Ambrx Biopharma (AMAM) 10-K 30 Mar 23 2022 FY Annual report Financial data

Cover Page

Cover Page - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2022	Mar. 24, 2023	Jun. 30, 2022
Document Information [Line Items]
Document Type	10-K
Entity Registrant Name	Ambrx Biopharma Inc.
Amendment Flag	false
Document Period End Date	Dec. 31, 2022
Document Fiscal Year Focus	2022
Document Fiscal Period Focus	FY
Current Fiscal Year End Date	--12-31
Securities Act File Number	001-40505
Entity Central Index Key	0001836056
Entity Incorporation, State or Country Code	E9
Document Annual Report	true
Document Transition Report	false
Entity Ex Transition Period	true
Entity Well-known Seasoned Issuer	No
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Non-accelerated Filer
Entity Small Business	true
Entity Emerging Growth Company	true
ICFR Auditor Attestation Flag	false
Entity Tax Identification Number	00-0000000
Entity Shell Company	false
Auditor Name	Deloitte & Touche LLP
Auditor Firm ID	34
Auditor Location	San Diego, California, United States
Entity Address, Address Line One	10975 North Torrey Pines Road
Entity Address, City or Town	La Jolla
Entity Address, State or Province	CA
Entity Address, Postal Zip Code	92037
Entity Address, Country	US
City Area Code	858
Local Phone Number	875-2400
Entity Common Stock, Shares Outstanding		386,486,014
Entity Public Float			$ 75.9
Documents Incorporated by Reference [Text Block]	DOCUMENTS INCORPORATED BY REFERENCE As noted herein, the information called for by Part III of this Annual Report on Form 10-K is incorporated by reference to specified portions of the registrant’s definitive proxy statement to be filed in conjunction with the registrant’s 2023 Annual Meeting of Shareholders, which is expected to be filed not later than 120 days after the registrant's fiscal year ended December 31, 2022 .
American Depositary Shares [Member]
Document Information [Line Items]
Title of 12(b) Security	American Depositary Shares (ADSs), each representing seven ordinary shares, par value $0.0001 per ordinary share
Trading Symbol	AMAM
Security Exchange Name	NASDAQ
Ordinary Shares [Member]
Document Information [Line Items]
Title of 12(b) Security	Ordinary shares, par value $0.0001 per share
Security Exchange Name	NASDAQ
No Trading Symbol Flag	true

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Current assets:
Cash and cash equivalents	$ 55,610	$ 170,064
Restricted cash	831	842
Marketable debt securities, available-for-sale	28,873	0
Accounts receivable, net	376	1,239
Prepaid expenses and other current assets	4,893	4,661
Total current assets	90,583	176,806
Marketable debt securities, available-for-sale, net of current portion	16,793	0
Property and equipment, net	3,044	2,984
Right-of-use assets, net	10,968	12,737
Intangible assets, net	25,250	35,962
Other long-term assets	339	530
Total assets	146,977	229,019
Current liabilities:
Accounts payable	3,205	5,272
Accrued liabilities	11,314	14,125
Operating lease liabilities, current portion	1,734	915
Deferred revenue, current portion	407	4,267
Total current liabilities	16,660	24,579
Operating lease liabilities, net of current portion	10,245	12,212
Deferred tax liabilities	880	880
Deferred revenue, net of current portion	1,342	1,381
Total liabilities	29,127	39,052
Commitments and contingencies (Note 7)
Shareholders' Equity (Deficit):
Ordinary Shares, par value $0.0001; 500,000,000 shares authorized at December 31, 2022 and 2021; 270,455,232 and 270,120,548 shares issued and outstanding as of December 31, 2022 and 2021, respectively	27	27
Additional paid-in capital	410,753	404,362
Accumulated other comprehensive loss	(1,302)	(790)
Accumulated deficit	(291,628)	(213,632)
Total shareholders' equity (deficit)	117,850	189,967
Total liabilities and shareholders' equity	$ 146,977	$ 229,019

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - $ / shares	Dec. 31, 2022	Dec. 31, 2021
Common Stock, Par or Stated Value Per Share	$ 0.0001	$ 0.0001
Common Stock, Shares Authorized	500,000,000	500,000,000
Common Stock, Shares, Issued	270,455,232	270,120,548
Common Stock, Shares, Outstanding	270,455,232	270,120,548
Series A Convertible Preferred Stock [Member]
Temporary Equity, Shares Outstanding		0
Series B Convertible Preferred Stock [Member]
Temporary Equity, Shares Outstanding		0

Consolidated Statements of Oper

Consolidated Statements of Operations and comprehensive Loss - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Revenues	$ 7,402	$ 7,455
Operating expenses:
Research and development	53,307	54,295
General and administrative	20,836	17,071
Impairment of intangible assets	9,660	513
Total operating expenses	83,803	71,879
Loss from operations	(76,401)	(64,424)
Other income (expense), net:
Investment income, net	1,337	0
Interest expense, net	(968)	0
Other (expense) income, net	(27)	40
Change in fair value of redeemable noncontrolling interests	0	(3,903)
Total other income (expense), net	342	(3,863)
Loss before income taxes	(76,059)	(68,287)
Provision for income taxes	(1,937)	(1)
Net loss	(77,996)	(68,288)
Less: Net loss attributable to the redeemable noncontrolling interests	0	209
Net loss attributable to Ambrx Biopharma Inc. shareholders	$ (77,996)	$ (68,079)
Net loss per share applicable to Ambrx Biopharma Inc. ordinary shareholders-basic	$ (0.29)	$ (0.48)
Net loss per share applicable to Ambrx Biopharma Inc. ordinary shareholders-diluted	$ (0.29)	$ (0.48)
Weighted-average ordinary shares used to compute net loss per share attributable to ordinary shareholders, basic	270,241,698	143,175,224
Weighted-average ordinary shares used to compute net loss per share attributable to ordinary shareholders, diluted	270,241,698	143,175,224
Other comprehensive loss, net of tax:
Net loss	$ (77,996)	$ (68,288)
Foreign currency translation adjustment	0	(18)
Unrealized loss on marketable debt securities, available-for-sale	(512)	0
Total other comprehensive loss	(512)	(18)
Comprehensive loss	(78,508)	(68,306)
Less: Comprehensive loss attributable to the redeemable noncontrolling interests		208
Comprehensive loss attributable to Ambrx Biopharma Inc.	$ (78,508)	$ (68,098)

Consolidated Statements of Chan

Consolidated Statements of Changes in Redeemable Noncontrolling Interests, Convertible Preferred Shares And Shareholders' Equity (Deficit) - USD ($) $ in Thousands	Total	Redeemable Noncontrolling Interests [Member]	Series A Convertible Preferred Stock [Member]	Series B Convertible Preferred Stock [Member]	Ordinary Shares [Member]	Additional Paid-In-Capital [Member]	Accumulated Other Comprehensive Loss [Member]	Accumulated Deficit [Member]	IPO [Member]	IPO [Member] Ordinary Shares [Member]	IPO [Member] Additional Paid-In-Capital [Member]	Over-Allotment Option [Member]	Over-Allotment Option [Member] Ordinary Shares [Member]	Over-Allotment Option [Member] Additional Paid-In-Capital [Member]
Beginning balance ( in preferred shares value) at Dec. 31, 2020		$ 1,287	$ 157,689	$ 95,342
Beginning balance (in preferred shares) at Dec. 31, 2020			135,936,550	57,575,008
Conversion of preferred stock into ordinary shares upon closing of initial public offering (in preferred shares value)			$ (157,689)	$ (95,342)
Conversion of preferred stock into ordinary shares upon closing of initial public offering (in preferred shares)			(135,936,550)	(57,575,008)
Accretion of redeemable noncontrolling interests to fair value (in preferred shares value)	$ 42,324	42,324
Reclassify NCI to current liability (in preferred shares value)		(43,403)
Foreign currency translation adjustments (in preferred shares value)		1
Net loss (in preferred shares value)	(209)	(209)
Ending balance (in preferred shares value) at Dec. 31, 2021		$ 0	$ 0	$ 0
Ending balance (in preferred shares) at Dec. 31, 2021			0	0
Beginning balance at Dec. 31, 2020	(139,434)					$ 6,805	$ (686)	$ (145,553)
Beginning balance (in shares) at Dec. 31, 2020					170,000
Share-based compensation	11,856					11,856
Conversion of preferred stock into ordinary shares	253,031				$ 19	253,012
Conversion of preferred stock into ordinary shares (in shares)					193,511,558
Issuance of ordinary shares for cash	20,495				$ 2	20,493			$ 113,154	$ 5	$ 113,149
Issuance of ordinary shares for cash (in shares)					21,189,173					49,000,000
Issuance of ordinary shares upon exercise of options												$ 14,947	$ 1	$ 14,946
Issuance of ordinary shares upon exercise of options (in shares)													6,249,817
Unrealized losses on marketable debt securities, available-for-sale	0
Accretion of redeemable noncontrolling interests to fair value	(42,324)					(42,324)
Settlement of redeemable noncontrolling interests	85					85	(85)
Reclassify freestanding forward sale contract upon settlement of redeemable noncontrolling interests	26,340					26,340
Foreign currency translation adjustments	(19)						(19)
Net loss	(68,079)							(68,079)
Ending balance at Dec. 31, 2021	189,967				$ 27	404,362	(790)	(213,632)
Ending balance (in shares) at Dec. 31, 2021					270,120,548
Accretion of redeemable noncontrolling interests to fair value (in preferred shares value)	0
Net loss (in preferred shares value)	0
Share-based compensation	6,253					6,253
Issuance of ordinary shares for cash	138					138
Issuance of ordinary shares for cash (in shares)					334,684
Unrealized losses on marketable debt securities, available-for-sale	(512)						(512)
Settlement of redeemable noncontrolling interests	0
Net loss	(77,996)							(77,996)
Ending balance at Dec. 31, 2022	$ 117,850				$ 27	$ 410,753	$ (1,302)	$ (291,628)
Ending balance (in shares) at Dec. 31, 2022					270,455,232

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Cash flows from operating activities:
Net loss	$ (77,996)	$ (68,288)
Noncash adjustments reconciling net loss to cash flows from operating activities:
Loss on impairment of intangible assets	9,660	513
Share-based compensation expense	6,253	11,856
Noncash lease expense	2,730	1,582
Amortization of intangible assets	1,052	1,604
Depreciation and amortization	751	550
Loss on disposal of property and equipment	6	0
Accretion/amortization of investment securities, net	(510)	0
Change in fair value of redeemable noncontrolling interests	0	3,903
Changes in operating assets and liabilities:
Accounts receivable, net	863	(811)
Prepaid and other current assets and other long-term assets	(41)	(2,629)
Accounts payable	(1,829)	2,403
Accrued liabilities	(3,605)	10,502
Deferred revenue	(3,899)	(4,083)
Operating lease liabilities	(2,110)	(1,742)
Net cash used in operating activities	(68,675)	(44,640)
Cash flows from investing activities:
Purchases of marketable debt securities, available-for-sale	(84,852)	0
Sales of marketable debt securities, available-for-sale	2,188	0
Proceeds from Sale and Maturity of Marketable Securities	37,000	0
Purchases of property and equipment	(1,054)	(1,956)
Acquisition of intangible assets	0	(1,250)
Net cash used in investing activities	(46,718)	(3,206)
Cash flows from financing activities:
Proceeds from short-term bridge loan	166,000	0
Repayment of short-term bridge loan	(166,000)	0
Proceeds from directors and officers insurance premium financing agreement	1,831	0
Payments of directors and officers insurance premium financing agreement	(905)	0
Proceeds from issuance of ordinary shares, net of issuance costs	138	148,732
Payments to acquire the Ambrx Shanghai noncontrolling interests	0	(20,966)
Payments of costs for the issuance of Series B preferred shares	0	(339)
Payments of costs for the issuance of ordinary shares	(136)	0
Net cash provided by financing activities	928	127,427
Effect of exchange rate changes on cash, cash equivalents and restricted cash	0	47
Net (decrease) increase in cash, cash equivalents and restricted cash	(114,465)	79,628
Cash, cash equivalents and restricted cash, beginning of period	170,906	91,278
Cash, cash equivalents and restricted cash, end of period	56,441	170,906
Supplemental information:
Cash paid for interest	963	0
Cash paid for income taxes	319	1
Noncash investing and financing activities:
Property and equipment costs in accounts payable and accrued liabilities	491	727
ROU assets and lease liabilities obtain through reassessment of an existing lease	0	11,455
Conversion of convertible preferred shares into ordinary shares	0	253,031
Reclassification of redeemable noncontrolling interests from temporary equity to current liabilities	0	43,403
Accretion of redeemable noncontrolling interests to fair value	0	42,324
Deferred initial public offering costs in accounts payable and accrued liabilities	0	136
Reclassification of accumulated other comprehensive loss upon settlement of redeemable noncontrolling interests	$ 0	$ 85

Description of Business and Bas

Description of Business and Basis of Presentation	12 Months Ended
	Dec. 31, 2022
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Description of Business and Basis of Presentation	1. Description of Business and Basis of Presentation Description of Business Ambrx Biopharma Inc. (Ambrx or the Company) is a clinical-stage biologics company focused on discovering and developing a novel class of engineered precision biologics using its proprietary expanded genetic code technology platform that allows it to incorporate, in a site-specific manner, synthetic amino acids into proteins within living cells. Ambrx commenced its operations in the United States in January 2003 when Ambrx Inc. (Ambrx US), was incorporated in Delaware. In May 2015, Ambrx incorporated under the laws of the Cayman Islands and has become the ultimate holding company (Ambrx Cayman) through a series of transactions. As of the date of these consolidated financial statements, the Company owned 100 % of Shanghai Ambrx Biopharma Company Limited (Ambrx Shanghai) (see Reorganization discussion below) and Biolaxy Pharmaceutical Hong Kong Limited, a company incorporated in Hong Kong (Ambrx HK). Ambrx HK owned 100 % of Ambrx US, and Ambrx US owned 100 % of Ambrx Australia Pty Limited, a company incorporated in Australia (Ambrx AU). Ambrx US is based in San Diego, California. Prior to Ambrx Shanghai becoming a wholly owned subsidiary (see Reorganization discussion below), the Company had recognized redeemable noncontrolling interests in its consolidated financial statements for the 11 % it did not directly own. As of June 30, 2021, the Company no longer recognizes redeemable noncontrolling interests in its consolidated financial statements. Reorganization During the second quarter of 2021, the Company completed a reorganization of its corporate structure (the Reorganization). The Reorganization primarily related to the Company’s redeemable noncontrolling interests (RNCI), which represented the approximately 11 % equity interest in the Company’s subsidiary, Ambrx Shanghai, that was not attributable, either directly or indirectly, to the Company, and was recognized separately from the Company’s controlling interest within its consolidated financial statements. In April 2021, the Company purchased all outstanding shares of Ambrx HK from Ambrx Shanghai for an aggregate purchase price of $ 190.0 million, through the issuance of a promissory note to Ambrx Shanghai by Ambrx for the purchase price. As a result of these common control transactions, Ambrx Shanghai and Ambrx HK both became wholly owned subsidiaries of Ambrx in April 2021. This promissory note was settled in the first quarter of 2022, through the payment of $ 24.0 million in cash by Ambrx to Ambrx Shanghai and a capital reduction in Ambrx Shanghai of $ 166.0 million (the Capital Reduction). To effect the Capital Reduction in Ambrx Shanghai and to comply with regulatory requirements in the People’s Republic of China, the Company borrowed $ 166.0 million in the form of a short-term bridge loan from a financial institution incurring approximately $ 1.0 million in fees and interest and repaid the loan with the proceeds from the Capital Reduction. In connection with the Reorganization, the Company and the approximately 11 % minority shareholders of Ambrx Shanghai (the Shanghai Shareholders) signed the Reorganization agreements dated March 23, 2021, as amended in April 2021. During the second quarter of 2021, in accordance with the Reorganization agreements, the Company (a) paid the Shanghai Shareholders an aggregate of approximately $ 21.0 million for the purchase of the RNCI, and (b) sold to certain of the Shanghai Shareholders an aggregate of 2,004,879 ordinary shares for aggregate gross proceeds of approximately $ 2.1 million. Prior to the execution of the Reorganization agreements, the Company’s RNCI was classified outside of permanent equity because, upon certain contingent events that were not solely within the Company’s control, it may have been required to purchase the RNCI. Through December 31, 2020, the Company did not adjust the carrying value of the RNCI to its redemption value since a certain contingent event was not probable of occurrence. Through March 31, 2021, revenues, expenses, gains, losses, net loss and other comprehensive loss were reported in the financial statements at the consolidated amounts, which included the amounts attributable to both the controlling and redeemable noncontrolling interests. Upon execution of the Reorganization agreements, the Company’s RNCI became mandatorily redeemable as the Company became contractually obligated to purchase the RNCI. Therefore, the Company reclassified the RNCI from outside of permanent equity to a current liability upon which the RNCI was no longer subject to allocation of losses or other comprehensive losses. The Company identified two forward contracts embedded within the RNCI (the Forward Contracts). The first forward contract is the forward purchase contract for the Company to purchase all the RNCI from the Shanghai Shareholders for a fixed price of $ 36.7 million (the Forward Purchase Contract), and the second forward contract is the forward sale contract for the Company to sell a fixed number of ordinary shares to the Shanghai Shareholders for a fixed price of $ 36.0 million (the Forward Sale Contract). The Forward Contracts were determined to be embedded in the Company’s RNCI (the Combined RNCI). Upon the execution of the Reorganization agreements, the Combined RNCI was reclassified from temporary equity to a current liability at fair value of $ 43.4 million in the Company’s consolidated balance sheets. The initial fair value of the Combined RNCI was determined using level three inputs of the fair value hierarchy including equity value of the Company determined using combinations of income and market approaches and estimated expiration term. Subsequent changes in fair value of the Combined RNCI were recorded as a component of other income (expense), net, in the consolidated statements of operations and comprehensive loss until the liability was fully settled in June 2021. In April 2021, the Company and the Shanghai Shareholders amended the Reorganization agreements to reduce the purchase price of both the Forward Purchase Contract and the Forward Sale Contract by $ 15.7 million (the Amendment). The Amendment resulted in a $ 0.3 million decrease in the fair value of the Combined RNCI liability. During the year ended December 31, 2021, the Company recorded a $ 3.9 million loss due to a changes in fair value associated with the Combined RNCI. Upon the $ 21.0 million cash settlement of the RNCI during the second quarter of 2021, the Forward Sale Contract was determined to meet the scope exception in ASC 815‑10 – Derivatives and Hedging for equity classification and was determined to be an equity classified freestanding financial instrument in accordance with ASC Topic 480, Distinguishing Liabilities from Equity . Accordingly, the Company reclassified the fair value associated with the Forward Sale Contract of $ 26.3 million to additional paid-in-capital in the consolidated balance sheets. Initial Public Offering In June 2021, the Company completed its initial public offering (the IPO) of 7,000,000 American Depositary Shares (ADSs) at an offering price of $ 18.00 per ADS. Each ADS represents seven ordinary shares of the Company. Net proceeds from the IPO were approximately $ 113.2 million, net of underwriting discounts and commissions of $ 8.8 million and offering-related transaction costs, including direct legal, accounting and other professional fees incurred of approximately $ 4.0 million. In connection with the IPO, the Company’s outstanding convertible preferred shares were automatically converted into 193,511,558 ordinary shares and were reclassified into permanent shareholders’ equity. Following the IPO, there were no convertible preferred shares outstanding. In July 2021, the underwriters exercised their overallotment option to purchase 892,831 ADSs at the initial offering price of $ 18.00 per ADS for net proceeds to the Company of $ 14.9 million after underwriting discounts and commissions. Basis of Presentation and Principles of Consolidation The accompanying consolidated financial statements have been prepared in accordance with accounting principles generally accepted in the United States of America (U.S. GAAP). The Company’s consolidated financial statements include the accounts of the Company and its wholly owned subsidiaries. Intercompany accounts and transactions have been eliminated in consolidation. The Company’s operating currency is the U.S. dollar. Prior to June 30, 2021, in general, the functional currency of the Company’s subsidiaries was the U.S. dollar; however, for Ambrx Shanghai the functional currency was the local currency. Consequently, through June 30, 2021, assets and liabilities for Ambrx Shanghai were translated into U.S. dollars, and the effects of foreign currency translation adjustments were included as a component of accumulated other comprehensive loss within the Company’s consolidated statements of changes in redeemable noncontrolling interests, convertible preferred shares and shareholders’ (deficit) equity. Effective July 1, 2021, the functional currency for all the Company’s subsidiaries is the U.S. dollar. As such, the Company no longer recognizes currency translation adjustments as a component of accumulated other comprehensive loss, rather all adjustments are recorded in other income (expense), net, in the consolidated statements of operations and comprehensive loss. Liquidity and Capital Resources The Company has incurred net operating losses and negative cash flows from operations since its incorporation in 2015 and had an accumulated deficit of $ 291.6 million as of December 31, 2022. As of December 31, 2022, the Company had cash, cash equivalents and marketable debt securities, available-for-sale (MDS) of $ 101.3 million, of which $ 16.8 million are non-current MDS. Management believes its existing financial resources are sufficient to continue operating activities for at least 12 months past the issuance date of these consolidated financial statements. Future capital requirements will depend on many factors, including the timing and extent of spending on research and development (R&D) activities and market acceptance of the Company’s products, if approved. Until such time the Company can generate significant revenue from product sales, if ever, the Company expects to finance its operations through public or private equity or debt financings or other capital sources, which may include strategic collaborations or other arrangements with third parties. However, the Company may be unable to raise additional funds or enter into such other agreements or arrangements when needed on favorable terms, or at all. If the Company is unable to raise capital or enter into such agreements as and when needed, the Company may have to significantly delay, scale back or discontinue the development or commercialization of one or more of its product candidates. Insufficient liquidity may also require the Company to relinquish rights to product candidates at an earlier stage of development or on less favorable terms than the Company would otherwise choose. The Company’s ability to raise additional funds may be adversely impacted by potential worsening global macroeconomic and geopolitical conditions and disruptions to, and volatility in, the credit and financial markets in the United States and worldwide, including from the ongoing COVID-19 pandemic and related variants, the ongoing conflict between Ukraine and Russia and recent disruption in access to bank deposits and lending commitments due to bank failures.

