Ambrx Biopharma (AMAM) 10-Q 11 May 23 2023 Q1 Quarterly report Financial data

Cover Page

Cover Page - shares	3 Months Ended
	Mar. 31, 2023	May 08, 2023
Document Information [Line Items]
Document Type	10-Q
Entity Registrant Name	Ambrx Biopharma Inc.
Amendment Flag	false
Document Period End Date	Mar. 31, 2023
Document Fiscal Year Focus	2023
Document Fiscal Period Focus	Q1
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
Entity Tax Identification Number	00-0000000
Document Quarterly Report	true
Document Transition Report	false
Entity Ex Transition Period	true
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
Entity Shell Company	false
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		386,606,014
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

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Mar. 31, 2023	Dec. 31, 2022
Current assets:
Cash and cash equivalents	$ 149,584	$ 55,610
Restricted cash	665	831
Marketable debt securities, available-for-sale	7,940	28,873
Accounts receivable, net	62	376
Prepaid expenses and other current assets	4,691	4,893
Total current assets	162,942	90,583
Marketable debt securities, available-for-sale, net of current portion	8,798	16,793
Property and equipment, net	2,889	3,044
Right-of-use assets, net	10,511	10,968
Intangible assets, net	25,093	25,250
Other long-term assets	380	339
Total assets	210,613	146,977
Current liabilities:
Accounts payable	7,107	3,205
Accrued liabilities	6,782	11,314
Operating lease liabilities, current portion	1,793	1,734
Deferred revenue, current portion	407	407
Total current liabilities	16,089	16,660
Operating lease liabilities, net of current portion	9,710	10,245
Deferred tax liabilities	880	880
Deferred revenue, net of current portion	1,342	1,342
Total liabilities	28,021	29,127
Commitments and contingencies (Note 7)
Shareholders' Equity (Deficit):
Ordinary Shares, par value $0.0001; 600,000,000 and 500,000,000 shares authorized at March 31, 2023 and December 31, 2022, respectively; 386,486,014 and 270,455,232 shares issued and outstanding at March 31, 2023 and December 31, 2022, respectively	39	27
Additional paid-in capital	490,459	410,753
Accumulated other comprehensive loss	(976)	(1,302)
Accumulated deficit	(306,930)	(291,628)
Total shareholders' equity	182,592	117,850
Total liabilities and shareholders' equity	$ 210,613	$ 146,977

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - $ / shares	Mar. 31, 2023	Dec. 31, 2022
Common Stock, Par or Stated Value Per Share	$ 0.0001	$ 0.0001
Common Stock, Shares Authorized	600,000,000	500,000,000
Common Stock, Shares, Issued	386,486,014	270,455,232
Common Stock, Shares, Outstanding	386,486,014	270,455,232

Consolidated Statements of Oper

Consolidated Statements of Operations and comprehensive Loss - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Revenues	$ 24	$ 1,613
Operating expenses:
Research and development	9,750	14,704
General and administrative	6,306	4,570
Impairment of intangible assets	0	2,465
Total operating expenses	16,056	21,739
Loss from operations	(16,032)	(20,126)
Other income (expense), net:
Investment income, net	551	0
Interest income (expense), net	190	(954)
Other income, net	62	20
Total other income (expense), net	803	(934)
Loss before income taxes	(15,229)	(21,060)
Provision for income taxes	(73)	(1,587)
Net loss	$ (15,302)	$ (22,647)
Net loss per share - basic	$ (0.05)	$ (0.08)
Net loss per share - diluted	$ (0.05)	$ (0.08)
Weighted-average ordinary shares used to compute net loss per share attributable to ordinary shareholders, basic	314,969,897	270,124,173
Weighted-average ordinary shares used to compute net loss per share attributable to ordinary shareholders, diluted	314,969,897	270,124,173
Other comprehensive loss, net of tax:
Net loss	$ (15,302)	$ (22,647)
Changes in comprehensive loss before reclassifications	(26)	0
Amounts reclassified from accumulated other comprehensive loss	352	0
Total other comprehensive income	326	0
Comprehensive loss	$ (14,976)	$ (22,647)

Condensed Consolidated Statemen

Condensed Consolidated Statements of Changes In Shareholders' Equity - USD ($) $ in Thousands	Total	Ordinary Shares [Member]	Additional Paid-In-Capital [Member]	Accumulated Other Comprehensive Loss [Member]	Accumulated Deficit [Member]
Beginning balance at Dec. 31, 2021	$ 189,967	$ 27	$ 404,362	$ (790)	$ (213,632)
Beginning balance (in shares) at Dec. 31, 2021		270,120,548
Share-based compensation	1,650		1,650
Issuance of ordinary shares for cash, net of issuance costs	7		7
Issuance of ordinary shares for cash, net of issuance costs (in shares)		6,398
Net loss	(22,647)				(22,647)
Ending balance at Mar. 31, 2022	168,977	$ 27	406,019	(790)	(236,279)
Ending balance (in shares) at Mar. 31, 2022		270,126,946
Beginning balance at Dec. 31, 2022	117,850	$ 27	410,753	(1,302)	(291,628)
Beginning balance (in shares) at Dec. 31, 2022		270,455,232
Share-based compensation	1,938		1,938
Issuance of ordinary shares for cash, net of issuance costs	77,780	$ 12	77,768
Issuance of ordinary shares for cash, net of issuance costs (in shares)		116,030,782
Change in unrealized loss on marketable debt securities available-for-sale	326			326
Net loss	(15,302)				(15,302)
Ending balance at Mar. 31, 2023	$ 182,592	$ 39	$ 490,459	$ (976)	$ (306,930)
Ending balance (in shares) at Mar. 31, 2023		386,486,014

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Cash flows from operating activities:
Net loss	$ (15,302)	$ (22,647)
Noncash adjustments reconciling net loss to cash flows from operating activities:
Loss on impairment of intangible assets	0	2,465
Share-based compensation expense	1,938	1,650
Noncash lease expense	712	683
Amortization of intangible assets	157	368
Depreciation and amortization	208	190
Accretion/amortization of investment securities, net	(299)	0
Loss on disposal of property and equipment	1	0
Changes in operating assets and liabilities:
Accounts receivable, net	314	(237)
Prepaid and other current assets and other long-term assets	159	(1,358)
Accounts payable	3,886	(920)
Accrued liabilities	(4,010)	(4,368)
Deferred revenue	0	(893)
Operating lease liabilities	(731)	(597)
Net cash used in operating activities	(12,967)	(25,664)
Cash flows from investing activities:
Purchases of marketable debt securities, available-for-sale	(40,645)	0
Sales of marketable debt securities, available-for-sale	50,799	0
Maturities of marketable debt securities, available-for-sale	19,400	0
Purchases of property and equipment	0	(774)
Net cash provided by (used in) investing activities	29,554	(774)
Cash flows from financing activities:
Proceeds from short-term bridge loan	0	166,000
Repayment of short-term bridge loan	0	(166,000)
Payments of directors and officers insurance premium financing agreement	(559)	0
Proceeds from issuance of ordinary shares, net of issuance costs	77,780	7
Payments of costs for the issuance of ordinary shares	0	(13)
Net cash provided by (used in) financing activities	77,221	(6)
Net increase (decrease) in cash, cash equivalents and restricted cash	93,808	(26,444)
Cash, cash equivalents and restricted cash, beginning of period	56,441	170,906
Cash, cash equivalents and restricted cash, end of period	150,249	144,462
Supplemental information:
Cash paid for interest	0	963
Cash paid for income taxes	0	1
Noncash investing and financing activities:
Property and equipment costs in accounts payable and accrued liabilities	$ 545	$ 369

