds received from the rights offering were $100,000 from the sale of 103,092,783 shares of common stock. Mr. Duggan and Dr. Zanganeh fully subscribed to their respective basic subscription rights and oversubscribed, at a price of $0.97 per share. Issuance costs were $111. In connection with the closing of the 2022 Rights Offering, the March 2022 Note matured and became due, and the Company repaid all principal and accrued interest thereunder using a portion of the proceeds from the 2022 Rights Offering on August 10, 2022. December 6, 2022 Note Purchase Agreement On December 6, 2022, the Company entered into a Note Purchase Agreement (the "Note Purchase Agreement"), with Mr. Duggan and Dr. Zanganeh, pursuant to which the Company agreed to sell to each of Mr. Duggan and Dr. Zanganeh unsecured promissory notes in the aggregate amount of $520,000. Pursuant to the Note Purchase Agreement, the Company issued to Mr. Duggan and Dr. Zanganeh unsecured promissory notes in the amount of $400,000 (the "Duggan February Note") and $20,000 (the "Zanganeh Note"), respectively, which would mature and become due on February 15, 2023 and an unsecured promissory note to Mr. Duggan in the amount of $100,000 (the “Duggan September Note” and together with the Duggan February Note and the Zanganeh Note, the “December 2022 Notes”), which will mature and become due on September 15, 2023. The maturity dates of the December 2022 Notes could be extended one or more times at the Company’s election, but in no event to a date later than September 6, 2024. In addition, if the Company shall consummate a public offering, then upon the later to occur of (i) five On January 19, 2023, the Company provided notice to extend the term of the Duggan February Note and Duggan September Note to a maturity date of September 6, 2024. Furthermore, on January 19, 2023, the Company and Mr. Duggan rectified the Duggan February Note and Duggan September Note in order to correctly reflect the parties’ intent that the Company may only prepay (i) the Duggan February Note following the completion of a public rights offering to be conducted by Summit in the approximate amount of $500,000, or a similar capital raise, in an amount equal to the lesser of (x) the net proceeds of the 2023 Rights Offering or such capital raise or (y) the full amount outstanding of the Duggan February Note, and (ii) Duggan September Note following the completion of a capital raising transaction subsequent to the 2023 Rights Offering in an amount equal to the lesser of (i) the net proceeds of such capital raise or (ii) the full amount outstanding of the Duggan September Note. Following the issuance of the two new Promissory Notes, the Duggan Promissory Notes, the Duggan February Note and Duggan September Note were marked as “cancelled” on their face and replaced in their entirety by the Duggan Promissory Notes. On February 15, 2023, the $20,000 Zanganeh Note, matured and the Company repaid the outstanding principal balance. In connection with the closing of the 2023 Rights Offering, the $400,000 Duggan Promissory Note, matured and became due, and the Company satisfied all principal and accrued interest thereunder using a combination of a portion of the cash proceeds from the 2023 Rights Offering and the extinguishment of a portion of the amount due equal to the subscription price for shares subscribed by Mr. Duggan in the 2023 Rights Offering (as defined above). The Notes accrue interest at an initial rate of 7.5%. All interest on the Notes was paid on the date of signing for the period through February 15, 2023. Such prepaid interest was paid in a number of shares of the Company’s Common Stock equal to the dollar amount of such prepaid interest, divided by $0.7913 (the consolidated closing bid price immediately preceding the time the Company entered into the Note Purchase Agreement, plus $0.01), which was 9,720,291 shares. For all applicable periods following the February 15, 2023, interest shall accrue on the outstanding principal balance of the Notes at the United States prime interest rate, as reported in the Wall Street Journal, plus 50 basis points, as adjusted monthly, for three months immediately following February 15, 2023, and thereafter at the United States prime rate plus 300 basis points, as adjusted monthly. During the three and nine months ended September 30, 2023, the Company made payments for interest of $2,917 and $7,711, respectively. Akeso License Agreement Upon the closing of the License Agreement, the Board of Directors (the “Board”) of the Company appointed Dr. Yu (Michelle) Xia to serve as a member of the Board pursuant to the terms of the License Agreement. Dr. Xia is the founder of Akeso, Inc., and has been the chairwoman, president and CEO of the Company since its inception in 2012. For details on the License Agreement, see Note 8. Furthermore, in connection with the License Agreement, the Company also entered into a Supply Agreement with Akeso, pursuant to which Summit agreed to purchase a certain portion of drug substance for clinical and commercial supply (the “Supply Agreement”). All transactions pursuant to the Supply Agreement, which occurred during 2023, were in the ordinary course of business. 2023 Rights Offering On December 6, 2022, the Company announced a rights offering for its existing shareholders to participate in the purchase of additional shares of its Common Stock for $1.05 per share. The 2023 Rights Offering commenced on February 7, 2023 and the associated subscription rights expired on March 1, 2023. Aggregate gross proceeds from the 2023 Rights Offering were $500,000 from the sale of 476,190,471 shares of the Company's common stock and issuance costs were $619. Mr. Duggan and Dr. Zanganeh fully subscribed to their respective basic subscription rights at a price of $1.05 per share. To satisfy the $395,314 subscription price for the shares subscribed by Mr. Duggan in the 2023 Rights Offering, Mr. Duggan agreed with the Company to extinguish a portion of the amount due and payable to him by the Company at the closing of the 2023 Rights Offering pursuant to the $400,000 Duggan Promissory Note in an amount equal to the subscription price. Registration of Shares On March 17, 2023, the Company filed a registration statement on Form S-3 to register for resale the following shares of the Company's common stock at $0.01 par value: (i) 10,000,000 shares of Common Stock issued on January 17, 2023 in connection with the License Agreement with Akeso pursuant to which the Company issued Akeso such shares; and (ii) the 9,346,434 and 373,857 shares of Common Stock issued in December 2022 to the Company's Co-CEOs, Mr. Duggan and Dr. Zanganeh, respectively, as payment of prepaid interest in connection with the Note Purchase Agreement dated December 6, 2022 between Mr. Duggan, Dr. Zanganeh and the Company. On April 27, 2023, the SEC issued the Company a Notice of Effectiveness for the registration statement on Form S-3. Private Placement On October 16, 2023, the Company announced the appointment of Mr. Manmeet Soni as its Chief Operating Officer, effective immediately. Mr. Soni has been a part of the Company's Board of Directors since 2019. He will remain a member of the Board of Directors. In conjunction with his appointment, Mr. Soni entered into a share purchase agreement with the Company to purchase $5,000 of its common stock via a private placement. The transaction was effective October 13, 2023 with a closing price of $1.68, resulting in the purchase of 2,976,190 shares of the Company's common stock.