Summary of Significant Accounti

Summary of Significant Accounting Policies	12 Months Ended
	Dec. 31, 2022
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	2. Summary of Significant Accounting Policies Use of Estimates The preparation of consolidated financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the consolidated financial statements and the reported amounts of revenues and expenses during the reporting period. On an ongoing basis, the Company evaluates its estimates, including those related to the valuation of share-based awards, MDS, and other fair value measurements, the discount rate used in estimating the present value of the right-of-use (ROU) assets and lease liabilities, the useful lives of property and equipment and intangible assets, the recoverability of long-lived assets, clinical trial accruals, periods over which revenue should be recognized, deferred income taxes and related valuation allowances, and the assessment of the Company’s ability to fund its operations for at least the next 12 months from the date of issuance of these consolidated financial statements. The Company bases its estimates on historical experience and other market-specific or other relevant assumptions that it believes to be reasonable under the circumstances. Estimates are assessed each reporting period and updated to reflect current information. As future events and their effects cannot be determined with precision, actual results may materially differ from those estimates or assumptions. Due to the recent disruption in access to bank deposits and lending commitments due to bank failures, the COVID-19 pandemic and macroeconomic and geopolitical conditions, there has been uncertainty and disruption in the global economy and financial markets. The Company is not aware of any specific event or circumstance that would require an update to its estimates or judgments or a revision of the carrying value of its assets or liabilities as of December 31, 2022. While there was no material impact to the Company’s consolidated financial statements as of and for the year ended December 31, 2022, these estimates may change, as new events occur and additional information is obtained, which could materially impact the Company’s consolidated financial statements in future reporting periods. Segment Reporting Operating segments are identified as components of an enterprise about which separate discrete financial information is available for evaluation by the chief operating decision-maker, who is the Chief Executive Officer of the Company, in making decisions regarding resource allocation and assessing performance. The Company views its operations and manages its business in one operating segment. Risk and Uncertainties Since December 2019, COVID-19, a novel strain of coronavirus has become a global pandemic. The virus continues to spread globally, has been declared a pandemic by the World Health Organization and has spread to over 100 countries, including the United States. The impact of this pandemic has been and will likely continue to be extensive in many aspects of society, which has resulted in and will likely continue to result in significant disruptions to the global economy, as well as businesses and capital markets around the world. The full extent to which the COVID-19 pandemic will directly or indirectly impact the Company’s business, results of operations and financial condition, including expenses, clinical trials and other costs, will depend on future developments that are highly uncertain, including as a result of new information that may emerge concerning COVID-19 and the actions taken to contain or treat COVID-19, as well as the economic impact on local, regional, national and international markets. Concentrations of Credit Risk Financial instruments that potentially subject the Company to significant concentrations of credit risk consist primarily of cash and cash equivalents, restricted cash, MDS, and accounts receivable which are generally not collateralized. Deposits in the Company’s checking and money market accounts are maintained in federally insured financial institutions and are subject to federally insured limits or limits set by the Securities Investor Protection Corporation. In addition, the Company maintains cash and cash equivalents in foreign bank accounts, which are not federally insured. The Company attempts to minimize credit risk associated with its cash and cash equivalents by periodically evaluating the credit quality of its primary financial institutions. The Company’s investment portfolio is maintained in accordance with its investment policy, which is designed to preserve capital, safeguard funds and limit exposure to risk. While the Company maintains cash deposits in FDIC insured financial institutions in excess of federally insured limits, it does not believe that it is exposed to significant credit risk due to the financial position of the depository institutions in which those deposits are held. The Company has not experienced any losses on such accounts. During the year ended December 31, 2022, revenues from the Company’s top two customers represented 65.9 % and 25.6 % of total revenues, respectively. During the year ended December 31, 2021, revenues from the Company’s top two customers represented 56.8 % and 35.8 % of total revenues, respectively. As of December 31, 2022, billed accounts receivable for two customers represented 78.4 % and 11.8 % of total billed receivables, respectively. As of December 31, 2021, billed accounts receivable for two customers represented 74.6 % and 21.3 % of total billed receivables, respectively. Cash, Cash Equivalents and Restricted Cash Cash and cash equivalents consist of readily available cash in checking accounts, money market funds and other MDS with original maturities of three months or less. The following table provides a reconciliation of cash, cash equivalents and restricted cash, reported within the consolidated statements of cash flows for the years ended December 31, (in thousands): 2022 2021 Cash and cash equivalents $ 55,610 $ 170,064 Restricted cash 831 842 Total cash, cash equivalents, and restricted cash presented in the $ 56,441 $ 170,906 As of December 31, 2022 and 2021 , the Company’s restricted cash consists of cash related to the Company’s clinical trials. Accounts Receivable, Net Accounts receivable, net, are recorded net of any allowance for current expected credit losses measured based on historical experience, current conditions, and reasonable and supportable forecasts. As of December 31, 2022 and 2021 , the Company has determined an allowance for expected credit losses is not material. Contract Balances The timing of revenue recognition, billings and cash collections results in billed accounts receivable, unbilled receivables (contract assets) and deferred revenue (contract liabilities) on the consolidated balance sheet, recorded on a contract-by-contract basis at the end of each reporting period. The majority of the Company’s contract amounts are invoiced as work progresses in accordance with agreed-upon contractual terms, either at periodic intervals or upon achievement of contractual milestones. Billing sometimes occurs subsequent to revenue recognition, resulting in contract assets. These contract assets are referred to as unbilled receivables and are reported within prepaid expenses and other current assets on the consolidated balance sheets. Unbilled receivables are transferred to accounts receivables, net, when the Company’s right of receipt becomes unconditional. Contract liabilities from the Company’s R&D agreements (R&D Agreements) arise when amounts invoiced to customers exceed revenues recognized based upon measure of progress achieved. Contract liabilities additionally include advanced payments from customers on certain contracts. Contract liabilities decrease as the Company recognizes revenue from the satisfaction of the related performance obligation. Contract liabilities are included in deferred revenue, current portion and deferred revenue, net of current portion, on the consolidated balance sheets. Marketable Debt Securities, Available-for-Sale The Company’s MDS portfolio, which is classified as available-for-sale, is comprised of money market funds, commercial paper, U.S. government securities, debt securities of U.S. financial institutions, corporate debt and asset backed securities. The objective of the Company’s investment policy is to preserve capital and maintain liquidity, with acceptable levels of risk. The investment policy limits interest-bearing security investments to certain types of debt and money market instruments issued by institutions with investment grade credit ratings, and it places restrictions on maturities and concentrations by asset class and issuer. MDS are classified as either current or non-current assets in the consolidated balance sheets based on each instrument's underlying contractual maturity date. Generally, at the time of purchase, MDS with remaining maturities of greater than three months and less than 12 months are classified as current assets and MDS with remaining maturities greater than 12 months for which the Company has the intent and ability to hold the investment for greater than 12 months are classified as non-current assets. The Company may sell certain of its MDS prior to their stated maturities for strategic purposes or in anticipation of credit deterioration. The Company’s MDS are stated at fair value, with unrealized gains and losses, net of tax, if any, reported in accumulated other comprehensive loss in the consolidated balance sheets, until disposition or maturity. Dividend and interest income, amortization/accretion of premiums and discounts, and realized gains and losses, which are determined using the specific identification method, are recognized in investment income, net, in the consolidated statements of operations and comprehensive loss. MDS are subject to a periodic impairment review. If the Company does not intend to sell and it is not more likely than not that it will be required to sell the security prior to recovery of its amortized cost basis, the Company will determine whether a decline in fair value below the amortized cost basis is due to credit-related factors. The credit loss is measured as the amount by which the debt security's amortized cost basis exceeds the estimate of the present value of cash flows expected to be collected, up to the difference between the amortized cost basis and the fair value. Impairment is assessed at the individual security level. Credit-related impairment is recognized as an allowance in the consolidated balance sheets with a corresponding adjustment to investment income, net, in the consolidated statements of operations and comprehensive loss. Any impairment that is not credit-related is recognized in accumulated other comprehensive loss in the consolidated balance sheets. The Company does not separately measure an allowance for credit losses on accrued interest receivables on its MDS. The Company writes off accrued interest receivables by reversing interest income in the period deemed uncollectible in investment income, net, in the Company’s consolidated statements of operations and comprehensive loss. Any accrued interest receivable on MDS is recorded in prepaid expenses and other current assets in the consolidated balance sheets. Property and Equipment, Net Property and equipment is recorded at cost and depreciated over the estimated useful lives of the assets using the straight-line method. Leasehold improvements are stated at cost and are amortized on a straight-line basis over the lesser of the remaining term of the related lease or the estimated useful lives of the assets. Repairs and maintenance costs are charged to expense as incurred and improvements and betterments are capitalized. Depreciation is calculated over their estimated useful lives as follows: Laboratory equipment 5 years Computer, software and office equipment 3 - 8 years Furniture and fixtures 5 years The useful lives of the Company’s assets are reviewed annually. When assets are retired or otherwise disposed of, the cost and accumulated depreciation are removed from the consolidated balance sheets and any resulting gain or loss is reflected in the consolidated statements of operations and comprehensive loss in the period realized. Intangible Assets , Net The Company records its intangible assets based on their fair values at the date of acquisition. The Company’s finite lived intangible assets related to acquired technologies has estimated remaining useful lives between three to 12 years as of December 31, 2022, and four to 13 years as of December 31, 2021. Amortization expense for the Company’s finite lived intangible assets is charged to research and development expense in the consolidated statements of operations and comprehensive loss on a straight-line basis over the assets’ estimated useful lives. Impairment losses on finite-lived intangible assets are recorded when indicators of impairment are present and the undiscounted cash flows estimated to be generated by those assets are less than the assets’ carrying amount. If such assets are considered impaired, the impairment to be recognized is measured by the amount by which the carrying amount of the assets exceeds the estimated fair value of the assets. During the fourth quarter of 2021, the Company determined the estimated undiscounted future cash flows of one of its acquired technology intangible assets was less than its carrying value and therefore recorded an impairment charge of $ 0.5 million. In the first quarter of 2022, the Company received a Notice of Termination of Collaboration and License agreement (Relaxin) between Bristol-Myers Squibb Company (BMS) and the Company (the Relaxin Agreement) from BMS to be effective three months from receipt of the notification. Due to this termination notice and the Company’s determination that the asset had no alternative future use, the Company concluded the net carrying value of the BMS Relaxin intangible asset was greater than its estimated fair value and therefore recorded an impairment charge of $ 2.5 million. In the second quarter of 2022, the Company received verbal notification from BMS of its intent to terminate the Collaboration and License Agreement (FGF-21) between BMS and the Company (the FGF-21 Agreement), which was followed by a formal notification on July 18, 2022 to be effective three months from receipt of the formal notification date. Due to this termination notice and the Company’s determination that the asset had no alternative future use, the Company concluded the net carrying value of the BMS FGF-21 intangible asset was greater than its estimated fair value and therefore recorded an impairment charge of $ 7.2 million. The Company’s intangible assets also include acquired in-process research and development (IPR&D) from a business combination, which is recognized as an indefinite lived intangible asset until completion or abandonment of the related R&D activities. When the related R&D activity is completed, the IPR&D intangible asset is reclassified as a finite-lived intangible asset and amortized over the remaining useful life. The Company’s acquired IPR&D is tested for impairment annually or more frequently if events or changes in circumstances between annual tests indicate that the asset may be impaired. On October 18, 2022, the Company announced a reprioritization of its product pipeline after conducting a strategic assessment that considered its cash runway and its product pipeline near term value creation opportunities, among other factors. As a result of this assessment, the Company paused its internal development of ARX788 and, among other potential activities, indicated it will seek development partners to further the development of ARX788 outside of China. The Company determined this reprioritization was a qualitative trigger of potential impairment of its IPR&D asset and had a quantitative analysis completed as of the reprioritization date. The quantitative analysis determined the IPR&D asset was not impaired as of the reprioritization date. The Company’s annual impairment test for the years ended December 31, 2022 and 2021, performed in the fourth quarter, did not result in additional impairment losses related to its intangible assets. While the Company’s current and historical operating losses and negative cash flows are possible indicators of impairment, management believes future cash flows to be generated by its remaining long-lived assets support the carrying value. Fair Value of Financial Instruments The Company’s financial instruments consist primarily of cash and cash equivalents, MDS, accounts receivable, accounts payable and accrued liabilities. The carrying amounts of cash and cash equivalents, accounts receivable, accounts payable and accrued liabilities are considered to be representative of their respective fair values because of the relatively short-term nature of those instruments. The accounting guidance defines fair value, establishes a consistent framework for measuring fair value and expands disclosure for each major asset and liability category measured at fair value on either a recurring or nonrecurring basis. Fair value is defined as an exit price, representing the amount that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants. As such, fair value is a market-based measurement that should be determined based on assumptions that market participants would use in pricing an asset or liability. As a basis for considering such assumptions, the accounting guidance establishes a three-tier fair value hierarchy, which prioritizes the inputs used in measuring fair value as follows: Level 1: Inputs based on quoted market prices for identical assets or liabilities in active markets at the measurement date. Level 2: Observable inputs other than quoted prices included in Level 1, such as quoted prices for similar assets and liabilities in active markets; quoted prices for identical or similar assets and liabilities in markets that are not active; or other inputs that are observable or can be corroborated by observable market data. Level 3: Inputs which reflect management’s best estimate of what market participants would use in pricing the asset or liability at the measurement date. The inputs are unobservable in the market and significant to the instrument’s valuation. Assets and liabilities are classified based on the lowest level of input that is significant to the fair value measurements. The Company reviews the fair value hierarchy classification on a quarterly basis. Clinical Trial Accruals As part of the process of preparing the consolidated financial statements, the Company is required to estimate expenses resulting from obligations under contracts with vendors, clinical research organizations, consultants and under clinical site agreements relating to conducting clinical trials. The financial terms of these contracts vary and may result in payment flows that do not match the periods over which materials or services are provided under such contracts. The Company’s objective is to reflect the appropriate clinical trial expenses in its consolidated financial statements by recording those expenses in the period in which services are performed and efforts are expended. The Company accounts for these expenses according to the progress of the clinical trial as measured by patient progression and the timing of various aspects of the clinical trial. Management determines accrual estimates, as of each balance sheet date, through discussions with applicable personnel and outside service providers as to the progress of clinical trials. During a clinical trial, the Company adjusts its expense recognition if actual results differ from previous estimates. Leases The Company determines if an arrangement is a lease at the inception of the contract. The asset component of the Company’s operating leases is recorded as a ROU asset and the liability component is recorded as current portion of operating lease liabilities and operating lease liabilities, net of current portion, in the consolidated balance sheets. At the commencement, reassessment or modification date, the cost of the ROU asset includes all the following, if any: the amount of the initial measurement of the lease liability, any lease payments made to the lessor at or before the commencement date minus any lease incentive received and any initial direct costs incurred by the lessee. Operating lease liabilities are recognized based on the present value of lease payments over the lease term at the commencement date. The Company uses an incremental borrowing rate based on the information available at commencement date in determining the present value of lease payments if an implicit rate of return is not provided within the lease contract. When evaluating its incremental borrowing rate, management considers its borrowing rate on external collateralized debt with a term commensurate with the lease term, if any, or in the absence of external debt, the average incremental borrowing rate of its peer group. These amounts are estimated at the inception of or upon reassessment of a lease arrangement. Lease cost is recognized on a straight-line basis over the lease term, and includes amounts related to short-term leases. Variable lease costs, such as common area maintenance, real estate taxes and management fees which do not depend on an index or rate are recognized as incurred. Short-term leases of 12 months or less are expensed as incurred, which approximates the straight-line basis due to the short-term nature of the leases. The Company has elected not to separate lease and non-lease components. ROU assets and operating lease liabilities are remeasured upon lease reassessment using the present value of remaining lease payments and estimated incremental borrowing rates. The Company reviews any changes to its lease agreements for potential modifications and/or indicators of impairment of the respective ROU asset. Revenue Recognition The Company determines revenue recognition for arrangements within the scope of ASC Topic 606, Revenue from Contracts with Customers (ASC 606) by performing the following five steps: (i) identify the contract; (ii) identify the performance obligations in the contract; (iii) determine the transaction price; (iv) allocate the transaction price to the performance obligations in the contract; and (v) recognize revenue when, or as, the Company satisfies a performance obligation. A performance obligation is a promise in a contract to transfer a distinct good or service and is the unit of accounting in ASC 606. A contract’s transaction price is allocated among each distinct performance obligation based on relative standalone selling price and recognized as revenue when, or as, the applicable performance obligation is satisfied. The terms of the Company’s R&D Agreements include upfront fees, R&D funding or reimbursements, milestone and other contingent payments for the achievement of defined objectives and certain preclinical, clinical, regulatory and sales-based events, as well as royalties on sales of commercialized products. Agreements with certain upfront payments may require deferral of revenue recognition to a future period until the Company performs the obligations under these agreements. The Company uses the most likely amount method to estimate variable consideration for event-based milestones and other contingent payments and have been fully constrained given the degree of uncertainty around the occurrence of such events. The Company continues to re-evaluate the transaction price in each reporting period as contingencies are resolved and other changes in circumstances occur. The Company is required to adjust the transaction price for the effects of the time value of money if the timing of payments agreed to by the parties to the contract, explicitly or implicitly, provides the Company or its customer with a significant benefit of financing the transfer of goods or services. The Company concluded that its contracts with the customers do not contain a significant financing component because the payment structure of the R&D Agreements arises from reasons other than providing a significant benefit of financing. Taxes assessed by a governmental authority that are both imposed on and concurrent with a specific revenue-producing transaction, that are collected by the Company from a customer, are excluded from revenues. R&D Agreements The Company analyzes its R&D Agreements to assess whether they are within the scope of ASC Topic 808, Collaborative Arrangements (ASC 808), which includes determining whether such arrangements involve joint operating activities performed by parties that are both active participants in the activities and exposed to significant risks and rewards dependent on the commercial success of such activities. This assessment is performed at contract inception and again, if changes in either the roles of the participants in the arrangement or the participants’ exposure to significant risks and rewards dependent on the ultimate commercial success of the arrangement are identified. For each of the periods presented, the Company determined that its contracts with customers do not fall within the guidance in ASC 808 as the Company is not exposed to significant risks that are dependent on commercial success of the collaborative activity. License Fees As part of the R&D Agreements, the Company licenses its intellectual property to customers for fees, which many times includes the receipt of upfront fees. If a license to the Company’s intellectual property is determined to be distinct from the other promises or performance obligations identified in the agreement, the Company recognizes revenue from non-refundable, upfront fees allocated to the license when the license is transferred to the customer. In assessing whether a promise or performance obligation is distinct from the other promises, the Company considers factors such as the research, development, manufacturing and commercialization capabilities of the licensee and the availability of the associated expertise in the general marketplace. In addition, the Company considers whether the licensee can benefit from a promise for its intended purpose without the receipt of the remaining promise, whether the value of the promise is dependent on the unsatisfied promise, whether there are other vendors that could provide the remaining promise, and whether it is separately identifiable from the remaining promise. For licenses that are combined with other promises, the Company utilizes judgment to assess the nature of the combined performance obligation to determine whether the combined performance obligation is satisfied over time or at a point in time and, if over time, the appropriate method of measuring progress for purposes of recognizing revenue. For those license related performance obligations that are satisfied over time, the Company measures progress through actual effort, including hours incurred, and an estimation of time to completion based on the budget and research workplan. Typical agreements require the transfer of knowledge so the customer can effectively use the license and the Company believes these measurements accurately represent the transfer of knowledge through its clinical research services. The Company evaluates the measure of progress each reporting period and, if circumstances change over time, the Company will update its measure of progress to reflect any changes in the outcome of the performance obligation and, therefore, adjust the measure of performance and related revenue recognition. The measure of progress, and thereby periods over which revenue should be recognized, is subject to estimates by management and may change over the course of the agreement. Such a change could have a material impact on the amount of revenues the Company records in future periods. During the second half of 2021, the Company re-evaluated the measure of progress for a compound under one of its R&D Agreements, which resulted in an increased estimate in the timing and efforts of satisfaction of the Company’s performance obligations under the agreement. This change did not have an impact on the transaction price and/or the variable consideration to be received under the agreement. As a result of the re-evaluation, the Company recognized a cumulative catch-up adjustment reducing revenue by approximately $ 1.4 million with an equal increase in total contract liabilities (i.e., deferred revenue) from upfront payments as of December 31, 2021. The Company’s periodic reassessments, during the year ended December 31, 2022 , did not result in any adjustments to its current revenue recognition methodology. Reimbursements As part of the R&D Agreements where the Company only provides R&D services, the Company is reimbursed by the customer for certain costs incurred as agreed to in the research plan. The Company elected the practical expedient for certain R&D reimbursements which allows it to recognize revenue in the amount for which the Company has a right to invoice if its right to consideration is an amount corresponding directly to the value of completed performance to date. The Company estimates variable consideration, if any, at contract inception and each reporting period, to determine if there were any changes in the transaction price. The transaction price will be adjusted to the extent the risk of significant revenue reversal in the amount of cumulative revenue recognized will not occur when the uncertainty associated with the milestones are subsequently resolved. Any such adjustments are recorded on a cumulative catch-up basis and revenues and earnings are impacted in the period of adjustment. Milestones and Other Contingent Payments At the inception of each R&D Agreement that includes milestones and other contingent payments, the Company evaluates whether the milestones or other contingent payments are considered probable of being achieved and estimates the amount to be included in the initial transaction price using the most likely amount method. If it is probable that a significant revenue reversal would not occur, the associated value is included in the transaction price. Milestones or other contingent payments are only included in the transaction price to the extent the risk of a significant revenue reversal in the amount of cumulative revenue recognized will not occur when the uncertainty associated with the milestones are subsequently resolved. The Company evaluates factors such as the scientific, clinical, regulatory, commercial, and other risks that must be overcome to achieve the particular contingency in making this assessment. There is considerable judgment involved in determining whether it is probable that a significant revenue reversal would not occur. At the end of each subsequent reporting period, the Company reevaluates the probability of achievement of all milestones and other contingencies subject to constraint and, if necessary, adjusts its estimate of the overall transaction price. Any such adjustments are recorded on a cumulative catch-up basis and revenues and earnings are impacted in the period of adjustment. Sales-Based Milestones and Royalties on Sales of Commercialized Products For R&D Agreements that include sales-based milestone payments and royalties which are the result of a customer-vendor relationship and for which the license is deemed to be the predominant item to which the royalties relate, the Company recognizes revenue at the later of (i) when the related sales occur, or (ii) when the performance obligation to which some or all of the royalty has been allocated has been satisfied or partially satisfied. R&D Services Promises under the Company’s R&D Agreements may include R&D services to be performed by the Company on behalf of the counterparty. If these services are determined to be distinct from the other promises or performance obligations identified in the arrangement, the Company recognizes the transaction price allocated to these services as revenue over time based on an appropriate measure of progress of the performance. If these services are determined not to be distinct from the other promises or performance obligations identified in the arrangement, the Company recognizes the transaction price allocated to the combined performance obligation as the related per

Balance Sheets Details

Balance Sheets Details	12 Months Ended
	Dec. 31, 2022
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Balance Sheets Details	3. Balance Sheet Details Prepaid Expenses and Other Current Assets Prepaid expenses and other current assets consist of the following as of December 31, (in thousands): 2022 2021 Tax receivable $ 1,506 $ 104 Prepaid R&D costs 1,476 2,467 Prepaid insurance and service contracts 1,424 1,860 Interest receivable - marketable debt securities 168 — Other 319 230 Total $ 4,893 $ 4,661 Property and Equipment, Net Property and equipment, net, consist of the following as of December 31, (in thousands): 2022 2021 Laboratory equipment $ 7,559 $ 6,851 Computers, software and office equipment 512 489 Leasehold improvements 467 384 Office furniture and fixtures 123 126 8,661 7,850 Accumulated depreciation and amortization ( 5,617 ) ( 4,866 ) Total $ 3,044 $ 2,984 Depreciation and amortization expense for property and equipment for the years ended December 31, 2022 and 2021 was $ 0.8 million and $ 0.6 million, respectively. Accrued Liabilities Accrued liabilities consist of the following as of December 31, (in thousands): 2022 2021 Accrued R&D costs (1) $ 4,069 $ 9,043 Accrued compensation 3,494 3,664 Accrued audit, tax and filing fees 1,703 556 Accrued directors and officers insurance premium (2) 926 — Accrued other 1,122 862 Total $ 11,314 $ 14,125 __________ (1) Includes $ 99 and $ 250 of accrued R&D costs due to related parties as of December 31, 2022 and 2021, respectively. (2) Represents the remaining balance due under the Company’s insurance premium financing agreement, which is payable in equal monthly installments through May 2023 and bears interest at approximately 3.4 % per annum.

