0001576885-23-000017 | 10-K | XBRL Viewer | Acumen Pharmaceuticals INC

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Cover Page - USD ($) $ in Millions	12 Months Ended
Cover Page - USD ($) $ in Millions	Dec. 31, 2022	Mar. 22, 2023	Jun. 30, 2022
Cover [Abstract]
Document Type	10-K
Document Annual Report	true
Document Period End Date	Dec. 31, 2022
Current Fiscal Year End Date	--12-31
Document Transition Report	false
Entity File Number	001-40551
Entity Registrant Name	Acumen Pharmaceuticals, Inc.
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	36-4108129
Entity Address, Address Line One	427 Park St.
Entity Address, City or Town	Charlottesville
Entity Address, State or Province	VA
Entity Address, Postal Zip Code	22902
City Area Code	434
Local Phone Number	297-1000
Title of 12(b) Security	Common Stock, $0.0001 par value per share
Trading Symbol	ABOS
Security Exchange Name	NASDAQ
Entity Well-known Seasoned Issuer	No
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Non-accelerated Filer
Entity Small Business	true
Entity Emerging Growth Company	true
Entity Ex Transition Period	false
ICFR Auditor Attestation Flag	false
Entity Shell Company	false
Entity Public Float			$ 135.4
Entity Common Stock, Shares Outstanding		41,025,062
Documents Incorporated by Reference	Portions of the registrant’s definitive proxy statement relating to its 2023 annual meeting of the shareholders, or the 2023 Proxy Statement, are incorporated by reference into Part III of this Annual Report on Form 10-K where indicated. The 2023 Proxy Statement will be filed with the U.S. Securities and Exchange Commission within 120 days after the end of the fiscal year to which this report relates.
Entity Central Index Key	0001576885
Document Fiscal Year Focus	2022
Document Fiscal Period Focus	FY
Amendment Flag	false

Audit Information	12 Months Ended
Audit Information	Dec. 31, 2022
Audit Information [Abstract]
Auditor Name	Ernst & Young LLP
Auditor Firm ID	42
Auditor Location	Tysons, Virginia

Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Current assets
Cash and cash equivalents	$ 130,101	$ 122,162
Marketable securities, short-term	47,504	72,075
Prepaid expenses and other current assets	2,724	4,424
Total current assets	180,329	198,661
Marketable securities, long-term	15,837	31,619
Property and equipment, net	165	36
Right-of-use asset	105	0
Other assets	151	14
Total assets	196,587	230,330
Current liabilities
Accounts payable	1,640	1,088
Accrued clinical trial expenses	2,717	147
Accrued expenses and other current liabilities	3,350	3,912
Operating lease liability, current portion	105	0
Total current liabilities	7,812	5,147
Total liabilities	7,812	5,147
Commitments and contingencies (Note 11)
Stockholders’ equity
Preferred stock, $0.0001 par value; 10,000,000 shares authorized and no shares issued and outstanding as of December 31, 2022 and 2021	0	0
Common stock, $0.0001 par value; 300,000,000 shares authorized and 41,025,062 and 40,473,270 shares issued and outstanding as of December 31, 2022 and 2021, respectively	4	4
Additional paid-in capital	359,949	352,981
Accumulated deficit	(170,427)	(127,571)
Accumulated other comprehensive loss	(751)	(231)
Total stockholders’ equity	188,775	225,183
Total liabilities and stockholders’ equity	$ 196,587	$ 230,330

Balance Sheets (Parenthetical) - $ / shares	Dec. 31, 2022	Dec. 31, 2021
Statement of Financial Position [Abstract]
Preferred stock, par value (in dollars per share)	$ 0.0001	$ 0.0001
Preferred stock, shares authorized (in shares)	10,000,000	10,000,000
Preferred Stock, shares issued (in shares)	0	0
Preferred Stock, shares outstanding (in shares)	0	0
Common stock, par value (in dollars per share)	$ 0.0001	$ 0.0001
Common stock, shares authorized (in shares)	300,000,000	300,000,000
Common stock, shares issued (in shares)	41,025,062	40,473,270
Common stock, shares outstanding (in shares)	41,025,062	40,473,270

Statements of Operations and Comprehensive Loss - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Operating expenses
Research and development	$ 32,361	$ 12,305
General and administrative	12,876	7,279
Total operating expenses	45,237	19,584
Loss from operations	(45,237)	(19,584)
Other income (expense)
Interest income, net	2,392	84
Other income (expense), net	(11)	51
Change in fair value of preferred stock tranche rights liability and preferred stock warrant liability	0	(81,157)
Total other income (expense)	2,381	(81,022)
Net loss	(42,856)	(100,606)
Other comprehensive loss
Unrealized loss on marketable securities	(520)	(231)
Comprehensive loss	$ (43,376)	$ (100,837)
Net loss per common share, basic (in dollars per share)	$ (1.06)	$ (5.02)
Net loss per common share, diluted (in dollars per share)	$ (1.06)	$ (5.02)
Weighted-average shares outstanding, basic (in shares)	40,601,936	20,057,534
Weighted-average shares outstanding diluted (in shares)	40,601,936	20,057,534

Statements of Changes in Convertible Preferred Stock and Stockholders' Equity (Deficit) - USD ($) $ in Thousands	Total	Common Stock	Additional Paid-in Capital	Accumulated Deficit	Accumulated Other Comprehensive Loss	Series A Convertible Preferred Stock	Series A-1 Convertible Preferred Stock	Series B Convertible Preferred Stock
Beginning balance (in shares) at Dec. 31, 2020						477,297	7,537,879	11,862,043
Beginning balance at Dec. 31, 2020						$ 1,067	$ 16,333	$ 39,253
Increase (Decrease) in Temporary Equity [Roll Forward]
Issuance of milestone shares for cash, net of issuance costs (in shares)								7,908,027
Issuance of milestone shares for cash, net of issuance costs								$ 30,031
Exercise of preferred stock warrant (in shares)							447,426
Exercise of preferred stock warrant							$ 1,250
Reclassification of preferred stock tranche rights liability upon issuance of milestone shares	$ 81,190							$ 81,190
Reclassification of warrant liability upon exercise of preferred stock warrant	5,380						$ 5,380
Conversion of convertible preferred stock into common stock upon initial public offering (in shares)						(477,297)	(7,985,305)	(19,770,070)
Conversion of convertible preferred stock into common stock upon initial public offering						$ (1,067)	$ (22,963)	$ (150,474)
Ending balance at Dec. 31, 2021						$ 0	$ 0	$ 0
Ending balance (in shares) at Dec. 31, 2021						0	0	0
Beginning balance (in shares) at Dec. 31, 2020		419,124
Beginning balance at Dec. 31, 2020	(18,591)	$ 0	$ 8,374	$ (26,965)	$ 0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Exercise of common stock warrants (in shares)		137,446
Exercise of common stock warrants	614		614
Conversion of convertible preferred stock into common stock upon initial public offering (in shares)		28,232,672
Conversion of convertible preferred stock into common stock upon initial public offering	174,504	$ 3	174,501
Issuance of common stock for cash, net of issuance costs (in shares)		11,499,998
Issuance of common stock for cash, net of issuance costs	168,556	$ 1	168,555
Cashless exercise of common stock warrants (in shares)		178,847
Stock options exercised (in shares)		5,183
Stock options exercised	15		15
Unrealized loss on marketable securities	(231)				(231)
Stock-based compensation	922		922
Net loss	$ (100,606)			(100,606)
Ending balance (in shares) at Dec. 31, 2021	40,473,270	40,473,270
Ending balance at Dec. 31, 2021	$ 225,183	$ 4	352,981	(127,571)	(231)
Increase (Decrease) in Temporary Equity [Roll Forward]
Reclassification of preferred stock tranche rights liability upon issuance of milestone shares	0
Reclassification of warrant liability upon exercise of preferred stock warrant	0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock for cash, net of issuance costs (in shares)		422,160
Issuance of common stock for cash, net of issuance costs	$ 3,792		3,792
Cashless exercise of common stock warrants (in shares)		4,746
Stock options exercised (in shares)	131,626	124,886
Stock options exercised	$ 115		115
Unrealized loss on marketable securities	(520)				(520)
Stock-based compensation	3,061		3,061
Net loss	$ (42,856)			(42,856)
Ending balance (in shares) at Dec. 31, 2022	41,025,062	41,025,062
Ending balance at Dec. 31, 2022	$ 188,775	$ 4	$ 359,949	$ (170,427)	$ (751)

Statements of Changes in Convertible Preferred Stock and Stockholders' Equity (Deficit) (Parenthetical) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Common Stock
Stock issuance costs	$ 412	$ 15,445
Series B Convertible Preferred Stock
Stock issuance costs		$ 16

Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
Statements of Cash Flows - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Cash flows from operating activities
Net loss	$ (42,856)	$ (100,606)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation	32	4
Change in fair value of preferred stock tranche rights liability and preferred stock warrant liability	0	81,157
Stock-based compensation expense	3,061	922
Amortization of premiums and accretion of discounts on marketable securities, net	487	155
Amortization of right-of-use asset	137	0
Other non-cash expense	0	109
Changes in operating assets and liabilities:
Prepaid expenses and other current assets	1,700	(3,881)
Other assets	(137)	(14)
Accounts payable	552	557
Accrued clinical trial expenses	2,570	147
Operating lease liability	(137)	0
Accrued expenses and other current liabilities	(562)	3,489
Net cash used in operating activities	(35,153)	(17,961)
Cash flows from investing activities
Purchases of marketable securities	(41,514)	(104,080)
Proceeds from maturities and sales of marketable securities	80,860	0
Purchases of property and equipment	(161)	(40)
Net cash provided by (used in) investing activities	39,185	(104,120)
Cash flows from financing activities
Proceeds from issuance of common stock, net of issuance costs	3,792	168,556
Proceeds from exercise of stock options	115	15
Proceeds from issuance of Series B milestone shares, net of issuance costs	0	30,031
Proceeds from exercise of Series A-1 warrant	0	1,250
Proceeds from exercise of common stock warrants	0	614
Net cash provided by financing activities	3,907	200,466
Net change in cash and cash equivalents	7,939	78,385
Cash and cash equivalents at the beginning of the period	122,162	43,777
Cash and cash equivalents at the end of the period	130,101	122,162
Supplemental disclosure of cash flow information
Cash paid for income taxes	0	0
Cash paid for interest	0	0
Supplemental disclosure of noncash financing activities
Right-of-use assets obtained in exchange for operating lease liabilities	242	0
Conversion of convertible preferred stock into common stock upon IPO	0	174,504
Reclassification of preferred stock tranche rights liability upon share issuance	0	81,190
Reclassification of warrant liability upon exercise of preferred stock warrant	$ 0	$ 5,380

Description of Organization and Business Operations	12 Months Ended
Description of Organization and Business Operations	Dec. 31, 2022
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Description of Organization and Business Operations	DESCRIPTION OF ORGANIZATION AND BUSINESS OPERATIONS Acumen Pharmaceuticals, Inc. (“Acumen” or the “Company”) was incorporated in 1996 in the state of Delaware. Acumen is a clinical-stage biopharmaceutical company developing a novel disease-modifying approach to target what the Company believes to be a key underlying cause of Alzheimer’s disease (“AD”). Alzheimer’s disease is a progressive neurodegenerative disease of the brain that leads to loss of memory and cognitive functions and ultimately results in death. The Company’s scientific founders pioneered research on soluble amyloid-beta oligomers (“AßOs”), which are globular assemblies of the amyloid-beta (“Aß”) peptide that are distinct from Aß monomers and amyloid plaques. Based on decades of research and supporting evidence, AßOs have gained increasing scientific acceptance as a primary toxin involved in the initiation and propagation of AD pathology. The Company is currently focused on advancing a targeted immunotherapy drug candidate, ACU193, through clinical proof of mechanism trials in early AD patients. ACU193 is a recombinant humanized immunoglobin gamma 2 (“IgG2”) monoclonal antibody (“mAb”) that was designed to selectively target AßOs, has demonstrated functional and protective effects in in vitro assays, and has demonstrated in vivo safety and pharmacologic activity in multiple animal species, including transgenic models for AD. The Company is subject to the uncertainty of whether its intellectual property will develop into successful commercial products. June 2021 Reverse Stock Split The Company’s Board of Directors (“Board”) approved a reverse split of shares of the Company’s common stock and convertible preferred stock on a 1-for-1.49 basis (the “June 2021 Reverse Stock Split”), which was effected on June 23, 2021. The par value and the number of authorized shares of the convertible preferred stock and common stock were not adjusted in connection with the June 2021 Reverse Stock Split. All references to common stock, convertible preferred stock, warrants to purchase common stock, warrants to purchase convertible preferred stock, options to purchase common stock, share data, per share data and related information contained in the financial statements have been retrospectively adjusted to reflect the effect of the June 2021 Reverse Stock Split for all periods presented. No fractional shares of the Company’s common stock were issued in connection with the June 2021 Reverse Stock Split. Any fractional share resulting from the June 2021 Reverse Stock Split was rounded down to the nearest whole share, and any stockholder entitled to a fractional share as a result of the June 2021 Reverse Stock Split received a cash payment in lieu of receiving fractional shares. Initial Public Offering On July 6, 2021, the Company issued 9,999,999 shares of common stock in an initial public offering (“IPO”), and on July 8, 2021, the Company issued an additional 1,499,999 shares of common stock that were purchased by the underwriters pursuant to the underwriters’ option to purchase additional shares at the public offering price less underwriting discounts and commissions. The price to the public for each share was $16.00. The aggregate net proceeds from the Company’s IPO, after underwriting discounts and commissions and other offering expenses of $15.4 million, were $168.6 million. On July 6, 2021, in connection with the closing of the IPO, 477,297 shares of Series A, 7,985,305 shares of Series A-1, and 19,770,070 shares of Series B convertible preferred stock, respectively, automatically converted into an equal number of shares of common stock. Warrants to purchase shares of common stock were automatically net exercised for the purchase of an aggregate of 178,847 shares of common stock. As a result of the IPO, the underwriters’ exercise of their option, the conversions of the Series A, A-1 and B convertible preferred stock, and the exercise of the warrants, the Company’s total number of outstanding common shares increased by 39,911,517 immediately following the closing of the IPO. Liquidity and Capital Resources The Company has incurred operating losses since inception and expects to continue to incur significant operating losses for the foreseeable future and may never become profitable. As of December 31, 2022 and 2021, the Company had an accumulated deficit of $170.4 million and $127.6 million, respectively, and working capital of $172.5 million and $193.5 million, respectively. Management believes that the Company has sufficient cash to continue operating activities for beyond 12 months from issuance of these financial statements. In October 2022, the Company issued 422,160 shares of common stock for net proceeds of $3.8 million, at a weighted average price of $10.06 per share. See additional discussion in Note 8. Future capital requirements will depend upon many factors, including the timing and extent of spending on research and development and market acceptance of the Company’s products. The Company may need to obtain additional financing to complete clinical trials and launch and commercialize any product candidates for which it receives regulatory approval. Until such time, if ever, the Company can generate revenue sufficient to achieve profitability, the Company expects to finance its operations through a combination of equity offerings, debt financings, collaborations, strategic alliances and licensing arrangements. There can be no assurance that such financing will be available on terms acceptable to the Company, or at all. To the extent that the Company raises additional capital through the sale of equity or convertible debt securities, the ownership interest of its stockholders will be diluted, and the terms of these securities may include liquidation of other preferences that adversely affect the rights of common stockholders. Debt financing and preferred equity financing, if available, may involve agreements that include covenants limiting or restricting the Company’s ability to take specific actions, such as incurring additional debt, making acquisitions or capital expenditures or declaring dividends. If the Company is unable to maintain sufficient financial resources, its business, financial condition and results of operations will be materially and adversely affected. The Company may be required to delay, limit, reduce or terminate its product discovery and development activities or future commercialization efforts. The Company initiated a Phase 1 clinical trial of ACU193 in the second quarter of 2021, which the Company named “INTERCEPT-AD.” This trial enrolled patients with mild dementia or mild cognitive impairment (“MCI”), due to AD, conditions referred to as “early AD.” INTERCEPT-AD is a U.S.-based, multi-center, randomized, double-blind, placebo-controlled clinical trial with overlapping single ascending dose and multiple ascending dose cohorts involving a total of approximately 65 patients with early AD.

