Oncternal Therapeutics (ONCT) 10-K 7 Mar 24 2023 FY Annual report Financial data

Document and Entity Information

Document and Entity Information - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Mar. 01, 2024	Jun. 30, 2023
Cover [Abstract]
Entity Registrant Name	Oncternal Therapeutics, Inc.
Entity Central Index Key	0001260990
Document Type	10-K
Document Period End Date	Dec. 31, 2023
Amendment Flag	false
Document Fiscal Year Focus	2023
Document Fiscal Period Focus	FY
Trading Symbol	ONCT
Current Fiscal Year End Date	--12-31
Entity Filer Category	Non-accelerated Filer
Entity Well-known Seasoned Issuer	No
Entity Voluntary Filers	No
Entity Small Business	true
Entity Emerging Growth Company	false
Entity Current Reporting Status	Yes
Document Financial Statement Error Correction [Flag]	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		2,959,645
Entity Public Float			$ 18.8
Entity File Number	000-50549
Entity Tax Identification Number	62-1715807
Entity Address, Address Line One	12230 El Camino Real
Entity Address, Address Line Two	Suite 230
Entity Address, City or Town	San Diego
Entity Address, State or Province	CA
Entity Address, Postal Zip Code	92130
City Area Code	858
Local Phone Number	434-1113
Entity Interactive Data Current	Yes
Title of 12(b) Security	Common Stock, par value $0.001 per share
Security Exchange Name	NASDAQ
Entity Incorporation, State or Country Code	DE
ICFR Auditor Attestation Flag	false
Document Annual Report	true
Document Transition Report	false
Documents Incorporated by Reference	Portions of the Registrant’s proxy statement to be filed with the Securities and Exchange Commission pursuant to Regulation 14A in connection with the Registrant’s 2024 Annual Meeting of Stockholders, which will be filed subsequent to the date hereof, are incorporated by reference into Part III of this Form 10-K. Such proxy statement will be filed with the Securities and Exchange Commission not later than 120 days following the end of the Registrant’s fiscal year ended December 31, 2023.
Auditor Name	BDO USA, P.C.
Auditor Location	San Diego, California
Auditor Firm ID	243

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Current assets:
Cash and cash equivalents	$ 6,697	$ 37,142
Short-term investments	27,558	26,582
Prepaid and other	1,804	3,566
Total current assets	36,059	67,290
Right-of-use asset	258	87
Other assets	412	1,274
Total assets	36,729	68,651
Current liabilities:
Accounts payable	1,148	2,917
Accrued liabilities	3,877	4,678
Lease, current	173	87
Total current liabilities	5,198	7,682
Deferred compensation	1,334	0
Lease, net of current	145	0
Total liabilities	6,677	7,682
Commitments and contingencies (Note 4)
Stockholders’ equity:
Preferred stock, $0.001 par value, authorized shares 5,000 at December 31, 2023 and 2022; issued and outstanding shares none	0	0
Common stock, $0.001 par value; authorized shares - 120,000 at December 31, 2023 and 60,000 at 2022; issued and outstanding shares - 2,948 and 2,829 at December 31, 2023 and 2022, respectively	3	3
Additional paid-in capital	227,825	219,257
Accumulated other comprehensive income	3	9
Accumulated deficit	(197,779)	(158,300)
Total stockholders’ equity	30,052	60,969
Total liabilities and stockholders’ equity	$ 36,729	$ 68,651

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - $ / shares	Dec. 31, 2023	Dec. 31, 2022
Statement of Financial Position [Abstract]
Preferred stock, par value	$ 0.001	$ 0.001
Preferred stock, shares authorized	5,000,000	5,000,000
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Common stock, par value	$ 0.001	$ 0.001
Common stock, shares authorized	120,000,000	120,000,000
Common stock, shares issued	2,948,000	2,874,000
Common stock, shares outstanding	2,948,000	2,874,000

Consolidated Statements of Oper

Consolidated Statements of Operations and Comprehensive Loss - USD ($) shares in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Income Statement [Abstract]
Grant revenue	$ 785,000	$ 1,490,000
Operating expenses:
Research and development	29,753,000	32,980,000
General and administrative	12,746,000	13,457,000
Total operating expenses	42,499,000	46,437,000
Loss from operations	(41,714,000)	(44,947,000)
Interest income	2,235,000	777,000
Net loss	(39,479,000)	(44,170,000)
Comprehensive income
Unrealized gain (loss) on available-for-sale securities, net	(6,000)	9,000
Comprehensive loss	$ (39,485,000)	$ (44,161,000)
Net loss per share, basic	$ (13.43)	$ (16.8)
Net loss per share, diluted	$ (13.43)	$ (16.8)
Weighted-average shares outstanding, basic	2,940	2,630
Weighted-average shares outstanding, diluted	2,940	2,630

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Cash flows from operating activities
Net loss	$ (39,479)	$ (44,170)
Adjustments to reconcile net loss to net cash used in operating activities:
Stock-based compensation	7,500	7,431
Accretion of discounts on short-term investments	(1,633)	(75)
Noncash lease expense	174	179
Changes in operating assets and liabilities:
Prepaid and other assets	2,624	(2,095)
Accounts payable	(1,769)	958
Accrued liabilities	(801)	1,247
Deferred compensation	1,334	0
Change in lease liability	(114)	(179)
Net cash used in operating activities	(32,164)	(36,704)
Cash flows from investing activities
Purchases of available-for-sale securities	(64,349)	(26,498)
Maturities of available-for-sale securities	65,000	0
Net cash provided by investing activities	651	(26,498)
Cash flows from financing activities
Proceeds from the issuance of common stock, net	1,224	9,582
Repurchases of common stock for tax withholding obligations	(156)	(3)
Net cash provided by financing activities	1,068	9,579
Net decrease in cash and cash equivalents	(30,445)	(53,623)
Cash and cash equivalents at beginning of period	37,142	90,765
Cash and cash equivalents at end of period	6,697	37,142
Supplemental disclosure of non-cash investing and financing activities:
Right-of-use assets obtained in exchange for operating lease liabilities	$ 345	$ 191

Consolidated Statements of Conv

Consolidated Statements of Convertible Preferred Stock and Stockholders' Equity - USD ($) $ in Thousands	Total	Common Stock	Additional Paid-in Capital	Accumulated Other Comprehensive Income	Accumulated Deficit
Balance at Dec. 31, 2021	$ 88,120	$ 2	$ 202,248		$ (114,130)
Balance (in shares) at Dec. 31, 2021		2,471,000
Issuance of common stock, net of issuance cost of $375	9,582	$ 1	9,581
Issuance of common stock, net of issuance cost (in shares)		403,000
Shares repurchased for settlement of minimum statutory tax withholdings	(3)		(3)
Stock-based compensation	7,431		7,431
Unrealized gain (loss) on available-for-sale securities	9			$ 9
Net Income (Loss)	(44,170)				(44,170)
Balance at Dec. 31, 2022	$ 60,969	$ 3	219,257	9	(158,300)
Balance (in shares) at Dec. 31, 2022	2,874,000	2,874,000
Issuance of common stock, net of issuance cost of $375	$ 1,224		1,224
Issuance of common stock, net of issuance cost (in shares)		55,000
Shares repurchased for settlement of minimum statutory tax withholdings	(156)		(156)
Issuance of common stock upon vesting of restricted stock units (in Shares)		30,000
Shares repurchased for settlement of minimum statutory tax withholdings (in shares)		(11,000)
Stock-based compensation	7,500		7,500
Unrealized gain (loss) on available-for-sale securities	(6)			(6)
Net Income (Loss)	(39,479)				(39,479)
Balance at Dec. 31, 2023	$ 30,052	$ 3	$ 227,825	$ 3	$ (197,779)
Balance (in shares) at Dec. 31, 2023	2,948,000	2,948,000

Condensed Consolidated Statemen

Condensed Consolidated Statements of Convertible Preferred Stock and Stockholders' Equity (Parenthetical) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Statement of Stockholders' Equity [Abstract]
Common stock, issuance cost	$ 38	$ 375

Pay vs Performance Disclosure

Pay vs Performance Disclosure - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Pay vs Performance Disclosure
Net Income (Loss)	$ (39,479)	$ (44,170)

Insider Trading Arrangements

Insider Trading Arrangements	3 Months Ended
	Dec. 31, 2023
Trading Arrangements, by Individual
Rule 10b5-1 Arrangement Adopted	false
Non-Rule 10b5-1 Arrangement Adopted	false
Rule 10b5-1 Arrangement Terminated	false
Non-Rule 10b5-1 Arrangement Terminated	false
Rule 10B5-1 Arr Modified	false
Non Rule10b5-1 Arr Modified	false

