AN2 Therapeutics (ANTX) 10-Q 9 Nov 23 2023 Q3 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	9 Months Ended
	Sep. 30, 2023	Nov. 02, 2023
Cover [Abstract]
Document Type	10-Q
Document Quarterly Report	true
Document Transition Report	false
Amendment Flag	false
Document Period End Date	Sep. 30, 2023
Document Fiscal Year Focus	2023
Document Fiscal Period Focus	Q3
Current Fiscal Year End Date	--12-31
Entity Registrant Name	AN2 Therapeutics, Inc.
Entity Central Index Key	0001880438
Entity File Number	001-41331
Entity Tax Identification Number	82-0606654
Entity Incorporation, State or Country Code	DE
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Shell Company	false
Entity Filer Category	Non-accelerated Filer
Entity Small Business	true
Entity Emerging Growth Company	true
Entity Ex Transition Period	false
Entity Address, Address Line One	1800 El Camino Real
Entity Address, Address Line Two	Suite D
Entity Address, City or Town	Menlo Park
Entity Address, State or Province	CA
Entity Address, Postal Zip Code	94027
City Area Code	650
Local Phone Number	331-9090
Title of 12(b) Security	Common Stock
Trading Symbol	ANTX
Security Exchange Name	NASDAQ
Entity Common Stock, Shares Outstanding		29,741,445

CONDENSED BALANCE SHEETS (Unaud

CONDENSED BALANCE SHEETS (Unaudited) - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022
Current assets:
Cash and cash equivalents	$ 32,616	$ 27,219
Short-term investments	91,202	68,840
Prepaid expenses and other current assets	2,591	2,509
Right-of-use asset, net		53
Total current assets	126,409	98,621
Long-term investments	26,356	3,219
Other assets, long-term	1,043	720
Total assets	153,808	102,560
Current liabilities:
Accounts payable	4,877	2,122
Accrued compensation	2,196	2,168
Accrued liabilities	6,790	2,837
Other current liabilities	973
Operating lease liabilities		53
Options subject to repurchase, short-term	3	6
Total current liabilities	14,839	7,186
Options subject to repurchase, long-term		2
Total liabilities	14,839	7,188
Commitments and contingencies (Note 7)
Stockholders' equity:
Preferred stock, $0.00001 par value; 10,000,000 shares authorized at September 30, 2023 and December 31, 2022; no shares issued and outstanding at September 30, 2023 and December 31, 2022
Common stock, $0.00001 par value; 500,000,000 shares authorized at September 30, 2023 and December 31, 2022; 29,741,445 and 19,402,658 shares issued and outstanding at September 30, 2023 and December 31, 2022, respectively
Additional paid-in capital	276,648	185,469
Accumulated other comprehensive loss	(122)	(374)
Accumulated deficit	(137,557)	(89,723)
Total stockholders' equity	138,969	95,372
Total liabilities and stockholders' equity	$ 153,808	$ 102,560

CONDENSED BALANCE SHEETS (Una_2

CONDENSED BALANCE SHEETS (Unaudited) (Parenthetical) - $ / shares	Sep. 30, 2023	Dec. 31, 2022
Statement of Financial Position [Abstract]
Preferred stock, par value	$ 0.00001	$ 0.00001
Preferred stock, shares authorized	10,000,000	10,000,000
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Common stock, par value	$ 0.00001	$ 0.00001
Common stock, shares authorized	500,000,000	500,000,000
Common stock, shares issued	29,741,445	19,402,658
Common stock, shares outstanding	29,741,445	19,402,658

CONDENSED STATEMENTS OF OPERATI

CONDENSED STATEMENTS OF OPERATIONS AND COMPREHENSIVE LOSS (Unaudited) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Operating expenses:
Research and development	$ 14,429	$ 7,428	$ 39,952	$ 19,759
Research and development - related party		1,000		1,000
General and administrative	3,751	3,342	10,868	9,027
Total operating expenses	18,180	11,770	50,820	29,786
Loss from operations	(18,180)	(11,770)	(50,820)	(29,786)
Other income, net	1,473	431	2,986	672
Net loss	(16,707)	(11,339)	(47,834)	(29,114)
Accretion to redemption value and cumulative dividends on preferred stock				(1,820)
Net loss attributable to common stockholders	$ (16,707)	$ (11,339)	$ (47,834)	$ (30,934)
Net loss per share attributable to common stockholders, basic	$ (0.65)	$ (0.59)	$ (2.22)	$ (2.21)
Net loss per share attributable to common stockholders, diluted	$ (0.65)	$ (0.59)	$ (2.22)	$ (2.21)
Weighted-average number of shares used in computing net loss per share, basic	25,645,421	19,347,148	21,532,537	13,987,862
Weighted-average number of shares used in computing net loss per share, diluted	25,645,421	19,347,148	21,532,537	13,987,862
Other comprehensive loss:
Unrealized gain (loss) on investments	$ (3)	$ (181)	$ 252	$ (514)
Comprehensive loss	$ (16,710)	$ (11,520)	$ (47,582)	$ (29,628)

CONDENSED STATEMENTS OF REDEEMA

CONDENSED STATEMENTS OF REDEEMABLE CONVERTIBLE PREFERRED STOCK AND STOCKHOLDERS' EQUITY (DEFICIT) (Unaudited) - USD ($) $ in Thousands	Total	At the Market Offering	Initial Public Offering	Underwritten Offering	Underwriters	Redeemable Convertible Preferred Stock	Common Stock	Common Stock At the Market Offering	Common Stock Initial Public Offering	Common Stock Underwritten Offering	Common Stock Underwriters	Additional Paid-in Capital	Additional Paid-in Capital At the Market Offering	Additional Paid-in Capital Initial Public Offering	Additional Paid-in Capital Underwritten Offering	Additional Paid-in Capital Underwriters	Accumulated Other Comprehensive Loss	Accumulated Deficit
Beginning balance at Dec. 31, 2021	$ (47,411)																$ (27)	$ (47,384)
Redeemable convertible preferred stock, Beginning balance at Dec. 31, 2021						$ 109,319
Redeemable convertible preferred stock, beginning balance, shares at Dec. 31, 2021						11,409,488
Beginning balance, shares at Dec. 31, 2021							2,730,298
Redeemable convertible preferred stock, Accretion to redemption value and cumulative dividends on preferred stock						$ 1,820
Accretion to redemption value and cumulative dividends on preferred stock	(1,820)											$ (437)						(1,383)
Redeemable convertible preferred stock, conversion of convertible preferred stock into common stock						$ (111,139)
Redeemable convertible preferred stock, conversion of convertible preferred stock into common stock, shares						(11,409,488)
Conversion of convertible preferred stock into common stock	111,139											111,139
Conversion of convertible preferred stock into common stock, shares							11,409,488
Issuance of common stock, net of commissions and offering costs			$ 60,836											$ 60,836
Issuance of common stock, net of commissions and offering costs, shares									4,600,000
Vesting of early exercised stock options	14											14
Repurchase of early exercised stock options	(11)											(11)
Repurchase of early exercised stock options, shares							(27,128)
Stock-based compensation	449											449
Unrealized gain (loss) on available-for-sale investments	(131)																(131)
Net loss	(7,655)																	(7,655)
Ending balances at Mar. 31, 2022	115,410											171,990					(158)	(56,422)
Ending balances, shares at Mar. 31, 2022							18,712,658
Beginning balance at Dec. 31, 2021	(47,411)																(27)	(47,384)
Redeemable convertible preferred stock, Beginning balance at Dec. 31, 2021						$ 109,319
Redeemable convertible preferred stock, beginning balance, shares at Dec. 31, 2021						11,409,488
Beginning balance, shares at Dec. 31, 2021							2,730,298
Net loss	(29,114)		(29,100)
Ending balances at Sep. 30, 2022	105,573											183,995					(541)	(77,881)
Ending balances, shares at Sep. 30, 2022							19,402,658
Beginning balance at Mar. 31, 2022	115,410											171,990					(158)	(56,422)
Beginning balance, shares at Mar. 31, 2022							18,712,658
Issuance of common stock, net of commissions and offering costs					$ 9,530											$ 9,530
Issuance of common stock, net of commissions and offering costs, shares											690,000
Vesting of early exercised stock options	3											3
Stock-based compensation	1,242											1,242
Unrealized gain (loss) on available-for-sale investments	(202)																(202)
Net loss	(10,120)																	(10,120)
Ending balances at Jun. 30, 2022	115,863											182,765					(360)	(66,542)
Ending balances, shares at Jun. 30, 2022							19,402,658
Vesting of early exercised stock options	2											2
Stock-based compensation	1,228											1,228
Unrealized gain (loss) on available-for-sale investments	(181)																(181)
Net loss	(11,339)																	(11,339)
Ending balances at Sep. 30, 2022	105,573											183,995					(541)	(77,881)
Ending balances, shares at Sep. 30, 2022							19,402,658
Beginning balance at Dec. 31, 2022	95,372											185,469					(374)	(89,723)
Beginning balance, shares at Dec. 31, 2022							19,402,658
Issuance of common stock under the ESPP	199											199
Issuance of common stock under the ESPP, Shares							23,794
Vesting of early exercised stock options	2											2
Stock-based compensation	2,068											2,068
Unrealized gain (loss) on available-for-sale investments	199																199
Net loss	(15,323)																	(15,323)
Ending balances at Mar. 31, 2023	82,517											187,738					(175)	(105,046)
Ending balances, shares at Mar. 31, 2023							19,426,452
Beginning balance at Dec. 31, 2022	$ 95,372											185,469					(374)	(89,723)
Beginning balance, shares at Dec. 31, 2022							19,402,658
Issuance of common stock upon the exercised of stock options, shares	15,000
Net loss	$ (47,834)		$ (47,800)
Ending balances at Sep. 30, 2023	$ 138,969											276,648					(122)	(137,557)
Redeemable convertible preferred stock, ending balance, shares at Sep. 30, 2023	0
Ending balances, shares at Sep. 30, 2023							29,741,445
Beginning balance at Mar. 31, 2023	$ 82,517											187,738					(175)	(105,046)
Beginning balance, shares at Mar. 31, 2023							19,426,452
Issuance of common stock, net of commissions and offering costs		$ 19,050											$ 19,050
Issuance of common stock, net of commissions and offering costs, shares								2,502,000
Vesting of early exercised stock options	2											2
Stock-based compensation	1,943											1,943
Unrealized gain (loss) on available-for-sale investments	56																56
Net loss	(15,804)																	(15,804)
Ending balances at Jun. 30, 2023	87,764											208,733					(119)	(120,850)
Ending balances, shares at Jun. 30, 2023							21,928,452
Issuance of common stock under the ESPP	167											167
Issuance of common stock under the ESPP, Shares							20,215
Issuance of common stock upon exercise of stock options	99											99
Issuance of common stock upon the exercised of stock options, shares							15,000
Issuance of common stock, net of commissions and offering costs				$ 65,479											$ 65,479
Issuance of common stock, net of commissions and offering costs, shares										7,777,778
Vesting of early exercised stock options	1											1
Stock-based compensation	2,169											2,169
Unrealized gain (loss) on available-for-sale investments	(3)																(3)
Net loss	(16,707)																	(16,707)
Ending balances at Sep. 30, 2023	$ 138,969											$ 276,648					$ (122)	$ (137,557)
Redeemable convertible preferred stock, ending balance, shares at Sep. 30, 2023	0
Ending balances, shares at Sep. 30, 2023							29,741,445

CONDENSED STATEMENTS OF REDEE_2

CONDENSED STATEMENTS OF REDEEMABLE CONVERTIBLE PREFERRED STOCK AND STOCKHOLDERS' EQUITY (DEFICIT) (Unaudited) (Parenthetical) - USD ($) $ in Millions	3 Months Ended
	Sep. 30, 2023	Jun. 30, 2023	Jun. 30, 2022	Mar. 31, 2022
At the Market Offering
Issuance costs		$ 0.9
Initial Public Offering
Issuance costs				$ 8.1
Underwritten Offering
Issuance costs	$ 4.5
Underwriters
Issuance costs			$ 0.8

CONDENSED STATEMENTS OF CASH FL

CONDENSED STATEMENTS OF CASH FLOWS (Unaudited) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022
Cash flows used in operating activities
Net Loss	$ (47,834)	$ (29,114)
Adjustments to reconcile net loss to net cash used in operating activities:
Stock-based compensation expense	6,180	2,919
Non-cash operating lease expense	53	57
Net accretion of discount on investments	(1,549)	(317)
Changes in operating assets and liabilities:
Prepaid expenses and other assets	(405)	(2,010)
Accounts payable	2,660	1,816
Accrued compensation	28	190
Accrued liabilities	3,727	692
Operating lease liabilities	(53)	(57)
Other current liabilities	973
Net cash used in operating activities	(36,220)	(25,824)
Cash flows from investing activities
Purchases of investments	(112,348)	(76,391)
Maturities of investments	68,650	48,565
Net cash used in investing activities	(43,698)	(27,826)
Cash flows from financing activities
Proceeds from issuance of common stock from the Underwritten Offering, net of commissions and offering expenses	65,800
Proceeds from issuance of common stock from the "at-the-market" offering, net of commissions and offering expenses	19,050
Proceeds from issuance of common stock under the ESPP	366
Proceeds from exercise of stock options	99
Proceeds from issuance of common stock from the initial public offering, net of underwriting discounts, commissions and offering expenses		70,366
Repurchase of early exercised stock options		(11)
Net cash provided by financing activities	85,315	70,355
Net increase in cash and cash equivalents	5,397	16,705
Cash and cash equivalents at the beginning of the period	27,219	12,097
Cash and cash equivalents at the end of the period	32,616	28,802
Supplemental disclosure of noncash financing items
Deferred offering costs included in accounts payable and accrued liabilities	$ 321
Conversion of redeemable convertible preferred stock into common stock		111,139
Accretion to redemption value and cumulative dividends on preferred stock		$ 1,820

Organization and Description of

Organization and Description of Business	9 Months Ended
	Sep. 30, 2023
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Organization and Description of Business	Note 1. Organization and Description of the Business Description of Business AN2 Therapeutics, Inc. (the “Company”) is a clinical-stage biopharmaceutical company focused on developing treatments for rare, chronic, and serious infectious diseases with high unmet needs. The Company’s initial product candidate, epetraborole, is under development in a pivotal Phase 2/3 clinical trial as a once-daily, oral treatment for patients with non-tuberculous mycobacterial (NTM) lung disease with an initial focus on treatment-refractory Mycobacterium avium complex (MAC) lung disease. The Company was incorporated in the state of Delaware in February 2017, began operations in November 2019, began trading on the Nasdaq Global Select Market on March 25, 2022 under the symbol “ANTX”, and is based in Menlo Park, California. Since launching operations in November 2019, the Company has devoted substantially all of its resources to performing research and development activities, including with respect to its initial product candidate, epetraborole, business planning, hiring personnel, raising capital, and providing general and administrative support for these operations. Initial Public Offering On March 24, 2022, the Company’s registration statement on Form S-1 (File No. 333-263295) relating to its initial public offering (“IPO”) of common stock became effective. The IPO closed on March 29, 2022, at which time the Company issued an aggregate of 4,600,000 shares of its common stock at a price to the public of $ 15.00 per share. In addition, immediately prior to the closing of the IPO, all outstanding shares of the Company’s redeemable convertible preferred stock automatically converted into 11,409,488 shares of common stock. The aggregate offering proceeds for shares sold in the IPO was $ 69.0 million. After deducting underwriting discounts and commissions of $ 4.8 million and offering costs paid or payable by the Company of $ 3.3 million, the net proceeds from the offering were approximately $ 60.9 million. On April 8, 2022, the underwriters from the IPO exercised an option to purchase 690,000 additional shares of the Company's common stock at a public offering price of $ 15.00 per share, resulting in additional gross proceeds to the Company of $ 10.4 million, and additional net proceeds of approximately $ 9.5 million. After giving effect to this exercise of the overallotment option, the total number of shares sold by the Company in the IPO increased to 5,290,000 shares with total net proceeds to the Company of approximately $ 70.4 million. At-The-Market Offering On April 6, 2023, the Company entered into a sales agreement ("Sales Agreement") with Cowen and Company, LLC as the Company’s sales agent (“Agent”) to issue and sell up to an aggregate gross sales of $ 100.0 million in shares ( “Shares”) of the Company’s common stock through an “at-the-market” equity offering program (“ATM Offering” ). The Company will pay commissions to the Agent of up to 3.0 % of the gross proceeds of the sale of the Shares sold under the Sales Agreement and reimburse the Agent for certain expenses. During the nine months ended September 30, 2023 , the Company issued and sold 2,502,000 shares of common stock under the ATM Offering, resulting in net proceeds of $ 19.1 million, after deducting commissions and other offering costs. Underwritten Offering On August 15, 2023, the Company entered into an underwriting agreement (the "Underwriting Agreement") with Cowen and Company, LLC, Leerink Partners LLC and Evercore Group L.L.C. as representatives of several underwriters to issue and sell 7,777,778 shares of common stock at an offering price of $ 9.00 per share, resulting in net proceeds of $ 65.5 million, after deducting commissions and other offering costs (the "Underwritten Offering").