Basis of Presentation, Summary of Significant Accounting Policies and Recent Accounting Pronouncements	12 Months Ended
	Dec. 31, 2022
Accounting Policies [Abstract]
Basis of Presentation, Summary of Significant Accounting Policies and Recent Accounting Pronouncements	BASIS OF PRESENTATION, SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES AND RECENT ACCOUNTING PRONOUNCEMENTS Basis of Presentation The accompanying financial statements of the Company have been prepared in accordance with accounting principles generally accepted in the United States of America (“U.S. GAAP”) and pursuant to the rules and regulations of the U.S. Securities and Exchange Commission (“SEC”). In the opinion of management, all adjustments (consisting of normal recurring adjustments) have been made that are necessary to present fairly the Company’s financial position, and the results of its operations and its cash flows. Emerging Growth Company 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 impact of recently issued standards that are not yet effective will not have a material impact on the Company’s financial statements upon adoption. Under the Jumpstart Our Business Startups Act of 2012, as amended, the Company meets the definition of an emerging growth company and has elected the extended transition period for complying with new or revised accounting standards, which delays the adoption of these accounting standards until they would apply to private companies. Use of Estimates The preparation of financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements, as well as the reported amounts of expenses during the reporting periods. These estimates and assumptions are based on the Company’s historical experience, and on various other factors that management believes are reasonable under the circumstances, the results of which form the basis for making judgments about the carrying values of assets and liabilities and the recording of expenses that are not readily apparent from other sources. Actual results may differ from these estimates under different assumptions or conditions. To the extent there are material differences between the estimates and actual results, the Company’s future results of operations will be affected. Reclassifications Certain prior year amounts have been reclassified for consistency with the current period presentation. Accrued clinical trial expenses are presented as a separate line on the balance sheets and statements of cash flows, whereas these accrued expenses were previously included in accrued expenses and other current liabilities. These reclassifications had no effect on the reported results of operations. 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. The Company’s cash equivalents consist of funds held in several money market accounts. The Company had $129.1 million and $121.2 million in cash equivalents as of December 31, 2022 and 2021, respectively. Marketable Securities The Company’s marketable securities portfolio consists primarily of investments in money market funds, commercial paper, asset-backed securities, U.S. treasury securities and short-term highly liquid, high credit quality corporate debt securities. The Company considers its marketable securities to be available-for-sale. Available-for-sale securities are classified as cash equivalents, or as short-term or long-term marketable securities based on the maturity date at time of purchase and their availability to meet current operating requirements. Available-for-sale securities that mature in three months or less from the date of purchase are classified as cash equivalents. Available-for-sale securities, excluding cash equivalents, that mature in one year or less are classified as short-term marketable securities and those that mature in more than one year are classified as long-term. Securities that are classified as available-for-sale are measured at fair value; see “Fair Value of Financial Instruments” below. Any premium arising at purchase is amortized to the earliest call date and any discount arising at purchase is accreted to maturity. Amortization and accretion of premiums and discounts are recorded along with interest income on investments in interest income, net in the statements of operations and comprehensive loss. Unrealized gains and losses are excluded from earnings and are reported as a component of other comprehensive income. The Company periodically evaluates whether declines in fair values of its available-for-sale securities below their book value are other-than-temporary. This evaluation consists of several qualitative and quantitative factors regarding the severity and duration of the unrealized loss, as well as the Company’s ability and intent to hold the available-for-sale security until a forecasted recovery occurs. The Company does not generally intend to sell its available-for-sale securities; however, the Company assesses whether it is more likely than not that it will be required to sell any security before recovery of its amortized cost basis. Realized gains and losses and declines in fair value judged to be other-than-temporary on available-for-sale securities will be included in other expense, net. The cost of investments sold will be calculated using the specific-identification method. The Company did not record any other-than-temporary impairments related to available-for-sale securities for the years ended December 31, 2022 or 2021. Concentrations of Credit Risk Financial instruments that potentially subject the Company to significant concentration of credit risk consist primarily of cash, cash equivalents and marketable securities. The Company maintains deposits in financial institutions in excess of government insured limits. Management believes that the Company is not exposed to significant credit risk as the Company’s cash and cash equivalents are held at financial institutions that management believes to be of high credit quality. The Company has not experienced any losses due to credit risk on such accounts during any of the periods presented. Fair Value of Financial Instruments The Company’s financial assets and liabilities are accounted for in accordance with Accounting Standards Codification (“ASC”) 820, Fair Value Measurements and Disclosures, which defines fair value as the exchange price that would be received for an asset or paid to transfer a liability (an exit price) in the principal or most advantageous market for the asset or liability in an orderly transaction between market participants on the measurement date. The fair value hierarchy requires an entity to maximize the use of observable inputs when measuring fair value and classifies those inputs into three levels: Level 1 — Observable inputs, such as quoted prices in active markets for identical assets or liabilities. Level 2 — Inputs other than Level 1 inputs that are either directly or indirectly observable, such as quoted prices for similar assets or liabilities; quoted prices in markets that are not active; or other inputs that are observable or can be corroborated by observable market data for substantially the full term of the instrument’s anticipated life. Level 3 — Unobservable inputs in which there is little or no market data, which require the reporting entity to develop its own assumptions. To the extent the valuation is based on models or inputs that are less observable or unobservable in the market, the determination of fair values requires more judgement. Accordingly, the degree of judgement exercised by management in determining fair value is greatest for instruments categorized as Level 3. A financial instrument’s level within the fair value hierarchy is based on the lowest level of any input that is significant to the fair value measurement. The carrying values reported in the Company’s balance sheets for cash (excluding cash equivalents which are recorded at fair value on a recurring basis), accounts payable and accrued expenses are reasonable estimates of their fair values due to the short-term nature of these items. Property and Equipment Property and equipment consists primarily of computer equipment and furniture and fixtures and is stated at cost and depreciated using the straight-line method over the estimated useful lives of the assets, which is generally three years for computer-related assets and five years for furniture. Leases Effective as of January 1, 2022, the Company accounts for its leases under ASC 842, Leases. Under this guidance, arrangements meeting the definition of a lease are classified as operating or financing leases and are recorded on the balance sheet as both a right-of-use asset and a lease liability, calculated by discounting fixed lease payments over the lease term at the rate implicit in the lease or the Company’s incremental borrowing rate. Lease liabilities are increased by interest and reduced by payments each period, and right-of-use assets are amortized over the lease term. For operating leases, interest on the lease liability and the amortization of the right-of-use asset results in straight-line rent expense over the lease term. Variable lease expenses are recorded when incurred and not included in the measurement of right-of-use assets and lease liabilities. ASC 842 provides practical expedients for an entity’s ongoing accounting. In calculating right-of-use assets and lease liabilities, the Company has elected to combine lease and non-lease components. Additionally, the Company has elected to apply the practical expedient related to short-term leases (i.e., leases having initial terms of 12 months or less at commencement date) as an accounting policy election. For short-term leases, the Company will not recognize a right-of-use asset or lease liability, but instead will recognize lease payments as an expense on a straight-line basis over the lease term. Prior to the adoption of ASC 842 on January 1, 2022, the Company accounted for its leases under ASC 840, Leases. Convertible Preferred Stock The Company recorded shares of convertible preferred stock at their respective fair values on the dates of issuance, net of issuance costs. The Company applied the guidance in ASC 480-10-S99-3A, SEC Staff Announcement: Classification and Measurement of Redeemable Securities, and therefore classified the Series A, Series A-1 and Series B convertible preferred stock as mezzanine equity. The convertible preferred stock was recorded outside of stockholders’ deficit because, in the event of certain deemed liquidation events considered not solely within the Company’s control, such as a merger, acquisition and sale of all or substantially all of the Company’s assets, the convertible preferred stock would have become redeemable at the option of the holders. In the event of a change of control of the Company, proceeds received from the sale of such shares would have been distributed in accordance with the corresponding liquidation preferences. The Company did not adjust the carrying values of the convertible preferred stock to the deemed liquidation values of such shares since a liquidation event was not probable at any of the reporting dates. As mentioned above in Note 1, in connection with the closing of the IPO, all of the outstanding shares of Series A, Series A-1 and Series B convertible preferred stock automatically converted into an equal number of shares of common stock on July 6, 2021. Preferred Stock Tranche Rights Liability The Company determined that its obligation to issue, and the Company’s investors’ right to purchase, additional shares of Series B convertible preferred stock pursuant to a subsequent closing, (deemed the “Milestone Closing” in Note 7) represented a freestanding financial instrument (the “tranche liability”), as it was legally detachable and separately exercisable from the initial closing of the Series B convertible preferred stock. The tranche liability was initially recorded at fair value. The proceeds from the sale of the convertible preferred stock were first allocated to the fair value of the tranche liability with the remaining proceeds from the sale of the convertible preferred stock allocated to the Series B convertible preferred stock. The tranche liability was remeasured at each reporting period and upon the exercise of the obligation, with gains and losses arising from subsequent changes in its fair value recognized in other income and expense in the statements of operations and comprehensive loss. The Milestone Closing occurred on June 17, 2021, and as a result, the remaining value of the tranche liability was reclassified to convertible preferred stock on the balance sheet. Preferred Stock Warrant Liability The Company accounted for the warrant to purchase Series A-1 convertible preferred stock as a liability as this warrant was a freestanding financial instrument that required the Company to transfer assets upon exercise. The warrant liability was initially recorded at fair value. The warrant liability was remeasured at each reporting period and upon the exercise of the applicable warrant, with gains and losses arising from subsequent changes in its fair value recognized in other income and expense in the statements of operations and comprehensive loss. The warrant was exercised on June 22, 2021, and the remaining value of the warrant liability was reclassified to convertible preferred stock on the balance sheet. There were no preferred stock warrants outstanding as of December 31, 2022. Common Stock Warrants The Company assesses whether warrants issued require accounting as derivatives. The Company determined that its common stock warrants were (1) indexed to the Company’s own stock and (2) classified in stockholders’ equity in accordance with FASB ASC Topic 815, Derivatives and Hedging. As such, the Company concluded the warrants met the scope exception for determining whether the instruments require accounting as derivatives and should be classified in stockholders’ equity. In June 2021, several holders of warrants to purchase the Company’s common stock exercised their warrants and purchased a total of 137,446 shares of common stock at an exercise price of $4.47. On July 6, 2021, in connection with the closing of the Company’s IPO, the Company issued 178,847 shares of common stock in exchange for the 248,247 outstanding common stock warrants at an exercise price of $4.47 and there were no common stock warrants outstanding following this issuance. Research and Development Expenses Research and development expenses primarily consist of consultants and materials, biologic storage, salaries and other personnel-related expenses related to research and development activities and are expensed as incurred. Payments for these activities are based on the terms of the individual agreements, which may differ from the pattern of costs incurred, and are reflected on the balance sheets as prepaid or accrued expenses. The Company records accruals for estimated ongoing research costs. When evaluating the adequacy of the accrued liabilities, the Company analyzes progress of the studies, including the phase or completion of events, invoices received and contracted costs. Clinical trial costs are a significant component of research and development expenses and include costs associated with third-party contractors. The Company accrues and expenses costs for clinical trial activities performed by third parties based upon the work completed to date for each clinical trial in accordance with established agreements. The Company determines its costs through discussions with internal clinical stakeholders and outside service providers as to the progress or stage of completion of clinical trials or services and the contracted fee to be paid for such services. In the event advance payments are made to an outside service provider, the payments are recorded within prepaid expenses and other current assets on the Balance Sheet and subsequently recognized as research and development expense in the Statement of Operations when the associated services have been performed. As actual costs become known, the Company adjusts its estimates, liabilities and assets. Inputs used in the determination of estimates discussed above may vary from actual, which will result in adjustments to research and development expense in future periods. Stock-based Compensation The Company expenses stock-based compensation to employees, non-employees and board members over the requisite service period based on the estimated grant date fair value of the awards and actual forfeitures. The Company estimates the fair value of stock option grants using the Black-Scholes option pricing model, which requires the use of a number of complex assumptions including the fair value of the common stock, expected volatility, risk-free interest rate, expected dividends, and the expected term of the option. The assumptions used in calculating the fair value of stock-based awards represent management’s best estimates and involve inherent uncertainties and the application of management’s judgment. Stock-based awards with graded-vesting schedules are recognized on a straight-line basis over the requisite service period for each separately vesting portion of the award. All stock-based compensation costs are recorded in research and development expense or general and administrative expense in the statements of operations and comprehensive loss based upon the respective employee’s or non-employee’s roles within the Company. Forfeitures are recorded as they occur. See also Note 9 below. Income Taxes Income taxes are recorded in accordance with ASC 740, Income Taxes (“ASC 740”), which provides for deferred taxes using an asset and liability approach. The Company recognizes deferred tax assets and liabilities for the expected future tax consequences of events that have been included in the financial statements or tax returns. Deferred tax assets and liabilities are determined based on the difference between the financial statement and tax bases of assets and liabilities using enacted tax rates in effect for the year in which the differences are expected to reverse, and net operating loss (“NOL”) carryforwards and research and development (“R&D”) tax credit carryforwards. Valuation allowances are provided if, based upon the weight of available evidence, it is more likely than not that some or all of the deferred tax assets will not be realized. The Company has recorded a full valuation allowance to reduce its net deferred income tax assets to zero. In the event the Company were to determine that it would be able to realize some or all of its deferred income tax assets in the future, an adjustment to the deferred income tax asset valuation allowance would increase income in the period such determination was made. The Company accounts for uncertain tax positions in accordance with the provisions of ASC 740. When uncertain tax positions exist, the Company recognizes the tax benefit of tax positions to the extent that the benefit would more likely than not be realized assuming examination by the taxing authority. The determination as to whether the tax benefit will more likely than not be realized is based upon the technical merits of the tax position as well as consideration of the available facts and circumstances. The Company has not recorded any liabilities related to uncertain tax positions as of December 31, 2022 and 2021. The Company’s policy is to record interest and penalties, if any, as part of income tax benefit. No interest or penalties were recorded during the years ended December 31, 2022 and 2021. Net Loss Per Share of Common Stock Basic net loss per share of common stock is calculated using the two-class method under which earnings are allocated to both common shares and participating securities based on their participation rights. Net loss attributable to common stockholders was not allocated to the convertible preferred stock as the holders of the convertible preferred stock did not have a contractual obligation to share in any losses. Basic net loss per share is calculated by dividing the net loss attributable to common shares by the weighted-average number of shares of common stock outstanding during the period. Diluted net loss per share of common stock is computed by dividing the net loss using the weighted-average number of common shares and, if dilutive, potential common shares outstanding during the period. For the year ended December 31, 2022, potential common shares consisted of stock options. For the year ended December 31, 2021, potential common shares consisted of stock options and warrants to purchase common stock (using the treasury stock method), and the conversion of convertible preferred stock and the preferred warrant (using the if-converted method). See Note 12 below. Segment Information Operating segments are defined as components of an enterprise about which separate discrete information is available for evaluation by the chief operating decision maker, or decision-making group, in deciding how to allocate resources and in assessing performance. The Company views its operations and manages its business in one segment. Recently Adopted Accounting Pronouncements ASC 842 requires lessees to recognize the liabilities related to all leases, including operating leases, with a term greater than 12 months on the balance sheet and also requires lessees and lessors to disclose key information about their leasing transactions. The Company adopted this guidance on January 1, 2022, using the modified retrospective method and the Company elected the package of practical expedients upon transition, which retained the lease classification for leases that existed prior to the adoption of this guidance. The Company recorded both a right-of-use asset and a lease liability of approximately $0.2 million on its balance sheet upon the adoption of ASC 842. In December 2019, the FASB issued ASU No. 2019-12, Income Taxes (Topic 740): Simplifying the Accounting for Income Taxes (“ASU 2019-12”), which is intended to simplify various aspects related to accounting for income taxes. ASU 2019-12 removes certain exceptions to the general principles in ASC 740 and also clarifies and amends existing guidance to improve consistent application. The Company adopted this guidance on January 1, 2022 with no material impact to the Company’s financial statements upon adoption. Recently Issued Accounting Pronouncements In June 2016, the FASB issued ASU 2016-13, Financial Instruments-Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments, which was codified with its subsequent amendments as ASC 326. ASC 326 seeks to provide financial statement users with more decision-useful information about the expected credit losses on financial instruments, including trade receivables, and other commitments to extend credit held by a reporting entity at each reporting date. The amendments require an entity to replace the incurred loss impairment methodology in current U.S. GAAP with a methodology that reflects current expected credit losses and requires consideration of a broader range of reasonable and supportable information to inform credit loss estimates. The updated guidance is effective for the Company on January 1, 2023. The Company’s marketable securities portfolio consists entirely of available-for-sale debt securities and, as such, the adoption of this guidance did not have a material impact on its financial statements and disclosures upon adoption.