Description of Business, Basis

Description of Business, Basis of Presentation and Summary of Significant Accounting Policies	12 Months Ended
	Dec. 31, 2023
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Description of Business, Basis of Presentation and Summary of Significant Accounting Policies	1. Description of Business, Basis of Presentation and Summary of Significant Accounting Policies Description of Business Oncternal Therapeutics, Inc. (the “Company,” “Oncternal,” or the “combined company”), formerly known as GTx, Inc., was incorporated in Tennessee in September 1997 and reincorporated in Delaware in 2003 and is based in San Diego, California. The Company is a clinical-stage biopharmaceutical company focused on the development of novel oncology therapies for the treatment of cancers with critical unmet medical need. The Company’s clinical pipeline includes ONCT-534, a dual-action androgen receptor inhibitor product candidate for the treatment of castration-resistant prostate and other androgen receptor-driven cancers and ONCT-808, a CAR T (chimeric antigen receptor T-cells) product candidate that targets ROR1, and zilovertamab, a humanized monoclonal antibody that binds to ROR1. Oncternal’s program activities previously included ONCT-216, an investigational small molecule designed to inhibit the E26 Transformation Specific (“ETS”) family of oncoproteins. Principles of Consolidation The consolidated financial statements include the accounts of the Company and its wholly-owned subsidiaries, Oncternal Oncology, Inc. and Oncternal, Inc. All intercompany accounts and transactions have been eliminated in the preparation of the consolidated financial statements. Going Concern The consolidated financial statements have been prepared assuming the Company will continue as a going concern, which contemplates the realization of assets and the satisfaction of liabilities in the normal course of business. From inception, the Company has devoted substantially all of its efforts to drug discovery and development and conducting preclinical studies and clinical trials. The Company has a limited operating history and the sales and income potential of the Company’s business and market are unproven. Successful transition to attaining profitable operations is dependent upon achieving a level of revenues adequate to support the Company’s cost structure. As of December 31, 2023, the Company had $ 34.3 million in cash, cash equivalents, and short-term investments, no debt and an accumulated deficit of $ 197.8 million. From its inception, the Company has incurred recurring operating losses and negative cash flows from operations. The Company has concluded that the balance of cash, cash equivalents and short-term investments will not be sufficient to fund its planned expenditures and meet its obligations for the twelve months following the financial statement issuance date without raising additional funding or making changes to its operating plans or programs to reduce expenses. As a result, there is substantial doubt about the Company’s ability to continue as a going concern for twelve months following the issuance date of these consolidated financial statements. The consolidated financial statements have been prepared assuming the Company will continue as a going concern and do not include any adjustments that might result from the outcome of this uncertainty. The Company expects to continue to incur net losses for the foreseeable future and believes it will need to raise substantial additional capital to accomplish its business plan over the next several years. The Company plans to continue to fund its losses from operations and capital funding needs through a combination of public or private equity or debt offerings or other sources, including potential collaborations, strategic alliances and other similar licensing arrangements in both the short term and long term. If the Company is unable to secure adequate additional funding, the Company may be forced to make reductions in spending, including potentially delaying, scaling back or eliminating certain of its pipeline development programs, extend payment terms with suppliers, or liquidate assets where possible. Any of these actions could materially harm the Company’s business, results of operations and future prospects. As of December 31, 2023, the Company had capacity to issue up to an additional $ 38.8 million of shares of common stock under its at-the-market (“ATM”) equity offering program. Through December 31, 2023, the Company has sold 457,342 shares of common stock for net proceeds of $ 10.8 million under the ATM program. There can be no assurance that the Company will be able to sell any additional shares of its common stock under the ATM program and no assurance regarding the price at which it will be able to sell any such shares, and any sales of shares of its common stock under the ATM program may be at prices that result in additional dilution to existing stockholders of the Company. The Company's ability to obtain additional financing (including through collaborating and licensing arrangements) will depend on a number of factors, including, among others, its ability to generate positive data from its clinical trials and preclinical studies, the condition of the capital markets and the other risks, many of which are dependent on factors outside of its control. There can be no assurance as to the availability or terms upon which such financing and capital might be available in the future. Nasdaq Listing and Reverse Stock Split On April 4, 2023, the Company received a written notice from the Listing Qualifications Department of The Nasdaq Stock Market LLC (“Nasdaq”) indicating that because the closing bid price for the Company’s common stock had closed below $ 1.00 per share for 30 consecutive business days, the Company no longer complied with the minimum bid price requirement pursuant to Nasdaq Listing Rule 5550(a)(2) (the “Minimum Bid Requirement”). On January 8, 2024, the Company effected a 1-for-20 reverse stock split of its issued and outstanding common stock (the "Reverse Stock Split"). As a result of the Reverse Stock Split, the Company regained compliance with the Nasdaq listing rules. Each of the Company’s shareholders received one new share of common stock for every 20 shares such shareholder held immediately prior to the effective time of the Reverse Stock Split. The Reverse Stock Split affected all the Company’s issued and outstanding shares of common stock equally. The par value and authorized shares of the Company's common stock was not adjusted as a result of the Reverse Stock Split. The Reverse Split also affected the Company’s outstanding common stock options and warrants, and resulted in the shares underlying such instruments being reduced and the exercise price being increased proportionately. Unless otherwise noted, all common stock shares, common stock per share data, common stock options and warrants included in these consolidated financial statements, including the exercise price of such equity instruments, as applicable, have been retrospectively adjusted to reflect the effect of the Reverse Stock Split for all periods presented. Use of Estimates The Company’s consolidated financial statements are prepared in accordance with GAAP. The preparation of the Company’s consolidated financial statements and accompanying notes requires it to make estimates and assumptions that impact the reported amounts of assets, liabilities, revenues and expenses and the disclosure of contingent assets and liabilities. Significant estimates consist of accruals for research and development costs. Although these estimates are based on the Company’s knowledge of current events and actions it may undertake in the future, actual results may ultimately materially differ from these estimates and assumptions. Cash and Cash Equivalents The Company considers all highly liquid investments with maturities of three months or less when purchased to be cash equivalents. Cash and cash equivalents consist of Level 1 financial instruments in the fair value hierarchy (see Note 6 – Fair Value) and include cash in readily available checking accounts, money market accounts and commercial paper. Short-term Investments Short-term investments consist of U.S. treasury notes and bills, certificates of deposit, commercial paper and U.S. government sponsored enterprise securities with maturities of less than one year from the balance sheet date and are debt securities considered to be Level 1 and Level 2 financial instruments in the fair value hierarchy (see Note 6 – Fair Value). The Company determines the appropriate classification of marketable securities at the time of purchase and reevaluates such designation at each balance sheet date. The Company has classified all of its marketable securities at December 31, 2023 and 2022 as “available-for-sale” pursuant to ASC 320 Investments – Debt and Equity Securities . The Company records available-for-sale securities at fair value as determined by prices for identical or similar securities, with the unrealized gains and losses included as a separate component of other accumulated comprehensive income (loss). In accordance with policy, the Company does not invest in or hold equity securities in its investment portfolio. The Company adjusts the cost of available-for-sale debt securities for amortization of premiums or accretion of discounts to maturity. The Company includes interest and dividends on securities classified as available-for-sale in interest income. Such amortization and accretion are included in interest income. The cost of securities sold is based on the specific identification method. Realized gains or losses on available-for-sale securities are determined using the specific identification method and net realized gains and losses are included in interest income. The Company records unrealized gains and losses on available-for-sale marketable securities as a component of other comprehensive loss within the statements of comprehensive loss and as a separate component of stockholders’ equity on the balance sheets. The Company elected the practical expedient to exclude the applicable accrued interest from both the fair value and amortized costs basis of available-for-sale securities for purposes of identifying and measuring an impairment. Accrued interest receivable on available-for-sale securities is recorded in short-term investments in the accompanying consolidated balance sheets. The Company’s accounting policy is to not measure an allowance for credit loss for accrued interest receivable and to write-off any uncollectible accrued interest receivable as a reversal of interest income in a timely manner, which the Company considers to be in the period in which the Company determines the accrued interest will not be collected. The Company evaluates short-term investments for other-than-temporary impairment at the balance sheet date. Factors considered in determining whether a loss is other-than temporary include how significant the decline in value is as a percentage of the original cost, the length of time and extent to which fair value has been less than the cost basis, the financial condition of the issuer, and the Company’s intent and ability to hold the investment until recovery of its amortized cost basis. The Company intends, and has the ability, to hold any investments in unrealized loss positions until their amortized cost basis has been recovered. As of December 31, 2023 and 2022, there were no impairment charges on short-term investments. The Company obtains the fair value of its available-for-sale marketable securities from a professional pricing service. The fair values of available-for-sale marketable securities are validated by comparing the fair values reported by the professional pricing service to quoted market prices or to fair values obtained from the custodian bank. The service provider values the securities using a hierarchical security pricing model that relies primarily on valuations provided by an industry-recognized valuation service or mathematical calculations. Such valuations may be based on trade prices in active markets for identical assets or liabilities (Level 1 inputs) or valuation models using inputs that are observable either directly or indirectly (Level 2 inputs), such as quoted prices for similar assets or liabilities, yield curves, credit spreads, current market and contractual prices for the underlying instruments or debt, as well as other