Basis of Presentation and Summa

Basis of Presentation and Summary of Significant Accounting Policies	9 Months Ended
	Sep. 30, 2023
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	Note 2. Basis of Presentation and Summary of Significant Accounting Policies Basis of Presentation The Company’s financial statements have been prepared in accordance with United States generally accepted accounting principles (“U.S. GAAP”). For all periods presented, shares of common stock and then existing redeemable convertible preferred stock and per share amounts have been adjusted on a retroactive basis to reflect our 2.352936 -for-1 forward stock split , which was effected on March 18, 2022. The stock split did not change the par value of the common stock and redeemable convertible preferred stock or the authorized number of shares of common stock and redeemable convertible preferred stock. Unaudited Interim Condensed Financial Information The accompanying condensed balance sheet as of September 30, 2023, the condensed statements of operations and comprehensive loss and the condensed statements of redeemable convertible preferred stock and stockholders’ equity for the three and nine months ended September 30, 2023 and 2022, and the condensed statements of cash flows for the nine months ended September 30, 2023 and 2022 are unaudited. The unaudited interim condensed financial statements have been prepared on the same basis as the audited annual financial statements and, in the opinion of management, reflect all adjustments, which include only normal recurring adjustments, necessary for the fair statement of the Company’s financial position as of September 30, 2023 and the results of its operations and its cash flows for the nine months ended September 30, 2023 and 2022. The financial data and other information disclosed in these notes related to the nine months ended September 30, 2023 and 2022 are also unaudited. The results for the nine months ended September 30, 2023 are not necessarily indicative of results to be expected for the year ending December 31, 2023, any other interim periods, or any future year or period. The balance sheet as of December 31, 2022 included herein was derived from the audited financial statements as of that date. Certain disclosures have been condensed or omitted from the interim condensed financial statements. Accordingly, these unaudited interim condensed financial statements should be read in conjunction with the Company’s audited financial statements as of and for the year ended December 31, 2022, which are included in the Company’s Annual Report on Form 10-K, as filed with the U.S. Securities and Exchange Commission (“SEC”), dated March 29, 2023. Risks and Uncertainties Liquidity Prior to the Company’s IPO in March 2022, the Company’s operations had historically been financed through the issuance of redeemable convertible preferred stock. Since inception, the Company has incurred significant losses and negative net cash flows from operations. During the nine months ended September 30, 2023 and 2022, the Company incurred a net loss of $ 47.8 million and $ 29.1 million, respectively, and had cash flows used in operating activities of $ 36.2 million and $ 25.8 million, respectively. The Company has an accumulated deficit of $ 137.6 million and $ 89.7 million as of September 30, 2023 and December 31, 2022, respectively, and will require substantial additional capital for research and development activities. The Company anticipates incurring additional losses until such time, if ever, that it can generate significant sales of its product candidate currently in development. As of September 30, 2023, the Company had cash and cash equivalents, short-term investments and long-term investments of $ 150.2 million. Management believes that its cash, cash equivalents and investments as of September 30, 2023 will be sufficient to fund its current operating plan through at least 12 months from the issuance date of these condensed financial statements. Future capital requirements will depend on many factors, including the timing and extent of spending on research and development, including costs for preclinical and nonclinical studies, clinical trials and clinical trial, registration and pre-registration material manufacturing. There can be no assurance that, in the event the Company requires additional financing, such financing will be available at terms acceptable to the Company, if at all. Failure to generate sufficient cash flows from operations, raise additional capital, and reduce discretionary spending should additional capital not become available could have a material adverse effect on the Company’s ability to achieve its intended business objectives. Other Risks and Uncertainties Although the public health effects of the COVID-19 pandemic have subsided and the public-health emergency has ended, we continue to observe lingering impacts in the form of staffing shortages at clinical sites, which may have caused and continue to cause delays in activating sites and screening and enrolling patients. Because of the above and other factors, along with global market and macroeconomic fluctuations and global conflicts, our results of operations may vary substantially from year to year and from quarter to quarter and, as a result, we believe that period to period comparisons of our operating results may not be meaningful and should not be relied upon as being indicative of our future performance. For more information on the risks and uncertainties associated with the evolving effects of macroeconomic headwinds and the COVID-19 pandemic on our business and our clinical development and regulatory efforts, see “Part II Item 1A—Risk Factors.” Segments The Company operates and manages its business as one reportable and operating segment. The Company’s chief executive officer, who is the chief operating decision maker, reviews financial information on a company-wide basis for purposes of allocating resources and assessing financial performance. Use of Estimates The preparation of financial statements in conformity with U.S. GAAP requires management to make estimates and judgments that affect the reported amounts of assets and liabilities and disclosures of contingent assets and liabilities as of the date of the financial statements and the reported amounts of expenses during the reporting period. On an ongoing basis, management evaluates its estimates, including those related to research and development accruals, fair value of assets and liabilities and stock-based compensation. Management bases its estimates on historical experience and on various other market-specific and relevant assumptions that management believes to be reasonable under the circumstances. Actual results could differ from those estimates. Deferred Offering Costs The Company capitalizes certain legal, accounting and other third-party fees that are directly related to the Company’s equity financings, including its Underwritten Offering in August 2023, shelf offering and ATM Offering filed in April 2023 and its IPO in 2022, until such financings are consummated. After consummation of the equity financing, these costs are recorded as a reduction of the proceeds received as a result of the financing. The Company capitalized certain legal, accounting and other third-party fees that were directly related to the Company’s Underwritten Offering, ATM Offering and IPO. After the completion of the IPO in March 2022, the total deferred offering costs of $ 3.3 million were offset against the proceeds from the IPO and reclassified to additional paid-in capital in the accompanying condensed balance sheets. After the completion of the ATM Offering in June 2023, the total deferred offering costs of $ 0.9 million were offset against the proceeds from the ATM Offering and reclassified to additional paid-in capital in the accompanying condensed balance sheets. After the completion of the Underwritten Offering in August 2023, the total deferred offering costs of $ 4.5 million were offset against the proceeds from the Underwritten Offering and reclassified to additional paid-in capital in the accompanying condensed balance sheets. At September 30, 2023 and December 31, 2022 , no deferred offering costs were included as non-current assets in the accompanying balance sheets. Research and Development Expenses All research and development costs, including work performed by third parties, are expensed as incurred. Research and development costs consist of salaries and other personnel-related expenses, including associated stock-based compensation, consulting fees, and facility costs, as well as fees paid to other entities that conduct certain research and development activities on behalf of the Company. Payments made prior to the receipt of goods or services to be used in research and development are capitalized until the goods are received or services are rendered. As part of the process of preparing its financial statements, the Company estimates its accrued expenses. This process involves reviewing quotations and contracts, identifying services that have been performed on the Company’s behalf and estimating the level of services performed and the associated cost incurred for services for which the Company has not yet been invoiced or otherwise notified of the actual cost. The majority of the Company’s service providers invoice monthly in arrears for services performed or when contractual milestones are met. The Company makes estimates of its accrued expenses at the end of each reporting period based on the facts and circumstances known to the Company at that time. The significant estimates in the Company’s accrued research and development expenses relate to expenses incurred with respect to contract manufacturing and clinical and other research organizations, academic research centers and other vendors in connection with research and development activities for which the Company has not yet been invoiced. Redeemable Convertible Preferred Stock The Company recorded the redeemable convertible preferred stock at fair value on the dates of issuance, net of issuance costs. The carrying value of the redeemable convertible preferred stock was accreted to its redemption value. Immediately prior to the closing of the IPO, all outstanding shares of the Company’s redeemable convertible preferred stock were converted into shares of common stock and the related carrying value was reclassified to common stock and additional paid-in capital. There were no shares of redeemable convertible preferred stock outstanding as of September 30, 2023 . Stock-Based Compensation The Company measures and recognizes compensation expense for equity-classified stock-based awards made to employees, directors and non-employees based on the grant date estimated fair value of each award. Compensation expense for employee and director awards is recognized on a straight-line basis over the requisite service period which is generally the vesting period for the entire award. Expense is adjusted for forfeitures as they occur. Compensation expense for non-employee awards is recognized in the same period and manner as if the Company had paid cash for the goods or services provided. The valuation model used for calculating the fair value of stock options for stock compensation expense is the Black-Scholes option-pricing model (the Black-Scholes model). The Black-Scholes model requires management to make assumptions and judgments about the variables used in the calculation, including the expected term, the expected volatility of common stock, an assumed risk-free interest rate, and expected dividends the Company may pay. Management elected to apply the practical expedient for private companies and used the simplified method to determine the awards’ expected term. Volatility is based on an average of the historical volatilities of the common stock of entities with c haracteristics similar to the Company’s. The risk-free rate is based on the U.S. Treasury yield curve in effect at the time of grant for periods corresponding with the expected life of the option. The Company uses an assumed dividend yield of zero as the Company has never paid dividends and has no current plans to pay any dividends on its common stock. For option awards that contain performance conditions, compensation cost is recognized in the period in which it becomes probable that the performance condition will be satisfied. For option awar ds that vest upon a liquidity event or a change in control, the performance condition is not probable of being achieved until the event occurs. As a result, no compensation expense would be recognized until the performance-based vesting condition is achieved. Fair Value of Common Stock Prior to the Company's IPO, the absence of an active market for the Company’s common stock required the Company’s board of directors (“Board”) to determine the fair value of its common stock for purposes of granting stock options. The fair value of the Company’s common stock was determined by the Company’s Board with assistance from management and an independent third-party valuation firm. Management’s approach to estimating the fair value of the Company’s common stock was consistent with the methods outlined in the American Institute of Certified Public Accountants’ Practice Aid, Valuation of Privately-Held- Company Equity Securities Issued as Compensation . Determining the best estimated fair value of the Company’s common stock requires significant judgment and management considers several factors, including the Company’s stage of development, equity market conditions affecting comparable public companies, significant milestones and progress in research and development efforts. Since the completion of its IPO, the Company uses its stock price traded on the Nasdaq Global Select Market to determine the fair value of its common stock. Cash and Cash Equivalents The Company considers all highly liquid investments with a maturity of three months or less when purchased to be cash equivalents. Cash equivalents, which consist of money market funds, corporate debt securities and corporate commercial paper, are stated at fair value. As of September 30, 2023 and December 31, 2022, the Company had cash and cash equivalents of $ 32.6 million and $ 27.2 million, respectively. Investments Investments consist of U.S. Treasury securities, commercial paper, and U.S. Government agency securities. All of the Company’s investments are classified as available-for-sale and are carried at estimated fair values and reported in cash equivalents, short-term investments or long-term investments. Management determines the appropriate classification of the investments at the time they are acquired and evaluates the appropriateness of such classifications at each balance sheet date. Investments with contractual maturities greater than 12 months are considered long-term investments. The cost of investments sold, if any, is based on the specific identification method. Unrealized gains and losses on available-for-sale investments are reported in accumulated other comprehensive gain (loss) as a separate component of stockholders’ equity. For available-for-sale debt securities in an unrealized loss position, the Company first assesses whether it intends to sell, or it is more likely than not that it will be required to sell the security before recovery of its amortized cost basis. If either of the criteria regarding intent or requirement to sell is met, the security’s amortized cost basis is written down to fair value and recognized in other income (expense) in the statements of operations and comprehensive loss. If neither criterion is met, the Company evaluates whether the decline in fair value is related to credit-related factors or other factors. In making this assessment, management considers the extent to which fair value is less than amortized cost, any changes to the rating of the security by a rating agency, and adverse conditions specifically related to the security, among other factors. Credit-related impairment losses, limited by the amount that the fair value is less than the amortized cost basis, are recorded through an allowance for credit losses in other income (expense), net. Any unrealized losses from declines in fair value below the amortized cost basis as a result of non-credit factors are recognized in accumulated other comprehensive income (loss) as a separate component of stockholders’ equity, along with unrealized gains. Realized gains and losses and declines in fair value, if any, on available-for-sale securities are included in other income (expense) in the statements of operations and comprehensive loss. For purposes of identifying and measuring credit-related impairments, the Company’s policy is to exclude applicable accrued interest from both the fair value and amortized cost basis of the related security. The Company has elected to write-off uncollectible accrued interest receivable balances in a timely manner, which is defined by the Company as when interest due becomes 90 days delinquent. The accrued interest write-off will be recorded by reversing interest income. Accrued interest receivable is recorded to prepaid expenses and other current assets. As of September 30, 2023 and December 31, 2022, the Company had investments of $ 117.6 million and $ 72.1 million, respectively. Cloud Computing Arrangements The Company incurs costs to implement cloud computing arrangements (“CCA”) that are hosted by third-party vendors. Implementation costs incurred during the application development stage are considered for capitalization until the software is ready for its intended use. Once capitalized, these costs are then amortized on a straight-line basis over the term of the associated hosting arrangement and are recognized as an operating expense within the statements of operations and comprehensive loss. As of September 30, 2023 , the Company has no t capitalized any CCA implementation costs or amortized any such costs. Concentrations of Credit Risk Financial instruments that potentially subject the Company to concentrations of credit risk consist of cash, cash equivalents and investments. The Company’s cash is invested through financial institutions in the United States. The Company’s investments consist of debt securities, issued by highly rated corporate entities or the U.S. government. The Company’s exposure to any individual corporate entity is limited by its investment policy. Deposits may at times exceed federally insured limits, but minimal credit risk exists. The Company invests its cash equivalents in highly rated money market funds. The Company has not experienced any credit losses in such accounts and does not believe it is exposed to any significant credit risk on these funds. The Company is exposed to credit risk in the event of a default by the financial institutions holding its cash to the extent recorded on the condensed balance sheets. In March 2023, one of the financial institutions utilized by the Company was closed by the California Department of Financial Protection and Innovation, which appointed the Federal Deposit Insurance Corporation as receiver. Through September 30, 2023 , the Company had no off-balance sheet concentrations of credit risk. Government Contract In September 2022, the Company received a cost-reimbursement contract award under which the Company is eligible to receive up to $ 17.8 million from the U.S. National Institute of Allergy and Infection Diseases (“NIAID”) to support preclinical, Phase 1 studies and other activities to enable advancement of epetraborole into late-stage development for acute systemic melioidosis and other biothreat pathogens. This project will be funded in whole or in part with Federal funds from the National Institute of Allergy and Infectious Diseases, National Institutes of Health, Department of Health and Human Services, under Contract No. 75N93022C00059. Accounting for this contract does not fall under ASC 606, Revenue from Contracts with Customers, as NIAID will not benefit directly from the advancement of epetraborole. As there is no authoritative guidance under U.S. GAAP on accounting for government assistance to for-profit business entities, the Company applied International Accounting Standards (IAS) 20, Accounting for Government Grants and Disclosure of Government Assistance, by analogy when accounting for the NIAID contract payments to the Company. Under IAS 20, government contract proceeds are recognized when there is reasonable assurance the conditions of the contract will be met and the contract funding will be received. For the NIAID contract, this occurs after the qualifying expenses related to the contract have been incurred, or the Company concludes the conditions of the contract have been substantially met. The income related to the reimbursement of operating expenses is then recorded as a reduction of those expenses (see Note 4—Funding Arrangements). Grant Agreements In September 2022, the Company entered into a subcontract agreement with the University of Georgia Research Foundation (“UGARF”) to conduct preclinical activities. The Company is eligible to receive up to $ 1.4 million from UGARF to support preclinical development of a boron-containing small molecule for Chagas disease. In September 2023, the Company entered into a grant agreement with the Bill and Melinda Gates Foundation (“BMGF”) to fund up to $ 1.8 million to generate new boron-based lead compounds with the potential to be developed into drugs that treat tuberculosis and malaria. The Company recognizes grant proceeds in accordance with ASC 958-605, Revenue Recognition Not-for-Profit Entities, when qualifying costs are incurred and conditions of the grant agreement have been met. When receipt of grant proceeds is reasonably assured, the Company records a reduction to the research and development expenses incurred and a corresponding grant receivable. Cash received from grants in advance of incurring qualifying costs is recorded as a liability and recognized as a reduction to the qualifying research and development expenses incurred (see Note 4—Funding Arrangements). Comprehensive Loss Comprehensive loss includes net loss and certain changes in stockholders’ equity that are excluded from net loss. The Company’s other comprehensive loss consists of net changes in unrealized gains and losses on its available-for-sale investments. For the nine months ended September 30, 2023 and 2022, the Company had $ 0.3 million of net unrealized gain and $ 0.5 million of net unrealized loss , respectively, on available-for-sale investments. Net Loss Per Share Basic net loss per share attributable to common stockholders is calculated by dividing the net loss attributable to common stockholders by the weighted-average number of shares of common stock outstanding during the period, without consideration for potentially dilutive securities. Diluted net loss per share attributable to common stockholders is computed by dividing the net loss attributable to common stockholders by the weighted-average number of common stock and potentially dilutive securities outstanding for the period. For purposes of the diluted net loss per share calculation, redeemable convertible preferred stock, stock options, common stock subject to repurchase related to unvested early exercise of stock options are considered to be potentially dilutive securities. Basic and diluted net loss attributable to common stockholders per share is presented in conformity with the two-class method required for participating securities as the redeemable convertible preferred stock is considered a participating security because it participates in dividends with common stock, and is accreted to redemption. The Company also considers the shares issued upon the early exercise of stock options subject to repurchase to be participating securities because holders of such shares have non-forfeitable dividend rights in the event a dividend is paid on common stock. The holders of all series of redeemable convertible preferred stock and the holders of early exercised shares subject to repurchase do not have a contractual obligation to share in the Company’s losses. As such, the net loss was attributed entirely to common stockholders. Because the Company has reported a net loss for all periods presented, diluted net loss per share is the same as basic net loss per share for those periods because the impact of potentially dilutive securities would be anti-dilutive. JOBS Act Accounting Election The Company is an emerging growth company, as defined in the Jumpstart Our Business Startups Act of 2012 (the “JOBS Act”). Under the JOBS Act, emerging growth companies can delay adopting new or revised accounting standards issued subsequent to the enactment of the JOBS Act until such time as those standards apply to private companies. The Company has elected to use this extended transition period for complying with new or revised accounting standards that have different effective dates for public and private companies until the earlier of the date the Company (i) is no longer an emerging growth company or (ii) affirmatively and irrevocably opts out of the extended transition period provided in the JOBS Act. The Company may take advantage of these provisions for up to five years (which is through March 2027), unless the Company ceases to be an emerging growth company at an earlier date. As a result, these financial statements may not be comparable to companies that comply with new or revised accounting pronouncements as of public company effective dates. Recently Adopted Accounting Pronouncements In July 2018, the FASB issued ASU No. 2018-11, Leases (Topic 842): Targeted Improvements (“ASU 2018-11”). ASU 2018-11 provided an alternative method in addition to the modified retrospective transition method for ASU No. 2016-02, Leases: Amendments to the FASB Accounting Standards Codification (“ASU 2016-02”), issued in February 2016. Under ASU 2018-11, an entity may elect to initially apply the new lease standard at the adoption date and recognize a cumulative-effect adjustment to the opening balance of retained earnings in the period of adoption. Under ASU 2016-02, a lease is required to recognize assets and liabilities with lease terms of more than twelve months. ASU 2016-02 is effective for nonpublic business entities and public entities eligible to be Smaller Reporting Companies for fiscal years beginning after December 15, 2021. The Company adopted the new standard on January 1, 2022 using the modified retrospective approach. The Company has elected to apply the transition method that allows companies to continue applying the guidance under the lease standard in effect at that time in the comparative periods presented in the condensed financial statements and recognize a cumulative-effect adjustment to the opening balance of accumulated deficit on the date of adoption. The Company has elected to combine lease components (e.g., fixed rent payments) with non-lease components (e.g., common-area maintenance costs) on its facility and clinical research organization (“CRO”) embedded lease asset classes. The Company also elected the “package of practical expedients”, which permits the Company not to reassess under the new standard the Company’s prior conclusions about lease identification, lease classification and initial direct costs. The Company also elected the short-term lease practical expedients allowed under the standard. Lastly, the Company did not elect the practical expedient allowing the use-of-hindsight which would require the Company to reassess the lease term of its leases based on all facts and circumstances through the effective date. Results for reporting period beginning after January 1, 2022 are presented under the new standard, while prior period amounts are not adjusted and continue to be reported under the accounting standards in effect for the prior period. Upon adoption of the new lease standard, on January 1, 2022, the Company capitalized operating lease right-of-use (ROU) assets of $ 0.05 million and $ 0.05 million of operating lease liabilities, within the condensed balance sheets upon adoption. In November 2021, the FASB issued ASU No. 2021-10, Government Assistance (Topic 832) Disclosures by Business Entities about Government Assistance. Current U.S. GAAP has no specific authoritative guidance on the accounting for, or the disclosure of, government assistance received by business entities. The amendments in this update improve financial reporting by requiring disclosures that increase the transparency of transactions with a government accounted for by applying a grant or contribution accounting model by analogy, including the types of transactions, the accounting for those transactions, and the effect of those transactions on an entity’s financial statements. The amendments in this update require the following annual disclosures about transactions with a government that are accounted for by applying a grant or contribution accounting model by analogy, including: (1) information about the nature of the transactions and the related accounting policy used to account for the transactions; (2) the line items on the balance sheet and income statement that are affected by the transactions, and the amounts applicable to each financial statement line item; and (3) the significant terms and conditions of the transactions, including commitments and contingencies. The amendments in this update are effective for all entities within their scope for financial statements issued for annual periods beginning after December 15, 2021. Early application of the amendments is permitted. The Company adopted this update during the quarter ended September 30, 2022 and accounted for the NIAID contract in accordance with this update. In August 2018, the FASB issued ASU 2018-15, “Intangibles—Goodwill and Other—Internal-Use Software (Subtopic 350-40): Customer’s Accounting for Implementation Costs Incurred in a Cloud Computing Arrangement That Is a Service Contract (a consensus of the FASB Emerging Issues Task Force)”. This update is intended to guide entities in evaluating the accounting for fees paid by a customer in a cloud computing arrangement by providing guidance for determining when the arrangement includes a software license. This standard was effective for financial statements issued by public companies for annual and interim periods beginning after December 15, 2019, and effective for financial statements issued by non-public entities for annual periods beginning after December 15, 2020. The Company adopted this standard beginning July 1, 2022 , noting that this standard was applied prospectively. Adoption of this standard did not have a material impact on the Company's condensed financial statements. In June 2016, the FASB issued ASU No. 2016-13, Financial Instruments—Credit Losses (Topic 326) Measurement of Credit Losses on Financial Instruments (“ASU 2016-13”), which requires an entity to utilize a new impairment model known as the current expected credit loss (“CECL”) model to estimate its lifetime “expected credit loss” and record an allowance that, when deducted from the amortized cost basis of the financial assets and certain other instruments, including but not limited to available-for-sale debt securities. Credit losses relating to available-for-sale debt securities will be recorded through an allowance for credit losses rather than as a direct write-down to the security. ASU 2016-13 requires a cumulative effect adjustment to the balance sheet as of the beginning of the first reporting period in which the guidance is effective. In November 2019, the FASB issued ASU 2019-10, Financial Instruments—Credit Losses (Topic 326), Derivatives and Hedging (Topic 815) and Leases (Topic 842): Effective Dates, which defers the effective date of ASU 2016-13 to fiscal years beginning after December 15, 2022 for SEC reporting companies that are smaller reporting companies such as the Company. The Company adopted this standard beginning January 1, 2023 . Adoption of this standard did not have a material impact on the Company's condensed financial statements. Recent Accounting Pronouncements Not Yet Adopted From time to time, new accounting pronouncements are issued by the FASB or other standard setting bodies and adopted by the Company as of the specified effective date. Unless otherwise noted, the Company believes that the impact of recently issued standards that are not yet effective will not have a material impact on its condensed financial statements and disclosures. As an “emerging growth” company, it has been the Company’s intention to take advantage of certain temporary exemption

