eFFECTOR Therapeutics (EFTR) POS AM 17 Mar 22 Prospectus update (post-effective amendment) Financial data

Cover Page

Cover Page	12 Months Ended
	Dec. 31, 2021
Document Information [Line Items]
Document Type	POS AM
Amendment Flag	true
Entity Registrant Name	eFFECTOR Therapeutics, Inc.
Entity Central Index Key	0001828522
Entity Filer Category	Non-accelerated Filer
Entity Small Business	true
Entity Emerging Growth Company	true
Entity Ex Transition Period	false
Amendment Description	This Post-Effective Amendment No. 1 (this “Post-Effective Amendment No. 1”) to the Registration Statement on Form S-1 (File No. 333-259751) (the “Registration Statement”), as originally declared effective by the Securities and Exchange Commission (the “SEC”) on October 5, 2021, is being filed to include information contained in the registrant’s Annual Report on Form 10-K for the fiscal year ended December 31, 2021, which was filed with the SEC on March 16, 2022, and to update certain other information in the Registration Statement. The information included in this filing amends the Registration Statement and the prospectus contained therein. No additional securities are being registered under this Post-Effective Amendment No. 1. All applicable registration fees were paid at the time of the original filing of the Registration Statement on September 23, 2021.

Balance Sheets

Balance Sheets - USD ($) $ in Thousands		Dec. 31, 2021	Dec. 31, 2020
Current assets:
Cash and cash equivalents		$ 49,702	$ 15,216
Prepaid expenses and other current assets		3,194	1,362
Total current assets		52,896	16,578
Property and equipment, net		91	34
Operating lease right-of-use assets		166	92
Other assets		903	0
Total assets		54,056	16,704
Current liabilities:
Accounts payable		516	347
Accrued expenses		3,418	1,984
Warrant Liability		0	433
Term loans, net		0	5,907
Lease liabilities, current portion		44	108
Total current liabilities		3,978	8,779
Earn-out liability		12,130	0
Non-current term loans, net		18,760	6,946
Accrued final payment on term loans		1,100	0
Non-current warrant liability		678	0
Non-current lease liabilities		126	0
Total liabilities		36,772	15,725
Commitments and Contingencies
Stockholders' deficit:
Preferred stock		0	0
Common stock		4	0
Additional paid-in capital		138,181	4,454
Accumulated deficit		(120,901)	(136,699)
Total stockholders' equity (deficit)	[1]	17,284	(132,245)
Total liabilities, convertible preferred stock, and stockholders' equity (deficit)		54,056	16,704
Series A Convertible Preferred Stock [Member]
Current liabilities:
Convertible preferred stock		0	46,567
Series B Convertible Preferred Stock [Member]
Current liabilities:
Convertible preferred stock		0	51,084
Series C Convertible Preferred Stock [Member]
Current liabilities:
Convertible preferred stock		$ 0	$ 35,573
[1]	Historical shares and capital amounts have been retroactively restated for the reverse recapitalization as described in Note 1.

Balance Sheets (Parenthetical)

Balance Sheets (Parenthetical) - USD ($) $ in Thousands		Dec. 31, 2021	Dec. 31, 2020
Preferred stock, par value		$ 0.0001	$ 0.0001
Preferred stock, shares authorized		100,000,000	0
Preferred stock, shares issued		0	0
Preferred stock, shares outstanding		0	0
Common stock, par value		$ 0.0001	$ 0.0001
Common stock, shares authorized		1,000,000,000	37,669,357
Common stock, shares issued		40,689,975	1,445,065
Common stock, shares outstanding		40,389,975	1,445,065
Temporary Equity, Shares Authorized		32,474,428
Temporary Equity, Shares Outstanding		28,453,228
Temporary Equity, Liquidation Preference		$ 134,087
Series A Convertible Preferred Stock [Member]
Temporary Equity, Par or Stated Value Per Share		$ 0.0001	$ 0.0001
Temporary Equity, Shares Authorized		0	14,056,840
Temporary Equity, Shares Issued		0	11,563,819
Temporary Equity, Shares Outstanding	[1]	0	11,563,819
Temporary Equity, Liquidation Preference		$ 0	$ 46,878
Series B Convertible Preferred Stock [Member]
Temporary Equity, Par or Stated Value Per Share		$ 0.0001	$ 0.0001
Temporary Equity, Shares Authorized		0	11,071,448
Temporary Equity, Shares Issued		0	10,154,819
Temporary Equity, Shares Outstanding	[1]	0	10,154,819
Temporary Equity, Liquidation Preference		$ 0	$ 51,364
Series C Convertible Preferred Stock [Member]
Temporary Equity, Par or Stated Value Per Share		$ 0.0001	$ 0.0001
Temporary Equity, Shares Authorized		0	7,346,140
Temporary Equity, Shares Issued		0	6,734,590
Temporary Equity, Shares Outstanding	[1]	0	6,734,590
Temporary Equity, Liquidation Preference		$ 0	$ 35,845
[1]	Historical shares and capital amounts have been retroactively restated for the reverse recapitalization as described in Note 1.

Consolidated Statements of Oper

Consolidated Statements of Operations and Comprehensive Income - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2021	Dec. 31, 2020
Collaboration revenue		$ 0	$ 42,000
Grant revenue		1,430	0
Total revenue		1,430	42,000
Operating expenses:
Research and development		19,956	21,832
General and administrative		13,371	4,349
Total operating expenses		33,327	26,181
Operating (loss) income		(31,897)	15,819
Other income (expense)
Interest income		6	67
Interest expense		(1,764)	(1,333)
Other income (expense), net		1,035	9
Change in fair value of earn-out liability		48,910	0
Loss on debt extinguishment		(492)	0
Total other income (expense)		47,695	(1,257)
Income before income taxes		15,798	14,562
Income tax expense		0	351
Net income and comprehensive income	[1]	15,798	14,211
Income allocable to participating securities		0	(14,045)
Net income attributable to common shareholders		$ 15,798	$ 166
Net income per share attributable to common shareholders:
Basic		$ 1.05	$ 0.12
Diluted		$ 0.44	$ 0.11
Weighted-average common shares outstanding:
Basic		15,105,851	1,410,549
Diluted		36,004,063	2,654,849
[1]	Historical shares and capital amounts have been retroactively restated for the reverse recapitalization as described in Note 1.

Statements of Convertible Prefe

Statements of Convertible Preferred Stock and Stockholders' Deficit - USD ($) $ in Thousands		Total	Series A Convertible Preferred Stock [Member]		Series B Convertible Preferred Stock [Member]		Series C Convertible Preferred Stock [Member]		Common Stock		Additional Paid-in Capital	Accumulated Deficit
Beginning Balance at Dec. 31, 2019	[1]		$ 46,567		$ 51,084		$ 35,573
Beginning Balance (shares) at Dec. 31, 2019	[1]		11,563,819		10,154,819		6,734,590
Beginning Balance at Dec. 31, 2019	[1]	$ (147,063)							$ 0		$ 3,847	$ (150,910)
Beginning Balance (shares) at Dec. 31, 2019	[1]								1,333,711
Stock option exercises, net (Shares)		111,354
Issuance of common stock	[1]	$ 108									108
Issuance of common stock (shares)	[1]								111,354
Stock-based compensation expense	[1]	499									499
Net income (loss)	[1]	14,211										14,211
Ending Balance at Dec. 31, 2020	[1]		$ 46,567		$ 51,084		$ 35,573
Ending Balance (shares) at Dec. 31, 2020	[1]		11,563,819		10,154,819		6,734,590
Ending Balance at Dec. 31, 2020	[1]	$ (132,245)							$ 0		4,454	(136,699)
Ending Balance (shares) at Dec. 31, 2020		1,445,065							1,445,065	[1]
Recapitalization transaction, net of transaction costs (refer to Note 3)	[1]	$ 51,974							$ 1		51,973
Recapitalization transaction, net of transaction costs (refer to Note 3), Share	[1]								10,347,611
Conversion of preferred stock into common stock upon completion of the Business Combination (refer to Note 3)	[1]	133,224	$ (46,567)		$ (51,084)		$ (35,573)		$ 3		133,221
Conversion of preferred stock into common stock upon completion of the Business Combination (refer to Note 3) (shares)	[1]		(11,563,819)		(10,154,819)		(6,734,590)		28,453,228
Contingently issuable Earn-Out Shares (refer to Note 10)	[1]	(61,040)									(61,040)
Stock option exercises, net	[1]	$ 56									56
Stock option exercises, net (Shares)		98,936							93,542	[1]
Cashless exercise of warrants, share	[1]								50,529
Cashless exercise of warrants	[1]	$ 857									857
Stock-based compensation expense	[1]	8,660									8,660
Net income (loss)	[1]	$ 15,798										15,798
Ending Balance at Dec. 31, 2021	[1]		$ 0		$ 0		$ 0
Ending Balance (shares) at Dec. 31, 2021		28,453,228	0	[1]	0	[1]	0	[1]
Ending Balance at Dec. 31, 2021	[1]	$ 17,284							$ 4		$ 138,181	$ (120,901)
Ending Balance (shares) at Dec. 31, 2021		40,389,975							40,389,975	[1]
[1]	Historical shares and capital amounts have been retroactively restated for the reverse recapitalization as described in Note 1.

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2021	Dec. 31, 2020
Operating activities:
Net income	[1]	$ 15,798	$ 14,211
Adjustments to reconcile net income to cash (used in) provided by operating activities:
Depreciation and amortization expense		24	160
Stock-based compensation		8,660	499
Gain on disposal of assets		0	(324)
Loss on debt extinguishment		492	0
Gain on change in fair value of warrant liability		(1,031)	(9)
Gain on change in fair value of earn-out liability		(48,910)	0
Non-cash interest expense		317	122
Changes in operating assets and liabilities:
Prepaid expenses and other current assets		(1,270)	90
Other non-current assets		(903)	0
Accounts payable		155	(251)
Accrued expenses		1,791	(665)
Operating lease right-of-use assets and liabilities, net		(11)	2
Net cash (used in) provided by operating activities		(24,888)	13,835
Investing activities:
Proceeds from sale of fixed assets		607	0
Purchases of fixed assets		(42)	(154)
Net cash (used in) provided by investing activities		565	(154)
Financing activities:
Proceeds from exercise of common stock options, net		56	108
Issuance of term loans, net of issuance costs		19,835	0
Repayment of term loans		(13,940)	(2,000)
Proceeds from Business Combination, net of offering costs paid (see Note 3)		52,858	0
Net cash provided by (used in) financing activities		58,809	(1,892)
Net increase in cash and cash equivalents		34,486	11,789
Cash and cash equivalents at beginning of period		15,216	3,427
Cash and cash equivalents at end of period		49,702	15,216
Supplemental disclosure of cash flow information:
Interest paid		1,340	975
Sales of property and equipment recorded as a receivable		0	607
Operating lease liabilities arising from obtaining right-of-use assets		179	375
Supplemental disclosure of non-cash investing and financing activities:
Conversion of preferred stock into common stock		133,224	0
Cashless warrant exercise		857	0
Purchases of fixed assets included in accounts payable and accrued expenses		$ 38	$ 0
[1]	Historical shares and capital amounts have been retroactively restated for the reverse recapitalization as described in Note 1.

Organization and Basis of Prese

Organization and Basis of Presentation	12 Months Ended
	Dec. 31, 2021
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Organization and Basis of Presentation	1. Organization and Basis of Presentation Description of Business Locust Walk Acquisition Corp. (“LWAC”) was initially formed on October 2, 2020 as a Delaware corporation formed for the purpose of effecting a m e On May 26, 2021, LWAC entered into an Agreement and Plan of Merger (the “Merger Agreement”) with Locust Walk Merger Sub, Inc., a Delaware corporation and a wholly owned subsidiary of LWAC (“Merger Sub”), and eFFECTOR Therapeutics, Inc., a Delaware corporation (“Old eFFECTOR”). Pursuant to the terms of the Merger Agreement, a business combination between LWAC and Old eFFECTOR was effected through the merger of the Merger Sub with and into Old eFFECTOR, with Old eFFECTOR surviving as the surviving company and a wholly-owned subsidiary of LWAC with the name of eFFECTOR Therapeutics Operations, Inc. On August 25, 2021, and in connection with the closing of the business combination (the “Business Combination”), LWAC was renamed eFFECTOR Therapeutics, Inc. (“eFFECTOR” or the “Company”). All outstanding preferred shares of Old eFFECTOR converted into common shares of Old eFFECTOR on a 1:1 basis, which were then converted, along with all outstanding common shares of Old eFFECTOR, into common shares of the surviving eFFECTOR company through application of an exchange ratio of approximately 0.09657 (the “Exchange Ratio”). The Company is a clinical-stage biopharmaceutical company focused on pioneering the discovery and development of a new class of oncology drugs the Company refers to as selective translation regulator inhibitors. The Company’s principal operations are in the United States, with its headquarters in Solana Beach, California. The Company has devoted substantially all of its resources to raising capital, identifying potential product candidates, establishing its intellectual property portfolio, conducting preclinical studies and clinical trials, establishing arrangements with third parties for the manufacture of its product candidates and related raw materials, and providing general and administrative support for these operations. The Company has not generated revenues from its principal operations through December 31, 2021. Basis of Presentation The Company’s consolidated financial statements are prepared in accordance with U.S. generally accepted accounting principles (“GAAP”). All intercompany balances and transactions have been eliminated in consolidation. The Business Combination was accounted for as a reverse recapitalization in accordance with U.S. GAAP. Under this method of accounting, LWAC was treated as the “acquired” Company and eFFECTOR is treated as the acquirer for financial reporting purposes. Accordingly, for accounting purposes, the Business Combination was treated as the equivalent of Old eFFECTOR issuing stock for the net assets of LWAC, accompanied by a recapitalization. The net assets of LWAC are stated at historical cost, with no goodwill or other intangible assets recorded. Old eFFECTOR was determined to be the accounting acquirer based on the following predominant factors: • Old eFFECTOR’s shareholders have a majority of the voting power of the combined company; • the Board and Management are primarily composed of individuals associated with Old eFFECTOR; and • Old eFFECTOR comprises all of the ongoing operations of the combined company. The consolidated assets, liabilities and results of operations prior to the Business Combination are those of Old eFFECTOR. The shares and corresponding capital amounts, options and related per share amounts, and income or losses per share, prior to the Business Combination, have been retroactively restated based on shares reflecting the Exchange Ratio established in the Business Combination. Liquidity The Company has a limited operating history and the sales and income potential of the Company’s business and market are unproven. The accompanying consolidated financial statements have been prepared assuming the Company will continue as a going concern, which contemplates the realization of assets and the satisfaction of liabilities in the normal course of business, and do not include any adjustments to reflect the possible future effects on the recoverability and classification of assets or amounts and classification of liabilities that may result from the outcome of this uncertainty. Management is required to perform a two-step The Company has experienced net losses and negative cash flows from operating activities since its inception, aside from the years ended December 31, 2021 and December 31, 2020 when net income was realized as a result of a gain in fair value recognized associated with the earn-out liability and non-recurring revenue in connection with the Research Collaboration and License Agreement with Pfizer, respectively. The Company has an accumulated deficit of $120.9 million at December 31, 2021. For the year ended December 31, 2021, the Company used $24.9 million in cash for operations. At December 31, 2021, the Company had cash and cash equivalents of $49.7 million. Management anticipates that its expenses will increase significantly in connection with its ongoing activities to support its research and development efforts, and it expects to incur substantial operating losses and negative cash flows from operations for the foreseeable future. The Company believes that its $49.7 million of cash and cash equivalents held as of December 31, 2021 are sufficient to fund planned operations for at least twelve months from the date these consolidated financial statements are issued. Additionally, in January 2022, the Company entered into an equity purchase agreement with Lincoln Park Capital Fund, LLC thirty-six Management’s expectations with respect to its ability to fund current planned operations is based on estimates that are subject to risks and uncertainties. Its operating plan may change as a result of many factors currently unknown to management and there can be no assurance that the current operating plan will be achieved in the time frame anticipated by the Company, and it may need to seek additional funds sooner than anticipated. If adequate funds are not available to the Company on a timely basis, management may be required to delay, limit, reduce or terminate certain of its research, product development or future commercialization efforts, obtain funds through arrangements with collaborators on terms unfavorable to the Company, or pursue merger or acquisition strategies, all of which could adversely affect the holdings or the rights of its stockholders.