Description of Business and Bas

Description of Business and Basis of Presentation	3 Months Ended
	Mar. 31, 2023
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 condensed consolidated financial statements, the Company owned 100 % of Shanghai Ambrx Biopharma Company Limited (Ambrx Shanghai) 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. Basis of Presentation and Principles of Consolidation The condensed 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 condensed 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. Unaudited Interim Financial Information The interim condensed consolidated financial statements are unaudited. These unaudited interim condensed consolidated financial statements have been prepared in accordance with U.S. GAAP and following the requirements of the United States Securities and Exchange Commission (the SEC) for interim reporting. As permitted under those rules, certain footnotes or other financial information that are normally required by U.S. GAAP can be condensed or omitted. In management’s opinion, the unaudited interim condensed consolidated financial statements have been prepared on the same basis as the audited consolidated financial statements and include all adjustments, which include only normal recurring adjustments, necessary for the fair presentation of the Company’s financial position, its results of operations, equity activities and its cash flows for the periods presented. These statements do not include all disclosures required by U.S. GAAP and should be read in conjunction with the Company’s audited consolidated financial statements and notes for the fiscal year ended December 31, 2022, contained in the Company’s Annual Report on Form 10-K filed by the Company with the SEC on March 30, 2023 (the Annual Report). The results for the three months ended March 31, 2023, are not necessarily indicative of the results expected for the full fiscal year or any other future interim or annual period. 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 $ 306.9 million as of March 31, 2023. As of March 31, 2023, the Company had cash, cash equivalents and marketable debt securities, available-for-sale (MDS) of $ 166.3 million, of which $ 8.8 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 condensed 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 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	3 Months Ended
	Mar. 31, 2023
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	2. Summary of Significant Accounting Policies There have been no material changes to the Company’s significant accounting policies from those described in the notes to the audited consolidated financial statements of the Company as of and for the years ended December 31, 2022 and 2021 contained in the Annual Report. Risks and Uncertainties 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 condensed 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 March 31, 2023. While there was no material impact to the Company’s condensed consolidated financial statements as of and for the three months ended March 31, 2023 , these estimates may change, as new events occur and additional information is obtained, which could materially impact the Company’s condensed consolidated financial statements in future reporting periods. 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 Federal Deposit Insurance Corporation 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 three months ended March 31, 2023, revenues from the Company’s top two customers represented 75.0 % and 25.0 % of total revenues, respectively. During the three months ended March 31, 2022, revenues from the Company’s top three customers represented 75.6 %, 13.8 % and 10.5 % of total revenues, respectively. As of March 31, 2023, billed accounts receivable for two customers represented 73.4 % and 17.9 % of total billed receivables, respectively. As of March 31, 2022, billed accounts receivable for two customers represented 57.8 % and 40.3 % 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 condensed consolidated statements of cash flows (in thousands): Three Months Ended March 31, 2023 2022 Cash and cash equivalents $ 149,584 $ 143,631 Restricted cash 665 831 Total cash, cash equivalents, and restricted cash presented in the $ 150,249 $ 144,462 As of March 31, 2023 and 2022 , 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 March 31, 2023 and December 31, 2022 , the Company has determined an allowance for expected credit losses is not material. 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 2.8 to 11.8 years as of March 31, 2023, and three to 12 years as of December 31, 2022. Amortization expense for the Company’s finite lived intangible assets is charged to research and development expense in the condensed 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. 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. 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. 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. There were no impairment charges recognized during the three months ended March 31, 2023 . 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 46,721,145 and 39,754,803 ordinary shares for the three months ended March 31, 2023 and 2022 , respectively. 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 condensed consolidated financial statements upon adoption.

Marketable Debt Securities, Ava

Marketable Debt Securities, Available-for-Sale	3 Months Ended
	Mar. 31, 2023
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 March 31, 2023 (dollars in thousands): Weighted Amortized Unrealized Unrealized Fair Classified as current assets: U.S. government securities 1 or less $ 6,479 $ 1 $ ( 13 ) $ 6,467 Commercial paper 1 or less 1,473 — — 1,473 Total Marketable debt securities, 1 or less $ 7,952 $ 1 $ ( 13 ) $ 7,940 Classified as non-current assets: U.S. government securities 1.1 $ 6,983 $ — $ ( 140 ) $ 6,843 Corporate bonds 1.2 1,989 — ( 34 ) 1,955 Total Marketable debt securities, 1.2 $ 8,972 $ — $ ( 174 ) $ 8,798 Total 0.7 $ 16,924 $ 1 $ ( 187 ) $ 16,738 The following table summarizes the Company’s MDS as of December 31, 2022 (dollars in thousands): Weighted 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 March 31, 2023 and December 31, 2022, the Company had $ 0.2 million of accrued interest on MDS included in prepaid expenses and other current assets in the condensed consolidated balance sheets. The following tables present gross unrealized losses and fair values for those investments that were in an unrealized loss position as of March 31, 2023 and December 31, 2022, aggregated by investment category for MDS that have been in a continuous loss position for less than 12 months and for more than 12 months (in thousands): Less than 12 months More than 12 months Estimated Gross Estimated Gross March 31, 2023 U.S. government securities $ 9,832 $ ( 153 ) $ — $ — Corporate bonds 1,955 ( 34 ) — — Total $ 11,787 $ ( 187 ) $ — $ — December 31, 2022 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 March 31, 2023, a total of seven 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 recognized in investment income were de minimis and $ 0.4 million, respectively, for the three months ended March 31, 2023. During the three months ended March 31, 2022 , the Company did no t hold MDS.

Balance Sheets Details

Balance Sheets Details	3 Months Ended
	Mar. 31, 2023
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 (in thousands): March 31, December 31, Tax receivable $ 2,062 $ 1,506 Prepaid R&D costs 1,286 1,476 Prepaid insurance and service contracts 913 1,424 Interest receivable - MDS 192 168 Other 238 319 Total $ 4,691 $ 4,893 Property and Equipment, Net Property and equipment, net, consist of the following (in thousands): March 31, December 31, Laboratory equipment $ 7,597 $ 7,559 Computers, software and office equipment 512 512 Leasehold improvements 467 467 Office furniture and fixtures 123 123 8,699 8,661 Accumulated depreciation and amortization ( 5,810 ) ( 5,617 ) Total $ 2,889 $ 3,044 Depreciation and amortization expense for property and equipment is disclosed on the condensed consolidated statements of cash flows. Accrued Liabilities Accrued liabilities consist of the following (in thousands): March 31, December 31, Accrued R&D costs (1) $ 2,065 $ 4,069 Accrued compensation 1,593 3,494 Accrued audit, tax and filing fees 1,917 1,703 Accrued directors and officers insurance premium (2) 372 926 Accrued other 835 1,122 Total $ 6,782 $ 11,314 __________ (1) Includes $ 42 and $ 99 of accrued R&D costs due to related parties as of March 31, 2023 and December 31, 2022 , 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. Accumulated Other Comprehensive Loss The following table provides a reconciliation of the components of accumulated other comprehensive loss for the three months ended March 31, 2023 (in thousands): Foreign Currency Items Unrealized Gains and Losses on Marketable Debt Securities, available-for-sale Total Beginning Balance $ ( 790 ) $ ( 512 ) $ ( 1,302 ) Other comprehensive loss before reclassifications — ( 26 ) ( 26 ) Amounts reclassified from accumulated other — 352 352 Net current-period other comprehensive income — 326 326 Ending balance $ ( 790 ) $ ( 186 ) $ ( 976 )