Fair Value Measurements

Fair Value Measurements	9 Months Ended
	Sep. 30, 2023
Fair Value Disclosures [Abstract]
Fair Value Measurements	Note 3. Fair Value Measurements The Company adopted ASU 2016-13 beginning January 1, 2023. The Company records certain financial assets and liabilities at fair value. The accounting guidance for fair value provides a framework for measuring fair value, clarifies the definition of fair value, and expands disclosures regarding fair value measurements. Fair value is defined as the price that would be received to sell an asset or paid to transfer a liability (an exit price) in an orderly transaction between market participants at the reporting date. The accounting guidance establishes a three-tiered hierarchy, which prioritizes the inputs used in the valuation methodologies in measuring fair value as follows: • Level 1: Inputs which include quoted prices in active markets for identical assets and liabilities. • Level 2: Inputs other than Level I that are observable, either directly or indirectly, such as quoted prices for similar assets or liabilities; quoted prices in markets that are not active; or other inputs that are observable or can be corroborated by observable market data for substantially the full term of the assets or liabilities. • Level 3: Unobservable inputs that are supported by little or no market activity and that are significant to the fair value of the assets or liabilities. The Company’s primary financial instruments include cash, cash equivalents, short-term investments and long-term investments, prepaid expenses, accounts payable, and accrued liabilities. The carrying amounts of the Company’s financial instruments, other than cash equivalents, short- and long-term investments, approximate fair value due to their relatively short maturities. The following table presents the Company’s financial assets, which consist of cash equivalents and investments classified as available-for-sale investments, that are measured at fair value on a recurring basis (in thousands): September 30, 2023 Level Amortized Cost Unrealized Gain Unrealized Loss Estimated Fair Value Cash equivalents: Money market funds Level 1 $ 22,040 $ — $ — $ 22,040 Short-term investments: U.S. Treasury securities Level 1 13,569 — ( 6 ) 13,563 U.S. Government agency securities Level 2 23,315 6 ( 22 ) 23,299 Commercial paper Level 2 40,887 — ( 66 ) 40,821 Asset-backed securities Level 2 8,659 — ( 20 ) 8,639 Corporate debt securities Level 2 4,881 — ( 1 ) 4,880 Long-term investments: U.S. Treasury securities Level 1 21,369 — ( 15 ) 21,354 U.S. Government agency securities Level 2 5,000 2 — 5,002 Total $ 139,720 $ 8 $ ( 130 ) $ 139,598 December 31, 2022 Level Amortized Cost Unrealized Gain Unrealized Loss Estimated Fair Value Cash equivalents: Money market funds Level 1 $ 10,152 $ — $ — $ 10,152 Short-term investments: U.S. Treasury securities Level 1 29,381 — ( 213 ) 29,168 Commercial paper Level 2 27,701 2 ( 82 ) 27,621 U.S. Government agency securities Level 2 12,126 4 ( 79 ) 12,051 Long-term investments: — U.S. Treasury securities Level 1 1,224 — ( 1 ) 1,223 U.S. Government agency securities Level 2 2,001 — ( 5 ) 1,996 Total $ 82,585 $ 6 $ ( 380 ) $ 82,211 The Company classifies its money market funds and U.S. Treasury securities, which are valued based on quoted market prices in active markets with no valuation adjustment, as Level 1 assets within the fair value hierarchy. The Company classifies its investments in commercial paper and U.S. government agency securities as Level 2 within the fair value hierarchy. The fair values of these investments are estimated by taking into consideration valuations obtained from third-party pricing services. The pricing services utilize industry standard valuation models, including both income- and market-based approaches, for which all significant inputs are observable, either directly or indirectly, to estimate fair value. These inputs include reported trades of and broker/dealer quotes on the same or similar securities, issuer credit spreads, benchmark securities, prepayment/default projections based on historical data and other observable inputs. There were no transfers of financial instruments between valuation levels during the nine months ended September 30, 2023. As of September 30, 2023 , no ne of the Company’s available-for-sale investments that were in an unrealized loss position had been in an unrealized loss position for more than 12 months. During the nine months ended September 30, 2023 and 2022 , the Company did no t sell any available-for-sale investments. The Company’s short-term investments had maturities of less than one year from the balance sheet date. The Company’s long-term investments had maturities of between one and two years from the balance sheet date. The Company does not intend to sell the securities in an unrealized loss position and does not expect they will be required to sell the securities before recovery of the unamortized cost basis. Additionally, the Company evaluated its securities for credit losses and considered the decline in market value to be primarily attributable to current economic and market conditions and not credit related. Accordingly, no allowance for credit losses has been recognized as of September 30, 2023 and December 31, 2022. During the nine months ended September 30, 2023 and 2022 , the Company did no t recognize any impairment losses related to investments. As of September 30, 2023 and December 31, 2022 , the Company had accrued interest receivable of $ 0.5 million and $ 0.2 million, respectively, which was included in prepaid expenses and other current assets on the balance sheets.