Intangible Assets, Net

Intangible Assets, Net	12 Months Ended
	Dec. 31, 2022
Goodwill and Intangible Assets Disclosure [Abstract]
Intangible Assets, Net	4. Intangible Assets, Net Intangible assets, net, consist of the following as of and for the year ended December 31, 2022 (in thousands, except years): Weighted- Gross Impairment (1) Accumulated Intangible Acquired technologies 8.8 $ 24,330 $ ( 9,660 ) $ ( 10,360 ) $ 4,310 IPR&D 20,940 — — 20,940 Total $ 45,270 $ ( 9,660 ) $ ( 10,360 ) $ 25,250 __________ (1) Includes the impairment of BMS Relaxin and BMS FGF-21 intangible assets, as more fully described within the Intangible Assets, Net subsection of Note 2—Summary of Significant Accounting Policies . These intangible asset impairments are presented in the consolidated statements of operations and comprehensive loss as impairment of intangible assets within operating activities. Intangible assets, net, consist of the following as of and for the year ended December 31, 2021 (in thousands, except years): Weighted- Gross Additions Impairment (1) Accumulated Intangible Acquired technologies 9.7 $ 23,870 $ 1,250 $ ( 513 ) $ ( 9,585 ) $ 15,022 IPR&D 20,940 — — — 20,940 Total $ 44,810 $ 1,250 $ ( 513 ) $ ( 9,585 ) $ 35,962 __________ (1) Represents the impairment of an acquired technology intangible asset, as more fully described within the Intangible Assets, Net subsection of Note 2—Summary of Significant Accounting Policies . These intangible asset impairments are presented in the consolidated statements of operations and comprehensive loss as impairment of intangible assets within operating activities. Amortization expense for intangible assets for the years ended December 31, 2022 and 2021 was $ 1.1 million and $ 1.6 million, respectively. Future amortization expense is as follows as of December 31, 2022 (in thousands): Year ending December 31, 2023 $ 629 2024 630 2025 629 2026 364 2027 356 Thereafter 1,702 Total $ 4,310

Marketable Debt Securities, Ava

Marketable Debt Securities, Available-for-Sale	12 Months Ended
	Dec. 31, 2022
Investments, Debt and Equity Securities [Abstract]
Marketable Debt Securities, Available-for-Sale	5. Marketable Debt Securities, Available-for-Sale The following table summarizes the Company’s MDS as of December 31, 2022 (in thousands): Weighted-Average Amortized Unrealized Unrealized Fair Classified as current assets: Commercial paper 1 or less $ 15,803 $ 1 $ ( 23 ) $ 15,781 Certificates of deposit 1 or less 7,500 2 ( 25 ) 7,477 U.S. government securities 1 or less 5,001 — ( 30 ) 4,971 Corporate bonds 1 or less 646 — ( 2 ) 644 Total Marketable debt securities, 1 or less $ 28,950 $ 3 $ ( 80 ) $ 28,873 Classified as non-current assets: U.S. government securities 1.4 $ 6,979 $ — $ ( 184 ) $ 6,795 Corporate bonds 1.5 6,824 — ( 192 ) 6,632 Asset backed securities 1.8 2,999 — ( 45 ) 2,954 Non-U.S. government securities 1.5 423 — ( 11 ) 412 Total Marketable debt securities, 1.5 $ 17,225 $ — $ ( 432 ) $ 16,793 Total 0.7 $ 46,175 $ 3 $ ( 512 ) $ 45,666 As of December 31, 2022, interest receivables related to MDS of $ 0.2 million are included in prepaid expenses and other current assets in the consolidated balance sheets. Accumulated unrealized losses on MDS that have been in a continuous loss position for less than 12 months and for more than 12 months as of December 31, 2022, were as follows (in thousands): Less than 12 months More than 12 months Estimated Gross Estimated Gross Commercial paper $ 12,803 $ ( 22 ) $ — $ — U.S. government securities 11,765 ( 216 ) — — Corporate bonds 7,276 ( 193 ) — — Certificates of deposit 2,975 ( 25 ) — — Asset backed securities 2,954 ( 45 ) — — Non-U.S. government securities 412 ( 11 ) — — Total $ 38,185 $ ( 512 ) $ — $ — As of December 31, 2022, a total of 22 of the securities were in an unrealized loss position. The Company evaluated its MDS and concluded that the losses were caused by interest rate fluctuations, as opposed to credit quality. Because the Company does not intend to sell its MDS and it is not more likely than not that the Company will be required to sell its MDS before recovery of their amortized cost bases, which may be maturity, the Company does not consider its MDS to be impaired. Realized gains and losses on MDS were not significant for the year ended December 31, 2022 .

Fair Value Measurements

Fair Value Measurements	12 Months Ended
	Dec. 31, 2022
Fair Value Disclosures [Abstract]
Fair Value Measurements	6. Fair Value Measurements The following table presents the Company’s financial assets measured at fair value on a recurring basis as of December 31, 2022 (in thousands): Total Level 1 Level 2 Level 3 Cash equivalents: Certificates of deposit $ 24,000 $ — $ 24,000 $ — Commercial paper 15,352 — 15,352 — Money market funds 12,743 12,743 — — Total cash equivalents $ 52,095 $ 12,743 $ 39,352 $ — Marketable debt securities, available-for-sale: Commercial paper $ 15,781 $ — $ 15,781 $ — Certificates of deposit 7,477 — 7,477 — U.S. government securities 4,971 — 4,971 — Corporate bonds 644 — 644 — Total Marketable debt securities, available-for-sale $ 28,873 $ — $ 28,873 $ — Marketable debt securities, available-for-sale, net of U.S. government securities $ 6,795 $ — $ 6,795 $ — Corporate bonds 6,632 — 6,632 — Asset backed securities 2,954 — 2,954 — Non-U.S. government securities 412 — 412 — Total Marketable debt securities, available-for-sale, $ 16,793 $ — $ 16,793 $ — As of December 31, 2021, the Company had $ 162.6 million, in cash equivalents which consisted of money market funds which were valued based on quoted market prices for identical assets in active markets at their measurement date. During the years ended December 31, 2022 and 2021 , there were no transfers into or out of Level 3 of the fair value hierarchy. As of December 31, 2022 and 2021 , the Company had no liabilities measured at fair value on a recurring basis.

Commitments and Contingencies

Commitments and Contingencies	12 Months Ended
	Dec. 31, 2022
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	7. Commitments and Contingencies Intellectual Property Licenses Lonza On December 11, 2019, the Company entered into a commercial license agreement with Lonza Sales AG (Lonza) for a fully paid-up license to use Lonza’s GS System with the Company’s non-natural amino acid technology (the 2019 Agreement). This agreement replaces the prior agreements the Company entered into with Lonza for the GS system in 2009 and 2015. The 2019 Agreement, as amended, includes an option to evaluate and sublicense Lonza’s piggyBac Expression Technology Patent Rights with the Company’s technology. Under the 2019 Agreement, the Company paid a license fee of approximately 2.0 million Swiss Francs (or approximately $ 2.1 million) for the fully paid up license to the GS System and had an option to a license to Lonza’s piggyBac technology with the Company’s non-natural amino acid technology. The Company notified Lonza effective July 1, 2022, that it will not exercise the option and will no longer pursue further development efforts related to the piggyBac technology. The Scripps Research Institute In August 2003, the Company entered into a license agreement with The Scripps Research Institute (TSRI) for the development and commercialization and right to sublicense products using TSRI materials and technology (the TSRI Agreement). Under the TSRI Agreement, the Company is obligated to pay royalties in the low single-digits based on the amount of annual sales for licensed products and sublicensing royalties of licensed products in the low single-digits on annual sublicensing revenues, if any. During the years ended December 31, 2022 and 2021, the Company’s payments to TSRI were $ 0.1 million and $ 1.7 million, respectively. Litigation From time to time, the Company may be involved in various lawsuits, legal proceedings, or claims that arise in the ordinary course of business. Management believes there are no claims or actions pending against the Company as of December 31, 2022 which will have, individually or in the aggregate, a material adverse effect on its business, liquidity, financial position, or results of operations. Litigation, however, is subject to inherent uncertainties, and an adverse result in these or other matters may arise from time to time that may harm the Company’s business. Indemnification In accordance with the Company’s amended and restated memorandum and articles of association, the Company has indemnification obligations to its officers and directors for certain events or occurrences, subject to certain limits, while they are serving in such capacity. There have been no claims to date, and the Company has a directors and officers liability insurance policy that may enable it to recover a portion of any amounts paid for future claims.

Leases

Leases	12 Months Ended
	Dec. 31, 2022
Lessee Disclosure [Abstract]
Leases	8. Leases The Company has operating leases for its corporate offices and certain equipment. The leases have remaining lease terms of approximately two to five years . The Company is responsible for payment of taxes and operating expenses for the building, in addition to monthly base rent in the initial amount of approximately $ 0.1 million, with 3 % annual increases. Upon execution of the lease in March 2005, the Company provided a security deposit of approximately $ 0.3 million which is included in other long-term assets in the consolidated balance sheets. The Company has determined that the lease is an operating lease for accounting purposes. In March 2005, the Company executed a lease for approximately 36,000 square feet. Effective December 1, 2021, the Company exercised its option to extend its existing facility lease for an additional five years (the Lease Amendment) through November 30, 2027. Upon delivery of the Company’s notice to exercise the right to extend the term option in the lease, the Company reassessed its facility lease. In December 2021, upon determination of the lease payments, the Company again reassessed its facility lease. The reassessments of the Lease Amendment was determined to qualify as a change of accounting for the existing lease rather than a separate contract. As such, the ROU assets and operating lease liabilities were remeasured using an incremental borrowing rate as of the reassessment date. The Company determined there was no difference between the remeasured ROU asset and the operating lease liabilities and therefore no gain or loss was recognized and no impairment of the ROU asset occurred. During the fourth quarter of 2021, the Company recorded an increase in the ROU assets and lease liabilities of $ 11.5 million. The Company no longer has a right to extend the lease term. The components of lease expense are as follows for the years ended December 31, (in thousands): 2022 2021 Operating lease expenses R&D: Operating lease costs $ 2,217 $ 1,203 Variable lease costs (1) 1,090 1,190 Operating lease expenses G&A: Operating lease costs 509 232 Variable lease costs (1) 236 231 Total operating leases expense $ 4,052 $ 2,856 ____________ (1) Includes short-term lease costs which are immaterial. Supplemental balance sheet information related to operating leases is as follows as of December 31, (in thousands): 2022 2021 ROU assets, net $ 10,968 $ 12,737 Operating lease liabilities, current $ 1,734 $ 915 Operating lease liabilities, net of current $ 10,245 $ 12,212 Supplemental cash flow information related to leases is as follows for the years ended December 31, (in thousands): 2022 2021 Cash paid for amounts included in the measurement of Operating cash flows used for operating leases $ 1,874 $ 1,742 Weighted-average remaining lease term in years 4.9 5.9 Weighted-average discount rate 7.63 % 7.63 % Future lease liabilities are as follows a s of December 31, 2022 (in thousands): Year ending December 31, 2023 $ 2,814 2024 2,896 2025 2,982 2026 3,071 2027 2,892 Thereafter — 14,655 Less interest expense ( 2,676 ) Total $ 11,979

Ordinary Shares and Convertible

Ordinary Shares and Convertible Preferred Shares	12 Months Ended
	Dec. 31, 2022
Convertible Preferred Ordinary Shares And Ordinary Shares [Abstract]
Ordinary Shares and Convertible Preferred Shares	9. Ordinary Shares and Convertible Preferred Shares Ordinary Shares As described in Note 1—Description of Business and Basis of Presentation , the Company completed an IPO in June 2021 of 7,000,000 ADSs (i.e., 49,000,000 ordinary shares) and the issuance of 892,831 ADSs (i.e., 6,249,817 ordinary shares). Each ADS represents seven ordinary shares of the Company. At-the-Market Offering Agreement On July 29, 2022, the Company entered into an at-the-market sales agreement with Cowen and Company LLC, pursuant to which the Company was able to offer and sell its ADSs, each representing seven of the Company’s ordinary shares, having an aggregate offering price of up to $ 80.0 million (the ATM Program). During the first quarter of 2023, the Company issued and sold 16,575,826 of its ADSs at an average selling price of $ 4.83 per ADS, for gross proceeds of approximately $ 80.0 million, less sales commissions of approximately $ 2.0 million, for net proceeds of approximately $ 78.0 million. Accordingly, as of March 10, 2023, the ATM Program is complete. Convertible Preferred Shares During the year ended December 31, 2021, the Company’s Series A and Series B convertible preferred shares were classified as temporary equity instead of shareholders’ equity in accordance with U.S. GAAP for the classification and measurement of potentially redeemable securities, as the shares were conditionally redeemable upon certain change in control events that are outside the Company’s control, including the liquidation, sale, or transfer of control of the Company. Upon such change in control events, holders of the convertible preferred shares could cause its redemption. Upon completion of the Company’s IPO, the Series A and Series B convertible preferred shares were automatically converted into ordinary shares and are no longer outstanding. Amended and Restated Memorandum of Association Concurrent with the closing of the IPO, the Company amended and restated its memorandum of association which authorizes the issuance of 500,000,000 ordinary shares and 100,000,000 of such class or classes (however designated) of shares as the Company’s board of directors may determine (the Undesignated Shares). As of December 31, 2022, the Company has no issued or outstanding Undesignated Shares. In February 2023, the Company’s board of directors designated the previously Undesignated Shares as ordinary shares. Accordingly, following this designation the Company had 600,000,000 authorized ordinary shares.

Revenues

Revenues	12 Months Ended
	Dec. 31, 2022
Revenue from Contract with Customer [Abstract]
Revenues	10. Revenues During the years ended December 31, 2022 and 2021, the Company recognized revenue over time under each of its R&D Agreements as its performance obligations were satisfied. Variable consideration, such as development and regulatory milestones previously constrained is recognized to the extent a significant revenue reversal in the amount of cumulative revenue recognized will not occur when the uncertainty associated with the variable consideration is subsequently resolved. Revenue recognized was earned under the Company’s R&D Agreements and is summarized below based on the nature of payment type for the years ended December 31, (in thousands): Timing of Transfer of Goods or Services 2022 2021 Over time: License fees (1) $ 3,442 $ 3,533 R&D services 2,140 2,072 Reimbursements 820 1,850 Point in time: Milestones 1,000 — Total revenues $ 7,402 $ 7,455 _____________ (1) 2021 license fees include a cumulative catch-up adjustment reducing revenue by approximately $ 1.4 million with an equal increase in total contract liabilities as of December 31, 2021, for changes in total estimated effort to be incurred in the future to satisfy the performance obligation. Remaining Performance Obligations and Deferred Revenue As of December 31, 2022 and 2021, unsatisfied remaining performance obligations for minimum full-time equivalent (FTE) services under the Company’s R&D Agreements totaled $ 0.1 million and $ 1.2 million, respectively. As of December 31, 2022, the Company’s expects to recognize the remaining deferred revenue related to R&D services under its existing R&D Agreements during the year ended December 31, 2023. In addition, as of December 31, 2022 and 2021, the Company had deferred revenue of $ 1.7 million and $ 5.7 million, respectively, which was primarily related to (i) the combined performance obligation for transfer of the Company’s license and R&D services and (ii) conducting R&D activities, which are a separate performance obligation in the Company’s contracts pursuant to research plans under the R&D agreements. The Company anticipates that the remaining performance obligations as of December 31, 2022 will be satisfied over the next one to four years . Zhejiang Medicine Co. Ltd. (ZMC) In June 2013, the Company entered into a co-development and license agreement with ZMC to develop and commercialize ARX788 (the ZMC Agreement). In March 2019, the ZMC Agreement was transferred to NovoCodex Biopharmaceutical Ltd (NovoCodex), a subsidiary of ZMC. Under the ZMC Agreement, both companies will continue the development of ARX788. ZMC is responsible, at its sole expense, for making commercially reasonable efforts to develop, obtain regulatory approval for and commercialize the licensed products in China and fund the development of the product in Australia or other jurisdictions approved by a joint steering committee through Phase 1 clinical trials. ZMC will receive commercial rights in China while Ambrx retains commercial rights outside of China and will receive low double-digit tiered royalties on sales of the product in China. Under the terms of the ZMC Agreement, as amended, ZMC received an exclusive right and license for the prevention, and treatment of human diseases and conditions associated with αHer2 with the right to grant sublicenses under the Company’s existing patents and know how. Under the agreement, the Company is entitled to receive tiered royalties as high as mid-teens range on aggregate net sales of ARX788 in the People’s Republic of China (PRC). The Company will be entitled to receive these royalties until the later of the expiration of the applicable patent rights or 20 years after the first commercial sale of the product in the PRC. In addition, the Company is obligated to pay royalties in a mid-single digit to low-teens percentage range of any sublicensing profit that the Company may receive outside of the PRC, depending on what phase of clinical development has been completed at the time of transfer, or a low single digit percentage range on any net sales that the Company or its successors may receive from sales of ARX788 outside of the PRC, if the market authorization of ARX788 is based on Phase 1 clinical data obtained during the Company’s collaboration with ZMC. BeiGene Ltd. (BeiGene) In March 2019, the Company entered into a collaboration and exclusive license agreement with BeiGene for the development and commercialization of next-generation biologics drugs (the BeiGene Agreement) and received an upfront license payment to fund the initial discovery and research activities of $ 10.0 million. Under the terms of the BeiGene Agreement, BeiGene will have worldwide rights to develop and commercialize any drug products resulting from the collaboration. BeiGene may terminate the BeiGene Agreement upon three months ’ written notice. The Company or BeiGene may terminate the BeiGene Agreement for cause for safety reasons or upon other party’s material breach that remains uncured after receipt of notice thereof, or upon certain bankruptcy or insolvency proceedings. The Company may also terminate the BeiGene Agreement for cause due to BeiGene’s failure to use commercially reasonable efforts in the development and commercialization of products. The Company is eligible to receive payments for R&D services performed by its employees based on the annual rate per FTE defined in the agreement, for a minimum of two and up to 25 FTEs. BeiGene will reimburse third-party costs incurred by the Company as agreed to per the BeiGene Agreement. The Company is also eligible to receive additional upfront payments if BeiGene elects to initiate additional programs and milestone payments upon achievement of certain potential development, regulatory, and sales-based milestones for all programs. The Company is also entitled to receive tiered royalties on a product-by-product basis on aggregate worldwide net sales of each product. Since inception and through December 31, 2022, the license to the Company’s intellectual property and R&D services performed by the Company are combined as a single performance obligation. Accordingly, the Company recognizes revenue for the transaction price based upon efforts or inputs to satisfy its performance obligation relative to the total expected inputs. Due to the uncertainty in the achievement of the development and regulatory milestones, the variable consideration associated with these future milestone payments has been fully constrained (excluded) from the transaction price until such time that the Company concludes that it is probable that a significant reversal of previously recognized revenue will not occur. These estimates are re-assessed at each reporting period. In November 2022, the Company received notification from BeiGene of its intent to terminate the HER-3 ADC research program, effective January 23, 2023 (the BeiGene Notification). Prior to receipt of the BeiGene Notification, deferred revenue would have been recognized through February 2023. However, the BeiGene Notification resulted in a re-evaluation of the measure of progress for the program and the Company accelerating revenue recognition associated with the remaining deferred revenue as of the notification date. In March 2023, the Company and BeiGene extended the initial research term for an additional two years . NovoCodex Biopharmaceuticals Ltd. (NovoCodex) In October 2019, the Company entered into a co-development and commercialization agreement with NovoCodex, a majority owned company of ZMC to develop and commercialize Ambrx’s internally developed site-specific ADCs (the NovoCodex Agreement), and received an upfront, non-refundable, and non-creditable payment of $ 2.0 million. The license to the Company’s intellectual property and R&D services performed by the Company until the initial manufacturing run or technology transfer are combined as a single performance obligation. R&D services performed after the initial manufacturing run or technology transfer are considered to represent a separate performance obligation. NovoCodex may terminate the NovoCodex Agreement upon six months written notice. The Company or NovoCodex may terminate the NovoCodex Agreement for cause for safety reasons or upon other party’s material breach that remains uncured after receipt of notice thereof, or upon certain bankruptcy or insolvency proceedings. The Company may also terminate the NovoCodex Agreement for cause due to NovoCodex’s failure to use commercially reasonable efforts in the development and commercialization of products. Under the terms of the NovoCodex Agreement, NovoCodex is responsible for developing and commercializing ARX305 in China while Ambrx is responsible for developing and commercializing ARX305 outside of China. NovoCodex will fund global development activities through the end of Phase 1 clinical trials. The Company is eligible to receive payments for R&D services for a minimum of one FTE based on the annual rate defined in the agreement. In addition, the Company is eligible to receive milestone payments upon achievement of certain clinical development milestone. During the fourth quarter of 2022 , the Company recognized milestone revenue of $ 1.0 million upon dosing of the first patient with ARX305 pursuant to the NovoCodex Agreement. The Company is also eligible to receive tiered royalties on a product-by-product basis on aggregate worldwide net sales of each product. NovoCodex is also eligible to share in a portion of ARX305 product sales outside of China. In the event the Company transfers or licenses the Phase 1 clinical data to a third party, NovoCodex is entitled to royalties on aggregate net sales of ARX305 outside of China. Since inception and through December 31, 2022, the Company has identified two performance obligations for all promises under the NovoCodex Agreement. Accordingly, the Company recognizes revenue for the transaction price based upon efforts or inputs to satisfy its performance obligations relative to the total expected inputs. Due to the uncertainty in the achievement of the development milestones, the variable consideration associated with these future milestone payments has been fully constrained (excluded) from the transaction price until such time that the Company concludes that it is probable that a significant reversal of previously recognized revenue will not occur. These estimates are re-assessed at each reporting period. Sino Biopharmaceutical Co., Ltd. (Sino Biopharma) In January 2020, the Company entered into a co-development and license agreement with Sino Biopharma pursuant to which the Company (i) assigned to Sino Biopharma existing and future patent rights in the People’s Republic of China (inclusive of Hong Kong, Macau and Taiwan, the Sino Territory) to ARX822 and ARX102 (each a preclinical compound) and (ii) granted exclusive rights and licenses in the Sino Territory to develop and manufacture ARX822 and ARX102 (the Sino Agreement). Sino Biopharma is solely responsible, at its own expense, for marketing, selling, offering for sale, distributing, promoting and otherwise commercializing the products in the Sino Territory. Sino Biopharma shall use commercially reasonable efforts to obtain regulatory approval for and commercialize each product. Sino Biopharma may terminate the Sino Agreement upon six months ’ written notice. Under the terms of Sino Agreement, the Company received an upfront payment of $ 10.0 million, which was initially subject to refund by the Company to Sino Biopharma for nonperformance; however, as of December 31, 2020, the upfront payment is no longer subject to refund. Sino Biopharma is solely responsible for costs associated with Investigational New Drug enabling activities and for providing the Company with study drug for up to 100 patients enrolled in a Phase 1 clinical trial for each of ARX822 and ARX102, if any. The Company is also eligible to receive milestone payments upon achievement of certain potential development and regulatory milestones for each program. In addition, the Company is also entitled to receive tiered royalties on a product-by-product basis on aggregate worldwide net sales of each product. With respect to each licensed product, the royalty term will terminate 12 years after the first commercial sale of such licensed product in the PRC. Since inception and through December 31, 2022, the Company has identified one performance obligation per each preclinical compound for all promises under the agreement. Accordingly, the Company recognizes revenue for the transaction price based upon efforts or inputs to satisfy its performance obligations relative to the total expected inputs. Due to the uncertainty in the achievement of the development and regulatory milestones, the variable consideration associated with these future milestone payments has been fully constrained (excluded) from the transaction price until such time that the Company concludes that it is probable that a significant reversal of previously recognized revenue will not occur. These estimates are re-assessed at each reporting period. Under the Sino Agreement, Sino Biopharma is solely responsible for providing the Company with study drug for the treatment of up to 100 patients, if any, enrolled in a Phase 1 clinical trial for each ARX822 and ARX102, which the Company considers to be noncash consideration. At inception of the agreement, the Company estimated the fair value of noncash consideration. Subsequent changes in the fair value of the noncash consideration, other than those attributable to a change in the form of the noncash consideration, are considered variable consideration and are included in the transaction price. Noncash consideration will be added to the transaction price to the extent a significant revenue reversal in the amount of cumulative revenue recognized will not occur when the uncertainty associated with the noncash consideration is subsequently resolved. Receipt of the study drug is not considered probable of being achieved until enrollment of either or both Phase 1 clinical trials for each of ARX822 and ARX102 commences. Any such adjustments are recorded on a cumulative catch-up basis in the period of adjustment. As of December 31, 2022, the noncash consideration has not been included in the transaction price. Contract Assets and Liabilities Contract balances are as follows as of December 31, (in thousands): 2022 2021 Receivables, included in accounts receivable, net $ 376 $ 1,239 Contract assets, included in prepaid expenses and other current assets $ — $ 149 Contract liabilities, included in deferred revenue, current and $ 1,749 $ 5,648 During the fourth quarter of 2022, the Company recognized milestone revenue of $ 1.0 million from performance obligations satisfied (or partially satisfied) pursuant to the NovoCodex Agreement. During the years ended December 31, 2021 , the Company did no t recognize any revenue from performance obligations satisfied during the period. A reconciliation of the beginning and ending amount of contract liabilities, which are primarily related to the combined performance obligation for the transfer of Company’s license and R&D services and conducting R&D activities, which are a separate performance obligation in the Company’s contracts pursuant to research plans under the agreements, was as follows for the years ended December 31, (in thousands): 2022 2021 Beginning balance $ 5,648 $ 9,731 Recognized as revenue: License fees ( 3,442 ) ( 3,548 ) Reimbursements ( 457 ) ( 535 ) Ending balance $ 1,749 $ 5,648