Commitment and Contingencies

Commitment and Contingencies	9 Months Ended
	Sep. 30, 2023
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Commitments and Contingencies Fixed Asset Purchase Commitments As of September 30, 2023 and December 31, 2022, the Company had no capital commitments. Lease Commitments The Company leases office space in Menlo Park, California, United States and in Oxfordshire, United Kingdom. There have been no material changes to the Company's lease commitments as of December 31, 2022 which were disclosed in the Company's Annual Report on Form 10-K for the year ended December 31, 2022, filed with the Securities and Exchange Commission on March 9, 2023, other than the Company's new lease in its Menlo Park, California, U.S. location and the termination of the Company's Cambridge, U.K. laboratory and office space lease as a result of the Company re-prioritizing its investments and financial resources towards the development of ivonescimab, as described in Note 13. Debt commitments Refer to Note 14 for discussion of promissory notes payable to related parties. Other Commitments The Company enters into contracts in the normal course of business with various third parties for clinical trials, preclinical research studies and testing, manufacturing and other services and products for operating purposes. Most contracts provide for termination upon notice, and therefore are cancellable contracts. There have been no material changes to the Company's other contractual commitments as of December 31, 2022 which were disclosed in the Company's Annual Report on Form 10-K, filed with the Securities and Exchange Commission on March 9, 2023, other than approximately $6,356 of non-cancellable purchase commitments associated with our clinical trials as of September 30, 2023. The Company has certain commitments under its agreements with the Akeso, Wellcome Trust, the University College London and certain employees, former employees and former directors of Discuva, pursuant to which it will be required to pay royalties or make milestone payments. The License Agreement with Akeso also contains certain manufacturing and purchase commitments. As of September 30, 2023, the Company is unable to estimate the amount, timing or likelihood of achieving the milestones, making future product sales or assessing estimated forecasts for manufacturing and supplied materials which these contingent payment obligations relate to. Indemnifications The Company's certificate of incorporation provides that it will indemnify the directors and officers to the fullest extent permitted by Delaware law. In addition, the Company has entered into indemnification agreements with all of the directors and executive officers. These indemnification agreements may require the Company, among other things, to indemnify each such director or executive officer for some expenses, including attorneys’ fees, judgments, fines, and settlement amounts incurred by him or her in any action or proceeding arising out of his or her service as one of the Company's directors or executive officers. The Company believes the fair value for these indemnification obligations is minimal. Accordingly, the Company has not recognized any liabilities relating to these obligations as of September 30, 2023 and December 31, 2022. Legal Proceedings The Company is not currently subject to any material legal proceedings.

Subsequent Events

Subsequent Events	9 Months Ended
	Sep. 30, 2023
Subsequent Events [Abstract]
Subsequent Events	Subsequent EventsOn October 16, 2023, the Company announced the appointment of Mr. Manmeet Soni as its Chief Operating Officer, effective immediately. Mr. Soni has been a part of the Company's Board of Directors since 2019. He will remain a member of the Board of Directors. In conjunction with his appointment, Mr. Soni entered into a share purchase agreement with the Company to purchase $5,000 of its common stock via a private placement. The transaction was effective October 13, 2023 with a closing price of $1.68, resulting in the purchase of 2,976,190 shares of the Company's common stock.

Basis of Presentation, Use of_2

Basis of Presentation, Use of Estimates, and Risks and Uncertainties (Policies)	9 Months Ended
	Sep. 30, 2023
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Basis of Presentation	Basis of Presentation The accompanying unaudited condensed consolidated financial statements have been prepared in accordance with accounting principles generally accepted in the United States ("U.S. GAAP") and pursuant to the rules and regulations of the U.S. Securities and Exchange Commission. Accordingly, certain information and disclosures required by U.S. GAAP for complete consolidated financial statements are not included herein. All intercompany accounts and transactions have been eliminated in consolidation. The interim financial data as of September 30, 2023 and for the three and nine months ended September 30, 2023 are unaudited; however, in the opinion of management, the interim data includes all adjustments, consisting of normal recurring adjustments, necessary for a fair statement of the results for the interim periods. The condensed consolidated balance sheet presented as of December 31, 2022 has been derived from the consolidated audited financial statement as of that date. The results of the period are not necessarily indicative of full year results or any other interim period. These unaudited interim condensed consolidated financial statements should be read in conjunction with the audited financial statements and notes thereto of the Company which are included in the Summit Annual Report on Form 10-K for the year ended December 31, 2022 filed with the Securities and Exchange Commission on March 9, 2023. The financial results of the Company's activities are reported in United States Dollars.
Cash equivalents	Cash equivalentsDuring the nine months ended September 30, 2023, cash consisted of non-interest-bearing deposits denominated in the U.S. dollar and British pound, and the Company invested cash in money market funds and U.S. treasury securities. All highly liquid investments with a maturity date of 90 days or less at the date of purchase are considered to be cash equivalents. The appropriate classification of investments in securities as to whether it is classified as a cash equivalent is determined by the Company at the time of purchase.
Marketable securities	Marketable securities Marketable securities consist of investments with original maturities greater than ninety days from the date of acquisition. The Company classifies investments with maturities of greater than 90 days as short-term, based on the liquid nature of the securities and because such marketable securities represent the investment of cash that is available for current operations. The Company considers its investment portfolio of investments as available-for-sale. Accordingly, these investments are recorded at fair value, which is based on quoted market prices or other observable inputs. Unrealized gains and losses are recorded as a component of other comprehensive income (loss). Realized gains and losses are determined on a specific identification basis and are included in other (expense) income. Amortization and accretion of discounts and premiums is also recorded in other (expense) income. When the fair value is below the amortized cost of the asset, an estimate of expected credit losses is made, this estimate is limited to the amount by which fair value is less than amortized cost. The credit-related impairment amount is recognized in the condensed consolidated statements of operations and comprehensive loss and the remaining impairment amount and unrealized gains are reported as a component of accumulated other comprehensive income (loss) in shareholders’ equity. Credit losses are recognized through the use of an allowance for credit losses account and subsequent improvements in expected credit losses are recognized as a reversal of the allowance account. If the Company has the intent to sell the security or it is more likely than not that the Company will be required to sell the security prior to recovery of its amortized cost basis the allowance for credit loss is written off and the excess of the amortized cost basis of the asset over its fair value is recorded in the condensed consolidated statements of operations and comprehensive loss.
Use of Estimates	Use of Estimates The preparation of these unaudited condensed consolidated financial statements requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and the disclosure of contingent liabilities at the date of the unaudited condensed consolidated financial statements and the reported amounts of revenues and expenses during the reporting period. On an on-going basis, management evaluates its estimates and judgments, including those related to revenue recognition, accrued research and development expenses, stock-based compensation, intangible assets, goodwill, other long-lived assets and income taxes. Management bases its estimates and judgments on historical experience and on various other factors that are believed to be reasonable under the circumstances, the results of which form the basis for making judgments about the carrying values of assets and liabilities that are not readily apparent from other sources. Actual results may differ from these estimates under different assumptions or conditions.
Recently Issued or Adopted Accounting Pronouncements	Recently Issued or Adopted Accounting Pronouncements In June 2016, the FASB issued ASU 2016-13, "Financial Instruments - Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments", which has subsequently been amended by ASU 2019-04 and ASU 2019-10 (collectively "ASU 2016-03"). ASU 2016-13 amends the guidance on the impairment of financial instruments. This update adds an impairment model (known as the current expected credit losses model) that is based on expected losses rather than incurred losses. Under the new guidance, an entity recognizes, as an allowance, its estimate of expected credit losses. The Company adopted this standard on January 1, 2023, and it did not have a material impact on the condensed consolidated financial statements or related disclosures. In May 2021, the FASB issued ASU No. 2021-04, "Earnings Per Share (Topic 260), Debt - Modifications and Extinguishments (Subtopic 470-50), Compensation - Stock Compensation (Topic 718), and Derivatives and Hedging Contracts in Entity's Own Equity (Subtopic 815-40) - Issuer's Accounting for Certain Modifications or Exchanges of Freestanding Equity-Classified Written Call Options". This ASU provides clarification and reduces diversity in an issuer’s accounting for modifications or exchanges of freestanding equity-classified written call options (such as warrants) that remain equity classified after modification or exchange. This ASU is effective for annual periods, and interim periods within those fiscal years, beginning after December 15, 2021. The Company will apply this ASU on a prospective basis for any modifications or exchanges once this ASU is effective and at that time, will be able to determine the potential impact on its financial position, results of operations or cash flows. There have been no modifications or exchanges relating to this ASU during 2023 or 2022. Other recent authoritative guidance issued by the FASB (including technical corrections to the FASB ASC), the American Institute of Certified Public Accountants, and the SEC did not or are not expected to have a material impact on the Company's condensed consolidated financial statements.