Funding Arrangements

Funding Arrangements	9 Months Ended
	Sep. 30, 2023
Funding Arrangements [Abstract]
Funding Arrangements	Note 4. Funding Arrangements NIAID Contract In September 2022, the Company received a cost-reimbursement contract award from the NIAID (“NIAID Agreement” ) to support preclinical, Phase 1 studies and other activities to enable the advancement of epetraborole into late-stage development for acute systemic melioidosis and other biothreat pathogens. The Company can receive up to $ 17.8 million in funding over a total term of up to 48 months , consisting of a base period and seven option periods. In July 2023, the NIAID exercised one of seven available options under the NIAID contract (No: 75N93022C00059), resulting in an increase in committed contract funding of $ 0.7 million, for a total of $ 5.0 million. Funding for this option extends the estimated completion of the contract by 13 months beyond the base period of 18 months (April 2025). The Company has no t recognized any income related to the reimbursement of operating expenses under this agreement during the three and nine months ended September 30, 2023. UGARF Grant In September 2022, the Company entered into a subcontract agreement with the UGARF to conduct preclinical activities on behalf of UGARF (“UGARF Agreement”). UGARF reimburses the Company under an award from The Wellcome Trust. The Company is eligible to receive up to $ 1.4 million from UGARF to support preclinical development of a boron-containing small molecule for Chagas disease. As of September 30, 2023, the Company had recorded a grant receivable of $ 0.4 million which was included in prepaid expenses and other current assets on the balance sheets. During the three and nine months ended September 30, 2023 , the Company recorded income of $ 0.4 million and $ 0.7 million, respectively, as reductions in research and development operating expenses under the UGARF agreement. BMFG Grant In September 2023, the Company received a cost-reimbursement contract award from the Bill and Melinda Gates Foundation (“BMGF Agreement”) under which the Company was awarded $ 1.8 million to support the discovery of novel, boron containing small molecules for the treatment of tuberculosis and malaria. The Company is required to apply the funds it receives under the BMGF Agreement solely toward direct costs related to this research program. The Company received $ 1.0 million of funding in advance and tracks and reports eligible expenses incurred to the BMGF. Any unspent funds and any funds spent that have not yet been incurred are recorded as part of other current liabilities on the balance sheets. As of September 30, 2023, the Company had recorded $ 1.0 million to other current liabilities. During the three and nine months ended September 30, 2023, the Company recorded income of $ 24 thousand as a reduction in research and development operating expenses under the BMGF agreement.

Collaboration and License Agree

Collaboration and License Agreements	9 Months Ended
	Sep. 30, 2023
Collaboration And License Agreements [Abstract]
Collaboration and License Agreements	Note 5 . Collaboration and License Agreements Anacor Licensing Agreement In November 2019, the Company entered into an exclusive worldwide license agreement with Anacor Pharmaceuticals, Inc. (“Anacor”) for certain compounds and other intellectual property controlled by Anacor for the treatment, diagnosis, or prevention of all human diseases (the “Anacor License”). The Anacor License will expire upon expiration of the last to expire royalty term. Either party may terminate the Anacor License for the other party’s material breach following a cure period or immediately upon certain insolvency events relating to the other party. The Company has the right to terminate the agreement at its convenience upon 90-day written notice until the first regulatory approval or one-year notice thereafter. Furthermore, upon termination of the Anacor License for any of the foregoing reasons, the rights and licenses within will terminate. In exchange for the worldwide, sublicensable, exclusive right and licenses to develop, manufacture, and commercialize the specified compounds, the Company paid Anacor a non-refundable $ 2.0 million upfront payment and granted Anacor shares of Series A redeemable convertible preferred stock. The Company agreed to make further payments to Anacor upon achievement of various development milestones for an aggregate maximum of $ 2.0 million, upon achievement of various commercial and sales threshold milestones for an aggregate maximum payment of $ 125.0 million, and up to 50 % of royalties received under certain sublicensing arrangements. Royalties are subject to certain customary reductions, including lack of patent coverage and generic product entry. The Company also agreed to pay Anacor non-refundable, non-creditable sales royalties on a tiered marginal royalty rate based on the country’s status as a developing or developed country as defined in the license agreement. Sales royalties are a percentage of net sales, as specified in the Anacor License, and range from mid-single digits for developing countries (as classified by the World Bank) and single to mid-teens for all other countries or the China, Hong Kong, Taiwan and Macau territories, upon reaching a minimum of net sales in the low-teen millions. The sales royalties are required to be paid on a product-by-product and country-by-country basis, until the latest to occur of 15 years following the date of first commercial sale of a product, the expiration of all regulatory or data exclusivity, or the date upon of the expiration of the last to expire valid claim of a licensed patent covering such product in such country. Currently, the date of the expiration of the last to expire valid claim of a licensed patent covering epetraborole in the licensed territory is June 2028. In addition, Anacor is entitled to certain milestone payments upon a change of control of the Company. In December 2021, the Company entered into an amendment to the Anacor License for certain compounds and other intellectual property controlled by Anacor for the treatment, diagnosis, or prevention of certain bacterial pathogens (the “Anacor License Amendment”). The Anacor License Amendment has no impact on the Anacor License financial terms. None of the development, regulatory, commercial or sales milestones or royalty payments were recognized during the three and nine months ended September 30, 2023 . As a result, the Company did no t record any research and development expense—related party in the condensed statements of operations for the three and nine months ended September 30, 2023. During the three and nine months ended September 30, 2022 , the Company recorded $ 1.0 million in research and development expense - related party to Anacor upon the achievement of a milestone. Brii Biosciences Agreement In November 2019, the Company entered into a license agreement granting Brii Biosciences Limited the exclusive development and commercialization rights of certain compounds in China, Hong Kong, Taiwan, and Macau for the treatment of human diseases. The Company did no t receive an upfront payment but is eligible to receive up to $ 15.0 million in the aggregate for development and regulatory milestones and up to $ 150.0 million in commercial milestones upon achieving sales thresholds. The Company is also entitled to tiered mid-single digits to high-first decile percentage sales-based royalties. The sales royalties are required to be paid on a product-by-product and region-by-region basis, until the latest to occur of 15 years following the date of first commercial sale of a product, the expiration of all regulatory or data exclusivity, or the date upon the expiration of the last to expire claim of a licensed patent covering the composition of matter or approved use of such product in such region. The last to expire valid claim of a licensed patent covering the composition of matter or approved use of such product in the licensed territory is June 2028. Future milestone payments and royalties will be accounted for under ASC 606.

Balance Sheet Components

Balance Sheet Components	9 Months Ended
	Sep. 30, 2023
Balance Sheet Related Disclosures [Abstract]
Balance Sheet Components	Note 6 . Balance Sheet Components Accrued Liabilities Accrued liabilities consist of the following (in thousands): September 30, December 31, 2023 2022 Accrued research and development-related expenses $ 6,744 $ 2,517 Accrued professional services expenses 46 198 Other — 122 Total accrued liabilities $ 6,790 $ 2,837

Commitment and Contingencies

Commitment and Contingencies	9 Months Ended
	Sep. 30, 2023
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Note 7 . Commitments and Contingencies Contingencies From time to time, the Company may become involved in legal proceedings arising in the ordinary course of business. The Company was not subject to any material legal proceedings as of September 30, 2023 and December 31, 2022, and no material legal proceedings are currently pending or threatened. Guarantees and Indemnifications The Company, as permitted under Delaware law and in accordance with its certification of incorporation, as amended, and bylaws, and pursuant to indemnification agreements with certain of its officers and directors, indemnifies its officers and directors for certain events or occurrences, subject to certain limits, which the officer or director is or was serving at the Company’s request in such capacity. The term of the indemnification period lasts as long as an officer or director may be subject to any proceeding arising out of acts or omissions of such officer or director in such capacity. The maximum amount of potential future indemnification is unlimited; however, the Company currently holds director and officer liability insurance. This insurance limits the Company’s exposure and may enable it to recover a portion of any future amounts paid. The Company believes that the fair value of these indemnification obligations is minimal. Accordingly, the Company has not recognized any liabilities relating to these obligations for any period presented. Adjuvant Global Health Agreement In conjunction with Adjuvant Global Health Technology Fund L.P.’s (“Adjuvant”) investment in the Company’s Series A redeemable convertible preferred stock financing in 2019 and 2020, the Company entered into a Global Health Agreement with Adjuvant, pursuant to which the Company agreed to support the creation of innovative and affordable drugs to treat disease, through public health programs and private purchasers in Low and Lower-Middle-Income Countries (as such terms are defined by the World Bank and in the agreement). Adjuvant’s investment supports the development of the Company’s product candidate, epetraborole, for use in melioidosis-endemic and melioidosis-at-risk countries as defined in the agreement. These global access commitments became effective as of the Series A redeemable convertible preferred stock financing closing date and will remain in effect until the latter of either that Adjuvant ceases to be a shareholder of the Company, or ten years following epetraborole approval for the treatment of melioidosis by a regulatory authority. The Global Health Agreement contains various affirmative and negative covenants agreed to by the Company, including its use of reasonably diligent endeavors to develop the agreed-upon products using non-dilutive funding and make accessible to people in need in the target countries so long as the Company does not sell products at a loss. Other covenants include prohibition of use of investment for propaganda, attempt to influence legislation, influence of any public election or voter registration drive or promotion of terrorist activities, as well as compliance with certain environmental, social and governance requirements and anti-corruption requirements. If the Company does not maintain compliance with these non-financial covenants, Adjuvant may be entitled to repayment for any portion of its investment that is not used for the purposes outlined in the Global Health Agreement. In conjunction with Adjuvant’s investment in the Company’s Series B redeemable convertible preferred stock financing in 2021, the Company entered into an Amended and Restated Global Health Agreement (the “Adjuvant Amendment”). The Adjuvant Amendment expands Adjuvant’s investment support to include the development of the Company’s product candidate, epetraborole, for use in tuberculosis-endemic and tuberculosis-at-risk countries as defined in the agreement. In connection with Adjuvant’s investment in the Company’s common stock as part of the IPO, the Company entered into an Amended and Restated Global Health Agreement dated March 24, 2022 (the “Adjuvant IPO Amendment”). As part of the Adjuvant IPO Amendment, Adjuvant purchased 166,666 shares of the Company's common stock in March 2022 for a total additional investment of $ 2.5 million, which is subject to Adjuvant’s right of repayment should the Company not utilize the proceeds from Adjuvant’s investment towards the agreed-upon purpose. As of December 31, 2022, the $ 2.5 million of proceeds from Adjuvant’s IPO investment, as well as the proceeds from Adjuvant’s Series A and B redeemable convertible preferred stock investments, were fully utilized to support the epetraborole development program, which overlaps with the melioidosis and other global health development programs. In addition, the Company has complied with all applicable covenants as of September 30, 2023 .

Equity

Equity	9 Months Ended
	Sep. 30, 2023
Equity [Abstract]
Equity	Note 8 . Equity Common Stock The Company’s certificate of incorporation, as amended, authorizes the Company to issue up to 500,000,000 shares of $ 0.00001 par value common stock. Holders of common stock are entitled to one vote per share on all matters to be voted upon by the stockholders of the Company. Subject to the preferences that may be applicable to any outstanding shares of preferred stock, the holders of common stock are entitled to receive ratably such dividends, if any, as may be declared by the Board of Directors. No dividends have been declared to date. On April 6, 2023, the Company entered into a Sales Agreement with Cowen and Company, LLC as the Company’s Agent, to issue and sell up to an aggregate gross sales of $ 100.0 million in Shares of the Company’s common stock through the ATM Offering. During the nine months ended September 30, 2023 , the Company issued and sold 2,502,000 shares of common stock under the ATM program, resulting in net proceeds of $ 19.1 million, after deducting commissions and other offering costs. On August 15, 2023, the Company entered into an Underwriting Agreement with Cowen and Company, LLC, Leerink Partners LLC and Evercore Group L.L.C. as representatives of several underwriters to issue and sell 7,777,778 shares of common stock at an offering price of $ 9.00 per share through the Underwritten Offering, resulting in net proceeds of $ 65.5 million, after deducting commissions and other offering costs. Shares of common stock reserved for future issuance, on an as-if-converted basis, as of September 30, 2023 and December 31, 2022, consists of the following: September 30, December 31, 2023 2022 Stock options, issued and outstanding 3,821,869 2,796,241 Stock options, authorized for future issuance 1,363,158 1,627,680 ESPP, authorized for future issuance 337,017 187,000 Total 5,522,044 4,610,921 Preferred Stock The Company’s certificate of incorporation, as amended, authorizes the Company to issue up to 10,000,000 shares of $ 0.00001 par value preferred stock. The preferred stock is not convertible. No shares of preferred stock were issued and outstanding at September 30, 2023 and December 31, 2022 .