Marketable Securities

12 Months Ended

Dec. 31, 2022

Marketable Securities [Abstract]

Marketable Securities

MARKETABLE SECURITIES

The Company’s marketable securities consisted of the following (in thousands):


	December 31, 2022
	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses		Fair Value
Available-for-sale securities, short-term
Corporate debt securities	$	30,174	$	—	$	(249)	$	29,925
Asset-backed securities	3,006		—		(102)		2,904
U.S. treasury securities	15,032		—		(357)		14,675
Total available-for-sale securities, short-term	48,212		—		(708)		47,504
Available-for-sale securities, long-term
Corporate debt securities	15,880		—		(43)		15,837
Total available-for-sale securities, long-term	15,880		—		(43)		15,837
Total available-for-sale securities	$	64,092	$	—	$	(751)	$	63,341


	December 31, 2021
	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses		Fair Value
Available-for-sale securities, short-term
Commercial paper	$	47,939	$	—	$	—	$	47,939
Corporate debt securities	7,992		—		(11)		7,981
Asset-backed securities	16,177		—		(22)		16,155
Total available-for-sale securities, short-term	72,108		—		(33)		72,075
Available-for-sale securities, long-term
Corporate debt securities	16,816		—		(103)		16,713
Asset-backed securities	3,013		—		(25)		2,988
U.S. treasury securities	11,988		—		(70)		11,918
Total available-for-sale securities, long-term	31,817		—		(198)		31,619
Total available-for-sale securities	$	103,925	$	—	$	(231)	$	103,694

As of December 31, 2022, the Company’s available-for-sale securities classified as short-term mature in one year or less and the Company’s available-for-sale securities classified as long-term mature within two years. Certain of the Company’s available-for-sale marketable securities that were in an unrealized loss position as of December 31, 2022 have been in a loss position for between 12 to 15 months; however, unrealized losses on available-for-sale securities as of December 31, 2022 were not significant and were primarily due to changes in interest rates, including market credit spreads, and not due to increased credit risks associated with specific securities. Accordingly, no other-than-temporary impairment was recorded for the years ended December 31, 2022 and 2021. There were no realized gains or losses for the years ended December 31, 2022 and 2021. The Company does not intend to sell these securities and it is not more likely than not that the Company will be required to sell the investments before recovery of their amortized cost bases, which may be at maturity.

Fair Value Measurements

12 Months Ended

Dec. 31, 2022

Fair Value Disclosures [Abstract]

Fair Value Measurements

FAIR VALUE MEASUREMENTS

The Company’s financial assets and liabilities subject to fair value measurement on a recurring basis and the level of inputs used for such measurements were as follows (in thousands):


	Fair value measurements at reporting date using
	Quoted Prices in Active Markets for Identical Assets (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)		Fair Value at December 31, 2022
Assets included in:
Cash and cash equivalents
Money market securities	$	129,100	$	—	$	—	$	129,100
Marketable securities
Corporate debt securities	—		45,762		—		45,762
Asset-backed securities	—		2,904		—		2,904
U.S. treasury securities	—		14,675		—		14,675
Total fair value	$	129,100	$	63,341	$	—	$	192,441


	Fair value measurements at reporting date using
	Quoted Prices in Active Markets for Identical Assets (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)		Fair Value at December 31, 2021
Assets included in:
Cash and cash equivalents
Money market securities	$	121,162	$	—	$	—	$	121,162
Marketable securities
Commercial paper	—		47,939		—		47,939
Corporate debt securities	—		24,694		—		24,694
Asset-backed securities	—		19,143		—		19,143
U.S. treasury securities	—		11,918		—		11,918
Total fair value	$	121,162	$	103,694	$	—	$	224,856

The fair value of the Company’s money market funds is determined using quoted market prices in active markets for identical assets.

The fair value for the available-for-sale marketable securities is determined based on valuation models using inputs that are observable either directly or indirectly (Level 2 inputs), such as quoted prices for similar assets or liabilities, yield curve, volatility factors, credit spreads, default rates, loss severity, current market and contractual prices for the underlying instruments or debt, broker and dealer quotes, as well as other relevant economic measures.

Series B Convertible Preferred Stock Tranche Rights Liability

The fair value for the tranche liability was estimated as a forward contract using a valuation model, calibrated at issuance. The valuation model at issuance estimated the implied value of the Series B stock as of the expected milestone date utilizing the probability of milestone achievement, expected timing of milestone achievement, and risk-free rate. The model was calibrated such that the value of the initial tranche and the forward contract were equal to the initial tranche proceeds at issuance. Subsequently, the fair value of the liability was discounted to the valuation date and adjusted for probability of the achievement of the milestone event. The calibrated valuation model was updated as of the end of each reporting period and in the Stay Private scenario utilized in the hybrid methodology as of June 17, 2021 (the date of the Milestone Closing, as further discussed in Note 7). Significant estimates and assumptions impacting fair value include the discount rate,

expected time to the Milestone Closing, and probability of the Milestone Closing. The discount rate was equal to the risk-free rate commensurate with the estimated timing of the Milestone Closing.

The following assumptions were used in the estimation of the fair value of the tranche liability as a forward contract as of each of the dates indicated:


	June 17, 2021	December 31, 2020
Risk-free interest rate	0.07%	0.12%
Expected time to Milestone Closing (in years)	0.8	1.3
Probability of achievement of Milestone Closing	100%	65%

For the other portion of the hybrid method used as of June 17, 2021, the fair value for the tranche liability was estimated based upon an allocation of the underlying equity value, which was determined using an IPO value as estimated through analysis of IPOs for comparable guideline companies, to arrive at a value per share in the IPO scenario. The estimated fair value of the tranche liability was $81.2 million and $5.0 million as of the Milestone Closing on June 17, 2021 and December 31, 2020, respectively. The significant increase in the June 17, 2021 valuation stemmed from both a shift in methodology from an option pricing method (“OPM”) to a Hybrid Model where the concluded value of the forward tranche was derived by the sum of the probability weighted present value of the forward tranche in the Stay Private and IPO scenarios (with the former including all other potential exit scenarios other than an imminent IPO), as well as the increase in the probability of achievement of the Milestone Closing. The resulting difference in estimated fair value was recognized as a change in fair value within other income in the accompanying statements of operations.

The tranche liability was revalued each reporting period with the change in fair value recorded in the accompanying statements of operations through the issuance of the Milestone Shares on June 17, 2021. Following the Milestone Closing, the remaining tranche liability was reclassified to convertible preferred stock on the balance sheet.

Series A-1 Convertible Preferred Stock Warrant Liability

On October 19, 2018, the Company issued a ten-year warrant (the “Series A-1 Warrant”) to purchase up to an aggregate of 447,426 shares of Series A-1 convertible preferred stock at an exercise price of $2.794 on or before October 18, 2028.

The warrant liability met the definition of a freestanding financial instrument, as it was legally detachable and separately exercisable from the initial closing of the Series A-1 convertible preferred stock. As such, it was revalued each reporting period with the change in fair value recorded in the accompanying statements of operations until the warrant was exercised on June 22, 2021.

The fair value of the warrant liability was estimated using the OPM backsolve method as of December 31, 2020 and using a hybrid method, which included an OPM backsolve in the Stay Private scenario as of June 22, 2021. The following assumptions were used in the estimation of the fair value of the warrant liability using the OPM backsolve method as of each of the dates indicated:


	June 22, 2021	December 31, 2020
Risk-free interest rate	0.25%	0.13%
Expected term (in years)	2.0	2.0
Expected volatility	90%	90%
Expected dividend yield	0%	0%

The hybrid method used to value the warrant liability at June 22, 2021 considered both the underlying equity value determined using the OPM backsolve method in a Stay Private scenario, as well as the underlying equity value that was determined using an expected IPO value as estimated through analysis of IPOs for comparable guideline companies, to arrive at a value per share in the IPO scenario. The underlying equity values from each approach were probability weighted

based upon the expected likelihood of each scenario. The fair value of the warrant liability was estimated to be $12.02 and $0.85 as of June 22, 2021 and December 31, 2020, respectively.

The following table provides a reconciliation of the tranche liability and warrant liability measured at fair value using Level 3 significant unobservable inputs (in thousands):


	Series A-1 Preferred Stock Warrant		Series B Tranche Rights		Total
Balance, January 1, 2021	$	380	$	5,033	$	5,413
Change in fair value	5,000		76,157		81,157
Settlement of tranche liability due to issuance of Milestone Shares	—		(81,190)		(81,190)
Settlement of warrant liability upon exercise of warrant	(5,380)		—		(5,380)
Balance, December 31, 2021	$	—	$	—	$	—

- Definition

The entire disclosure for the fair value of financial instruments (as defined), including financial assets and financial liabilities (collectively, as defined), and the measurements of those instruments as well as disclosures related to the fair value of non-financial assets and liabilities. Such disclosures about the financial instruments, assets, and liabilities would include: (1) the fair value of the required items together with their carrying amounts (as appropriate); (2) for items for which it is not practicable to estimate fair value, disclosure would include: (a) information pertinent to estimating fair value (including, carrying amount, effective interest rate, and maturity, and (b) the reasons why it is not practicable to estimate fair value; (3) significant concentrations of credit risk including: (a) information about the activity, region, or economic characteristics identifying a concentration, (b) the maximum amount of loss the entity is exposed to based on the gross fair value of the related item, (c) policy for requiring collateral or other security and information as to accessing such collateral or security, and (d) the nature and brief description of such collateral or security; (4) quantitative information about market risks and how such risks are managed; (5) for items measured on both a recurring and nonrecurring basis information regarding the inputs used to develop the fair value measurement; and (6) for items presented in the financial statement for which fair value measurement is elected: (a) information necessary to understand the reasons for the election, (b) discussion of the effect of fair value changes on earnings, (c) a description of [similar groups] items for which the election is made and the relation thereof to the balance sheet, the aggregate carrying value of items included in the balance sheet that are not eligible for the election; (7) all other required (as defined) and desired information.

+ References + Details

Supplemental Financial Information

12 Months Ended

Dec. 31, 2022

Supplemental Financial Information [Abstract]

Supplemental Financial Information

SUPPLEMENTAL FINANCIAL INFORMATION

Prepaid expenses and other current assets consisted of the following (in thousands):


	December 31,
	2022		2021
Prepaid insurance	$	1,106	$	1,514
Research and development service agreements	1,077		2,591
Prepaid raw materials	199		83
Dues and subscriptions	105		96
Other	237		140
Total prepaid expenses and other current assets	$	2,724	$	4,424

Accrued expenses and other current liabilities consisted of the following (in thousands):


	December 31,
	2022		2021
Research and development	$	1,211	$	2,476
Compensation and other employee liabilities	2,008		1,102
Legal	—		130
Other	131		204
Total accrued expenses and other current liabilities	$	3,350	$	3,912

Leases

12 Months Ended

Dec. 31, 2022

Leases [Abstract]

Leases

LEASES

The Company has been subleasing space in Carmel, Indiana since March 1, 2020. The Company executed a new sublease for this space that was effective on February 1, 2021 and expires on August 30, 2023. The sublease does not provide the Company with any renewal options. The Company allows others to sublease a portion of the space from the Company for less than a one-year period. The Company recognizes sublease income in other income (expense) on its statements of operations and comprehensive loss. The Company expects to recognize approximately $9,000 in sublease income during 2023.

On September 28, 2022, the Company entered into a lease for office space in Charlottesville, Virginia with a lease term of 15 months beginning October 1, 2022. On December 1, 2022, the Company entered into a lease for additional office space in the same building in Charlottesville, Virginia with a lease term of 12 months beginning on January 1, 2023. There is no

automatic renewal for either of the Charlottesville, Virginia leases, but any holdover tenancy shall be on a month-to-month basis thereafter.

The following table summarizes quantitative information about the Company’s operating leases for the year ended December 31, 2022 (in thousands):



Operating leases
Operating lease cost	$	154
Less: sublease income	(43)
Operating lease expense	111
Short-term lease rent expense	13
Total rent expense	$	124

Supplemental information related to leases for the year ended December 31, 2022 was as follows (dollar amounts in thousands):


Operating cash flows from operating leases			$154
Right-of-use assets obtained in exchange for operating lease liabilities			$242
Weighted-average remaining lease term – operating leases (in years)			0.7
Weighted-average discount rate – operating leases			10.0%

As of December 31, 2022, the present value of maturities of the Company’s operating lease liabilities were as follows (in thousands):


Year ended December 31, 2023	$	109
Less: present value discount	(4)
Operating lease liabilities	$	105

Prior to the adoption of ASC 842, and for the year ended December 31, 2021, the Company recognized rent expense on a straight-line basis over the lease period and recorded deferred rent expense for rent expense incurred but not yet paid. During the year ended December 31, 2021, the Company recognized total rent expense of approximately $147,000, and recognized sublease income of approximately $66,000.