Summary of Significant Accounti

Summary of Significant Accounting Policies	12 Months Ended
	Dec. 31, 2021
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	2. Summary of Significant Accounting Policies Use of Estimates The Company’s consolidated financial statements are prepared in accordance with accounting principles generally accepted in the United States (“GAAP”). The preparation of the Company’s consolidated financial statements requires it to make estimates and assumptions that impact the reported amounts of assets, liabilities and expenses and the disclosure of contingent liabilities in the Company’s consolidated financial statements and accompanying notes. The most significant estimate in the Company’s consolidated financial statements relates to its clinical trial expense accruals. Management evaluates its estimates on an ongoing basis. Although these estimates are based on the Company’s historical experience, knowledge of current events and actions it may undertake in the future, actual results may ultimately materially differ from these estimates and assumptions. Cash and Cash Equivalents The Company considers all highly liquid investments with an original maturity of three months or less at the date of purchase to be cash equivalents. Cash equivalents primarily represent funds invested in readily available operating and money market funds. Fair Value of Financial Instruments The carrying amounts of all cash equivalents, prepaid expenses and other assets, accounts payable and accrued liabilities are reasonable estimates of their fair value because of the short-term nature of these items. Based on the borrowing rates currently available to the Company for loans with similar terms, the Company believes the fair value of the term loans approximate their carrying value (see Note 7). Concentration of Credit Risk and Other Risks and Uncertainties Financial instruments, which potentially subject the Company to significant concentration of credit risk, consist primarily of cash and cash equivalents. The Company maintains deposits in a federally insured major financial institution in excess of federally insured limits. The Company has not experienced any losses in such accounts and management believes that the Company is not exposed to significant credit risk due to the financial position of the depository institution in which those deposits are held. The Company is subject to a number of risks similar to other biopharmaceutical companies, including, but not limited to, the need to obtain adequate additional funding, possible failure of current or future preclinical studies or clinical trials, reliance on third parties or partners to conduct its clinical trials, the need to obtain regulatory and marketing approvals for its drug candidates or to rely on partners to do so, competitors developing new technological innovations, the need to successfully commercialize and gain market acceptance of its drug candidates, the right to develop and commercialize drug candidates pursuant to the terms and conditions of the licenses granted to the Company, protection of proprietary technology, the ability to make milestone, royalty or other payments due under any license or collaboration agreements, and the need to secure and maintain adequate manufacturing arrangements with third parties. If the Company does not successfully commercialize or partner any of its drug candidates, it will be unable to generate product revenue or achieve profitability. Property and Equipment Property and equipment are recorded at cost and depreciated or amortized using the straight-line method over the estimated useful lives of the assets (generally three Long-Lived Assets The Company regularly reviews the carrying value and estimated lives of all of its long-lived assets, including property and equipment to determine whether indicators of impairment may exist which warrant adjustments to carrying values or estimated useful lives. Should an impairment exist, the impairment loss would be measured based on the excess over the carrying amount of the asset’s fair value. The Company has not recognized any impairment losses from inception through December 31, 2021. Leases At the inception of a contractual arrangement, the Company determines whether the contract contains a lease by assessing whether there is an identified asset and whether the contract conveys the right to control the use of the identified asset in exchange for consideration over a period of time. If both criteria are met, the Company records the associated lease liability and corresponding right-of-use right-of-use right-of-use non-lease Grant Revenue The Company’s grant revenues are derived from a grant with the Defense Advanced Research Projects Agency (“DARPA”) through the University of California, San Francisco (“UCSF”). The Company recognizes DARPA Grant revenue as reimbursable grant costs are incurred up to pre-approved Research and Development Costs Research and development expenses primarily consist of costs associated with the preclinical and clinical development of the Company’s product candidates. Research and development costs are expensed as incurred. Clinical Trial Accruals and Preclinical Studies The Company is required to estimate expenses resulting from our obligations under contracts with vendors and consultants, CROs and clinical sites in connection with conducting clinical trials and preclinical studies. The financial terms of these contracts are subject to negotiations which vary from contract to contract and may result in payment flows that do not match the periods over which materials or services are provided under such contracts. The Company reflects clinical trial and preclinical study expenses in the consolidated financial statements by matching those expenses with the period in which services and efforts are expended. The Company accounts for these expenses according to the progress of the clinical trial or preclinical study as measured by the timing of various aspects of the clinical trial, preclinical study, or related activities. The Company determines accrual estimates through review of the underlying contracts along with preparation of financial models taking into account correspondence with clinical and other key personnel and third-party service providers as to the progress of the clinical trials, preclinical studies, or other services being conducted. During the course of a clinical trial or preclinical study, the Company adjusts the rate of expense recognition if actual results differ from estimates. Patent Costs Costs related to filing and pursuing patent applications are recorded as general and administrative expense and expensed as incurred since recoverability of such expenditures is uncertain. Revenue Recognition The Company evaluates collaboration arrangements to determine whether units of account within the collaboration arrangement exhibit the characteristics of a vendor and customer relationship. For arrangements and units of account where a customer relationship exists, the Company applies the revenue recognition guidance. The Company recognizes revenue upon the transfer of promised goods or services to customers in an amount that reflects the consideration to which the Company expects to be entitled in exchange for those goods or services. To determine revenue recognition for contracts with customers the Company performs the following five steps: (i) identify the contract(s) with a customer; (ii) identify the performance obligations in the contract; (iii) determine the transaction price; (iv) allocate the transaction price to the performance obligations in the contract; and (v) recognize revenue when (or as) the Company satisfies the performance obligations. At contract inception, the Company assesses the goods or services promised within each contract and assesses whether each promised good or service is distinct and determines those that are performance obligations. The Company then recognizes as revenue the amount of the transaction price that is allocated to the respective performance obligation when (or as) the performance obligation is satisfied. If a license to the Company’s intellectual property is determined to be distinct from the other performance obligations identified in the arrangement, the Company recognizes revenues from non-refundable, For research and development services performed under a collaboration agreement in which the performance obligation is satisfied over time, the Company measures the progress of the activities using an input method. The input methods used are based on the effort expended or costs incurred toward the satisfaction of the related performance obligation. The Company estimates the amount of effort expended, including the time the Company estimates it will take to complete the activities, or costs incurred in a given period, relative to the estimated total effort or costs to satisfy the performance obligation. This results in a percentage that is multiplied by the consideration allocated to the research and development services to determine the amount of revenue recognized each period. This approach requires estimates and the use of significant judgement. If the estimates or judgements change over the course of the collaboration, they may affect the timing and amount of revenue recognized in the current and future periods. Milestones At the inception of each arrangement that includes milestone payments (variable consideration), the Company evaluates whether the milestones are considered probable of being reached and estimates the amount to be included in the transaction price using the most likely amount method. If it is probable that a significant revenue reversal would not occur, the re-evaluates catch-up Royalties For arrangements that include sales-based royalties, including milestone payments based on the level of sales, and for which the license is deemed to be the predominant item to which the royalties relate, the Company recognizes revenue at the later of (i) when the related sales occur, or (ii) when the performance obligation to which some or all of the royalty has been allocated has been satisfied (or partially satisfied). To date, the Company has not recognized any royalty revenue from any collaborative arrangement. Income Taxes The Company accounts for income taxes under the asset and liability method, which requires the recognition of deferred tax assets and liabilities for the expected future tax consequences of events that have been included in the consolidated financial statements. Under this method, deferred tax assets and liabilities are determined on the basis of the differences between the consolidated financial statements and tax basis of assets and liabilities using enacted tax rates in effect for the year in which the differences are expected to reverse. The effect of a change in tax rates on deferred tax assets and liabilities is recognized in income in the period that includes the enactment date. The Company recognizes deferred tax assets to the extent that the Company believes these assets are more likely than not to be realized. In making such a determination, management considers all available positive and negative evidence, including future reversals of existing taxable temporary differences, projected future taxable income, tax-planning As of December 31, 2021 and 2020, the Company maintained valuation allowances against its deferred tax assets as the Company concluded it had not met the “more likely than not” to be realized threshold. Changes in the valuation allowance when they are recognized in the provision for income taxes may result in a change in the estimated annual effective tax rate. The Company records uncertain tax positions on the basis of a two-step Comprehensive Income Net income and comprehensive income were the same for all periods presented; therefore, a separate statement of comprehensive income is not included in the accompanying consolidated financial statements. Segment Reporting Operating segments are identified as components of an enterprise about which separate discrete financial information is available for evaluation by the chief operating decision-maker in making decisions regarding resource allocation and assessing performance. The Company and its chief operating decision-maker view the Company’s operations and manage its business in one operating segment. Stock-Based Compensation Expense Stock-based compensation expense represents the cost of the grant date fair value of employee stock option grants recognized over the requisite service period of the awards (usually the vesting period) on a straight- line basis. The Company estimates the fair value of stock option grants using the Black-Scholes option-pricing model. The Company accounts for stock options granted to non-employees The Black-Scholes option-pricing model requires the use of subjective assumptions, including the risk-free interest rate, the expected stock price volatility, the expected term of stock options, and the expected dividend yield. The fair value of the underlying common stock used within the Black-Scholes option-pricing model is based on the closing price of common stock on the date of grant. Preferred Stock Warrants The Company had previously issued freestanding warrants to purchase shares of its convertible preferred stock. Since the underlying convertible preferred stock was classified outside of permanent equity, these warrants were classified as liabilities in the accompanying consolidated balance sheets. Warrants classified as liabilities are recorded at their estimated fair value on the date of issuance and are revalued at each subsequent balance sheet date, with fair value changes recognized in other income (expense), net in the accompanying consolidated statements of operations and comprehensive income. The Company estimates the fair value of these warrants using the Black-Scholes option pricing model. Public and Private Placement Warrants Upon completion of the Business Combination, the Company assumed public and private placement warrants that were issued by LWAC in connection with their IPO in January 2021 whereby holders of the public and private placement warrants are entitled to acquire common stock of the Company. The Company has concluded that the public warrants are equity-classified. Since the settlement value of the private placement warrants is dependent, in part, on who holds the warrants at the time of settlement, they are not considered indexed to the Company’s stock and are therefore recorded as liabilities. Warrants classified as liabilities are recorded at their estimated fair value on the date of issuance and are revalued at each subsequent balance sheet date, with fair value changes recognized in other income (expense), net in the accompanying consolidated statements of operations and comprehensive income. The Company estimates the fair value of these warrants using the Black-Scholes option pricing model. Earn-out In accordance with the Merger Agreement, 5,000,000 shares are contingently issuable to Old eFFECTOR stockholders and option holders upon the occurrence of the Triggering Event (see Note 3), defined within the Merger Agreement as the date on which the common stock price equals or exceeds $20.00 over at least 20 trading days out of 30 consecutive trading day period for the two-year period Earn-Out Shares the earn-out period The Company has determined that the contingent obligation to issue Earn-Out Shares 815-40 the Earn-Out Shares The Company has determined that the contingent obligation to issue Earn-Out Shares holder Earn-Out Shares Recent Accounting Pronouncements From time to time, new accounting pronouncements are issued by the Financial Accounting Standards Board (“FASB”) or other standard setting bodies and adopted by the Company as of the specified effective date. Unless otherwise discussed, the Company believes, based on their preliminary assessment, that the impact of recently issued standards that are not yet effective will not have a material impact on their financial position or results of operations upon adoption. In August 2020, the FASB issued ASU 2020-06, Debt-Debt with Conversion and Other Options (Subtopic 470-20) 815-40) Net Income Per Share The Company computes net income per share in accordance with the FASB guidance for Earnings Per Share, which established standards regarding the computation of earnings per share by companies that have issued securities other than common stock that contractually entitle the holder to participate in earnings and dividends. The guidance requires earnings available to common shareholders for the period, after deduction of preferred stock preferences, to be allocated between the common and preferred shareholders based on their respective rights to receive dividends. The Company is not required to present basic and diluted net income per share for securities other than common stock; therefore, the net income per share amounts only pertain to the Company’s common stock. Basic net if-converted two-class The Company has used the treasury stock method to calculate diluted net income per share for the year ended December 31, 2021, as there are no participating securities as of December 31, 2021 (and were no participating securities in the period of net income during 2021). The Company used the two-class method for the year ended December 31, 2020, as the if-converted method was anti-dilutive. Diluted net income per share for the years ended December 31, 2021 and 2020 also reflects the assumed exercise of options outstanding during the period using the treasury stock method, to the extent dilutive. Warrants were included in the calculation of diluted net income per share for the years ended December 31, 2021 and 2020 to the extent the warrants were dilutive. As a result of the Business Combination, the Company has retroactively restated the weighted average shares outstanding prior to August 25, 2021, to give effect to the Exchange Ratio. The following table sets forth the computation of bas ic and diluted net income per share (in thousands, except share and per share data): For the Year Ended 2021 2020 Basic Net Income per share Net income $ 15,798 $ 14,211 Less: income allocated to participating securities — (14,045 ) Net income attributable to common shareholders $ 15,798 $ 166 Weighted average common shares outstanding - basic 15,105,851 1,410,549 Net income per share - basic $ 1.05 $ 0.12 Diluted Net Income per share Net income $ 15,798 $ 14,211 Less: income allocated to participating securities — (13,912 ) Net income attributable to common shareholders $ 15,798 $ 299 Weighted average common shares outstanding - basic 15,105,851 1,410,549 Weighted average effect of dilutive securities: Convertible preferred stock 18,556,453 — Stock options 2,341,759 1,244,300 Weighted average common shares outstanding - diluted 36,004,063 2,654,849 Net income per share - diluted $ 0.44 $ 0.11 Potentially dilutive securities as of December 31, 2021 and 2020 are as follows (in common stock equivalent shares): For the Year Ended 2021 2020 Series A Convertible Preferred Stock — 11,563,819 Series B Convertible Preferred Stock — 10,154,819 Series C Convertible Preferred Stock — 6,734,590 Series C Convertible Preferred Stock Warrants — 70,455 Public warrants 5,833,333 — Private placement warrants 181,667 — Earn-Out 5,000,000 — Unvested sponsor shares 300,000 — Stock options outstanding 403,278 770,150 Total 11,718,278 29,293,833

Business Combination

Business Combination	12 Months Ended
	Dec. 31, 2021
Business Combinations [Abstract]
Business Combination	3. Business Combination As discussed in Note 1, on August 25, 2021, the Company completed the Business Combination pursuant to the Merger Agreement. Upon closing of the Business Combination, the combined company was renamed eFFECTOR Therapeutics, Inc. As a result of the Business Combination, each share of Old eFFECTOR preferred stock and common stock was converted into the right to receive approximately 0.09657 shares of the Company’s common stock (the “Common Stock”) for an aggregate of 30,021,762 shares of common stock issued in the Business Combination. Former holders of shares of Old eFFECTOR common stock (including shares received as a result of the conversion of Old eFFECTOR preferred stock and the exercise of Old eFFECTOR warrants) and former holders of options to purchase shares of Old eFFECTOR will also be entitled to receive their pro rata share of up to 5,000,000 earn-out shares “Earn-Out a 30-day trading Earn-Out a per-share price Pursuant to subscription agreements entered into in connection with the Merger Agreement (collectively, the “Subscription Agreements”), certain investors agreed to subscribe for an aggregate of 6,070,003 newly-issued shares of Common Stock at a purchase price of $10.00 per share for an aggregate purchase price of $60.7 million (the “PIPE Financing”). At the closing, we consummated the PIPE Financing. A total of 10,347,611 shares of common stock were issued in connection with the close of the Business Combination, inclusive of the PIPE Financing shares and shares held by LWAC sponsor and public investors. In connection with the closing of the Business Combination, the LWAC sponsor received 4,056,250 shares of eFFECTOR common stock, of which 300,000 shares were subject to vesting if, on or prior to August 25, 2024, the price of shares of common stock equals or exceeds $15.00 per share for a period of at least 20 trading days out of 30 consecutive trading days ending on the trading day immediately prior to the date of determination (the “Sponsor Shares”). The 300,000 sponsor shares subject to vesting meet the criteria for equity classification, but are not considered outstanding from an accounting perspective. These shares are considered issued but not outstanding as of December 31, 2021 and have been excluded from outstanding shares in the calculation of net income per share for the year ended December 31, 2021. After giving effect to the Business Combination, and the consummation of the PIPE Financing, there were 40,669,373 shares of Common Stock issued and 40,369,373 shares of Common Stock issued and outstanding. In connection with the closing of the Business Combination, options to purchase shares of Old eFFECTOR common stock were converted, at an exchange ratio of approximately 0.09657, into options to purchase an aggregate of 3,920,657 shares of Common Stock, with a weighted-average exercise price of $1.56 per share. Pursuant to the terms of the Merger Agreement, the Company’s shareholders exchanged their interests in the Company for shares of common stock of eFFECTOR. In addition, awards under the Company’s existing equity incentive plans, including the 2013 Plan, continue in full force and effect on the same terms and conditions as were previously applicable to such awards, subject to adjustments to the exercise price and number of shares of common stock issuable upon exercise based on the final exchange ratio of approximately 0.09657. Gross proceeds from this transaction totaled approximately $67.0 million, which included funds held in LWAC’s trust and operating accounts and the completion of a concurrent sale of 6,070,003 shares of Common Stock at a purchase price of $10.00 per share in the PIPE Financing. The transaction was accounted for as a “reverse recapitalization” in accordance with US GAAP. Under the reverse recapitalization model, the Business Combination was treated as eFFECTOR issuing equity for the net assets of LWAC, with no goodwill or intangible assets recorded. Under this method of accounting, LWAC was treated as the “acquired” company for financial reporting purposes. This determination is primarily based on the fact that subsequent to the Business Combination, eFFECTOR stockholders have a majority of the Board of the combined company, comprise all of the ongoing operations of the combined entity, comprise a majority of the governing body of the combined company, and eFFECTOR management comprises all of the senior management of the combined company. All periods prior to the Business Combination have been retroactively adjusted using the Exchange Ratio for the equivalent number of shares outstanding immediately after the Business Combination to effect the reverse recapitalization. In connection with the Business Combination, the Company raised $52.9 million of net proceeds. This amount was comprised of $6.3 million of cash held in LWAC’s trust and operating accounts from its initial public offering and $60.7 million of cash in connection with the PIPE Financing, less LWAC’s transaction costs and underwriters’ fees of $11.1 million. Old eFFECTOR also incurred $3.0 million of transaction costs, consisting of banking, legal, and other professional fees which were recorded as a reduction to additional paid-in The Company assessed the instruments issued in the Business Combination to determine the allocation of transaction costs between additional paid-in-capital and expense with an immaterial amount being allocated to expense. The following summarizes the common stock outstanding following the consummation of the Business Combination, PIPE Financing and the automatic cashless exercise of Old eFFECTOR warrants: Shares % Old eFFECTOR Stockholders 30,021,762 74.4 % LWAC Stockholders 521,358 1.3 % LWAC Founders (1) 3,756,250 9.3 % PIPE Investors 6,070,003 15.0 % Total 40,369,373 100.0 % (1) Excludes 300,000 Sponsor Shares subject to vesting that are not considered outstanding from an accounting perspective.