Equity Incentive Plan and Stock

Equity Incentive Plan and Stock-Based Compensation	9 Months Ended
	Sep. 30, 2023
Share-Based Payment Arrangement [Abstract]
Equity Incentive Plan and Stock-Based Compensation	Note 9 . Equity Incentive Plan and Stock-Based Compensation 2022 Equity Incentive Plan The Company adopted the 2022 Equity Incentive Plan (the “2022 Plan”) effective upon the closing of the IPO, which provides for the granting of incentive stock options (“ISOs”) to the Company's employees, and for the grant of nonstatutory stock options (“NSOs”), stock appreciation rights, restricted stock awards, restricted stock unit awards, performance awards, and other forms of awards to employees, directors, and consultants. As of September 30, 2023 , no stock appreciation rights, restricted stock awards, restricted stock unit awards or performance awards were issued. The Company initially reserved for issuance 1,870,000 new shares of common stock pursuant to the 2022 Plan. The Company’s 2017 Equity Incentive Plan (the “2017 Plan”) was terminated in 2022; however, shares underlying outstanding stock awards granted under the 2017 Plan will continue to be governed by the 2017 Plan. Shares available under the 2017 Plan were added to the available shares in the 2022 Plan. Shares underlying outstanding stock awards granted under the 2017 Plan that expire or are repurchased by, forfeited to, cancelled or withheld by the Company will also be reserved for issuance under the 2022 Plan. The maximum number of shares of the Company’s common stock that may be issued under the 2022 Plan will not exceed 4,423,920 shares of the Company's common stock, which is the sum of (i) 1,870,000 new shares, plus (ii) 2,553,920 shares related to the 2017 Plan. In addition, the number of shares of the Company’s common stock reserved for issuance under the 2022 Plan will automatically increase on January 1 of each year for a period of ten years , beginning on January 1, 2023 and continuing through January 1, 2032, in an amount equal to (1) 4 % of the total number of shares of the Company’s common stock outstanding on December 31 of the immediately preceding year, or (2) a lesser number of shares determined by the Company's board of directors no later than December 31 of the immediately preceding year. The maximum number of shares of the Company's common stock that may be issued on the exercise of stock options under the 2022 Plan is 13,271,760 shares. Since the date of incorporation and through September 30, 2023, the Company issued stock options to its employees, directors and consultants. As of September 30, 2023 , 1,363,158 shares of common stock remained available for future issuance under the 2022 Plan. ISOs granted to newly hired employees under the 2022 Plan generally vest 25 % after the completion of 12 months of service, and the balance vests in equal monthly installments over the next 36 months of service and expire ten years from the grant date, unless subject to provisions regarding 10% stockholders. ISOs granted to existing employees generally vest ratably over a 48 -month period of service and expire ten years from the grant date. NSOs vest in accordance with the terms of the specific agreement under which the options were provided and expire ten years from the date of grant. Stock-Based Compensation Expense The following table summarizes the components of stock-based compensation expense recognized in the Company’s condensed statements of operations and comprehensive loss during the three and nine months ended September 30, 2023 and 2022 (in thousands): Three Months Ended September 30, Nine Months Ended September 30, 2023 2022 2023 2022 Research and development expenses $ 1,045 $ 446 $ 3,113 $ 1,087 General and administrative expenses 1,124 782 3,067 1,832 Total $ 2,169 $ 1,228 $ 6,180 $ 2,919 Stock Option Plan Activity A summary of the stock plan activity is as follows: Total Options Outstanding Weighted-Average Weighted-Average Remaining Contractual Life Aggregate Intrinsic Value Outstanding at December 31, 2022 2,796,241 $ 10.13 8.81 $ 5,793 Granted 1,093,894 $ 12.40 Exercised ( 15,000 ) $ 6.60 Forfeited ( 53,266 ) $ 10.45 Outstanding at September 30, 2023 3,821,869 $ 10.79 8.37 $ 21,409 Exercisable as of September 30, 2023 1,602,693 $ 8.98 7.72 $ 11,851 As of September 30, 2023 , there was unrecognized stock-based compensation expense of $ 18.9 million related to unvested stock options which the Company expects to recognize over a weighted-average period of 2.4 years. Weighted-average grant-date fair value of the options granted during the nine months ended September 30, 2023 was $ 9.35 per share. Liability for Early Exercise of Stock Options The Company's 2017 Plan permitted early exercise of certain stock options prior to vesting to certain directors, officers, and employees. Any shares issued pursuant to unvested options are restricted and subject to repurchase by the Company until the conditions for vesting are met. The amounts paid for shares purchased under an early exercise of stock options and subject to repurchase by the Company are reported as options subject to repurchase, short and long-term on the balance sheet and is reclassified to common stock and additional paid-in capital as such shares vest. Upon termination of employment of an option-holder, the Company has the right to repurchase, at the original purchase price, any unvested options. As of September 30, 2023 , there were 7,295 unvested common shares outstanding that were issued upon the early exercise of stock options prior to the vesting of the underlying shares which are subject to repurchase by the Company at the original issuance price upon termination of the stockholders’ services. The right to repurchase these shares generally lapses with respect to 25 % of the shares underlying the option after one year of service to the Company and 1/48 th of the shares underlying the original grant per month for 36 months thereafter. The shares purchased by the option-holders pursuant to the early exercise of stock options are not deemed, for accounting purposes, to be issued until those shares vest. As of September 30, 2023, the Company recorded an insignificant amount of liabilities associated with the cash received for shares issued subject to repurchase rights, recorded within the options subject to repurchase, short-term, and options subject to repurchase, long-term on the Company's condensed balance sheets. 2022 Employee Stock Purchase Plan The Company’s 2022 Employee Stock Purchase Plan (“ESPP”) has two components: a component that is intended to qualify as an “employee stock purchase plan” under Section 423 of the Code (the 423 Component) and a component that is not intended to qualify (the Non-423 Component). The ESPP allows eligible employees to purchase shares of the Company’s common stock at a discount through payroll deductions of up to 15 % of their eligible compensation. At the end of each offering period, employees are able to purchase shares at 85 % of the lower of the fair market value of the Company’s common stock at the beginning of the offering period or at the end of each applicable purchase period. Subject to adjustment in the case of certain capitalization events, 187,000 shares of the Company’s common stock were available for purchase at the adoption of the ESPP. Pursuant to the ESPP, the annual share increase pursuant to the evergreen provision is determined based on the least of (i) 1 % of the Company’s common stock outstanding as of December 31 of the immediately preceding year, (ii) 561,000 shares, or (iii) such number of shares as determined by the Board. Accordingly, effective January 1, 2023, the number of shares in the ESPP increased by 194,026 shares, representing 1 % of the prior year end’s common stock outstanding . As of September 30, 2023 , 337,017 shares of common stock remained available for issuance under the ESPP. The Company began recording stock-based compensation expense for its ESPP on October 1, 2022. During the three and nine months ended September 30, 2023 , the Company recognized $ 0.1 million and $ 0.2 million in stock-based compensation expense related to the ESPP, respectively.

Net Loss Per Share

Net Loss Per Share	9 Months Ended
	Sep. 30, 2023
Earnings Per Share [Abstract]
Net loss per share	Note 10 . Net Loss Per Share The following table sets forth the computation of the basic and diluted net loss per share (in thousands, except for per share amounts): Three Months Ended September 30, Nine Months Ended September 30, 2023 2022 2023 2022 Numerator: Net loss $ ( 16,707 ) $ ( 11,339 ) $ ( 47,834 ) $ ( 29,114 ) Add accretion to redemption value and cumulative dividends on preferred stock — — — ( 1,820 ) Net loss attributable to common stockholders $ ( 16,707 ) $ ( 11,339 ) $ ( 47,834 ) $ ( 30,934 ) Denominator: Weighted-average common shares outstanding used to calculate net loss per share attributable to common stockholders, basic and diluted 25,645,421 19,347,148 21,532,537 13,987,862 Net loss per share attributable to common stockholders, basic and diluted $ ( 0.65 ) $ ( 0.59 ) $ ( 2.22 ) $ ( 2.21 ) Since the Company was in a loss position for all periods presented, basic net loss per share is the same as diluted net loss per share for all periods as the inclusion of all potential common shares outstanding would have been anti-dilutive. Potentially dilutive securities that were not included in the diluted per share calculations because they would be anti-dilutive were as follows: September 30, 2023 2022 Options issued and outstanding 3,821,869 2,468,491 Early exercised common stock subject to future vesting 7,295 25,462 Total 3,829,164 2,493,953

Related Party Transactions

Related Party Transactions	9 Months Ended
	Sep. 30, 2023
Related Party Transactions [Abstract]
Related Party Transactions	Note 11. Related Party Transactions In the nine months ended September 30, 2023 , the Company had no material related party transactions. In the nine months ended September 30, 2022, the Company paid $ 1.5 million for two development milestones to Anacor. Of this amount, a $ 0.5 million payment was recognized as expense in 2021 and was included as accrued expenses in the accompanying balance sheet at December 31, 2021. In connection with Adjuvant’s investment in the Company’s common stock as part of the IPO, the Company entered into the Adjuvant IPO Amendment. As part of the Adjuvant IPO Amendment, Adjuvant purchased 166,666 shares of the Company's common stock in 2022 for a total additional investment of $ 2.5 million, which is subject to Adjuvant’s right of repayment should the Company not utilize the proceeds from Adjuvant’s investment towards the agreed-upon purpose (see Note 7—Commitments and Contingencies).