Convertible Preferred Stock	12 Months Ended
Convertible Preferred Stock	Dec. 31, 2022
Convertible Preferred Stock Tranche Liability and Warrant Liability [Abstract]
Convertible Preferred Stock	CONVERTIBLE PREFERRED STOCK Convertible Preferred Stock On June 9, 2021, the Board and the holders of more than 67% of the then-outstanding shares of Series B convertible preferred stock held by the Series B purchasers (the “Requisite Investors”) elected to waive the achievement of the milestone subject to the terms and conditions of the Series B Preferred Stock Purchase Agreement (the “Series B Agreement”) and consummate the subsequent closing (the “Milestone Closing”). On June 17, 2021, the Milestone Closing for the Series B convertible preferred stock occurred, resulting in the sale of 7,908,027 shares of Series B convertible preferred stock at $3.80 per share for gross proceeds of $30.0 million, bringing the total number of Series B convertible preferred shares outstanding to 19,770,070. See “Series B Convertible Preferred Stock Tranche Rights Liability” above in Note 4. On June 22, 2021, a warrant to purchase 447,426 shares of Series A-1 convertible preferred stock at an exercise price of $2.794 per share was exercised (see “Series A-1 Convertible Preferred Stock Warrant Liability” above in Note 4), bringing the total number of Series A-1 convertible preferred shares outstanding to 7,985,305. Conversion rights Shares of all series of convertible preferred stock were convertible into such number of fully paid and non-assessable shares of common stock as determined by dividing the original issuance price for such series by the applicable conversion price for such series then in effect. The initial conversion price per share for each series of convertible preferred stock was the original issue price applicable to such series as shown in the table above, subject to adjustment in the event of certain dilutive issuances. The convertible preferred stock original issuance price and conversion price were each subject to adjustment in the event of any stock dividend, stock split, combination or other similar recapitalization with respect to the convertible preferred stock. Each share of convertible preferred stock was convertible at any time at the option of the holder at the conversion ratio then in effect. In addition, each share of convertible preferred stock was to be automatically converted into common stock at the conversion ratio then in effect upon either (a) the closing of an underwritten public offering resulting in gross proceeds to the Company of at least $75 million and at a price per share equal to at least two times the Series B original issuance price, or $7.60 (subject to adjustment in the event of any stock dividend, stock split, combination or other similar recapitalization with respect to the Series B convertible preferred stock), or (b) the date and time, or the occurrence of an event, specified in such vote or written consent of at least 67% of the holders of the then-outstanding shares of Series B convertible preferred stock. On July 6, 2021, in connection with the closing of the IPO, 477,297 shares of Series A, 7,985,305 shares of Series A-1, and 19,770,070 shares of Series B convertible preferred stock, respectively, automatically converted into an equal number of shares of common stock. There were no shares of convertible preferred stock outstanding as of December 31, 2022 or 2021.

Stockholders' Equity	12 Months Ended
Stockholders' Equity	Dec. 31, 2022
Stockholders' Equity Note [Abstract]
Stockholders' Equity	STOCKHOLDERS’ EQUITY Authorized Shares On July 6, 2021, the Company issued 9,999,999 shares of common stock in the IPO, and on July 8, 2021, the Company issued an additional 1,499,999 shares of common stock that were purchased by the underwriters pursuant to the underwriters’ option to purchase additional shares at the public offering price less underwriting discounts and commissions. The price to the public for each share was $16.00. The aggregate net proceeds from the Company’s IPO, after underwriting discounts and commissions and other offering expenses of $15.4 million, were $168.6 million. Effective upon the closing of the IPO on July 6, 2021, the Company amended its certificate of incorporation such that the total number of shares of all classes of capital stock authorized to be issued was increased to 310,000,000, with 10,000,000 shares designated as preferred stock with a par value of $0.0001, and 300,000,000 shares designated as common stock with a par value of $0.0001. Common Stock As of December 31, 2022, the Company’s Amended and Restated Certificate of Incorporation authorized the issuance of 300,000,000 shares of common stock, $0.0001 par value per share. Each share of common stock is entitled to one voting right. Shelf Registration and At-The-Market Equity Offering On July 1, 2022, the Company filed a shelf registration statement on Form S-3 (the “Registration Statement”). Pursuant to the Registration Statement, the Company may offer and sell securities having an aggregate public offering price of up to $200.0 million. In connection with the filing of the Registration Statement, the Company also entered into a sales agreement with BofA Securities, Inc. and Stifel, Nicolaus & Company, Incorporated (the “Sales Agents”), as sales agents, pursuant to which the Company may issue and sell shares of its common stock for an aggregate offering price of up to $50.0 million under an at-the-market offering program (the “ATM”), which is included in the $200.0 million of securities that may be offered pursuant to the Registration Statement. Pursuant to the ATM, the Company will pay the Sales Agents a commission rate of up to 3.0% of the gross proceeds from the sale of any shares of common stock. The Company is not obligated to make any sales of shares of its common stock under the ATM. In October 2022, the Company issued 422,160 shares of common stock under the ATM for net proceeds of $3.8 million, at a weighted average price of $10.06 per share. Common Stock Warrants In accordance with ASC 815, the common stock warrants issued in 2014 through 2017 did not meet the definition of a derivative and were classified in stockholders’ equity (deficit) in the consolidated balance sheets. In June 2021, several holders of warrants to purchase the Company’s common stock exercised their warrants and purchased a total of 137,446 shares of common stock at an exercise price of $4.47. On July 6, 2021, the Company issued 178,847 shares of common stock in exchange for the remaining 248,247 outstanding common stock warrants at an exercise price of $4.47. As of December 31, 2022 and 2021, there were no common stock warrants outstanding.

- Definition

The entire disclosure for shareholders' equity comprised of portions attributable to the parent entity and noncontrolling interest, including other comprehensive income. Includes, but is not limited to, balances of common stock, preferred stock, additional paid-in capital, other capital and retained earnings, accumulated balance for each classification of other comprehensive income and amount of comprehensive income.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
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Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
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-Section 50
-Paragraph 13
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Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
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Reference 4: http://www.xbrl.org/2003/role/disclosureRef
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Reference 5: http://www.xbrl.org/2003/role/disclosureRef
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-URI https://asc.fasb.org/extlink&oid=126973232&loc=SL123496171-112644

Reference 6: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
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-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.3-04)
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Reference 7: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
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-URI https://asc.fasb.org/extlink&oid=126973232&loc=SL123496189-112644

Reference 8: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
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Reference 9: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 18
-Subparagraph (a)
-URI https://asc.fasb.org/extlink&oid=126973232&loc=SL123496189-112644

Reference 10: http://www.xbrl.org/2003/role/disclosureRef
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-Name Accounting Standards Codification
-Topic 505
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-URI https://asc.fasb.org/extlink&oid=126973232&loc=SL123496158-112644

Reference 11: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 14
-Subparagraph (a)
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Reference 12: http://www.xbrl.org/2003/role/disclosureRef
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Reference 13: http://www.xbrl.org/2003/role/disclosureRef
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Reference 14: http://www.xbrl.org/2003/role/disclosureRef
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-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 13
-Subparagraph (i)
-URI https://asc.fasb.org/extlink&oid=126973232&loc=SL123496158-112644

Reference 15: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
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-Section S99
-Paragraph 1
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Reference 16: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
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-Section 50
-Paragraph 6
-Subparagraph (a)
-URI https://asc.fasb.org/extlink&oid=126731327&loc=SL126733271-114008

+ Details

Stock-Based Compensation

12 Months Ended

Dec. 31, 2022

Share-Based Payment Arrangement [Abstract]

Stock-Based Compensation

STOCK-BASED COMPENSATION

2021 Equity Incentive Plan

The 2021 Equity Incentive Plan (the “2021 Plan”), which provides for the grant of incentive stock options to employees, and the grant of nonstatutory stock options, stock appreciation rights, restricted stock awards, restricted stock unit awards, performance awards and other forms of stock awards to employees, directors and consultants, became effective on June 30, 2021. The 2021 Plan is a successor to the Company’s Amended and Restated Stock Performance Plan that was adopted by the Board and stockholders on April 8, 2013 (as amended from time to time, most recently on November 20, 2020, the “2013 Plan”). Following the effectiveness of the 2021 Plan, no further grants may be made under the 2013 Plan; however, any outstanding equity awards granted under the 2013 Plan continue to be governed by the 2013 Plan. As of December 31, 2022, there were 3,326,220 options outstanding under the 2013 Plan.

Initially, the maximum number of shares of the Company’s common stock that may be issued under the 2021 Plan was 7,698,282 shares, which is the sum of (1) 3,550,000 new shares, plus (2) 667,104 shares that remained available for issuance under the Company’s 2013 Plan at the time the 2021 Plan became effective, plus (3) any shares subject to outstanding stock options or other stock awards that were granted under the 2013 Plan that, on or after the 2021 Plan became effective, terminate or expire prior to exercise or settlement, are settled in cash, are forfeited or repurchased because of the failure to vest, or are reacquired or withheld to satisfy a tax withholding obligation or the purchase or exercise price in accordance with the terms of the 2013 Plan. In addition, the number of shares of the Company’s common stock reserved for issuance under the 2021 Plan will automatically increase on January 1 of each calendar year, starting on January 1, 2022 through January 1, 2031, in an amount equal to 5% of the total number of shares of the Company’s common stock outstanding on December 31 of the fiscal year before the date of each automatic increase, or a lesser number of shares determined by the Board prior to the applicable January 1. On January 1, 2022, the Board increased the number of shares of common stock reserved for issuance under the 2021 Plan by 2,023,663 shares.

The maximum number of shares of the Company’s common stock that may be issued upon the exercise of incentive stock options under the 2021 Plan is 12,000,000. As of December 31, 2022, 9,721,945 shares were authorized for issuance under the 2021 Plan and 3,976,237 shares remained available for issuance under the 2021 Plan.

Stock Options

The Black-Scholes option-pricing model was used to estimate the fair value of stock options granted during the years ended December 31, 2022 and 2021 with the following weighted average assumptions:


	Year Ended December 31,
	2022	2021
Risk-free interest rate	1.7% – 4.2%	0.4% – 1.3%
Expected term (in years)	5.8 – 6.1	5.3 – 6.1
Expected volatility	90%	90%
Expected dividend yield	0%	0%

The weighted average grant date fair value of options granted during the years ended December 31, 2022 and 2021 was $3.79 per share and $1.93 per share, respectively.

Prior to the Company’s IPO, the fair value of the Company’s common stock underlying the stock options was historically determined by the Board with assistance from management and, occasionally with input from an independent third-party valuation firm. For the year ended December 31, 2020, management engaged an independent third-party valuation firm to provide an estimate of the fair value of its common stock, which was utilized as an input to the Company’s Black-Scholes options pricing model for stock options awarded during the first quarter of 2021. The December 31, 2020 fair value of common stock was determined considering a number of objective and subjective factors, including valuations of comparable companies, sales of convertible preferred stock, operating and financial performance, the lack of liquidity of the Company’s common stock and the general and industry-specific economic outlook. The fair value of the Company’s common stock as of June 30, 2021 was estimated based upon the per share offering price of the Company’s common stock to the public in its IPO which closed on July 6, 2021. The June 30, 2021 fair value for the Company’s common stock was utilized as an input for options granted by the Company to its Board on June 30, 2021, which was immediately prior to the IPO. As of June 30, 2021 and December 31, 2020, management estimated the fair value of a share of common stock to be $16.00 and $0.83, respectively.

As of December 31, 2020, management, with the assistance of an independent third-party valuation firm, estimated the fair value of a share of common stock utilizing the following assumptions:


Risk-free interest rate			0.13%
Expected time to liquidity event (in years)			2.0
Expected volatility			90%
Expected dividend yield			0%

The stock options granted after December 31, 2017 vest monthly over a range of 12 to 36 months or vest monthly over a total of 48 months following a one-year cliff and all have a ten-year contractual term. Stock options granted prior to December 31, 2017 were either fully vested upon grant or generally vested monthly over a range of three to 24 months and have a ten-year term. The Company became publicly traded in July 2021 and lacks company-specific historical and implied volatility information. Therefore, it estimates its expected stock volatility based on the historical volatility of a publicly traded set of peer companies. Due to the lack of historical exercise history, the expected term of the Company’s stock options has been determined using the “simplified” method for awards. The risk-free interest rate is determined by reference to the U.S. Treasury yield curve in effect at the time of grant of the award for time periods approximately equal to the expected term of the award. Expected dividend yield is zero based on the fact that the Company has never paid cash dividends and does not expect to pay any cash dividends in the foreseeable future.

The following table reflects summarized stock option activity:


	Stock Options	Weighted Average Exercise Price		Weighted Average Remaining Contractual Life (in years)	Aggregate Intrinsic Value (in thousands)
Outstanding at January 1, 2022	3,835,618	$	2.51
Granted	1,999,050	$	5.04
Exercised	(131,626)	$	0.93
Forfeited	(79,872)	$	6.35
Expired	(12,277)	$	16.00
Outstanding at December 31, 2022	5,610,893	$	3.36	8.1	$	14,980
Vested and exercisable at December 31, 2022	2,188,874	$	2.03	7.1	$	8,714

The intrinsic value of stock options exercised during the years ended December 31, 2022 and 2021was approximately $0.6 million and $0.1 million. As of December 31, 2022, total unrecognized compensation costs related to unvested stock option

awards granted was approximately $8.9 million, which the Company expects to recognize over a weighted-average period of approximately 2.6 years.

The Company recorded stock-based compensation expense related to stock options in the following expense categories of its statements of operations and comprehensive loss for the periods shown (in thousands):


	Year Ended December 31,
	2022		2021
General and administrative	$	2,163	$	690
Research and development	898		232
Total stock-based compensation	$	3,061	$	922

Employee Stock Purchase Plan

The 2021 Employee Stock Purchase Plan (the “ESPP”), which permits employees to purchase shares of the Company’s common stock, became effective on June 30, 2021. A total of 375,000 shares of the Company’s common stock were initially reserved for sale under the ESPP. The number of shares of the Company’s common stock reserved for issuance will automatically increase on January 1 of each calendar year, beginning on January 1, 2022 through January 1, 2031, by the lesser of (1) 1% of the total number of shares of the Company’s common stock outstanding on the last day of the fiscal year before the date of the automatic increase, and (2) 800,000 shares; provided that before the date of any such increase, the Board may determine that such increase will be less than the amount set forth in clauses (1) and (2). As of December 31, 2022, there are 779,732 shares authorized for issuance under the ESPP and have been no purchases of shares under the ESPP.

Income Taxes

12 Months Ended

Dec. 31, 2022

Income Tax Disclosure [Abstract]

Income Taxes

NOTE 10. INCOME TAXES

The Company has not recorded any tax provision or benefit for federal income taxes for the years ended December 31, 2022 and 2021. Current income taxes are based upon the year’s income taxable for federal and state tax reporting purposes. Deferred income taxes (benefits) are provided for certain income and expenses, which are recognized in different periods for tax and financial reporting purposes. Deferred tax assets and liabilities are computed for differences between the financial statements and tax bases of assets and liabilities that will result in taxable or deductible amounts in the future based on enacted tax laws and rates applicable to the period in which the differences are expected to affect taxable income, and NOL and R&D tax credit carryforwards.