Fair Value Measurements

Fair Value Measurements	12 Months Ended
	Dec. 31, 2021
Fair Value Disclosures [Abstract]
Fair Value Measurements	4. Fair Value Measurements The accounting guidance defines fair value, establishes a consistent framework for measuring fair value and expands disclosure for each major asset and liability category measured at fair value on either a recurring or nonrecurring basis. Fair value is defined as an exit price, representing the amount that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants. As such, fair value is a market-based measurement that should be determined based on assumptions that market participants would use in pricing an asset or liability. As a basis for considering such assumptions, the accounting guidance establishes a three-tier fair value hierarchy, which prioritizes the inputs used in measuring fair value as follows: Level 1: Unadjusted quoted prices in active markets that are accessible at the measurement date for identical, unrestricted assets or liabilities. Level 2: Quoted prices for similar assets and liabilities in active markets, quoted prices in markets that are not active, or inputs which are observable, either directly or indirectly, for substantially the full term of the asset or liability. Level 3: Prices or valuation techniques that require inputs that are both significant to the fair value measurement and unobservable (i.e. supported by little or no market activity). The Company’s cash equivalents are classified using Level 1 inputs within the fair value hierarchy because they are valued using quoted market prices, broker or dealer quotations, or alternative pricing sources with reasonable levels of price transparency. None of the Company’s non-financial non-recurring presented. The Company estimates the fair value of preferred stock warrants at the time of issuance and subsequent remeasurement using the Black-Scholes option pricing model at each reporting date, if required, based on the following inputs: the risk-free interest rates; the expected dividend rates; the remaining contractual life of the warrants; the fair value of the underlying stock; and the expected volatility of the price of the underlying stock. The estimates are based, in part, on subjective assumptions and could differ materially in the future. Changes to these assumptions as well as the fair value of the Company’s stock on the reporting date can have a significant impact on the fair value of the warrant liability. The following table summarizes the Company’s assets and liabilities that require fair value measurements on a recurring basis and their respective input levels based on the fair value hierarchy as of December 31, 2021 and December 31, 2020 (in thousands): Fair Value Measurements Using December 31, Quoted Prices Significant Significant Assets Money market funds $ 49,702 $ 49,702 $ — $ — Total assets $ 49,702 $ 49,702 $ — $ — Liabilities Private placement warrant liability $ 678 $ — $ — $ 678 Earn-out 12,130 — — 12,130 Total liabilities $ 12,808 $ — $ — $ 12,808 Fair Value Measurements Using December 31, Quoted Prices Significant Significant Assets Money market funds $ 15,216 $ 15,216 $ — $ — Total assets $ 15,216 $ 15,216 $ — $ — Liabilities Preferred stock warrant liability $ 433 $ — $ — $ 433 Total liabilities $ 433 $ — $ — $ 433 The preferred stock warranty liability was measured at fair value, using a combination of observable and unobservable inputs. The change in fair value of the preferred stock warrant liability is recorded in Other income (expense), net, on the consolidated statements of operations and comprehensive income. All outstanding preferred stock warrants were cashless exercised as a result of the Business Combination on August 25, 2021 (See Note 8). The preferred stock warrants were remeasured to fair value on the date of cashless exercise based on the net shares issued and fair value of common stock on the settlement date, which was the close date of the Business Combination on August 25, 2021. The following key assumptions were used in determining the fair value of the preferred stock warrant liability valued using the Black-Scholes option pricing model as of December 31, 2020: December 31, 2020 Fair value of Series C convertible preferred stock $ 0.70 Expected volatility 96.3 % Risk-free interest rate 0.7 % Expected term (in years) 7.7 Expected dividend yield — The following table presents activity for the preferred stock warrant liability measured at fair value using significant unobservable Level 3 inputs during the years ended December 31, 2021 and 2020 (in thousands): Series C Preferred Stock Balance at December 31, 2019 $ 442 Change in fair value (9 ) Balance at December 31, 2020 $ 433 Issuance of new warrants 271 Change in fair value 153 Warrant exercises (857 ) Balance at December 31, 2021 $ — In connection with the Business Combination, the Company assumed the public and private placement warrants described in Note 8. The private placement warrants are precluded from equity treatment and are recorded as liabilities as they are not considered indexed to the Company’s Common Stock. The private placement warrant liability is measured at fair value, using a combination of observable and unobservable inputs. The change in fair value of the private placement warrant liability is recorded in Other income (expense) on the consolidated statements of operations and comprehensive income. The following key assumptions were used in determining the fair value of the private placement warrant liability valued using the Black-Scholes option pricing model as of December 31, 2021 and August 25, 2021: December 31, 2021 As of August 25, 2021 at Initial Measurement Common stock price $ 8.28 $ 16.98 Expected volatility 65.0 % 60.0 % Risk-free interest rate 1.3 % 0.8 % Expected term (in years) 4.7 5.0 Expected dividend yield — — The following table presents activity for the private placement warrant liability measured at fair value using significant unobservable Level 3 inputs during the year ended December 31, 2021 (in thousands): Private Placement Warrant Liability Private Placement Warrants liability - August 25, 2021 (closing date) $ 1,862 Change in fair value - Closing Date through December 31, 2021 (1,184 ) Private Placement Warrants liability at December 31, 2021 $ 678 Former holders of shares of Old eFFECTOR common stock were allocated Earn-Out Earn-Out

Property and Equipment, net

Property and Equipment, net	12 Months Ended
	Dec. 31, 2021
Property, Plant and Equipment [Abstract]
Property and Equipment, net	5. Property and Equipment, net Property and equipment, net consists of the following (in thousands): December 31, December 31, 2021 2020 Lab equipment $ 30 $ 30 Computer and office equipment 127 133 Furniture and fixtures 64 64 Construction in process 74 — 295 227 Less accumulated depreciation and amortization (204 ) (193 ) $ 91 $ 34 The Company recorded depreciation and amortization expense of $24,000 and $0.2 million for the years ended December 31, 2021 and 2020, respectively.

Accrued Expenses

Accrued Expenses	12 Months Ended
	Dec. 31, 2021
Payables and Accruals [Abstract]
Accrued Expenses	6. Accrued Expenses Accrued expenses consist of the following (in thousands): December 31, December 31, 2021 2020 Employee compensation $ 1,343 $ 230 Research and development 1,115 755 Professional and outside services 452 44 Interest 133 598 Income taxes payable 351 351 Other 24 6 $ 3,418 $ 1,984

Term Loans

Term Loans	12 Months Ended
	Dec. 31, 2021
Debt Disclosure [Abstract]
Term Loans	7. Term Loans SVB Term Loans In August 2018, Old eFFECTOR entered into a Loan and Security Agreement (“LSA”) with Silicon Valley Bank (“SVB”), pursuant to which the Company may borrow up to $20.0 million, issuable in three separate tranches of $7.5 million (“Term Loan A”), $7.5 million (“Term Loan B”) and $5.0 million (“Term Loan C”), collectively referred to as the Term Loans. Term Loan A became available to the Company at the effective date of the LSA on August 31, 2018 and the Company borrowed the $7.5 million under the Term Loan A on that date, receiving the cash proceeds on September 5, 2018. Term Loan B was immediately available commencing on the effective date of the LSA and ending on the earlier of 1) August 31, 2019, or 2) the occurrence of an event of default. The Company borrowed the $7.5 million under Term Loan B on November 19, 2018. Term Loan C was not drawn. The Term Loans had an interest-only period that commenced upon the borrowing of each tranche of the Term Loans with interest due and payable upon the first day of each month. The interest-only period ended August 31, 2020. The Company was required to make a final payment equal to 5.5% of the original aggregate principal amount of the Term Loans at maturity, which was accrued over the term of the debt arrangements. The Term Loans had a maturity date of February 1, 2023. In connection with the LSA, the Company issued two separate warrants, each to purchase up to 46,970 shares of Series C Preferred Stock at an exercise price of $5.33 per share, to SVB and Life Science Loans II, LLC (life science loan sector of SVB). The number of shares subject to each warrant as of December 31, 2020, was 35,227 in connection with the Term Loan A and Term Loan B . Each warrant was automatically exercised on a cashless basis on August 25, 2021, in connection with the completion of the Business Combination, for 16,477 shares of Common Stock. The Term Loans carried an interest rate equal to the greater of 1.5% plus prime or 6.5%, with an effective interest rate at December 31, 2020, of 9.1% and 9.0% for Term Loan A and Term Loan B, respectively. The Company recorded a debt discount of $0.2 million for the estimated fair value of warrants and debt issuance costs upon the borrowing of each Term Loan A and Term Loan B, which was being amortized to interest expense over the term of the loan using the effective-interest method. As of December 31, 2020, the Company had $13.0 million of outstanding principal under the Term Loans of which $12.9 million is reflected on the balance sheet net of debt discounts. Interest expense, including amortization of debt discount related to the SVB Term Loans, totaled $0.2 million and $1.3 million for the years ended December 31, 2021 and 2020, respectively. In March 2021, Old eFFECTOR repaid the SVB Term Loans using the proceeds from Oxford Term A Loans (defined below). The aggregate outstanding principal balance of SVB Term Loans A and B was $11.5 million at the date of repayment. The Company paid the entire outstanding principal balance, along with a final payment in the amount of $0.8 million (equal to 5.5% of the original aggregate principal amount), a prepayment fee of $0.1 million (equal to 1% of the original aggregate principal amount), and $37,000 of accrued interest. The Company recorded a loss on debt extinguishment in the amount of $0.5 million in connection with the transaction, which has been recorded in Loss on debt extinguishment on the Consolidated Statements of Operations and Comprehensive Income for the period. The loss on debt extinguishment includes the unamortized debt discount and final payment associated with Term Loan A and Term Loan B at the time of extinguishment along with the $0.1 million prepayment fee. Oxford Term Loans In March 2021, Old eFFECTOR entered into a Loan and Security Agreement (“Oxford LSA”) with Oxford Finance LLC (“Oxford”), pursuant to which the Company may borrow up to $30.0 million, issuable in two separate tranches of $20.0 million (“Term A Loans”) and $10.0 million (“Term B Loans”), collectively referred to as the Oxford Loans. The Term A Loans became available to the Company at the effective date of the Oxford LSA on March 19, 2021 and $12.5 million of the proceeds were used to pay off the outstanding SVB Term Loans. The remaining net proceeds from Term A Loans of $7.4 million, after taking into effect specified issuance and legal fees designated within the distribution letter, were distributed to the Company in March 2021. In accordance with the amendment to the Oxford LSA executed in February 2022 (see Note 17), Term B Loans will only become available to the Company after January 1, 2023, and upon achievement of certain clinical development milestones, until the earlier of (i) June 30, 2023, (ii) forty-five days after the occurrence of the Phase II Milestones, and (iii) the occurrence of an event of default. The Term A Loans have an interest-only period that commences upon the borrowing with interest due and payable upon the first day of each month. Prior to the execution of the amendment in February 2022, the interest-only period ended May 1, 2023, provided that upon the funding of the Term B Loans the end date would be extended to May 1, 2024. In accordance with the amendment to the Oxford LSA executed in February 2022 (see Note 17), the interest-only period will end March 1, 2024, provided that upon the funding of the Term B Loans the end date will be extended to March 1, 2025. The Company is required to make a final payment equal to 5.5% of each funded tranche at maturity, which has been recorded as a debt discount for the Term A Loan which is outstanding and is being amortized over the term of the debt arrangements. The Oxford Loans have a maturity date of February 1, 2027, after the execution of the amendment to the Oxford LSA in February 2022 (see Note 17). In connection with the Oxford LSA, the Company issued warrants to purchase a total of 37,575 shares of Series C Preferred Stock at an exercise price of $5.33 per share. The warrants were automatically exercised on a cashless basis on August 25, 2021, in connection with the completion of the Business Combination, for 17,575 shares of Common Stock. The Oxford Loans carry a variable interest rate equal to the greater of (i) 7.7% and (ii) the sum of the prime rate plus 4.45%. The Company has the option to prepay all, but not less than all, of the borrowed amounts, F-23 provided that the Company will be obligated to pay a prepayment fee equal to (i) 3.0% of the outstanding principal balance of the applicable Oxford Loans if prepayment is made prior to the first anniversary of the effective date of the Oxford LSA, (ii) 2.0% of the outstanding principal balance of the applicable Oxford Loans if prepayment is made after the first anniversary of the effective date of the Oxford LSA but before the second anniversary, and (iii) 1.0% of the outstanding principal balance of the applicable Oxford Loans if prepayment is made after the second anniversary of the effective date of the Oxford LSA but before the third anniversary. No prepayment fee will apply for a prepayment made after the third anniversary of the effective date of the Oxford LSA and prior to the maturity date. The Company’s obligations under the Oxford LSA are secured by a first priority security interest in substantially all of its current and future assets, other than its owned intellectual property. The Company is also obligated to comply with various other customary covenants, including restrictions on its ability to encumber intellectual property assets without consent. The Company recorded a debt discount of $1.5 million for the estimated fair value of warrants, debt issuance costs upon the borrowing of Term A Loans, and final payment to be made, which is being amortized to interest expense over the term of the loan using the effective-interest method. As of December 31, 2021, the Company had $20.0 million of outstanding principal under the Term A Loans of which $18.8 million is reflected on the balance sheet net of debt discounts. Interest expense, including amortization of debt discount related to the Oxford Term A Loans, totaled $1.5 million for the year ended December 31, 2021. The Company is in compliance with all covenants under the Oxford LSA as of December 31, 2021. The Term A Loans include customary events of default, including instances of a material adverse change in our operations, that may require prepayment of the outstanding Term A Loans. There have been no events of default as of the date of issuance of these consolidated financial statements. Based on the outstanding principal amounts for the Company’s Term A Loans, the following table sets forth by year the Company’s required future principal payments as of December 31, 2021 (in thousands): As of December 31, 2021 2023 $ 4,444 2024 6,667 2025 6,667 2026 2,222 Required future principal payments $ 20,000 Unamortized debt discount (1,240 ) Non-current $ 18,760

Warrants

Warrants	12 Months Ended
	Dec. 31, 2021
Warrants and Rights Note Disclosure [Abstract]
Warrants	8. Warrants Preferred Stock Warrants The Company accounts for its warrants to purchase shares of convertible preferred stock as a liability. The Company adjusted the liability for changes in fair value of these warrants up until the closing date of the Business Combination. Upon consummation of the Business Combination on August 25, 2021, the outstanding warrants were cashless exercised and 50,529 total net shares of common stock were issued, after giving effect to the application of the Exchange Ratio. F-24 The following table summarizes the outstanding warrants to purchase shares of preferred stock and the corresponding exercise price as of December 31, 2021 and December 31, 2020: December 31, December 31, Exercise Expiration Date Series C preferred stock warrants — 70,455 $ 5.33 August 31, 2028 Series C preferred stock warrants — — $ 5.33 March 19, 2031 Assumed Public Warrants and Private Placement Warrants Following the consummation of the Business Combination, holders of the public warrants and private placement warrants are entitled to acquire common stock of the Company. The warrants became exercisable on January 12, 2022, which is 12 months from the closing of the LWAC’s initial public offering. Each whole warrant entitles the registered holder to purchase one share of Common Stock at an exercise price of $11.50 per share. The public warrants and private placement warrants will expire five years after the completion of the Business Combination. Once the public warrants and private placement warrants became exercisable, the Company has the right to redeem the outstanding warrants in whole and not in part at a price of $0.01 per warrant upon a minimum of 30 days’ prior written notice of redemption, if and only if the last sale price of the Common Stock equals or exceeds $18.00 per share for any 20 trading days within a 30-trading The private placement warrants are identical to the public warrants except that, so long as they are held by the Sponsor or its permitted transferees: (i) they will not be redeemable by the Company; (ii) they may be exercised by the holders on a cashless basis; and (iii) they are subject to registration rights. Private placement warrants are liability-classified (See Note 4) and the public warrants are equity-classified. The following table summarizes the number of outstanding public warrants and private placement warrants and the corresponding exercise price as of December 31, 2021 and December 31, 2020: December 31, December 31, Exercise Expiration Date Public warrants 5,833,333 — $ 11.50 August 24, 2026 Private placement warrants 181,667 — $ 11.50 August 24, 2026

Convertible Preferred Stock and

Convertible Preferred Stock and Stockholders' Deficit	12 Months Ended
	Dec. 31, 2021
Redeemable Convertible Preferred Stock And Stockholders Equity [Abstract]
Convertible Preferred Stock and Stockholders' Deficit	9. Preferred Stock and Stockholders’ Equity (Deficit) Preferred Stock In April 2019, O In April 2019, prior to the completion of the Series C Closing, the existing Series C investors agreed to amend the Series C Preferred Stock Purchase Agreement (“Amendment”) to include a provision that automatically converts all classes of preferred shares held by a Series C investor who did not participate in the Series C Closing into common shares on a 10:1 2,493,021 916,629 258,805 non-participating 366,845 convertible preferred 15.5 Upon closing of the Business Combination transaction, pursuant to the terms of the Amended and Restated Certificate of Incorporation, the Company authorized 100,000,000 shares of preferred stock with a par value $0.0001 per share. eFFECTOR’s board of directors has the authority, without further action by the stockholders to issue such shares of preferred stock in one or more series, to establish from time to time the number of shares to be included in each such series, and to fix the dividend, voting, and other rights, preferences and privileges of the shares. There were no issued and outstanding shares of preferred stock as of December 31, 2021. In connection with the closing of the Business Combination on August 25, 2021, all Old eFFECTOR convertible preferred stock was converted into Common Stock of eFFECTOR at an Exchange Ratio of 0.09657. 28,453,228 total shares of Old eFFECTOR convertible preferred stock (as adjusted for the Exchange Ratio), composed of 11,563,819 shares of Old eFFECTOR Series A convertible preferred stock, 10,154,819 shares of Old eFFECTOR Series B convertible preferred stock, and 6,734,590 shares of Old eFFECTOR Series C convertible preferred stock, were converted into 28,453,228 shares of eFFECTOR Common Stock. The authorized shares, purchase price, number of shares and liquidation amount for each series of convertible preferred stock as of December 31, 2020, as adjusted for the Exchange Ratio, is as follows (in thousands, except share and per share amounts): Shares Purchase Shares Liquidation Convertible preferred stock: Series A 14,056,840 $ 4.05382 11,563,819 $ 46,878 Series B 11,071,448 $ 5.05806 10,154,819 $ 51,364 Series C 7,346,140 $ 5.32253 6,734,590 $ 35,845 Total 32,474,428 28,453,228 $ 134,087 Dividends Each holder of Old eFFECTOR’s non- O prior to and in preference to the payment of a dividend on Old eFFECTOR’s common stock (“Old eFFECTOR Common Stock”). No dividends have been declared to date. Liquidation Preferences In the event of any liquidation, Conversion Each share of O O price by the applicable conversion price at the time of conversion. Each share of O Old eFFECTOR Common Stock immediately upon (i) the closing of a firmly underwritten public offering pursuant to an effective registration statement under the Securities Act, covering the offer and sale of common stock for the account of O O O O O Ratio 0.09657 Voting The holders of the Old eFFECTOR Preferred Stock were entitled to one vote for each share of Old eFFECTOR Common Stock into which such shares of Old eFFECTOR Preferred Stock could then be converted; and with respect to such vote, such holders had full voting rights and powers equal to the voting rights and powers of the holders of the Old eFFECTOR Common Stock. Redemption The Old eFFECTOR Preferred Stock was not redeemable at the option of the holder or at the option of Old eFFECTOR. Old eFFECTOR’s convertible preferred stock was classified as temporary equity on the December 31, 2020 consolidated balance sheet instead of in stockholders’ equity (deficit) in accordance with authoritative guidance for the classification and measurement of redeemable securities. Upon certain change in control events that were outside of Old eFFECTOR’s control, including liquidation, sale or transfer of control of Old eFFECTOR, holders of the Old eFFECTOR Preferred Stock could cause its redemption. Old eFFECTOR determined not to adjust the carrying values of the Old eFFECTOR Preferred Stock to the liquidation preferences of such shares because of the uncertainty of whether or when such events would occur. Common Stock During the year ended December 31, 2021, the Company issued 93,542 of shares of common stock in connection with the exercise of stock options, for net proceeds of $0.1 million. During the year ended December 31, 2020, the Company issued 111,354 of shares of common stock in connection with the exercise of stock options, for net proceeds of $0.1 million. 2013 Equity Incentive Plan Prior to the Business Combination, Old eFFECTOR maintained its 2013 Equity Incentive Plan (the “2013 Plan”), under which Old eFFECTOR granted incentive stock options, restricted stock awards, and other stock-based non-employee Conversion of Awards In connection with the Business Combination, each option of Old eFFECTOR that was outstanding and unexercised immediately prior to the close date (whether vested or unvested) was converted into an option to acquire an adjusted number of shares of eFFECTOR common stock at an adjusted exercise price per share (the “Substitute Options”), based on the Exchange Ratio of approximately 0.09657, and will continue to be governed by substantially the same terms and conditions, including vesting, as were applicable to the former option. Each Substitute Option will be exercisable for a number of whole shares of Common Stock equal to the product of the number of shares of Old eFFECTOR common stock underlying such Old eFFECTOR option multiplied by the Exchange Ratio, and the per share exercise price of such Substitute Option will be equal to the quotient determined by dividing the exercise price per share of Old eFFECTOR common stock by the Exchange Ratio. In connection with the closing, 40,599,270 options to purchase shares of Old eFFECTOR common stock were exchanged for options to purchase an aggregate of 3,920,657 shares of Common Stock, with an as-adjusted share. 2021 Equity Incentive Plan and ESPP In connection with the consummation of the Business Combination on August 25, 2021, the Board of Directors approved the adoption of the 2021 Equity Incentive Plan (the “2021 Plan”). As of December 31, 2021, 6,508,048 shares of Common Stock are authorized for issuance pursuant to awards under the 2021 Plan, inclusive of any shares of Common Stock subject to stock options, restricted stock awards or other awards that were assumed in the Business Combination. As of December 31, 2021, 344,486 options to purchase common shares have been awarded and 6,201,340 shares remain available for issuance under the 2021 Plan. The 2021 Plan permits the granting of incentive stock options, restricted stock awards, other stock-based award or other cash-based awards to employees, directors, and non-employee At a special meeting of stockholders held on August 24, 2021, stockholders considered and approved the eFFECTOR Therapeutics, Inc. 2021 Employee Stock Purchase Plan (the “ESPP”). The ESPP provides for six-month If our capital structure changes because of a stock dividend, stock split or similar event, the number of shares that can be issued under the ESPP will be appropriately adjusted. No shares were issued under the ESPP as of December 31, 2021. Stock Options In May 2013, the Company adopted the 2013 Equity Incentive Plan (the “2013 Plan”), which was amended in February 2016. The 2013 non-statutory 2013 In August 2021, the Company adopted the 2021 Equity Incentive Plan (the “2021 Plan”). The 20 21 non-statutory There were zero and 132,974 shares available for grant under the 2013 Plan as of December 31, 2021 and December 31, 2020, respectively. In connection with the completion of the Business Combination and the adoption of the 2021 Plan, no further awards will be granted under the 2013 Plan. Options granted under the 2021 Plan are exercisable at various dates as determined upon grant and will expire no more than ten years from their date of grant, or in the case of certain non-statutory the Stock-Based Compensation Expense The Company recognized stock-based compensation expense specifically related to stock options of $1.0 million and $0.5 million for the years ended December 31, 2021 and 2020, respectively. The assumptions used in the Black-Scholes option pricing model to determine the fair value of the stock option grants were as follows: Year Ended December 31, 2021 2020 Risk-free interest rate 0.7% - 1.3% 0.3% - 1.0% Expected volatility 81% - 90% 87% - 93% Expected term (in years) 5.5 - 6.1 5.3 - 6.1 Expected dividend yield 0% 0% Risk-free interest rate. Expected volatility. Expected term. the time-to-vesting Expected dividend yield.