Basis of Presentation and Sum_2

Basis of Presentation and Summary of Significant Accounting Policies (Policies)	9 Months Ended
	Sep. 30, 2023
Accounting Policies [Abstract]
Basis of Presentation	Basis of Presentation The Company’s financial statements have been prepared in accordance with United States generally accepted accounting principles (“U.S. GAAP”).
Stock Split	For all periods presented, shares of common stock and then existing redeemable convertible preferred stock and per share amounts have been adjusted on a retroactive basis to reflect our 2.352936 -for-1 forward stock split , which was effected on March 18, 2022. The stock split did not change the par value of the common stock and redeemable convertible preferred stock or the authorized number of shares of common stock and redeemable convertible preferred stock.
Unaudited Interim Condensed Financial Information	Unaudited Interim Condensed Financial Information The accompanying condensed balance sheet as of September 30, 2023, the condensed statements of operations and comprehensive loss and the condensed statements of redeemable convertible preferred stock and stockholders’ equity for the three and nine months ended September 30, 2023 and 2022, and the condensed statements of cash flows for the nine months ended September 30, 2023 and 2022 are unaudited. The unaudited interim condensed financial statements have been prepared on the same basis as the audited annual financial statements and, in the opinion of management, reflect all adjustments, which include only normal recurring adjustments, necessary for the fair statement of the Company’s financial position as of September 30, 2023 and the results of its operations and its cash flows for the nine months ended September 30, 2023 and 2022. The financial data and other information disclosed in these notes related to the nine months ended September 30, 2023 and 2022 are also unaudited. The results for the nine months ended September 30, 2023 are not necessarily indicative of results to be expected for the year ending December 31, 2023, any other interim periods, or any future year or period. The balance sheet as of December 31, 2022 included herein was derived from the audited financial statements as of that date. Certain disclosures have been condensed or omitted from the interim condensed financial statements. Accordingly, these unaudited interim condensed financial statements should be read in conjunction with the Company’s audited financial statements as of and for the year ended December 31, 2022, which are included in the Company’s Annual Report on Form 10-K, as filed with the U.S. Securities and Exchange Commission (“SEC”), dated March 29, 2023.
Risks and Uncertainties	Risks and Uncertainties Liquidity Prior to the Company’s IPO in March 2022, the Company’s operations had historically been financed through the issuance of redeemable convertible preferred stock. Since inception, the Company has incurred significant losses and negative net cash flows from operations. During the nine months ended September 30, 2023 and 2022, the Company incurred a net loss of $ 47.8 million and $ 29.1 million, respectively, and had cash flows used in operating activities of $ 36.2 million and $ 25.8 million, respectively. The Company has an accumulated deficit of $ 137.6 million and $ 89.7 million as of September 30, 2023 and December 31, 2022, respectively, and will require substantial additional capital for research and development activities. The Company anticipates incurring additional losses until such time, if ever, that it can generate significant sales of its product candidate currently in development. As of September 30, 2023, the Company had cash and cash equivalents, short-term investments and long-term investments of $ 150.2 million. Management believes that its cash, cash equivalents and investments as of September 30, 2023 will be sufficient to fund its current operating plan through at least 12 months from the issuance date of these condensed financial statements. Future capital requirements will depend on many factors, including the timing and extent of spending on research and development, including costs for preclinical and nonclinical studies, clinical trials and clinical trial, registration and pre-registration material manufacturing. There can be no assurance that, in the event the Company requires additional financing, such financing will be available at terms acceptable to the Company, if at all. Failure to generate sufficient cash flows from operations, raise additional capital, and reduce discretionary spending should additional capital not become available could have a material adverse effect on the Company’s ability to achieve its intended business objectives. Other Risks and Uncertainties Although the public health effects of the COVID-19 pandemic have subsided and the public-health emergency has ended, we continue to observe lingering impacts in the form of staffing shortages at clinical sites, which may have caused and continue to cause delays in activating sites and screening and enrolling patients. Because of the above and other factors, along with global market and macroeconomic fluctuations and global conflicts, our results of operations may vary substantially from year to year and from quarter to quarter and, as a result, we believe that period to period comparisons of our operating results may not be meaningful and should not be relied upon as being indicative of our future performance. For more information on the risks and uncertainties associated with the evolving effects of macroeconomic headwinds and the COVID-19 pandemic on our business and our clinical development and regulatory efforts, see “Part II Item 1A—Risk Factors.”
Segments	Segments The Company operates and manages its business as one reportable and operating segment. The Company’s chief executive officer, who is the chief operating decision maker, reviews financial information on a company-wide basis for purposes of allocating resources and assessing financial performance.
Use of Estimates	Use of Estimates The preparation of financial statements in conformity with U.S. GAAP requires management to make estimates and judgments that affect the reported amounts of assets and liabilities and disclosures of contingent assets and liabilities as of the date of the financial statements and the reported amounts of expenses during the reporting period. On an ongoing basis, management evaluates its estimates, including those related to research and development accruals, fair value of assets and liabilities and stock-based compensation. Management bases its estimates on historical experience and on various other market-specific and relevant assumptions that management believes to be reasonable under the circumstances. Actual results could differ from those estimates.
Deferred Offering Costs	Deferred Offering Costs The Company capitalizes certain legal, accounting and other third-party fees that are directly related to the Company’s equity financings, including its Underwritten Offering in August 2023, shelf offering and ATM Offering filed in April 2023 and its IPO in 2022, until such financings are consummated. After consummation of the equity financing, these costs are recorded as a reduction of the proceeds received as a result of the financing. The Company capitalized certain legal, accounting and other third-party fees that were directly related to the Company’s Underwritten Offering, ATM Offering and IPO. After the completion of the IPO in March 2022, the total deferred offering costs of $ 3.3 million were offset against the proceeds from the IPO and reclassified to additional paid-in capital in the accompanying condensed balance sheets. After the completion of the ATM Offering in June 2023, the total deferred offering costs of $ 0.9 million were offset against the proceeds from the ATM Offering and reclassified to additional paid-in capital in the accompanying condensed balance sheets. After the completion of the Underwritten Offering in August 2023, the total deferred offering costs of $ 4.5 million were offset against the proceeds from the Underwritten Offering and reclassified to additional paid-in capital in the accompanying condensed balance sheets. At September 30, 2023 and December 31, 2022 , no deferred offering costs were included as non-current assets in the accompanying balance sheets.
Research and Development Expenses	Research and Development Expenses All research and development costs, including work performed by third parties, are expensed as incurred. Research and development costs consist of salaries and other personnel-related expenses, including associated stock-based compensation, consulting fees, and facility costs, as well as fees paid to other entities that conduct certain research and development activities on behalf of the Company. Payments made prior to the receipt of goods or services to be used in research and development are capitalized until the goods are received or services are rendered. As part of the process of preparing its financial statements, the Company estimates its accrued expenses. This process involves reviewing quotations and contracts, identifying services that have been performed on the Company’s behalf and estimating the level of services performed and the associated cost incurred for services for which the Company has not yet been invoiced or otherwise notified of the actual cost. The majority of the Company’s service providers invoice monthly in arrears for services performed or when contractual milestones are met. The Company makes estimates of its accrued expenses at the end of each reporting period based on the facts and circumstances known to the Company at that time. The significant estimates in the Company’s accrued research and development expenses relate to expenses incurred with respect to contract manufacturing and clinical and other research organizations, academic research centers and other vendors in connection with research and development activities for which the Company has not yet been invoiced.
Redeemable Convertible Preferred Stock	Redeemable Convertible Preferred Stock The Company recorded the redeemable convertible preferred stock at fair value on the dates of issuance, net of issuance costs. The carrying value of the redeemable convertible preferred stock was accreted to its redemption value. Immediately prior to the closing of the IPO, all outstanding shares of the Company’s redeemable convertible preferred stock were converted into shares of common stock and the related carrying value was reclassified to common stock and additional paid-in capital. There were no shares of redeemable convertible preferred stock outstanding as of September 30, 2023 .
Stock-Based Compensation	Stock-Based Compensation The Company measures and recognizes compensation expense for equity-classified stock-based awards made to employees, directors and non-employees based on the grant date estimated fair value of each award. Compensation expense for employee and director awards is recognized on a straight-line basis over the requisite service period which is generally the vesting period for the entire award. Expense is adjusted for forfeitures as they occur. Compensation expense for non-employee awards is recognized in the same period and manner as if the Company had paid cash for the goods or services provided. The valuation model used for calculating the fair value of stock options for stock compensation expense is the Black-Scholes option-pricing model (the Black-Scholes model). The Black-Scholes model requires management to make assumptions and judgments about the variables used in the calculation, including the expected term, the expected volatility of common stock, an assumed risk-free interest rate, and expected dividends the Company may pay. Management elected to apply the practical expedient for private companies and used the simplified method to determine the awards’ expected term. Volatility is based on an average of the historical volatilities of the common stock of entities with c haracteristics similar to the Company’s. The risk-free rate is based on the U.S. Treasury yield curve in effect at the time of grant for periods corresponding with the expected life of the option. The Company uses an assumed dividend yield of zero as the Company has never paid dividends and has no current plans to pay any dividends on its common stock. For option awards that contain performance conditions, compensation cost is recognized in the period in which it becomes probable that the performance condition will be satisfied. For option awar ds that vest upon a liquidity event or a change in control, the performance condition is not probable of being achieved until the event occurs. As a result, no compensation expense would be recognized until the performance-based vesting condition is achieved.
Fair Value of Common Stock	Fair Value of Common Stock Prior to the Company's IPO, the absence of an active market for the Company’s common stock required the Company’s board of directors (“Board”) to determine the fair value of its common stock for purposes of granting stock options. The fair value of the Company’s common stock was determined by the Company’s Board with assistance from management and an independent third-party valuation firm. Management’s approach to estimating the fair value of the Company’s common stock was consistent with the methods outlined in the American Institute of Certified Public Accountants’ Practice Aid, Valuation of Privately-Held- Company Equity Securities Issued as Compensation . Determining the best estimated fair value of the Company’s common stock requires significant judgment and management considers several factors, including the Company’s stage of development, equity market conditions affecting comparable public companies, significant milestones and progress in research and development efforts. Since the completion of its IPO, the Company uses its stock price traded on the Nasdaq Global Select Market to determine the fair value of its common stock.
Cash and Cash Equivalents	Cash and Cash Equivalents The Company considers all highly liquid investments with a maturity of three months or less when purchased to be cash equivalents. Cash equivalents, which consist of money market funds, corporate debt securities and corporate commercial paper, are stated at fair value. As of September 30, 2023 and December 31, 2022, the Company had cash and cash equivalents of $ 32.6 million and $ 27.2 million, respectively.
Investments	Investments Investments consist of U.S. Treasury securities, commercial paper, and U.S. Government agency securities. All of the Company’s investments are classified as available-for-sale and are carried at estimated fair values and reported in cash equivalents, short-term investments or long-term investments. Management determines the appropriate classification of the investments at the time they are acquired and evaluates the appropriateness of such classifications at each balance sheet date. Investments with contractual maturities greater than 12 months are considered long-term investments. The cost of investments sold, if any, is based on the specific identification method. Unrealized gains and losses on available-for-sale investments are reported in accumulated other comprehensive gain (loss) as a separate component of stockholders’ equity. For available-for-sale debt securities in an unrealized loss position, the Company first assesses whether it intends to sell, or it is more likely than not that it will be required to sell the security before recovery of its amortized cost basis. If either of the criteria regarding intent or requirement to sell is met, the security’s amortized cost basis is written down to fair value and recognized in other income (expense) in the statements of operations and comprehensive loss. If neither criterion is met, the Company evaluates whether the decline in fair value is related to credit-related factors or other factors. In making this assessment, management considers the extent to which fair value is less than amortized cost, any changes to the rating of the security by a rating agency, and adverse conditions specifically related to the security, among other factors. Credit-related impairment losses, limited by the amount that the fair value is less than the amortized cost basis, are recorded through an allowance for credit losses in other income (expense), net. Any unrealized losses from declines in fair value below the amortized cost basis as a result of non-credit factors are recognized in accumulated other comprehensive income (loss) as a separate component of stockholders’ equity, along with unrealized gains. Realized gains and losses and declines in fair value, if any, on available-for-sale securities are included in other income (expense) in the statements of operations and comprehensive loss. For purposes of identifying and measuring credit-related impairments, the Company’s policy is to exclude applicable accrued interest from both the fair value and amortized cost basis of the related security. The Company has elected to write-off uncollectible accrued interest receivable balances in a timely manner, which is defined by the Company as when interest due becomes 90 days delinquent. The accrued interest write-off will be recorded by reversing interest income. Accrued interest receivable is recorded to prepaid expenses and other current assets. As of September 30, 2023 and December 31, 2022, the Company had investments of $ 117.6 million and $ 72.1 million, respectively.
Cloud Computing Arrangements	Cloud Computing Arrangements The Company incurs costs to implement cloud computing arrangements (“CCA”) that are hosted by third-party vendors. Implementation costs incurred during the application development stage are considered for capitalization until the software is ready for its intended use. Once capitalized, these costs are then amortized on a straight-line basis over the term of the associated hosting arrangement and are recognized as an operating expense within the statements of operations and comprehensive loss. As of September 30, 2023 , the Company has no t capitalized any CCA implementation costs or amortized any such costs.
Concentrations of Credit Risk	Concentrations of Credit Risk Financial instruments that potentially subject the Company to concentrations of credit risk consist of cash, cash equivalents and investments. The Company’s cash is invested through financial institutions in the United States. The Company’s investments consist of debt securities, issued by highly rated corporate entities or the U.S. government. The Company’s exposure to any individual corporate entity is limited by its investment policy. Deposits may at times exceed federally insured limits, but minimal credit risk exists. The Company invests its cash equivalents in highly rated money market funds. The Company has not experienced any credit losses in such accounts and does not believe it is exposed to any significant credit risk on these funds. The Company is exposed to credit risk in the event of a default by the financial institutions holding its cash to the extent recorded on the condensed balance sheets. In March 2023, one of the financial institutions utilized by the Company was closed by the California Department of Financial Protection and Innovation, which appointed the Federal Deposit Insurance Corporation as receiver. Through September 30, 2023 , the Company had no off-balance sheet concentrations of credit risk.
Government Contract	Government Contract In September 2022, the Company received a cost-reimbursement contract award under which the Company is eligible to receive up to $ 17.8 million from the U.S. National Institute of Allergy and Infection Diseases (“NIAID”) to support preclinical, Phase 1 studies and other activities to enable advancement of epetraborole into late-stage development for acute systemic melioidosis and other biothreat pathogens. This project will be funded in whole or in part with Federal funds from the National Institute of Allergy and Infectious Diseases, National Institutes of Health, Department of Health and Human Services, under Contract No. 75N93022C00059. Accounting for this contract does not fall under ASC 606, Revenue from Contracts with Customers, as NIAID will not benefit directly from the advancement of epetraborole. As there is no authoritative guidance under U.S. GAAP on accounting for government assistance to for-profit business entities, the Company applied International Accounting Standards (IAS) 20, Accounting for Government Grants and Disclosure of Government Assistance, by analogy when accounting for the NIAID contract payments to the Company. Under IAS 20, government contract proceeds are recognized when there is reasonable assurance the conditions of the contract will be met and the contract funding will be received. For the NIAID contract, this occurs after the qualifying expenses related to the contract have been incurred, or the Company concludes the conditions of the contract have been substantially met. The income related to the reimbursement of operating expenses is then recorded as a reduction of those expenses (see Note 4—Funding Arrangements).
Grant Agreements	Grant Agreements In September 2022, the Company entered into a subcontract agreement with the University of Georgia Research Foundation (“UGARF”) to conduct preclinical activities. The Company is eligible to receive up to $ 1.4 million from UGARF to support preclinical development of a boron-containing small molecule for Chagas disease. In September 2023, the Company entered into a grant agreement with the Bill and Melinda Gates Foundation (“BMGF”) to fund up to $ 1.8 million to generate new boron-based lead compounds with the potential to be developed into drugs that treat tuberculosis and malaria. The Company recognizes grant proceeds in accordance with ASC 958-605, Revenue Recognition Not-for-Profit Entities, when qualifying costs are incurred and conditions of the grant agreement have been met. When receipt of grant proceeds is reasonably assured, the Company records a reduction to the research and development expenses incurred and a corresponding grant receivable. Cash received from grants in advance of incurring qualifying costs is recorded as a liability and recognized as a reduction to the qualifying research and development expenses incurred (see Note 4—Funding Arrangements).
Comprehensive Loss	Comprehensive Loss Comprehensive loss includes net loss and certain changes in stockholders’ equity that are excluded from net loss. The Company’s other comprehensive loss consists of net changes in unrealized gains and losses on its available-for-sale investments. For the nine months ended September 30, 2023 and 2022, the Company had $ 0.3 million of net unrealized gain and $ 0.5 million of net unrealized loss , respectively, on available-for-sale investments.
Net Loss Per Share	Net Loss Per Share Basic net loss per share attributable to common stockholders is calculated by dividing the net loss attributable to common stockholders by the weighted-average number of shares of common stock outstanding during the period, without consideration for potentially dilutive securities. Diluted net loss per share attributable to common stockholders is computed by dividing the net loss attributable to common stockholders by the weighted-average number of common stock and potentially dilutive securities outstanding for the period. For purposes of the diluted net loss per share calculation, redeemable convertible preferred stock, stock options, common stock subject to repurchase related to unvested early exercise of stock options are considered to be potentially dilutive securities. Basic and diluted net loss attributable to common stockholders per share is presented in conformity with the two-class method required for participating securities as the redeemable convertible preferred stock is considered a participating security because it participates in dividends with common stock, and is accreted to redemption. The Company also considers the shares issued upon the early exercise of stock options subject to repurchase to be participating securities because holders of such shares have non-forfeitable dividend rights in the event a dividend is paid on common stock. The holders of all series of redeemable convertible preferred stock and the holders of early exercised shares subject to repurchase do not have a contractual obligation to share in the Company’s losses. As such, the net loss was attributed entirely to common stockholders. Because the Company has reported a net loss for all periods presented, diluted net loss per share is the same as basic net loss per share for those periods because the impact of potentially dilutive securities would be anti-dilutive.
JOBS Act Accounting Election	JOBS Act Accounting Election The Company is an emerging growth company, as defined in the Jumpstart Our Business Startups Act of 2012 (the “JOBS Act”). Under the JOBS Act, emerging growth companies can delay adopting new or revised accounting standards issued subsequent to the enactment of the JOBS Act until such time as those standards apply to private companies. The Company has elected to use this extended transition period for complying with new or revised accounting standards that have different effective dates for public and private companies until the earlier of the date the Company (i) is no longer an emerging growth company or (ii) affirmatively and irrevocably opts out of the extended transition period provided in the JOBS Act. The Company may take advantage of these provisions for up to five years (which is through March 2027), unless the Company ceases to be an emerging growth company at an earlier date. As a result, these financial statements may not be comparable to companies that comply with new or revised accounting pronouncements as of public company effective dates.
Recently Adopted Accounting Pronouncements	Recently Adopted Accounting Pronouncements In July 2018, the FASB issued ASU No. 2018-11, Leases (Topic 842): Targeted Improvements (“ASU 2018-11”). ASU 2018-11 provided an alternative method in addition to the modified retrospective transition method for ASU No. 2016-02, Leases: Amendments to the FASB Accounting Standards Codification (“ASU 2016-02”), issued in February 2016. Under ASU 2018-11, an entity may elect to initially apply the new lease standard at the adoption date and recognize a cumulative-effect adjustment to the opening balance of retained earnings in the period of adoption. Under ASU 2016-02, a lease is required to recognize assets and liabilities with lease terms of more than twelve months. ASU 2016-02 is effective for nonpublic business entities and public entities eligible to be Smaller Reporting Companies for fiscal years beginning after December 15, 2021. The Company adopted the new standard on January 1, 2022 using the modified retrospective approach. The Company has elected to apply the transition method that allows companies to continue applying the guidance under the lease standard in effect at that time in the comparative periods presented in the condensed financial statements and recognize a cumulative-effect adjustment to the opening balance of accumulated deficit on the date of adoption. The Company has elected to combine lease components (e.g., fixed rent payments) with non-lease components (e.g., common-area maintenance costs) on its facility and clinical research organization (“CRO”) embedded lease asset classes. The Company also elected the “package of practical expedients”, which permits the Company not to reassess under the new standard the Company’s prior conclusions about lease identification, lease classification and initial direct costs. The Company also elected the short-term lease practical expedients allowed under the standard. Lastly, the Company did not elect the practical expedient allowing the use-of-hindsight which would require the Company to reassess the lease term of its leases based on all facts and circumstances through the effective date. Results for reporting period beginning after January 1, 2022 are presented under the new standard, while prior period amounts are not adjusted and continue to be reported under the accounting standards in effect for the prior period. Upon adoption of the new lease standard, on January 1, 2022, the Company capitalized operating lease right-of-use (ROU) assets of $ 0.05 million and $ 0.05 million of operating lease liabilities, within the condensed balance sheets upon adoption. In November 2021, the FASB issued ASU No. 2021-10, Government Assistance (Topic 832) Disclosures by Business Entities about Government Assistance. Current U.S. GAAP has no specific authoritative guidance on the accounting for, or the disclosure of, government assistance received by business entities. The amendments in this update improve financial reporting by requiring disclosures that increase the transparency of transactions with a government accounted for by applying a grant or contribution accounting model by analogy, including the types of transactions, the accounting for those transactions, and the effect of those transactions on an entity’s financial statements. The amendments in this update require the following annual disclosures about transactions with a government that are accounted for by applying a grant or contribution accounting model by analogy, including: (1) information about the nature of the transactions and the related accounting policy used to account for the transactions; (2) the line items on the balance sheet and income statement that are affected by the transactions, and the amounts applicable to each financial statement line item; and (3) the significant terms and conditions of the transactions, including commitments and contingencies. The amendments in this update are effective for all entities within their scope for financial statements issued for annual periods beginning after December 15, 2021. Early application of the amendments is permitted. The Company adopted this update during the quarter ended September 30, 2022 and accounted for the NIAID contract in accordance with this update. In August 2018, the FASB issued ASU 2018-15, “Intangibles—Goodwill and Other—Internal-Use Software (Subtopic 350-40): Customer’s Accounting for Implementation Costs Incurred in a Cloud Computing Arrangement That Is a Service Contract (a consensus of the FASB Emerging Issues Task Force)”. This update is intended to guide entities in evaluating the accounting for fees paid by a customer in a cloud computing arrangement by providing guidance for determining when the arrangement includes a software license. This standard was effective for financial statements issued by public companies for annual and interim periods beginning after December 15, 2019, and effective for financial statements issued by non-public entities for annual periods beginning after December 15, 2020. The Company adopted this standard beginning July 1, 2022 , noting that this standard was applied prospectively. Adoption of this standard did not have a material impact on the Company's condensed financial statements. In June 2016, the FASB issued ASU No. 2016-13, Financial Instruments—Credit Losses (Topic 326) Measurement of Credit Losses on Financial Instruments (“ASU 2016-13”), which requires an entity to utilize a new impairment model known as the current expected credit loss (“CECL”) model to estimate its lifetime “expected credit loss” and record an allowance that, when deducted from the amortized cost basis of the financial assets and certain other instruments, including but not limited to available-for-sale debt securities. Credit losses relating to available-for-sale debt securities will be recorded through an allowance for credit losses rather than as a direct write-down to the security. ASU 2016-13 requires a cumulative effect adjustment to the balance sheet as of the beginning of the first reporting period in which the guidance is effective. In November 2019, the FASB issued ASU 2019-10, Financial Instruments—Credit Losses (Topic 326), Derivatives and Hedging (Topic 815) and Leases (Topic 842): Effective Dates, which defers the effective date of ASU 2016-13 to fiscal years beginning after December 15, 2022 for SEC reporting companies that are smaller reporting companies such as the Company. The Company adopted this standard beginning January 1, 2023 . Adoption of this standard did not have a material impact on the Company's condensed financial statements.
Recent Accounting Pronouncements Not Yet Adopted	Recent Accounting Pronouncements Not Yet Adopted From time to time, new accounting pronouncements are issued by the FASB or other standard setting bodies and adopted by the Company as of the specified effective date. Unless otherwise noted, the Company believes that the impact of recently issued standards that are not yet effective will not have a material impact on its condensed financial statements and disclosures. As an “emerging growth” company, it has been the Company’s intention to take advantage of certain temporary exemptions from various reporting requirements, as well as taking advantage of additional transitional relief.