relevant economic measures. Deferred Compensation Deferred compensation represents the accrual of retention bonuses for certain executives and certain other members of senior management. The retention bonuses were entered into in connection with the waiver of annual cash performance bonuses of such personnel for the year ended December 31, 2023 and a temporary reduction of the chief executive officer’s salary from April 2023 through December 2024. Concentration of Credit Risk Financial instruments that potentially subject the Company to significant concentrations of credit risk consist primarily of cash, cash equivalents and short-term investments. The Company maintains deposits in federally insured financial institutions in excess of federally insured limits. The Company has not experienced any losses in such accounts and believes it is not exposed to significant risk on its cash balances due to the financial position of the depository institution in which those deposits are held. Additionally, the Company established guidelines regarding approved investments and maturities of investments, which are designed to maintain safety and liquidity. Patent Costs Costs related to filing and pursuing patent applications are recorded as general and administrative expense and expensed as incurred since recoverability of such expenditures is uncertain. Research and Development Expenses and Accruals Research and development expenses consist of costs incurred for the Company’s own and for sponsored and collaborative research and development activities. Research and development costs are expensed as incurred and include manufacturing process development costs, manufacturing costs, costs associated with preclinical studies and clinical trials, regulatory and medical affairs activities, quality assurance activities, salaries and benefits, including stock-based compensation, fees paid to third-party consultants, license fees and overhead. The Company has entered into various research and development contracts with research institutions, clinical research organizations, clinical manufacturing organizations and other companies. Payments for these activities are based on the terms of the individual agreements, which may differ from the pattern of costs incurred, and payments made in advance of performance are reflected in the accompanying consolidated balance sheets as prepaid and other assets or accrued liabilities. The Company records accruals for estimated costs incurred for ongoing research and development activities. When evaluating the adequacy of the accrued liabilities, which include clinical trial accruals, the Company analyzes progress of the services, including the phase or completion of events, invoices received and contracted costs. Significant judgments and estimates may be made in determining the prepaid or accrued balances at the end of any reporting period. Actual results could differ from the Company’s estimates. Fair Value Measurements The accounting guidance defines fair value, establishes a consistency framework for measuring fair value and expands disclosure for each major asset and liability category measured at fair value on either a recurring basis or nonrecurring basis. Fair value is defined as an exit price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants on the measurement date. Accounting guidance establishes a three-tier fair value hierarchy that requires an entity to maximize the use of observable inputs and minimize the use of unobservable inputs when measuring fair value. These tiers are based on the source of the inputs and are as follows: Level 1: Observable inputs such as quoted prices in active markets for identical assets or liabilities. Level 2: Inputs other than quoted prices in active markets that are observable either directly or indirectly. Level 3: Unobservable inputs in which there is little or no market data, which require the reporting entity to develop its own assumptions. The Company’s financial instruments include cash, cash equivalents, short-term investments, prepaid expenses and other assets, accounts payable, accrued expenses, and accrued compensation. The carrying amounts of the Company’s current financial assets and liabilities are considered to be representative of their respective fair values because of the short-term nature of those instruments. The Company has short-term investments that are measured at fair value on a recurring basis. No transfers between levels have occurred during the periods presented (see Note 6). Revenue Recognition The Company generates revenue from certain grant awards or a research subaward (the “Grant Awards”) (see Note 5), which provides the Company with payments in return for certain research and development activities over a contractually defined period. Revenue from such Grant Awards is recognized in the period during which the related qualifying services are rendered and costs are incurred, provided that the applicable conditions under the Grant Awards have been met. The Grant Awards are on a best-efforts basis and do not require scientific achievement as a performance obligation. The Grant Awards are non-refundable. The costs associated with the Grant Awards are expensed as incurred and reflected as a component of research and development expense in the accompanying consolidated statements of operations. Funds received from the Grant Awards are recorded as revenue as the Company is the principal participant in the arrangement because the activities under the Grant Awards are part of the Company’s development programs. In those instances where the Company first receives consideration in advance of providing underlying services, the Company classifies such consideration as deferred revenue until (or as) the Company provides the underlying services. In those instances where the Company first provides the underlying services prior to its receipt of consideration, the Company records a grant receivable. Stock-Based Compensation Stock-based compensation expense represents the fair value of equity awards, on the grant date, recognized in the period using the Black-Scholes option pricing model. The Company recognizes expense for awards with graded vesting schedules over the requisite service period of the awards (usually the vesting period) on a straight-line basis. For equity awards for which vesting is subject to performance-based milestones, the expense is recorded over the remaining service period after the point when the achievement of the milestone is probable. The Company recognizes forfeitures for all awards as such forfeitures occur. Income Taxes The Company accounts for income taxes under the asset and liability method, which requires the recognition of deferred tax assets and liabilities for the expected future tax consequences of events that have been included in the consolidated financial statements. Under this method, deferred tax assets and liabilities are determined on the basis of the differences between the financial statements and tax basis of assets and liabilities using enacted tax rates in effect for the year in which the differences are expected to reverse. The effect of a change in tax rates on deferred tax assets and liabilities is recognized in income in the period that includes the enactment date. The Company recognizes net deferred tax assets to the extent that the Company believes these assets are more likely than not to be realized. In making such a determination, management considers all available positive and negative evidence, including future reversals of existing taxable temporary differences, projected future taxable income, tax-planning strategies, and results of recent operations. If management determines that the Company would be able to realize its deferred tax assets in the future in excess of their net recorded amount, management would make an adjustment to the deferred tax asset valuation allowance, which would reduce the provision for income taxes. Segment Reporting Operating segments are identified as components of an enterprise about which separate discrete financial information is available for evaluation by the chief operating decision-maker in making decisions regarding resource allocation and assessing performance. The Company views its operations and manages its business in one operating segment in the United States. Net Loss Per Share Basic net loss per share is computed by dividing the net loss by the weighted-average number of common shares outstanding for the period, without consideration for potentially dilutive securities and adjusted for the weighted-average number of common shares outstanding that are subject to repurchase. Diluted net loss per share is computed by dividing the net loss by the weighted-average number of shares of common stock and dilutive common stock equivalents outstanding for the period determined using the treasury-stock and if-converted methods. For all periods presented, there is no difference in the number of shares used to calculate basic and diluted shares outstanding as inclusion of the potentially dilutive securities would be antidilutive. Potentially dilutive securities not included in the calculation of diluted net loss per share, because to do so would be anti-dilutive, are as follows (in common stock equivalent shares): December 31, 2023 2022 Warrants to purchase common stock 170,521 170,521 Common stock options 548,073 425,785 Restricted stock units 18,557 50,454 737,151 646,760 Recently Adopted Accounting Pronouncements In June 2016, the FASB issued ASU 2016-13, Financial Instruments – Credit Losses: Measurement of Credit Losses on Financial Statements (Topic 326), which intends to improve financial reporting by requiring earlier recognition of credit losses on certain financial assets, such as available-for-sale debt securities. Topic 326 amends guidance on reporting credit losses for assets held at amortized cost basis and available-for-sale debt securities. For assets held at amortized cost basis, Topic 326 eliminates the probable initial recognition threshold in current GAAP and, instead, requires an entity to reflect its current estimate of all expected credit losses. The allowance for credit losses is a valuation account that is deducted from the amortized cost basis of the financial assets to present the net amount expected to be collected. For available-for-sale debt securities, credit losses should be measured in a manner similar to current GAAP, however Topic 326 will require that credit losses be presented as an allowance rather than as a write-down. This ASU update affects entities holding financial assets and net investment in leases that are not accounted for at fair value through net loss. This update is effective for the Company and was adopted on January 1, 2023, which did not have a material impact on its consolidated financial statements. Accounting Standards Not Yet Adopted In November 2023, the FASB issued ASU 2023-07, Segment Reporting – Improvements to Reportable Segment Disclosures (Topic 280), which intends to improve financial reporting primarily through enhanced disclosures about significant segment expenses. Topic 280 includes amendments which a) introduce a new requirement to disclose significant segment expenses regularly provided to the chief operating decision maker (CODM), b) extend  certain annual disclosures to interim periods, c) clarify single reportable segment entities must apply ASC 280 in its entirety, d) permit more than one measure of segment profit or loss to be reported under certain conditions, and e) require disclosure of the title and position of the CODM. This update is effective for all public entities beginning after December 15, 2023. The Company is currently evaluating the impact of this guidance on its consolidated financial statements. In December 2023, the FASB issued ASU 2023-09, Income Tax – Improvements to Income Tax Disclosures, which intends to improve financial reporting primarily through enhanced disclosures about significant segment expenses. The standard requires disaggregated information about a reporting entity’s effective tax rate reconciliation as well as information on income taxes paid. The standard is intended to benefit investors by providing more detailed income tax disclosures that would be useful in making capital allocation decisions. This update is effective for all public entities beginning after December 15, 2024. The Company is currently evaluating the impact of this guidance on its consolidated financial statements.