Earn-Out Shares

Earn-Out Shares	12 Months Ended
	Dec. 31, 2021
Earn Out Share [Abstract]
Earn-Out Shares	10. Earn-Out In accordance the two-year period Earn-Out Earn-Out Earn-Out Earn-Out The estimated fair value of the Earn-Out Shares the earn-out period December 31, As of August 25, 2021 at Initial Stock price $ 8.28 $ 16.98 Expected volatility 65.0 % 60.0 % Risk-free interest rate 0.6 % 0.2 % Forecast period (in years) 1.6 2.0 Cost of equity 20.0 % 20.0 % Old eFFECTOR Shareholders The Company has determined that the contingent obligation to issue Earn-Out Shares 815-40 the Earn-Out Shares Event The earn-out non-current earn-out Earn-out Earn-out $ 61,024 Incremental shares due to option holder forfeitures 16 Change in fair value - Closing Date through December 31, 2021 (48,910 ) Earn-out $ 12,130 Old eFFECTOR Option Holders The contingent obligation to issue Earn-Out Shares holder Earn-Out Shares share-based Earn-Out

License Agreements

License Agreements	12 Months Ended
	Dec. 31, 2021
License Agreement Disclosure [Abstract]
License Agreements	11. License Agreements In May 2013, the Company entered into an agreement with the Regents of the University of California (“UCSF”) which provides the Company with an exclusive license to UCSF’s patent rights in certain inventions (the “UCSF Translational Profiling Patent Rights”) relating to translational profiling laboratory techniques initially developed at UCSF. Under the agreement, the Company is permitted to research, develop, make and sell products that it discovers and develops utilizing the UCSF Translational Profiling Patent Rights, which the Company refers to as licensed products, and use certain licensed processes utilizing the UCSF Translational Profiling Patent Rights and to sublicense such licensed products and processes. Under the agreements, the Company is required to use commercially reasonable efforts to meet certain specified development, regulatory and commercial milestones related to the licensed products within specified one-time one-time service. In the event the Company sublicenses any of the UCSF Translational Profiling Patent Rights, the Company has agreed to pay a percentage of sublicense revenue received at specified rates that start at low double digit percentages and decrease to single digit percentages based on the elapsed time from the effective date of the agreement. Additionally, the Company has agreed to pay a low double digit percentage of any payments it receives from the sales of a licensed product discovered or developed by the Company under a collaboration agreement and a low double digit percentage of any net sales with respect to a licensed service. UCSF may terminate the agreement if the Company fails to perform or violates any material term of the agreement and fails to cure such nonperformance or violation within 60 days of notice from UCSF or in the event of the Company’s insolvency. The Company is currently in compliance with all material terms of the agreement. The Company may terminate the agreement upon 60 days’ written notice to UCSF and may terminate the UCSF Translational Profiling Patent Rights on a claim-by-claim, patent-by-patent country-by-country of the longest-lived patent right included in the UCSF Translational Profiling Patent Rights. Any terminations initiated by the Company does not relieve their obligation to pay royalties and milestones under the terms of the UCSF agreement. In addition one-time one-time payment,

Research Collaboration and Lice

Research Collaboration and License Agreement	12 Months Ended
	Dec. 31, 2021
Research and Development [Abstract]
Research Collaboration and License Agreement	12. Research Collaboration and License Agreement In December 2019, the Company entered into a Research Collaboration and License Agreement (the “Pfizer Agreement”) with Pfizer to research and develop small molecules that target eIF4E. Pursuant to the Pfizer Agreement, the Company granted Pfizer a worldwide, exclusive license, with a right to sublicense, under certain of the Company’s patents, know-how and materials, to use, develop, manufacture, commercialize, and otherwise exploit compounds or products targeting eIF4E, for any and all indications. Pursuant to the Pfizer Agreement, Pfizer granted the Company an option to co-fund and co-promote a single such licensed product under a profit and loss share arrangement in the United States. The option can be exercised prior to a specified time before the first patient is expected to be enrolled in a clinical trial intended to support an NDA for marketing approval. Under the Pfizer Agreement, the Company was responsible for initial research in collaboration with Pfizer, and Pfizer is responsible for all further development of the program, including submission of an IND and co-funding co-promotion co-developed Pursuant to the Pfizer Agreement, the Company received an upfront, one-time, non-refundable, non-creditable non-early co-funding co-promotion non-early non-early product-by-product co-promotion co-funding Unless earlier terminated, the Pfizer Agreement will continue in effect until the expiration of all Pfizer payment obligations. Except in the United States, if the Company exercises its co-funding co-promotion paid-up, Under the framework of ASC Topic 606, Revenue from Contracts with Customers, the Company identified two distinct performance obligations; 1) delivery of the license and 2) performance of future research activities specified within the research plan. The Company determined the standalone value of the license by calculating the present value of the probability weighted cash inflows to be generated from the Pfizer Agreement. These cash inflows include development and sales milestones and future royalties. The standalone value of the research activities was determined by identifying the market cost for services and supplies to perform such activities if it were to be outsourced to a third-party. The initial transaction price of $27.0 million was allocated to the two performance obligations on a relative standalone value basis, with $25.6 million allocated to the license and $1.4 million allocated to the research activities. The value attributable to the license was recognized upon delivery of the license to Pfizer and the value attributable to the research activities was recognized pro-rata During the year ended December 31, 2020, the Company received $42.0 million from Pfizer in connection with the Research and License Agreement for delivery of the license, reimbursement of research activities specific within the research plan, and achievement of the first development milestones. All $42.0 million was recognized as revenue for the year ended December 31, 2020. As of December 31, 2020, all future development and sales milestones (variable consideration) were fully constrained There was no revenue recorded in connection with this agreement for the year ended December 31, 2021 because all development and sales milestones (variable consideration) were fully constrained.

DARPA Grant Revenue

DARPA Grant Revenue	12 Months Ended
	Dec. 31, 2021
DARPA Grant Revenue Disclosure [Abstract]
DARPA Grant Revenue	13. DARPA Grant Revenue In April 2021, the Company entered into a Research Subaward Agreement with UCSF, whereby up to $ million in allowable costs are reimbursable for clinical and manufacturing activities related to zotatifin for the treatment of COVID-19 under the DARPA grant. Under the terms of Research Subaward Agreement, the Company is obligated to provide financial and technical reports to UCSF on a periodic basis. The subaward can be terminated by either party upon written notice and also in the event that DARPA suspends or terminates its award to UCSF. The Company recognized $ million of revenue under the DARPA grant in the year ended December 31, 2021 and in the year ended December 31, 2020. As of December 31, 2021 and December 31, 2020, the Company has a receivable of $ million and recorded as a receivable within prepaid expenses and other current assets on the consolidated balance sheets, respectively. The initial award period for the DARPA grant ended in December 2021 and we have submitted a request to DARPA to extend such award period, with the same maximum $ million reimbursement amount, to .

Commitments and Contingencies

Commitments and Contingencies	12 Months Ended
	Dec. 31, 2021
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	14. Commitments and Contingencies Leases The Company leased certain office and lab space in San Diego, California under a non-cancelable two-year non-cancelable In September 2021, the Company entered a non-cancelable The following table summarizes supplemental balance sheet information related to leases as of December 31, 2021 and December 31, 2020. December 31, December 31, Assets: Operating lease right-of-use $ 166 $ 92 Total right-of-use 166 92 Liabilities Operating lease liabilities, current 44 108 Operating lease liabilities, non-current 126 — Total operating lease liabilities $ 170 $ 108 As of December 31, 2021, the future minimum annual lease payments under the existing operating leases were as follows (in thousands, except for weighted-average remaining lease term and weighted-average discount rate): 2022 $ 55 2023 73 2024 62 Total remaining lease payments 190 Less: imputed interest (20 ) Total operating lease liabilities 170 Less: current portion (44 ) Long-term operating lease liabilities $ 126 Weighted-average remaining lease term ( in years 2.8 Weighted-average discount rate 8 % During the year ended December 31, 2021, the Company paid $0.1 million in lease payments, which were included in operating activities in the consolidated statements of cash flows. During the year ended December 31, 2020, the Company paid $0.7 million in lease payments, which were included in operating activities in the consolidated statements of cash flows.

Employee Benefits

Employee Benefits	12 Months Ended
	Dec. 31, 2021
Equity [Abstract]
Employee Benefits	15. Employee Benefits The Company has a defined contribution 401(k) plan available to eligible employees. Under the terms of the plan, employees may make voluntary contributions as a percent of compensation, limited to the maximum amount allowable under federal tax regulations. The Company, at its discretion, may make certain contributions to the 401(k) plan. Through December 31, 2021, the Company made no matching contributions.

Income Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2021
Income Tax Disclosure [Abstract]
Income Taxes	16. Income Taxes For the years ended December 31, 2021 and 2020, the Company recorded current income tax expense of zero and $0.4 million, respectively. Significant components of the Company’s net deferred tax assets are summarized as follows (in thousands): December 31, December 31, Deferred tax assets: Net operating loss carryforwards $ 36,898 $ 29,829 Intangibles 3,565 3,875 Accrued compensation 1,284 325 Credits 7,107 6,252 Fixed assets 6 40 Other, net 74 96 Right-of-use 36 23 Deferred tax assets 48,970 40,440 Deferred tax liabilities: Right-of-use (35 ) (19 ) Deferred tax liabilities (35 ) (19 ) Net deferred tax assets 48,935 40,421 Valuation allowance (48,935 ) (40,421 ) Net deferred tax assets $ — $ — A reconciliation of the income tax computed at the federal statutory tax rate to the expense for income taxes for the years ended December 31, 2021 and 2020 is as follows (in thousands): December 31, December 31, Tax at statutory rate $ 3,318 $ 3,058 State income taxes, net of federal benefits (1,853 ) 292 Change in valuation allowance 8,515 808 Uncertain tax positions 569 474 Gain on change in fair value of earn-out (10,271 ) — Permanent differences and other 636 47 Capitalized R&D 510 (3,836 ) Credits (1,424 ) (492 ) Income tax expense $ — $ 351 Management assesses all available evidence to estimate if sufficient future taxable income will be generated to use the existing deferred tax assets. The Company has experienced net losses since inception (aside from the years ended December 31, 2021 and December 31, 2020 when net income was realized as a result of a gain in fair value recognized associated with the earn-out liability and non-recurring revenue in connection with the Research Collaboration and License Agreement with Pfizer, respectively), and the revenue and income potential of the Company’s business and market are unproven. Due to the Company’s continuing research and development activities, the Company expects to continue to incur net losses into the foreseeable future. As such, the Company cannot conclude that it is more likely than not that its deferred tax assets will be realized. A valuation allowance of Utilization of net operating loss (“NOL”) and research and development (“R&D”) credit carryforwards may be subject to a substantial annual limitation due to ownership change limitations that may have occurred or that could occur in the future, as required by Section 382 of the Internal Revenue Code of 1986, as amended (the “Code”), as well as similar state and foreign provisions. These ownership changes may limit the amount of NOL and R&D credit carryforwards that can be utilized annually to offset future taxable income and tax, respectively. In general, an “ownership change” as defined by Section 382 of the Code results from a transaction or series of transactions over a three-year period resulting in an ownership change of more than 50 percentage points of the outstanding stock of a company by certain stockholders. Since the Company’s formation, the Company has raised capital through the issuance of capital stock on several occasions, which on its own or combined with the purchasing stockholders’ subsequent disposition of those shares, may have resulted in such an ownership change, or could result in an ownership change in the future. The Company completed a preliminary Code section 382 and 383 study from inception through December 31, 2020 and concluded that $1.8 million of federal and California net operating losses and million of federal R&D credits will expire unused. The Company removed deferred tax assets for net operating loss of $0.6 million and research credits of million from its deferred tax assets schedule and has recorded a corresponding decrease in the valuation allowance for 2020. The Company has not conducted the study after December 31, 2020. When the study is completed, the Company will adjust its deferred tax assets accordingly. Due to the existence of a full valuation allowance any subsequent ownership changes will not impact the Company’s effective tax rate. The 63.2 As of December 31, 2021, the Company had federal and California research and development (“R&D” tax) credit carryforwards of approximately $8.5 million and $3.8 million, respectively. The federal R&D tax credit carryforwards will begin to expire in 2032 The Company recognizes a tax benefit from an uncertain tax position when it is more likely than not that the position will be sustained upon examination, including resolutions of any related appeals or litigation processes, based on the technical merits. Income tax positions must meet a more likely than not recognition at the effective date to be recognized. A reconciliation of the beginning and ending amount of unrecognized tax benefits for 2021 and 2020, excluding interest and penalties, is as follows (in thousands): December 31, December 31, Balance at beginning of the year $ 7,623 $ 7,068 Additions/(reductions) for tax positions - prior year — — Increase related to current year positions 612 555 Balance at the end of the year $ 8,235 $ 7,623 For the years ended December 31, 2021 and 2020, the Company did not recognize any interest or penalties. The Company currently files income tax returns in California and with the U.S. Internal Revenue Service. The Company currently has no tax periods under examination by any jurisdiction. Due to the existence of net operating loss carryforwards, all tax periods from inception of the Company are open for examination by taxing authorities for all jurisdictions. Included in the balance of unrecognized tax benefits at December 31, 2021 is $6.8 million that, if recognized, would not impact the Company’s income tax expense (benefit) or effective tax rate as long as our deferred tax asset remains subject to a full valuation allowance. The Company does not expect any significant increases or decreases to our unrecognized tax benefits within the next 12 months.

Subsequent Events

Subsequent Events	12 Months Ended
	Dec. 31, 2021
Subsequent Events [Abstract]
Subsequent Events	17. Subsequent Events On January 24, 2022, the Company entered into an equity purchase agreement (the “Purchase Agreement”) and a registration rights agreement with Lincoln Park , 50.0 thirty-six 36 3.0 557,610 142,939 On February 22, 2022, the Company entered into an amendment to the Oxford LSA whereby the interest only period for the Term A Loans will end on March 1, 2024, instead of May 1, 2023. In connection with the amendment, the maturity of the Term A Loans was extended from March 18, 2026 to February 1, 2027. Additionally, Term B Loans will now become available to the Company after January 1, 2023, and upon achievement of certain clinical development milestones, until the earlier of (i) June 30, 2023, (ii) forty-five days after the occurrence of the Phase II Milestones, and (iii) the occurrence of an event of default. The interest-only period ends March 1, 2024, provided that upon the funding of the Term B Loans the end date will be extended to