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	9 Months Ended
	Sep. 30, 2023
Fair Value Disclosures [Abstract]
Summary of Financial Assets Fair Value Measurement on Recurring Basis	The following table presents the Company’s financial assets, which consist of cash equivalents and investments classified as available-for-sale investments, that are measured at fair value on a recurring basis (in thousands): September 30, 2023 Level Amortized Cost Unrealized Gain Unrealized Loss Estimated Fair Value Cash equivalents: Money market funds Level 1 $ 22,040 $ — $ — $ 22,040 Short-term investments: U.S. Treasury securities Level 1 13,569 — ( 6 ) 13,563 U.S. Government agency securities Level 2 23,315 6 ( 22 ) 23,299 Commercial paper Level 2 40,887 — ( 66 ) 40,821 Asset-backed securities Level 2 8,659 — ( 20 ) 8,639 Corporate debt securities Level 2 4,881 — ( 1 ) 4,880 Long-term investments: U.S. Treasury securities Level 1 21,369 — ( 15 ) 21,354 U.S. Government agency securities Level 2 5,000 2 — 5,002 Total $ 139,720 $ 8 $ ( 130 ) $ 139,598 December 31, 2022 Level Amortized Cost Unrealized Gain Unrealized Loss Estimated Fair Value Cash equivalents: Money market funds Level 1 $ 10,152 $ — $ — $ 10,152 Short-term investments: U.S. Treasury securities Level 1 29,381 — ( 213 ) 29,168 Commercial paper Level 2 27,701 2 ( 82 ) 27,621 U.S. Government agency securities Level 2 12,126 4 ( 79 ) 12,051 Long-term investments: — U.S. Treasury securities Level 1 1,224 — ( 1 ) 1,223 U.S. Government agency securities Level 2 2,001 — ( 5 ) 1,996 Total $ 82,585 $ 6 $ ( 380 ) $ 82,211

Balance Sheet Components (Table

Balance Sheet Components (Tables)	9 Months Ended
	Sep. 30, 2023
Balance Sheet Related Disclosures [Abstract]
Balance Sheet Components	Accrued liabilities consist of the following (in thousands): September 30, December 31, 2023 2022 Accrued research and development-related expenses $ 6,744 $ 2,517 Accrued professional services expenses 46 198 Other — 122 Total accrued liabilities $ 6,790 $ 2,837

Equity (Tables)

Equity (Tables)	9 Months Ended
	Sep. 30, 2023
Equity [Abstract]
Schedule of Shares of Common Stock Reserved for Future Issuance	Shares of common stock reserved for future issuance, on an as-if-converted basis, as of September 30, 2023 and December 31, 2022, consists of the following: September 30, December 31, 2023 2022 Stock options, issued and outstanding 3,821,869 2,796,241 Stock options, authorized for future issuance 1,363,158 1,627,680 ESPP, authorized for future issuance 337,017 187,000 Total 5,522,044 4,610,921

Equity Incentive Plan and Sto_2

Equity Incentive Plan and Stock-Based Compensation (Tables)	9 Months Ended
	Sep. 30, 2023
Share-Based Payment Arrangement [Abstract]
Summary of Total Stock-Based Compensation	The following table summarizes the components of stock-based compensation expense recognized in the Company’s condensed statements of operations and comprehensive loss during the three and nine months ended September 30, 2023 and 2022 (in thousands): Three Months Ended September 30, Nine Months Ended September 30, 2023 2022 2023 2022 Research and development expenses $ 1,045 $ 446 $ 3,113 $ 1,087 General and administrative expenses 1,124 782 3,067 1,832 Total $ 2,169 $ 1,228 $ 6,180 $ 2,919
Summary of Stock Plan Activity	A summary of the stock plan activity is as follows: Total Options Outstanding Weighted-Average Weighted-Average Remaining Contractual Life Aggregate Intrinsic Value Outstanding at December 31, 2022 2,796,241 $ 10.13 8.81 $ 5,793 Granted 1,093,894 $ 12.40 Exercised ( 15,000 ) $ 6.60 Forfeited ( 53,266 ) $ 10.45 Outstanding at September 30, 2023 3,821,869 $ 10.79 8.37 $ 21,409 Exercisable as of September 30, 2023 1,602,693 $ 8.98 7.72 $ 11,851

Net Loss Per Share (Tables)

Net Loss Per Share (Tables)	9 Months Ended
	Sep. 30, 2023
Earnings Per Share [Abstract]
Schedule of computation of basic and diluted net loss per share	The following table sets forth the computation of the basic and diluted net loss per share (in thousands, except for per share amounts): Three Months Ended September 30, Nine Months Ended September 30, 2023 2022 2023 2022 Numerator: Net loss $ ( 16,707 ) $ ( 11,339 ) $ ( 47,834 ) $ ( 29,114 ) Add accretion to redemption value and cumulative dividends on preferred stock — — — ( 1,820 ) Net loss attributable to common stockholders $ ( 16,707 ) $ ( 11,339 ) $ ( 47,834 ) $ ( 30,934 ) Denominator: Weighted-average common shares outstanding used to calculate net loss per share attributable to common stockholders, basic and diluted 25,645,421 19,347,148 21,532,537 13,987,862 Net loss per share attributable to common stockholders, basic and diluted $ ( 0.65 ) $ ( 0.59 ) $ ( 2.22 ) $ ( 2.21 )
Schedule of potentially dilutive securities that were not included in the diluted per share	Potentially dilutive securities that were not included in the diluted per share calculations because they would be anti-dilutive were as follows: September 30, 2023 2022 Options issued and outstanding 3,821,869 2,468,491 Early exercised common stock subject to future vesting 7,295 25,462 Total 3,829,164 2,493,953

Organization and Description _2

Organization and Description of Business - Additional Information (Details) - USD ($) $ / shares in Units, $ in Thousands					3 Months Ended				9 Months Ended
	Aug. 15, 2023	Apr. 06, 2023	Apr. 08, 2022	Mar. 24, 2022	Sep. 30, 2023	Jun. 30, 2023	Jun. 30, 2022	Mar. 31, 2022	Sep. 30, 2023	Sep. 30, 2022
Subsidiary, Sale of Stock [Line Items]
Net proceeds from offering										$ 70,366
Net proceeds from issuance of common stock									$ 366
Sales Agreement
Subsidiary, Sale of Stock [Line Items]
Percentage of maximum commissions to be paid to agent of gross proceeds of sale		3%
Common Stock
Subsidiary, Sale of Stock [Line Items]
Aggregate number of shares issued			5,290,000
Net proceeds from offering			$ 70,400
Initial Public Offering | Common Stock
Subsidiary, Sale of Stock [Line Items]
Aggregate number of shares issued				4,600,000				4,600,000
Stock issued, price per share				$ 15
Shares converted				11,409,488
Aggregate offering price for shares sold				$ 69,000
Underwriting discounts and commissions				4,800
Offering Costs				3,300
Net proceeds from offering				$ 60,900
At the Market Offering | Sales Agreement
Subsidiary, Sale of Stock [Line Items]
Aggregate gross sales		$ 100,000
Common stock issued and sold									2,502,000
Net proceeds from issuance of common stock									$ 19,100
At the Market Offering | Common Stock
Subsidiary, Sale of Stock [Line Items]
Aggregate number of shares issued						2,502,000
Underwritten Offering | Underwriting Agreement
Subsidiary, Sale of Stock [Line Items]
Stock issued, price per share	$ 9
Common stock issued and sold	7,777,778
Net proceeds from issuance of common stock	$ 65,500
Underwritten Offering | Common Stock
Subsidiary, Sale of Stock [Line Items]
Aggregate number of shares issued					7,777,778
Underwriters | Common Stock
Subsidiary, Sale of Stock [Line Items]
Aggregate number of shares issued			690,000				690,000
Stock issued, price per share			$ 15
Aggregate offering price for shares sold			$ 10,400
Net proceeds from offering			$ 9,500

Basis of Presentation and Sum_3

Basis of Presentation and Summary of Significant Accounting Policies - Additional Information (Details)

1 Months Ended

3 Months Ended

9 Months Ended

Mar. 17, 2022

Sep. 30, 2023 USD ($) shares

Sep. 30, 2022 USD ($)

Sep. 30, 2023 USD ($) shares

Jun. 30, 2023 USD ($)

Mar. 31, 2023 USD ($)

Sep. 30, 2022 USD ($)

Jun. 30, 2022 USD ($)

Mar. 31, 2022 USD ($)

Sep. 30, 2023 USD ($) Segment shares

Sep. 30, 2022 USD ($)

Aug. 15, 2023 USD ($)

Apr. 06, 2023 USD ($)

Dec. 31, 2022 USD ($)

Jul. 01, 2022

Mar. 24, 2022 USD ($)

Jan. 01, 2022 USD ($)

Accounting Policies [Line Items]

Net loss

$ 16,707,000

$ 15,804,000

$ 15,323,000

$ 11,339,000

$ 10,120,000

$ 7,655,000

$ 47,834,000

$ 29,114,000

Cash flows used in operating activities

36,220,000

25,824,000

Accumulated deficit

$ 137,557,000

137,557,000

137,557,000

$ 89,723,000

Cash, cash equivalents, short-term investments and long-term investments

150,200,000

150,200,000

$ 150,200,000

Number of operating segments | Segment

1

Number of reportable Segments | Segment

1

Stockholders' equity forward stock split, conversion ratio

2.352936

Stockholders' equity forward stock split

shares of common stock and then existing redeemable convertible preferred stock and per share amounts have been adjusted on a retroactive basis to reflect our 2.352936-for-1 forward stock split

Deferred offering costs

$ 0

$ 0

$ 0

$ 4,500,000

$ 900,000

0

$ 3,300,000

Redeemable convertible preferred stock outstanding | shares

0

0

0

Assumed dividend yield

$ 0

Cash and cash equivalents

$ 32,616,000

$ 32,616,000

32,616,000

27,219,000

Investments

117,600,000

$ 117,600,000

117,600,000

72,100,000

Capitalized implementation or amortized cost

0

Maximum amount eligible to receive under cost-reimbursement contract award

$ 17,800,000

Net unrealized gain (loss) on available-for-sale investments

$ 300,000

(500,000)

Operating lease right-of-use assets

$ 50,000

Operating lease liabilities

$ 50,000

UGARF

Accounting Policies [Line Items]

Grant award amount

$ 1,400,000

BMGF

Accounting Policies [Line Items]

Grant award amount

$ 1,800,000

ASU 2018-11

Accounting Policies [Line Items]

Change in Accounting Principle, Accounting Standards Update, Adoption Date

Jan. 01, 2022

Jan. 01, 2022

Jan. 01, 2022

Change in Accounting Principle, Accounting Standards Update, Adopted [true false]

true

true

true

ASU 2021-10

Accounting Policies [Line Items]

Change in Accounting Principle, Accounting Standards Update, Adoption Date

Sep. 30, 2022

Change in Accounting Principle, Accounting Standards Update, Adopted [true false]

true

ASU 2018-15

Accounting Policies [Line Items]

Change in Accounting Principle, Accounting Standards Update, Adoption Date

Jul. 01, 2022

Change in Accounting Principle, Accounting Standards Update, Adopted [true false]

true

Change in Accounting Principle, Accounting Standards Update, Immaterial Effect [true false]

true

ASU 2016-13

Accounting Policies [Line Items]

Change in Accounting Principle, Accounting Standards Update, Adoption Date

Jan. 01, 2023

Jan. 01, 2023

Jan. 01, 2023

Change in Accounting Principle, Accounting Standards Update, Adopted [true false]

true

true

true

Change in Accounting Principle, Accounting Standards Update, Immaterial Effect [true false]

true

true

true

Initial Public Offering

Accounting Policies [Line Items]