Segment Reporting (Tables)

Segment Reporting (Tables)	9 Months Ended
	Sep. 30, 2023
Segment Reporting [Abstract]
Summary of long-lived assets by geography	The following table summarizes the Company's long-lived assets, which include the Company's property and equipment, net and right-of-use assets by geography: September 30, 2023 December 31, 2022 United Kingdom $ 832 $ 2,517 United States 5,800 2,564 $ 6,632 $ 5,081

Revenue (Tables)

Revenue (Tables)	9 Months Ended
	Sep. 30, 2023
Revenue from Contract with Customer [Abstract]
Summary of revenue by category	The following table summarizes revenue by category: Three Months Ended Nine Months Ended Revenue by category: 2023 2022 2023 2022 Licensing agreements $ — $ 220 $ — $ 705
Summary of revenue by geography	The following table summarizes revenue by geography: Three Months Ended Nine Months Ended Revenue by geography: 2023 2022 2023 2022 Latin America $ — $ 220 $ — $ 705
Summary of deferred revenue and other income	The following table summarizes the deferred revenue relating to the Company's license and commercialization agreement with Eurofarma Laboratórios S.A. and deferred other income relating to BARDA (as defined in Note 7): 2023 2022 Beginning deferred revenue and other income, January 1 (1) $ — $ 7,939 Additions — 956 Amount of deferred revenue and other income recognized in the statement of operations — (8,479) Foreign currency adjustments — (416) Ending deferred revenue and other income, September 30 (2) $ — $ — ____________ (1) Beginning deferred revenue and other income as of January 1, 2023 and 2022 included $0 of current and $0 of long-term deferred revenue and other income, and $7,939 of current and $0 of long-term deferred revenue and other income, respectively. (2) Ending deferred revenue and other income as of September 30, 2023 and 2022 included $0 of current and $0 of long-term deferred revenue and other income, and $0 of current and $0 of long-term deferred revenue and other income, respectively.

Other Operating Income, Net (Ta

Other Operating Income, Net (Tables)	9 Months Ended
	Sep. 30, 2023
Other Income and Expenses [Abstract]
Schedule of other operating (expense) income, net	The following table sets forth the components of other operating income by category: Three Months Ended Nine Months Ended Other operating (expense) income, net by category: 2023 2022 2023 2022 Funding income from BARDA (as defined below) $ — $ 3,889 $ — $ 7,774 Research and development tax credits 265 1,224 768 3,730 Grant income from CARB-X (as defined below) — 349 45 1,779 Other income — — 9 — $ 265 $ 5,462 $ 822 $ 13,283

Other (Expense) Income, Net (Ta

Other (Expense) Income, Net (Tables)	9 Months Ended
	Sep. 30, 2023
Other Income and Expenses [Abstract]
Schedule of other (expense) income, net	The following table sets forth the components of other (expense) income: Three Months Ended September 30, Nine Months Ended 2023 2022 2023 2022 Foreign currency gains (losses) $ (475) $ (3,799) $ 344 $ (6,281) Interest expense on promissory notes payable to related parties (2,722) (692) (13,564) (1,497) Interest income 2,485 — 8,028 — Reclassification of cumulative currency translation gain (1) — — 419 — Other expense (64) 46 (148) 15 $ (776) $ (4,445) $ (4,921) $ (7,763) (1) Effective January 17, 2023, the Company dissolved the following dormant entities; Summit (Cambridge) Limited, Summit (Wales) Limited, Summit Corporation Employee Benefit Trust Company Limited, Summit Corporation Limited, Summit Discovery 1 Limited and Summit Infectious Diseases Limited. As a result, the Company reclassified $419 of cumulative foreign currency translation adjustments from accumulated other comprehensive loss relating to these entities.