Balance Sheet Details

Balance Sheet Details	12 Months Ended
	Dec. 31, 2023
Payables and Accruals [Abstract]
Balance Sheet Details	2. Balance Sheet Details Prepaid and other consist of the following (in thousands): December 31, December 31, 2023 2022 Research and development $ 312 $ — Clinical trials 294 2,616 Insurance 478 669 Other prepaid expenses 88 103 Related party receivable (see Note 4) 139 — Grant and other receivable 493 178 $ 1,804 $ 3,566 Accrued liabilities consist of the following (in thousands): December 31, December 31, 2023 2022 Research and development $ 146 $ 972 Clinical trials 2,018 868 Legal fees 134 138 Compensation 1,579 2,691 Other — 9 $ 3,877 $ 4,678

Short-term Investments

Short-term Investments	12 Months Ended
	Dec. 31, 2023
Investments, Debt and Equity Securities [Abstract]
Short-term Investments	3. Short-term Investments The Company invests in available-for-sale marketable securities consisting of money market funds, commercial paper, certificates of deposit, U.S. Treasury securities and U.S. government sponsored enterprise securities. Available-for-sale marketable securities with original maturities of more than three months from the date of purchase as of December 31, 2023 have been classified as short-term investments and are measured at a fair value on a recurring basis, and were as follows (in thousands): Maturity (in years) Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Market Value As of December 31, 2023 Short term investments: U.S. Treasury debt securities 1 or less $ 23,840 $ 4 $ — $ 23,844 Commercial Paper 1 or less 2,738 — ( 1 ) 2,737 U.S. Government Agency 1 or less 977 — — 977 Total short-term investments $ 27,555 $ 4 $ ( 1 ) $ 27,558 Available-for-sale marketable securities with original maturities of more than three months from the date of purchase as of December 31, 2022 have been classified as short-term investments and are measured at a fair value on a recurring basis, and were as follows (in thousands): Maturity (in years) Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Market Value As of December 31, 2022 Short term investments: U.S. Treasury debt securities 1 or less $ 21,681 $ 7 $ — $ 21,688 Commercial Paper 1 or less 2,936 — — 2,936 U.S. Government Agency 1 or less 1,956 2 — 1,958 Total short-term investments $ 26,573 $ 9 $ — $ 26,582 The Company determined there were no other-than-temporary declines in the value of any available-for-sale securities as of December 31, 2023. All the Company’s available-for-sale marketable securities mature within one year. The Company has no allowance for credit losses as of December 31, 2023 and 2022. During the years ended December 31, 2023, and 2022, the Company recognized an unrealized loss of $ 6,000 and an unrealized gain of $ 9,000 , respectively, in the accompanying consolidated statements of operations and comprehensive loss. Accrued interest receivable on available-for-sale securities was $ 15,000 and $ 116,000 at December 31, 2023 and 2022, respectively. We have no t written off any accrued interest receivable in any of the periods presented in these consolidated financial statements.

Commitments, Contingencies and

Commitments, Contingencies and Related Party Transactions	12 Months Ended
	Dec. 31, 2023
Commitments and Contingencies Disclosure [Abstract]
Commitments, Contingencies and Related Party Transactions	4. Commitments, Contingencies and Related Party Transactions Lease Rent expense was $ 0.2 million for the years ended December 31, 2023 and 2022. From May 2019 through April 2022, the Company leased office space in San Diego, California. In April 2022, the Company entered into a sublease agreement for office space in San Diego, California which expired in July 2023 (the “San Diego Lease”). In May 2023, the Company entered into a lease agreement for the same office space which expires on September 30, 2025 . Base rent under such lease is approximately $ 145,000 annually and the monthly rent expense will be recognized on a straight-line basis over the effective term of the lease. The San Diego Lease is included in the accompanying consolidated balance sheet at the present value of the lease payments. As the San Diego Lease does not have an implicit interest rate, the present value reflects a 10.0 % discount rate which is the estimated rate of interest that the Company would have to pay in order to borrow an amount equal to the lease payments on a collateralized basis over a similar term and in a similar economic environment. As of December 31, 2023, the Company has recognized a net operating lease right-of-use asset and a lease liability of $ 0.3 million that matures in September 2025, which has a weighted average remaining lease term of 1.8 years. As of December 31, 2022, the Company’s lease had a weighted average remaining lease term of 0.6 years. Maturity of lease liabilities Operating 2024 $ 196 2025 150 Total lease payments 346 Less imputed interest ( 28 ) Total lease liability 318 Less current portion of lease liability ( 173 ) Lease liability, long-term $ 145 Related Party Transactions Effective in September 2019, the Company and Shanghai Pharmaceutical (USA) Inc. (“SPH USA”) entered into a Materials Supply and Services Agreement (“SPH USA Services Agreement”), pursuant to which the Company and SPH USA will execute various statements of work for the transfer to SPH USA of key reagents and other materials, and for the supply of certain services by the Company to SPH USA, as contemplated under and in furtherance of the License and Development Agreement between the Company and SPH USA effective as of November 2018. During 2023, the Company sold $ 0.5 million of materials to SPH USA which was recorded as an offset to ONCT-216 operating expenses. As of December 31, 2023 and 2022, the Company had amounts receivable of $ 0.1 million and none , respectively, from SPH USA related to license agreement. SPH USA is the Company’s largest stockholder and an affiliate of one of the Company’s directors.