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2021
Accounting Policies [Abstract]
Use of Estimates	Use of Estimates The Company’s consolidated financial statements are prepared in accordance with accounting principles generally accepted in the United States (“GAAP”). The preparation of the Company’s consolidated financial statements requires it to make estimates and assumptions that impact the reported amounts of assets, liabilities and expenses and the disclosure of contingent liabilities in the Company’s consolidated financial statements and accompanying notes. The most significant estimate in the Company’s consolidated financial statements relates to its clinical trial expense accruals. Management evaluates its estimates on an ongoing basis. Although these estimates are based on the Company’s historical experience, knowledge of current events and actions it may undertake in the future, actual results may ultimately materially differ from these estimates and assumptions.
Cash and Cash Equivalents	Cash and Cash Equivalents The Company considers all highly liquid investments with an original maturity of three months or less at the date of purchase to be cash equivalents. Cash equivalents primarily represent funds invested in readily available operating and money market funds.
Fair Value of Financial Instruments	Fair Value of Financial Instruments The carrying amounts of all cash equivalents, prepaid expenses and other assets, accounts payable and accrued liabilities are reasonable estimates of their fair value because of the short-term nature of these items. Based on the borrowing rates currently available to the Company for loans with similar terms, the Company believes the fair value of the term loans approximate their carrying value (see Note 7).
Concentration of Credit Risk and Other Risks and Uncertainties	Concentration of Credit Risk and Other Risks and Uncertainties Financial instruments, which potentially subject the Company to significant concentration of credit risk, consist primarily of cash and cash equivalents. The Company maintains deposits in a federally insured major financial institution in excess of federally insured limits. The Company has not experienced any losses in such accounts and management believes that the Company is not exposed to significant credit risk due to the financial position of the depository institution in which those deposits are held. The Company is subject to a number of risks similar to other biopharmaceutical companies, including, but not limited to, the need to obtain adequate additional funding, possible failure of current or future preclinical studies or clinical trials, reliance on third parties or partners to conduct its clinical trials, the need to obtain regulatory and marketing approvals for its drug candidates or to rely on partners to do so, competitors developing new technological innovations, the need to successfully commercialize and gain market acceptance of its drug candidates, the right to develop and commercialize drug candidates pursuant to the terms and conditions of the licenses granted to the Company, protection of proprietary technology, the ability to make milestone, royalty or other payments due under any license or collaboration agreements, and the need to secure and maintain adequate manufacturing arrangements with third parties. If the Company does not successfully commercialize or partner any of its drug candidates, it will be unable to generate product revenue or achieve profitability.
Property and Equipment	Property and Equipment Property and equipment are recorded at cost and depreciated or amortized using the straight-line method over the estimated useful lives of the assets (generally three
Long-Lived Assets	Long-Lived Assets The Company regularly reviews the carrying value and estimated lives of all of its long-lived assets, including property and equipment to determine whether indicators of impairment may exist which warrant adjustments to carrying values or estimated useful lives. Should an impairment exist, the impairment loss would be measured based on the excess over the carrying amount of the asset’s fair value. The Company has not recognized any impairment losses from inception through December 31, 2021.
Leases	Leases At the inception of a contractual arrangement, the Company determines whether the contract contains a lease by assessing whether there is an identified asset and whether the contract conveys the right to control the use of the identified asset in exchange for consideration over a period of time. If both criteria are met, the Company records the associated lease liability and corresponding right-of-use right-of-use right-of-use non-lease
Grant Revenue	Grant Revenue The Company’s grant revenues are derived from a grant with the Defense Advanced Research Projects Agency (“DARPA”) through the University of California, San Francisco (“UCSF”). The Company recognizes DARPA Grant revenue as reimbursable grant costs are incurred up to pre-approved
Research and Development Costs	Research and Development Costs Research and development expenses primarily consist of costs associated with the preclinical and clinical development of the Company’s product candidates. Research and development costs are expensed as incurred.
Clinical Trial Accruals and Preclinical Studies	Clinical Trial Accruals and Preclinical Studies The Company is required to estimate expenses resulting from our obligations under contracts with vendors and consultants, CROs and clinical sites in connection with conducting clinical trials and preclinical studies. The financial terms of these contracts are subject to negotiations which vary from contract to contract and may result in payment flows that do not match the periods over which materials or services are provided under such contracts. The Company reflects clinical trial and preclinical study expenses in the consolidated financial statements by matching those expenses with the period in which services and efforts are expended. The Company accounts for these expenses according to the progress of the clinical trial or preclinical study as measured by the timing of various aspects of the clinical trial, preclinical study, or related activities. The Company determines accrual estimates through review of the underlying contracts along with preparation of financial models taking into account correspondence with clinical and other key personnel and third-party service providers as to the progress of the clinical trials, preclinical studies, or other services being conducted. During the course of a clinical trial or preclinical study, the Company adjusts the rate of expense recognition if actual results differ from estimates.
Patent Costs	Patent Costs Costs related to filing and pursuing patent applications are recorded as general and administrative expense and expensed as incurred since recoverability of such expenditures is uncertain.
Revenue Recognition	Revenue Recognition The Company evaluates collaboration arrangements to determine whether units of account within the collaboration arrangement exhibit the characteristics of a vendor and customer relationship. For arrangements and units of account where a customer relationship exists, the Company applies the revenue recognition guidance. The Company recognizes revenue upon the transfer of promised goods or services to customers in an amount that reflects the consideration to which the Company expects to be entitled in exchange for those goods or services. To determine revenue recognition for contracts with customers the Company performs the following five steps: (i) identify the contract(s) with a customer; (ii) identify the performance obligations in the contract; (iii) determine the transaction price; (iv) allocate the transaction price to the performance obligations in the contract; and (v) recognize revenue when (or as) the Company satisfies the performance obligations. At contract inception, the Company assesses the goods or services promised within each contract and assesses whether each promised good or service is distinct and determines those that are performance obligations. The Company then recognizes as revenue the amount of the transaction price that is allocated to the respective performance obligation when (or as) the performance obligation is satisfied. If a license to the Company’s intellectual property is determined to be distinct from the other performance obligations identified in the arrangement, the Company recognizes revenues from non-refundable, For research and development services performed under a collaboration agreement in which the performance obligation is satisfied over time, the Company measures the progress of the activities using an input method. The input methods used are based on the effort expended or costs incurred toward the satisfaction of the related performance obligation. The Company estimates the amount of effort expended, including the time the Company estimates it will take to complete the activities, or costs incurred in a given period, relative to the estimated total effort or costs to satisfy the performance obligation. This results in a percentage that is multiplied by the consideration allocated to the research and development services to determine the amount of revenue recognized each period. This approach requires estimates and the use of significant judgement. If the estimates or judgements change over the course of the collaboration, they may affect the timing and amount of revenue recognized in the current and future periods.
Milestones	Milestones At the inception of each arrangement that includes milestone payments (variable consideration), the Company evaluates whether the milestones are considered probable of being reached and estimates the amount to be included in the transaction price using the most likely amount method. If it is probable that a significant revenue reversal would not occur, the re-evaluates catch-up
Royalties	Royalties For arrangements that include sales-based royalties, including milestone payments based on the level of sales, and for which the license is deemed to be the predominant item to which the royalties relate, the Company recognizes revenue at the later of (i) when the related sales occur, or (ii) when the performance obligation to which some or all of the royalty has been allocated has been satisfied (or partially satisfied). To date, the Company has not recognized any royalty revenue from any collaborative arrangement.
Income Taxes	Income Taxes The Company accounts for income taxes under the asset and liability method, which requires the recognition of deferred tax assets and liabilities for the expected future tax consequences of events that have been included in the consolidated financial statements. Under this method, deferred tax assets and liabilities are determined on the basis of the differences between the consolidated financial statements and tax basis of assets and liabilities using enacted tax rates in effect for the year in which the differences are expected to reverse. The effect of a change in tax rates on deferred tax assets and liabilities is recognized in income in the period that includes the enactment date. The Company recognizes deferred tax assets to the extent that the Company believes these assets are more likely than not to be realized. In making such a determination, management considers all available positive and negative evidence, including future reversals of existing taxable temporary differences, projected future taxable income, tax-planning As of December 31, 2021 and 2020, the Company maintained valuation allowances against its deferred tax assets as the Company concluded it had not met the “more likely than not” to be realized threshold. Changes in the valuation allowance when they are recognized in the provision for income taxes may result in a change in the estimated annual effective tax rate. The Company records uncertain tax positions on the basis of a two-step
Comprehensive Income	Comprehensive Income Net income and comprehensive income were the same for all periods presented; therefore, a separate statement of comprehensive income is not included in the accompanying consolidated financial statements.
Segment Reporting	Segment Reporting Operating segments are identified as components of an enterprise about which separate discrete financial information is available for evaluation by the chief operating decision-maker in making decisions regarding resource allocation and assessing performance. The Company and its chief operating decision-maker view the Company’s operations and manage its business in one operating segment.
Stock-Based Compensation	Stock-Based Compensation Expense Stock-based compensation expense represents the cost of the grant date fair value of employee stock option grants recognized over the requisite service period of the awards (usually the vesting period) on a straight- line basis. The Company estimates the fair value of stock option grants using the Black-Scholes option-pricing model. The Company accounts for stock options granted to non-employees The Black-Scholes option-pricing model requires the use of subjective assumptions, including the risk-free interest rate, the expected stock price volatility, the expected term of stock options, and the expected dividend yield. The fair value of the underlying common stock used within the Black-Scholes option-pricing model is based on the closing price of common stock on the date of grant.
Preferred Stock Warrants	Preferred Stock Warrants The Company had previously issued freestanding warrants to purchase shares of its convertible preferred stock. Since the underlying convertible preferred stock was classified outside of permanent equity, these warrants were classified as liabilities in the accompanying consolidated balance sheets. Warrants classified as liabilities are recorded at their estimated fair value on the date of issuance and are revalued at each subsequent balance sheet date, with fair value changes recognized in other income (expense), net in the accompanying consolidated statements of operations and comprehensive income. The Company estimates the fair value of these warrants using the Black-Scholes option pricing model.
Public and Private Placement Warrants	Public and Private Placement Warrants Upon completion of the Business Combination, the Company assumed public and private placement warrants that were issued by LWAC in connection with their IPO in January 2021 whereby holders of the public and private placement warrants are entitled to acquire common stock of the Company. The Company has concluded that the public warrants are equity-classified. Since the settlement value of the private placement warrants is dependent, in part, on who holds the warrants at the time of settlement, they are not considered indexed to the Company’s stock and are therefore recorded as liabilities. Warrants classified as liabilities are recorded at their estimated fair value on the date of issuance and are revalued at each subsequent balance sheet date, with fair value changes recognized in other income (expense), net in the accompanying consolidated statements of operations and comprehensive income. The Company estimates the fair value of these warrants using the Black-Scholes option pricing model.
Earn-out Shares	Earn-out In accordance with the Merger Agreement, 5,000,000 shares are contingently issuable to Old eFFECTOR stockholders and option holders upon the occurrence of the Triggering Event (see Note 3), defined within the Merger Agreement as the date on which the common stock price equals or exceeds $20.00 over at least 20 trading days out of 30 consecutive trading day period for the two-year period Earn-Out Shares the earn-out period The Company has determined that the contingent obligation to issue Earn-Out Shares 815-40 the Earn-Out Shares The Company has determined that the contingent obligation to issue Earn-Out Shares holder Earn-Out Shares
Recent Accounting Pronouncements	Recent Accounting Pronouncements From time to time, new accounting pronouncements are issued by the Financial Accounting Standards Board (“FASB”) or other standard setting bodies and adopted by the Company as of the specified effective date. Unless otherwise discussed, the Company believes, based on their preliminary assessment, that the impact of recently issued standards that are not yet effective will not have a material impact on their financial position or results of operations upon adoption. In August 2020, the FASB issued ASU 2020-06, Debt-Debt with Conversion and Other Options (Subtopic 470-20) 815-40)
Net Income Per Share	Net Income Per Share The Company computes net income per share in accordance with the FASB guidance for Earnings Per Share, which established standards regarding the computation of earnings per share by companies that have issued securities other than common stock that contractually entitle the holder to participate in earnings and dividends. The guidance requires earnings available to common shareholders for the period, after deduction of preferred stock preferences, to be allocated between the common and preferred shareholders based on their respective rights to receive dividends. The Company is not required to present basic and diluted net income per share for securities other than common stock; therefore, the net income per share amounts only pertain to the Company’s common stock. Basic net if-converted two-class The Company has used the treasury stock method to calculate diluted net income per share for the year ended December 31, 2021, as there are no participating securities as of December 31, 2021 (and were no participating securities in the period of net income during 2021). The Company used the two-class method for the year ended December 31, 2020, as the if-converted method was anti-dilutive. Diluted net income per share for the years ended December 31, 2021 and 2020 also reflects the assumed exercise of options outstanding during the period using the treasury stock method, to the extent dilutive. Warrants were included in the calculation of diluted net income per share for the years ended December 31, 2021 and 2020 to the extent the warrants were dilutive. As a result of the Business Combination, the Company has retroactively restated the weighted average shares outstanding prior to August 25, 2021, to give effect to the Exchange Ratio. The following table sets forth the computation of bas ic and diluted net income per share (in thousands, except share and per share data): For the Year Ended 2021 2020 Basic Net Income per share Net income $ 15,798 $ 14,211 Less: income allocated to participating securities — (14,045 ) Net income attributable to common shareholders $ 15,798 $ 166 Weighted average common shares outstanding - basic 15,105,851 1,410,549 Net income per share - basic $ 1.05 $ 0.12 Diluted Net Income per share Net income $ 15,798 $ 14,211 Less: income allocated to participating securities — (13,912 ) Net income attributable to common shareholders $ 15,798 $ 299 Weighted average common shares outstanding - basic 15,105,851 1,410,549 Weighted average effect of dilutive securities: Convertible preferred stock 18,556,453 — Stock options 2,341,759 1,244,300 Weighted average common shares outstanding - diluted 36,004,063 2,654,849 Net income per share - diluted $ 0.44 $ 0.11 Potentially dilutive securities as of December 31, 2021 and 2020 are as follows (in common stock equivalent shares): For the Year Ended 2021 2020 Series A Convertible Preferred Stock — 11,563,819 Series B Convertible Preferred Stock — 10,154,819 Series C Convertible Preferred Stock — 6,734,590 Series C Convertible Preferred Stock Warrants — 70,455 Public warrants 5,833,333 — Private placement warrants 181,667 — Earn-Out 5,000,000 — Unvested sponsor shares 300,000 — Stock options outstanding 403,278 770,150 Total 11,718,278 29,293,833

Summary of Significant Accoun_3

Summary of Significant Accounting Policies (Tables)	12 Months Ended
	Dec. 31, 2021
Accounting Policies [Abstract]
Summary of Basic and Diluted Net Income (Loss) Per Share	The following table sets forth the computation of bas ic and diluted net income per share (in thousands, except share and per share data): For the Year Ended 2021 2020 Basic Net Income per share Net income $ 15,798 $ 14,211 Less: income allocated to participating securities — (14,045 ) Net income attributable to common shareholders $ 15,798 $ 166 Weighted average common shares outstanding - basic 15,105,851 1,410,549 Net income per share - basic $ 1.05 $ 0.12 Diluted Net Income per share Net income $ 15,798 $ 14,211 Less: income allocated to participating securities — (13,912 ) Net income attributable to common shareholders $ 15,798 $ 299 Weighted average common shares outstanding - basic 15,105,851 1,410,549 Weighted average effect of dilutive securities: Convertible preferred stock 18,556,453 — Stock options 2,341,759 1,244,300 Weighted average common shares outstanding - diluted 36,004,063 2,654,849 Net income per share - diluted $ 0.44 $ 0.11
Summary of Antidilutive Securities Excluded from Computation of Earnings Per Share	Potentially dilutive securities as of December 31, 2021 and 2020 are as follows (in common stock equivalent shares): For the Year Ended 2021 2020 Series A Convertible Preferred Stock — 11,563,819 Series B Convertible Preferred Stock — 10,154,819 Series C Convertible Preferred Stock — 6,734,590 Series C Convertible Preferred Stock Warrants — 70,455 Public warrants 5,833,333 — Private placement warrants 181,667 — Earn-Out 5,000,000 — Unvested sponsor shares 300,000 — Stock options outstanding 403,278 770,150 Total 11,718,278 29,293,833

Business Combination (Tables)

Business Combination (Tables)	12 Months Ended
	Dec. 31, 2021
Business Combinations [Abstract]
Summary of common stock outstanding following the consummation of business combination	The following summarizes the common stock outstanding following the consummation of the Business Combination, PIPE Financing and the automatic cashless exercise of Old eFFECTOR warrants: Shares % Old eFFECTOR Stockholders 30,021,762 74.4 % LWAC Stockholders 521,358 1.3 % LWAC Founders (1) 3,756,250 9.3 % PIPE Investors 6,070,003 15.0 % Total 40,369,373 100.0 % (1) Excludes 300,000 Sponsor Shares subject to vesting that are not considered outstanding from an accounting perspective.

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	12 Months Ended
	Dec. 31, 2021
Summary of assets and liabilities measured at fair value on a recurring basis	The following table summarizes the Company’s assets and liabilities that require fair value measurements on a recurring basis and their respective input levels based on the fair value hierarchy as of December 31, 2021 and December 31, 2020 (in thousands): Fair Value Measurements Using December 31, Quoted Prices Significant Significant Assets Money market funds $ 49,702 $ 49,702 $ — $ — Total assets $ 49,702 $ 49,702 $ — $ — Liabilities Private placement warrant liability $ 678 $ — $ — $ 678 Earn-out 12,130 — — 12,130 Total liabilities $ 12,808 $ — $ — $ 12,808 Fair Value Measurements Using December 31, Quoted Prices Significant Significant Assets Money market funds $ 15,216 $ 15,216 $ — $ — Total assets $ 15,216 $ 15,216 $ — $ — Liabilities Preferred stock warrant liability $ 433 $ — $ — $ 433 Total liabilities $ 433 $ — $ — $ 433
Preferred Stock Warrant Liability [Member]
Summary of fair value measurements inputs	The following key assumptions were used in determining the fair value of the preferred stock warrant liability valued using the Black-Scholes option pricing model as of December 31, 2020: December 31, 2020 Fair value of Series C convertible preferred stock $ 0.70 Expected volatility 96.3 % Risk-free interest rate 0.7 % Expected term (in years) 7.7 Expected dividend yield —
Summary of change in fair value of preferred stock warrant liability	The following table presents activity for the preferred stock warrant liability measured at fair value using significant unobservable Level 3 inputs during the years ended December 31, 2021 and 2020 (in thousands): Series C Preferred Stock Balance at December 31, 2019 $ 442 Change in fair value (9 ) Balance at December 31, 2020 $ 433 Issuance of new warrants 271 Change in fair value 153 Warrant exercises (857 ) Balance at December 31, 2021 $ —
Private Placement Warrants Liability [Member]
Summary of fair value measurements inputs	The following key assumptions were used in determining the fair value of the private placement warrant liability valued using the Black-Scholes option pricing model as of December 31, 2021 and August 25, 2021: December 31, 2021 As of August 25, 2021 at Initial Measurement Common stock price $ 8.28 $ 16.98 Expected volatility 65.0 % 60.0 % Risk-free interest rate 1.3 % 0.8 % Expected term (in years) 4.7 5.0 Expected dividend yield — —
Summary of change in fair value of preferred stock warrant liability	The following table presents activity for the private placement warrant liability measured at fair value using significant unobservable Level 3 inputs during the year ended December 31, 2021 (in thousands): Private Placement Warrant Liability Private Placement Warrants liability - August 25, 2021 (closing date) $ 1,862 Change in fair value - Closing Date through December 31, 2021 (1,184 ) Private Placement Warrants liability at December 31, 2021 $ 678

Property and Equipment, net (Ta

Property and Equipment, net (Tables)	12 Months Ended
	Dec. 31, 2021
Property, Plant and Equipment [Abstract]
Summary of Property and equipment, net	Property and equipment, net consists of the following (in thousands): December 31, December 31, 2021 2020 Lab equipment $ 30 $ 30 Computer and office equipment 127 133 Furniture and fixtures 64 64 Construction in process 74 — 295 227 Less accumulated depreciation and amortization (204 ) (193 ) $ 91 $ 34

Accrued Expenses (Tables)

Accrued Expenses (Tables)	12 Months Ended
	Dec. 31, 2021
Payables and Accruals [Abstract]
Summary of Accrued expenses	Accrued expenses consist of the following (in thousands): December 31, December 31, 2021 2020 Employee compensation $ 1,343 $ 230 Research and development 1,115 755 Professional and outside services 452 44 Interest 133 598 Income taxes payable 351 351 Other 24 6 $ 3,418 $ 1,984

Term Loans (Tables)

Term Loans (Tables)	12 Months Ended
	Dec. 31, 2021
Debt Disclosure [Abstract]
Summary of Company's required future principal payments	Based on the outstanding principal amounts for the Company’s Term A Loans, the following table sets forth by year the Company’s required future principal payments as of December 31, 2021 (in thousands): As of December 31, 2021 2023 $ 4,444 2024 6,667 2025 6,667 2026 2,222 Required future principal payments $ 20,000 Unamortized debt discount (1,240 ) Non-current $ 18,760

Warrants (Tables)

Warrants (Tables)	12 Months Ended
	Dec. 31, 2021
Warrants and Rights Note Disclosure [Abstract]
Summary of Preferred stock warrants outstanding	The following table summarizes the outstanding warrants to purchase shares of preferred stock and the corresponding exercise price as of December 31, 2021 and December 31, 2020: December 31, December 31, Exercise Expiration Date Series C preferred stock warrants — 70,455 $ 5.33 August 31, 2028 Series C preferred stock warrants — — $ 5.33 March 19, 2031
Summary of Public and private placement warrants outstanding	The following table summarizes the number of outstanding public warrants and private placement warrants and the corresponding exercise price as of December 31, 2021 and December 31, 2020: December 31, December 31, Exercise Expiration Date Public warrants 5,833,333 — $ 11.50 August 24, 2026 Private placement warrants 181,667 — $ 11.50 August 24, 2026