Loss per Share (Tables)

Loss per Share (Tables)	9 Months Ended
	Sep. 30, 2023
Earnings Per Share [Abstract]
Schedule of net loss per share	The following table sets forth the computation of basic and diluted net loss per share: Three Months Ended Nine Months Ended 2023 2022 2023 2022 Net loss $ (21,268) $ (21,385) $ (578,361) $ (59,553) Basic weighted average number of shares of common stock outstanding 697,739,477 208,909,351 592,366,880 161,846,345 Diluted weighted average number of shares of common stock outstanding 697,739,477 208,909,351 592,366,880 161,846,345 Basic net loss per share $ (0.03) $ (0.10) $ (0.98) $ (0.37) Diluted net loss per share $ (0.03) $ (0.10) $ (0.98) $ (0.37)
Schedule of potentially dilutive securities excluded from the computation of loss per share	The following potentially dilutive securities were excluded from the computation of the diluted net loss per share of common stock for the periods presented because their effect would have been anti-dilutive: September 30, 2023 2022 Options to purchase common stock 20,548,267 19,318,301 Warrants 5,821,137 5,821,137 Shares expected to be purchased under employee stock purchase plan 247,357 248,375 26,616,761 25,387,813

Fair Value Measurements and I_2

Fair Value Measurements and Investments (Tables)	9 Months Ended
	Sep. 30, 2023
Fair Value Disclosures [Abstract]
Schedule of assets measured at fair value on a recurring basis	The following tables sets forth the Company’s fair value hierarchy for its assets and liabilities that are measured at fair value on a recurring basis as of September 30, 2023 and December 31, 2022: Fair Value Measurements as of September 30, 2023 using: Level 1 Level 2 Level 3 Total Cash equivalents: Money market funds $ 4,711 $ — $ — $ 4,711 Short-term investments: U.S. Government treasury bills $ — $ 175,153 $ — $ 175,153 Total financial assets $ 4,711 $ 175,153 $ — $ 179,864 Fair Value Measurements as of December 31, 2022 using: Level 1 Level 2 Level 3 Total Cash equivalents: Money market funds $ 60,783 $ — $ — $ 60,783 U.S. Government treasury bills $ — $ 225,730 $ — $ 225,730 Total financial assets $ 60,783 $ 225,730 $ — $ 286,513
Schedule of investments	The following table summarizes the Company’s investments as of September 30, 2023: September 30, 2023 Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Credit Loss Fair Value Assets U.S. Government treasury bills $ 175,144 $ 9 $ — $ — $ 175,153 Total $ 175,144 $ 9 $ — $ — $ 175,153
Schedule of contractual maturity of investments	The following table summarizes the Company’s investments by contractual maturity as of September 30, 2023: September 30, 2023 Amortized Cost Fair Value Due within one year $ 175,144 $ 175,153 Total $ 175,144 $ 175,153

Goodwill and Intangible Assets

Goodwill and Intangible Assets (Tables)	9 Months Ended
	Sep. 30, 2023
Goodwill and Intangible Assets Disclosure [Abstract]
Schedule of intangible assets	Components of the Company's acquired intangible assets are comprised of the following: September 30, 2023 December 31, 2022 Gross carrying amount Accumulated amortization and impairment Net Gross carrying amount Accumulated amortization and impairment Net Discuva platform acquired $ 13,019 $ (13,019) $ — $ 12,900 $ (12,900) $ — Utrophin program acquired — — — 4,015 (4,015) — Option over non-financial asset 824 (824) — 816 (816) — Other licenses 134 (134) — 133 (133) — $ 13,977 $ (13,977) $ — $ 17,864 $ (17,864) $ —

Leases (Tables)

Leases (Tables)	9 Months Ended
	Sep. 30, 2023
Leases [Abstract]
Schedule of lease cost and other information	Lease Cost: Three Months Ended Nine Months Ended 2023 2022 2023 2022 Fixed lease costs $ 678 $ 444 $ 1,535 $ 1,033 Variable lease costs 2 53 71 91 Total lease cost $ 680 $ 497 $ 1,606 $ 1,124 Other information: Nine Months Ended September 30, 2023 Nine Months Ended September 30, 2022 Operating cash flows used for operating leases $ 1,519 $ 891 Weighted average remaining lease term (years) 2.6 3.6 Weighted average discount rate 6.5 % 5.7 %

Promissory Notes Payable to R_2

Promissory Notes Payable to Related Parties (Tables)	9 Months Ended
	Sep. 30, 2023
Related Party Transactions [Abstract]
Schedule of related party debt	Non-current and current debt consisted of the following: Current notes Non-current notes September 30, 2023 December 31, 2022 September 30, 2023 December 31, 2022 Principal amounts $ 100,000 $ 20,000 $ — $ 500,000 Debt discount — (230) — (5,460) Total promissory notes payable to related parties $ 100,000 $ 19,770 $ — $ 494,540
Schedule of estimated future principal payments	As of September 30, 2023, the estimated future principal payments due were as follows: As of September 30, 2023 2023 $ — 2024 100,000 $ 100,000

Stock-Based Compensation and _2

Stock-Based Compensation and Warrants (Tables)	9 Months Ended
	Sep. 30, 2023
Share-Based Payment Arrangement [Abstract]
Schedule of stock option activity	The following table presents the stock option activity for both the 2016 Plan and the 2020 Plan as of September 30, 2023: Nine Months Ended Weighted average exercise price Outstanding at December 31, 2022 19,476,359 $ 3.55 Granted 3,921,450 2.14 Forfeited (2,672,305) 3.98 Exercised (177,237) 2.26 Outstanding at September 30, 2023 20,548,267 $ 3.24 Exercisable at September 30, 2023 5,273,780 $ 5.14
Schedule of stock-based compensation expense	The total stock-based compensation expense included in the Company's condensed consolidated statements of operations and comprehensive loss was as follows: Three Months Ended September 30, Nine Months Ended September 30, 2023 2022 2023 2022 Research and development $ 149 $ 1,162 $ 1,962 $ 3,300 General and administrative 556 1,636 3,393 5,990 Total stock-based compensation expense $ 705 $ 2,798 $ 5,355 $ 9,290

Nature of Business and Operat_2

Nature of Business and Operations and Recent Events (Details) - USD ($) $ / shares in Units, $ in Thousands

9 Months Ended

Oct. 13, 2023

Oct. 12, 2023

Mar. 01, 2023

Feb. 15, 2023

Jan. 19, 2023

Aug. 08, 2022

Sep. 30, 2023

Sep. 30, 2022

Apr. 27, 2023

Jan. 18, 2023

Dec. 31, 2022

Dec. 06, 2022

Subsidiary, Sale of Stock [Line Items]

Proceeds from offering

$ 104,686

$ 100,000

Issuance costs

$ 619

111

Increase to number of authorized shares (in shares)

650,000,000

Common stock, shares authorized (in shares)

1,000,000,000

1,000,000,000

350,000,000

1,000,000,000

Repayment of promissory notes

$ 24,686

$ 25,000

Common stock par value (in dollars per share)