Intangible Assets, Net

Intangible Assets, Net	3 Months Ended
	Mar. 31, 2023
Goodwill and Intangible Assets Disclosure [Abstract]
Intangible Assets, Net	4. Intangible Assets, Net I ntangible assets, net, consist of the following (in thousands, except years): For the Three Months Ended March 31, 2023 Weighted- Gross Accumulated Intangible Acquired technologies 8.6 $ 7,410 $ ( 3,257 ) $ 4,153 IPR&D 20,940 — $ 20,940 Total $ 28,350 $ ( 3,257 ) $ 25,093 I ntangible assets, net, consist of the following (in thousands, except years): For the Year Ended December 31, 2022 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 intangible assets, as more fully described within the Intangible Assets, Net subsection of Note 2—Summary of Significant Accounting Policies . The intangible asset impairment is presented in the condensed consolidated statements of operations and comprehensive loss as impairment of intangible assets within operating activities. Amortization expense for intangible assets is disclosed on the condensed consolidated statements of cash flows.

Fair Value Measurements

Fair Value Measurements	3 Months Ended
	Mar. 31, 2023
Fair Value Disclosures [Abstract]
Fair Value Measurements	6. Fair Value Measurements As of March 31, 2023 and December 31, 2022 , the Company had no assets or liabilities measured on a non-recurring basis. The following table presents the Company’s financial assets measured at fair value on a recurring basis as of March 31, 2023 (in thousands): Total Level 1 Level 2 Level 3 Cash equivalents: U.S. government securities $ 104,085 $ — $ 104,085 $ — Certificates of deposit 24,000 — 24,000 — Money market funds 17,856 17,856 — — Total cash equivalents $ 145,941 $ 17,856 $ 128,085 $ — Marketable debt securities, available-for-sale: U.S. government securities 6,467 — 6,467 — Commercial paper 1,473 — 1,473 — Total Marketable debt securities, available-for-sale $ 7,940 $ — $ 7,940 $ — Marketable debt securities, available-for-sale, net of U.S. government securities $ 6,843 $ — $ 6,843 $ — Corporate bonds 1,955 — 1,955 — Total Marketable debt securities, available-for-sale, $ 8,798 $ — $ 8,798 $ — 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 both March 31, 2023 and December 31, 2022 , the Company had no liabilities measured at fair value on a recurring basis. During the three months ended March 31, 2023 and the year ended December 31, 2022 , there were no transfers into or out of Level 3 of the fair value hierarchy.

Commitments and Contingencies

Commitments and Contingencies	3 Months Ended
	Mar. 31, 2023
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	7. Commitments and Contingencies 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 March 31, 2023 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	3 Months Ended
	Mar. 31, 2023
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 1.2 to 4.7 years. During the three months ended March 31, 2023 and the year ended December 31, 2022, the Company did not acquire any new ROU assets or lease liabilities. The components of lease expense are as follows for the three months ended March 31, 2023 and 2022 (in thousands): Three Months Ended March 31, 2023 2022 Operating lease expenses R&D: Operating lease costs $ 551 $ 558 Variable lease costs (1) 462 226 Operating lease expenses G&A: Operating lease costs 131 124 Variable lease costs (1) 110 50 Total operating leases expense $ 1,254 $ 958 ____________ (1) Includes short-term lease costs which are immaterial. Supplemental cash flow information related to leases is as follows (in thousands): Three Months Ended March 31, 2023 2022 Cash paid for amounts included in the measurement of Operating cash flows used for operating leases $ 731 $ 597 Weighted-average remaining lease term in years 4.7 5.9 Weighted-average discount rate 7.63 % 7.63 %

Shareholders' Equity

Shareholders' Equity	3 Months Ended
	Mar. 31, 2023
Convertible Preferred Ordinary Shares And Ordinary Shares [Abstract]
Shareholders' Equity	9. Shareholders' Equity Ordinary Shares In June 2021, the Company completed its initial public offering of American Depositary Shares (ADSs). Each ADS represents seven ordinary shares of the Company. At-the-Market Offering Agreement On July 29, 2022, the Company entered into a sales agreement with Cowen and Company LLC, pursuant to which the Company was able to offer and sell its ADS, 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 116,030,782 ordinary shares ( 16,575,826 ADS) at an average selling price of $ 0.69 per ordinary share ($ 4.83 per ADS), for gross proceeds of approximately $ 80.0 million, less sales commissions and expenses of approximately $ 2.2 million, for net proceeds of approximately $ 77.8 million. Accordingly, as of March 10, 2023, the ATM Program is complete. Amended and Restated Memorandum of Association Concurrent with the closing of the Company’s initial public offering in June 2021, 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	3 Months Ended
	Mar. 31, 2023
Revenue from Contract with Customer [Abstract]
Revenues	10. Revenues During the three months ended March 31, 2023 and 2022, 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 (in thousands): Three Months Ended March 31, Timing of Transfer of Goods or Services 2023 2022 Over time: License fees $ — $ 892 R&D services 6 708 Reimbursements 18 13 Point in time: Milestones — — Total revenues $ 24 $ 1,613 Remaining Performance Obligations and Deferred Revenue As of March 31, 2023, the Company had no unsatisfied remaining performance obligations for minimum full-time equivalent (FTE) services under its R&D Agreements. In addition, in each of the periods ended March 31, 2023 and December 31, 2022, the Company had deferred revenue of $ 1.7 million, 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 March 31, 2023 will be satisfied over the next 3.5 to 4.0 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. 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 milestones. 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 March 31, 2023, 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 and costs associated with Investigational New Drug (IND) 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. Sino Biopharma may terminate the Sino Agreement upon six-months ’ written notice. Under the terms of the Sino Agreement, the Company received an upfront payment of $ 10.0 million, which is no longer subject to refund. The Company is also eligible to receive milestone payments upon achievement of certain potential development and regulatory milestones for each program. In the fourth quarter of 2022, Sino completed its IND enabling activities associated with ARX102, at which time the Company fully recognized all previously deferred revenue associated with this compound. In 2022, at Sino’s request the Company has temporarily suspended development of ARX822. Since inception and through March 31, 2023, 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. Contract Assets and Liabilities Contract balances are as follows (in thousands): March 31, December 31, Receivables, included in accounts receivable, net $ 62 $ 376 Contract assets, included in prepaid expenses and other current assets $ — $ — Contract liabilities, included in deferred revenue, current and $ 1,749 $ 1,749 During the three months ended March 31, 2023 and 2022 , the Company did no t recognize any revenue from performance obligations satisfied (or partially satisfied) in previous periods.