A reconciliation of the expected tax computed at the U.S. statutory federal income tax rate to the total benefit for income taxes for the years ended December 31, 2022 and 2021 is as follows:


	Year Ended December 31,
	2022		2021
Statutory federal income tax rate	21.0	%	21.0	%
State tax, net of federal benefit	2.7		0.7
Non-deductible stock compensation	(0.5)		—
Rate change	(1.1)		(0.2)
Change in fair value of tranche and warrant liabilities	—		(16.9)
Non-deductible expense	—		(0.1)
R&D credit	—		(0.3)
Other	—		0.1
Change in valuation allowance	(22.1)		(4.3)
Income tax provision (benefit)	0.0	%	0.0	%

Significant components of the Company’s deferred tax assets as of December 31, 2022 and 2021 were as follows (in thousands):


	December 31,
	2022		2021
Deferred tax assets:
Net operating loss	$	13,125	$	10,819
R&D credit	1,381		1,381
Capitalized R&D	6,788		—
Stock compensation	675		263
Accruals and other temporary differences	179		58
Gross deferred tax assets	22,148		12,521
Valuation allowance	(22,118)		(12,520)
Total deferred tax assets	30		1
Deferred tax liabilities:
Depreciation	(30)		(1)
Total deferred tax liabilities	(30)		(1)
Net deferred tax assets	$	—	$	—

In assessing the realizability of deferred tax assets as of December 31, 2022 and 2021, management considered whether it is more likely than not that some portion or all of the deferred tax assets will be realized. The ultimate realization of deferred tax assets is dependent upon the generation of future taxable income during the periods in which those temporary differences become deductible or the NOL carryforwards and R&D tax credit carryforwards will be used. The Company has determined that it is not more likely than not that its deferred tax assets will be realized. Accordingly, a valuation allowance for the full amount of the net deferred tax assets has been recorded as of December 31, 2022 and 2021. The change in the valuation allowance as of December 31, 2022 from December 31, 2021 is due to the pretax loss incurred for the year ended December 31, 2022.

As of December 31, 2022, the Company had approximately $52.7 million of NOL carryforwards available for federal tax purposes which a portion begins to expire on December 31, 2028. As a result of the Tax Act of 2017, for U.S. income tax purposes, NOLs generated prior to December 31, 2017 can still be carried forward for up to 20 years, but NOLs generated after December 31, 2017 carryforward indefinitely, but are limited to 80% utilization against taxable income. Of the total federal NOL of $52.7 million, $6.4 million will begin to expire in 2028 and $46.2 million will not expire.

As of December 31, 2022, the Company also had approximately $61.3 million of state NOL carryforwards. The state NOLs begin to expire on December 31, 2028.

As of December 31, 2022, the Company had approximately $1.4 million of R&D credit carryforwards available for federal tax purposes, which begin to expire on December 31, 2023.

Utilization of the NOL and 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 Sections 382 and 383 of the Internal Revenue Code of 1986, as amended (the “Code”), as well as similar state provisions. These ownership changes may limit the amount of NOL and R&D credit carryforwards that can be used 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% of the outstanding stock of a company by certain stockholders. The Company has not completed a formal analysis of the potential impact of Section 382 on its deferred tax assets as of December 31, 2022. Until this analysis has been completed, the Company has not adjusted any of its deferred tax assets, including NOLs or R&D credits. The Company will reassess the amount of NOLs and credits subject to limitation under Section 382 when a study is complete. Due to the existence of the valuation allowance, future changes in the deferred tax assets related to these tax attributes will not impact the Company’s effective tax rate.

The Company is subject to U.S. federal and various state taxes. Generally, the tax years remain open for examination by the federal statute under a three-year statute of limitation; however, states generally keep their statutes open for four years. However, the Company’s tax years from 2003 and after are subject to examination by the United States and state taxing authorities due to the carry forward of unused NOLs and R&D credits.

- Definition

The entire disclosure for income taxes. Disclosures may include net deferred tax liability or asset recognized in an enterprise's statement of financial position, net change during the year in the total valuation allowance, approximate tax effect of each type of temporary difference and carryforward that gives rise to a significant portion of deferred tax liabilities and deferred tax assets, utilization of a tax carryback, and tax uncertainties information.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-SubTopic 10
-Section 50
-Paragraph 21
-URI https://asc.fasb.org/extlink&oid=121826272&loc=d3e32857-109319

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-SubTopic 10
-Section S99
-Paragraph 2
-Subparagraph (SAB Topic 11.C)
-URI https://asc.fasb.org/extlink&oid=122134291&loc=d3e330215-122817

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
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-Paragraph 17
-Subparagraph (b)
-URI https://asc.fasb.org/extlink&oid=121826272&loc=d3e32809-109319

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
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-Name Accounting Standards Codification
-Topic 740
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SAB TOPIC 6.I.5.Q1)
-URI https://asc.fasb.org/extlink&oid=122134291&loc=d3e330036-122817

Reference 5: http://www.xbrl.org/2003/role/disclosureRef
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-Name Accounting Standards Codification
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Reference 6: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
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Reference 7: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
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Reference 8: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-SubTopic 30
-Section 50
-Paragraph 2
-Subparagraph (a)
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Reference 9: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 235
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-08(h)(2))
-URI https://asc.fasb.org/extlink&oid=120395691&loc=d3e23780-122690

+ Details

Commitments and Contingencies	12 Months Ended
Commitments and Contingencies	Dec. 31, 2022
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	COMMITMENTS AND CONTINGENCIES The Company is not a party to any material legal proceedings and is not aware of any pending or threatened claims. From time to time, the Company may be subject to various legal proceedings and claims that arise in the ordinary course of its business activities. In November 2022, the Company entered into a License Agreement (“Agreement”) with Lonza Sales AG (“Lonza”) for a worldwide non-exclusive license to use certain Lonza technology in its research and development and drug manufacturing activities. Under the terms of the Agreement, in consideration of the licenses and consents granted to the Company, the Company is required to make an annual payment to Lonza (i) in Swiss Francs in the low six-digits where the Company manufactures ACU193 and (ii) in Swiss Francs in the mid six-digits per sublicense upon the anniversary date of the Agreement where a third party manufactures ACU193. In addition, if the Company generates Net Sales, as defined in the Agreement, of ACU193, the Company will be obligated to pay Lonza a royalty of low single digits based upon what entity manufactures ACU193 at that time.

Net Loss Per Share	12 Months Ended
Net Loss Per Share	Dec. 31, 2022
Earnings Per Share [Abstract]
Net Loss Per Share	NET LOSS PER SHARE The Company computes net loss per common share using the two-class method required for participating securities. Basic and diluted loss per share was the same for each period presented as the inclusion of all potential common stock outstanding would have been anti-dilutive. Potentially dilutive securities not included in the calculation of diluted net loss per common share, because to do so would be anti-dilutive, include shares issuable upon the exercise of stock options of 5,610,893 and 3,835,618 for the years ended December 31, 2022 and 2021, respectively.

Subsequent Event	12 Months Ended
Subsequent Event	Dec. 31, 2022
Subsequent Events [Abstract]
Subsequent Event	SUBSEQUENT EVENT Failure of Silicon Valley Bank On March 10, 2023, the Company became aware that the Federal Deposit Insurance Corporation (“FDIC”) issued a press release (the “FDIC press release”) stating that Silicon Valley Bank, Santa Clara, California (“SVB”) was closed by the California Department of Financial Protection and Innovation, which appointed the FDIC as receiver. On March 12, 2023, the Treasury Department announced that depositors of SVB would have access to all of their money starting March 13, 2023. The Company had approximately $1.8 million cash deposited with SVB as of December 31, 2022. On March 14, 2023, the Company regained access to the full amount of its cash that was deposited with SVB.