Share-Based Compensation

Share-Based Compensation	12 Months Ended
	Dec. 31, 2022
Share-Based Payment Arrangement [Abstract]
Share-Based Compensation	11. Share-Based Compensation Share-based compensation expense was as follows for the years ended December 31, (in thousands): 2022 2021 Research and development $ 3,650 $ 9,001 General and administrative 2,603 2,855 Total share-based compensation expense $ 6,253 $ 11,856 On June 17, 2021, upon the closing of the Company’s IPO, options to purchase 7.7 million ordinary shares became fully vested under the original vesting terms, which resulted in $ 6.4 million of share-based compensation expense being recognized in the Company’s consolidated statements of operations and comprehensive loss during the year ended December 31, 2021. 2016 Equity Incentive Plan The Company granted awards under the 2016 Equity Incentive Plan (the 2016 Plan) until June 2021. The terms of the 2016 Plan provided for the grant of incentive share options within the meaning of Section 422 of the Internal Revenue Code of 1986, as amended (the Code), to the Company’s employees and any parent and subsidiary corporations’ employees, and for the grant of non-statutory options and restricted shares to the Company’s employees, directors and consultants, and the Company’s parent and subsidiary corporations’ employees and consultants. The board of directors had the authority to approve the employees and other service providers to whom equity awards were granted and had the authority to determine the terms of each award, subject to the terms of the 2016 Plan, including (i) the number of ordinary shares subject to the award; (ii) when the award became exercisable; (iii) the option or share appreciation right exercise price, which needed to be at least 100 % of the fair market value of the ordinary shares as of the date of grant; and (iv) the duration of the option or share appreciation right (which could not exceed 10 years ). Options granted under the 2016 Plan generally are scheduled to vest over four years , subject to continued service and subject to certain acceleration of vesting provisions. In connection with the adoption of the 2021 Plan (as defined below), the Company terminated the 2016 Plan for future use and provided that no further equity awards are to be granted under the 2016 Plan. All outstanding awards under the 2016 Plan will continue to be governed by their existing terms. 2021 Equity Incentive Plan In June 2021, the Company’s board of directors adopted and the Company’s shareholders approved a 2021 Equity Incentive Plan (the 2021 Plan), and the 2021 Plan became effective June 17, 2021. The 2021 Plan initially provided for the issuance of up to 56,094,909 ordinary shares. The 2021 Plan has an evergreen provision whereby the number of ordinary shares reserved for future issuance will automatically increase on January 1 of each calendar year, beginning on January 1, 2022 through January 1, 2031, in an amount equal to 5 % of the total number of shares of the Company’s share capital outstanding on the last day of the calendar month before the date of each automatic increase, or a lesser number of shares determined by the board of directors. The maximum number of ordinary shares that may be issued upon the exercise of incentive share options under the 2021 Plan is 200,000,000 . Such shares of the Company’s ordinary shares are reserved for issuance to employees, non-employee directors and consultants of the Company. The 2021 Plan provides for the grant of incentive share options, non-incentive share options, and restricted share awards to eligible recipients. Recipients of share options shall be eligible to purchase shares of the Company’s ordinary shares at an exercise price equal to no less than the (estimated) fair market value of such shares on the date of grant. The maximum term of options granted under the Plan is 10 years. Employee option grants generally vest 25 % on the first anniversary of the original vesting commencement date, with the balance vesting monthly over the remaining 3 years . Share options are generally not exercisable prior to the applicable vesting date, unless otherwise accelerated under the terms of the 2016 Plan or 2021 Plan. Although the 2021 Plan provides for options to be issued with an early exercise provision, no options, to date, have been issued with such a right. In addition, the shares to be reserved for issuance under the 2021 Plan will also include shares subject to share options or similar awards granted under the 2016 Plan that expire or terminate without having been exercised in full and shares issued pursuant to awards granted under the Company’s 2016 Plan that are forfeited to or repurchased by the Company. On January 1, 2022, in accordance with the Company’s 2021 Plan, ordinary shares available for issuance under the 2021 Plan increased by 13,506,027 ordinary shares, to 69,600,936 ordinary shares. On January 1, 2023, in accordance with the Company’s 2021 Plan, ordinary shares available for issuance under the 2021 Plan increased by 13,522,762 ordinary shares, to 83,123,698 ordinary shares. The following tables summarizes option activity for the periods presented: Total Weighted- Aggregate Weighted-Average Outstanding as of December 31, 2021 34,200,976 $ 1.43 $ 912 8.1 Granted 17,058,623 $ 0.45 Canceled ( 12,143,425 ) $ 1.08 Outstanding as of December 31, 2022 39,116,174 $ 1.11 $ 1,088 5.4 Vested and exercisable as of 22,083,111 $ 1.34 $ — 4.6 As of December 31, 2021, a total of 18,950,899 vested and exercisable shares were outstanding with a weighted-average exercise price of $ 1.28 per share. There were no options exercised during the year ended December 31, 2022. During the year ended December 31, 2021, 79,212 ordinary shares were issued pursuant to option exercises for gross proceeds of $ 0.1 million. The intrinsic value of options exercised during the year ended December 31, 2021 was $ 0.1 million. As of December 31, 2022, unrecognized compensation expense related to unvested share-based compensation arrangements was $ 9.1 million. These costs are expected to be recognized over a weighted-average term of 3.6 years. Ordinary Share Valuation Prior to completion of the IPO, as there was no public market for the Company’s ordinary shares, the estimated fair value of the Company’s ordinary shares was historically determined by the board of directors as of the date of each option grant, with input from management, considering the most recently available third-party valuation of the Company’s ordinary shares and the board of directors’ assessment of additional objective and subjective factors that it believed were relevant and which may have changed from the date of the most recent third-party valuation through the date of the grant. These third-party valuations were performed in accordance with the guidance outlined in the American Institute of Certified Public Accountants’ Accounting and Valuation Guide, Valuation of Privately-Held Company Equity Securities Issued as Compensation (AICPA Practice Aid) . The AICPA Practice Aid identifies various available methods for allocating the enterprise value across classes or series of capital shares in determining the fair value of the Company’s ordinary shares at each valuation date. After completion of the IPO, the Company’s board of directors determines the fair market value of the ordinary shares based on the closing price of the ADSs as reported on the date of grant on the primary share exchange on which the Company’s ADSs are traded and as converted to the ordinary share price equivalent on the date of grant. Future expense amounts for any particular period may be affected by changes in assumptions or market conditions. The fair value of each option award is estimated on the date of grant using the BSM. The BSM requires the input of subjective assumptions, including the risk-free interest rate, the expected dividend yield of the Company’s ordinary shares, the expected volatility of the price of the Company’s ordinary shares, and the expected term of the option. These estimates involve inherent uncertainties and the application of management’s judgment. If factors change and different assumptions are used, the Company’s share-based compensation expense could be materially different in the future. These assumptions are estimated as follows: Expected Term: The expected term represents the time period options are expected to be outstanding. For options, since the Company does not have sufficient historical experience for determining the expected term of the option awards granted, (i) it determines the expected term assumption for share options using the simplified method, which is an average of the contractual term of the option and its ordinary vesting period and (ii) for options issued out-of-the money or in-the-money, if any, the Company uses the contractual term as the expected term of the options for the expected term assumption. Risk-Free Interest Rate: The risk-free interest rate is based on the implied yield available on U.S. Treasury zero-coupon issues with a term equivalent to that of the expected term of the share-based awards. Expected Volatility: Expected volatility is based on the historical volatilities of industry peers as the Company has only limited trading history for its ordinary shares. The Company intends to continue to consistently apply this process using the same or a similar peer group of public companies, until a sufficient amount of historical information regarding the volatility of the price of its ordinary shares becomes available, or unless circumstances change such that the identified peer companies are no longer similar, in which case other suitable peer companies whose ordinary shares prices are publicly available would be utilized in the calculation. Dividend Yield: The expected dividend yield is based on the Company’s current expectations about its anticipated dividend policy. To date, the Company has not declared any dividends and, therefore, the Company used an expected dividend yield of zero. The weighted-average fair value of options and ESPP (as defined below) awards issued was estimated at the date of grant using the BSM with the following weighted-average assumptions for the years ended December 31: Options ESPP 2022 2021 2022 2021 Expected term (in years) 6.0 6.0 1.2 1.3 Risk-free interest rate 2.9 % 1.0 % 2.8 % 0.2 % Expected volatility 82.0 % 80.5 % 79.2 % 74.6 % Dividend yield — — — — Weighted-average grant date fair value $ 0.31 $ 1.20 $ 0.22 $ 0.78 Option Repricing On January 27, 2023, the compensation committee of the board of directors of the Company approved an option repricing program (the Option Repricing) to permit the Company to reprice certain options to purchase the Company’s ordinary shares held by its employees (including an officer of the Company), non-employee directors and consultants providing services as of January 27, 2023. Under the Option Repricing, eligible options with an exercise price above $ 0.28 per ordinary share (or the equivalent of $ 1.95 per ADS), representing an aggregate of 17,285,155 ordinary shares, or approximately 43 % of the total options outstanding, were amended to reduce such exercise price to $ 0.28 per ordinary share. The Option Repricing will result in additional share-based compensation expense that will be recognized in the Company’s consolidated statements of operations and comprehensive loss in future periods; however, the amount of additional share-based compensation expense and the periods over which it will be recognized have not yet been determined. 2021 Employee Share Purchase Plan In June 2021, the Company’s board of directors adopted and the shareholders approved the Company’s 2021 Employee Share Purchase Plan (the ESPP), which became effective on June 14, 2021. The ESPP allows eligible employees to purchase the Company’s ordinary shares at a discount through payroll deductions of up to 15 % of their eligible compensation, subject to any plan limitations. Initially 3,000,000 ordinary shares have been reserved for issuance under the ESPP. The ESPP has an evergreen provision whereby the number of ordinary shares reserved for future issuance will automatically increase on January 1 of each calendar year, beginning on January 1, 2022 through January 1, 2031 , in an amount equal to 1 % of the total number of shares of the Company’s share capital outstanding on the last day of the calendar month before the date of each automatic increase, or a lesser number of shares determined by the board of directors. The offering periods generally start on December 16 and June 16 of each year and end on December 15 and June 15, respectively, approximately two years later, with each offering containing four separate six month purchase periods. The administrator may, in its discretion, modify the terms of future offerings and purchase periods. The first offering started on the Company’s IPO. On January 1, 2022, in accordance with the Company’s ESPP, ordinary shares available for issuance under the ESPP increased by 2,701,205 ordinary shares, to 5,701,205 ordinary shares. On January 1, 2023, in accordance with the ESPP, ordinary shares available for issuance under the ESPP increased by 2,704,552 ordinary shares, to 8,405,757 ordinary shares. During the year ended December 31, 2022, 334,684 ordinary shares were issued pursuant to the ESPP for gross proceeds of $ 0.1 million. During the year ended December 31, 2021, 105,329 ordinary shares were issued pursuant to the ESPP for gross proceeds of $ 0.1 million. The ESPP was suspended indefinitely, effective December 16, 2022, and as of December 31, 2022 there was no unrecognized share-based compensation expense related to the ESPP.

Defined Contribution Plan

Defined Contribution Plan	12 Months Ended
	Dec. 31, 2022
Retirement Benefits [Abstract]
Defined Contribution Plan	12. Defined Contribution Plan The Company established a defined contribution savings plan under Section 401(k) of the Internal Revenue Code (the 401(k) Plan). The 401(k) Plan covers substantially all employees who meet minimum age and service requirements and allows participants to defer a portion of their annual compensation on a pre-tax basis. Matching contributions to the 401(k) Plan may be made at the discretion of the Company’s board of directors. During the years ended December 31, 2022 and 2021, the Company made discretionary contributions of $ 0.4 million and $ 0.3 million, to the 401(k) Plan, respectively.

Income Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2022
Income Tax Disclosure [Abstract]
Income Taxes	13. Income Taxes Loss before income taxes was as follows for the years ended December 31, (in thousands): 2022 2021 U.S. operations $ ( 73,132 ) $ ( 61,541 ) Non-U.S. operations ( 2,927 ) ( 6,746 ) Loss before provision for income taxes $ ( 76,059 ) $ ( 68,287 ) The components of the provision for income taxes was as follows for the years ended December 31, (in thousands): 2022 2021 Current: U.S. $ — $ — State and local 1 1 Foreign 1,936 — Total current 1,937 1 Deferred: U.S. — — Total deferred — — Total provision for income taxes $ 1,937 $ 1 A reconciliation of the Company’s statutory income tax rate to the Company’s effective income tax rate for the years ended December 31, was as follows: 2022 2021 Income tax benefit at Cayman statutory rate 0.00 % 0.00 % U.S. and non-U.S. rate differential 21.57 % 19.49 % State taxes 4.77 % 3.94 % R&D credits 0.73 % 3.00 % Change in valuation allowance ( 27.61 %) ( 25.79 %) Share-based compensation ( 3.62 %) ( 0.66 %) Ambrx Shanghai reorganization 1.77 % 0.00 % Other, net ( 0.16 %) 0.02 % Effective tax rate ( 2.55 %) ( 0.00 %) A valuation allowance has been established as realization of deferred tax assets has not met the more likely-than-not threshold requirement. If the Company’s judgment changes and it is determined that the Company will be able to realize these deferred tax assets, the tax benefits relating to any reversal of the valuation allowance on deferred tax assets as of December 31, 2022, will be accounted for as a reduction to income tax expense. During the years ended December 31, 2022 and 2021, the change in the valuation allowance from prior year was an increase of $ 20.6 million and $ 17.6 million, respectively. Significant components of the Company’s deferred tax assets as of December 31, are shown below (in thousands): 2022 2021 Deferred tax assets: Net operating loss carryforwards $ 57,647 $ 48,179 R&D credits 16,385 14,317 Capitalized R&D 8,980 — Lease liabilities 3,110 3,662 Share-based compensation 1,219 3,223 Deferred revenues 454 1,575 Intangible assets 337 — Other 945 1,047 Total deferred tax assets 89,077 72,003 Deferred tax liabilities: IPR&D ( 5,436 ) ( 5,841 ) Right-of-use assets ( 2,847 ) ( 3,553 ) Intangible assets — ( 2,445 ) Total deferred tax liabilities ( 8,283 ) ( 11,839 ) Net deferred tax assets 80,794 60,164 Less: valuation allowance ( 81,674 ) ( 61,044 ) $ ( 880 ) $ ( 880 ) As of December 31, 2022, the Company had U.S. federal, state and foreign net operating loss carryforwards of approximately $ 103.5 million, $ 136.2 million and $ 13.7 million, respectively which will begin to expire in 2025 , 2028 and 2023 , respectively, unless previously utilized. Additionally, as of December 31, 2022, the Company also had U.S. federal and foreign net operating loss carryforwards of approximately $ 107.1 million and $ 1.7 million, respectively, which can be carried forward indefinitely. As of December 31, 2022, the Company also had U.S. federal R&D tax credit carryforwards of approximately $ 12.3 million which will begin to expire in 2024 unless previously utilized. As of December 31, 2022, the Company had state tax credit carryforwards of approximately $ 8.9 million, which can be carried forward indefinitely. Pursuant to Internal Revenue Code (IRC) Sections 382 and 383, use of the Company’s net operating loss and R&D income tax credit carryforwards may be limited in the event of a future cumulative change in ownership of more than 50.0% within a three-year period. The Company completed an analysis under IRC Sections 382 and 383 through June 2015 and determined the Company’s U.S. net operating losses and R&D credit carryforwards may be limited due to changes in ownership in 2015. The analysis determined that substantially all net operating losses and R&D credit carryforwards could be utilized before expiration. No analysis under IRC Sections 382 and 383 has been completed for tax years 2016 through 2022. Future changes in the Company’s stock ownership, which may be outside of its control, may trigger an “ownership change.” In addition, future equity offerings or acquisitions that have equity as a component of the purchase price could result in an “ownership change.” If an “ownership change” has occurred or does occur in the future, an annual limitation in IRC Sections 382 and 383 could result in the expiration of net operating loss and tax credit carryforwards before utilization; however, there is no tax impact as a result of the full valuation allowance on tax attributes. The Tax Cuts and Jobs Act resulted in significant changes to the treatment of R&D expenditures under Section 174. For tax years beginning after December 31, 2021, taxpayers are required to capitalize and amortize all R&D expenditures that are paid or incurred in connection with their trade or business. Specifically, costs for U.S.-based R&D activities must be amortized over five years and costs for foreign R&D activities must be amortized over fifteen years , both using a midyear convention. During the year ended December 31, 2022, the Company capitalized $ 49.5 million of R&D expenses. As of December 31, 2022, the Company had liabilities for uncertain tax positions of $ 4.7 million, of which, if recognized, $ 3.3 million would not impact the Company’s tax position and effective income tax rate due to a full valuation allowance. The Company’s policy is to record interest and penalties related to income taxes as part of its income tax provision. As of December 31, 2022, the Company has accrued penalties of $ 0.2 million related to uncertain tax positions. A reconciliation of the beginning and ending amount of unrecognized tax benefits was as follows (in thousands): December 31, 2022 2021 Beginning balance $ 2,767 $ 2,282 Additions based on tax positions related to the current year 1,958 485 Ending balance $ 4,725 $ 2,767 The Company is subject to taxation in the United States, California, China, and Australia. The Company is subject to income tax examination by tax authorities in the United States in tax years 2005 to 2022 due to its net operating losses. In China, the Company is subject to income tax examinations by tax authorities for its 2018 to 2022 tax years. In Australia, the Company is subject to income tax examinations by tax authorities for its 2020 to 2022 tax years.