Convertible Preferred Stock a_2

Convertible Preferred Stock and Stockholders' Deficit (Tables)	12 Months Ended
	Dec. 31, 2021
Redeemable Convertible Preferred Stock And Stockholders Equity [Abstract]
Summary of temporary equity	The authorized shares, purchase price, number of shares and liquidation amount for each series of convertible preferred stock as of December 31, 2020, as adjusted for the Exchange Ratio, is as follows (in thousands, except share and per share amounts): Shares Purchase Shares Liquidation Convertible preferred stock: Series A 14,056,840 $ 4.05382 11,563,819 $ 46,878 Series B 11,071,448 $ 5.05806 10,154,819 $ 51,364 Series C 7,346,140 $ 5.32253 6,734,590 $ 35,845 Total 32,474,428 28,453,228 $ 134,087
Schedule of assumptions used in the Black-Scholes option pricing model to determine the fair value of the stock option grants.	The assumptions used in the Black-Scholes option pricing model to determine the fair value of the stock option grants were as follows: Year Ended December 31, 2021 2020 Risk-free interest rate 0.7% - 1.3% 0.3% - 1.0% Expected volatility 81% - 90% 87% - 93% Expected term (in years) 5.5 - 6.1 5.3 - 6.1 Expected dividend yield 0% 0%
Summary of Company's stock option activity	A summary of the Company’s stock option activity under the plans is as follows (in thousands, except share and per share amounts and years): Shares Weighted- Weighted- Aggregate Outstanding at December 31, 2020 3,887,038 $ 1.41 6.6 $ 3,806 Granted 484,512 10.81 9.7 Exercised (98,936 ) 1.09 4.4 Cancelled (79,293 ) 6.13 8.3 Outstanding at December 31, 2021 4,193,321 $ 2.41 6.0 $ 26,115 Vested and exercisable at December 31, 2021 3,076,726 $ 1.43 5.0 $ 21,191
Schedule of Common Stock, Reserved for Future Issuance	Common stock reserved for future issuance consists of the following as of December 31, 2021 and December 31, 2020: December 31, December 31, Convertible preferred stock — 28,453,228 Stock options issued and outstanding 4,193,321 3,887,038 Preferred stock warrants issued and outstanding — 70,455 Public warrants issued and outstanding 5,833,333 — Private placement warrants issued and outstanding 181,667 — Earn-Out 5,000,000 — Unvested sponsor shares 300,000 — Authorized for future stock awards or option grants 6,201,340 132,974 Total 21,709,661 32,543,695

Earn-Out Shares (Tables)

Earn-Out Shares (Tables)	12 Months Ended
	Dec. 31, 2021
Earn Out Share [Abstract]
Schedule Of Estimated Fair Value Of The Earn Out Shares	The estimated fair value of the Earn-Out Shares the earn-out period December 31, As of August 25, 2021 at Initial Stock price $ 8.28 $ 16.98 Expected volatility 65.0 % 60.0 % Risk-free interest rate 0.6 % 0.2 % Forecast period (in years) 1.6 2.0 Cost of equity 20.0 % 20.0 %
Schedule Of Activity For Earn Out Liability	The following table presents activity for the earn-out Earn-out Earn-out $ 61,024 Incremental shares due to option holder forfeitures 16 Change in fair value - Closing Date through December 31, 2021 (48,910 ) Earn-out $ 12,130

Commitments and Contingencies (

Commitments and Contingencies (Tables)	12 Months Ended
	Dec. 31, 2021
Commitments and Contingencies Disclosure [Abstract]
Schedule of Supplemental Balance sheet Information related to Leases	The following table summarizes supplemental balance sheet information related to leases as of December 31, 2021 and December 31, 2020. December 31, December 31, Assets: Operating lease right-of-use $ 166 $ 92 Total right-of-use 166 92 Liabilities Operating lease liabilities, current 44 108 Operating lease liabilities, non-current 126 — Total operating lease liabilities $ 170 $ 108
Schedule of Future Minimum Rental Payments for Operating Leases	As of December 31, 2021, the future minimum annual lease payments under the existing operating leases were as follows (in thousands, except for weighted-average remaining lease term and weighted-average discount rate): 2022 $ 55 2023 73 2024 62 Total remaining lease payments 190 Less: imputed interest (20 ) Total operating lease liabilities 170 Less: current portion (44 ) Long-term operating lease liabilities $ 126 Weighted-average remaining lease term ( in years 2.8 Weighted-average discount rate 8 %

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2021
Income Tax Disclosure [Abstract]
Summary of company's net deferred tax assets	For the years ended December 31, 2021 and 2020, the Company recorded current income tax expense of zero and $0.4 million, respectively. Significant components of the Company’s net deferred tax assets are summarized as follows (in thousands): December 31, December 31, Deferred tax assets: Net operating loss carryforwards $ 36,898 $ 29,829 Intangibles 3,565 3,875 Accrued compensation 1,284 325 Credits 7,107 6,252 Fixed assets 6 40 Other, net 74 96 Right-of-use 36 23 Deferred tax assets 48,970 40,440 Deferred tax liabilities: Right-of-use (35 ) (19 ) Deferred tax liabilities (35 ) (19 ) Net deferred tax assets 48,935 40,421 Valuation allowance (48,935 ) (40,421 ) Net deferred tax assets $ — $ —
Summary of reconciliation of the income tax computed at the federal statutory tax rate to the expense (benefit) for income taxes	A reconciliation of the income tax computed at the federal statutory tax rate to the expense for income taxes for the years ended December 31, 2021 and 2020 is as follows (in thousands): December 31, December 31, Tax at statutory rate $ 3,318 $ 3,058 State income taxes, net of federal benefits (1,853 ) 292 Change in valuation allowance 8,515 808 Uncertain tax positions 569 474 Gain on change in fair value of earn-out (10,271 ) — Permanent differences and other 636 47 Capitalized R&D 510 (3,836 ) Credits (1,424 ) (492 ) Income tax expense $ — $ 351
Summary of reconciliation of the beginning and ending amount of unrecognized tax benefit	A reconciliation of the beginning and ending amount of unrecognized tax benefits for 2021 and 2020, excluding interest and penalties, is as follows (in thousands): December 31, December 31, Balance at beginning of the year $ 7,623 $ 7,068 Additions/(reductions) for tax positions - prior year — — Increase related to current year positions 612 555 Balance at the end of the year $ 8,235 $ 7,623

Organization and Basis of Pre_2

Organization and Basis of Presentation - Additional Information (Detail) $ in Thousands		Jan. 24, 2022USD ($)	Aug. 25, 2021	Dec. 31, 2021USD ($)	Dec. 31, 2020USD ($)	Jan. 31, 2022USD ($)	Dec. 31, 2019USD ($)	Apr. 01, 2019USD ($)
Organization consolidation and presentation of financial statements [Line Items]
Place of incorporation				DE
Date of incorporation				Oct. 2, 2020
Accumulated deficit				$ (120,901)	$ (136,699)			$ 15,500
Cash from operations				24,900
Cash and cash equivalents				$ 49,702	15,216		$ 3,427
Stock issued during period, value, new issues	[1]				$ 108
Subsequent Event [Member] | Lincoln Park Purchase Agreement [Member]
Organization consolidation and presentation of financial statements [Line Items]
Stock issued during period, value, new issues		$ 3,000
Common stock shares subscriptions remaining						$ 47,000
Term of purchase agreement		36 months
Locust Walk Acquisition Corp [Member]
Organization consolidation and presentation of financial statements [Line Items]
Stockholders' Equity Note, Stock Split, Conversion Ratio			0.09657
[1]	Historical shares and capital amounts have been retroactively restated for the reverse recapitalization as described in Note 1.

Summary of Significant Accoun_4

Summary of Significant Accounting Policies - Summary of Basic and Diluted Net Income (Loss) Per Share (Detail) - USD ($) $ / shares in Units, $ in Thousands		12 Months Ended
		Dec. 31, 2021	Dec. 31, 2020
Basic Net (Loss) Income per share
Net income	[1]	$ 15,798	$ 14,211
Less: income allocated to participating securities		0	(14,045)
Net income attributable to common shareholders		$ 15,798	$ 166
Weighted average common shares outstanding - basic		15,105,851	1,410,549
Net income (loss) per share—basic		$ 1.05	$ 0.12
Diluted Net income (Loss) per share
Net income	[1]	$ 15,798	$ 14,211
Less: income allocated to participating securities		0	(13,912)
Net income attributable to common shareholders		$ 15,798	$ 299
Weighted average common shares outstanding - basic		15,105,851	1,410,549
Weighted average effect of dilutive convertible preferred stock		18,556,453	0
Weighted average effect of dilutive stock options		2,341,759	1,244,300
Weighted average common shares outstanding - diluted		36,004,063	2,654,849
Net income per share - diluted		$ 0.44	$ 0.11
[1]	Historical shares and capital amounts have been retroactively restated for the reverse recapitalization as described in Note 1.

Summary of Significant Accoun_5

Summary of Significant Accounting Policies - Summary of Antidilutive Securities Excluded from Computation of Earnings Per Share (Detail) - shares	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share, amount	11,718,278	29,293,833
Series A Preferred Stock [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share, amount	0	11,563,819
Series B Preferred Stock [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share, amount	0	10,154,819
Series C Preferred Stock [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share, amount	0	6,734,590
Series C Convertible Preferred Stock Warrants [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share, amount	0	70,455
Public warrants
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share, amount	5,833,333	0
Private Placement Warrants
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share, amount	181,667	0
Earn-Out Shares
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share, amount	5,000,000	0
Unvested sponsor shares
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share, amount	300,000	0
Stock Options Outstanding
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share, amount	403,278	770,150

Summary of Significant Accoun_6

Summary of Significant Accounting Policies - Additional Information (Detail) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2021USD ($)segment$ / sharesshares	Dec. 31, 2020USD ($)$ / sharesshares	Sep. 30, 2021
Percentage of liability refund adjustment from settlement with taxing authority	50.00%
Impairment of long lived assets	$ 0
Lessee, Operating lease, Term of contract			3 years
Revenue, Information used to assess variable consideration constraint	At the inception of each arrangement that includes milestone payments (variable consideration), the Company evaluates whether the milestones are considered probable of being reached and estimates the amount tobe included in the transaction price using the most likely amount method. If it is probable that a significant revenue reversal would not occur, the associated milestone value is included in the transaction price.
Revenue, Information used to allocate transaction price	The transaction price is then allocated to each performance obligation on a relative stand-alone selling price basis
Collaboration revenue	$ 0	$ 42,000
Number of operating segment | segment	1
Common stock, shares issued | shares	40,689,975	1,445,065
Common stock price per share | $ / shares	$ 0.0001	$ 0.0001
Trading days required for entitlement of common stock	30 days
Consecutive Trading Days Required For Entitlement Of Common Stock	20 days
Participating Securities | shares	0
Undistributed Earnings (Loss) Allocated to Participating Securities, Basic	$ 0	$ 14,045
Royalty [Member]
Collaboration revenue	$ 0
Maximum [Member]
Property, plant and equipment, Useful life	5 years
Minimum [Member]
Property, plant and equipment, Useful life	3 years
Lessee, Operating lease, Term of contract	1 year
Earn-Out Shares
Common stock, shares issued | shares	5,000,000
Common stock price per share | $ / shares	$ 20
Trading days required for entitlement of common stock	20 days
Consecutive Trading Days Required For Entitlement Of Common Stock	30 years

Business Combination - Addition

Business Combination - Additional Information (Detail) $ / shares in Units, $ in Thousands		Aug. 25, 2021USD ($)$ / sharesshares	Dec. 31, 2021USD ($)$ / shares	Dec. 31, 2020USD ($)
Business Acquisition [Line Items]
Trading Days Required For Entitlement Of Common Stock 1			30 days
Proceeds from cash acquired through acquisition and PIPE offering | $		$ 67,000
Proceeds from business combination		52,900
Cash acquired		6,300
Issuance of common stock	[1]			$ 108
Transaction costs paid by SPAC in business combination		11,100
Business acquisition transaction cost		$ 3,000
Liabilities			$ 36,772	$ 15,725
Earn-Out Shares
Business Acquisition [Line Items]
Exchange ratio of outstanding stock and options		0.09657
Old eFFECTOR Stockholders
Business Acquisition [Line Items]
Preferred stock conversion ratio		0.09657
Shares issued on conversion | shares		30,021,762
Exchange ratio of outstanding stock and options		0.09657
Option to purchase common stock | shares		3,920,657
Weighted average exercise price of stock options that were exchanged | $ / shares		$ 1.56
Old eFFECTOR Stockholders | Earn-Out Shares
Business Acquisition [Line Items]
Contingently issuable shares description		Former holders of shares of Old eFFECTOR common stock (including shares received as a result of the conversion of Old eFFECTOR preferred stock and the exercise of Old eFFECTOR warrants) and former holders of options to purchase shares of Old eFFECTOR will also be entitled to receive their pro rata share of up to 5,000,000 earn-out shares (the “Earn-Out Shares”) of Common Stock if, on or prior to August 26, 2023, the closing share price of shares of common stock equals or exceeds $20.00 over at least 20 trading days within a 30-day trading period (the “Triggering Event”) and, in respect of each former holder of Old eFFECTOR stock options, such holder continues to provide services to the Company or one of its subsidiaries at the time of such Triggering Event. The Earn-Out Shares will also be earned and issuable in the event of a change in control of the Company on or prior to August 26, 2023 that results in the holders of common stock receiving a per-share price equal to or in excess of $20.00.
Contingently issuable shares issued to shareholders and option holders | shares		5,000,000
Old eFFECTOR Stockholders | Earn-Out Shares | Maximum
Business Acquisition [Line Items]
Trading Days Required For Entitlement Of Common Stock 1		30 days
Old eFFECTOR Stockholders | Earn-Out Shares | Minimum
Business Acquisition [Line Items]
Trigger price of common stock for issuance of earnout shares | $ / shares		$ 20
Trading Days Required For Entitlement Of Common Stock 1		20 days
Old eFFECTOR Stockholders | Common Stock [Member]
Business Acquisition [Line Items]
Common stock up on conversion | shares		4,056,250
PIPE Investor
Business Acquisition [Line Items]
Business acquisition, equity interest issued or issuable, number of shares | shares		6,070,003
Business acquisition share price | $ / shares		$ 10	$ 10
Business acquisition, equity interest issued or issuable value assigned		$ 60,700
Stock issued, Shares, Acquisitions | shares		40,669,373
Stock Outstanding During Period Shares Acquisitions | shares		40,369,373
LWAC Stockholders
Business Acquisition [Line Items]
Business acquisition, equity interest issued or issuable, number of shares | shares		10,347,611
Liabilities		$ 900
LWAC Stockholders | Common Stock Subject to Vesting
Business Acquisition [Line Items]
Common stock up on conversion | shares		300,000
LWAC Stockholders | Common Stock Subject to Vesting | Maximum
Business Acquisition [Line Items]
Trading Days Required For Entitlement Of Common Stock 1		30 days
LWAC Stockholders | Common Stock Subject to Vesting | Minimum
Business Acquisition [Line Items]
Trading Days Required For Entitlement Of Common Stock 1		20 days
Trigger price of common stock for vesting of unvested shares | $ / shares		$ 15
Private Investment In Public Entity Offering [Member]
Business Acquisition [Line Items]
Issuance of common stock		$ 60,700
[1]	Historical shares and capital amounts have been retroactively restated for the reverse recapitalization as described in Note 1.

Business Combination - Summary

Business Combination - Summary of common stock outstanding following the consummation of business combination (Detail)	12 Months Ended
	Dec. 31, 2021shares
Business Acquisition [Line Items]
Common stock, shares outstanding	40,369,373
Percentage of ownership	100.00%
Old eFFECTOR Stockholders
Business Acquisition [Line Items]
Common stock, shares outstanding	30,021,762
Percentage of ownership	74.40%
LWAC Stockholders
Business Acquisition [Line Items]
Common stock, shares outstanding	521,358
Percentage of ownership	1.30%
LWAC Founders
Business Acquisition [Line Items]
Common stock, shares outstanding	3,756,250	[1]
Percentage of ownership	9.30%	[1]
PIPE Investors
Business Acquisition [Line Items]
Common stock, shares outstanding	6,070,003
Percentage of ownership	15.00%
[1]	Excludes 300,000 Sponsor Shares subject to vesting that are not considered outstanding from an accounting perspective.