$ 0.01

$ 0.01

$ 0.01

$ 0.01

2020 Stock Incentive Plan | Common Stock | Subsequent event

Subsidiary, Sale of Stock [Line Items]

Increase to number of shares of common stock issuable (in shares)

70,000,000

Chief Operating Officer | Subsequent event

Subsidiary, Sale of Stock [Line Items]

Proceeds from private placement

$ 5,000

Note Purchase Agreement | Chief Executive Officer and Chief Executive Officer and President

Subsidiary, Sale of Stock [Line Items]

Promissory note

$ 520,000

Zanganeh Note | Chief Executive Officer and President

Subsidiary, Sale of Stock [Line Items]

Promissory note

20,000

Repayment of promissory notes

$ 20,000

Duggan February Note | Chief Executive Officer

Subsidiary, Sale of Stock [Line Items]

Promissory note

$ 400,000

Rights offering

Subsidiary, Sale of Stock [Line Items]

Proceeds from offering

$ 500,000

$ 100

Shares issued in transaction (in shares)

476,190,471

103,092,783

Offering price (in dollars per share)

$ 1.05

$ 0.97

Issuance costs

$ 619

$ 111

S-3 Registration Statement | Chief Executive Officer and President

Subsidiary, Sale of Stock [Line Items]

Number of shares registered for resale (in shares)

373,857

S-3 Registration Statement | Chief Executive Officer

Subsidiary, Sale of Stock [Line Items]

Number of shares registered for resale (in shares)

9,346,434

S-3 Registration Statement | Related Party

Subsidiary, Sale of Stock [Line Items]

Number of shares registered for resale (in shares)

10,000,000

Private placement | Chief Operating Officer | Subsequent event

Subsidiary, Sale of Stock [Line Items]

Shares issued in transaction (in shares)

2,976,190

Offering price (in dollars per share)

$ 1.68

Liquidity and Capital Resourc_2

Liquidity and Capital Resources (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022	Dec. 31, 2022
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Net loss	$ 21,268	$ 21,385	$ 578,361	$ 59,553
Net cash flows used in operating activities			57,301	$ 46,773
Accumulated deficit	956,691		956,691		$ 378,330
Cash and cash equivalents	23,792		23,792		348,607
Short-term investments	175,153		175,153		0
Current and long-term research and development tax credits	1,559		1,559
Promissory note payable to a related party	$ 100,000		$ 100,000		$ 19,770

Segment Reporting - Narrative (

Segment Reporting - Narrative (Details)	9 Months Ended
	Sep. 30, 2023 segment country
Segment Reporting [Abstract]
Number of operating segments | segment	1
Number of geographic regions in which the Company operates | country	2

Segment Reporting - Long-lived

Segment Reporting - Long-lived assets by geography (Details) - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022
Revenues from External Customers and Long-Lived Assets [Line Items]
Long-lived assets	$ 6,632	$ 5,081
United Kingdom
Revenues from External Customers and Long-Lived Assets [Line Items]
Long-lived assets	832	2,517
United States
Revenues from External Customers and Long-Lived Assets [Line Items]
Long-lived assets	$ 5,800	$ 2,564

Revenue - Revenue by Category (

Revenue - Revenue by Category (Details) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Revenue from External Customer [Line Items]
Revenue	$ 0	$ 220,000	$ 0	$ 705,000
Licensing agreements
Revenue from External Customer [Line Items]
Revenue	$ 0	$ 220,000	$ 0	$ 705,000

Revenue - Revenue by Geography

Revenue - Revenue by Geography (Details) - 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]
Revenue	$ 0	$ 220	$ 0	$ 705
Latin America
Disaggregation of Revenue [Line Items]
Revenue	$ 0	$ 220	$ 0	$ 705

Revenue - Deferred revenue and

Revenue - Deferred revenue and other income (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Dec. 31, 2022	Dec. 31, 2021
Change in Contract with Customer, Liability [Roll Forward]
Beginning deferred revenue and other income	$ 0	$ 7,939
Additions	0	956
Amount of deferred revenue and other income recognized in the statement of operations	0	(8,479)
Foreign currency adjustments	0	(416)
Ending deferred revenue and other income	0	0
Current deferred revenue and other income	0	0	$ 0	$ 7,939
Long-term deferred revenue and other income	$ 0	$ 0	$ 0	$ 0

Other Operating Income, Net - S

Other Operating Income, Net - Summary by Category (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended		29 Months Ended	64 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Dec. 31, 2022
Revenue from External Customer [Line Items]
Research and development tax credits	$ 265	$ 1,224	$ 768	$ 3,730
Other income	0	0	9	0
Other operating income, net	265	5,462	822	13,283
BARDA
Revenue from External Customer [Line Items]
Funding /Grant income	0	3,889	0	7,774		$ 59,203
CARB-X
Revenue from External Customer [Line Items]
Funding /Grant income	$ 0	$ 349	$ 45	$ 1,779	$ 2,920

Other Operating Income, Net - N

Other Operating Income, Net - Narrative (Details) - USD ($) $ in Thousands	1 Months Ended		3 Months Ended		9 Months Ended		29 Months Ended	64 Months Ended
	May 31, 2021	Sep. 30, 2017	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Dec. 31, 2022
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Current research and development tax credit receivable			$ 812		$ 812		$ 812	$ 5,766
Non-current research and development tax credit receivable			747		747		747	0
BARDA
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Maximum funding value		$ 62,000			72,500
Total committed funding					62,400
Income earned			0	$ 3,889	0	$ 7,774		$ 59,203
CARB-X
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Maximum funding value	$ 4,100
Income earned			$ 0	$ 349	$ 45	$ 1,779	$ 2,920
Funding increase based on achievement of future milestones	$ 3,700

Akeso Collaboration and Licen_2

Akeso Collaboration and License Agreement (Details) - USD ($) $ in Thousands, shares in Millions		1 Months Ended	2 Months Ended	3 Months Ended		9 Months Ended
	Mar. 06, 2023	Jan. 31, 2023	Mar. 06, 2023	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
In-process research and development				$ 0	$ 0	$ 520,915	$ 0
Issuance of common stock in lieu of cash for Akeso upfront payment						$ 45,900
Collaborative arrangement, transaction with party to collaborative arrangement
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Collaborative arrangement, upfront payment			$ 500,000
Cash payment for collaborative arrangement, upfront payment			474,900
Collaborative arrangement, direct transaction costs			$ 115
Collaborative arrangement, additional potential milestone payments		$ 4,500,000
Collaborative arrangement, potential regulatory milestone payments		1,050,000
Collaborative arrangement, potential commercial milestone payments		3,450,000
Collaborative arrangement, transaction with party to collaborative arrangement, upfront payment one
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Cash payment for collaborative arrangement, upfront payment		$ 274,900
Collaborative arrangement, common stock issued in lieu of cash upfront payment (in shares)		10
Collaborative arrangement, upfront payment, paid in shares		$ 25,100
Issuance of common stock in lieu of cash for Akeso upfront payment		$ 45,900
Collaborative arrangement, transaction with party to collaborative arrangement, upfront payment two
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Cash payment for collaborative arrangement, upfront payment	$ 200,000