Related Party Transactions

Related Party Transactions	12 Months Ended
	Dec. 31, 2022
Related Party Transactions [Abstract]
Related Party Transactions	14. Related Party Transactions In the ordinary course of business, the Company has related party transactions with affiliates of a noncontrolling shareholder. The following tables present the Company’s activities with affiliates of the noncontrolling shareholders (in thousands): December 31, 2022 2021 Balances: Prepaid R&D expenses $ 14 $ 55 Accounts payable $ 352 $ 167 Accrued liabilities $ 99 $ 250 Years Ended December 31, 2022 2021 Year-to-date activity: Amounts paid $ 776 $ 515 R&D expense recognized $ 146 $ 520

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2022
Accounting Policies [Abstract]
Use of Estimates	Use of Estimates The preparation of consolidated financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the consolidated financial statements and the reported amounts of revenues and expenses during the reporting period. On an ongoing basis, the Company evaluates its estimates, including those related to the valuation of share-based awards, MDS, and other fair value measurements, the discount rate used in estimating the present value of the right-of-use (ROU) assets and lease liabilities, the useful lives of property and equipment and intangible assets, the recoverability of long-lived assets, clinical trial accruals, periods over which revenue should be recognized, deferred income taxes and related valuation allowances, and the assessment of the Company’s ability to fund its operations for at least the next 12 months from the date of issuance of these consolidated financial statements. The Company bases its estimates on historical experience and other market-specific or other relevant assumptions that it believes to be reasonable under the circumstances. Estimates are assessed each reporting period and updated to reflect current information. As future events and their effects cannot be determined with precision, actual results may materially differ from those estimates or assumptions. Due to the recent disruption in access to bank deposits and lending commitments due to bank failures, the COVID-19 pandemic and macroeconomic and geopolitical conditions, there has been uncertainty and disruption in the global economy and financial markets. The Company is not aware of any specific event or circumstance that would require an update to its estimates or judgments or a revision of the carrying value of its assets or liabilities as of December 31, 2022. While there was no material impact to the Company’s consolidated financial statements as of and for the year ended December 31, 2022, these estimates may change, as new events occur and additional information is obtained, which could materially impact the Company’s consolidated financial statements in future reporting periods.
Segment Reporting	Segment Reporting Operating segments are identified as components of an enterprise about which separate discrete financial information is available for evaluation by the chief operating decision-maker, who is the Chief Executive Officer of the Company, in making decisions regarding resource allocation and assessing performance. The Company views its operations and manages its business in one operating segment.
Risk and Uncertainties	Risk and Uncertainties Since December 2019, COVID-19, a novel strain of coronavirus has become a global pandemic. The virus continues to spread globally, has been declared a pandemic by the World Health Organization and has spread to over 100 countries, including the United States. The impact of this pandemic has been and will likely continue to be extensive in many aspects of society, which has resulted in and will likely continue to result in significant disruptions to the global economy, as well as businesses and capital markets around the world. The full extent to which the COVID-19 pandemic will directly or indirectly impact the Company’s business, results of operations and financial condition, including expenses, clinical trials and other costs, will depend on future developments that are highly uncertain, including as a result of new information that may emerge concerning COVID-19 and the actions taken to contain or treat COVID-19, as well as the economic impact on local, regional, national and international markets.
Concentrations of Credit Risk	Concentrations of Credit Risk Financial instruments that potentially subject the Company to significant concentrations of credit risk consist primarily of cash and cash equivalents, restricted cash, MDS, and accounts receivable which are generally not collateralized. Deposits in the Company’s checking and money market accounts are maintained in federally insured financial institutions and are subject to federally insured limits or limits set by the Securities Investor Protection Corporation. In addition, the Company maintains cash and cash equivalents in foreign bank accounts, which are not federally insured. The Company attempts to minimize credit risk associated with its cash and cash equivalents by periodically evaluating the credit quality of its primary financial institutions. The Company’s investment portfolio is maintained in accordance with its investment policy, which is designed to preserve capital, safeguard funds and limit exposure to risk. While the Company maintains cash deposits in FDIC insured financial institutions in excess of federally insured limits, it does not believe that it is exposed to significant credit risk due to the financial position of the depository institutions in which those deposits are held. The Company has not experienced any losses on such accounts. During the year ended December 31, 2022, revenues from the Company’s top two customers represented 65.9 % and 25.6 % of total revenues, respectively. During the year ended December 31, 2021, revenues from the Company’s top two customers represented 56.8 % and 35.8 % of total revenues, respectively. As of December 31, 2022, billed accounts receivable for two customers represented 78.4 % and 11.8 % of total billed receivables, respectively. As of December 31, 2021, billed accounts receivable for two customers represented 74.6 % and 21.3 % of total billed receivables, respectively.
Cash, Cash Equivalents and Restricted Cash	Cash, Cash Equivalents and Restricted Cash Cash and cash equivalents consist of readily available cash in checking accounts, money market funds and other MDS with original maturities of three months or less. The following table provides a reconciliation of cash, cash equivalents and restricted cash, reported within the consolidated statements of cash flows for the years ended December 31, (in thousands): 2022 2021 Cash and cash equivalents $ 55,610 $ 170,064 Restricted cash 831 842 Total cash, cash equivalents, and restricted cash presented in the $ 56,441 $ 170,906 As of December 31, 2022 and 2021 , the Company’s restricted cash consists of cash related to the Company’s clinical trials.
Accounts Receivable, Net	Accounts Receivable, Net Accounts receivable, net, are recorded net of any allowance for current expected credit losses measured based on historical experience, current conditions, and reasonable and supportable forecasts. As of December 31, 2022 and 2021 , the Company has determined an allowance for expected credit losses is not material.
Contract Balances	Contract Balances The timing of revenue recognition, billings and cash collections results in billed accounts receivable, unbilled receivables (contract assets) and deferred revenue (contract liabilities) on the consolidated balance sheet, recorded on a contract-by-contract basis at the end of each reporting period. The majority of the Company’s contract amounts are invoiced as work progresses in accordance with agreed-upon contractual terms, either at periodic intervals or upon achievement of contractual milestones. Billing sometimes occurs subsequent to revenue recognition, resulting in contract assets. These contract assets are referred to as unbilled receivables and are reported within prepaid expenses and other current assets on the consolidated balance sheets. Unbilled receivables are transferred to accounts receivables, net, when the Company’s right of receipt becomes unconditional. Contract liabilities from the Company’s R&D agreements (R&D Agreements) arise when amounts invoiced to customers exceed revenues recognized based upon measure of progress achieved. Contract liabilities additionally include advanced payments from customers on certain contracts. Contract liabilities decrease as the Company recognizes revenue from the satisfaction of the related performance obligation. Contract liabilities are included in deferred revenue, current portion and deferred revenue, net of current portion, on the consolidated balance sheets.
Marketable Debt Securities, Available-for-Sale	Marketable Debt Securities, Available-for-Sale The Company’s MDS portfolio, which is classified as available-for-sale, is comprised of money market funds, commercial paper, U.S. government securities, debt securities of U.S. financial institutions, corporate debt and asset backed securities. The objective of the Company’s investment policy is to preserve capital and maintain liquidity, with acceptable levels of risk. The investment policy limits interest-bearing security investments to certain types of debt and money market instruments issued by institutions with investment grade credit ratings, and it places restrictions on maturities and concentrations by asset class and issuer. MDS are classified as either current or non-current assets in the consolidated balance sheets based on each instrument's underlying contractual maturity date. Generally, at the time of purchase, MDS with remaining maturities of greater than three months and less than 12 months are classified as current assets and MDS with remaining maturities greater than 12 months for which the Company has the intent and ability to hold the investment for greater than 12 months are classified as non-current assets. The Company may sell certain of its MDS prior to their stated maturities for strategic purposes or in anticipation of credit deterioration. The Company’s MDS are stated at fair value, with unrealized gains and losses, net of tax, if any, reported in accumulated other comprehensive loss in the consolidated balance sheets, until disposition or maturity. Dividend and interest income, amortization/accretion of premiums and discounts, and realized gains and losses, which are determined using the specific identification method, are recognized in investment income, net, in the consolidated statements of operations and comprehensive loss. MDS are subject to a periodic impairment review. If the Company does not intend to sell and it is not more likely than not that it will be required to sell the security prior to recovery of its amortized cost basis, the Company will determine whether a decline in fair value below the amortized cost basis is due to credit-related factors. The credit loss is measured as the amount by which the debt security's amortized cost basis exceeds the estimate of the present value of cash flows expected to be collected, up to the difference between the amortized cost basis and the fair value. Impairment is assessed at the individual security level. Credit-related impairment is recognized as an allowance in the consolidated balance sheets with a corresponding adjustment to investment income, net, in the consolidated statements of operations and comprehensive loss. Any impairment that is not credit-related is recognized in accumulated other comprehensive loss in the consolidated balance sheets. The Company does not separately measure an allowance for credit losses on accrued interest receivables on its MDS. The Company writes off accrued interest receivables by reversing interest income in the period deemed uncollectible in investment income, net, in the Company’s consolidated statements of operations and comprehensive loss. Any accrued interest receivable on MDS is recorded in prepaid expenses and other current assets in the consolidated balance sheets.
Property and Equipment, Net	Property and Equipment, Net Property and equipment is recorded at cost and depreciated over the estimated useful lives of the assets using the straight-line method. Leasehold improvements are stated at cost and are amortized on a straight-line basis over the lesser of the remaining term of the related lease or the estimated useful lives of the assets. Repairs and maintenance costs are charged to expense as incurred and improvements and betterments are capitalized. Depreciation is calculated over their estimated useful lives as follows: Laboratory equipment 5 years Computer, software and office equipment 3 - 8 years Furniture and fixtures 5 years The useful lives of the Company’s assets are reviewed annually. When assets are retired or otherwise disposed of, the cost and accumulated depreciation are removed from the consolidated balance sheets and any resulting gain or loss is reflected in the consolidated statements of operations and comprehensive loss in the period realized.
Intangible Assets, Net	Intangible Assets , Net The Company records its intangible assets based on their fair values at the date of acquisition. The Company’s finite lived intangible assets related to acquired technologies has estimated remaining useful lives between three to 12 years as of December 31, 2022, and four to 13 years as of December 31, 2021. Amortization expense for the Company’s finite lived intangible assets is charged to research and development expense in the consolidated statements of operations and comprehensive loss on a straight-line basis over the assets’ estimated useful lives. Impairment losses on finite-lived intangible assets are recorded when indicators of impairment are present and the undiscounted cash flows estimated to be generated by those assets are less than the assets’ carrying amount. If such assets are considered impaired, the impairment to be recognized is measured by the amount by which the carrying amount of the assets exceeds the estimated fair value of the assets. During the fourth quarter of 2021, the Company determined the estimated undiscounted future cash flows of one of its acquired technology intangible assets was less than its carrying value and therefore recorded an impairment charge of $ 0.5 million. In the first quarter of 2022, the Company received a Notice of Termination of Collaboration and License agreement (Relaxin) between Bristol-Myers Squibb Company (BMS) and the Company (the Relaxin Agreement) from BMS to be effective three months from receipt of the notification. Due to this termination notice and the Company’s determination that the asset had no alternative future use, the Company concluded the net carrying value of the BMS Relaxin intangible asset was greater than its estimated fair value and therefore recorded an impairment charge of $ 2.5 million. In the second quarter of 2022, the Company received verbal notification from BMS of its intent to terminate the Collaboration and License Agreement (FGF-21) between BMS and the Company (the FGF-21 Agreement), which was followed by a formal notification on July 18, 2022 to be effective three months from receipt of the formal notification date. Due to this termination notice and the Company’s determination that the asset had no alternative future use, the Company concluded the net carrying value of the BMS FGF-21 intangible asset was greater than its estimated fair value and therefore recorded an impairment charge of $ 7.2 million. The Company’s intangible assets also include acquired in-process research and development (IPR&D) from a business combination, which is recognized as an indefinite lived intangible asset until completion or abandonment of the related R&D activities. When the related R&D activity is completed, the IPR&D intangible asset is reclassified as a finite-lived intangible asset and amortized over the remaining useful life. The Company’s acquired IPR&D is tested for impairment annually or more frequently if events or changes in circumstances between annual tests indicate that the asset may be impaired. On October 18, 2022, the Company announced a reprioritization of its product pipeline after conducting a strategic assessment that considered its cash runway and its product pipeline near term value creation opportunities, among other factors. As a result of this assessment, the Company paused its internal development of ARX788 and, among other potential activities, indicated it will seek development partners to further the development of ARX788 outside of China. The Company determined this reprioritization was a qualitative trigger of potential impairment of its IPR&D asset and had a quantitative analysis completed as of the reprioritization date. The quantitative analysis determined the IPR&D asset was not impaired as of the reprioritization date. The Company’s annual impairment test for the years ended December 31, 2022 and 2021, performed in the fourth quarter, did not result in additional impairment losses related to its intangible assets. While the Company’s current and historical operating losses and negative cash flows are possible indicators of impairment, management believes future cash flows to be generated by its remaining long-lived assets support the carrying value.
Fair Value of Financial Instruments	Fair Value of Financial Instruments The Company’s financial instruments consist primarily of cash and cash equivalents, MDS, accounts receivable, accounts payable and accrued liabilities. The carrying amounts of cash and cash equivalents, accounts receivable, accounts payable and accrued liabilities are considered to be representative of their respective fair values because of the relatively short-term nature of those instruments. The accounting guidance defines fair value, establishes a consistent framework for measuring fair value and expands disclosure for each major asset and liability category measured at fair value on either a recurring or nonrecurring basis. Fair value is defined as an exit price, representing the amount that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants. As such, fair value is a market-based measurement that should be determined based on assumptions that market participants would use in pricing an asset or liability. As a basis for considering such assumptions, the accounting guidance establishes a three-tier fair value hierarchy, which prioritizes the inputs used in measuring fair value as follows: Level 1: Inputs based on quoted market prices for identical assets or liabilities in active markets at the measurement date. Level 2: Observable inputs other than quoted prices included in Level 1, such as quoted prices for similar assets and liabilities in active markets; quoted prices for identical or similar assets and liabilities in markets that are not active; or other inputs that are observable or can be corroborated by observable market data. Level 3: Inputs which reflect management’s best estimate of what market participants would use in pricing the asset or liability at the measurement date. The inputs are unobservable in the market and significant to the instrument’s valuation. Assets and liabilities are classified based on the lowest level of input that is significant to the fair value measurements. The Company reviews the fair value hierarchy classification on a quarterly basis.
Clinical Trial Accruals	Clinical Trial Accruals As part of the process of preparing the consolidated financial statements, the Company is required to estimate expenses resulting from obligations under contracts with vendors, clinical research organizations, consultants and under clinical site agreements relating to conducting clinical trials. The financial terms of these contracts vary and may result in payment flows that do not match the periods over which materials or services are provided under such contracts. The Company’s objective is to reflect the appropriate clinical trial expenses in its consolidated financial statements by recording those expenses in the period in which services are performed and efforts are expended. The Company accounts for these expenses according to the progress of the clinical trial as measured by patient progression and the timing of various aspects of the clinical trial. Management determines accrual estimates, as of each balance sheet date, through discussions with applicable personnel and outside service providers as to the progress of clinical trials. During a clinical trial, the Company adjusts its expense recognition if actual results differ from previous estimates.
Leases	Leases The Company determines if an arrangement is a lease at the inception of the contract. The asset component of the Company’s operating leases is recorded as a ROU asset and the liability component is recorded as current portion of operating lease liabilities and operating lease liabilities, net of current portion, in the consolidated balance sheets. At the commencement, reassessment or modification date, the cost of the ROU asset includes all the following, if any: the amount of the initial measurement of the lease liability, any lease payments made to the lessor at or before the commencement date minus any lease incentive received and any initial direct costs incurred by the lessee. Operating lease liabilities are recognized based on the present value of lease payments over the lease term at the commencement date. The Company uses an incremental borrowing rate based on the information available at commencement date in determining the present value of lease payments if an implicit rate of return is not provided within the lease contract. When evaluating its incremental borrowing rate, management considers its borrowing rate on external collateralized debt with a term commensurate with the lease term, if any, or in the absence of external debt, the average incremental borrowing rate of its peer group. These amounts are estimated at the inception of or upon reassessment of a lease arrangement. Lease cost is recognized on a straight-line basis over the lease term, and includes amounts related to short-term leases. Variable lease costs, such as common area maintenance, real estate taxes and management fees which do not depend on an index or rate are recognized as incurred. Short-term leases of 12 months or less are expensed as incurred, which approximates the straight-line basis due to the short-term nature of the leases. The Company has elected not to separate lease and non-lease components. ROU assets and operating lease liabilities are remeasured upon lease reassessment using the present value of remaining lease payments and estimated incremental borrowing rates. The Company reviews any changes to its lease agreements for potential modifications and/or indicators of impairment of the respective ROU asset.
Short-Term Leases	Short-term leases of 12 months or less are expensed as incurred, which approximates the straight-line basis due to the short-term nature of the leases. The Company has elected not to separate lease and non-lease components.
Revenue Recognition	Revenue Recognition The Company determines revenue recognition for arrangements within the scope of ASC Topic 606, Revenue from Contracts with Customers (ASC 606) by performing the following five steps: (i) identify the contract; (ii) identify the performance obligations in the contract; (iii) determine the transaction price; (iv) allocate the transaction price to the performance obligations in the contract; and (v) recognize revenue when, or as, the Company satisfies a performance obligation. A performance obligation is a promise in a contract to transfer a distinct good or service and is the unit of accounting in ASC 606. A contract’s transaction price is allocated among each distinct performance obligation based on relative standalone selling price and recognized as revenue when, or as, the applicable performance obligation is satisfied. The terms of the Company’s R&D Agreements include upfront fees, R&D funding or reimbursements, milestone and other contingent payments for the achievement of defined objectives and certain preclinical, clinical, regulatory and sales-based events, as well as royalties on sales of commercialized products. Agreements with certain upfront payments may require deferral of revenue recognition to a future period until the Company performs the obligations under these agreements. The Company uses the most likely amount method to estimate variable consideration for event-based milestones and other contingent payments and have been fully constrained given the degree of uncertainty around the occurrence of such events. The Company continues to re-evaluate the transaction price in each reporting period as contingencies are resolved and other changes in circumstances occur. The Company is required to adjust the transaction price for the effects of the time value of money if the timing of payments agreed to by the parties to the contract, explicitly or implicitly, provides the Company or its customer with a significant benefit of financing the transfer of goods or services. The Company concluded that its contracts with the customers do not contain a significant financing component because the payment structure of the R&D Agreements arises from reasons other than providing a significant benefit of financing. Taxes assessed by a governmental authority that are both imposed on and concurrent with a specific revenue-producing transaction, that are collected by the Company from a customer, are excluded from revenues.
R&D Agreements	R&D Agreements The Company analyzes its R&D Agreements to assess whether they are within the scope of ASC Topic 808, Collaborative Arrangements (ASC 808), which includes determining whether such arrangements involve joint operating activities performed by parties that are both active participants in the activities and exposed to significant risks and rewards dependent on the commercial success of such activities. This assessment is performed at contract inception and again, if changes in either the roles of the participants in the arrangement or the participants’ exposure to significant risks and rewards dependent on the ultimate commercial success of the arrangement are identified. For each of the periods presented, the Company determined that its contracts with customers do not fall within the guidance in ASC 808 as the Company is not exposed to significant risks that are dependent on commercial success of the collaborative activity.
License Fees	License Fees As part of the R&D Agreements, the Company licenses its intellectual property to customers for fees, which many times includes the receipt of upfront fees. If a license to the Company’s intellectual property is determined to be distinct from the other promises or performance obligations identified in the agreement, the Company recognizes revenue from non-refundable, upfront fees allocated to the license when the license is transferred to the customer. In assessing whether a promise or performance obligation is distinct from the other promises, the Company considers factors such as the research, development, manufacturing and commercialization capabilities of the licensee and the availability of the associated expertise in the general marketplace. In addition, the Company considers whether the licensee can benefit from a promise for its intended purpose without the receipt of the remaining promise, whether the value of the promise is dependent on the unsatisfied promise, whether there are other vendors that could provide the remaining promise, and whether it is separately identifiable from the remaining promise. For licenses that are combined with other promises, the Company utilizes judgment to assess the nature of the combined performance obligation to determine whether the combined performance obligation is satisfied over time or at a point in time and, if over time, the appropriate method of measuring progress for purposes of recognizing revenue. For those license related performance obligations that are satisfied over time, the Company measures progress through actual effort, including hours incurred, and an estimation of time to completion based on the budget and research workplan. Typical agreements require the transfer of knowledge so the customer can effectively use the license and the Company believes these measurements accurately represent the transfer of knowledge through its clinical research services. The Company evaluates the measure of progress each reporting period and, if circumstances change over time, the Company will update its measure of progress to reflect any changes in the outcome of the performance obligation and, therefore, adjust the measure of performance and related revenue recognition. The measure of progress, and thereby periods over which revenue should be recognized, is subject to estimates by management and may change over the course of the agreement. Such a change could have a material impact on the amount of revenues the Company records in future periods. During the second half of 2021, the Company re-evaluated the measure of progress for a compound under one of its R&D Agreements, which resulted in an increased estimate in the timing and efforts of satisfaction of the Company’s performance obligations under the agreement. This change did not have an impact on the transaction price and/or the variable consideration to be received under the agreement. As a result of the re-evaluation, the Company recognized a cumulative catch-up adjustment reducing revenue by approximately $ 1.4 million with an equal increase in total contract liabilities (i.e., deferred revenue) from upfront payments as of December 31, 2021. The Company’s periodic reassessments, during the year ended December 31, 2022 , did not result in any adjustments to its current revenue recognition methodology.
Reimbursements	Reimbursements As part of the R&D Agreements where the Company only provides R&D services, the Company is reimbursed by the customer for certain costs incurred as agreed to in the research plan. The Company elected the practical expedient for certain R&D reimbursements which allows it to recognize revenue in the amount for which the Company has a right to invoice if its right to consideration is an amount corresponding directly to the value of completed performance to date. The Company estimates variable consideration, if any, at contract inception and each reporting period, to determine if there were any changes in the transaction price. The transaction price will be adjusted to the extent the risk of significant revenue reversal in the amount of cumulative revenue recognized will not occur when the uncertainty associated with the milestones are subsequently resolved. Any such adjustments are recorded on a cumulative catch-up basis and revenues and earnings are impacted in the period of adjustment.
Milestones and Other Contingent Payments	Milestones and Other Contingent Payments At the inception of each R&D Agreement that includes milestones and other contingent payments, the Company evaluates whether the milestones or other contingent payments are considered probable of being achieved and estimates the amount to be included in the initial transaction price using the most likely amount method. If it is probable that a significant revenue reversal would not occur, the associated value is included in the transaction price. Milestones or other contingent payments are only included in the transaction price to the extent the risk of a significant revenue reversal in the amount of cumulative revenue recognized will not occur when the uncertainty associated with the milestones are subsequently resolved. The Company evaluates factors such as the scientific, clinical, regulatory, commercial, and other risks that must be overcome to achieve the particular contingency in making this assessment. There is considerable judgment involved in determining whether it is probable that a significant revenue reversal would not occur. At the end of each subsequent reporting period, the Company reevaluates the probability of achievement of all milestones and other contingencies subject to constraint and, if necessary, adjusts its estimate of the overall transaction price. Any such adjustments are recorded on a cumulative catch-up basis and revenues and earnings are impacted in the period of adjustment.
Sales-Based Milestones and Royalties on Sales of Commercialized Products	Sales-Based Milestones and Royalties on Sales of Commercialized Products For R&D Agreements that include sales-based milestone payments and royalties which are the result of a customer-vendor relationship and for which the license is deemed to be the predominant item to which the royalties relate, the Company recognizes revenue at the later of (i) when the related sales occur, or (ii) when the performance obligation to which some or all of the royalty has been allocated has been satisfied or partially satisfied.
R&D Services	R&D Services Promises under the Company’s R&D Agreements may include R&D services to be performed by the Company on behalf of the counterparty. If these services are determined to be distinct from the other promises or performance obligations identified in the arrangement, the Company recognizes the transaction price allocated to these services as revenue over time based on an appropriate measure of progress of the performance. If these services are determined not to be distinct from the other promises or performance obligations identified in the arrangement, the Company recognizes the transaction price allocated to the combined performance obligation as the related performance obligation is satisfied. For those R&D services that are satisfied over time, the Company, measures progress through actual effort, including hours incurred, and an estimation of time to completion based on the budget and research workplan. Typical agreements require the transfer of knowledge and development of drug products and the Company believes these measurements accurately represent the transfer of clinical research services.
Customer Options	Customer Options If an arrangement contains customer options, the Company evaluates whether the options are material rights because they allow the customer to acquire additional goods or services for free or at a discount incremental to the range of discounts typically given to a similar class of customers. If the customer options are determined to represent a material right, the material right is recognized as a separate performance obligation at the outset of the arrangement. The Company allocates the transaction price to material rights based on the relative stand-alone selling price, which is determined based on the identified discount and the probability that the customer will exercise the option. Amounts allocated to a material right are not recognized as revenue until, at the earliest, the future goods or services are transferred or upon expiration of the option. If the options are deemed not to be a material right, they are excluded as performance obligations at the outset of the arrangement.
Research and Development Expense	Research and Development Expense R&D expenses consist primarily of costs incurred in connection with the development of the Company’s technology platform, product candidates, discovery efforts and preclinical and clinical development of its product candidates. The Company’s research and development expenses include third-party costs with contract research organizations, contract manufacturing organizations and others conducting R&D activities and clinical trials on the Company’s behalf, manufacturing costs, outside consultant costs, laboratory supply and clinical trial material costs, and license payments for intellectual property used in R&D activities. The Company’s R&D expenses also include personnel costs, such as salaries, benefits, and other employee related costs, including share-based compensation, for personnel engaged in the Company’s R&D functions, amortization of finite-lived intangible assets, facility and equipment related costs, which include depreciation and amortization costs and expenses for rent and maintenance of facilities and other operating costs if specifically identifiable to R&D activities.
General and Administrative Expense	General and Administrative Expense General and administrative (G&A) expenses include personnel costs, such as salaries and other related costs, including share-based compensation, for personnel in the Company’s executive, finance, business development, information technology, human resources, operations and administrative functions. G&A expenses also include legal fees relating to intellectual property and corporate matters, professional fees for accounting, auditing, tax and consulting services, insurance costs, travel expenses, facilities-related costs, which include depreciation costs and expenses for rent and maintenance of facilities, and other operating costs that are not specifically attributable to research activities.
Patent Expenses	Patent Expenses The Company expenses all patent costs as incurred in connection with patent applications, including direct application fees, and the legal and consulting expenses related to making such applications, and such costs are included in G&A expenses in the consolidated statements of operations and comprehensive loss.
Share-Based Compensation	Share-Based Compensation The Company accounts for share-based compensation under the provisions of ASC Topic 718, Compensation—Stock Compensation . The Company estimates the fair value of each option award on the date of grant using the Black-Scholes option pricing model (BSM). The BSM requires the use of highly subjective assumptions, including, but not limited to, expected share price volatility over the term of the awards and the expected term of the options. The Company recognizes share-based compensation expense on a straight-line basis based upon the grant date fair value. For awards whose vesting is based upon satisfaction of both a requisite service period and a performance criterion, the Company records share-based compensation expense on a straight-line basis until the earlier of the completion of the explicit service period or the achievement of the performance criteria. Performance criteria for awards subject to regulatory approval do not become probable of occurrence until the board of director’s reviews and approves the satisfaction of the performance criteria. The Company recognizes the effect of forfeitures in compensation cost in the period that the award was forfeited. See Note 11—Share-Based Compensation for information on the assumptions used in determining the grant date fair value.
Income Taxes	Income Taxes The Company uses the asset and liability method of accounting for income taxes. Under this method, deferred tax assets and liabilities are determined based on the difference between the financial reporting and the tax reporting basis of assets and liabilities and are measured using the enacted tax rates and laws that are expected to be in effect when the differences are expected to reverse. The Company provides a valuation allowance against net deferred tax assets unless, based upon the available evidence, it is more likely than not that the deferred tax assets will be realized. When the Company establishes or reduces the valuation allowance against its deferred tax assets, its provision for income taxes will increase or decrease, respectively, in the period such determination is made. The accounting guidance for uncertainty in income taxes prescribes a recognition threshold and measurement attribute criteria for the financial statement recognition and measurement of tax positions taken or expected to be taken in a tax return. For those benefits to be recognized, a tax position must be more likely than not to be sustained upon examination by taxing authorities based on the technical merits of the position. Interest and penalties, if any, related to unrecognized income tax positions are recognized in provision for income taxes, in the consolidated statements of operations and comprehensive loss.
Net Loss Per Share Attributable to Ambrx Biopharma Inc Ordinary Shareholders	Net Loss Per Share Attributable to Ambrx Biopharma Inc Ordinary Shareholders Basic net loss per ordinary share is calculated by dividing the net loss attributable to ordinary Ambrx shareholders by the weighted-average number of ordinary shares outstanding during the period, without consideration for potentially dilutive securities. Diluted net loss per share is computed by dividing the net loss attributable to ordinary shareholders by the weighted-average number of ordinary shares and potentially dilutive securities outstanding for the period determined using the treasury-stock and if-converted methods. For purposes of the diluted net loss per share calculation, potentially dilutive securities are excluded from the calculation of diluted net loss per share because their effect was anti-dilutive and therefore, basic and diluted net loss per share were the same for all periods presented. Potentially dilutive securities excluded from the calculation of diluted net loss per share included options to purchase 39,116,174 and 34,200,976 ordinary shares for the years ended December 31, 2022 and 2021 , respectively.
Foreign Currency	Foreign Currency The functional currency of Ambrx HK, Ambrx US and Ambrx AU is the U.S. dollar. Through June 30, 2021, the functional currency for Ambrx Shanghai was the Chinese Renminbi. The financial statements of Ambrx Shanghai were translated into U.S. dollars using exchange rates in effect at each period-end for assets and liabilities and average exchange rates during the period for results of operations. Upon completion of the Reorganization, Ambrx Shanghai became the Company’s wholly owned subsidiary at which time their functional currency became the U.S. dollar. The adjustment resulting from translating the financial statements of the Company’s then majority-owned subsidiary was reflected in accumulated other comprehensive loss in the Company’s consolidated balance sheets. Foreign currency transaction gains and losses are reported as other income (expense), net, in the consolidated statements of operations and comprehensive loss. Foreign currency transaction gains and losses during the years ended December 31, 2022 and 2021 , were not material.
Noncontrolling Interests	Noncontrolling Interests Through March 31, 2021, revenues, expenses, gains, losses, net loss and other comprehensive loss were reported in the consolidated financial statements at the consolidated amounts, which included the amounts attributable to both the controlling and redeemable noncontrolling interests. Prior to March 2021, the Company’s noncontrolling interest was redeemable and classified outside of permanent equity because upon certain contingent events not being solely within the Company’s control it may be required to purchase the Company’s RNCI. In March 2021, upon execution of the Reorganization agreements, the Company’s noncontrolling interests became mandatorily redeemable with embedded derivatives and were therefore reclassified from outside of permanent equity to a current liability until settlement at which time the RNCI was no longer subject to allocation of losses or other comprehensive loss.
Reclassification	Reclassification To conform with current year presentation of the Company’s impairment of intangible assets, prior period amounts have been reclassified in the consolidated statements of operations and comprehensive loss.
Recent Accounting Pronouncements	Recent Accounting Pronouncements From time to time, new accounting pronouncements are issued by the Financial Accounting Standards Board or other standards setting bodies that are adopted as of the specified effective date. The Company believes the impact of recently issued standards and any issued but not yet effective standards will not have a material impact on its consolidated financial statements upon adoption.