Share-Based Compensation

Share-Based Compensation	3 Months Ended
	Mar. 31, 2023
Share-Based Payment Arrangement [Abstract]
Share-Based Compensation	11. Share-Based Compensation Share-based compensation expense was as follows (in thousands): Three Months Ended March 31, 2023 2022 Research and development $ 1,110 $ 1,050 General and administrative 828 600 Total share-based compensation expense $ 1,938 $ 1,650 The following table summarizes option activity for the periods presented (excluding options granted and canceled as part of the option repricing (discussed below): Total Weighted- Aggregate Weighted-Average Outstanding at December 31, 2022 39,116,174 $ 1.11 $ 1,088 5.4 Granted 10,151,705 $ 0.60 Canceled ( 2,546,734 ) $ 1.28 Outstanding at March 31, 2023 46,721,145 $ 0.62 $ 30,927 6.4 Vested and exercisable at 23,001,162 $ 0.87 $ 9,601 3.4 There were no options exercised during the three months ended March 31, 2023 and 2022. As of March 31, 2023, unrecognized compensation expense related to unvested share-based compensation arrangements was $ 12.8 million. These costs are expected to be recognized over a weighted-average term of 2.8 years. The weighted-average assumptions used in the Black-Scholes-Merton option pricing model to determine the fair value of option grants were as follows: For the Three Months Ended March 31, 2023 2022 Options Expected term (in years) 6.0 5.9 Risk-free interest rate 3.9 % 1.9 % Expected volatility 86.5 % 78.9 % Dividend yield — — Weighted-average grant date fair value $ 0.45 $ 0.44 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 all underwater 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, options with an exercise price above $ 0.28 per ordinary share (or the equivalent of $ 1.95 per ADS), representing an aggregate of 18,285,155 ordinary shares, or approximately 53.2 % of the total options outstanding, were amended to reduce such exercise price to $ 0.28 per ordinary share. T he Option Repricing resulted in additional compensation expense of $ 1.2 million, including $ 0.7 million that was recognized in the Company’s condensed consolidated statements of operations and comprehensive loss during the three months ended March 31, 2023. 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. 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. 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. 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. The ESPP was suspended indefinitely, effective December 16, 2022, and as of December 31, 2022 and March 31, 2023 , there was no unrecognized share-based compensation expense related to the ESPP. During the three months ended March 31, 2023 and 2022 , there were no ordinary shares issued pursuant to the ESPP.

Related Party Transactions

Related Party Transactions	3 Months Ended
	Mar. 31, 2023
Related Party Transactions [Abstract]
Related Party Transactions	12. 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): March 31, December 31, Balances: Prepaid R&D expenses $ — $ 14 Accounts payable $ 127 $ 352 Accrued liabilities $ 42 $ 99 Three Months Ended March 31, 2023 2022 Year-to-date activity: Amounts paid $ 352 $ 255 R&D expense recognized $ 84 $ 180

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policies)	3 Months Ended
	Mar. 31, 2023
Accounting Policies [Abstract]
Risk and Uncertainties	Risks and Uncertainties
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 condensed 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 March 31, 2023. While there was no material impact to the Company’s condensed consolidated financial statements as of and for the three months ended March 31, 2023 , these estimates may change, as new events occur and additional information is obtained, which could materially impact the Company’s condensed consolidated financial statements in future reporting periods.
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 Federal Deposit Insurance Corporation 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 three months ended March 31, 2023, revenues from the Company’s top two customers represented 75.0 % and 25.0 % of total revenues, respectively. During the three months ended March 31, 2022, revenues from the Company’s top three customers represented 75.6 %, 13.8 % and 10.5 % of total revenues, respectively. As of March 31, 2023, billed accounts receivable for two customers represented 73.4 % and 17.9 % of total billed receivables, respectively. As of March 31, 2022, billed accounts receivable for two customers represented 57.8 % and 40.3 % 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 condensed consolidated statements of cash flows (in thousands): Three Months Ended March 31, 2023 2022 Cash and cash equivalents $ 149,584 $ 143,631 Restricted cash 665 831 Total cash, cash equivalents, and restricted cash presented in the $ 150,249 $ 144,462 As of March 31, 2023 and 2022 , 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 March 31, 2023 and December 31, 2022 , the Company has determined an allowance for expected credit losses is not material.
Intangible Assets	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 2.8 to 11.8 years as of March 31, 2023, and three to 12 years as of December 31, 2022. Amortization expense for the Company’s finite lived intangible assets is charged to research and development expense in the condensed 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. 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. 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. 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. There were no impairment charges recognized during the three months ended March 31, 2023 .
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 46,721,145 and 39,754,803 ordinary shares for the three months ended March 31, 2023 and 2022 , respectively.
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 condensed consolidated financial statements upon adoption.

Summary of Significant Accoun_3

Summary of Significant Accounting Policies (Tables)	3 Months Ended
	Mar. 31, 2023
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 condensed consolidated statements of cash flows (in thousands): Three Months Ended March 31, 2023 2022 Cash and cash equivalents $ 149,584 $ 143,631 Restricted cash 665 831 Total cash, cash equivalents, and restricted cash presented in the $ 150,249 $ 144,462

Marketable Debt Securities, A_2

Marketable Debt Securities, Available-for-Sale (Tables)	3 Months Ended
	Mar. 31, 2023
Investments, Debt and Equity Securities [Abstract]
Schedule of Available-for-Sale Securities Reconciliation	The following table summarizes the Company’s MDS as of March 31, 2023 (dollars in thousands): Weighted Amortized Unrealized Unrealized Fair Classified as current assets: U.S. government securities 1 or less $ 6,479 $ 1 $ ( 13 ) $ 6,467 Commercial paper 1 or less 1,473 — — 1,473 Total Marketable debt securities, 1 or less $ 7,952 $ 1 $ ( 13 ) $ 7,940 Classified as non-current assets: U.S. government securities 1.1 $ 6,983 $ — $ ( 140 ) $ 6,843 Corporate bonds 1.2 1,989 — ( 34 ) 1,955 Total Marketable debt securities, 1.2 $ 8,972 $ — $ ( 174 ) $ 8,798 Total 0.7 $ 16,924 $ 1 $ ( 187 ) $ 16,738 The following table summarizes the Company’s MDS as of December 31, 2022 (dollars in thousands): Weighted 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 Gross Unrealized Losses and Fair Values on Debt Securities Classified as Available-for Sale	The following tables present gross unrealized losses and fair values for those investments that were in an unrealized loss position as of March 31, 2023 and December 31, 2022, aggregated by investment category for MDS that have been in a continuous loss position for less than 12 months and for more than 12 months (in thousands): Less than 12 months More than 12 months Estimated Gross Estimated Gross March 31, 2023 U.S. government securities $ 9,832 $ ( 153 ) $ — $ — Corporate bonds 1,955 ( 34 ) — — Total $ 11,787 $ ( 187 ) $ — $ — December 31, 2022 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 ) $ — $ —

Balance Sheets Details (Tables)

Balance Sheets Details (Tables)	3 Months Ended
	Mar. 31, 2023
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 (in thousands): March 31, December 31, Tax receivable $ 2,062 $ 1,506 Prepaid R&D costs 1,286 1,476 Prepaid insurance and service contracts 913 1,424 Interest receivable - MDS 192 168 Other 238 319 Total $ 4,691 $ 4,893
Schedule of property and equipment	Property and equipment, net, consist of the following (in thousands): March 31, December 31, Laboratory equipment $ 7,597 $ 7,559 Computers, software and office equipment 512 512 Leasehold improvements 467 467 Office furniture and fixtures 123 123 8,699 8,661 Accumulated depreciation and amortization ( 5,810 ) ( 5,617 ) Total $ 2,889 $ 3,044
Schedule of Accrued Liabilities	Accrued liabilities consist of the following (in thousands): March 31, December 31, Accrued R&D costs (1) $ 2,065 $ 4,069 Accrued compensation 1,593 3,494 Accrued audit, tax and filing fees 1,917 1,703 Accrued directors and officers insurance premium (2) 372 926 Accrued other 835 1,122 Total $ 6,782 $ 11,314 (1) Includes $ 42 and $ 99 of accrued R&D costs due to related parties as of March 31, 2023 and December 31, 2022 , 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.
Schedule of Reconciliation of Components of Accumulated Other Comprehensive Loss	The following table provides a reconciliation of the components of accumulated other comprehensive loss for the three months ended March 31, 2023 (in thousands): Foreign Currency Items Unrealized Gains and Losses on Marketable Debt Securities, available-for-sale Total Beginning Balance $ ( 790 ) $ ( 512 ) $ ( 1,302 ) Other comprehensive loss before reclassifications — ( 26 ) ( 26 ) Amounts reclassified from accumulated other — 352 352 Net current-period other comprehensive income — 326 326 Ending balance $ ( 790 ) $ ( 186 ) $ ( 976 )