Other (Expense) Income, Net (De

Other (Expense) Income, Net (Details) - USD ($) $ in Thousands		3 Months Ended		9 Months Ended
	Jan. 17, 2023	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022	Dec. 06, 2022
Other Income and Expenses [Abstract]
Foreign currency gains (losses)		$ (475)	$ (3,799)	$ 344	$ (6,281)
Interest expense on promissory notes payable to related parties		(2,722)	(692)	(13,564)	(1,497)
Interest income		2,485	0	8,028	0
Reclassification of cumulative currency translation gain	$ 419	0	0	419	0
Other expense		(64)	46	(148)	15
Other (expense) income, net		(776)	$ (4,445)	(4,921)	$ (7,763)
Note Purchase Agreement | Chief Executive Officer and Chief Executive Officer and President
Other Income and Expenses [Abstract]
Interest expense on promissory notes payable to related parties		$ (2,722)		$ (13,564)
Related Party Transaction [Line Items]
Promissory note						$ 520,000
Duggan September Note | Chief Executive Officer
Related Party Transaction [Line Items]
Promissory note						$ 100,000

Loss per Share - Computation of

Loss per Share - Computation 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
Earnings Per Share [Abstract]
Net loss	$ (21,268)	$ (21,385)	$ (578,361)	$ (59,553)
Basic weighted average number of shares of common stock outstanding (in shares)	697,739,477	208,909,351	592,366,880	161,846,345
Diluted weighted average number of shares of common stock outstanding (in shares)	697,739,477	208,909,351	592,366,880	161,846,345
Basic net loss per share (in dollars per share)	$ (0.03)	$ (0.10)	$ (0.98)	$ (0.37)
Diluted net loss per share (in dollars per share)	$ (0.03)	$ (0.10)	$ (0.98)	$ (0.37)

Loss per Share - Narrative (Det

Loss per Share - Narrative (Details) - $ / shares	Mar. 01, 2023	Aug. 08, 2022
Subsidiary, Sale of Stock [Line Items]
Share price (in dollars per share)	$ 1.82
Rights offering
Subsidiary, Sale of Stock [Line Items]
Offering price (in dollars per share)	$ 1.05	$ 0.97

Loss per Share - Potentially di

Loss per Share - Potentially dilutive securities excluded from the computation of loss per share (Details) - shares	9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Anti-dilutive shares excluded from diluted earnings per share (in shares)	26,616,761	25,387,813
Options to purchase common stock
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Anti-dilutive shares excluded from diluted earnings per share (in shares)	20,548,267	19,318,301
Warrants
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Anti-dilutive shares excluded from diluted earnings per share (in shares)	5,821,137	5,821,137
Shares expected to be purchased under employee stock purchase plan
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Anti-dilutive shares excluded from diluted earnings per share (in shares)	247,357	248,375

Fair Value Measurements and I_3

Fair Value Measurements and Investments - Assets and liabilities measured at fair value on a recurring basis (Details) - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Short-term investments	$ 175,153
Total financial assets	179,864	$ 286,513
U.S. Government treasury bills
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Short-term investments	175,153
Money market funds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents	4,711	60,783
U.S. Government treasury bills
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents		225,730
Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total financial assets	4,711	60,783
Level 1 | U.S. Government treasury bills
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Short-term investments	0
Level 1 | Money market funds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents	4,711	60,783
Level 1 | U.S. Government treasury bills
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents		0
Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total financial assets	175,153	225,730
Level 2 | U.S. Government treasury bills
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Short-term investments	175,153
Level 2 | Money market funds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents	0	0
Level 2 | U.S. Government treasury bills
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents		225,730
Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total financial assets	0	0
Level 3 | U.S. Government treasury bills
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Short-term investments	0
Level 3 | Money market funds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents	$ 0	0
Level 3 | U.S. Government treasury bills
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents		$ 0

Fair Value Measurements and I_4

Fair Value Measurements and Investments - Narrative (Details) - USD ($)	Sep. 30, 2023	Dec. 31, 2022
Fair Value Disclosures [Abstract]
Cash	$ 19,081,000	$ 62,094,000
Investments		$ 0

Fair Value Measurements and I_5

Fair Value Measurements and Investments - Summary of investments (Details) $ in Thousands	Sep. 30, 2023 USD ($)
Schedule of Held-to-Maturity Securities [Line Items]
Amortized Cost	$ 175,144
Gross Unrealized Gains	9
Gross Unrealized Losses	0
Credit Loss	0
Fair Value	175,153
U.S. Government treasury bills
Schedule of Held-to-Maturity Securities [Line Items]
Amortized Cost	175,144
Gross Unrealized Gains	9
Gross Unrealized Losses	0
Credit Loss	0
Fair Value	$ 175,153

Fair Value Measurements and I_6

Fair Value Measurements and Investments - Contractual maturity of debt securities (Details) $ in Thousands	Sep. 30, 2023 USD ($)
Amortized Cost
Due within one year	$ 175,144
Total	175,144
Fair Value
Due within one year	175,153
Total	$ 175,153

Goodwill and Intangible Asset_2

Goodwill and Intangible Assets - Narrative (Details) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022	Dec. 31, 2022
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill	$ 1,814,000		$ 1,814,000		$ 1,798,000
Cumulative goodwill impairments	0		0
Amortization expense	$ 0	$ 217,000	$ 0	$ 697,000

Goodwill and Intangible Asset_3

Goodwill and Intangible Assets - Schedule of intangible assets (Details) - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	$ 13,977	$ 17,864
Accumulated amortization and impairment	(13,977)	(17,864)
Net	0	0
Software licenses | Discuva platform acquired
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	13,019	12,900
Accumulated amortization and impairment	(13,019)	(12,900)
Net	0	0
Software licenses | Utrophin program acquired
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	0	4,015
Accumulated amortization and impairment	0	(4,015)
Net	0	0
Option over non-financial asset
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	824	816
Accumulated amortization and impairment	(824)	(816)
Net	0	0
Other licenses
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	134	133
Accumulated amortization and impairment	(134)	(133)
Net	$ 0	$ 0