License, Collaboration, Grants,

License, Collaboration, Grants, Research Subaward Agreement and CVR Agreements	12 Months Ended
	Dec. 31, 2023
Organization, Consolidation and Presentation of Financial Statements [Abstract]
License, Collaboration, Grants, Research Subaward Agreement and CVR Agreements	5. License, Collaboration, Grants, Research Subaward and CVR Agreements University of Tennessee Research Foundation (“UTRF”) In March 2015, and as amended and restated in March 2022 and August 2022, the Company and UTRF entered into a license agreement (the “DAARI License Agreement”) pursuant to which the Company was granted exclusive worldwide rights in all existing selective androgen receptor degrader technologies owned or controlled by UTRF, including all improvements thereto, which is now known as the dual action androgen receptor inhibitor, or DAARI program. Under the DAARI License Agreement, the Company is obligated to employ active, diligent efforts to conduct preclinical research and development activities for the DAARI program to advance one or more lead compounds into clinical development. The Company is also obligated to pay UTRF annual license maintenance fees, low single-digit royalties on net sales of products and additional royalties on sublicense revenues, depending on the state of development of a clinical product candidate at the time it is sublicensed. The Company recorded research and development expenses under this agreement of $ 0.2 million and $ 0.3 million for each of the years ended December 31, 2023 and 2022, respectively. Agreements with the Regents of the University of California (the “Regents”) In March 2016, and as amended and restated in August 2018, and as amended thereafter through January 2024, the Company entered into a license agreement (as amended and restated, the “Regents License Agreement”) for the development, manufacturing and distribution rights related to the development and commercialization of ROR1 related naked antibodies, antibody fragments or synthetic antibodies, and genetically engineered cellular therapy. The Regents License Agreement provides for the following: (i) in May 2016, an upfront license fee of $ 0.5 million was paid and 5,355 shares of common stock were issued, (ii) $ 25,000 in annual license maintenance fees commencing in 2017, (iii) reimbursement of certain annual patent costs, (iv) certain development and regulatory milestones aggregating from $ 20.1 million to $ 24.5 million, on a per product basis, (v) certain worldwide sales milestones based on achievement of tiered revenue levels aggregating $ 75.0 million, (vi) low single-digit royalties, including potential future minimum annual royalties, on net sales of each target, and (vii) minimum diligence to advance licensed assets consisting of at least $ 1.0 million in development spend annually through 2021. Under the Regents License Agreement, the Company recorded: (i) $ 25,000 in license maintenance fees as research and development expense for each of the years ended December 31, 2023 and 2022, and (ii) approximately $ 0.1 million in patent costs as general and administrative expense for each of the years ended December 31, 2023 and 2022. The Regents License Agreement will expire upon the later of the expiration date of the longest-lived patent rights or the 15 th anniversary of the first commercial sale of a licensed product. The Regents may terminate the Regents License Agreement if: (i) a material breach by the Company is not cured within a reasonable time, (ii) the Company files a claim asserting the Regents licensed patent rights are invalid or unenforceable and (iii) the Company files for bankruptcy. The Company may terminate the agreement at any time upon at least 60 days’ written notice. Effective January 1, 2022, the Company entered into a Research Agreement (the “Research Agreement”) with the Regents for further research on a ROR1 therapeutic development program. Under this four-year agreement that expires on December 31, 2025, the Regents will receive payments aggregating $ 1.6 million, with quarterly payments of $ 125,000 in 2022, $ 131,250 in 2023, and $ 137,813 in 2024 and 2025. The Company recorded $ 0.5 million in research and development expense under this agreement in each of the years ended December 31, 2023 and 2022. The California Institute for Regenerative Medicine (“CIRM”) Award In August 2017, and as amended and restated in December 2020, CIRM awarded an $ 18.3 million grant to researchers at UC San Diego to advance the Company’s Phase 1/2 clinical trial evaluating zilovertamab in combination with ibrutinib for the treatment of patients with B-cell lymphoid malignancies, including MCL and CLL. This study is known as CIRM-0001, or Cirmtuzumab and Ibrutinib for Relapsed Lymphoma or Leukemia (the “CIRLL study”). The Company: (i) conducted this study in collaboration with UC San Diego, (ii) received $ 14.5 million in development milestones under research subaward agreements during the award project period from October 1, 2017 through March 31, 2022, (iii) was committed to and met certain co-funding requirements, and (iv) was required to provide UC San Diego progress and financial update reports throughout the award period. The subaward does not bear a royalty payment commitment, nor is the subaward otherwise refundable. As of December 31, 2023, the Company believes it has met its obligations under the CIRM award and UC San Diego subawards. The National Institutes of Health (“NIH”) Grant Awards The NIH has awarded the Company three research and development grants for up to $ 4.0 million to support preclinical activities for the Company’s ONCT-534 and ONCT-216 programs, including $ 1.0 million payable to subawardees. Under the terms of the grant awards, the Company is entitled to receive reimbursement in arrears of incurring allowable expenditures. The earned NIH funds are non-refundable and the Company is required to provide periodic progress performance reports. During the years ended December 31, 2023 and 2022, the Company received $ 0.4 million and $ 1.2 million, respectively, in award payments from the NIH. During the years ended December 31, 2023 and 2022, the Company recorded $ 0.8 million and $ 1.1 million, respectively, in NIH grant revenue and had $ 0.5 million and $ 0.1 million in unbilled receivables as of December 31, 2023 and 2022, respectively, which has been included in prepaid and other assets. SPH USA, a Related Party License and Development Agreement (“LDA”) In November 2018, and as amended in August 2020, the Company entered into the LDA with SPH USA for: (i) the territory of the People’s Republic of China, Hong Kong, Macau, and Taiwan (“Greater China”), and (ii) rights to manufacture, develop, market, distribute and sell all of the Company’s product candidates under the Georgetown License Agreement and the Regents License Agreement (exclusive to Greater China only). Under the LDA, SPH USA is solely responsible for: (a) all preclinical and clinical development activities required in order to obtain regulatory approval in Greater China for such product candidates, (b) any third-party license milestone or royalty payments owed under the Georgetown License Agreement and the Regents License Agreement, and (c) paying the Company a low single digit royalty on net sales in the territory. The LDA will expire upon the expiration of the last royalty term for the last licensed product. The LDA may be terminated by: (i) SPH USA on a country/region-by-country/region or product by product basis with 180 days written notice, (ii) either party upon material breach that is not cured within 90 days, and (iii) either party in the event the other party declares insolvency or bankruptcy. There has been no significant activity under this agreement for the years ended December 31, 2023 and 2022. See Note 4. Contingent Value Rights Agreement (“CVR Agreement”) Pursuant to the GTx merger agreement entered into in June 2019 (the “Merger”), the Company, a representative of holders of the CVRs, and Computershare, Inc. as rights agent entered into the CVR Agreement. Pursuant to the CVR Agreement, the Company’s stockholders of record as of immediately prior to the Merger received one CVR for each share of the Company’s common stock held immediately prior to the Merger. As amended on November 1, 2021, the CVR Agreement entitles holders of CVRs to receive: (i) 50% of certain net proceeds received by the Company during the 15 -year period after the closing of the Merger (the “CVR Term”) from a transaction, if any, resulting in the grant, sale, or transfer of DAARI technology to a third party that occurs during the 10 -year period after the closing of the Merger (or in the 11th year if based on a term sheet approved during the initial 10-year period); and (ii) 5 % of net sales of products by Parent or its affiliates during the CVR Term incorporating the DAARI technology. As of December 31, 2023, no transactions or net sales relating to the DAARI technology had occurred.

Fair Value

Fair Value	12 Months Ended
	Dec. 31, 2023
Fair Value Disclosures [Abstract]
Fair Value	6. Fair Value As of December 31, 2023 and December 31, 2022, the following fair value hierarchy tables presents the Company’s financial assets measured at fair value on a recurring basis (in thousands): Total Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) As of December 31, 2023 Short term investments: U.S. Treasury debt securities $ 23,844 $ 10,912 $ 12,932 $ — Commercial Paper 2,737 — 2,737 — U.S. Government Agency 977 — 977 — Total short-term investments $ 27,558 $ 10,912 $ 16,646 $ — Total Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) As of December 31, 2022 Short term investments: U.S. Treasury debt securities $ 21,688 $ 21,688 $ — $ — Commercial Paper 2,936 — 2,936 — U.S. Government Agency 1,958 — 1,958 — Total short-term investments $ 26,582 $ 21,688 $ 4,894 $ — Valuation of short-term investments The Company classifies its money market funds, treasury notes and treasury bills as Level 1 assets under the fair value hierarchy, as these assets have been valued using quoted market prices for identical assets in active markets without any valuation adjustment. The Company classifies its commercial paper and U.S. government sponsored enterprise securities as Level 2 assets under the fair value hierarchy, as these assets have been valued using information obtained through a third-party pricing service at each balance sheet date, using observable market inputs that may include trade information, broker or dealer quotes, bids, offers, or a combination of these data sources. The Company does not hold any short-term investments classified as Level 3, which are securities valued using unobservable inputs. The Company’s policy is to recognize transfers between levels of the fair value hierarchy on the date of the event or change in circumstances that caused the transfer. The Company did not transfer any investment securities between the classification levels during the years ended December 31, 2023 and 2022.