Intangible Assets, Net (Tables)

Intangible Assets, Net (Tables)	3 Months Ended
	Mar. 31, 2023
Goodwill and Intangible Assets Disclosure [Abstract]
Schedule of Intangible Assets	ntangible assets, net, consist of the following (in thousands, except years): For the Three Months Ended March 31, 2023 Weighted- Gross Accumulated Intangible Acquired technologies 8.6 $ 7,410 $ ( 3,257 ) $ 4,153 IPR&D 20,940 — $ 20,940 Total $ 28,350 $ ( 3,257 ) $ 25,093 I ntangible assets, net, consist of the following (in thousands, except years): For the Year Ended December 31, 2022 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 intangible assets, as more fully described within the Intangible Assets, Net subsection of Note 2—Summary of Significant Accounting Policies . The intangible asset impairment is presented in the condensed consolidated statements of operations and comprehensive loss as impairment of intangible assets within operating activities.

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	3 Months Ended
	Mar. 31, 2023
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 March 31, 2023 (in thousands): Total Level 1 Level 2 Level 3 Cash equivalents: U.S. government securities $ 104,085 $ — $ 104,085 $ — Certificates of deposit 24,000 — 24,000 — Money market funds 17,856 17,856 — — Total cash equivalents $ 145,941 $ 17,856 $ 128,085 $ — Marketable debt securities, available-for-sale: U.S. government securities 6,467 — 6,467 — Commercial paper 1,473 — 1,473 — Total Marketable debt securities, available-for-sale $ 7,940 $ — $ 7,940 $ — Marketable debt securities, available-for-sale, net of U.S. government securities $ 6,843 $ — $ 6,843 $ — Corporate bonds 1,955 — 1,955 — Total Marketable debt securities, available-for-sale, $ 8,798 $ — $ 8,798 $ — 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)	3 Months Ended
	Mar. 31, 2023
Lessee Disclosure [Abstract]
Summary of Components of Operating Lease Expense	The components of lease expense are as follows for the three months ended March 31, 2023 and 2022 (in thousands): Three Months Ended March 31, 2023 2022 Operating lease expenses R&D: Operating lease costs $ 551 $ 558 Variable lease costs (1) 462 226 Operating lease expenses G&A: Operating lease costs 131 124 Variable lease costs (1) 110 50 Total operating leases expense $ 1,254 $ 958 ____________ Includes short-term lease costs which are immaterial.
Summary of Supplemental cash flow information related to leases	Supplemental cash flow information related to leases is as follows (in thousands): Three Months Ended March 31, 2023 2022 Cash paid for amounts included in the measurement of Operating cash flows used for operating leases $ 731 $ 597 Weighted-average remaining lease term in years 4.7 5.9 Weighted-average discount rate 7.63 % 7.63 %

Revenues (Tables)

Revenues (Tables)	3 Months Ended
	Mar. 31, 2023
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 (in thousands): Three Months Ended March 31, Timing of Transfer of Goods or Services 2023 2022 Over time: License fees $ — $ 892 R&D services 6 708 Reimbursements 18 13 Point in time: Milestones — — Total revenues $ 24 $ 1,613
Contract with Customer, Contract Asset, Contract Liability, and Receivable	Contract balances are as follows (in thousands): March 31, December 31, Receivables, included in accounts receivable, net $ 62 $ 376 Contract assets, included in prepaid expenses and other current assets $ — $ — Contract liabilities, included in deferred revenue, current and $ 1,749 $ 1,749

Share-Based Compensation (Table

Share-Based Compensation (Tables)	3 Months Ended
	Mar. 31, 2023
Share-Based Payment Arrangement [Abstract]
Summary of Share-based Compensation Expense	Share-based compensation expense was as follows (in thousands): Three Months Ended March 31, 2023 2022 Research and development $ 1,110 $ 1,050 General and administrative 828 600 Total share-based compensation expense $ 1,938 $ 1,650
Summary of Option Activity Excluding Options Granted and Canceled as Part of Option Repricing	The following table summarizes option activity for the periods presented (excluding options granted and canceled as part of the option repricing (discussed below): Total Weighted- Aggregate Weighted-Average Outstanding at December 31, 2022 39,116,174 $ 1.11 $ 1,088 5.4 Granted 10,151,705 $ 0.60 Canceled ( 2,546,734 ) $ 1.28 Outstanding at March 31, 2023 46,721,145 $ 0.62 $ 30,927 6.4 Vested and exercisable at 23,001,162 $ 0.87 $ 9,601 3.4
Summary Of Share Based Payment Award Stock Options Valuation Assumptions	The weighted-average assumptions used in the Black-Scholes-Merton option pricing model to determine the fair value of option grants were as follows: For the Three Months Ended March 31, 2023 2022 Options Expected term (in years) 6.0 5.9 Risk-free interest rate 3.9 % 1.9 % Expected volatility 86.5 % 78.9 % Dividend yield — — Weighted-average grant date fair value $ 0.45 $ 0.44

Related Party Transactions (Tab

Related Party Transactions (Tables)	3 Months Ended
	Mar. 31, 2023
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): March 31, December 31, Balances: Prepaid R&D expenses $ — $ 14 Accounts payable $ 127 $ 352 Accrued liabilities $ 42 $ 99 Three Months Ended March 31, 2023 2022 Year-to-date activity: Amounts paid $ 352 $ 255 R&D expense recognized $ 84 $ 180

Description of Business and B_2

Description of Business and Basis of Presentation - Additional Information (Detail) - USD ($) $ in Thousands	Mar. 31, 2023	Dec. 31, 2022
Organization Consolidation And Presentation Of Financial Statements [Line Items]
Retained earnings accumulated deficit	$ (306,930)	$ (291,628)
Non-current marketable debt securities	8,798	$ 16,793
Liquidity and Capital Resources [Member]
Organization Consolidation And Presentation Of Financial Statements [Line Items]
Retained earnings accumulated deficit	306,900
Cash and cash equivalents and marketable debt securities	166,300
Non-current marketable debt securities	$ 8,800
Shangai Ambrx Biomedical Company Limited [Member]
Organization Consolidation And Presentation Of Financial Statements [Line Items]
Equity method investment ownership percentage	100%
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 ($)		3 Months Ended		12 Months Ended
	Feb. 03, 2022	Mar. 31, 2023	Mar. 31, 2022	Dec. 31, 2022
Impairment of intangible assets		$ 0	$ 2,465,000	$ 9,660,000
Impairment of Intangible Assets, Indefinite-Lived (Excluding Goodwill)		$ 0
BMS Relax in Agreement [Member]
Impairment of intangible assets	$ 2,500,000
Technology-Based Intangible Assets [Member]
Impairment of intangible assets				$ 9,660,000
Maximum [Member] | Technology-Based Intangible Assets [Member]
Finite Lived Intangible Asset Remaining Useful Life		11 years 9 months 18 days		12 years
Minimum [Member] | Technology-Based Intangible Assets [Member]
Finite Lived Intangible Asset Remaining Useful Life		2 years 9 months 18 days		3 years
Share-based Payment Arrangement, Option [Member]
Antidilutive securities excluded from computation of Earnings per share, Amount		46,721,145	39,754,803
First Customer From Top Three Customer [Member] | Customer Concentration Risk [Member] | Revenue Benchmark [Member]
Concentration risk, percentage		75%	75.60%
Second Customer From Top Three Customer [Member] | Customer Concentration Risk [Member] | Revenue Benchmark [Member]
Concentration risk, percentage		25%	13.80%
Third Customer From Top Three Customer [Member] | Customer Concentration Risk [Member] | Revenue Benchmark [Member]
Concentration risk, percentage			10.50%
First Customer [Member] | Customer Concentration Risk [Member] | Accounts Receivable [Member]
Concentration risk, percentage		73.40%	57.80%
Second Customer [Member] | Customer Concentration Risk [Member] | Accounts Receivable [Member]
Concentration risk, percentage		17.90%	40.30%