Leases - Narrative (Details)

Leases - Narrative (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Dec. 31, 2022
Lessee, Lease, Description [Line Items]
Additional right-of-use assets recorded	$ 4,245	$ 2,756
Disposal of right-of-use asset	788
Right-of-use assets	6,403		$ 4,175
Menlo Park, California, Expiration May 2026
Lessee, Lease, Description [Line Items]
Additional right-of-use assets recorded	4,245	$ 2,756
Total lease payments	$ 4,701
Lease term	36 months

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
Lease Cost:
Fixed lease costs	$ 678	$ 444	$ 1,535	$ 1,033
Variable lease costs	2	53	71	91
Total lease cost	$ 680	$ 497	$ 1,606	$ 1,124

Leases - Other information (Det

Leases - Other information (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022
Leases [Abstract]
Operating cash flows used for operating leases	$ 1,519	$ 891
Weighted average remaining lease term	2 years 7 months 6 days	3 years 7 months 6 days
Weighted average discount rate	6.50%	5.70%

Promissory Notes Payable to R_3

Promissory Notes Payable to Related Parties - Summary of related party debt (Details) - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022
Current notes
Total promissory notes payable to related parties	$ 100,000	$ 19,770
Non-current notes
Total promissory notes payable to related parties	0	494,540
Promissory Notes | Related Party
Current notes
Principal amounts	100,000	20,000
Debt discount	0	(230)
Total promissory notes payable to related parties	100,000	19,770
Non-current notes
Principal amounts	0	500,000
Debt discount	0	(5,460)
Total promissory notes payable to related parties	$ 0	$ 494,540

Promissory Notes Payable to R_4

Promissory Notes Payable to Related Parties - Narrative (Details)				3 Months Ended		9 Months Ended
	Feb. 15, 2023 USD ($)	Jan. 19, 2023 USD ($) promissory_note	Dec. 06, 2022 USD ($) $ / shares shares	Sep. 30, 2023 USD ($) $ / shares	Sep. 30, 2022 USD ($)	Sep. 30, 2023 USD ($) $ / shares	Sep. 30, 2022 USD ($)	Apr. 27, 2023 $ / shares	Dec. 31, 2022 USD ($) $ / shares
Related Party Transaction [Line Items]
Repayment of promissory notes						$ 24,686,000	$ 25,000,000
Common stock par value (in dollars per share) | $ / shares			$ 0.01	$ 0.01		$ 0.01		$ 0.01	$ 0.01
Interest expense				$ 2,722,000	$ 692,000	$ 13,564,000	$ 1,497,000
Chief Executive Officer and Chief Executive Officer and President | Note Purchase Agreement
Related Party Transaction [Line Items]
Promissory note			$ 520,000,000
Interest rate			7.50%
Prepaid interest, conversion amount (in dollars per share) | $ / shares			$ 0.7913
Prepaid interest, conversion amount base (in dollars per share) | $ / shares			$ 0.01
Common stock issued for prepaid interest (in shares) | shares			9,720,291
Debt issuance costs			$ 44,000
Interest expense				2,722,000		13,564,000
Amortized imputed interest						761,000
Accrued interest				$ 0		$ 0			$ 0
Chief Executive Officer and Chief Executive Officer and President | Note Purchase Agreement | Variable rate, three months immediately following February 15, 2023 | Prime rate
Related Party Transaction [Line Items]
Interest rate margin			0.50%
Chief Executive Officer and Chief Executive Officer and President | Note Purchase Agreement | Variable rate, thereafter | Prime rate
Related Party Transaction [Line Items]
Interest rate margin			3%
Chief Executive Officer and Chief Executive Officer and President | Duggan February Note and Zanganeh Note
Related Party Transaction [Line Items]
Period from public offering			5 days
Public offering proceeds threshold percentage			100%
Chief Executive Officer | Duggan Promissory Notes
Related Party Transaction [Line Items]
Promissory note, prepayment triggering event, public offering proceeds threshold		$ 500,000,000
New note issuances | promissory_note		2
Chief Executive Officer | Duggan February Note
Related Party Transaction [Line Items]
Promissory note			$ 400,000,000
Effective interest rate				8.90%		8.90%
Chief Executive Officer | Duggan September Note
Related Party Transaction [Line Items]
Promissory note			100,000,000
Effective interest rate				11.20%		11.20%
Chief Executive Officer and President | Zanganeh Note
Related Party Transaction [Line Items]
Promissory note			$ 20,000,000
Repayment of promissory notes	$ 20,000,000
Effective interest rate				8.90%		8.90%

Promissory Notes Payable to R_5

Promissory Notes Payable to Related Parties - Estimated future principal payments (Details) - Promissory Notes - Related Party $ in Thousands	Sep. 30, 2023 USD ($)
Related Party Transaction [Line Items]
2023	$ 0
2024	100,000
Principal amounts payable to related parties	$ 100,000

Stock-Based Compensation and _3

Stock-Based Compensation and Warrants - Narrative (Details) - USD ($) $ / shares in Units, $ in Thousands	Oct. 12, 2023	Sep. 30, 2023	Dec. 31, 2022
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Aggregate intrinsic value, outstanding options		$ 5,683
Aggregate intrinsic value, exercisable options		$ 280
Warrants
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Non-option equity instruments outstanding (in shares)		5,821,137	5,821,137
Non-option equity instruments exercisable (in shares)		5,821,137	5,821,137
Weighted average exercise price of non-option equity instruments outstanding (in dollars per share)		$ 1.56	$ 1.56
Weighted average exercise price of non-option equity instruments exercisable (in dollars per share)		$ 1.56	$ 1.56
2020 Stock Incentive Plan | Common Stock | Subsequent event
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Increase to number of shares of common stock issuable (in shares)	70,000,000

Stock-Based Compensation and _4

Stock-Based Compensation and Warrants - Stock Option Activity (Details)	9 Months Ended
	Sep. 30, 2023 $ / shares shares
Number of share options
Beginning balance (in shares) | shares	19,476,359
Granted (in shares) | shares	3,921,450
Forfeited (in shares) | shares	(2,672,305)
Exercise (in shares) | shares	(177,237)
Ending balance (in shares) | shares	20,548,267
Weighted average exercise price
Beginning balance (in dollars per share) | $ / shares	$ 3.55
Granted (in dollars per share) | $ / shares	2.14
Forfeited (in dollars per share) | $ / shares	3.98
Exercised (in dollars per share) | $ / shares	2.26
Ending balance (in dollars per share) | $ / shares	$ 3.24
Stock option activity, additional disclosures
Number of share options, exercisable (in shares) | shares	5,273,780
Weighted average exercise price, exercisable (in dollars per share) | $ / shares	$ 5.14