Stockholders' Equity

Stockholders' Equity	12 Months Ended
	Dec. 31, 2023
Equity [Abstract]
Stockholders' Equity	7. Stockholders’ Equity ATM Program In December 2021, the Company entered into an Open Market Sale Agreement SM (the “Sales Agreement”) with Jefferies LLC, pursuant to which the Company is able to offer and sell, from time to time in its sole discretion, shares of its common stock having an aggregate offering price of up to $ 50.0 million. The Company has no obligation to sell any shares under the Sales Agreement and may at any time suspend solicitation and offers under the Sales Agreement. During the years ended December 31, 2023 and 2022, the Company sold 55,274 and 402,068 shares of common stock for net proceeds of $ 1.2 million and $ 9.6 million, respectively. Common Stock Warrants A summary of warrant activity and changes in warrants outstanding is presented below: Number of Weighted-Average Weighted-Average Remaining Contractual Term Balance Outstanding - December 31, 2021 211,746 $ 210.00 3.31 Expired ( 41,225 ) 772.80 — Balance Outstanding - December 31, 2022 170,521 74.00 2.94 Issued / Exercised / Forfeited / Expired — — — Balance Outstanding - December 31, 2023 170,521 $ 74.00 1.94 As of December 31, 2023 and 2022, all warrants met the criteria for classification in stockholders’ equity. Equity Incentive Plans Contemporaneous with the Merger closing: (i) Oncternal’s 2015 Equity Incentive Plan, as amended (“2015 Plan”) was assumed by the Company, and (ii) the Company adopted the 2019 Incentive Award Plan (“2019 Plan”) under which the sum of: (a) 97,708 shares of common stock, and (b) an annual increase on the first day of each calendar year beginning January 1, 2020, and ending on and including January 1, 2029, equal to the lesser of (A) 5 % of the aggregate number of shares of common stock outstanding on the final day of the immediately preceding calendar year and (B) such smaller number of shares of common stock as is determined by the Board, are reserved for issuance. In July 2015, Oncternal adopted the 2015 Plan which provided for the issuance of shares of common stock for incentive stock options, non-statutory stock options, restricted stock awards, restricted stock unit awards and other stock awards to its employees, members of its board of directors and consultants. In general, the options issued under the 2015 Plan expire ten years from the date of grant and vest over a four-year period. Certain grants vest based on the achievement of development or regulatory milestones. The 2015 Plan was terminated as to new grant awards in June 2019. The 2019 Plan provides for the issuance of shares of common stock for incentive stock options, non-statutory stock options, restricted stock awards, restricted stock unit awards and other stock awards to its employees, members of its board of directors and consultants. In general, the stock options issued under the 2019 Plan expire ten years from the date of grant and vest over a four-year period. Certain stock option grants vest based on the achievement of development or regulatory milestones. The 2019 Plan allows for the early exercise of all stock option grants if authorized by the board of directors at the time of grant. In February 2021, the Company’s board of directors adopted the 2021 Employment Inducement Incentive Award Plan (the “Inducement Plan”). The Inducement Plan is a non-shareholder approved stock plan adopted pursuant to the “inducement exception” provided under Nasdaq listing rules. The Inducement Plan is used exclusively for the issuance of non-statutory stock options to certain new hires who satisfy the requirements to be granted inducement grants under Nasdaq rules as an inducement material to the individual’s entry into employment with the Company. The terms of the Inducement Plan are substantially similar to the terms of the 2019 Plan. As amended in May 2021 and December 2021, the Company has reserved 140,000 shares for the issuance of common stock under the Inducement Plan. A summary of the Company’s stock option activity under the 2015 Plan, 2019 Plan and Inducement Plan is as follows: Number of Weighted- Weighted- Aggregate Outstanding at December 31, 2022 425,766 $ 83.25 Granted 173,794 $ 16.49 Cancelled ( 51,487 ) $ 69.09 Outstanding at December 31, 2023 548,073 $ 56.51 7.4 $ 155,648 Options vested and expected to vest at December 31, 2023 548,073 $ 56.51 7.4 $ 155,648 Vested and exercisable at December 31, 2023 279,184 $ 74.09 7.1 $ 68,418 The weighted average grant date fair value per share of option grants for the years ended December 31, 2023 and 2022 was $ 13.33 and $ 25.81 per share, respectively. The intrinsic value is calculated as the difference between the fair value of the Company’s common stock at December 31, 2023 of the option exercise and the exercise price of that stock option. There were no stock options exercised during the years ended December 31, 2023 and 2022. In October 2023, the Company repriced certain stock options held by employees and consultants. The repricing action was taken by the Company's board of directors to align the stock options with current market conditions and to retain key employees. The board of directors determined that the original exercise prices of the stock options were no longer reflective of the current market value of the Company's common stock. As a result of the repricing, the exercise prices of the stock options were adjusted to reflect the fair value of the Company's common stock as of October 2, 2023. The vesting schedules and other terms of the stock options were unchanged. The repricing was implemented through an amendment to the existing stock option agreements, which was approved by the board of directors. The repriced stock options are subject to terms such that any exercises prior to a premium end date shall use the original exercise price prior to the repricing amendment. The fair value of the repriced stock options was determined using the Black-Scholes option-pricing model. The incremental fair value of vested stock options resulted in a one-time charge to stock-based compensation expense of $ 0.4 million. The incremental fair value of unvested options of $ 0.4 million will be recognized over the remaining vesting period of the stock options. Restricted Stock Unit Awards Restricted stock unit awards (“RSUs”) are rights to receive shares of the Company’s common stock upon satisfaction of specific vesting conditions. The Company began issuing RSUs in the first quarter of 2022. The RSUs generally vest over an 18 month to two-year period. RSUs activity under the 2019 Plan is summarized as follows: Number of Restricted Stock Units Weighted-Average Remaining Contractual Term (in years) Weighted-Average Grant Date Fair Value Nonvested at December 31, 2022 50,438 $ 32.80 Granted — Vested ( 30,537 ) $ 35.56 Forfeited/ Repurchased ( 1,344 ) $ 32.16 Nonvested at December 31, 2023 18,557 0.1 $ 28.32 Units expected to vest as of December 31, 2023 18,557 0.1 $ 28.32 The weighted average grant date fair value per share of RSU grants for the years ended December 31, 2023 and 2022 was none and $ 33.01 per share, respectively. The total fair value of shares vested during the year ended December 31, 2023 was $ 0.4 million. The total fair value of shares vested during the year ended December 31, 2022 was nominal. Stock-Based Compensation Expense The weighted-average assumptions used in the Black-Scholes option pricing model to determine the fair value of stock option grants were as follows: Years Ended 2023 2022 Risk-free interest rate 4.1 % 2.2 % Expected volatility 100.6 % 100.5 % Expected term (in years) 6.0 6.1 Expected dividend yield — % — % Expected volatility. The expected volatility assumption is based on a blend of volatilities of the Company’s share price and a peer group of similar companies whose share prices are publicly available. The volatility of the Company’s shares price was measured using the closing share price beginning June 10, 2019, the date of the closing of the Merger, through the current period. The peer group was developed based on companies in the life sciences industry with comparable characteristics to the Company including enterprise value, risk profiles, position within the industry, and with historical share price information sufficient to meet the expected life of the stock-based awards. The Company will continue to apply this process until a sufficient amount of historical information regarding the volatility of its own stock price becomes available. Expected term. The expected term represents the period of time that options are expected to be outstanding. Due to limited historical exercise behavior, it determined the expected life assumption using the simplified method for employees, which is an average of the contractual term of the option and its vesting period. The expected term for nonemployee options is generally the remaining contractual term. Risk-free interest rate. The risk-free interest rate is based on the implied yield on the U.S. Treasury securities with a maturity date similar to the expected term of the associated stock option award. Expected dividend yield. The Company bases the expected dividend yield assumption on the fact that it has never paid cash dividends and has no present intention to pay cash dividends and, therefore, used an expected dividend yield of zero. RSUs represent rights to receive shares of common stock contingent upon satisfaction of specific vesting conditions. The stock-based compensation expense for these awards was determined using the closing price on the grant date applied to the total number of shares that were anticipated to fully vest. Stock-based compensation expense recognized for all equity awards has been reported in the statements of operations as follows (in thousands): Years Ended 2023 2022 Research and development $ 4,064 $ 4,055 General and administrative 3,436 3,376 $ 7,500 $ 7,431 As of December 31, 2023, the unrecognized compensation cost related to non-vested stock options was $ 7.7 million, which is expected to be recognized over a weighted-average period of 1.9 years. As of December 31, 2023, the unrecognized compensation cost related to non-vested restricted stock units was nominal, which is expected to be recognized in the first quarter of 2024. Common Stock Reserved for Future Issuance Common stock reserved for future issuance is as follows: December 31, 2023 2022 Common stock warrants 170,521 170,521 Common stock options outstanding 548,073 425,785 Restricted stock unit awards unvested and outstanding 18,557 50,454 Common stock available for issuance under Inducement Plan and 2019 Plan 94,909 61,500 832,060 708,260

Income Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2023
Income Tax Disclosure [Abstract]
Income Taxes	8. Income Taxes A reconciliation of the Company’s effective tax rate and federal statutory tax rate is as follows (in thousands): Years Ended 2023 2022 Federal income taxes $ ( 8,290 ) $ ( 9,276 ) State income taxes, net of federal benefit ( 58 ) ( 2,820 ) Permanent items 8 3 Stock based compensation 1,172 831 Research and development credit carryforwards ( 2,910 ) ( 4,747 ) State rate change 1,222 — Other, net 196 ( 48 ) Change in valuation allowance 8,660 16,057 Provision for income taxes $ — $ — Significant components of the Company’s net deferred tax assets are as follows (in thousands): December 31, 2023 2022 Deferred tax assets: Net operating loss carryforwards $ 29,997 $ 27,889 Research and development credit carryforwards 10,958 7,804 Accrued expenses 676 860 Capitalized research and development costs 22,501 19,153 Stock based compensation 2,406 2,188 Other, net 90 29 Total deferred tax assets 66,628 57,923 Valuation allowance ( 66,561 ) ( 57,899 ) Deferred tax assets, net 67 24 Deferred tax liabilities: Right of use asset ( 67 ) ( 24 ) Total deferred tax liabilities ( 67 ) ( 24 ) Net deferred tax assets $ — $ — As of December 31, 2023 and 2022, management assessed the realizability of deferred tax assets and evaluated the need for a valuation allowance for deferred tax assets on a jurisdictional basis. This evaluation utilizes the framework contained in ASC 740, Income Taxes, wherein management analyzes all positive and negative evidence available at the balance sheet date to determine whether all or some portion of the Company's deferred tax assets will not be realized. Under this guidance, a valuation allowance must be established for deferred tax assets when it is more-likely-than-not that the asset will not be realized. In assessing the realization of the Company's deferred tax assets, management considers all available evidence, both positive and negative. In concluding on the evaluation, management placed significant emphasis on guidance in ASC 740, which states that “a cumulative loss in recent years is a significant piece of negative evidence that is difficult to overcome.” Based upon available evidence, it was concluded on a more-likely-than-not basis that all deferred tax assets were not realizable as of December 31, 2023. Accordingly, a valuation allowance of $ 66.6 million has been recorded to offset this deferred tax asset. The valuation allowance increased by $ 8.7 million and $ 16.1 million for the years ended December 31, 2023 and 2022, respectively. At December 31, 2023, the Company had federal and state net operating loss (NOL) carryforwards of approximately $ 119.5 million and $ 70.4 million, respectively. Of the federal and state net operating losses at December 31, 2023, $ 93.2 million and no ne, respectively, do not expire, and the remaining federal and state net operating loss carryforwards will begin expiring in 2033 and 2029 , respectively, unless previously utilized. At December 31, 2023, the Company also had federal and state research and development credit carryforwards of approximately $ 4.3 million and $ 2.9 million, respectively. The federal research and development credit carryforwards will begin expiring in 2034 unless previously utilized. The state research and development credits do not expire. Utilization of the net operating losses and credits may be subject to substantial annual limitations due to federal and state ownership change limitations provided by the Internal Revenue Code Section 382 and 383 and similar state provisions. Such annual limitations could result in the expiration of the net operating losses and credits before their utilization. The Company has not performed a Section 382 analysis to determine whether ownership changes will impact the use of net operating loss carryforwards and credits carryforwards and limit their ability to offset future taxable income. For financial statement purposes, the Company has included the federal and state net operating losses and credits in the schedule of deferred tax assets offset with a full valuation allowance. If eliminated, the related asset would be removed from the deferred tax asset schedule with a corresponding reduction in the valuation allowance. Due to the existence of the valuation allowance, limitations created by historical ownership changes will not impact the Company’s effective tax rate in the future. The Company recognizes a tax benefit from an uncertain tax position when it is more likely than not that the position will be sustained upon examination, including resolutions of any related appeals or litigation processes, based on the technical merits. Income tax positions must meet a more likely than not recognition at the effective date to be recognized. At December 31, 2023 and 2022, there were no unrecognized tax benefits recorded in the consolidated financial statements. The Company does not expect any material changes to unrecognized tax benefits within the next twelve months. The Company is subject to taxation in the United States federal and state jurisdictions. The Company’s 2014 through 2023 federal income tax and state income tax returns are subject to examination by federal and state tax authorities due to the carryforward of unutilized net operating losses and research and development credits. The Company is not currently under examination by any tax authority. The Company’s policy is to recognize interest and penalties related to income tax matters in income tax expense. The Company has no t recognized interest or penalties in its consolidated statements of operations since inception.