Summary of Significant Accoun_3

Summary of Significant Accounting Policies (Tables)	12 Months Ended
	Dec. 31, 2022
Cash, Cash Equivalents, Restricted Cash, and Restricted Cash Equivalents [Abstract]
Schedule of Cash, Cash Equivalents and Restricted Cash	The following table provides a reconciliation of cash, cash equivalents and restricted cash, reported within the consolidated statements of cash flows for the years ended December 31, (in thousands): 2022 2021 Cash and cash equivalents $ 55,610 $ 170,064 Restricted cash 831 842 Total cash, cash equivalents, and restricted cash presented in the $ 56,441 $ 170,906
Schedule of Depreciation of Property, Plant and Equipment	Depreciation is calculated over their estimated useful lives as follows: Laboratory equipment 5 years Computer, software and office equipment 3 - 8 years Furniture and fixtures 5 years

Balance Sheets Details (Tables)

Balance Sheets Details (Tables)	12 Months Ended
	Dec. 31, 2022
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Schedule of Prepaid expenses and other current assets	Prepaid expenses and other current assets consist of the following as of December 31, (in thousands): 2022 2021 Tax receivable $ 1,506 $ 104 Prepaid R&D costs 1,476 2,467 Prepaid insurance and service contracts 1,424 1,860 Interest receivable - marketable debt securities 168 — Other 319 230 Total $ 4,893 $ 4,661
Schedule of property and equipment	Property and equipment, net, consist of the following as of December 31, (in thousands): 2022 2021 Laboratory equipment $ 7,559 $ 6,851 Computers, software and office equipment 512 489 Leasehold improvements 467 384 Office furniture and fixtures 123 126 8,661 7,850 Accumulated depreciation and amortization ( 5,617 ) ( 4,866 ) Total $ 3,044 $ 2,984
Schedule of Accrued Liabilities	Accrued liabilities consist of the following as of December 31, (in thousands): 2022 2021 Accrued R&D costs (1) $ 4,069 $ 9,043 Accrued compensation 3,494 3,664 Accrued audit, tax and filing fees 1,703 556 Accrued directors and officers insurance premium (2) 926 — Accrued other 1,122 862 Total $ 11,314 $ 14,125 __________ (1) Includes $ 99 and $ 250 of accrued R&D costs due to related parties as of December 31, 2022 and 2021, respectively. (2) Represents the remaining balance due under the Company’s insurance premium financing agreement, which is payable in equal monthly installments through May 2023 and bears interest at approximately 3.4 % per annum.

Intangible Assets, Net (Tables)

Intangible Assets, Net (Tables)	12 Months Ended
	Dec. 31, 2022
Goodwill and Intangible Assets Disclosure [Abstract]
Schedule of Intangible Assets	Intangible assets, net, consist of the following as of and for the year ended December 31, 2022 (in thousands, except years): Weighted- Gross Impairment (1) Accumulated Intangible Acquired technologies 8.8 $ 24,330 $ ( 9,660 ) $ ( 10,360 ) $ 4,310 IPR&D 20,940 — — 20,940 Total $ 45,270 $ ( 9,660 ) $ ( 10,360 ) $ 25,250 __________ (1) Includes the impairment of BMS Relaxin and BMS FGF-21 intangible assets, as more fully described within the Intangible Assets, Net subsection of Note 2—Summary of Significant Accounting Policies . These intangible asset impairments are presented in the consolidated statements of operations and comprehensive loss as impairment of intangible assets within operating activities. Intangible assets, net, consist of the following as of and for the year ended December 31, 2021 (in thousands, except years): Weighted- Gross Additions Impairment (1) Accumulated Intangible Acquired technologies 9.7 $ 23,870 $ 1,250 $ ( 513 ) $ ( 9,585 ) $ 15,022 IPR&D 20,940 — — — 20,940 Total $ 44,810 $ 1,250 $ ( 513 ) $ ( 9,585 ) $ 35,962 __________ (1) Represents the impairment of an acquired technology intangible asset, as more fully described within the Intangible Assets, Net subsection of Note 2—Summary of Significant Accounting Policies . These intangible asset impairments are presented in the consolidated statements of operations and comprehensive loss as impairment of intangible assets within operating activities.
Schedule of Finite-Lived Intangible Assets, Future Amortization Expense	Future amortization expense is as follows as of December 31, 2022 (in thousands): Year ending December 31, 2023 $ 629 2024 630 2025 629 2026 364 2027 356 Thereafter 1,702 Total $ 4,310

Marketable Debt Securities, A_2

Marketable Debt Securities, Available-for-Sale (Tables)	12 Months Ended
	Dec. 31, 2022
Investments, Debt and Equity Securities [Abstract]
Schedule of Available-for-Sale Debt Securities Reconciliation	The following table summarizes the Company’s MDS as of December 31, 2022 (in thousands): Weighted-Average Amortized Unrealized Unrealized Fair Classified as current assets: Commercial paper 1 or less $ 15,803 $ 1 $ ( 23 ) $ 15,781 Certificates of deposit 1 or less 7,500 2 ( 25 ) 7,477 U.S. government securities 1 or less 5,001 — ( 30 ) 4,971 Corporate bonds 1 or less 646 — ( 2 ) 644 Total Marketable debt securities, 1 or less $ 28,950 $ 3 $ ( 80 ) $ 28,873 Classified as non-current assets: U.S. government securities 1.4 $ 6,979 $ — $ ( 184 ) $ 6,795 Corporate bonds 1.5 6,824 — ( 192 ) 6,632 Asset backed securities 1.8 2,999 — ( 45 ) 2,954 Non-U.S. government securities 1.5 423 — ( 11 ) 412 Total Marketable debt securities, 1.5 $ 17,225 $ — $ ( 432 ) $ 16,793 Total 0.7 $ 46,175 $ 3 $ ( 512 ) $ 45,666
Schedule of Accumulated Unrealized Losses on Debt Securities Classified as Available-for sale	Accumulated unrealized losses on MDS that have been in a continuous loss position for less than 12 months and for more than 12 months as of December 31, 2022, were as follows (in thousands): Less than 12 months More than 12 months Estimated Gross Estimated Gross Commercial paper $ 12,803 $ ( 22 ) $ — $ — U.S. government securities 11,765 ( 216 ) — — Corporate bonds 7,276 ( 193 ) — — Certificates of deposit 2,975 ( 25 ) — — Asset backed securities 2,954 ( 45 ) — — Non-U.S. government securities 412 ( 11 ) — — Total $ 38,185 $ ( 512 ) $ — $ —

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	12 Months Ended
	Dec. 31, 2022
Fair Value Disclosures [Abstract]
Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis	The following table presents the Company’s financial assets measured at fair value on a recurring basis as of December 31, 2022 (in thousands): Total Level 1 Level 2 Level 3 Cash equivalents: Certificates of deposit $ 24,000 $ — $ 24,000 $ — Commercial paper 15,352 — 15,352 — Money market funds 12,743 12,743 — — Total cash equivalents $ 52,095 $ 12,743 $ 39,352 $ — Marketable debt securities, available-for-sale: Commercial paper $ 15,781 $ — $ 15,781 $ — Certificates of deposit 7,477 — 7,477 — U.S. government securities 4,971 — 4,971 — Corporate bonds 644 — 644 — Total Marketable debt securities, available-for-sale $ 28,873 $ — $ 28,873 $ — Marketable debt securities, available-for-sale, net of U.S. government securities $ 6,795 $ — $ 6,795 $ — Corporate bonds 6,632 — 6,632 — Asset backed securities 2,954 — 2,954 — Non-U.S. government securities 412 — 412 — Total Marketable debt securities, available-for-sale, $ 16,793 $ — $ 16,793 $ —

Leases (Tables)

Leases (Tables)	12 Months Ended
	Dec. 31, 2022
Lessee Disclosure [Abstract]
Summary of Components of Operating Lease Expense	The components of lease expense are as follows for the years ended December 31, (in thousands): 2022 2021 Operating lease expenses R&D: Operating lease costs $ 2,217 $ 1,203 Variable lease costs (1) 1,090 1,190 Operating lease expenses G&A: Operating lease costs 509 232 Variable lease costs (1) 236 231 Total operating leases expense $ 4,052 $ 2,856 ____________ (1) Includes short-term lease costs which are immaterial.
Summary of Supplemental balance sheets information related to operating leases	Supplemental balance sheet information related to operating leases is as follows as of December 31, (in thousands): 2022 2021 ROU assets, net $ 10,968 $ 12,737 Operating lease liabilities, current $ 1,734 $ 915 Operating lease liabilities, net of current $ 10,245 $ 12,212
Summary of Supplemental cash flow information related to leases	Supplemental cash flow information related to leases is as follows for the years ended December 31, (in thousands): 2022 2021 Cash paid for amounts included in the measurement of Operating cash flows used for operating leases $ 1,874 $ 1,742 Weighted-average remaining lease term in years 4.9 5.9 Weighted-average discount rate 7.63 % 7.63 %
Summary of Future Lease Liabilities	Future lease liabilities are as follows a s of December 31, 2022 (in thousands): Year ending December 31, 2023 $ 2,814 2024 2,896 2025 2,982 2026 3,071 2027 2,892 Thereafter — 14,655 Less interest expense ( 2,676 ) Total $ 11,979

Revenues (Tables)

Revenues (Tables)	12 Months Ended
	Dec. 31, 2022
Revenue from Contract with Customer [Abstract]
Disaggregation of Revenue	Revenue recognized was earned under the Company’s R&D Agreements and is summarized below based on the nature of payment type for the years ended December 31, (in thousands): Timing of Transfer of Goods or Services 2022 2021 Over time: License fees (1) $ 3,442 $ 3,533 R&D services 2,140 2,072 Reimbursements 820 1,850 Point in time: Milestones 1,000 — Total revenues $ 7,402 $ 7,455 _____________ (1) 2021 license fees include a cumulative catch-up adjustment reducing revenue by approximately $ 1.4 million with an equal increase in total contract liabilities as of December 31, 2021, for changes in total estimated effort to be incurred in the future to satisfy the performance obligation.
Contract with Customer, Contract Asset, Contract Liability, and Receivable	Contract balances are as follows as of December 31, (in thousands): 2022 2021 Receivables, included in accounts receivable, net $ 376 $ 1,239 Contract assets, included in prepaid expenses and other current assets $ — $ 149 Contract liabilities, included in deferred revenue, current and $ 1,749 $ 5,648
Disclosure of Change in Revenue From Contract With Customers	A reconciliation of the beginning and ending amount of contract liabilities, which are primarily related to the combined performance obligation for the transfer of Company’s license and R&D services and conducting R&D activities, which are a separate performance obligation in the Company’s contracts pursuant to research plans under the agreements, was as follows for the years ended December 31, (in thousands): 2022 2021 Beginning balance $ 5,648 $ 9,731 Recognized as revenue: License fees ( 3,442 ) ( 3,548 ) Reimbursements ( 457 ) ( 535 ) Ending balance $ 1,749 $ 5,648

Share-Based Compensation (Table

Share-Based Compensation (Tables)	12 Months Ended
	Dec. 31, 2022
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Summary of Share-based Compensation Expense	Share-based compensation expense was as follows for the years ended December 31, (in thousands): 2022 2021 Research and development $ 3,650 $ 9,001 General and administrative 2,603 2,855 Total share-based compensation expense $ 6,253 $ 11,856
Summary of Options Granted by the Company's Board of Directors	The following tables summarizes option activity for the periods presented: Total Weighted- Aggregate Weighted-Average Outstanding as of December 31, 2021 34,200,976 $ 1.43 $ 912 8.1 Granted 17,058,623 $ 0.45 Canceled ( 12,143,425 ) $ 1.08 Outstanding as of December 31, 2022 39,116,174 $ 1.11 $ 1,088 5.4 Vested and exercisable as of 22,083,111 $ 1.34 $ — 4.6
Employee Stock Option | Employee Share Purchase Plan [Member]
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Summary Of Share Based Payment Award Stock Options Valuation Assumptions	The weighted-average fair value of options and ESPP (as defined below) awards issued was estimated at the date of grant using the BSM with the following weighted-average assumptions for the years ended December 31: Options ESPP 2022 2021 2022 2021 Expected term (in years) 6.0 6.0 1.2 1.3 Risk-free interest rate 2.9 % 1.0 % 2.8 % 0.2 % Expected volatility 82.0 % 80.5 % 79.2 % 74.6 % Dividend yield — — — — Weighted-average grant date fair value $ 0.31 $ 1.20 $ 0.22 $ 0.78

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2022
Income Tax Disclosure [Abstract]
Schedule Of Loss Before Income Tax	Loss before income taxes was as follows for the years ended December 31, (in thousands): 2022 2021 U.S. operations $ ( 73,132 ) $ ( 61,541 ) Non-U.S. operations ( 2,927 ) ( 6,746 ) Loss before provision for income taxes $ ( 76,059 ) $ ( 68,287 )
Schedule of Components of Income Tax Expense (Benefit)	The components of the provision for income taxes was as follows for the years ended December 31, (in thousands): 2022 2021 Current: U.S. $ — $ — State and local 1 1 Foreign 1,936 — Total current 1,937 1 Deferred: U.S. — — Total deferred — — Total provision for income taxes $ 1,937 $ 1
Schedule of Effective Income Tax Rate Reconciliation	reconciliation of the Company’s statutory income tax rate to the Company’s effective income tax rate for the years ended December 31, was as follows: 2022 2021 Income tax benefit at Cayman statutory rate 0.00 % 0.00 % U.S. and non-U.S. rate differential 21.57 % 19.49 % State taxes 4.77 % 3.94 % R&D credits 0.73 % 3.00 % Change in valuation allowance ( 27.61 %) ( 25.79 %) Share-based compensation ( 3.62 %) ( 0.66 %) Ambrx Shanghai reorganization 1.77 % 0.00 % Other, net ( 0.16 %) 0.02 % Effective tax rate ( 2.55 %) ( 0.00 %)
Schedule of Deferred Tax Assets and Liabilities	Significant components of the Company’s deferred tax assets as of December 31, are shown below (in thousands): 2022 2021 Deferred tax assets: Net operating loss carryforwards $ 57,647 $ 48,179 R&D credits 16,385 14,317 Capitalized R&D 8,980 — Lease liabilities 3,110 3,662 Share-based compensation 1,219 3,223 Deferred revenues 454 1,575 Intangible assets 337 — Other 945 1,047 Total deferred tax assets 89,077 72,003 Deferred tax liabilities: IPR&D ( 5,436 ) ( 5,841 ) Right-of-use assets ( 2,847 ) ( 3,553 ) Intangible assets — ( 2,445 ) Total deferred tax liabilities ( 8,283 ) ( 11,839 ) Net deferred tax assets 80,794 60,164 Less: valuation allowance ( 81,674 ) ( 61,044 ) $ ( 880 ) $ ( 880 )
Schedule of Unrecognized Tax Benefits	A reconciliation of the beginning and ending amount of unrecognized tax benefits was as follows (in thousands): December 31, 2022 2021 Beginning balance $ 2,767 $ 2,282 Additions based on tax positions related to the current year 1,958 485 Ending balance $ 4,725 $ 2,767