Summary of Significant Accoun_5

Summary of Significant Accounting Policies - Schedule of Cash, Cash Equivalents and Restricted Cash (Detail) - USD ($) $ in Thousands	Mar. 31, 2023	Dec. 31, 2022	Mar. 31, 2022	Dec. 31, 2021
Cash, Cash Equivalents, Restricted Cash, and Restricted Cash Equivalents [Abstract]
Cash and cash equivalents	$ 149,584		$ 143,631
Restricted cash	665	$ 831	831
Total cash, cash equivalents, and restricted cash presented in the condensed consolidated statements of cash flows	$ 150,249	$ 56,441	$ 144,462	$ 170,906

Marketable Debt Securities, A_3

Marketable Debt Securities, Available-for-Sale - Schedule of Available-for-Sale Securities Reconciliation (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2023	Dec. 31, 2022
Debt Securities, Available-for-Sale [Line Items]
Weighted-Average Remaining Contractual Life (in years)	8 months 12 days	8 months 12 days
Amortized Costs	$ 16,924	$ 46,175
Gross Unrealized Gains	1	3
Gross Unrealized Losses	(187)	(512)
Fair Value	16,738	45,666
Due Greater than 90 Days and Less than One Year [Member]
Debt Securities, Available-for-Sale [Line Items]
Amortized Costs	7,952	28,950
Gross Unrealized Gains	1	3
Gross Unrealized Losses	(13)	(80)
Fair Value	$ 7,940	$ 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	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	$ 6,479	$ 5,001
Gross Unrealized Gains	1
Gross Unrealized Losses	(13)	(30)
Fair Value	$ 6,467	$ 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	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	$ 1,473	$ 15,803
Gross Unrealized Gains		1
Gross Unrealized Losses		(23)
Fair Value	$ 1,473	$ 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	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] | 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 One to Two Years [Member]
Debt Securities, Available-for-Sale [Line Items]
Weighted-Average Remaining Contractual Life (in years)	1 year 2 months 12 days	1 year 6 months
Amortized Costs	$ 8,972	$ 17,225
Gross Unrealized Losses	(174)	(432)
Fair Value	$ 8,798	$ 16,793
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 1 month 6 days	1 year 4 months 24 days
Amortized Costs	$ 6,983	$ 6,979
Gross Unrealized Losses	(140)	(184)
Fair Value	$ 6,843	$ 6,795
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 2 months 12 days	1 year 6 months
Amortized Costs	$ 1,989	$ 6,824
Gross Unrealized Losses	(34)	(192)
Fair Value	$ 1,955	$ 6,632
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 US 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)	3 Months Ended
	Mar. 31, 2023 USD ($) Security	Mar. 31, 2022 USD ($)	Dec. 31, 2022 USD ($)
Debt Securities, Available-for-Sale [Line Items]
Fair Value	$ 16,738,000		$ 45,666,000
Interest receivable	$ 192,000		$ 168,000
Unrealized loss position of securities | Security	7
Debt securities, available-for-sale, realized gain loss	$ 400,000	$ 0

Marketable Debt Securities, A_5

Marketable Debt Securities, Available-for-Sale - Schedule of Gross Unrealized Losses and Fair Values on Debt Securities Classified as Available-for Sale (Details) - USD ($) $ in Thousands	Mar. 31, 2023	Dec. 31, 2022
Debt Securities, Available-for-Sale [Line Items]
Less than 12 Months, Estimated Fair Value	$ 11,787	$ 38,185
Less than 12 Months, Gross Unrealized Losses	(187)	(512)
More than 12 Months, Estimated Fair Value	0	0
More than 12 Months, Gross Unrealized Losses	0	0
US Government Debt Securities [Member]
Debt Securities, Available-for-Sale [Line Items]
Less than 12 Months, Estimated Fair Value	9,832	11,765
Less than 12 Months, Gross Unrealized Losses	(153)	(216)
More than 12 Months, Estimated Fair Value	0	0
More than 12 Months, Gross Unrealized Losses	0	0
Corporate Debt Securities [Member]
Debt Securities, Available-for-Sale [Line Items]
Less than 12 Months, Estimated Fair Value	1,955	7,276
Less than 12 Months, Gross Unrealized Losses	(34)	(193)
More than 12 Months, Estimated Fair Value	0	0
More than 12 Months, Gross Unrealized Losses	$ 0	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
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
Debt Security, Government, Non-US [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

Balance Sheets Details - Schedu

Balance Sheets Details - Schedule of Prepaid Expenses and Other Current Assets (Detail) - USD ($) $ in Thousands	Mar. 31, 2023	Dec. 31, 2022
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]
Tax receivable	$ 2,062	$ 1,506
Prepaid R&D costs	1,286	1,476
Prepaid insurance and service contracts	913	1,424
Interest receivable - MDS	192	168
Other	238	319
Total	$ 4,691	$ 4,893

Balance Sheets Details - Sche_2

Balance Sheets Details - Schedule of Property and Equipment, Net (Detail) - USD ($) $ in Thousands	Mar. 31, 2023	Dec. 31, 2022
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	$ 8,699	$ 8,661
Accumulated depreciation and amortization	(5,810)	(5,617)
Total	2,889	3,044
Laboratory equipment [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	7,597	7,559
Computers, software and office equipment [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	512	512
Leasehold improvements [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	467	467
Office furniture and fixtures [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	$ 123	$ 123

Balance Sheets Details - Sche_3

Balance Sheets Details - Schedule of Accrued Liabilities (Detail) - USD ($) $ in Thousands	Mar. 31, 2023	Dec. 31, 2022
Payables and Accruals [Abstract]
Accrued R&D costs	$ 2,065	$ 4,069
Accrued compensation	1,593	3,494
Accrued audit, tax and filing fees	1,917	1,703
Accrued directors and officers insurance premium financing obligation	372	926
Accrued other	835	1,122
Total	$ 6,782	$ 11,314

Balance Sheets Details - Sche_4

Balance Sheets Details - Schedule of Accrued Liabilities (Parenthetical) (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2023	Dec. 31, 2022
Payables and Accruals [Line Items]
Accrued research and development costs related party	$ 42	$ 99
Insurance Premium Financing Agreement [Member]
Payables and Accruals [Line Items]
Debt instrument interest rate during period	3.40%