Description of Business, Basi_2

Description of Business, Basis of Presentation and Summary of Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2023
Accounting Policies [Abstract]
Principles of Consolidation	Principles of Consolidation The consolidated financial statements include the accounts of the Company and its wholly-owned subsidiaries, Oncternal Oncology, Inc. and Oncternal, Inc. All intercompany accounts and transactions have been eliminated in the preparation of the consolidated financial statements.
Going Concern	Going Concern The consolidated financial statements have been prepared assuming the Company will continue as a going concern, which contemplates the realization of assets and the satisfaction of liabilities in the normal course of business. From inception, the Company has devoted substantially all of its efforts to drug discovery and development and conducting preclinical studies and clinical trials. The Company has a limited operating history and the sales and income potential of the Company’s business and market are unproven. Successful transition to attaining profitable operations is dependent upon achieving a level of revenues adequate to support the Company’s cost structure. As of December 31, 2023, the Company had $ 34.3 million in cash, cash equivalents, and short-term investments, no debt and an accumulated deficit of $ 197.8 million. From its inception, the Company has incurred recurring operating losses and negative cash flows from operations. The Company has concluded that the balance of cash, cash equivalents and short-term investments will not be sufficient to fund its planned expenditures and meet its obligations for the twelve months following the financial statement issuance date without raising additional funding or making changes to its operating plans or programs to reduce expenses. As a result, there is substantial doubt about the Company’s ability to continue as a going concern for twelve months following the issuance date of these consolidated financial statements. The consolidated financial statements have been prepared assuming the Company will continue as a going concern and do not include any adjustments that might result from the outcome of this uncertainty. The Company expects to continue to incur net losses for the foreseeable future and believes it will need to raise substantial additional capital to accomplish its business plan over the next several years. The Company plans to continue to fund its losses from operations and capital funding needs through a combination of public or private equity or debt offerings or other sources, including potential collaborations, strategic alliances and other similar licensing arrangements in both the short term and long term. If the Company is unable to secure adequate additional funding, the Company may be forced to make reductions in spending, including potentially delaying, scaling back or eliminating certain of its pipeline development programs, extend payment terms with suppliers, or liquidate assets where possible. Any of these actions could materially harm the Company’s business, results of operations and future prospects. As of December 31, 2023, the Company had capacity to issue up to an additional $ 38.8 million of shares of common stock under its at-the-market (“ATM”) equity offering program. Through December 31, 2023, the Company has sold 457,342 shares of common stock for net proceeds of $ 10.8 million under the ATM program. There can be no assurance that the Company will be able to sell any additional shares of its common stock under the ATM program and no assurance regarding the price at which it will be able to sell any such shares, and any sales of shares of its common stock under the ATM program may be at prices that result in additional dilution to existing stockholders of the Company. The Company's ability to obtain additional financing (including through collaborating and licensing arrangements) will depend on a number of factors, including, among others, its ability to generate positive data from its clinical trials and preclinical studies, the condition of the capital markets and the other risks, many of which are dependent on factors outside of its control. There can be no assurance as to the availability or terms upon which such financing and capital might be available in the future.
Nasdaq Listing and Reverse Stock Split	Nasdaq Listing and Reverse Stock Split On April 4, 2023, the Company received a written notice from the Listing Qualifications Department of The Nasdaq Stock Market LLC (“Nasdaq”) indicating that because the closing bid price for the Company’s common stock had closed below $ 1.00 per share for 30 consecutive business days, the Company no longer complied with the minimum bid price requirement pursuant to Nasdaq Listing Rule 5550(a)(2) (the “Minimum Bid Requirement”). On January 8, 2024, the Company effected a 1-for-20 reverse stock split of its issued and outstanding common stock (the "Reverse Stock Split"). As a result of the Reverse Stock Split, the Company regained compliance with the Nasdaq listing rules. Each of the Company’s shareholders received one new share of common stock for every 20 shares such shareholder held immediately prior to the effective time of the Reverse Stock Split. The Reverse Stock Split affected all the Company’s issued and outstanding shares of common stock equally. The par value and authorized shares of the Company's common stock was not adjusted as a result of the Reverse Stock Split. The Reverse Split also affected the Company’s outstanding common stock options and warrants, and resulted in the shares underlying such instruments being reduced and the exercise price being increased proportionately. Unless otherwise noted, all common stock shares, common stock per share data, common stock options and warrants included in these consolidated financial statements, including the exercise price of such equity instruments, as applicable, have been retrospectively adjusted to reflect the effect of the Reverse Stock Split for all periods presented.
Use of Estimates	Use of Estimates The Company’s consolidated financial statements are prepared in accordance with GAAP. The preparation of the Company’s consolidated financial statements and accompanying notes requires it to make estimates and assumptions that impact the reported amounts of assets, liabilities, revenues and expenses and the disclosure of contingent assets and liabilities. Significant estimates consist of accruals for research and development costs. Although these estimates are based on the Company’s knowledge of current events and actions it may undertake in the future, actual results may ultimately materially differ from these estimates and assumptions.
Cash and Cash Equivalents	Cash and Cash Equivalents The Company considers all highly liquid investments with maturities of three months or less when purchased to be cash equivalents. Cash and cash equivalents consist of Level 1 financial instruments in the fair value hierarchy (see Note 6 – Fair Value) and include cash in readily available checking accounts, money market accounts and commercial paper.
Short-term Investments	Short-term Investments Short-term investments consist of U.S. treasury notes and bills, certificates of deposit, commercial paper and U.S. government sponsored enterprise securities with maturities of less than one year from the balance sheet date and are debt securities considered to be Level 1 and Level 2 financial instruments in the fair value hierarchy (see Note 6 – Fair Value). The Company determines the appropriate classification of marketable securities at the time of purchase and reevaluates such designation at each balance sheet date. The Company has classified all of its marketable securities at December 31, 2023 and 2022 as “available-for-sale” pursuant to ASC 320 Investments – Debt and Equity Securities . The Company records available-for-sale securities at fair value as determined by prices for identical or similar securities, with the unrealized gains and losses included as a separate component of other accumulated comprehensive income (loss). In accordance with policy, the Company does not invest in or hold equity securities in its investment portfolio. The Company adjusts the cost of available-for-sale debt securities for amortization of premiums or accretion of discounts to maturity. The Company includes interest and dividends on securities classified as available-for-sale in interest income. Such amortization and accretion are included in interest income. The cost of securities sold is based on the specific identification method. Realized gains or losses on available-for-sale securities are determined using the specific identification method and net realized gains and losses are included in interest income. The Company records unrealized gains and losses on available-for-sale marketable securities as a component of other comprehensive loss within the statements of comprehensive loss and as a separate component of stockholders’ equity on the balance sheets. The Company elected the practical expedient to exclude the applicable accrued interest from both the fair value and amortized costs basis of available-for-sale securities for purposes of identifying and measuring an impairment. Accrued interest receivable on available-for-sale securities is recorded in short-term investments in the accompanying consolidated balance sheets. The Company’s accounting policy is to not measure an allowance for credit loss for accrued interest receivable and to write-off any uncollectible accrued interest receivable as a reversal of interest income in a timely manner, which the Company considers to be in the period in which the Company determines the accrued interest will not be collected. The Company evaluates short-term investments for other-than-temporary impairment at the balance sheet date. Factors considered in determining whether a loss is other-than temporary include how significant the decline in value is as a percentage of the original cost, the length of time and extent to which fair value has been less than the cost basis, the financial condition of the issuer, and the Company’s intent and ability to hold the investment until recovery of its amortized cost basis. The Company intends, and has the ability, to hold any investments in unrealized loss positions until their amortized cost basis has been recovered. As of December 31, 2023 and 2022, there were no impairment charges on short-term investments. The Company obtains the fair value of its available-for-sale marketable securities from a professional pricing service. The fair values of available-for-sale marketable securities are validated by comparing the fair values reported by the professional pricing service to quoted market prices or to fair values obtained from the custodian bank. The service provider values the securities using a hierarchical security pricing model that relies primarily on valuations provided by an industry-recognized valuation service or mathematical calculations. Such valuations may be based on trade prices in active markets for identical assets or liabilities (Level 1 inputs) or valuation models using inputs that are observable either directly or indirectly (Level 2 inputs), such as quoted prices for similar assets or liabilities, yield curves, credit spreads, current market and contractual prices for the underlying instruments or debt, as well as other relevant economic measures.