Business Combination - Summar_2

Business Combination - Summary of common stock outstanding following the consummation of business combination (Parenthetical) (Detail) - shares	Dec. 31, 2021	Dec. 31, 2020
Business Combinations [Abstract]
Unvested Shares Held By Sponsors	300,000	0

Fair Value Measurements - Summa

Fair Value Measurements - Summary of Assets And Liabilities Measured At Fair Value On Recurring Basis (Detail) - Fair Value, Recurring - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Assets:
Money market funds	$ 49,702	$ 15,216
Total assets	49,702	15,216
Liabilities:
Preferred stock warrant liability	678	433
Earn Out Liability	12,130
Total liabilities	12,808	433
Fair Value Inputs Level 1
Assets:
Money market funds	49,702	15,216
Total assets	49,702	15,216
Liabilities:
Preferred stock warrant liability	0	0
Earn Out Liability	0
Total liabilities	0	0
Fair Value Inputs Level 3
Assets:
Money market funds	0	0
Total assets	0	0
Liabilities:
Preferred stock warrant liability	678	433
Earn Out Liability	12,130
Total liabilities	$ 12,808	$ 433

Fair Value Measurements - Sum_2

Fair Value Measurements - Summary of fair value measurements inputs of preferred stock warrant liability (Detail) - Preferred Stock Warrant Liability [Member]	Dec. 31, 2020yr$ / shares
Series C Convertible Preferred Stock [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Measurement Input | $ / shares	0.70
Expected volatility
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Measurement Input	96.3
Risk-free interest rate
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Measurement Input	0.7
Expected term (in years)
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Measurement Input | yr	7.7
Dividend Yield
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Measurement Input	0

Fair Value Measurements - Sum_3

Fair Value Measurements - Summary of change in fair value of preferred stock warrant liability (Detail) - Preferred Stock Warrant Liability [Member] - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Class of Warrant or Right [Line Items]
Fair value, Beginning Balance	$ 433	$ 442
Issuance of new warrants	271
Change in fair value	153	(9)
Warrant exercises	(857)
Fair value, Ending Balance	$ 0	$ 433

Fair Value Measurements - Sum_4

Fair Value Measurements - Summary of fair value measurements inputs of private placement warrant liability (Detail) - Private Placement Warrant Liability	Dec. 31, 2021$ / sharesyr	Aug. 25, 2021$ / sharesyr
Common stock price
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Measurement Input | $ / shares	8.28	16.98
Expected volatility
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Measurement Input	65	60
Risk-free interest rate
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Measurement Input	1.3	0.8
Expected term (in years)
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Measurement Input | yr	4.7	5
Dividend Yield
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Measurement Input	0	0

Fair Value Measurements - Sum_5

Fair Value Measurements - Summary of change in fair value of private placement warrant liability (Detail) - Private Placement Warrant Liability $ in Thousands	4 Months Ended
	Dec. 31, 2021USD ($)
Fair value, Beginning Balance	$ 1,862
Change in fair value	(1,184)
Fair value, Ending Balance	$ 678

Fair Value Measurements - Addit

Fair Value Measurements - Additional Information (Detail) $ in Thousands	12 Months Ended
	Dec. 31, 2021USD ($)
Fair Value, Inputs, Level 1, 2 and 3 [Member]
Fair value, net derivative asset (liability) measured on recurring basis, unobservable inputs reconciliation, transfers, net	$ 0

Property and Equipment, net - S

Property and Equipment, net - Summary of Property and equipment, net (Detail) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	$ 295	$ 227
Less accumulated depreciation and amortization	(204)	(193)
Total	91	34
Lab equipment
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	30	30
Computer and office equipment
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	127	133
Furniture and fixtures
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	64	$ 64
Leasehold improvements
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	$ 74

Property and Equipment, net - A

Property and Equipment, net - Additional Information (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Depreciation and amortization expense	$ 24	$ 160
Property and Equipment, net [Member]
Depreciation and amortization expense	$ 24,000	$ 200

Accrued Expenses - Summary of A

Accrued Expenses - Summary of Accrued expenses (Detail) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Accrued Liabilities, Current [Abstract]
Employee compensation	$ 1,343	$ 230
Research and development	1,115	755
Professional and outside services	452	44
Interest	133	598
Income taxes payable	351	351
Other	24	6
Total	$ 3,418	$ 1,984

Term Loans - Additional informa

Term Loans - Additional information (Details) $ / shares in Units, $ in Thousands	Feb. 22, 2022	Dec. 31, 2021USD ($)$ / sharesshares	Aug. 25, 2021shares	Aug. 31, 2018USD ($)	Feb. 28, 2022	Mar. 31, 2021USD ($)TRANCHE	Dec. 31, 2021USD ($)$ / sharesshares	Dec. 31, 2020USD ($)shares	Aug. 31, 2019USD ($)
Debt Instrument [Line Items]
Ceiling limit of maximum percentage amount to be paid on aggregate principal amount				5.50%
Class of warrants, Exercise price per share | $ / shares		$ 5.33					$ 5.33
Effective interest rate								6.50%
Long term debt debt gross		$ 18,760					$ 18,760
Long term det net of unamortized debt discounts		20,000					20,000
Repayment of term loans							13,940	$ 2,000
Loss on debt extinguishment							492	0
Accrued Final Payment On Term Loans		$ 1,100					$ 1,100	$ 0
Prime Rate [Member]
Debt Instrument [Line Items]
Effective interest rate								1.50%
Series C Preferred Stock [Member]
Debt Instrument [Line Items]
Number of shares subject to each warrant | shares		46,970					46,970
Class of warrants, Exercise price per share | $ / shares		$ 5.33					$ 5.33
Debt Instrument, Term Loan A [Member]
Debt Instrument [Line Items]
Effective interest rate								9.10%
Debt Instrument, Term Loan B. [Member]
Debt Instrument [Line Items]
Effective interest rate								9.00%
Loan and Security Agreement [Member]
Debt Instrument [Line Items]
Line of Credit Facility, Maximum borrowing amount				$ 20,000
Number of shares subject to each warrant | shares								35,227
Line of Credit Facility, Interest Rate Description				The Term Loans had an interest-only period that commenced upon the borrowing of each tranche of the Term Loans with interest due and payable upon the first day of each month. The interest-only period ended August 31, 2020.
Loan and Security Agreement [Member] | Less Than One Year From The Date Of Loan Agreement [Member]
Debt Instrument [Line Items]
Prepayment fee as a percentage of the outstanding principal						3.00%
Loan and Security Agreement [Member] | Greater Than One Year And Less Than Two Years From The Date Of Loan Agreement [Member]
Debt Instrument [Line Items]
Prepayment fee as a percentage of the outstanding principal						2.00%
Loan and Security Agreement [Member] | Later Than Two Years And Not Later Than Three Years From The Date Of Loan Agreement [Member]
Debt Instrument [Line Items]
Prepayment fee as a percentage of the outstanding principal						1.00%
Loan and Security Agreement [Member] | Later Than Three Years From The Date Of Loan Agreement [Member]
Debt Instrument [Line Items]
Prepayment fee as a percentage of the outstanding principal						0.00%
Loan and Security Agreement [Member] | Silicon Valley Bank [Member]
Debt Instrument [Line Items]
Unamortized debt discounts		$ 200					$ 200
Long term debt debt gross								$ 13,000
Loss on debt extinguishment						$ 500
Prepayment fees paid in respect of term loan						100
Debt Issuance Costs, Net								12,900
Amortization of Debt Discount (Premium)							$ 200	$ 1,300
Accrued Final Payment On Term Loans						37,000
Loan and Security Agreement [Member] | Oxford Finance LLC [Member]
Debt Instrument [Line Items]
Debt instrument, face amount						$ 30,000
Long term debt variable interest rate percentage						7.70%
Number Of Tranches | TRANCHE						2
Loan and Security Agreement [Member] | Oxford Finance LLC [Member] | Subsequent Event [Member]
Debt Instrument [Line Items]
Long term debt maturity date					Feb. 1, 2027
Line of Credit Facility, Interest Rate Description					The Term A Loans have an interest-only period that commences upon the borrowing with interest due and payable upon the first day of each month. Prior to the execution of the amendment in February 2022, the interest-only period ended May 1, 2023
Loan and Security Agreement [Member] | Oxford Finance LLC [Member] | Warrants To Purchase To Series C Redeemable Convertible Stock [Member]
Debt Instrument [Line Items]
Number of shares subject to each warrant | shares		37,575					37,575
Class of warrants, Exercise price per share | $ / shares		$ 5.33					$ 5.33
Loan and Security Agreement [Member] | Prime Rate [Member] | Oxford Finance LLC [Member]
Debt Instrument [Line Items]
Debt instrument variable interest rate spread						4.45%
Loan and Security Agreement [Member] | Common Stock [Member] | Silicon Valley Bank [Member]
Debt Instrument [Line Items]
Conversion of Stock, Shares Converted | shares			16,477
Loan and Security Agreement [Member] | Common Stock [Member] | Oxford Finance LLC [Member]
Debt Instrument [Line Items]
Conversion of Stock, Shares Converted | shares							17,575
Loan and Security Agreement [Member] | Debt Instrument, Term Loan A [Member]
Debt Instrument [Line Items]
Line of Credit Facility, Current borrowing amount				$ 7,500
Loan and Security Agreement [Member] | Debt Instrument, Term Loan A [Member] | Oxford Finance LLC [Member]
Debt Instrument [Line Items]
Unamortized debt discounts		$ 1,500					$ 1,500
Long term debt debt gross		20,000				$ 20,000	20,000
Long term det net of unamortized debt discounts		$ 18,800					$ 18,800
Proceeds from long term debt net of issuance costs						12,500
Cut off date before which the interest on the term loan shall be paid		Mar. 1, 2024
Long term debt maturity date		Mar. 18, 2026					Mar. 18, 2026
Amortization of Debt Discount (Premium)							$ 1,500
Loan and Security Agreement [Member] | Debt Instrument, Term Loan A [Member] | Oxford Finance LLC [Member] | Subsequent Event [Member]
Debt Instrument [Line Items]
Cut off date before which the interest on the term loan shall be paid	May 1, 2023
Long term debt maturity date	Feb. 1, 2027
Extended Cut Off Date Before Which The Interest On Term Loan Paid					May 1, 2024
Loan and Security Agreement [Member] | Debt Instrument, Term Loan B. [Member]
Debt Instrument [Line Items]
Line of Credit Facility, Current borrowing amount				7,500					$ 7,500
Loan and Security Agreement [Member] | Debt Instrument, Term Loan B. [Member] | Oxford Finance LLC [Member]
Debt Instrument [Line Items]
Debt instrument, face amount						10,000
Proceeds from long term debt net of issuance costs						7,400
Number of days within which a portion of term loan will be available subject to achievement of milestone					45 days
Loan and Security Agreement [Member] | Debt Instrument, Term Loan B. [Member] | Oxford Finance LLC [Member] | Subsequent Event [Member]
Debt Instrument [Line Items]
Number of days within which a portion of term loan will be available subject to achievement of milestone	45 days
Cut off date before which the interest on the term loan shall be paid	Mar. 1, 2024				Mar. 1, 2024
Line of Credit Facility, Initiation Date	Jun. 30, 2023				Jun. 30, 2023
Extended Cut Off Date Before Which The Interest On Term Loan Paid					Mar. 1, 2025
Cut off Date In which Debt is Available	Jan. 1, 2023				Jan. 1, 2023
Loan and Security Agreement [Member] | Debt Instrument, Term Loan C [Member]
Debt Instrument [Line Items]
Line of Credit Facility, Current borrowing amount				$ 5,000
Loan and Security Agreement [Member] | Debt Instrument Term Loan A And B [Member] | Silicon Valley Bank [Member]
Debt Instrument [Line Items]
Repayment of term loans						11,500
Term loan final payment						$ 800
Term Loan Final Payment Percentage Of Original Principal Amount						1.00%

Term Loans - Summary of Company

Term Loans - Summary of Company's required future principal payments (Details) $ in Thousands	Dec. 31, 2021USD ($)
Schedule Of Debt Instrument Future Principal Payments [Line Items]
2023	$ 4,444
2024	6,667
2025	6,667
2026	2,222
Required future principal payments	20,000
Unamortized debt discount	(1,240)
Non-current term loans, net as of December 31, 2021	$ 18,760

Warrants - Additional Informati

Warrants - Additional Information (Detail) - $ / shares	12 Months Ended
	Dec. 31, 2021	Aug. 25, 2021
Exercise price of warrants	$ 5.33
Preferred Stock Warrants [Member]
Warrants exercise		50,529
Public Warrants and Private Placement Warrants [Member]
Warrants exercisable term from the date of completion of business combination	30 days
Warrants and rights outstanding, term	5 years
Class of warrants, redemption price per unit	$ 0.01
Class of warrants, redemption notice period	30 days
Share price	$ 18
Number of consecutive trading days for determining share price	20 days
Number of trading days to determine share price	30 days
Exercise price of warrants	$ 11.50

Warrants - Summary of Preferred

Warrants - Summary of Preferred stock warrants outstanding (Detail)	12 Months Ended
	Dec. 31, 2021$ / sharesshares
Class of Stock [Line Items]
Exercise price of warrants	$ 5.33
Expiration Date	Mar. 19, 2031
Series C Preferred Stock Warrant [Member]
Class of Stock [Line Items]
Warrants and rights outstanding | shares	70,455
Exercise price of warrants	$ 5.33
Expiration Date	Aug. 31, 2028

Warrants - Schedule of Public a

Warrants - Schedule of Public and private placement warrants outstanding (Detail)	12 Months Ended
	Dec. 31, 2021$ / sharesshares
Class of Warrant or Right [Line Items]
Exercise price of warrants	$ 5.33
Expiration date	Mar. 19, 2031
Public Warrants [Member]
Class of Warrant or Right [Line Items]
Class of Warrant or Right, Outstanding | shares	5,833,333
Exercise price of warrants	$ 11.50
Expiration date	Aug. 24, 2026
Private Placement Warrants [Member]
Class of Warrant or Right [Line Items]
Class of Warrant or Right, Outstanding | shares	181,667
Exercise price of warrants	$ 11.50
Expiration date	Aug. 24, 2026

Convertible Preferred Stock a_3

Convertible Preferred Stock and Stockholders' Deficit - Additional Information (Detail)		Aug. 25, 2021$ / sharesshares	Apr. 01, 2019USD ($)$ / sharesshares	Dec. 31, 2021USD ($)$ / sharesshares	Dec. 31, 2020USD ($)$ / sharesshares
Redeemable Convertible Preferred Stock And Stockholders Equity [Line Items]
Percentage of votes in terms of shares held by the holders of redeemable convertible preferred stock needed to approve conversion into common stock				70.00%	70.00%
Proceeds from the exercise of stock options | $				$ 56,000	$ 108,000
Stock option exercises, net (Shares)				98,936	111,354
Share-based Payment Award, Expiration Period				10 years	10 years
Allocated share based compensation expense | $				$ 1,000,000	$ 500,000
Retained Earnings (Accumulated Deficit) | $			$ 15,500,000	$ (120,901,000)	$ (136,699,000)
Stockholders' Equity Note, Stock Split			10:1
Preferred stock, shares authorized		100,000,000		100,000,000	0
Preferred stock, par value | $ / shares		$ 0.0001		$ 0.0001	$ 0.0001
Preferred stock, shares issued				0	0
Preferred stock, shares outstanding		28,453,228		0	0
Convertible preferred stock exchange ratio		0.09657
Shares purchased for award		3,920,657
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period				3 years
Fair value of vested option | $				$ 1,100,000	$ 400,000
Unrecognized compensation cost related to outstanding employee options | $				$ 3,200,000
Expected term (in years)				2 years 4 months 24 days
Unrecognized compensation cost related to outstanding nonemployee options | $				$ 700,000
Outstanding non employee expense expected period				1 year 8 months 12 days
Common Stock [Member]
Redeemable Convertible Preferred Stock And Stockholders Equity [Line Items]
Stock option exercises, net (Shares)	[1]			93,542
Stock issued during period shares	[1]				111,354
Stock Issued During Period, Shares, Stock Splits			366,845
Preferred stock, shares outstanding		28,453,228
Maximum [Member]
Redeemable Convertible Preferred Stock And Stockholders Equity [Line Items]
Expected term (in years)				6 years 1 month 6 days	6 years 1 month 6 days
Minimum [Member]
Redeemable Convertible Preferred Stock And Stockholders Equity [Line Items]
Expected term (in years)				5 years 6 months	5 years 3 months 18 days
Share-based Payment Arrangement, Employee [Member]
Redeemable Convertible Preferred Stock And Stockholders Equity [Line Items]
Weighted-average grant date fair value | $ / shares				$ 4.75	$ 1.48
Share-based Payment Arrangement, Nonemployee [Member]
Redeemable Convertible Preferred Stock And Stockholders Equity [Line Items]
Weighted-average grant date fair value | $ / shares				$ 8.71	$ 0.98
Share-based Payment Arrangement, Tranche Two [Member]
Redeemable Convertible Preferred Stock And Stockholders Equity [Line Items]
Share based compensation by share based payment award purchase price of common stock as a percentage of fair value				25.00%
Share-based Payment Arrangement [Member]
Redeemable Convertible Preferred Stock And Stockholders Equity [Line Items]
Intrinsic value of options exercised | $				$ 700,000	$ 200,000
Two Thousand And Thirteen Amended Equity Incentive Plan [Member]
Redeemable Convertible Preferred Stock And Stockholders Equity [Line Items]
Shares authorized				6,508,048
Shares grants				6,201,340
Stock options outstanding		3,920,657
Shares purchased for award				344,486
Two Thousand And Thirteen Amended Equity Incentive Plan [Member] | Share-based Payment Arrangement, Tranche One [Member]
Redeemable Convertible Preferred Stock And Stockholders Equity [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Expiration Date				25.00%
Shares purchased for award		40,599,270
Two Thousand And Thirteen Amended Equity Incentive Plan [Member] | Share-based Payment Arrangement, Tranche Two [Member]
Redeemable Convertible Preferred Stock And Stockholders Equity [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Expiration Date				25.00%	25.00%
Two Thousand And Thirteen Amended Equity Incentive Plan [Member] | Share-based Payment Arrangement, Tranche Three [Member]
Redeemable Convertible Preferred Stock And Stockholders Equity [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Expiration Date				25.00%
Two Thousand And Thirteen Amended Equity Incentive Plan [Member] | Share Based Payment Award Tranche Four [Member]
Redeemable Convertible Preferred Stock And Stockholders Equity [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Expiration Date				25.00%
Two Thousand And Thirteen Amended Equity Incentive Plan [Member] | Incentive Stock Options [Member]
Redeemable Convertible Preferred Stock And Stockholders Equity [Line Items]
Share based compensation by share based payment award purchase price of common stock as a percentage of fair value				100.00%	100.00%
Two Thousand And Thirteen Amended Equity Incentive Plan [Member] | Holders Of Ten Percent Or More Of All Classes Of Common Stock [Member] | Incentive Stock Options [Member]
Redeemable Convertible Preferred Stock And Stockholders Equity [Line Items]
Share based compensation by share based payment award purchase price of common stock as a percentage of fair value				110.00%	110.00%
Percentage of voting power of all classes of common stock				10.00%	10.00%
Two Thousand And Twenty One Employee Stock Purchase Plan [Member]
Redeemable Convertible Preferred Stock And Stockholders Equity [Line Items]
Shares grants				880,000
Two Thousand And Twenty One Employee Stock Purchase Plan [Member] | Maximum [Member]
Redeemable Convertible Preferred Stock And Stockholders Equity [Line Items]
Shares grants				15,000,000
Two Thousand And Twenty One Equity Incentive Plan [Member]
Redeemable Convertible Preferred Stock And Stockholders Equity [Line Items]
Shares authorized				6,508,048	0
Weighted average exercise price | $ / shares		$ 1.56
Two Thousand And Thirteen Equity Incentive Plan [Member]
Redeemable Convertible Preferred Stock And Stockholders Equity [Line Items]
Shares authorized				3,886,613	4,594,060
Shares grants				0	132,974
Condition For Conversion Of Redeemable Convertible Preferred Stock Into Common Stock [Member] | Minimum [Member]
Redeemable Convertible Preferred Stock And Stockholders Equity [Line Items]
Net assets | $				$ 250,000,000	$ 250,000,000
Proceeds from initial public offering gross | $				$ 60,000,000	$ 60,000,000
Series A Redeemable Convertible Preferred Stock [Member]
Redeemable Convertible Preferred Stock And Stockholders Equity [Line Items]
Temporary equity dividend per share | $ / shares				$ 0.3243052	$ 0.3243052
Series B Redeemable Convertible Preferred Stock [Member]
Redeemable Convertible Preferred Stock And Stockholders Equity [Line Items]
Temporary equity dividend per share | $ / shares				0.4046443	0.4046443
Series C Redeemable Convertible Preferred Stock [Member]
Redeemable Convertible Preferred Stock And Stockholders Equity [Line Items]
Temporary equity dividend per share | $ / shares				$ 0.4258018	$ 0.4258018
Series C Convertible Preferred Stock [Member]
Redeemable Convertible Preferred Stock And Stockholders Equity [Line Items]
Stock Issued During Period, Shares, Stock Splits			258,805
Series C Convertible Preferred Stock [Member] | Series C Preferred Stock Purchase Agreement [Member]
Redeemable Convertible Preferred Stock And Stockholders Equity [Line Items]
Proceeds from initial public offering gross | $			$ 20,400,000
Stock issued during period shares			3,836,997
Shares Issued, Price Per Share | $ / shares			$ 5.33
Series A Convertible Preferred Stock [Member]
Redeemable Convertible Preferred Stock And Stockholders Equity [Line Items]
Stock Issued During Period, Shares, Stock Splits			2,493,021
Series B Convertible Preferred Stock [Member]
Redeemable Convertible Preferred Stock And Stockholders Equity [Line Items]
Stock Issued During Period, Shares, Stock Splits			916,629
Series A Preferred Stock [Member]
Redeemable Convertible Preferred Stock And Stockholders Equity [Line Items]
Preferred stock, shares outstanding		11,563,819
Series B Preferred Stock [Member]
Redeemable Convertible Preferred Stock And Stockholders Equity [Line Items]
Preferred stock, shares outstanding		10,154,819
Series C Preferred Stock [Member]
Redeemable Convertible Preferred Stock And Stockholders Equity [Line Items]
Preferred stock, shares outstanding		6,734,590
[1]	Historical shares and capital amounts have been retroactively restated for the reverse recapitalization as described in Note 1.