Net loss

$ 47,800,000

29,100,000

Cash flows used in operating activities

36,200,000

$ 25,800,000

Accumulated deficit

$ 137,600,000

$ 137,600,000

$ 137,600,000

$ 89,700,000

Fair Value Measurements - Summa

Fair Value Measurements - Summary of Financial Assets Fair Value Measurement on Recurring Basis (Details) - Fair Value Measurements Recurring - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Amortized Cost	$ 139,720	$ 82,585
Unrealized Gain	8	6
Unrealized Loss	(130)	(380)
Estimated Fair Value	139,598	82,211
Cash and cash Equivalents | Level 1 | Money Market Funds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Amortized Cost	22,040	10,152
Estimated Fair Value	22,040	10,152
Short-term investments | Level 1 | U.S. Treasury Securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Amortized Cost	13,569	29,381
Unrealized Loss	(6)	(213)
Estimated Fair Value	13,563	29,168
Short-term investments | Level 2 | U.S. Government Agency Securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Amortized Cost	23,315	12,126
Unrealized Gain	6	4
Unrealized Loss	(22)	(79)
Estimated Fair Value	23,299	12,051
Short-term investments | Level 2 | Commercial Paper
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Amortized Cost	40,887	27,701
Unrealized Gain		2
Unrealized Loss	(66)	(82)
Estimated Fair Value	40,821	27,621
Short-term investments | Level 2 | Asset-backed Securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Amortized Cost	8,659
Unrealized Loss	(20)
Estimated Fair Value	8,639
Short-term investments | Level 2 | Corporate Debt Securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Amortized Cost	4,881
Unrealized Loss	(1)
Estimated Fair Value	4,880
Long-term investments | Level 1 | U.S. Treasury Securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Amortized Cost	21,369	1,224
Unrealized Loss	(15)	(1)
Estimated Fair Value	21,354	1,223
Long-term investments | Level 2 | U.S. Government Agency Securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Amortized Cost	5,000	2,001
Unrealized Gain	2
Unrealized Loss		(5)
Estimated Fair Value	$ 5,002	$ 1,996

Fair Value Measurements - Addit

Fair Value Measurements - Additional Information (Details)	9 Months Ended
	Sep. 30, 2023 USD ($) Security	Sep. 30, 2022 USD ($)	Dec. 31, 2022 USD ($)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Transfer of level 1 to level 2	$ 0
Transfer of level 2 to level 1	$ 0
Debt securities unrealized loss position, more than12 months number of positions | Security	0
Available-for-sale, sale of investments	$ 0	$ 0
Allowance for credit losses	0		$ 0
Impairment losses related to investments	0	$ 0
Prepaid Expenses and Other Current Assets
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Accrued interest receivable	$ 500,000		$ 200,000

Funding Arrangements - Addition

Funding Arrangements - Additional Information (Details)	1 Months Ended			3 Months Ended	9 Months Ended
	Sep. 30, 2023 USD ($)	Jul. 31, 2023 USD ($) Option	Sep. 30, 2022 USD ($)	Sep. 30, 2023 USD ($)	Sep. 30, 2023 USD ($)
Government Assistance [Line Items]
Maximum amount eligible to receive under cost-reimbursement contract award			$ 17,800,000
Other liabilities current	$ 973,000			$ 973,000	$ 973,000
NIAID Contract
Government Assistance [Line Items]
Maximum amount eligible to receive under cost-reimbursement contract award			$ 17,800,000
Government contract income recognized				0	0
Number of option exercised for government contract | Option		1
Number of available options under government contract | Option		7
Government contract fund increased amount		$ 700,000
Funding of option extends estimated completion of contract term		13 months
Proceeds from government contract		$ 5,000,000
Contract term		18 months
NIAID Contract | Maximum
Government Assistance [Line Items]
Number of option period for funding from government contract			48 months
UGARF Grant
Government Assistance [Line Items]
Grant award amount			$ 1,400,000
Grant income recognized				400,000	700,000
Grant receivable	400,000			400,000	400,000
BMFG Grant
Government Assistance [Line Items]
Grant award amount	1,800,000
Grant income recognized				24,000	24,000
Grant funding in advance amount	1,000,000
Other liabilities current	$ 1,000,000			$ 1,000,000	$ 1,000,000

Collaboration and License Agr_2

Collaboration and License Agreements - Additional Information (Details) - USD ($)	1 Months Ended	3 Months Ended		9 Months Ended
	Nov. 30, 2019	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Collaboration And License Agreements [Line Items]
Research and development		$ 14,429,000	$ 7,428,000	$ 39,952,000	$ 19,759,000
Anacor Licensing Agreement
Collaboration And License Agreements [Line Items]
Number of days convenience upon written notice until first regulatory approval.	90 days
Number of days convenience upon written notice thereafter	1 year
Payment of non-refundable upfront payment	$ 2,000,000
Research and development		$ 0		$ 0
Research and development expense related party			$ 1,000,000		$ 1,000,000
Aggregate maximum payments upon achievement of development milestones	2,000,000
Aggregate maximum payments upon achievement of commercial and sales threshold milestones	$ 125,000,000
Royalty percentage	50%
Number of years, sales royalty required to be paid	15 years
Brii Biosciences Agreement
Collaboration And License Agreements [Line Items]
Aggregate maximum payments upon achievement of commercial and sales threshold milestones	$ 150,000,000
Number of years, sales royalty required to be paid	15 years
Upfront payment received	$ 0
Brii Biosciences Agreement | Maximum
Collaboration And License Agreements [Line Items]
Aggregate development and regulatory milestones eligible to receive	$ 15,000,000

Balance Sheet Components - Summ

Balance Sheet Components - Summary of Accrued Liabilities (Details) - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022
Accrued Liabilities, Current [Abstract]
Accrued research and development-related expenses	$ 6,744	$ 2,517
Accrued professional services expenses	46	198
Other		122
Total accrued liabilities	$ 6,790	$ 2,837

Commitments and Contingencies -

Commitments and Contingencies - Additional Information (Details) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2023	Dec. 31, 2022	Mar. 28, 2022
Commitments And Contingencies [Line Items]
Common stock, shares issued	29,741,445	19,402,658
Adjuvant Global Health Agreement | Series A Redeemable Convertible Preferred Stock
Commitments And Contingencies [Line Items]
Long term purchase commitment period	10 years
Initial Public Offering | Adjuvant Global Health Agreement
Commitments And Contingencies [Line Items]
Common stock, shares issued			166,666
Total additional investment			$ 2.5
Proceeds From Investment		$ 2.5

Equity - Additional Information

Equity - Additional Information (Details) - USD ($) $ / shares in Units, $ in Thousands			9 Months Ended
	Aug. 15, 2023	Apr. 06, 2023	Sep. 30, 2023	Dec. 31, 2022
Class of Stock [Line Items]
Common stock, shares authorized			500,000,000	500,000,000
Common stock, par value			$ 0.00001	$ 0.00001
Common Stock, Voting Rights			one
Net proceeds from issuance of common stock			$ 366
Preferred stock, shares authorized			10,000,000	10,000,000
Preferred stock, par value			$ 0.00001	$ 0.00001
Preferred stock, shares issued			0	0
Preferred stock, shares outstanding			0	0
Sales Agreement
Class of Stock [Line Items]
Percentage of maximum commissions to be paid to agent of gross proceeds of sale		3%
At the Market Offering | Sales Agreement
Class of Stock [Line Items]
Aggregate gross sales		$ 100,000
Common stock, shares sold			2,502,000
Net proceeds from issuance of common stock			$ 19,100
Underwritten Offering | Underwriting Agreement
Class of Stock [Line Items]
Common stock, shares sold	7,777,778
Stock issued, price per share	$ 9
Net proceeds from issuance of common stock	$ 65,500

Equity - Shares of Common Stock

Equity - Shares of Common Stock Reserved for Future Issuance (Details) - shares	Sep. 30, 2023	Dec. 31, 2022
Class of Stock [Line Items]
Shares of common stock reserved for future issuance (in shares)	5,522,044	4,610,921
Stock Options Issued And Outstanding
Class of Stock [Line Items]
Shares of common stock reserved for future issuance (in shares)	3,821,869	2,796,241
Stock Options Authorized For Future Issuance
Class of Stock [Line Items]
Shares of common stock reserved for future issuance (in shares)	1,363,158	1,627,680
ESPP, Authorized for Future Issuance
Class of Stock [Line Items]
Shares of common stock reserved for future issuance (in shares)	337,017	187,000

Equity Incentive Plan and Sto_3

Equity Incentive Plan and Stock-Based Compensation - Additional Information (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022	Dec. 31, 2022	Jan. 01, 2023	Oct. 01, 2022
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Common stock reserved for future issuance (in shares)	5,522,044		5,522,044		4,610,921
Weighted average grant-date fair value, options granted			$ 9.35
Unrecognized share-based compensation expense related to unvested share options	$ 18,900		$ 18,900
Unrecognized share-based compensation expense expects to recognize over a weighted-average period			2 years 4 months 24 days
Unvested common shares outstanding were issued upon early exercise of stock options	7,295		7,295
Rights to repurchase shares, description			The right to repurchase these shares generally lapses with respect to 25% of the shares underlying the option after one year of service to the Company and 1/48th of the shares underlying the original grant per month for 36 months thereafter.
Share-based payment arrangement expense	$ 2,169	$ 1,228	$ 6,180	$ 2,919
After Completion of 12 months of Service
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Vesting percentage			25%
Rights to repurchase shares, service period			1 year
Over 36 months of Service
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Vesting percentage			0.02%
Vesting period			36 months
Stock Appreciation Rights, Restricted Stock Award, Restricted Stock Unit or Performance Awards
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Number of shares issued	0		0
2017 Equity Incentive Plan
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Common stock reserved for future issuance (in shares)	2,553,920		2,553,920
2022 Equity Incentive Plan
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Common stock reserved for future issuance (in shares)	1,870,000		1,870,000
Maximum number of shares of common stock that may be issued	4,423,920		4,423,920
Shares of common stock remained available for future issuance	1,363,158		1,363,158
Percentage of annual increase in shares reserved for future issuance on common stock outstanding.			4%
Award contractual life (in years)			10 years
2022 Equity Incentive Plan | Incentive Stock Option | Existing Employees
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Vesting period			48 months
2022 Equity Incentive Plan | Incentive Stock Option | Newly Hired Employees
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Vesting period			36 months
2022 Equity Incentive Plan | Incentive Stock Option | After Completion of 12 months of Service | Newly Hired Employees
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Vesting percentage			25%
2022 Equity Incentive Plan | Incentive Stock Option | Over 36 months of Service | Newly Hired Employees
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Award contractual life (in years)			10 years
2022 Equity Incentive Plan | Incentive Stock Option | Over 48 months of Service | Existing Employees
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Award contractual life (in years)			10 years
2022 Equity Incentive Plan | Incentive Stock Option | Maximum
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Maximum number of shares of common stock that may be issued	13,271,760		13,271,760
2022 Equity Incentive Plan | Non-Statutory Stock Options
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Award contractual life (in years)			10 years
2022 Employee Stock Purchase Plan
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Common stock reserved for future issuance (in shares)							187,000
Shares of common stock remained available for future issuance	337,017		337,017
Maximum percentage in payroll deductions to purchase shares of common stock	15%		15%
Employees purchase price of common stock as percentage of lower of fair market value			85%
Percentage of common stock outstanding			1%		1%
Share-based payment arrangement expense	$ 100		$ 200
2022 Employee Stock Purchase Plan | Minimum
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Increase in number of annual shares	561,000		561,000			194,026

Equity Incentive Plan and Sto_4

Equity Incentive Plan and Stock-Based Compensation - Summary of Total Stock-Based Compensation (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Share-Based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Total stock-based compensation	$ 2,169	$ 1,228	$ 6,180	$ 2,919
Research and Development Expense
Share-Based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Total stock-based compensation	1,045	446	3,113	1,087
General and Administrative Expense
Share-Based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Total stock-based compensation	$ 1,124	$ 782	$ 3,067	$ 1,832

Equity Incentive Plan and Sto_5

Equity Incentive Plan and Stock-Based Compensation - Summary of Stock Plan Activity (Details) $ / shares in Units, $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2023 USD ($) $ / shares shares	Dec. 31, 2022 USD ($) $ / shares shares
Share-Based Payment Arrangement [Abstract]
Total Options outstanding, Beginning balance | shares	2,796,241
Total Options outstanding, Granted | shares	1,093,894
Total Options Outstanding, Exercised | shares	(15,000)
Total Options Outstanding, Forfeited | shares	(53,266)
Total Options outstanding, Ending balance | shares	3,821,869	2,796,241
Total Options Outstanding, Exercisable | shares	1,602,693
Weighted average exercise price, Beginning balance | $ / shares	$ 10.13
Weighted average exercise price, Granted | $ / shares	12.4
Weighted average exercise price, Exercised | $ / shares	6.6
Weighted average exercise price, Forfeited | $ / shares	10.45
Weighted average exercise price, Ending balance | $ / shares	10.79	$ 10.13
Weighted Average Exercise Price per Share, Exercisable | $ / shares	$ 8.98
Weighted Average Remaining Contractual Life, Outstanding	8 years 4 months 13 days	8 years 9 months 21 days
Weighted Average Remaining Contractual Life, Exercisable	7 years 8 months 19 days
Aggregate Intrinsic Value, Outstanding | $	$ 21,409	$ 5,793
Aggregate Intrinsic Value, Exercisable | $	$ 11,851

Net Loss Per Share - Summary of

Net Loss Per Share - Summary of Computation of Basic and Diluted Net Loss Per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended						9 Months Ended
	Sep. 30, 2023	Jun. 30, 2023	Mar. 31, 2023	Sep. 30, 2022	Jun. 30, 2022	Mar. 31, 2022	Sep. 30, 2023	Sep. 30, 2022
Numerator:
Net loss	$ (16,707)	$ (15,804)	$ (15,323)	$ (11,339)	$ (10,120)	$ (7,655)	$ (47,834)	$ (29,114)
Accretion to redemption value and cumulative dividends on preferred stock								(1,820)
Net loss attributable to common stockholders	$ (16,707)			$ (11,339)			$ (47,834)	$ (30,934)
Denominator:
Weighted-average common shares outstanding used to calculate net loss per share attributable to common stockholders, basic	25,645,421			19,347,148			21,532,537	13,987,862
Weighted-average common shares outstanding used to calculate net loss per share attributable to common stockholders, diluted	25,645,421			19,347,148			21,532,537	13,987,862
Net loss per share attributable to common stockholders, basic	$ (0.65)			$ (0.59)			$ (2.22)	$ (2.21)
Net loss per share attributable to common stockholders, diluted	$ (0.65)			$ (0.59)			$ (2.22)	$ (2.21)

Net Loss Per Share - Schedule o

Net Loss Per Share - Schedule of Potentially Dilutive Securities Not Included in Diluted Per Share Calculation (Details) - shares	9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Anti-dilutive securities excluded from computation of diluted per share	3,829,164	2,493,953
Option Issued and Outstanding
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Anti-dilutive securities excluded from computation of diluted per share	3,821,869	2,468,491
Early Exercised Common Stock Subject to Future Vesting
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Anti-dilutive securities excluded from computation of diluted per share	7,295	25,462

Related Party Transactions - Ad

Related Party Transactions - Additional Information (Details) - USD ($)	9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Dec. 31, 2022	Mar. 28, 2022	Dec. 31, 2021
Related Party Transaction [Line Items]
Research and development related expense related party	$ 0	$ 1,500,000
Accrued research and development-related expenses- related party					$ 500,000
Common stock, shares issued	29,741,445		19,402,658
Adjuvant Global Health Agreement | Initial Public Offering
Related Party Transaction [Line Items]
Common stock, shares issued				166,666
Total additional investment				$ 2,500,000