Related Party Transactions (Tab

Related Party Transactions (Tables)	12 Months Ended
	Dec. 31, 2022
Related Party Transactions [Abstract]
Summary of activities with affiliates of the non controlling shareholders	The following tables present the Company’s activities with affiliates of the noncontrolling shareholders (in thousands): December 31, 2022 2021 Balances: Prepaid R&D expenses $ 14 $ 55 Accounts payable $ 352 $ 167 Accrued liabilities $ 99 $ 250 Years Ended December 31, 2022 2021 Year-to-date activity: Amounts paid $ 776 $ 515 R&D expense recognized $ 146 $ 520

Description of Business and B_2

Description of Business and Basis of Presentation - Additional Information (Detail) - USD ($) $ / shares in Units, $ in Thousands		1 Months Ended		3 Months Ended	12 Months Ended
	Jun. 17, 2021	Jul. 31, 2021	Apr. 30, 2021	Mar. 31, 2022	Dec. 31, 2022	Dec. 31, 2021	Mar. 31, 2021
Organization Consolidation And Presentation Of Financial Statements [Line Items]
Net proceeds from the issuance of common stock					$ 138	$ 148,732
Retained earnings accumulated deficit					(291,628)	(213,632)
Non-current marketable debt securities					16,793	0
Cash and cash equivalents					55,610	170,064
Redeemable non-controlling interest equity redemption value							$ 43,400
Gain (Loss) on Extinguishment of Debt			$ 300
Noncontrolling Interest, Decrease from Redemptions or Purchase of Interests			15,700
Fair Value, Option, Changes in Fair Value, Gain (Loss)					0	(3,903)
Payments to Noncontrolling Interests			$ 21,000		0	$ 20,966
Shangai Ambrx Biopharma Co Ltd [Member]
Organization Consolidation And Presentation Of Financial Statements [Line Items]
Noncontrolling Interest, Ownership Percentage by Noncontrolling Owners			11%
Liquidity and Capital Resources [Member]
Organization Consolidation And Presentation Of Financial Statements [Line Items]
Retained earnings accumulated deficit					291,600
Cash and cash equivalents and marketable debt securities					101,300
Non-current marketable debt securities					$ 16,800
ADR [Member]
Organization Consolidation And Presentation Of Financial Statements [Line Items]
Stock shares issued during the period shares	7,000,000
Sale of stock issue price per share	$ 18
IPO [Member]
Organization Consolidation And Presentation Of Financial Statements [Line Items]
Net proceeds from the issuance of common stock	$ 113,200
Stock issuance costs incurred underwriting discounts and commissions	8,800
Stock Issuance Costs Incurred Professional Fees	$ 4,000
Conversion of temporary equity into permanent equity shares	193,511,558
Over-Allotment Option [Member]
Organization Consolidation And Presentation Of Financial Statements [Line Items]
Stock shares issued during the period shares		892,831
Net proceeds from the issuance of common stock		$ 14,900
Sale of stock issue price per share		$ 18
Additional Paid-in Capital [Member]
Organization Consolidation And Presentation Of Financial Statements [Line Items]
Derivative Assets (Liabilities), at Fair Value, Net			$ 26,300
Shangai Ambrx Biopharma Company Limited [Member]
Organization Consolidation And Presentation Of Financial Statements [Line Items]
Equity method investment ownership percentage					100%
Note payment			$ 190,000	$ 24,000
Stock shares issued during the period shares			2,004,879
Net proceeds from the issuance of common stock			$ 2,100
Loan Settlement and Capital Reduction				$ 166,000	$ 166,000
Fees and interest					1,000
Redeemable non-controlling interest equity redemption value					$ 36,000		$ 36,700
Payments to Noncontrolling Interests			$ 21,000
Biolaxy Pharmaceutical Hongkong Limited [Member]
Organization Consolidation And Presentation Of Financial Statements [Line Items]
Equity method investment ownership percentage					100%
Ambrx US [Member]
Organization Consolidation And Presentation Of Financial Statements [Line Items]
Equity method investment ownership percentage					100%
Ambrx Austrailia Pty Limited [Member]
Organization Consolidation And Presentation Of Financial Statements [Line Items]
Equity method investment ownership percentage					100%

Summary of Significant Accoun_4

Summary of Significant Accounting Policies - Additional Information (Detail) - USD ($) $ in Thousands		3 Months Ended	12 Months Ended
	Feb. 03, 2022	Jun. 30, 2022	Dec. 31, 2022	Dec. 31, 2021
Marketable debt securities, available-for-sale current classification description			maturities of greater than three months and less than 12 months
Marketable debt securities, available-for-sale noncurrent classification description			maturities greater than 12 months
Impairment of intangible assets			$ 9,660	$ 513
Increase Decrease In Revenue Due To Cumulative Catch Up Adjustment				1,400
BMS Relax in Agreement [Member]
Impairment of intangible assets	$ 2,500
BMS FGF-21 Agreement [Member]
Impairment of intangible assets		$ 7,200
Technology-Based Intangible Assets [Member]
Impairment of intangible assets			$ 9,660	$ 513
Maximum [Member] | Technology-Based Intangible Assets [Member]
Finite Lived Intangible Asset Remaining Useful Life			12 years	13 years
Minimum [Member] | Technology-Based Intangible Assets [Member]
Finite Lived Intangible Asset Remaining Useful Life			3 years	4 years
Share-based Payment Arrangement, Option [Member]
Antidilutive securities excluded from computation of Earnings per share, Amount			39,116,174	34,200,976
First Customer From Top Three Customer [Member] | Customer Concentration Risk [Member] | Revenue Benchmark [Member]
Concentration risk, percentage			65.90%	56.80%
Second Customer From Top Three Customer [Member] | Customer Concentration Risk [Member] | Revenue Benchmark [Member]
Concentration risk, percentage			25.60%	35.80%
First Customer [Member] | Customer Concentration Risk [Member] | Accounts Receivable [Member]
Concentration risk, percentage			78.40%	74.60%
Second Customer [Member] | Customer Concentration Risk [Member] | Accounts Receivable [Member]
Concentration risk, percentage			11.80%	21.30%

Summary of Significant Accoun_5

Summary of Significant Accounting Policies - Schedule of Cash, Cash Equivalents and Restricted Cash (Detail) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Cash, Cash Equivalents, Restricted Cash, and Restricted Cash Equivalents [Abstract]
Cash and cash equivalents	$ 55,610	$ 170,064
Restricted cash	831	842
Total cash, cash equivalents, and restricted cash presented in the condensed consolidated statements of cash flows	$ 56,441	$ 170,906	$ 91,278

Summary of Significant Accoun_6

Summary of Significant Accounting Policies - Schedule of Depreciation of Property, Plant and Equipment (Detail)	12 Months Ended
	Dec. 31, 2022
Laboratory equipment
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Useful Life	5 years
Computer, software and office equipment | Minimum [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Useful Life	3 years
Computer, software and office equipment | Maximum [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Useful Life	8 years
Furniture and fixtures
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Useful Life	5 years

Balance Sheets Details - Schedu

Balance Sheets Details - Schedule of Prepaid Expenses and Other Current Assets (Detail) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]
Tax receivable	$ 1,506	$ 104
Prepaid R&D costs	1,476	2,467
Prepaid insurance and service contracts	1,424	1,860
Interest receivable - marketable debt securities	168	0
Other	319	230
Total	$ 4,893	$ 4,661

Balance Sheets Details - Sche_2

Balance Sheets Details - Schedule of Property and Equipment, Net (Detail) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	$ 8,661	$ 7,850
Accumulated depreciation and amortization	(5,617)	(4,866)
Total	3,044	2,984
Laboratory equipment [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	7,559	6,851
Computers, software and office equipment [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	512	489
Leasehold improvements [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	467	384
Office furniture and fixtures [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	$ 123	$ 126

Balance Sheets Details - Sche_3

Balance Sheets Details - Schedule of Accrued Liabilities (Detail) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Payables and Accruals [Abstract]
Accrued R&D costs	$ 4,069	$ 9,043
Accrued compensation	3,494	3,664
Accrued audit, tax and filing fees	1,703	556
Accrued directors and officers insurance premium financing obligation	926	0
Accrued other	1,122	862
Total	$ 11,314	$ 14,125

Balance Sheets Details - Sche_4

Balance Sheets Details - Schedule of Accrued Liabilities (Parenthetical) (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Payables and Accruals [Line Items]
Accrued research and development costs related party	$ 99	$ 250
Insurance Premium Financing Agreement [Member]
Payables and Accruals [Line Items]
Debt instrument interest rate during period	3.40%

Balance Sheets Details - Additi

Balance Sheets Details - Additional Information (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Depreciation and amortization expense	$ 0.8	$ 0.6

Intangible Assets, Net - Schedu

Intangible Assets, Net - Schedule of Intangible Assets (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Schedule Of Intangible Assets Net Excluding Goodwill [Line Items]
Gross Carrying Amount	$ 45,270	$ 44,810
Additions		1,250
Impairment of intangible assets	9,660	513
Accumulated Amortization	(10,360)	(9,585)
Intangible Assets, Net	25,250	35,962
IPR&D [Member]
Schedule Of Intangible Assets Net Excluding Goodwill [Line Items]
Gross Carrying Amount	20,940	20,940
Impairment of intangible assets	0	0
Accumulated Amortization	0	0
Intangible Assets, Net	$ 20,940	$ 20,940
Acquired technologies [Member]
Schedule Of Intangible Assets Net Excluding Goodwill [Line Items]
Weighted-Average Remaining Contractual Life (in Years)	8 years 9 months 18 days	9 years 8 months 12 days
Gross Carrying Amount	$ 24,330	$ 23,870
Additions		1,250
Impairment of intangible assets	9,660	513
Accumulated Amortization	(10,360)	(9,585)
Intangible Assets, Net	$ 4,310	$ 15,022

Intangible Assets, Net - Additi

Intangible Assets, Net - Additional Information (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Goodwill and Intangible Assets Disclosure [Abstract]
Amortization expense for intangible assets	$ 1,052	$ 1,604

Intangible Assets, Net - Summar

Intangible Assets, Net - Summary of Future Amortization Expenses (Detail) $ in Thousands	Dec. 31, 2022 USD ($)
Finite-Lived Intangible Assets, Net, Amortization Expense, Fiscal Year Maturity [Abstract]
2023	$ 629
2024	630
2025	629
2026	364
2027	356
Thereafter	1,702
Total	$ 4,310

Marketable Debt Securities, A_3

Marketable Debt Securities, Available-for-Sale - Schedule of Available-for-Sale Debt Securities Reconciliation (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2022 USD ($)
Debt Securities, Available-for-Sale [Line Items]
Weighted-Average Remaining Contractual Life (in years)	8 months 12 days
Amortized Costs	$ 46,175
Gross Unrealized Gains	3
Gross Unrealized Losses	(512)
Fair Value	45,666
Due Greater than 90 Days and Less than One Year [Member]
Debt Securities, Available-for-Sale [Line Items]
Amortized Costs	28,950
Gross Unrealized Gains	3
Gross Unrealized Losses	(80)
Fair Value	$ 28,873
Due Greater than 90 Days and Less than One Year [Member] | Maximum [Member]
Debt Securities, Available-for-Sale [Line Items]
Weighted-Average Remaining Contractual Life (in years)	1 year
Due Greater than 90 Days and Less than One Year [Member] | Certificates of Deposit [Member]
Debt Securities, Available-for-Sale [Line Items]
Amortized Costs	$ 7,500
Gross Unrealized Gains	2
Gross Unrealized Losses	(25)
Fair Value	$ 7,477
Due Greater than 90 Days and Less than One Year [Member] | Certificates of Deposit [Member] | Maximum [Member]
Debt Securities, Available-for-Sale [Line Items]
Weighted-Average Remaining Contractual Life (in years)	1 year
Due Greater than 90 Days and Less than One Year [Member] | Commercial Paper [Member]
Debt Securities, Available-for-Sale [Line Items]
Amortized Costs	$ 15,803
Gross Unrealized Gains	1
Gross Unrealized Losses	(23)
Fair Value	$ 15,781
Due Greater than 90 Days and Less than One Year [Member] | Commercial Paper [Member] | Maximum [Member]
Debt Securities, Available-for-Sale [Line Items]
Weighted-Average Remaining Contractual Life (in years)	1 year
Due Greater than 90 Days and Less than One Year [Member] | Corporate Debt Securities [Member]
Debt Securities, Available-for-Sale [Line Items]
Amortized Costs	$ 646
Gross Unrealized Losses	(2)
Fair Value	$ 644
Due Greater than 90 Days and Less than One Year [Member] | Corporate Debt Securities [Member] | Maximum [Member]
Debt Securities, Available-for-Sale [Line Items]
Weighted-Average Remaining Contractual Life (in years)	1 year
Due Greater than 90 Days and Less than One Year [Member] | US Government Debt Securities [Member]
Debt Securities, Available-for-Sale [Line Items]
Amortized Costs	$ 5,001
Gross Unrealized Losses	(30)
Fair Value	$ 4,971
Due Greater than 90 Days and Less than One Year [Member] | US Government Debt Securities [Member] | Maximum [Member]
Debt Securities, Available-for-Sale [Line Items]
Weighted-Average Remaining Contractual Life (in years)	1 year
Due One to Two Years [Member]
Debt Securities, Available-for-Sale [Line Items]
Weighted-Average Remaining Contractual Life (in years)	1 year 6 months
Amortized Costs	$ 17,225
Gross Unrealized Losses	(432)
Fair Value	$ 16,793
Due One to Two Years [Member] | Corporate Debt Securities [Member]
Debt Securities, Available-for-Sale [Line Items]
Weighted-Average Remaining Contractual Life (in years)	1 year 6 months
Amortized Costs	$ 6,824
Gross Unrealized Losses	(192)
Fair Value	$ 6,632
Due One to Two Years [Member] | US Government Debt Securities [Member]
Debt Securities, Available-for-Sale [Line Items]
Weighted-Average Remaining Contractual Life (in years)	1 year 4 months 24 days
Amortized Costs	$ 6,979
Gross Unrealized Losses	(184)
Fair Value	$ 6,795
Due One to Two Years [Member] | Asset-Backed Securities [Member]
Debt Securities, Available-for-Sale [Line Items]
Weighted-Average Remaining Contractual Life (in years)	1 year 9 months 18 days
Amortized Costs	$ 2,999
Gross Unrealized Losses	(45)
Fair Value	$ 2,954
Due One to Two Years [Member] | Non-U.S. government securities [Member]
Debt Securities, Available-for-Sale [Line Items]
Weighted-Average Remaining Contractual Life (in years)	1 year 6 months
Amortized Costs	$ 423
Gross Unrealized Losses	(11)
Fair Value	$ 412

Marketable Debt Securities, A_4

Marketable Debt Securities, Available-for-Sale - Additional Information (Details) $ in Thousands	Dec. 31, 2022 USD ($) Security	Dec. 31, 2021 USD ($)
Debt Securities, Available-for-Sale [Line Items]
Fair Value	$ 45,666
Interest receivable - marketable debt securities	$ 168	$ 0
Unrealized loss position of securities | Security	22
Prepaid Expenses and Other Current Assets [Member]
Debt Securities, Available-for-Sale [Line Items]
Interest receivable - marketable debt securities	$ 200

Marketable Debt Securities, A_5

Marketable Debt Securities, Available-for-Sale - Schedule Of Accumulated Unrealized Losses On Debt Securities Classified As Available-For Sale (Details) $ in Thousands	Dec. 31, 2022 USD ($)
Debt Securities, Available-for-Sale [Line Items]
Less than 12 Months, Estimated Fair Value	$ 38,185
Less than 12 Months, Gross Unrealized Losses	(512)
More than 12 Months, Estimated Fair Value	0
More than 12 Months, Gross Unrealized Losses	0
Commercial Paper [Member]
Debt Securities, Available-for-Sale [Line Items]
Less than 12 Months, Estimated Fair Value	12,803
Less than 12 Months, Gross Unrealized Losses	(22)
More than 12 Months, Estimated Fair Value	0
More than 12 Months, Gross Unrealized Losses	0
U.S. government securities [Member]
Debt Securities, Available-for-Sale [Line Items]
Less than 12 Months, Estimated Fair Value	11,765
Less than 12 Months, Gross Unrealized Losses	(216)
More than 12 Months, Estimated Fair Value	0
More than 12 Months, Gross Unrealized Losses	0
Corporate bonds [Member]
Debt Securities, Available-for-Sale [Line Items]
Less than 12 Months, Estimated Fair Value	7,276
Less than 12 Months, Gross Unrealized Losses	(193)
More than 12 Months, Estimated Fair Value	0
More than 12 Months, Gross Unrealized Losses	0
Certificates of Deposit [Member]
Debt Securities, Available-for-Sale [Line Items]
Less than 12 Months, Estimated Fair Value	2,975
Less than 12 Months, Gross Unrealized Losses	(25)
More than 12 Months, Estimated Fair Value	0
More than 12 Months, Gross Unrealized Losses	0
Asset-Backed Securities [Member]
Debt Securities, Available-for-Sale [Line Items]
Less than 12 Months, Estimated Fair Value	2,954
Less than 12 Months, Gross Unrealized Losses	(45)
More than 12 Months, Estimated Fair Value	0
More than 12 Months, Gross Unrealized Losses	0
Non-U.S. government securities [Member]
Debt Securities, Available-for-Sale [Line Items]
Less than 12 Months, Estimated Fair Value	412
Less than 12 Months, Gross Unrealized Losses	(11)
More than 12 Months, Estimated Fair Value	0
More than 12 Months, Gross Unrealized Losses	$ 0

Fair Value Measurements - Addit

Fair Value Measurements - Additional Information (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Fair Value, Recurring [Member]
Cash and cash equivalents, fair value disclosure	$ 52,095,000
Liabilities, fair value disclosure	0
Fair value liability, transfers into level 3	0	$ 0
Fair value liability, transfers out of level 3	0	0
Fair Value, Inputs, Level 1 [Member] | Fair Value, Recurring [Member]
Cash and cash equivalents, fair value disclosure	$ 12,743,000
Money Market Funds [Member]
Cash and cash equivalents, fair value disclosure		$ 162,600,000

Fair Value Measurements - Sched

Fair Value Measurements - Schedule Of Fair Value Assets And Liabilities Measured On Recurring Basis (Detail) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt Securities, Available-for-Sale, Current	$ 28,873	$ 0
Debt Securities, Available-for-Sale, Noncurrent	16,793	$ 0
Fair Value, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and Cash Equivalents, Fair Value Disclosure	52,095
Debt Securities, Available-for-Sale, Current	28,873
Debt Securities, Available-for-Sale, Noncurrent	16,793
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and Cash Equivalents, Fair Value Disclosure	12,743
Debt Securities, Available-for-Sale, Current	0
Debt Securities, Available-for-Sale, Noncurrent	0
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and Cash Equivalents, Fair Value Disclosure	39,352
Debt Securities, Available-for-Sale, Current	28,873
Debt Securities, Available-for-Sale, Noncurrent	16,793
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and Cash Equivalents, Fair Value Disclosure	0
Debt Securities, Available-for-Sale, Current	0
Debt Securities, Available-for-Sale, Noncurrent	0
Fair Value, Recurring [Member] | Commercial Paper [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and Cash Equivalents, Fair Value Disclosure	15,352
Debt Securities, Available-for-Sale, Current	15,781
Fair Value, Recurring [Member] | Commercial Paper [Member] | Fair Value, Inputs, Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and Cash Equivalents, Fair Value Disclosure	0
Debt Securities, Available-for-Sale, Current	0
Fair Value, Recurring [Member] | Commercial Paper [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and Cash Equivalents, Fair Value Disclosure	15,352
Debt Securities, Available-for-Sale, Current	15,781
Fair Value, Recurring [Member] | Commercial Paper [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and Cash Equivalents, Fair Value Disclosure	0
Debt Securities, Available-for-Sale, Current	0
Fair Value, Recurring [Member] | Money Market Funds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and Cash Equivalents, Fair Value Disclosure	12,743
Fair Value, Recurring [Member] | Money Market Funds [Member] | Fair Value, Inputs, Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and Cash Equivalents, Fair Value Disclosure	12,743
Fair Value, Recurring [Member] | Money Market Funds [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and Cash Equivalents, Fair Value Disclosure
Fair Value, Recurring [Member] | Money Market Funds [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and Cash Equivalents, Fair Value Disclosure	0
Fair Value, Recurring [Member] | US Government Debt Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt Securities, Available-for-Sale, Current	4,971
Debt Securities, Available-for-Sale, Noncurrent	6,795
Fair Value, Recurring [Member] | US Government Debt Securities [Member] | Fair Value, Inputs, Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt Securities, Available-for-Sale, Current	0
Debt Securities, Available-for-Sale, Noncurrent	0
Fair Value, Recurring [Member] | US Government Debt Securities [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt Securities, Available-for-Sale, Current	4,971
Debt Securities, Available-for-Sale, Noncurrent	6,795
Fair Value, Recurring [Member] | US Government Debt Securities [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt Securities, Available-for-Sale, Current	0
Debt Securities, Available-for-Sale, Noncurrent	0
Fair Value, Recurring [Member] | Certificates of Deposit [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and Cash Equivalents, Fair Value Disclosure	24,000
Debt Securities, Available-for-Sale, Current	7,477
Fair Value, Recurring [Member] | Certificates of Deposit [Member] | Fair Value, Inputs, Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and Cash Equivalents, Fair Value Disclosure	0
Debt Securities, Available-for-Sale, Current	0
Fair Value, Recurring [Member] | Certificates of Deposit [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and Cash Equivalents, Fair Value Disclosure	24,000
Debt Securities, Available-for-Sale, Current	7,477
Fair Value, Recurring [Member] | Certificates of Deposit [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and Cash Equivalents, Fair Value Disclosure	0
Debt Securities, Available-for-Sale, Current	0
Fair Value, Recurring [Member] | Non US Government Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt Securities, Available-for-Sale, Noncurrent	412
Fair Value, Recurring [Member] | Non US Government Securities [Member] | Fair Value, Inputs, Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt Securities, Available-for-Sale, Noncurrent	0
Fair Value, Recurring [Member] | Non US Government Securities [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt Securities, Available-for-Sale, Noncurrent	412
Fair Value, Recurring [Member] | Non US Government Securities [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt Securities, Available-for-Sale, Noncurrent	0
Fair Value, Recurring [Member] | Asset-Backed Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt Securities, Available-for-Sale, Noncurrent	2,954
Fair Value, Recurring [Member] | Asset-Backed Securities [Member] | Fair Value, Inputs, Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt Securities, Available-for-Sale, Noncurrent	0
Fair Value, Recurring [Member] | Asset-Backed Securities [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt Securities, Available-for-Sale, Noncurrent	2,954
Fair Value, Recurring [Member] | Asset-Backed Securities [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt Securities, Available-for-Sale, Noncurrent	0
Fair Value, Recurring [Member] | Corporate Debt Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt Securities, Available-for-Sale, Current	644
Debt Securities, Available-for-Sale, Noncurrent	6,632
Fair Value, Recurring [Member] | Corporate Debt Securities [Member] | Fair Value, Inputs, Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt Securities, Available-for-Sale, Current	0
Debt Securities, Available-for-Sale, Noncurrent	0
Fair Value, Recurring [Member] | Corporate Debt Securities [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt Securities, Available-for-Sale, Current	644
Debt Securities, Available-for-Sale, Noncurrent	6,632
Fair Value, Recurring [Member] | Corporate Debt Securities [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt Securities, Available-for-Sale, Current	0
Debt Securities, Available-for-Sale, Noncurrent	$ 0