Basis of Presentation, Summary of Significant Accounting Policies and Recent Accounting Pronouncements (Policies)	12 Months Ended
	Dec. 31, 2022
Accounting Policies [Abstract]
Basis of Presentation	Basis of PresentationThe accompanying financial statements of the Company have been prepared in accordance with accounting principles generally accepted in the United States of America (“U.S. GAAP”) and pursuant to the rules and regulations of the U.S. Securities and Exchange Commission (“SEC”). In the opinion of management, all adjustments (consisting of normal recurring adjustments) have been made that are necessary to present fairly the Company’s financial position, and the results of its operations and its cash flows.
Emerging Growth Company	Emerging Growth CompanyFrom 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 impact of recently issued standards that are not yet effective will not have a material impact on the Company’s financial statements upon adoption. Under the Jumpstart Our Business Startups Act of 2012, as amended, the Company meets the definition of an emerging growth company and has elected the extended transition period for complying with new or revised accounting standards, which delays the adoption of these accounting standards until they would apply to private companies.
Use of Estimates	Use of Estimates The preparation of financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements, as well as the reported amounts of expenses during the reporting periods. These estimates and assumptions are based on the Company’s historical experience, and on various other factors that management believes are reasonable under the circumstances, the results of which form the basis for making judgments about the carrying values of assets and liabilities and the recording of expenses that are not readily apparent from other sources. Actual results may differ from these estimates under different assumptions or conditions. To the extent there are material differences between the estimates and actual results, the Company’s future results of operations will be affected.
Reclassifications	Reclassifications Certain prior year amounts have been reclassified for consistency with the current period presentation. Accrued clinical trial expenses are presented as a separate line on the balance sheets and statements of cash flows, whereas these accrued expenses were previously included in accrued expenses and other current liabilities. These reclassifications had no effect on the reported results of operations.
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. The Company’s cash equivalents consist of funds held in several money market accounts.
Marketable Securities	Marketable Securities The Company’s marketable securities portfolio consists primarily of investments in money market funds, commercial paper, asset-backed securities, U.S. treasury securities and short-term highly liquid, high credit quality corporate debt securities. The Company considers its marketable securities to be available-for-sale. Available-for-sale securities are classified as cash equivalents, or as short-term or long-term marketable securities based on the maturity date at time of purchase and their availability to meet current operating requirements. Available-for-sale securities that mature in three months or less from the date of purchase are classified as cash equivalents. Available-for-sale securities, excluding cash equivalents, that mature in one year or less are classified as short-term marketable securities and those that mature in more than one year are classified as long-term. Securities that are classified as available-for-sale are measured at fair value; see “Fair Value of Financial Instruments” below. Any premium arising at purchase is amortized to the earliest call date and any discount arising at purchase is accreted to maturity. Amortization and accretion of premiums and discounts are recorded along with interest income on investments in interest income, net in the statements of operations and comprehensive loss. Unrealized gains and losses are excluded from earnings and are reported as a component of other comprehensive income. The Company periodically evaluates whether declines in fair values of its available-for-sale securities below their book value are other-than-temporary. This evaluation consists of several qualitative and quantitative factors regarding the severity and duration of the unrealized loss, as well as the Company’s ability and intent to hold the available-for-sale security until a forecasted recovery occurs. The Company does not generally intend to sell its available-for-sale securities; however, the Company assesses whether it is more likely than not that it will be required to sell any security before recovery of its amortized cost basis. Realized gains and losses and declines in fair value judged to be other-than-temporary on available-for-sale securities will be included in other expense, net. The cost of investments sold will be calculated using the specific-identification method.
Concentrations of Credit Risk	Concentrations of Credit Risk Financial instruments that potentially subject the Company to significant concentration of credit risk consist primarily of cash, cash equivalents and marketable securities. The Company maintains deposits in financial institutions in excess of government insured limits. Management believes that the Company is not exposed to significant credit risk as the Company’s cash and cash equivalents are held at financial institutions that management believes to be of high credit quality. The Company has not experienced any losses due to credit risk on such accounts during any of the periods presented.
Fair Value of Financial Instruments	Fair Value of Financial Instruments The Company’s financial assets and liabilities are accounted for in accordance with Accounting Standards Codification (“ASC”) 820, Fair Value Measurements and Disclosures, which defines fair value as the exchange price that would be received for an asset or paid to transfer a liability (an exit price) in the principal or most advantageous market for the asset or liability in an orderly transaction between market participants on the measurement date. The fair value hierarchy requires an entity to maximize the use of observable inputs when measuring fair value and classifies those inputs into three levels: Level 1 — Observable inputs, such as quoted prices in active markets for identical assets or liabilities. Level 2 — Inputs other than Level 1 inputs that are either directly or indirectly observable, such as quoted prices for similar assets or liabilities; quoted prices in markets that are not active; or other inputs that are observable or can be corroborated by observable market data for substantially the full term of the instrument’s anticipated life. Level 3 — Unobservable inputs in which there is little or no market data, which require the reporting entity to develop its own assumptions. To the extent the valuation is based on models or inputs that are less observable or unobservable in the market, the determination of fair values requires more judgement. Accordingly, the degree of judgement exercised by management in determining fair value is greatest for instruments categorized as Level 3. A financial instrument’s level within the fair value hierarchy is based on the lowest level of any input that is significant to the fair value measurement. The carrying values reported in the Company’s balance sheets for cash (excluding cash equivalents which are recorded at fair value on a recurring basis), accounts payable and accrued expenses are reasonable estimates of their fair values due to the short-term nature of these items.
Property and Equipment	Property and Equipment Property and equipment consists primarily of computer equipment and furniture and fixtures and is stated at cost and depreciated using the straight-line method over the estimated useful lives of the assets, which is generally three years for computer-related assets and five years for furniture.
Leases	Leases Effective as of January 1, 2022, the Company accounts for its leases under ASC 842, Leases. Under this guidance, arrangements meeting the definition of a lease are classified as operating or financing leases and are recorded on the balance sheet as both a right-of-use asset and a lease liability, calculated by discounting fixed lease payments over the lease term at the rate implicit in the lease or the Company’s incremental borrowing rate. Lease liabilities are increased by interest and reduced by payments each period, and right-of-use assets are amortized over the lease term. For operating leases, interest on the lease liability and the amortization of the right-of-use asset results in straight-line rent expense over the lease term. Variable lease expenses are recorded when incurred and not included in the measurement of right-of-use assets and lease liabilities. ASC 842 provides practical expedients for an entity’s ongoing accounting. In calculating right-of-use assets and lease liabilities, the Company has elected to combine lease and non-lease components. Additionally, the Company has elected to apply the practical expedient related to short-term leases (i.e., leases having initial terms of 12 months or less at commencement date) as an accounting policy election. For short-term leases, the Company will not recognize a right-of-use asset or lease liability, but instead will recognize lease payments as an expense on a straight-line basis over the lease term. Prior to the adoption of ASC 842 on January 1, 2022, the Company accounted for its leases under ASC 840, Leases.
Convertible Preferred Stock	Convertible Preferred Stock The Company recorded shares of convertible preferred stock at their respective fair values on the dates of issuance, net of issuance costs. The Company applied the guidance in ASC 480-10-S99-3A, SEC Staff Announcement: Classification and Measurement of Redeemable Securities, and therefore classified the Series A, Series A-1 and Series B convertible preferred stock as mezzanine equity. The convertible preferred stock was recorded outside of stockholders’ deficit because, in the event of certain deemed liquidation events considered not solely within the Company’s control, such as a merger, acquisition and sale of all or substantially all of the Company’s assets, the convertible preferred stock would have become redeemable at the option of the holders. In the event of a change of control of the Company, proceeds received from the sale of such shares would have been distributed in accordance with the corresponding liquidation preferences. The Company did not adjust the carrying values of the convertible preferred stock to the deemed liquidation values of such shares since a liquidation event was not probable at any of the reporting dates. As mentioned above in Note 1, in connection with the closing of the IPO, all of the outstanding shares of Series A, Series A-1 and Series B convertible preferred stock automatically converted into an equal number of shares of common stock on July 6, 2021.
Preferred Stock Tranche Rights Liability	Preferred Stock Tranche Rights Liability The Company determined that its obligation to issue, and the Company’s investors’ right to purchase, additional shares of Series B convertible preferred stock pursuant to a subsequent closing, (deemed the “Milestone Closing” in Note 7) represented a freestanding financial instrument (the “tranche liability”), as it was legally detachable and separately exercisable from the initial closing of the Series B convertible preferred stock. The tranche liability was initially recorded at fair value. The proceeds from the sale of the convertible preferred stock were first allocated to the fair value of the tranche liability with the remaining proceeds from the sale of the convertible preferred stock allocated to the Series B convertible preferred stock. The tranche liability was remeasured at each reporting period and upon the exercise of the obligation, with gains and losses arising from subsequent changes in its fair value recognized in other income and expense in the statements of operations and comprehensive loss. The Milestone Closing occurred on June 17, 2021, and as a result, the remaining value of the tranche liability was reclassified to convertible preferred stock on the balance sheet.
Preferred Stock Warrant Liability	Preferred Stock Warrant Liability The Company accounted for the warrant to purchase Series A-1 convertible preferred stock as a liability as this warrant was a freestanding financial instrument that required the Company to transfer assets upon exercise. The warrant liability was initially recorded at fair value. The warrant liability was remeasured at each reporting period and upon the exercise of the applicable warrant, with gains and losses arising from subsequent changes in its fair value recognized in other income and expense in the statements of operations and comprehensive loss. The warrant was exercised on June 22, 2021, and the remaining value of the warrant liability was reclassified to convertible preferred stock on the balance sheet.
Common Stock Warrants	Common Stock WarrantsThe Company assesses whether warrants issued require accounting as derivatives. The Company determined that its common stock warrants were (1) indexed to the Company’s own stock and (2) classified in stockholders’ equity in accordance with FASB ASC Topic 815, Derivatives and Hedging. As such, the Company concluded the warrants met the scope exception for determining whether the instruments require accounting as derivatives and should be classified in stockholders’ equity.
Research and Development Expenses	Research and Development Expenses Research and development expenses primarily consist of consultants and materials, biologic storage, salaries and other personnel-related expenses related to research and development activities and are expensed as incurred. Payments for these activities are based on the terms of the individual agreements, which may differ from the pattern of costs incurred, and are reflected on the balance sheets as prepaid or accrued expenses. The Company records accruals for estimated ongoing research costs. When evaluating the adequacy of the accrued liabilities, the Company analyzes progress of the studies, including the phase or completion of events, invoices received and contracted costs. Clinical trial costs are a significant component of research and development expenses and include costs associated with third-party contractors. The Company accrues and expenses costs for clinical trial activities performed by third parties based upon the work completed to date for each clinical trial in accordance with established agreements. The Company determines its costs through discussions with internal clinical stakeholders and outside service providers as to the progress or stage of completion of clinical trials or services and the contracted fee to be paid for such services. In the event advance payments are made to an outside service provider, the payments are recorded within prepaid expenses and other current assets on the Balance Sheet and subsequently recognized as research and development expense in the Statement of Operations when the associated services have been performed. As actual costs become known, the Company adjusts its estimates, liabilities and assets. Inputs used in the determination of estimates discussed above may vary from actual, which will result in adjustments to research and development expense in future periods.
Stock-based Compensation	Stock-based Compensation The Company expenses stock-based compensation to employees, non-employees and board members over the requisite service period based on the estimated grant date fair value of the awards and actual forfeitures. The Company estimates the fair value of stock option grants using the Black-Scholes option pricing model, which requires the use of a number of complex assumptions including the fair value of the common stock, expected volatility, risk-free interest rate, expected dividends, and the expected term of the option. The assumptions used in calculating the fair value of stock-based awards represent management’s best estimates and involve inherent uncertainties and the application of management’s judgment. Stock-based awards with graded-vesting schedules are recognized on a straight-line basis over the requisite service period for each separately vesting portion of the award. All stock-based compensation costs are recorded in research and development expense or general and administrative expense in the statements of operations and comprehensive loss based upon the respective employee’s or non-employee’s roles within the Company. Forfeitures are recorded as they occur.
Income Taxes	Income Taxes Income taxes are recorded in accordance with ASC 740, Income Taxes (“ASC 740”), which provides for deferred taxes using an asset and liability approach. The Company recognizes deferred tax assets and liabilities for the expected future tax consequences of events that have been included in the financial statements or tax returns. Deferred tax assets and liabilities are determined based on the difference between the financial statement and tax bases of assets and liabilities using enacted tax rates in effect for the year in which the differences are expected to reverse, and net operating loss (“NOL”) carryforwards and research and development (“R&D”) tax credit carryforwards. Valuation allowances are provided if, based upon the weight of available evidence, it is more likely than not that some or all of the deferred tax assets will not be realized. The Company has recorded a full valuation allowance to reduce its net deferred income tax assets to zero. In the event the Company were to determine that it would be able to realize some or all of its deferred income tax assets in the future, an adjustment to the deferred income tax asset valuation allowance would increase income in the period such determination was made. The Company accounts for uncertain tax positions in accordance with the provisions of ASC 740. When uncertain tax positions exist, the Company recognizes the tax benefit of tax positions to the extent that the benefit would more likely than not be realized assuming examination by the taxing authority. The determination as to whether the tax benefit will more likely than not be realized is based upon the technical merits of the tax position as well as consideration of the available facts and circumstances.
Net Loss Per Share of Common Stock	Net Loss Per Share of Common Stock Basic net loss per share of common stock is calculated using the two-class method under which earnings are allocated to both common shares and participating securities based on their participation rights. Net loss attributable to common stockholders was not allocated to the convertible preferred stock as the holders of the convertible preferred stock did not have a contractual obligation to share in any losses. Basic net loss per share is calculated by dividing the net loss attributable to common shares by the weighted-average number of shares of common stock outstanding during the period. Diluted net loss per share of common stock is computed by dividing the net loss using the weighted-average number of common shares and, if dilutive, potential common shares outstanding during the period. For the year ended December 31, 2022, potential common shares consisted of stock options. For the year ended December 31, 2021, potential common shares consisted of stock options and warrants to purchase common stock (using the treasury stock method), and the conversion of convertible preferred stock and the preferred warrant (using the if-converted method).
Segment Information	Segment Information Operating segments are defined as components of an enterprise about which separate discrete information is available for evaluation by the chief operating decision maker, or decision-making group, in deciding how to allocate resources and in assessing performance. The Company views its operations and manages its business in one segment.
Recently Adopted Accounting Pronouncements and Recently Issued Accounting Pronouncements	Recently Adopted Accounting Pronouncements ASC 842 requires lessees to recognize the liabilities related to all leases, including operating leases, with a term greater than 12 months on the balance sheet and also requires lessees and lessors to disclose key information about their leasing transactions. The Company adopted this guidance on January 1, 2022, using the modified retrospective method and the Company elected the package of practical expedients upon transition, which retained the lease classification for leases that existed prior to the adoption of this guidance. The Company recorded both a right-of-use asset and a lease liability of approximately $0.2 million on its balance sheet upon the adoption of ASC 842. In December 2019, the FASB issued ASU No. 2019-12, Income Taxes (Topic 740): Simplifying the Accounting for Income Taxes (“ASU 2019-12”), which is intended to simplify various aspects related to accounting for income taxes. ASU 2019-12 removes certain exceptions to the general principles in ASC 740 and also clarifies and amends existing guidance to improve consistent application. The Company adopted this guidance on January 1, 2022 with no material impact to the Company’s financial statements upon adoption. Recently Issued Accounting Pronouncements In June 2016, the FASB issued ASU 2016-13, Financial Instruments-Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments, which was codified with its subsequent amendments as ASC 326. ASC 326 seeks to provide financial statement users with more decision-useful information about the expected credit losses on financial instruments, including trade receivables, and other commitments to extend credit held by a reporting entity at each reporting date. The amendments require an entity to replace the incurred loss impairment methodology in current U.S. GAAP with a methodology that reflects current expected credit losses and requires consideration of a broader range of reasonable and supportable information to inform credit loss estimates. The updated guidance is effective for the Company on January 1, 2023. The Company’s marketable securities portfolio consists entirely of available-for-sale debt securities and, as such, the adoption of this guidance did not have a material impact on its financial statements and disclosures upon adoption.

Marketable Securities (Tables)

12 Months Ended

Dec. 31, 2022

Marketable Securities [Abstract]

Summary of Marketable Securities

The Company’s marketable securities consisted of the following (in thousands):


	December 31, 2022
	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses		Fair Value
Available-for-sale securities, short-term
Corporate debt securities	$	30,174	$	—	$	(249)	$	29,925
Asset-backed securities	3,006		—		(102)		2,904
U.S. treasury securities	15,032		—		(357)		14,675
Total available-for-sale securities, short-term	48,212		—		(708)		47,504
Available-for-sale securities, long-term
Corporate debt securities	15,880		—		(43)		15,837
Total available-for-sale securities, long-term	15,880		—		(43)		15,837
Total available-for-sale securities	$	64,092	$	—	$	(751)	$	63,341


	December 31, 2021
	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses		Fair Value
Available-for-sale securities, short-term
Commercial paper	$	47,939	$	—	$	—	$	47,939
Corporate debt securities	7,992		—		(11)		7,981
Asset-backed securities	16,177		—		(22)		16,155
Total available-for-sale securities, short-term	72,108		—		(33)		72,075
Available-for-sale securities, long-term
Corporate debt securities	16,816		—		(103)		16,713
Asset-backed securities	3,013		—		(25)		2,988
U.S. treasury securities	11,988		—		(70)		11,918
Total available-for-sale securities, long-term	31,817		—		(198)		31,619
Total available-for-sale securities	$	103,925	$	—	$	(231)	$	103,694

Fair Value Measurements (Tables)

12 Months Ended

Dec. 31, 2022

Fair Value Disclosures [Abstract]

Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis

The Company’s financial assets and liabilities subject to fair value measurement on a recurring basis and the level of inputs used for such measurements were as follows (in thousands):


	Fair value measurements at reporting date using
	Quoted Prices in Active Markets for Identical Assets (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)		Fair Value at December 31, 2022
Assets included in:
Cash and cash equivalents
Money market securities	$	129,100	$	—	$	—	$	129,100
Marketable securities
Corporate debt securities	—		45,762		—		45,762
Asset-backed securities	—		2,904		—		2,904
U.S. treasury securities	—		14,675		—		14,675
Total fair value	$	129,100	$	63,341	$	—	$	192,441


	Fair value measurements at reporting date using
	Quoted Prices in Active Markets for Identical Assets (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)		Fair Value at December 31, 2021
Assets included in:
Cash and cash equivalents
Money market securities	$	121,162	$	—	$	—	$	121,162
Marketable securities
Commercial paper	—		47,939		—		47,939
Corporate debt securities	—		24,694		—		24,694
Asset-backed securities	—		19,143		—		19,143
U.S. treasury securities	—		11,918		—		11,918
Total fair value	$	121,162	$	103,694	$	—	$	224,856

Fair Value Measurement Inputs and Valuation Techniques

The following assumptions were used in the estimation of the fair value of the tranche liability as a forward contract as of each of the dates indicated:


	June 17, 2021	December 31, 2020
Risk-free interest rate	0.07%	0.12%
Expected time to Milestone Closing (in years)	0.8	1.3
Probability of achievement of Milestone Closing	100%	65%

The following assumptions were used in the estimation of the fair value of the warrant liability using the OPM backsolve method as of each of the dates indicated:


	June 22, 2021	December 31, 2020
Risk-free interest rate	0.25%	0.13%
Expected term (in years)	2.0	2.0
Expected volatility	90%	90%
Expected dividend yield	0%	0%

As of December 31, 2020, management, with the assistance of an independent third-party valuation firm, estimated the fair value of a share of common stock utilizing the following assumptions:


Risk-free interest rate			0.13%
Expected time to liquidity event (in years)			2.0
Expected volatility			90%
Expected dividend yield			0%

Summary of the Tranche Liability and Warrant Liability Measured at Fair Value using Level 3 Significant Unobservable Inputs

The following table provides a reconciliation of the tranche liability and warrant liability measured at fair value using Level 3 significant unobservable inputs (in thousands):


	Series A-1 Preferred Stock Warrant		Series B Tranche Rights		Total
Balance, January 1, 2021	$	380	$	5,033	$	5,413
Change in fair value	5,000		76,157		81,157
Settlement of tranche liability due to issuance of Milestone Shares	—		(81,190)		(81,190)
Settlement of warrant liability upon exercise of warrant	(5,380)		—		(5,380)
Balance, December 31, 2021	$	—	$	—	$	—

Supplemental Financial Information (Tables)

12 Months Ended

Dec. 31, 2022

Supplemental Financial Information [Abstract]

Schedule of Prepaid Expenses and Other Current Assets

Prepaid expenses and other current assets consisted of the following (in thousands):


	December 31,
	2022		2021
Prepaid insurance	$	1,106	$	1,514
Research and development service agreements	1,077		2,591
Prepaid raw materials	199		83
Dues and subscriptions	105		96
Other	237		140
Total prepaid expenses and other current assets	$	2,724	$	4,424

Schedule of Accrued Expenses and Other Current Liabilities

Accrued expenses and other current liabilities consisted of the following (in thousands):


	December 31,
	2022		2021
Research and development	$	1,211	$	2,476
Compensation and other employee liabilities	2,008		1,102
Legal	—		130
Other	131		204
Total accrued expenses and other current liabilities	$	3,350	$	3,912

Leases (Tables)

12 Months Ended

Dec. 31, 2022

Leases [Abstract]

Summary of Lease, Cost

The following table summarizes quantitative information about the Company’s operating leases for the year ended December 31, 2022 (in thousands):



Operating leases
Operating lease cost	$	154
Less: sublease income	(43)
Operating lease expense	111
Short-term lease rent expense	13
Total rent expense	$	124

Supplemental information related to leases for the year ended December 31, 2022 was as follows (dollar amounts in thousands):


Operating cash flows from operating leases			$154
Right-of-use assets obtained in exchange for operating lease liabilities			$242
Weighted-average remaining lease term – operating leases (in years)			0.7
Weighted-average discount rate – operating leases			10.0%

Summary of Lessee, Operating Lease, Liability, Maturity

As of December 31, 2022, the present value of maturities of the Company’s operating lease liabilities were as follows (in thousands):


Year ended December 31, 2023	$	109
Less: present value discount	(4)
Operating lease liabilities	$	105

Stock-Based Compensation (Tables)

12 Months Ended

Dec. 31, 2022

Share-Based Payment Arrangement [Abstract]

Summary of Assumptions Used for Valuation of Fair Value of Stock Options

The Black-Scholes option-pricing model was used to estimate the fair value of stock options granted during the years ended December 31, 2022 and 2021 with the following weighted average assumptions:


	Year Ended December 31,
	2022	2021
Risk-free interest rate	1.7% – 4.2%	0.4% – 1.3%
Expected term (in years)	5.8 – 6.1	5.3 – 6.1
Expected volatility	90%	90%
Expected dividend yield	0%	0%

Fair Value Measurement Inputs and Valuation Techniques

The following assumptions were used in the estimation of the fair value of the tranche liability as a forward contract as of each of the dates indicated:


	June 17, 2021	December 31, 2020
Risk-free interest rate	0.07%	0.12%
Expected time to Milestone Closing (in years)	0.8	1.3
Probability of achievement of Milestone Closing	100%	65%

The following assumptions were used in the estimation of the fair value of the warrant liability using the OPM backsolve method as of each of the dates indicated:


	June 22, 2021	December 31, 2020
Risk-free interest rate	0.25%	0.13%
Expected term (in years)	2.0	2.0
Expected volatility	90%	90%
Expected dividend yield	0%	0%

As of December 31, 2020, management, with the assistance of an independent third-party valuation firm, estimated the fair value of a share of common stock utilizing the following assumptions:


Risk-free interest rate			0.13%
Expected time to liquidity event (in years)			2.0
Expected volatility			90%
Expected dividend yield			0%

Summary of Stock Option Activity

The following table reflects summarized stock option activity:


	Stock Options	Weighted Average Exercise Price		Weighted Average Remaining Contractual Life (in years)	Aggregate Intrinsic Value (in thousands)
Outstanding at January 1, 2022	3,835,618	$	2.51
Granted	1,999,050	$	5.04
Exercised	(131,626)	$	0.93
Forfeited	(79,872)	$	6.35
Expired	(12,277)	$	16.00
Outstanding at December 31, 2022	5,610,893	$	3.36	8.1	$	14,980
Vested and exercisable at December 31, 2022	2,188,874	$	2.03	7.1	$	8,714

Summary of Share-Based Compensation Expense Related to Stock Options


	Year Ended December 31,
	2022		2021
General and administrative	$	2,163	$	690
Research and development	898		232
Total stock-based compensation	$	3,061	$	922

Income Taxes (Table)

12 Months Ended

Dec. 31, 2022

Income Tax Disclosure [Abstract]

Schedule of Effective Income Tax Rate Reconciliation

A reconciliation of the expected tax computed at the U.S. statutory federal income tax rate to the total benefit for income taxes for the years ended December 31, 2022 and 2021 is as follows:


	Year Ended December 31,
	2022		2021
Statutory federal income tax rate	21.0	%	21.0	%
State tax, net of federal benefit	2.7		0.7
Non-deductible stock compensation	(0.5)		—
Rate change	(1.1)		(0.2)
Change in fair value of tranche and warrant liabilities	—		(16.9)
Non-deductible expense	—		(0.1)
R&D credit	—		(0.3)
Other	—		0.1
Change in valuation allowance	(22.1)		(4.3)
Income tax provision (benefit)	0.0	%	0.0	%

Schedule of Deferred Tax Assets and Liabilities

Significant components of the Company’s deferred tax assets as of December 31, 2022 and 2021 were as follows (in thousands):


	December 31,
	2022		2021
Deferred tax assets:
Net operating loss	$	13,125	$	10,819
R&D credit	1,381		1,381
Capitalized R&D	6,788		—
Stock compensation	675		263
Accruals and other temporary differences	179		58
Gross deferred tax assets	22,148		12,521
Valuation allowance	(22,118)		(12,520)
Total deferred tax assets	30		1
Deferred tax liabilities:
Depreciation	(30)		(1)
Total deferred tax liabilities	(30)		(1)
Net deferred tax assets	$	—	$	—

Description of Organization and Business Operations - Additional Information (Detail) $ / shares in Units, $ in Thousands				1 Months Ended	12 Months Ended
	Jul. 08, 2021 shares	Jul. 06, 2021 USD ($) $ / shares shares	Jun. 23, 2021	Oct. 31, 2022 USD ($) $ / shares shares	Dec. 31, 2022 USD ($)	Dec. 31, 2021 USD ($)
Subsidiary, Sale of Stock [Line Items]
Reverse stock split, conversion ratio			0.671
Common stock, shares, outstanding, increase (decrease) post transaction (in shares)		39,911,517
Accumulated deficit \| $					$ 170,427	$ 127,571
Working capital \| $					172,500	193,500
Common Stock
Subsidiary, Sale of Stock [Line Items]
Sale of stock, stock issuance costs \| $					$ 412	15,445
Common Stock Warrants \| Common Stock
Subsidiary, Sale of Stock [Line Items]
Number of securities called by warrants or rights (in shares)		178,847
Series A Convertible Preferred Stock
Subsidiary, Sale of Stock [Line Items]
Conversion of stock, shares converted (in shares)		477,297
Series A-1 Convertible Preferred Stock
Subsidiary, Sale of Stock [Line Items]
Conversion of stock, shares converted (in shares)		7,985,305
Series B Convertible Preferred Stock
Subsidiary, Sale of Stock [Line Items]
Sale of stock, stock issuance costs \| $						$ 16
Conversion of stock, shares converted (in shares)		19,770,070
Initial Public Offering
Subsidiary, Sale of Stock [Line Items]
Sale of stock, number of shares issued in transaction (in shares)		9,999,999
Sale of stock, price per share (in dollars per share) \| $ / shares		$ 16.00
Sale of stock, stock issuance costs \| $		$ 15,400
Sale of stock, consideration received on transaction \| $		$ 168,600
Over-Allotment Option
Subsidiary, Sale of Stock [Line Items]
Sale of stock, number of shares issued in transaction (in shares)	1,499,999
At The Market Offering
Subsidiary, Sale of Stock [Line Items]
Sale of stock, number of shares issued in transaction (in shares)				422,160
Sale of stock, price per share (in dollars per share) \| $ / shares				$ 10.06
Sale of stock, consideration received on transaction \| $				$ 3,800

Basis of Presentation, Summary of Significant Accounting Policies and Recent Accounting Pronouncements - Additional Information (Detail)		1 Months Ended	12 Months Ended
	Jul. 06, 2021 $ / shares shares	Jun. 30, 2021 $ / shares shares	Dec. 31, 2022 USD ($) segment shares	Dec. 31, 2021 USD ($) shares	Jan. 01, 2022 USD ($)	Jul. 07, 2021 shares
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cash equivalents			$ 129,100,000	$ 121,200,000
Deferred tax assets, net			0	0
Uncertain tax positions			0	0
Uncertain tax positions, interest or penalties recorded			$ 0	0
Number of operating segments \| segment			1
Right-of-use asset			$ 105,000	$ 0	$ 200,000
Operating lease liabilities			$ 105,000		$ 200,000
Series A-1 Preferred Stock Warrant
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Change in fair value [Extensible Enumeration]			Change in fair value of preferred stock tranche rights liability and preferred stock warrant liability	Change in fair value of preferred stock tranche rights liability and preferred stock warrant liability
Warrants outstanding (in shares) \| shares			0
Common Stock Warrants
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Warrants outstanding (in shares) \| shares			0	0		0
Exercise price (in dollars per share) \| $ / shares	$ 4.47	$ 4.47
Series B Tranche Rights
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Change in fair value [Extensible Enumeration]			Change in fair value of preferred stock tranche rights liability and preferred stock warrant liability	Change in fair value of preferred stock tranche rights liability and preferred stock warrant liability
Common Stock
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Exercise of common stock warrants (in shares) \| shares		137,446		137,446
Cashless exercise of common stock warrants (in shares) \| shares	178,847		4,746	178,847
Common Stock \| Common Stock Warrants
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Warrants outstanding (in shares) \| shares	248,247
Computer-related assets
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Estimated useful lives of the assets			3 years
Furniture
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Estimated useful lives of the assets			5 years

Marketable Securities - Summary of Marketable Securities (Details) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Marketable Securities [Line Items]
Amortized cost, short term	$ 48,212	$ 72,108
Gross unrealized gains, short term	0	0
Gross unrealized losses, short term	(708)	(33)
Fair value, short term	47,504	72,075
Amortized cost, long term	15,880	31,817
Gross unrealized gains, long term	0	0
Gross unrealized losses, long term	(43)	(198)
Fair value, long term	15,837	31,619
Amortized cost, total	64,092	103,925
Gross unrealized gains, total	0	0
Gross unrealized losses, total	(751)	(231)
Fair value, total	63,341	103,694
Commercial paper
Marketable Securities [Line Items]
Amortized cost, short term		47,939
Gross unrealized gains, short term		0
Gross unrealized losses, short term		0
Fair value, short term		47,939
Corporate debt securities
Marketable Securities [Line Items]
Amortized cost, short term	30,174	7,992
Gross unrealized gains, short term	0	0
Gross unrealized losses, short term	(249)	(11)
Fair value, short term	29,925	7,981
Amortized cost, long term	15,880	16,816
Gross unrealized gains, long term	0	0
Gross unrealized losses, long term	(43)	(103)
Fair value, long term	15,837	16,713
Asset-backed securities
Marketable Securities [Line Items]
Amortized cost, short term	3,006	16,177
Gross unrealized gains, short term	0	0
Gross unrealized losses, short term	(102)	(22)
Fair value, short term	2,904	16,155
Amortized cost, long term		3,013
Gross unrealized gains, long term		0
Gross unrealized losses, long term		(25)
Fair value, long term		2,988
U.S. treasury securities
Marketable Securities [Line Items]
Amortized cost, short term	15,032
Gross unrealized gains, short term	0
Gross unrealized losses, short term	(357)
Fair value, short term	$ 14,675
Amortized cost, long term		11,988
Gross unrealized gains, long term		0
Gross unrealized losses, long term		(70)
Fair value, long term		$ 11,918

Marketable Securities - Additional Information (Details)	12 Months Ended
	Dec. 31, 2022
Marketable Securities [Line Items]
Debt securities, available-for-sale, noncurrent, term	2 years
Minimum
Marketable Securities [Line Items]
Debt securities, available-for-sale, unrealized loss position period	12 months
Maximum
Marketable Securities [Line Items]
Debt securities, available-for-sale, current, term	1 year
Debt securities, available-for-sale, unrealized loss position period	15 months

Fair Value Measurements - Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis (Detail) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Marketable Securities [Abstract]
Total fair value	$ 192,441	$ 224,856
Quoted Prices in Active Markets for Identical Assets (Level 1)
Marketable Securities [Abstract]
Total fair value	129,100	121,162
Significant Other Observable Inputs (Level 2)
Marketable Securities [Abstract]
Total fair value	63,341	103,694
Significant Unobservable Inputs (Level 3)
Marketable Securities [Abstract]
Total fair value	0	0
Commercial paper
Marketable Securities [Abstract]
Marketable securities		47,939
Commercial paper \| Quoted Prices in Active Markets for Identical Assets (Level 1)
Marketable Securities [Abstract]
Marketable securities		0
Commercial paper \| Significant Other Observable Inputs (Level 2)
Marketable Securities [Abstract]
Marketable securities		47,939
Commercial paper \| Significant Unobservable Inputs (Level 3)
Marketable Securities [Abstract]
Marketable securities		0
Corporate debt securities
Marketable Securities [Abstract]
Marketable securities	45,762	24,694
Corporate debt securities \| Quoted Prices in Active Markets for Identical Assets (Level 1)
Marketable Securities [Abstract]
Marketable securities	0	0
Corporate debt securities \| Significant Other Observable Inputs (Level 2)
Marketable Securities [Abstract]
Marketable securities	45,762	24,694
Corporate debt securities \| Significant Unobservable Inputs (Level 3)
Marketable Securities [Abstract]
Marketable securities	0	0
Asset-backed securities
Marketable Securities [Abstract]
Marketable securities	2,904	19,143
Asset-backed securities \| Quoted Prices in Active Markets for Identical Assets (Level 1)
Marketable Securities [Abstract]
Marketable securities	0	0
Asset-backed securities \| Significant Other Observable Inputs (Level 2)
Marketable Securities [Abstract]
Marketable securities	2,904	19,143
Asset-backed securities \| Significant Unobservable Inputs (Level 3)
Marketable Securities [Abstract]
Marketable securities	0	0
U.S. treasury securities
Marketable Securities [Abstract]
Marketable securities	14,675	11,918
U.S. treasury securities \| Quoted Prices in Active Markets for Identical Assets (Level 1)
Marketable Securities [Abstract]
Marketable securities	0	0
U.S. treasury securities \| Significant Other Observable Inputs (Level 2)
Marketable Securities [Abstract]
Marketable securities	14,675	11,918
U.S. treasury securities \| Significant Unobservable Inputs (Level 3)
Marketable Securities [Abstract]
Marketable securities	0	0
Money market securities
Cash and Cash Equivalents [Abstract]
Cash and cash equivalents	129,100	121,162
Money market securities \| Quoted Prices in Active Markets for Identical Assets (Level 1)
Cash and Cash Equivalents [Abstract]
Cash and cash equivalents	129,100	121,162
Money market securities \| Significant Other Observable Inputs (Level 2)
Cash and Cash Equivalents [Abstract]
Cash and cash equivalents	0	0
Money market securities \| Significant Unobservable Inputs (Level 3)
Cash and Cash Equivalents [Abstract]
Cash and cash equivalents	$ 0	$ 0

Fair Value Measurements - Summary of Assumptions Used in Estimating the Fair Value of Preferred Stock Tranche Liability (Detail) - Series B Convertible Preferred Stock Tranche Rights Liability	Jun. 17, 2021 yr	Dec. 31, 2020 yr
Risk-free interest rate
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivative liability, measurement input	0.0007	0.0012
Expected time to Milestone Closing (in years)
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivative liability, measurement input	0.8	1.3
Probability of achievement of Milestone Closing
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivative liability, measurement input	1	0.65

Fair Value Measurements - Additional Information (Detail) - USD ($) $ / shares in Units, $ in Millions	Jun. 22, 2021	Jun. 17, 2021	Dec. 31, 2020	Oct. 19, 2018
Series A -1 Warrant
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Class of warrants or rights term				10 years
Number of securities called by warrants or rights (in shares)				447,426
Exercise price (in dollars per share)				$ 2.794
Fair value price (in dollars per share)	$ 12.02		$ 0.85
Series B Convertible Preferred Stock Tranche Rights Liability
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Financial liabilities at fair value		$ 81.2	$ 5.0

Fair Value Measurements - Summary of Fair Value of the Warrant Liability (Detail) - Series A-1 Convertible Preferred Stock Warrant Liability	Jun. 22, 2021 yr	Dec. 31, 2020 yr
Risk-free interest rate
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Warrants and rights outstanding, measurement input	0.0025	0.0013
Expected term (in years)
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Warrants and rights outstanding, measurement input	2.0	2.0
Expected volatility
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Warrants and rights outstanding, measurement input	0.90	0.90
Expected dividend yield
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Warrants and rights outstanding, measurement input	0	0

Fair Value Measurements - Summary of the Tranche Liability and Warrant Liability Measured at Fair Value using Level 3 Significant Unobservable Inputs (Detail) $ in Thousands	12 Months Ended
	Dec. 31, 2021 USD ($)
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning balance	$ 5,413
Change in fair value	81,157
Settlement of tranche liability due to issuance of Milestone Shares	(81,190)
Settlement of warrant liability upon exercise of warrant	(5,380)
Ending balance	0
Series B Tranche Rights
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning balance	5,033
Change in fair value	76,157
Settlement of tranche liability due to issuance of Milestone Shares	(81,190)
Ending balance	0
Series A-1 Preferred Stock Warrant
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning balance	380
Change in fair value	5,000
Settlement of warrant liability upon exercise of warrant	(5,380)
Ending balance	$ 0