Convertible Preferred Stock a_4

Convertible Preferred Stock and Stockholders' Deficit - Summary of temporary equity (Detail) $ / shares in Units, $ in Thousands	Dec. 31, 2021USD ($)$ / sharesshares
Temporary Equity [Line Items]
Shares Authorized	32,474,428
Shares Outstanding	28,453,228
Liquidation Preference | $	$ 134,087
Series A Redeemable Convertible Preferred Stock [Member]
Temporary Equity [Line Items]
Shares Authorized	14,056,840
Purchase Price Per Share | $ / shares	$ 4.05382
Shares Outstanding	11,563,819
Liquidation Preference | $	$ 46,878
Series B Redeemable Convertible Preferred Stock [Member]
Temporary Equity [Line Items]
Shares Authorized	11,071,448
Purchase Price Per Share | $ / shares	$ 5.05806
Shares Outstanding	10,154,819
Liquidation Preference | $	$ 51,364
Series C Redeemable Convertible Preferred Stock [Member]
Temporary Equity [Line Items]
Shares Authorized	7,346,140
Purchase Price Per Share | $ / shares	$ 5.32253
Shares Outstanding	6,734,590
Liquidation Preference | $	$ 35,845

Convertible Preferred Stock a_5

Convertible Preferred Stock and Stockholders' Deficit - Summary of Company's Stock Option Activity (Detail) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Redeemable Convertible Preferred Stock And Stockholders Equity [Abstract]
Shares Beginning Outstanding	3,887,038
Number of Option Outstanding,Granted	484,512
Exercised	(98,936)	(111,354)
Cancelled	(79,293)
Shares Ending Outstanding	4,193,321	3,887,038
Vested and exercisable Shares	3,076,726
Beginning of Weighted- Average Exercise Price outstanding	$ 1.41
Weighted Average Exercise Price,Granted	10.81
Weighted average exercise price,Exercised	1.09
Weighted average exercise price,Cancelled	6.13
Ending of Weighted- Average Exercise Price outstanding	2.41	$ 1.41
Vested and exercisable	1.43
Weighted- Average Remaining Contractual Term - Outstanding at December 31, 2020	6.6
Granted	9.7
Exercised	4.4
Cancelled	8.3
Weighted- Average Remaining Contractual Term - Outstanding at December 31, 2021	$ 6	$ 6.6
Weighted- Average Remaining Contractual Term,Exercisable	5 days
Aggregate Intrinsic Value - Outstanding at December 31, 2020	$ 3,806
Aggregate Intrinsic Value - Outstanding at December 31, 2021	26,115	$ 3,806
Vested and exercisable at December 31, 2021	$ 21,191

Convertible Preferred Stock a_6

Convertible Preferred Stock and Stockholders' Deficit - Summary of fair value of stock option grants using Black-Scholes option pricing model (Detail)	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected term (in years)	2 years 4 months 24 days
Expected dividend yield	0.00%	0.00%
Risk-free interest rate - Minimum	0.70%	0.30%
Risk-free interest rate - Maximum	1.30%	1.00%
Expected volatility - Minimum	81.00%	87.00%
Expected volatility - Maximum	90.00%	93.00%
Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected term (in years)	6 years 1 month 6 days	6 years 1 month 6 days
Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected term (in years)	5 years 6 months	5 years 3 months 18 days

Convertible Preferred Stock a_7

Convertible Preferred Stock and Stockholders' Deficit - Summary of Common Stock Reserved for Future Issuance (Detail) - shares	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Disclosure Of Common Stock Shares Reserved For Future Issuance Line Items [Line Items]
Unvested Shares Held By Sponsors	300,000	0
Total	21,709,661	32,543,695
Earn Out Shares [Member]
Disclosure Of Common Stock Shares Reserved For Future Issuance Line Items [Line Items]
Earn-Out shares	5,000,000	0
Public Warrants Issued and Outstanding
Disclosure Of Common Stock Shares Reserved For Future Issuance Line Items [Line Items]
Warrants Issued And Outstanding	5,833,333	0
Private Placement Warrants Issued and Outstanding
Disclosure Of Common Stock Shares Reserved For Future Issuance Line Items [Line Items]
Warrants Issued And Outstanding	181,667	0
Redeemable Convertible Preferred Stock [Member]
Disclosure Of Common Stock Shares Reserved For Future Issuance Line Items [Line Items]
Authorized for future stock awards or option grants	0	28,453,228
Stock Options Issued And Outstanding [Member]
Disclosure Of Common Stock Shares Reserved For Future Issuance Line Items [Line Items]
Authorized for future stock awards or option grants	4,193,321	3,887,038
Preferred Stock Warrants Issued And Outstanding [Member]
Disclosure Of Common Stock Shares Reserved For Future Issuance Line Items [Line Items]
Authorized for future stock awards or option grants	0	70,455
Authorized For Future Stock Awards Or Option Grants [Member]
Disclosure Of Common Stock Shares Reserved For Future Issuance Line Items [Line Items]
Authorized for future stock awards or option grants	6,201,340	132,974

Earn-Out Shares - Additional In

Earn-Out Shares - Additional Information (Detail) - USD ($) $ / shares in Units, $ in Thousands	Aug. 25, 2021	Dec. 31, 2021	Dec. 31, 2020
Business Acquisition, Equity Interests Issued or Issuable [Line Items]
Consecutive trading days required for entitlement of common stock		20 days
Trading days required for entitlement of common stock		30 days
Common stock price per share		$ 0.0001	$ 0.0001
Gain on change in fair value of earn-out liability		$ 48,910	$ 0
Common stock, shares issued		40,689,975	1,445,065
Earn Out Shares [Member]
Business Acquisition, Equity Interests Issued or Issuable [Line Items]
Gain on change in fair value of earn-out liability		$ 48,900
Fair value of earn-out shares	13.79	2.74
Fair value of option holder Earn-out Shares	$ 7,900
Share based compensation		$ 7,600
Share based compensation service period	4 months 9 days
Unrecognized compensation expense		$ 300
Unrecognized compensation expense expected to be recognized		1 month 6 days
Estimated fair value of Earn-out Shares		$ 61,000
Earn Out Shares [Member] | Stockholders [Member]
Business Acquisition, Equity Interests Issued or Issuable [Line Items]
Common stock, shares issued	4,425,258	4,426,889
Earn Out Shares [Member] | Option Holders [Member]
Business Acquisition, Equity Interests Issued or Issuable [Line Items]
Common stock, shares issued	574,742	573,111
Effector Therapeutics Inc [Member]
Business Acquisition, Equity Interests Issued or Issuable [Line Items]
Common stock price per share		$ 20
Business Acquisition, Equity Interest Issued or Issuable, Number of Shares		5,000,000

Earn-Out Shares - Summary of Es

Earn-Out Shares - Summary of Estimated Fair Value of Earn-Out Shares (Detail) - Earn Out Shares [Member]	Dec. 31, 2021yr$ / shares	Aug. 25, 2021$ / sharesyr
Common stock price
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Measurement input | $ / shares	8.28	16.98
Expected volatility
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Measurement input	0.650	0.600
Risk-free interest rate
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Measurement input	0.006	0.002
Forecast period (in years)
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Measurement input | yr	1.6	2
Cost of equity
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Measurement input	0.200	0.200

Earn-Out Shares - Summary of Ac

Earn-Out Shares - Summary of Activity for Earn-Out Liability (Detail) - Fair Value, Inputs, Level 3 [Member] - Earn Out Liability [Member] $ in Thousands	4 Months Ended
	Dec. 31, 2021USD ($)
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Fair value, Beginning Balance	$ 61,024
Incremental shares due to option holder forfeitures	16
Change in fair value	(48,910)
Fair value, Ending Balance	$ 12,130

License Agreements - Additional

License Agreements - Additional Information (Details) - USD ($)	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2013	Aug. 31, 2021	Jul. 31, 2021
License Agreement Disclosure [Line Items]
Research and development expense	$ 19,956,000	$ 21,832,000
Regents Of The University Of California [Member]
License Agreement Disclosure [Line Items]
Payment of one time license issuance fees			$ 50,000
Payable In Connection With The Closing Of The Merger Agreement	1,000,000	1,000,000		$ 1,000,000
Research and development expense	15,000	$ 15,000
Amendment To The License Agreement [Member] | Regents Of The University Of California [Member]
License Agreement Disclosure [Line Items]
Payable In Connection With The Closing Of The Merger Agreement					$ 1,000,000
Terminate agreement period for written notice			60 days
Amendment To The License Agreement [Member] | Regents Of The University Of California [Member] | Certain Clinical And Regulatory Milestones [Member]
License Agreement Disclosure [Line Items]
Remaining milestone payments payable	$ 375,000

Research Collaboration and Li_2

Research Collaboration and License Agreement - Additional Information (Detail) - USD ($) $ in Millions	1 Months Ended	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2020
Research Collaboration And License Agreement [Line Items]
Revenues		$ 42
Research and Development Agreement [Member] | Pfizer [Member]
Research Collaboration And License Agreement [Line Items]
Upfront payment received	$ 15
Performance obligation transaction price	27
Received towards delivery of license and reimbursement of research activities		$ 42
Research and Development Agreement [Member] | Pfizer [Member] | Based on License [Member]
Research Collaboration And License Agreement [Line Items]
Performance obligation transaction price	25.6
Research and Development Agreement [Member] | Pfizer [Member] | Based on Research Activities [Member]
Research Collaboration And License Agreement [Line Items]
Performance obligation transaction price	1.4
Research and Development Agreement [Member] | Pfizer [Member] | Early Development and Regulatory Milestones [Member]
Research Collaboration And License Agreement [Line Items]
Milestone payment receivable	80
Research and Development Agreement [Member] | Pfizer [Member] | Non Early Stage Development Milestones [Member] | Non Exercise of Co-Funding And Co-Promotion Option [Member]
Research Collaboration And License Agreement [Line Items]
Milestone payment receivable	165
Research and Development Agreement [Member] | Pfizer [Member] | Non Early Stage Development Milestones [Member] | Exercise of Co-Funding And Co-Promotion Option [Member]
Research Collaboration And License Agreement [Line Items]
Milestone payment receivable	70
Research and Development Agreement [Member] | Pfizer [Member] | Specified Sales Based Milestones [Member]
Research Collaboration And License Agreement [Line Items]
Milestone payment receivable	$ 235

DARPA Grant Revenue - Additiona

DARPA Grant Revenue - Additional Information (Detail) - USD ($) $ in Thousands	1 Months Ended	12 Months Ended
	Apr. 30, 2021	Dec. 31, 2021	Dec. 31, 2020
DARPA Grant Revenue Disclosure [Line Items]
Allowable costs of reimbursable	$ 5,000
Revenues			$ 42,000
Prepaid expenses and other current assets		$ 3,194	1,362
Research and development arrangement maximum reimbursement amount		$ 5,000
Research and development arrangement extended period month year		2022-12
DARPA Grant Revenue [Member]
DARPA Grant Revenue Disclosure [Line Items]
Revenues		$ 1,400	0
Prepaid expenses and other current assets		$ 100	$ 0

Commitments and Contingencies -

Commitments and Contingencies - Schedule of Supplemental Balance Sheet Information Related to Leases (Detail) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Assets:
Operating lease right-of-use assets	$ 166	$ 92
Total right-of-use assets	166	92
Liabilities
Operating lease liabilities, current	44	108
Operating lease liabilities, non-current	126	0
Total operating lease liabilities	$ 170	$ 108

Commitments and Contingencies_2

Commitments and Contingencies - Schedule of Future Minimum Rental Payments for Operating Leases (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Commitments and Contingencies Disclosure [Abstract]
2022	$ 55
2023	73
2024	62
Total remaining lease payments	190
Less: imputed interest	(20)
Total operating lease liabilities	170	$ 108
Less: current portion	(44)
Long-term operating lease liabilities	$ 126	$ 0
Weighted-average remaining lease term (in years)	2 years 9 months 18 days
Weighted-average discount rate	8.00%

Commitments and Contingencies_3

Commitments and Contingencies - Additional Information (Detail) - USD ($)	1 Months Ended	12 Months Ended
	Sep. 30, 2021	Dec. 31, 2021	Dec. 31, 2020
Commitments [Line Items]
Lease term	3 years
Annual rent payment	$ 70,200
Solana Beach California [Member] | Office Space [Member]
Commitments [Line Items]
Operating lease annual increase to base rent		3.00%
Rent under operating lease expense		$ 16,400
Operating Sublease For Office Space [Member] | California
Commitments [Line Items]
Operating lease, payments		100,000	$ 700,000
Rent under operating lease expense		$ 100,000	$ 600,000

Income Taxes - Summary of Compa

Income Taxes - Summary of Company's Net Deferred Tax Assets (Detail) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Deferred tax assets:
Net operating loss carryforwards	$ 36,898	$ 29,829
Intangibles	3,565	3,875
Accrued compensation	1,284	325
Credits	7,107	6,252
Fixed assets	6	40
Other, net	74	96
Right-of-use liability	36	23
Deferred tax assets	48,970	40,440
Deferred tax liabilities:
Right-of-use asset	(35)	(19)
Deferred tax liabilities	(35)	(19)
Net deferred tax assets	48,935	40,421
Valuation allowance	(48,935)	(40,421)
Net deferred tax assets	$ 0	$ 0

Income Taxes - Summary of Recon

Income Taxes - Summary of Reconciliation of the Income Tax Computed at the Federal Statutory Tax Rate to the Expense (Benefit) for Income Taxes (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Effective Income Tax Rate Reconciliation, Amount [Abstract]
Tax at statutory rate	$ 3,318	$ 3,058
State income taxes, net of federal benefits	(1,853)	292
Change in valuation allowance	8,515	808
Uncertain tax positions	569	474
Gain on change in fair value of earn-out liability	(10,271)	0
Permanent differences and other	636	47
Capitalized R&D	510	(3,836)
Credits	(1,424)	(492)
Income tax expense	$ 0	$ 351

Income Taxes - Summary of Rec_2

Income Taxes - Summary of Reconciliation of the Beginning and Ending Amount of Unrecognized Tax Benefit (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Balance at beginning of the year	$ 7,623	$ 7,068
Additions/(reductions) for tax positions - prior year	0	0
Increase related to current year positions	612	555
Balance at the end of the year	$ 8,235	$ 7,623

Income Taxes - Additional Infor

Income Taxes - Additional Information (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Current income tax expense (benefit)	$ 0	$ 400
Deferred tax assets, valuation allowance	48,935	40,421
Operating loss carry forwards	1,800	100
Deferred tax assets, operating loss carry forwards	36,898	29,829
Deferred tax assets, tax credit carry forwards	$ 7,107	$ 6,252
Percentage of elimination of NOL limitation for tax period	80.00%	100.00%
Unrecognized tax benefits, income tax penalties and interest expense	$ 0	$ 0
Balance of unrecognized tax benefits	$ 6,800
Coronavirus aid relief and economic security act period in which net operating loss to be carried	5 years
Research Tax Credit Carryforward [Member]
Deferred tax assets, operating loss carry forwards		600
Deferred tax assets, tax credit carry forwards		$ 100
Tax credit carry forward, amount	$ 3,800
Research Tax Credit Carryforward [Member] | 2034 [Member]
Operating loss carry forwards	63,200
Orphan Drug Tax Credit Carryforwards [Member]
Tax credit carry forward, amount	$ 2,200
Tax credit carry forward expiration period	2037 years
Federal Tax Authority [Member]
Tax credit carry forward, amount	$ 8,500
Federal Tax Authority [Member] | Indefinitely Period [Member]
Operating loss carry forwards	87,500
Federal Tax Authority [Member] | 2034 [Member]
Operating loss carry forwards	$ 166,000

Subsequent Events - Additional

Subsequent Events - Additional Information (Detail) - USD ($) $ in Thousands		Feb. 22, 2022	Jan. 24, 2022	Dec. 31, 2021	Feb. 28, 2022	Dec. 31, 2020
Subsequent Event [Line Items]
Initial purchase of shares of common stock	[1]					$ 108
Loan and Security Agreement [Member] | Oxford Finance LLC [Member] | Debt Instrument, Term Loan A [Member]
Subsequent Event [Line Items]
Cut off date before which the interest on the term loan shall be paid				Mar. 1, 2024
Long term debt maturity date				Mar. 18, 2026
Loan and Security Agreement [Member] | Oxford Finance LLC [Member] | Debt Instrument, Term Loan B. [Member]
Subsequent Event [Line Items]
Number of days within which a portion of term loan will be available subject to achievement of milestone					45 days
Subsequent Event [Member] | Loan and Security Agreement [Member] | Oxford Finance LLC [Member]
Subsequent Event [Line Items]
Long term debt maturity date					Feb. 1, 2027
Subsequent Event [Member] | Loan and Security Agreement [Member] | Oxford Finance LLC [Member] | Debt Instrument, Term Loan A [Member]
Subsequent Event [Line Items]
Cut off date before which the interest on the term loan shall be paid		May 1, 2023
Long term debt maturity date		Feb. 1, 2027
Subsequent Event [Member] | Loan and Security Agreement [Member] | Oxford Finance LLC [Member] | Debt Instrument, Term Loan B. [Member]
Subsequent Event [Line Items]
Cut off date before which the interest on the term loan shall be paid		Mar. 1, 2024			Mar. 1, 2024
Cut off date in which debt is available		Jan. 1, 2023			Jan. 1, 2023
Line of Credit Facility, Initiation Date		Jun. 30, 2023			Jun. 30, 2023
Number of days within which a portion of term loan will be available subject to achievement of milestone		45 days
Extended cut off date before which the interest on term loan shall be paid		Mar. 1, 2025
Subsequent Event [Member] | Equity Purchase Agreement [Member]
Subsequent Event [Line Items]
Stock issued during period shares			557,610
Sale of common stock over the term of purchase agreement			$ 50,000
Term of purchase agreement			36 months
Initial purchase of shares of common stock			$ 3,000
Number of shares of common stock issued as a commitment fee as per agreement			142,939
[1]	Historical shares and capital amounts have been retroactively restated for the reverse recapitalization as described in Note 1.