Balance Sheets Details - Sche_5

Balance Sheets Details - Schedule of Reconciliation of Components of Accumulated Other Comprehensive Loss (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance	$ 117,850	$ 189,967
Other comprehensive loss before reclassifications	(26)	0
Amounts reclassified from accumulated other comprehensive loss	352	0
Total other comprehensive income	326	0
Ending balance	182,592	168,977
Foreign Currency Items [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance	(790)
Ending balance	(790)
Unrealized Gains and Losses on Marketable Debt Securities, Available-for-sale [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance	(512)
Other comprehensive loss before reclassifications	(26)
Amounts reclassified from accumulated other comprehensive loss	352
Total other comprehensive income	326
Ending balance	(186)
Total [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance	(1,302)	(790)
Other comprehensive loss before reclassifications	(26)
Amounts reclassified from accumulated other comprehensive loss	352
Total other comprehensive income	326
Ending balance	$ (976)	$ (790)

Intangible Assets, Net - Schedu

Intangible Assets, Net - Schedule of Intangible Assets (Detail) - USD ($) $ in Thousands	3 Months Ended		12 Months Ended
	Mar. 31, 2023	Mar. 31, 2022	Dec. 31, 2022
Schedule Of Intangible Assets Net Excluding Goodwill [Line Items]
Gross Carrying Amount	$ 28,350		$ 45,270
Impairment of intangible assets	0	$ (2,465)	(9,660)
Accumulated Amortization	(3,257)		(10,360)
Intangible Assets, Net	25,093		25,250
IPR&D [Member]
Schedule Of Intangible Assets Net Excluding Goodwill [Line Items]
Gross Carrying Amount	20,940		20,940
Impairment of intangible assets			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 7 months 6 days		8 years 9 months 18 days
Gross Carrying Amount	$ 7,410		$ 24,330
Impairment of intangible assets			(9,660)
Accumulated Amortization	(3,257)		(10,360)
Intangible Assets, Net	$ 4,153		$ 4,310

Fair Value Measurements - Addit

Fair Value Measurements - Additional Information (Detail) - USD ($)	3 Months Ended	12 Months Ended
	Mar. 31, 2023	Dec. 31, 2022
Fair Value, Recurring [Member]
Liabilities, fair value disclosure	$ 0	$ 0
Fair value liability, transfers out of level 3	0	0
Fair Value, Nonrecurring [Member]
Assets, fair value disclosure	0	0
Liabilities, fair value disclosure	$ 0	$ 0

Fair Value Measurements - Sched

Fair Value Measurements - Schedule Of Fair Value Assets And Liabilities Measured On Recurring Basis (Detail) - USD ($) $ in Thousands	Mar. 31, 2023	Dec. 31, 2022
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt Securities, Available-for-Sale, Current	$ 7,940	$ 28,873
Debt Securities, Available-for-Sale, Noncurrent	8,798	16,793
Fair Value, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and Cash Equivalents, Fair Value Disclosure	145,941	52,095
Debt Securities, Available-for-Sale, Current	7,940	28,873
Debt Securities, Available-for-Sale, Noncurrent	8,798	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	17,856	12,743
Debt Securities, Available-for-Sale, Current	0	0
Debt Securities, Available-for-Sale, Noncurrent	0	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	128,085	39,352
Debt Securities, Available-for-Sale, Current	7,940	28,873
Debt Securities, Available-for-Sale, Noncurrent	8,798	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	0
Debt Securities, Available-for-Sale, Current	0	0
Debt Securities, Available-for-Sale, Noncurrent	0	0
Fair Value, Recurring [Member] | US Government Debt Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and Cash Equivalents, Fair Value Disclosure	104,085
Debt Securities, Available-for-Sale, Current	6,467	4,971
Debt Securities, Available-for-Sale, Noncurrent	6,843	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]
Cash and Cash Equivalents, Fair Value Disclosure	0
Debt Securities, Available-for-Sale, Current	0	0
Debt Securities, Available-for-Sale, Noncurrent	0	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]
Cash and Cash Equivalents, Fair Value Disclosure	104,085
Debt Securities, Available-for-Sale, Current	6,467	4,971
Debt Securities, Available-for-Sale, Noncurrent	6,843	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]
Cash and Cash Equivalents, Fair Value Disclosure	0
Debt Securities, Available-for-Sale, Current	0	0
Debt Securities, Available-for-Sale, Noncurrent	0	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	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	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	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	0
Debt Securities, Available-for-Sale, Current		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	1,473	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	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	1,473	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	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	17,856	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	17,856	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	0	0
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	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	1,955	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	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	1,955	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	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] | 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

Leases - Summary of Components

Leases - Summary of Components of Operating Lease Expense (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Lessee, Lease, Description [Line Items]
Total operating leases expense	$ 1,254	$ 958
Operating lease expenses R&D [Member]
Lessee, Lease, Description [Line Items]
Operating lease costs	551	558
Variable lease costs	462	226
Operating lease expenses G&A [Member]
Lessee, Lease, Description [Line Items]
Operating lease costs	131	124
Variable lease costs	$ 110	$ 50

Leases - Summary of Supplementa

Leases - Summary of Supplemental cash flow information related to leases (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Cash paid for amounts included in the measurement of lease liabilities:
Operating cash flows used for operating leases	$ 731	$ 597
Weighted-average remaining lease term in years	4 years 8 months 12 days	5 years 10 months 24 days
Weighted-average discount rate	7.63%	7.63%

Leases - Additional Information

Leases - Additional Information (Detail)	Mar. 31, 2023
Maximum [Member]
Lessee, Lease, Description [Line Items]
Operating lease remaining lease term	4 years 8 months 12 days
Minimum [Member]
Lessee, Lease, Description [Line Items]
Operating lease remaining lease term	1 year 2 months 12 days

Shareholders' Equity - Addition

Shareholders' Equity - Additional Information (Detail) $ / shares in Units, $ in Thousands		3 Months Ended
	Jul. 29, 2022 USD ($)	Mar. 31, 2023 USD ($) $ / shares shares	Mar. 31, 2022 USD ($) shares	Feb. 28, 2023 shares	Dec. 31, 2022 shares	Jun. 30, 2021 shares
Convertible Preferred Ordinary Shares And Ordinary Shares [Line Items]
Common stock shares outstanding		386,486,014			270,455,232
Net proceeds from the issuance of common stock | $		$ 77,780	$ 7
Common stock shares authorized		600,000,000		600,000,000	500,000,000
Preferred stock shares issued					0
Preferred stock shares outstanding					0
Issuance of ordinary shares		0	0
Restated Memorandum And Articles Of Association [Member]
Convertible Preferred Ordinary Shares And Ordinary Shares [Line Items]
Common stock shares authorized						500,000,000
Preferred stock shares authorized						100,000,000
Common Stock [Member]
Convertible Preferred Ordinary Shares And Ordinary Shares [Line Items]
Stock shares issued during the period shares		116,030,782	6,398
ATM Offering Program [Member]
Convertible Preferred Ordinary Shares And Ordinary Shares [Line Items]
Gross proceeds from issuance of common stock including sales commissions | $		$ 80,000
Commission on sale of common stock | $		2,200
Net proceeds from the issuance of common stock | $		$ 77,800
ATM Offering Program [Member] | Maximum [Member]
Convertible Preferred Ordinary Shares And Ordinary Shares [Line Items]
Aggregate offering price | $	$ 80,000
ATM Offering Program [Member] | Common Stock [Member]
Convertible Preferred Ordinary Shares And Ordinary Shares [Line Items]
Entity listing depository receipt ratio	7
Shares issued and sold during the period shares		116,030,782
Average stock price per share | $ / shares		$ 0.69
ADR [Member] | ATM Offering Program [Member]
Convertible Preferred Ordinary Shares And Ordinary Shares [Line Items]
Shares issued and sold during the period shares		16,575,826
Average stock price per share | $ / shares		$ 4.83