Commitments and Contingencies -

Commitments and Contingencies - Additional Information (Detail) SFr in Millions, $ in Millions			12 Months Ended
	Dec. 11, 2019 CHF (SFr)	Dec. 11, 2019 USD ($)	Dec. 31, 2022 USD ($)	Dec. 31, 2021 USD ($)
Payment of license fees			$ 0.1	$ 1.7
Lonza Sales AG [Member] | Intellectual Property Licenses [Member]
License fee paid amount | SFr	SFr 2
Lonza Sales AG [Member] | Intellectual Property Licenses [Member] | Maximum [Member]
License fee paid amount		$ 2.1

Leases - Summary of Components

Leases - Summary of Components of Operating Lease Expense (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Lessee, Lease, Description [Line Items]
Total operating leases expense	$ 4,052	$ 2,856
Operating lease expenses R&D [Member]
Lessee, Lease, Description [Line Items]
Operating lease costs	2,217	1,203
Variable lease costs	1,090	1,190
Operating lease expenses G&A [Member]
Lessee, Lease, Description [Line Items]
Operating lease costs	509	232
Variable lease costs	$ 236	$ 231

Leases - Summary of Supplementa

Leases - Summary of Supplemental Balance sheets Information Related to Operating Leases (Detail) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Lessee Disclosure [Abstract]
ROU assets, net	$ 10,968	$ 12,737
Operating lease liabilities, current	1,734	915
Operating lease liabilities, net of current	$ 10,245	$ 12,212

Leases - Summary of Supplemen_2

Leases - Summary of Supplemental cash flow information related to leases (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Cash paid for amounts included in the measurement of lease liabilities:
Operating cash flows used for operating leases	$ 1,874	$ 1,742
Weighted-average remaining lease term in years	4 years 10 months 24 days	5 years 10 months 24 days
Weighted-average discount rate	7.63%	7.63%

Leases - Summary of Future Leas

Leases - Summary of Future Lease Liabilities (Detail) $ in Thousands	Dec. 31, 2022 USD ($)
Lessee Disclosure [Abstract]
2023	$ 2,814
2024	2,896
2025	2,982
2026	3,071
2027	2,892
Total	14,655
Less interest expense	(2,676)
Present value of future lease payments	$ 11,979

Leases - Additional Information

Leases - Additional Information (Detail) $ in Thousands	12 Months Ended		72 Months Ended
	Dec. 31, 2022 USD ($)	Dec. 31, 2021 USD ($)	Nov. 30, 2027	Mar. 31, 2005 ft²
Lessee, Lease, Description [Line Items]
Payments for rent	$ 100
Percentage increase decrease in operating lease rent	3%
Area of land | ft²				36,000
Operating lease option to extend			five years
Right of use assets and operating lease liability change from remeasurement		$ 0
Right of use assets and operating lease liability remeasurement gain loss		0
Right of use assets remeasurement impairment charges		0
Increase decrease in right of use assets and operating lease liability		$ 11,500
Other Noncurrent Assets [Member]
Lessee, Lease, Description [Line Items]
Security deposits	$ 300
Maximum [Member]
Lessee, Lease, Description [Line Items]
Operating lease remaining lease term	5 years
Minimum [Member]
Lessee, Lease, Description [Line Items]
Operating lease remaining lease term	2 years

Ordinary Shares and Convertib_2

Ordinary Shares and Convertible Preferred Shares - Additional Information (Detail)			1 Months Ended	3 Months Ended	12 Months Ended
	Jul. 29, 2022 USD ($)	Jun. 17, 2021 USD ($) shares	Jul. 31, 2021 shares	Mar. 31, 2023 USD ($) $ / shares shares	Dec. 31, 2022 USD ($) shares	Dec. 31, 2021 USD ($) shares	Feb. 28, 2023 shares
Convertible Preferred Ordinary Shares And Ordinary Shares [Line Items]
Common stock shares authorized					500,000,000	500,000,000
Net proceeds from the issuance of common stock | $					$ 138,000	$ 148,732,000
Subsequent Event [Member]
Convertible Preferred Ordinary Shares And Ordinary Shares [Line Items]
Common stock shares authorized							600,000,000
Restated Memorandum And Articles Of Association [Member]
Convertible Preferred Ordinary Shares And Ordinary Shares [Line Items]
Common stock shares authorized					500,000,000
Undesignated shares authorized					100,000,000
Common Stock [Member]
Convertible Preferred Ordinary Shares And Ordinary Shares [Line Items]
Stock shares issued during the period shares		49,000,000			334,684	21,189,173
Entity listing depository receipt ratio					7
Issuance of ordinary shares			6,249,817
IPO [Member]
Convertible Preferred Ordinary Shares And Ordinary Shares [Line Items]
Net proceeds from the issuance of common stock | $		$ 113,200,000
IPO [Member] | Common Stock [Member]
Convertible Preferred Ordinary Shares And Ordinary Shares [Line Items]
Stock shares issued during the period shares						49,000,000
ATM Offering Program [Member] | Maximum [Member]
Convertible Preferred Ordinary Shares And Ordinary Shares [Line Items]
Aggregate offering price | $	$ 80,000,000
ATM Offering Program [Member] | Subsequent Event [Member]
Convertible Preferred Ordinary Shares And Ordinary Shares [Line Items]
Commission on sale of common stock | $				$ 2,000,000
Net proceeds from the issuance of common stock | $				78,000,000
Gross proceeds from issuance of common stock including sales commissions | $				$ 80,000,000
ADR [Member]
Convertible Preferred Ordinary Shares And Ordinary Shares [Line Items]
Stock shares issued during the period shares		7,000,000
Issuance of ordinary shares			892,831
ADR [Member] | ATM Offering Program [Member] | Subsequent Event [Member]
Convertible Preferred Ordinary Shares And Ordinary Shares [Line Items]
Average stock price per share | $ / shares				$ 4.83
Shares issued and sold during the period shares				16,575,826
ADR [Member] | ATM Offering Program [Member] | Common Stock [Member]
Convertible Preferred Ordinary Shares And Ordinary Shares [Line Items]
Entity listing depository receipt ratio	7

Revenues - Schedule of Revenue

Revenues - Schedule of Revenue Recognized (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Disaggregation of Revenue [Line Items]
Revenue from contract with customer, excluding assessed tax	$ 7,402	$ 7,455
License Fees [Member] | Over Time [Member]
Disaggregation of Revenue [Line Items]
Revenue from contract with customer, excluding assessed tax	3,442	3,533
Reimbursements [Member] | Over Time [Member]
Disaggregation of Revenue [Line Items]
Revenue from contract with customer, excluding assessed tax	820	1,850
Milestones [Member] | Point in Time [Member]
Disaggregation of Revenue [Line Items]
Revenue from contract with customer, excluding assessed tax	1,000
Research And Development Services [Member] | Over Time [Member]
Disaggregation of Revenue [Line Items]
Revenue from contract with customer, excluding assessed tax	$ 2,140	$ 2,072

Revenues - Schedule of Revenu_2

Revenues - Schedule of Revenue Recognized (Detail) (Parenthtical) $ in Millions	12 Months Ended
	Dec. 31, 2021 USD ($)
Revenue from Contract with Customer [Abstract]
Increase Decrease In Revenue Due To cumulative catch up Adjustment	$ 1.4

Revenues - Additional Informati

Revenues - Additional Information (Detail) $ in Thousands	1 Months Ended				3 Months Ended	12 Months Ended
	Mar. 30, 2023	Jan. 31, 2020 USD ($)	Oct. 31, 2019 USD ($) FullTimeEquivalentServices	Mar. 31, 2019 USD ($) FullTimeEquivalentServices	Dec. 31, 2022 USD ($)	Dec. 31, 2022 USD ($)	Dec. 31, 2021 USD ($)	Dec. 31, 2020 Patients
Disaggregation of Revenue [Line Items]
Performance obligations remaining amount					$ 100	$ 100	$ 1,200
Revenue from performance obligations of the previous period recognized							0
Deferred Revenue					1,700	1,700	5,700
Milestone revenue upon closing of first patient with ARX305						$ 7,402	$ 7,455
Bigene Limited [Member]
Disaggregation of Revenue [Line Items]
Upfront payment received towards license fees				$ 10,000
Bigene Limited [Member] | Collaboration and Exclusive License Agreement [Member]
Disaggregation of Revenue [Line Items]
Notice period to be given by the counterparty for the termination of the license agreement				3 months
Bigene Limited [Member] | Collaboration and Exclusive License Agreement [Member] | Subsequent Event [Member]
Disaggregation of Revenue [Line Items]
Initial research term extension period	2 years
Novocodex [Member] | Development and Commercialization Agreement [Member]
Disaggregation of Revenue [Line Items]
Upfront payment received towards license fees			$ 2,000
Notice period to be given by the counterparty for the termination of the license agreement			6 months
Novocodex [Member] | Development and Commercialization Agreement [Member] | Point in Time [Member]
Disaggregation of Revenue [Line Items]
Milestone revenue upon closing of first patient with ARX305					$ 1,000
Sino Biopharmaceutical Limited [Member] | Development and Commercialization Agreement [Member]
Disaggregation of Revenue [Line Items]
Upfront payment received towards license fees		$ 10,000
Notice period to be given by the counterparty for the termination of the license agreement						6 months
Sino Biopharmaceutical Limited [Member] | Development and Commercialization Agreement [Member] | Phase One Clinical Trial for Products ARX Eight Twenty Two and Arx One Hundred and Two [Member]
Disaggregation of Revenue [Line Items]
Total number of patients for which the drug study detail is to be given by the counterparties | Patients								100
Minimum [Member]
Disaggregation of Revenue [Line Items]
Remaining performance obligations remaining satisfaction period					1 year	1 year
Minimum [Member] | Bigene Limited [Member] | Collaboration and Exclusive License Agreement [Member]
Disaggregation of Revenue [Line Items]
Number of full time equivalent services to be performed for receiving research and development related amount | FullTimeEquivalentServices				2
Minimum [Member] | Novocodex [Member] | Development and Commercialization Agreement [Member]
Disaggregation of Revenue [Line Items]
Number of full time equivalent services to be performed for receiving research and development related amount | FullTimeEquivalentServices			1
Maximum [Member]
Disaggregation of Revenue [Line Items]
Remaining performance obligations remaining satisfaction period					4 years	4 years
Maximum [Member] | Bigene Limited [Member] | Collaboration and Exclusive License Agreement [Member]
Disaggregation of Revenue [Line Items]
Number of full time equivalent services to be performed for receiving research and development related amount | FullTimeEquivalentServices				25

Revenues - Schedule of the Cont

Revenues - Schedule of the Contract Balances (Detail) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Revenue from Contract with Customer [Abstract]
Receivables, included in accounts receivable, net	$ 376	$ 1,239
Contract assets, included in prepaid expenses and other current assets	0	149
Contract liabilities included in deferred revenue, current and deferred revenue net of current portion	$ 1,749	$ 5,648

Revenues - Schedule of Summariz

Revenues - Schedule of Summarizes Unrecognized Contract (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Disaggregation of Revenue [Line Items]
Beginning balance	$ 5,648	$ 9,731
Upfront fees:
Ending balance	1,749	5,648
License Fees [Member]
Upfront fees:
Contract with Customer, Liability, Revenue Recognized	(3,442)	(3,548)
Reimbursements [Member]
Upfront fees:
Contract with Customer, Liability, Revenue Recognized	$ (457)	$ (535)

Share-Based Compensation - Summ

Share-Based Compensation - Summary of Share-based Compensation Expense (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Share-Based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Allocated share based compensation expense	$ 6,253	$ 11,856
Research and Development Expense [Member]
Share-Based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Allocated share based compensation expense	3,650	9,001
General and Administrative[Member]
Share-Based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Allocated share based compensation expense	$ 2,603	$ 2,855

Share-Based Compensation - Addi

Share-Based Compensation - Additional Information (Detail)					12 Months Ended
	Jan. 27, 2023 $ / shares shares	Jan. 01, 2023 shares	Jan. 01, 2022 shares	Jun. 17, 2021 USD ($)	Dec. 31, 2022 USD ($) Offering $ / shares shares	Dec. 31, 2021 USD ($) $ / shares shares
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Vested and exercisable share					22,083,111	18,950,899
Weighted-average exercise price of vested and exercisable shares outstanding | $ / shares						$ 1.28
Allocated share based compensation expense | $					$ 6,253,000	$ 11,856,000
Weighted average exercise price, granted | $ / shares					$ 0.45
Net proceeds from the issuance of common stock | $					$ 138,000	148,732,000
Aggregate Intrinsic Value, Outstanding | $					1,088,000	912,000
Share based payment arrangement nonvested award cost not yet recognized period for recognition | $					$ 9,100,000
Share-based payment arrangement, nonvested award, cost not yet recognized, period for recognition					3 years 7 months 6 days
Share-based compensation expense | $					$ 6,253,000	$ 11,856,000
IPO [Member]
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Net proceeds from the issuance of common stock | $				$ 113,200,000
Share-Based Payment Arrangement, Option [Member]
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Weighted average grant date fair value | $ / shares					$ 0.31	$ 1.20
Share-Based Payment Arrangement, Option [Member] | IPO [Member]
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Share based compensation by share based award options vested during the period shares						7,700,000
Allocated share based compensation expense | $						$ 6,400,000
Option Repricing Program [Member] | Subsequent Event [Member]
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Ordinary shares repriced shares outstanding	17,285,155
exercise price | $ / shares	$ 0.28
Weighted average exercise price, granted | $ / shares	$ 0.28
Ordinary shares repriced as a percentage of options outstanding	43%
American Depositary Shares [Member] | Option Repricing Program [Member] | Subsequent Event [Member]
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
exercise price | $ / shares	$ 1.95
Two Thousand and Sixteen Equity Incentive Plan [Member]
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Share-based compensation arrangement by Share-based payment award, purchase price of common stock, percent					100%
Share-based compensation arrangement by Share-based payment award, expiration period					10 years
Share-based compensation arrangement by share-based payment award, award vesting period					4 years
Two Thousand and Twenty One Equity Incentive Plan [Member]
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Common stock, capital shares reserved for future issuance					200,000,000
Increase in the number of shares reserved for future issuance as a percentage of common stock shares outstanding					5%
Share-based compensation arrangement by share-based payment award, number of shares authorized						56,094,909
Issuance of ordinary shares upon exercise of options (in shares)					0	79,212
Share-based payment award, options, exercises in period | $						$ 100,000
Net proceeds from the issuance of common stock | $						$ 100,000
Two Thousand and Twenty One Equity Incentive Plan [Member] | Share-Based Payment Arrangement, Tranche One [Member]
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Share based compensation by share based arrangement remaining vesting period					3 years
Share-Based Compensation Arrangement by Share-Based Payment Award, Award Vesting Rights, Percentage					25%
Two Thousand and Twenty One Employee Share Purchase Plan [Member]
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Share-based compensation arrangement by share-based payment award, percentage of outstanding stock maximum					1%
Share-based compensation arrangement by share-based payment award, number of shares authorized						3,000,000
Employee stock purchase plan maximum contributions per employee percent					15%
Date of expiry of the employee stock purchase plan					Jan. 01, 2031
Period for which the offer is open					2 years
Employee stock purchase plan duration of purchase period					6 months
Employee stock purchase plan number of purchase period | Offering					4
Employee Share Purchase Plan [Member]
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Share-based compensation arrangement by share-based payment award, number of shares authorized			5,701,205
Issuance of ordinary shares for cash (in shares)					334,684	105,329
Net proceeds from the issuance of common stock | $					$ 100,000	$ 100,000
Weighted average grant date fair value | $ / shares					$ 0.22	$ 0.78
Share-based compensation arrangement by share-based payment award, number of additional shares authorized		2,704,552	2,701,205
Share-based compensation expense | $					$ 0
Employee Share Purchase Plan [Member] | Subsequent Event [Member]
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Share-based compensation arrangement by share-based payment award, number of shares authorized		8,405,757
Two Thousand And Twenty One Plan [Member]
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Share-based compensation arrangement by share-based payment award, number of shares authorized			69,600,936
Share-based compensation arrangement by share-based payment award, number of additional shares authorized			13,506,027
Two Thousand And Twenty One Plan [Member] | Subsequent Event [Member]
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Share-based compensation arrangement by share-based payment award, number of shares authorized		83,123,698
Share-based compensation arrangement by share-based payment award, number of additional shares authorized		13,522,762

Share-Based Compensation - Su_2

Share-Based Compensation - Summary of Options Granted by the Company's Board of Directors (Detail) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Beginning balance, Total Options	34,200,976
Total Options, Granted	17,058,623
Total Options, Canceled	(12,143,425)
Ending balance, Total Options	39,116,174	34,200,976
Total Options, Vested and Exercisable	22,083,111	18,950,899
Beginning balance, Weighted Average Exercise Price	$ 1.43
Weighted Average Exercise Price, Granted	0.45
Weighted Average Exercise Price, Canceled	1.08
Ending balance, Weighted Average Exercise Price	1.11	$ 1.43
Weighted Average Exercise Price, Vested and Exercisable	$ 1.34
Aggregate Intrinsic Value, Outstanding	$ 1,088	$ 912
Weighted Average Remaining Contractual Term, Outstanding	5 years 4 months 24 days	8 years 1 month 6 days
Weighted Average Remaining Contractual Life, Vested and Exercisable	4 years 7 months 6 days

Share-Based Compensation - Su_3

Share-Based Compensation - Summary of Share Based Payment Award Stock Options Valuation Assumptions (Detail) - $ / shares	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Employee Share Purchase Plan [Member]
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Expected term (in years)	1 year 2 months 12 days	1 year 3 months 18 days
Risk-free interest rate	2.80%	0.20%
Expected volatility	79.20%	74.60%
Weighted average grant date fair value	$ 0.22	$ 0.78
Employee Stock Option
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Expected term (in years)	6 years	6 years
Risk-free interest rate	2.90%	1%
Expected volatility	82%	80.50%
Weighted average grant date fair value	$ 0.31	$ 1.20

Defined Contribution Plan - Add

Defined Contribution Plan - Additional Information (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Four Zero One K Plan [Member]
Discretionary contribution	$ 0.4	$ 0.3

Income Taxes - Schedule Of Loss

Income Taxes - Schedule Of Loss Before Income Tax (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Loss before provision for income taxes	$ (76,059)	$ (68,287)
U.S. operations
Loss before provision for income taxes	(73,132)	(61,541)
Non-U.S. operations
Loss before provision for income taxes	$ (2,927)	$ (6,746)

Income Taxes - Schedule of Comp

Income Taxes - Schedule of Components of Income Tax Expense (Benefit) (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Current:
State and local	$ 1	$ 1
Foreign	1,936
Total current	1,937	1
Deferred:
Total provision for income taxes	$ 1,937	$ 1

Income Taxes - Schedule of Effe

Income Taxes - Schedule of Effective Income Tax Rate Reconciliation (Detail)	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Income Tax Disclosure [Abstract]
Income tax benefit at Cayman statutory rate	0%	0%
U.S. and non-U.S. rate differential	21.57%	19.49%
State taxes	4.77%	3.94%
R&D credits	0.73%	3%
Change in valuation allowance	(27.61%)	(25.79%)
Share-based compensation	(3.62%)	(0.66%)
Ambrx Shanghai reorganization	1.77%	0%
Other, net	(0.16%)	0.02%
Effective tax rate	(2.55%)	(0.00%)

Income Taxes - Schedule of Defe

Income Taxes - Schedule of Deferred Tax Assets and Liabilities (Detail) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Deferred tax assets:
Net operating loss carryforwards	$ 57,647	$ 48,179
R&D credits	16,385	14,317
Capitalized R&D	8,980
Lease liabilities	3,110	3,662
Share-based compensation	1,219	3,223
Deferred revenues	454	1,575
Intangible assets	337
Other	945	1,047
Total deferred tax assets	89,077	72,003
Deferred tax liabilities:
IPR&D	(5,436)	(5,841)
Right-of-use assets	2,847	3,553
Intangible assets		(2,445)
Total deferred tax liabilities	(8,283)	(11,839)
Net deferred tax assets	80,794	60,164
Less: valuation allowance	(81,674)	(61,044)
Total net deferred tax liabilities	$ (880)	$ (880)

Income Taxes - Schedule of Unre

Income Taxes - Schedule of Unrecognized Tax Benefits (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Income Tax Disclosure [Abstract]
Beginning balance	$ 2,767,000	$ 2,282,000
Additions based on tax positions related to the current year	1,958,000	485,000
Ending balance	$ 4,725,000	$ 2,767,000

Income Taxes - Additional Infor

Income Taxes - Additional Information (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Changes in valuation allowance	$ 20,600,000	$ 17,600,000
R&D activities amortization period	5 years
Foreign R&D activities amortization period	15 years
R&D expenses capitalized	$ 49,500,000
Unrecognized tax benefits that would impact effective tax rate	3,300,000
Uncertain tax positions	4,725,000	$ 2,767,000	$ 2,282,000
Accrued penalties on uncertain tax positions	200,000
Research Tax Credit Carryforward
Tax credit carryforward	$ 12,300,000
Tax credit carryforward, expiration date	2024
Domestic Tax Authority
Operating loss carryforwards	$ 103,500,000
Operating loss carryforwards, expiration date	2025
State and Local Jurisdiction
Operating loss carryforwards	$ 136,200,000
Tax credit carryforward	$ 8,900,000
Operating loss carryforwards, expiration date	2028
Foreign Tax Authority
Operating loss carryforwards	$ 13,700,000
Operating loss carryforwards, expiration date	2023
Not Expirable | Domestic Tax Authority
Operating loss carryforwards	$ 107,100,000
Not Expirable | Foreign Tax Authority
Operating loss carryforwards	$ 1,700,000

Related Party Transactions - Su

Related Party Transactions - Summary of Activities with Affiliates of the Non Controlling Shareholders (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Related Party Transaction [Line Items]
Prepaid R&D expenses	$ 14	$ 55
Accounts payable	352	167
Accrued liabilities	99	250
Amounts paid	776	515
R&D expense recognized	$ 146	$ 520