Supplemental Financial Information - Schedule of Prepaid Expenses and Other Current Assets (Detail) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Supplemental Financial Information [Abstract]
Prepaid insurance	$ 1,106	$ 1,514
Research and development service agreements	1,077	2,591
Prepaid raw materials	199	83
Dues and subscriptions	105	96
Other	237	140
Total prepaid expenses and other current assets	$ 2,724	$ 4,424

Supplemental Financial Information - Schedule of Accrued Expenses and Other Current Liabilities (Detail) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Supplemental Financial Information [Abstract]
Research and development	$ 1,211	$ 2,476
Compensation and other employee liabilities	2,008	1,102
Legal	0	130
Other	131	204
Total accrued expenses and other current liabilities	$ 3,350	$ 3,912

Lease - Additional Information (Detail) - USD ($) $ in Thousands		12 Months Ended
	Feb. 01, 2021	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021	Dec. 01, 2022	Sep. 28, 2022
Lessee, Lease, Description [Line Items]
Sublease income			$ 43	$ 66
Total rent expense				$ 147
Carmel, Indiana \| Maximum
Lessee, Lease, Description [Line Items]
Sublease, term of contract	1 year
Charlottesville, Virginia
Lessee, Lease, Description [Line Items]
Operating lease term						15 months
Charlottesville, Virginia
Lessee, Lease, Description [Line Items]
Operating lease term					12 months
Forecast \| Carmel, Indiana
Lessee, Lease, Description [Line Items]
Sublease income		$ 9

Leases - Summary of Lease, Cost (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Operating leases
Operating lease cost	$ 154
Less: sublease income	(43)	$ (66)
Operating lease expense	111
Short-term lease rent expense	13
Total rent expense	$ 124

Leases - Schedule Of Supplemental Information Related To Lease (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Leases [Abstract]
Operating cash flows from operating leases	$ 154
Right-of-use assets obtained in exchange for operating lease liabilities	$ 242	$ 0
Weighted-average remaining lease term – operating leases (in years)	8 months 12 days
Weighted-average discount rate – operating leases	10.00%

Leases - Summary of Lessee, Operating Lease, Liability, Maturity (Detail) - USD ($) $ in Thousands	Dec. 31, 2022	Jan. 01, 2022
Leases [Abstract]
Year ended December 31, 2023	$ 109
Less: present value discount	(4)
Operating lease liabilities	$ 105	$ 200

Convertible Preferred Stock - Additional Information (Detail)			12 Months Ended
	Jul. 06, 2021 shares	Jun. 17, 2021 USD ($) $ / shares shares	Dec. 31, 2022 USD ($) $ / shares shares	Dec. 31, 2021 USD ($) shares	Jun. 22, 2021 $ / shares shares	Jun. 09, 2021	Dec. 31, 2020 shares	Oct. 19, 2018 $ / shares shares
Convertible Preferred Stock Tranche Liability And Warrant Liability [Line Items]
Proceeds from issuance of Series B milestone shares, net of issuance costs \| $			$ 0	$ 30,031,000
Number of times the redeemable convertible preferred stock equal to the share issue price			2
Sale of stock issue price per share (in dollars per share) \| $ / shares			$ 7.60
Percentage of votes in terms of shareholding needed for conversion into permanent equity			67.00%
Minimum
Convertible Preferred Stock Tranche Liability And Warrant Liability [Line Items]
Proceeds from initial public offer \| $			$ 75,000,000
Series A -1 Warrant
Convertible Preferred Stock Tranche Liability And Warrant Liability [Line Items]
Number of securities called by warrants or rights (in shares)								447,426
Exercise price (in dollars per share) \| $ / shares								$ 2.794
Series B Convertible Preferred Stock
Convertible Preferred Stock Tranche Liability And Warrant Liability [Line Items]
Percentage of stockholders elected to waive achievement of milestone						67.00%
Temporary equity shares issued during the period shares (in shares)				7,908,027
Shares outstanding (in shares)		19,770,070		0			11,862,043
Conversion of convertible preferred stock into common stock upon initial public offering (in shares)	19,770,070			(19,770,070)
Series B Convertible Preferred Stock \| Closing of Milestone
Convertible Preferred Stock Tranche Liability And Warrant Liability [Line Items]
Temporary equity shares issued during the period shares (in shares)		7,908,027
Temporary equity issue price per share (in dollars per share) \| $ / shares		$ 3.80
Proceeds from issuance of Series B milestone shares, net of issuance costs \| $		$ 30,000,000
Series A-1 Convertible Preferred Stock
Convertible Preferred Stock Tranche Liability And Warrant Liability [Line Items]
Shares outstanding (in shares)					7,985,305
Conversion of convertible preferred stock into common stock upon initial public offering (in shares)	7,985,305
Series A-1 Convertible Preferred Stock \| Series A -1 Warrant
Convertible Preferred Stock Tranche Liability And Warrant Liability [Line Items]
Number of securities called by warrants or rights (in shares)					447,426
Exercise price (in dollars per share) \| $ / shares					$ 2.794
Series A Convertible Preferred Stock
Convertible Preferred Stock Tranche Liability And Warrant Liability [Line Items]
Shares outstanding (in shares)				0			477,297
Conversion of convertible preferred stock into common stock upon initial public offering (in shares)	477,297			(477,297)
Convertible Preferred Stock
Convertible Preferred Stock Tranche Liability And Warrant Liability [Line Items]
Shares outstanding (in shares)			0	0

Stockholders' Equity - Additional Information (Detail) $ / shares in Units, $ in Thousands			1 Months Ended		12 Months Ended
	Jul. 08, 2021 shares	Jul. 06, 2021 USD ($) $ / shares shares	Oct. 31, 2022 USD ($) $ / shares shares	Jun. 30, 2021 $ / shares shares	Dec. 31, 2022 USD ($) votingRight $ / shares shares	Dec. 31, 2021 USD ($) $ / shares shares	Jul. 01, 2022 USD ($)	Jul. 07, 2021 shares
Class of Stock [Line Items]
Common stock and preferred stock, shares authorized (in shares)		310,000,000
Preferred stock, shares authorized (in shares)		10,000,000			10,000,000	10,000,000
Preferred stock, par value (in dollars per share) \| $ / shares		$ 0.0001			$ 0.0001	$ 0.0001
Common stock, shares authorized (in shares)		300,000,000			300,000,000	300,000,000
Common stock, par value (in dollars per share) \| $ / shares		$ 0.0001			$ 0.0001	$ 0.0001
Common stock, number of voting rights \| votingRight					1
Sale of stock, commission rate to sales agents							3.00%
Common Stock Warrants
Class of Stock [Line Items]
Class of warrants or right exercise price per share (in dollars per share) \| $ / shares		$ 4.47		$ 4.47
Total warrants (in shares)					0	0		0
Common Stock
Class of Stock [Line Items]
Sale of stock, stock issuance costs \| $					$ 412	$ 15,445
Exercise of common stock warrants (in shares)				137,446		137,446
Cashless exercise of common stock warrants (in shares)		178,847			4,746	178,847
Common Stock \| Common Stock Warrants
Class of Stock [Line Items]
Total warrants (in shares)		248,247
Initial Public Offering
Class of Stock [Line Items]
Sale of stock, number of shares issued in transaction (in shares)		9,999,999
Sale of stock, price per share (in dollars per share) \| $ / shares		$ 16.00
Sale of stock, stock issuance costs \| $		$ 15,400
Sale of stock, consideration received on transaction \| $		$ 168,600
Over-Allotment Option
Class of Stock [Line Items]
Sale of stock, number of shares issued in transaction (in shares)	1,499,999
Registration Statement
Class of Stock [Line Items]
Sale of stock, maximum authorized amount \| $							$ 200,000
At The Market Offering
Class of Stock [Line Items]
Sale of stock, number of shares issued in transaction (in shares)			422,160
Sale of stock, price per share (in dollars per share) \| $ / shares			$ 10.06
Sale of stock, consideration received on transaction \| $			$ 3,800
Sale of stock, maximum authorized amount \| $							$ 50,000

Stock-Based Compensation - Additional Information (Detail) - USD ($) $ / shares in Units, $ in Millions			12 Months Ended
	Dec. 31, 2022	Jun. 30, 2021	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020	Jan. 01, 2022
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock options outstanding (in shares)	5,610,893		5,610,893	3,835,618
Weighted average grant date fair value of options granted (in dollars per share)			$ 3.79	$ 1.93
Options, exercises in period, intrinsic value			$ 0.6	$ 0.1
Option, cost not yet recognized, amount	$ 8.9		$ 8.9
Stock Options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected dividend yield			0.00%	0.00%	0.00%
Weighted average period of recognition			2 years 7 months 6 days
Stock Options \| Granted after December 31, 2017
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period			48 months
Cliff period			1 year
Contractual term			10 years
Stock Options \| Granted prior to December 31, 2017
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Contractual term			10 years
Employee Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Percentage of outstanding stock maximum		1.00%
Common stock, capital shares reserved for future issuance (in shares)		375,000
Number of shares authorized (in shares)	779,732		779,732
Shares of common stock outstanding maximum (in shares)		800,000
Shares issued in period (in shares)	0
Common Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Fair value of a share (in dollars per share)		$ 16.00			$ 0.83
Minimum \| Stock Options \| Granted after December 31, 2017
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period			12 months
Minimum \| Stock Options \| Granted prior to December 31, 2017
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period			3 months
Maximum \| Stock Options \| Granted after December 31, 2017
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period			36 months
Maximum \| Stock Options \| Granted prior to December 31, 2017
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period			24 months
2013 Equity Incentive Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock options outstanding (in shares)	3,326,220		3,326,220
2013 Equity Incentive Plan \| Common Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares available for future grant (in shares)		667,104
2021 Equity Incentive Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock, capital shares reserved for future issuance (in shares)						2,023,663
Maximum threshold common stock issuable on exercise of incentive stock options (in shares)		12,000,000
2021 Equity Incentive Plan \| Common Stock, New Shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares available for future grant (in shares)		3,550,000
2021 Equity Incentive Plan \| Common Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares available for future grant (in shares)	3,976,237	7,698,282	3,976,237
Percentage of outstanding stock maximum		5.00%
Number of shares authorized (in shares)	9,721,945		9,721,945

Stock-Based Compensation - Summary of Assumptions Used for Valuation of Fair Value of Stock (Detail)	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Common Stock
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Risk-free interest rate			0.13%
Expected time to liquidity event (in years)			2 years
Expected volatility			90.00%
Expected dividend yield			0.00%
Stock Options
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Risk-free interest rate, minimum	1.70%	0.40%
Risk-free interest rate, maximum	4.20%	1.30%
Expected volatility	90.00%	90.00%
Expected dividend yield	0.00%	0.00%	0.00%
Minimum \| Stock Options
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Expected term (in years)	5 years 9 months 18 days	5 years 3 months 18 days
Maximum \| Stock Options
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Expected term (in years)	6 years 1 month 6 days	6 years 1 month 6 days

Stock-Based Compensation - Summary of Stock Option Activity (Detail) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2022 USD ($) $ / shares shares
Stock Options
Beginning balance (in shares) \| shares	3,835,618
Granted (in shares) \| shares	1,999,050
Exercised (in shares) \| shares	(131,626)
Forfeited (in shares) \| shares	(79,872)
Expired (in shares) \| shares	(12,277)
Ending balance (in shares) \| shares	5,610,893
Vested and exercisable (in shares) \| shares	2,188,874
Weighted Average Exercise Price
Beginning balance (in dollars per share) \| $ / shares	$ 2.51
Granted (in dollars per share) \| $ / shares	5.04
Exercised (in dollars per share) \| $ / shares	0.93
Forfeited (in dollars per share) \| $ / shares	6.35
Expired (in dollars per share) \| $ / shares	16.00
Ending balance (in dollars per share) \| $ / shares	3.36
Vested and exercisable (in dollars per share) \| $ / shares	$ 2.03
Weighted Average Remaining Contractual Life (in years)
Outstanding balance (in years)	8 years 1 month 6 days
Vested and exercisable (in years)	7 years 1 month 6 days
Ending balance, aggregate intrinsic value \| $	$ 14,980
Vested and exercisable, aggregate intrinsic value \| $	$ 8,714

Stock-Based Compensation - Summary of Share-Based Compensation Expense Related to Stock Options (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Total stock-based compensation	$ 3,061	$ 922
General and administrative
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Total stock-based compensation	2,163	690
Research and development
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Total stock-based compensation	$ 898	$ 232

Income Taxes - Additional Information (Details) - USD ($)	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Income Tax Contingency [Line Items]
Income tax expense (benefit)	$ 0	$ 0
Research Tax Credit Carryforward
Income Tax Contingency [Line Items]
Tax credit carryforwards	1,400,000
Domestic Tax Authority
Income Tax Contingency [Line Items]
Operating loss carryforwards	52,700,000
Operating loss carryforwards, subject to expiration	6,400,000
Operating loss carryforwards, not subject to expiration	46,200,000
State and Local Jurisdiction
Income Tax Contingency [Line Items]
Operating loss carryforwards	$ 61,300,000

- Definition

Amount of current income tax expense (benefit) and deferred income tax expense (benefit) pertaining to continuing operations.

+ References + Details

Income Taxes - Summary of U.S. Statutory Federal Income Tax Rate to the Total Benefit for Income Taxes (Details)	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Income Tax Disclosure [Abstract]
Statutory federal income tax rate	21.00%	21.00%
State tax, net of federal benefit	2.70%	0.70%
Non-deductible stock compensation	(0.50%)	0.00%
Rate change	(1.10%)	(0.20%)
Change in fair value of tranche and warrant liabilities	0.00%	(16.90%)
Non-deductible expense	0.00%	(0.10%)
R&D credit	0.00%	(0.30%)
Other	0.00%	0.10%
Change in valuation allowance	(22.10%)	(4.30%)
Income tax provision (benefit)	(0.00%)	(0.00%)

Income Taxes - Significant Components of the Company's Deferred Tax Assets (Details) - USD ($)	Dec. 31, 2022	Dec. 31, 2021
Income Tax Disclosure [Abstract]
Net operating loss	$ 13,125,000	$ 10,819,000
R&D credit	1,381,000	1,381,000
Capitalized R&D	6,788,000	0
Stock compensation	675,000	263,000
Accruals and other temporary differences	179,000	58,000
Gross deferred tax assets	22,148,000	12,521,000
Valuation allowance	(22,118,000)	(12,520,000)
Total deferred tax assets	30,000	1,000
Depreciation	(30,000)	(1,000)
Total deferred tax liabilities	(30,000)	(1,000)
Net deferred tax assets	$ 0	$ 0

Net Loss Per Share (Details) - shares	12 Months Ended
Net Loss Per Share (Details) - shares	Dec. 31, 2022	Dec. 31, 2021
Exercise of Stock Options
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share (in shares)	5,610,893	3,835,618

Subsequent Event (Details) $ in Millions	Dec. 31, 2022 USD ($)
Silicon Valley Bank
Subsequent Event [Line Items]
Cash	$ 1.8