Revenues - Schedule of Revenue

Revenues - Schedule of Revenue Recognized (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Disaggregation of Revenue [Line Items]
Revenue from contract with customer, excluding assessed tax	$ 24	$ 1,613
License Fees [Member] | Over Time [Member]
Disaggregation of Revenue [Line Items]
Revenue from contract with customer, excluding assessed tax	0	892
Reimbursements [Member] | Over Time [Member]
Disaggregation of Revenue [Line Items]
Revenue from contract with customer, excluding assessed tax	18	13
Milestones [Member] | Point in Time [Member]
Disaggregation of Revenue [Line Items]
Revenue from contract with customer, excluding assessed tax	0	0
Research And Development Services [Member] | Over Time [Member]
Disaggregation of Revenue [Line Items]
Revenue from contract with customer, excluding assessed tax	$ 6	$ 708

Revenues - Additional Informati

Revenues - Additional Information (Detail)	1 Months Ended			3 Months Ended
	Jan. 31, 2020 USD ($) Patients	Oct. 31, 2019 USD ($) FullTimeEquivalentServices	Mar. 31, 2019 USD ($)	Mar. 31, 2023 USD ($)	Mar. 31, 2022 USD ($)	Dec. 31, 2022 USD ($)
Disaggregation of Revenue [Line Items]
Performance obligations remaining amount				$ 0
Revenue from Contract with Customer, Excluding Assessed Tax				24,000	$ 1,613,000
Revenue from performance obligations of the previous period recognized				0	$ 0
Deferred Revenue				$ 1,700,000		$ 1,700,000
Bigene Limited [Member]
Disaggregation of Revenue [Line Items]
Upfront payment received towards license fees			$ 10,000,000
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
Initial research term extension period				2 years
Novocodex [Member] | Point in Time [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax				$ 1,000,000
Novocodex [Member] | Development and Commercialization Agreement [Member]
Disaggregation of Revenue [Line Items]
Upfront payment received towards license fees		$ 2,000,000
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]
Disaggregation of Revenue [Line Items]
Upfront payment received towards license fees	$ 10,000,000
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				3 years 6 months
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

Revenues - Schedule of the Cont

Revenues - Schedule of the Contract Balances (Detail) - USD ($) $ in Thousands	Mar. 31, 2023	Dec. 31, 2022
Revenue from Contract with Customer [Abstract]
Receivables, included in accounts receivable, net	$ 62	$ 376
Contract assets, included in prepaid expenses and other current assets	0	0
Contract liabilities included in deferred revenue, current and deferred revenue net of current portion	$ 1,749	$ 1,749

Share-Based Compensation - Summ

Share-Based Compensation - Summary of Share-based Compensation Expense (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Share-Based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Allocated share based compensation expense	$ 1,938	$ 1,650
Research and Development Expense [Member]
Share-Based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Allocated share based compensation expense	1,110	1,050
General and Administrative [Member]
Share-Based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Allocated share based compensation expense	$ 828	$ 600

Share-Based Compensation - Su_2

Share-Based Compensation - Summary of Option Activity Excluding Options Granted and Canceled as Part of Option Repricing (Detail) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2023	Dec. 31, 2022
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Beginning balance, Total Options	39,116,174
Total Options, Granted	10,151,705
Total Options, Cancelled	(2,546,734)
Ending balance, Total Options	46,721,145	39,116,174
Vested and exercisable share	23,001,162
Beginning balance, Weighted Average Exercise Price	$ 1.11
Weighted Average Exercise Price, Granted	0.60
Weighted Average Exercise Price, Cancelled	1.28
Ending balance, Weighted Average Exercise Price	0.62	$ 1.11
Weighted Average Exercise Price, Vested and Exercisable	$ 0.87
Aggregate Intrinsic Value, Outstanding	$ 30,927	$ 1,088
Aggregate Intrinsic Value, Vested and Exercisable	$ 9,601
Weighted Average Remaining Contractual Term, Outstanding	6 years 4 months 24 days	5 years 4 months 24 days
Weighted Average Remaining Contractual Life, Vested and Exercisable	3 years 4 months 24 days

Share-Based Compensation - Addi

Share-Based Compensation - Additional Information (Detail)			3 Months Ended		12 Months Ended
	Jan. 27, 2023 $ / shares shares	Jan. 01, 2023 shares	Mar. 31, 2023 USD ($) Offering $ / shares shares	Mar. 31, 2022 USD ($) $ / shares shares	Dec. 31, 2022 USD ($)
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Issuance of ordinary shares upon exercise of options (in shares) | shares			0	0
Allocated share based compensation expense			$ 1,938,000	$ 1,650,000
Weighted average exercise price, granted | $ / shares			$ 0.60
Net proceeds from the issuance of common stock			$ 77,780,000	7,000
Aggregate Intrinsic Value, Outstanding			30,927,000		$ 1,088,000
Share based payment arrangement nonvested award cost not yet recognized period for recognition			$ 12,800,000
Share-based payment arrangement, nonvested award, cost not yet recognized, period for recognition			2 years 9 months 18 days
Share-based compensation expense			$ 1,938,000	$ 1,650,000
Share-Based Payment Arrangement, Option [Member]
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Weighted average grant date fair values | $ / shares			$ 0.45	$ 0.44
Option Repricing Program [Member]
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Allocated share based compensation expense			$ 1,200,000
Ordinary shares repriced shares outstanding | shares	18,285,155
exercise price | $ / shares	$ 0.28
Weighted average exercise price, granted | $ / shares	$ 0.28
Ordinary shares repriced as a percentage of options outstanding	53.20%
Option Repricing Program [Member] | Statements of Operations and Comprehensive Loss [Member]
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Allocated share based compensation expense			$ 700,000
American Depositary Shares [Member] | Option Repricing Program [Member]
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
exercise price | $ / shares	$ 1.95
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%
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 | shares		8,405,757
Issuance of ordinary shares for cash (in shares) | shares			0	0
Share-based compensation arrangement by share-based payment award, number of additional shares authorized | shares		2,704,552
Share-based compensation expense			$ 0		$ 0

Share-Based Compensation - Su_3

Share-Based Compensation - Summary of Share Based Payment Award Stock Options Valuation Assumptions (Detail) - Employee Stock Option - $ / shares	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Expected term (in years)	6 years	5 years 10 months 24 days
Risk-free interest rate	3.90%	1.90%
Expected volatility	86.50%	78.90%
Weighted average grant date fair values	$ 0.45	$ 0.44

Income Taxes - Schedule Of Loss

Income Taxes - Schedule Of Loss Before Income Tax (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Loss before income taxes	$ (15,229)	$ (21,060)

Income Taxes - Schedule of Comp

Income Taxes - Schedule of Components of Income Tax Expense (Benefit) (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Deferred:
Total provision for (benefit from) income taxes	$ 73	$ 1,587

Related Party Transactions - Su

Related Party Transactions - Summary of Activities with Affiliates of the Non Controlling Shareholders (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022	Dec. 31, 2022
Related Party Transaction [Line Items]
Prepaid R&D expenses			$ 14
Accounts payable	$ 127		352
Accrued liabilities	42		$ 99
Amounts paid	352	$ 255
R&D expense recognized	$ 84	$ 180