Stock-Based Compensation and _5

Stock-Based Compensation and Warrants - Stock-Based Compensation Expense (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Stock-based compensation expense	$ 705	$ 2,798	$ 5,355	$ 9,290
Research and development
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Stock-based compensation expense	149	1,162	1,962	3,300
General and administrative
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Stock-based compensation expense	$ 556	$ 1,636	$ 3,393	$ 5,990

Related Party Transactions (Det

Related Party Transactions (Details) $ / shares in Units, $ in Thousands

3 Months Ended

9 Months Ended

Oct. 13, 2023 USD ($) $ / shares shares

Mar. 01, 2023 USD ($) $ / shares shares

Feb. 15, 2023 USD ($)

Jan. 19, 2023 USD ($) promissory_note

Dec. 06, 2022 USD ($) $ / shares shares

Aug. 08, 2022 USD ($) $ / shares shares

Jun. 30, 2022

Mar. 10, 2022 USD ($)

Sep. 30, 2023 USD ($) $ / shares

Sep. 30, 2022 USD ($)

Sep. 30, 2023 USD ($) $ / shares

Sep. 30, 2022 USD ($)

Apr. 27, 2023 $ / shares shares

Dec. 31, 2022 $ / shares

Jul. 29, 2022 ft²

Jul. 25, 2022 ft²

Related Party Transaction [Line Items]

Proceeds from related party promissory notes

$ 0

$ 25,000

Proceeds from offering

104,686

100,000

Issuance costs

619

111

Repayment of promissory notes

24,686

25,000

Interest paid

$ 7,711

434

Common stock par value (in dollars per share) | $ / shares

$ 0.01

$ 0.01

$ 0.01

$ 0.01

$ 0.01

Rights offering

Related Party Transaction [Line Items]

Proceeds from offering

$ 500,000

$ 100

Shares issued in transaction (in shares) | shares

476,190,471

103,092,783

Offering price (in dollars per share) | $ / shares

$ 1.05

$ 0.97

Issuance costs

$ 619

$ 111

Issuance of common stock

$ 395,314

0

Affiliated entity | First Amendment to Sublease Agreement

Related Party Transaction [Line Items]

Area of premises subleased | ft²

4,500

Sublease extension term

39 months

Payments to related party

$ 189

567

Affiliated entity | Second Amendment to Sublease Agreement

Related Party Transaction [Line Items]

Area of premises subleased | ft²

1,277

Payments to related party

55

163

Affiliated entity | Sublease Agreement

Related Party Transaction [Line Items]

Payments to related party

$ 179

$ 537

Chief Executive Officer and Chief Executive Officer and President | Note Purchase Agreement

Related Party Transaction [Line Items]

Promissory note

$ 520,000

Interest rate

7.50%

Prepaid interest, conversion amount (in dollars per share) | $ / shares

$ 0.7913

Prepaid interest, conversion amount base (in dollars per share) | $ / shares

$ 0.01

Common stock issued for prepaid interest (in shares) | shares

9,720,291

Interest paid

$ 2,917

$ 7,711

Chief Executive Officer and Chief Executive Officer and President | Note Purchase Agreement | Prime rate | Variable rate, three months immediately following February 15, 2023

Related Party Transaction [Line Items]

Interest rate margin

0.50%

Chief Executive Officer and Chief Executive Officer and President | Note Purchase Agreement | Prime rate | Variable rate, thereafter

Related Party Transaction [Line Items]

Interest rate margin

3%

Chief Executive Officer and Chief Executive Officer and President | Duggan February Note and Zanganeh Note

Related Party Transaction [Line Items]

Period from public offering

5 days

Public offering proceeds threshold percentage

100%

Chief Executive Officer | Rights offering

Related Party Transaction [Line Items]

Issuance of common stock

$ 395,314

Chief Executive Officer | S-3 Registration Statement

Related Party Transaction [Line Items]

Number of shares registered for resale (in shares) | shares

9,346,434

Chief Executive Officer | March 2022 Note

Related Party Transaction [Line Items]

Proceeds from related party promissory notes

$ 25,000

Promissory note

$ 25,000

Interest rate

4.75%

3.25%

Promissory note, prepayment triggering event, public offering proceeds threshold

$ 25,000

Notes payable, maximum term

18 months

Chief Executive Officer | Duggan Promissory Notes

Related Party Transaction [Line Items]

Promissory note, prepayment triggering event, public offering proceeds threshold

$ 500,000

New note issuances | promissory_note

2

Chief Executive Officer | Duggan February Note

Related Party Transaction [Line Items]

Promissory note

$ 400,000

Chief Executive Officer | Duggan September Note

Related Party Transaction [Line Items]

Promissory note

100,000

Chief Executive Officer and President | S-3 Registration Statement

Related Party Transaction [Line Items]

Number of shares registered for resale (in shares) | shares

373,857

Chief Executive Officer and President | Zanganeh Note

Related Party Transaction [Line Items]

Promissory note

$ 20,000

Repayment of promissory notes

$ 20,000

Related Party | S-3 Registration Statement

Related Party Transaction [Line Items]

Number of shares registered for resale (in shares) | shares

10,000,000

Chief Operating Officer | Subsequent event

Related Party Transaction [Line Items]

Proceeds from private placement

$ 5,000

Chief Operating Officer | Private placement | Subsequent event

Related Party Transaction [Line Items]

Shares issued in transaction (in shares) | shares

2,976,190

Offering price (in dollars per share) | $ / shares

$ 1.68

Commitment and Contingencies (D

Commitment and Contingencies (Details) - USD ($)	Sep. 30, 2023	Dec. 31, 2022
Commitments and Contingencies Disclosure [Abstract]
Capital commitments	$ 0	$ 0
Non-cancellable purchase commitments	$ 6,356,000

Subsequent Events (Details)

Subsequent Events (Details) - Subsequent event - Chief Operating Officer $ / shares in Units, $ in Thousands	Oct. 13, 2023 USD ($) $ / shares shares
Subsequent Event [Line Items]
Proceeds from private placement | $	$ 5,000
Private placement
Subsequent Event [Line Items]
Offering price (in dollars per share) | $ / shares	$ 1.68
Shares issued in transaction (in shares) | shares	2,976,190