Deferred Compensation	Deferred Compensation Deferred compensation represents the accrual of retention bonuses for certain executives and certain other members of senior management. The retention bonuses were entered into in connection with the waiver of annual cash performance bonuses of such personnel for the year ended December 31, 2023 and a temporary reduction of the chief executive officer’s salary from April 2023 through December 2024.
Concentration of Credit Risk	Concentration of Credit Risk Financial instruments that potentially subject the Company to significant concentrations of credit risk consist primarily of cash, cash equivalents and short-term investments. The Company maintains deposits in federally insured financial institutions in excess of federally insured limits. The Company has not experienced any losses in such accounts and believes it is not exposed to significant risk on its cash balances due to the financial position of the depository institution in which those deposits are held. Additionally, the Company established guidelines regarding approved investments and maturities of investments, which are designed to maintain safety and liquidity.
Patent Costs	Patent Costs Costs related to filing and pursuing patent applications are recorded as general and administrative expense and expensed as incurred since recoverability of such expenditures is uncertain.
Research and Development Expenses and Accruals	Research and Development Expenses and Accruals Research and development expenses consist of costs incurred for the Company’s own and for sponsored and collaborative research and development activities. Research and development costs are expensed as incurred and include manufacturing process development costs, manufacturing costs, costs associated with preclinical studies and clinical trials, regulatory and medical affairs activities, quality assurance activities, salaries and benefits, including stock-based compensation, fees paid to third-party consultants, license fees and overhead. The Company has entered into various research and development contracts with research institutions, clinical research organizations, clinical manufacturing organizations and other companies. Payments for these activities are based on the terms of the individual agreements, which may differ from the pattern of costs incurred, and payments made in advance of performance are reflected in the accompanying consolidated balance sheets as prepaid and other assets or accrued liabilities. The Company records accruals for estimated costs incurred for ongoing research and development activities. When evaluating the adequacy of the accrued liabilities, which include clinical trial accruals, the Company analyzes progress of the services, including the phase or completion of events, invoices received and contracted costs. Significant judgments and estimates may be made in determining the prepaid or accrued balances at the end of any reporting period. Actual results could differ from the Company’s estimates.
Fair Value Measurements	Fair Value Measurements The accounting guidance defines fair value, establishes a consistency framework for measuring fair value and expands disclosure for each major asset and liability category measured at fair value on either a recurring basis or nonrecurring basis. Fair value is defined as an exit price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants on the measurement date. Accounting guidance establishes a three-tier fair value hierarchy that requires an entity to maximize the use of observable inputs and minimize the use of unobservable inputs when measuring fair value. These tiers are based on the source of the inputs and are as follows: Level 1: Observable inputs such as quoted prices in active markets for identical assets or liabilities. Level 2: Inputs other than quoted prices in active markets that are observable either directly or indirectly. Level 3: Unobservable inputs in which there is little or no market data, which require the reporting entity to develop its own assumptions. The Company’s financial instruments include cash, cash equivalents, short-term investments, prepaid expenses and other assets, accounts payable, accrued expenses, and accrued compensation. The carrying amounts of the Company’s current financial assets and liabilities are considered to be representative of their respective fair values because of the short-term nature of those instruments. The Company has short-term investments that are measured at fair value on a recurring basis. No transfers between levels have occurred during the periods presented (see Note 6).
Revenue Recognition	Revenue Recognition The Company generates revenue from certain grant awards or a research subaward (the “Grant Awards”) (see Note 5), which provides the Company with payments in return for certain research and development activities over a contractually defined period. Revenue from such Grant Awards is recognized in the period during which the related qualifying services are rendered and costs are incurred, provided that the applicable conditions under the Grant Awards have been met. The Grant Awards are on a best-efforts basis and do not require scientific achievement as a performance obligation. The Grant Awards are non-refundable. The costs associated with the Grant Awards are expensed as incurred and reflected as a component of research and development expense in the accompanying consolidated statements of operations. Funds received from the Grant Awards are recorded as revenue as the Company is the principal participant in the arrangement because the activities under the Grant Awards are part of the Company’s development programs. In those instances where the Company first receives consideration in advance of providing underlying services, the Company classifies such consideration as deferred revenue until (or as) the Company provides the underlying services. In those instances where the Company first provides the underlying services prior to its receipt of consideration, the Company records a grant receivable.
Stock-Based Compensation	Stock-Based Compensation Stock-based compensation expense represents the fair value of equity awards, on the grant date, recognized in the period using the Black-Scholes option pricing model. The Company recognizes expense for awards with graded vesting schedules over the requisite service period of the awards (usually the vesting period) on a straight-line basis. For equity awards for which vesting is subject to performance-based milestones, the expense is recorded over the remaining service period after the point when the achievement of the milestone is probable. The Company recognizes forfeitures for all awards as such forfeitures occur.
Income Taxes	Income Taxes The Company accounts for income taxes under the asset and liability method, which requires the recognition of deferred tax assets and liabilities for the expected future tax consequences of events that have been included in the consolidated financial statements. Under this method, deferred tax assets and liabilities are determined on the basis of the differences between the financial statements and tax basis of assets and liabilities using enacted tax rates in effect for the year in which the differences are expected to reverse. The effect of a change in tax rates on deferred tax assets and liabilities is recognized in income in the period that includes the enactment date. The Company recognizes net deferred tax assets to the extent that the Company believes these assets are more likely than not to be realized. In making such a determination, management considers all available positive and negative evidence, including future reversals of existing taxable temporary differences, projected future taxable income, tax-planning strategies, and results of recent operations. If management determines that the Company would be able to realize its deferred tax assets in the future in excess of their net recorded amount, management would make an adjustment to the deferred tax asset valuation allowance, which would reduce the provision for income taxes.
Segment Reporting	Segment Reporting Operating segments are identified as components of an enterprise about which separate discrete financial information is available for evaluation by the chief operating decision-maker in making decisions regarding resource allocation and assessing performance. The Company views its operations and manages its business in one operating segment in the United States.
Net Loss Per Share	Net Loss Per Share Basic net loss per share is computed by dividing the net loss by the weighted-average number of common shares outstanding for the period, without consideration for potentially dilutive securities and adjusted for the weighted-average number of common shares outstanding that are subject to repurchase. Diluted net loss per share is computed by dividing the net loss by the weighted-average number of shares of common stock and dilutive common stock equivalents outstanding for the period determined using the treasury-stock and if-converted methods. For all periods presented, there is no difference in the number of shares used to calculate basic and diluted shares outstanding as inclusion of the potentially dilutive securities would be antidilutive. Potentially dilutive securities not included in the calculation of diluted net loss per share, because to do so would be anti-dilutive, are as follows (in common stock equivalent shares): December 31, 2023 2022 Warrants to purchase common stock 170,521 170,521 Common stock options 548,073 425,785 Restricted stock units 18,557 50,454 737,151 646,760
Recently Accounting Pronouncements	Recently Adopted Accounting Pronouncements In June 2016, the FASB issued ASU 2016-13, Financial Instruments – Credit Losses: Measurement of Credit Losses on Financial Statements (Topic 326), which intends to improve financial reporting by requiring earlier recognition of credit losses on certain financial assets, such as available-for-sale debt securities. Topic 326 amends guidance on reporting credit losses for assets held at amortized cost basis and available-for-sale debt securities. For assets held at amortized cost basis, Topic 326 eliminates the probable initial recognition threshold in current GAAP and, instead, requires an entity to reflect its current estimate of all expected credit losses. The allowance for credit losses is a valuation account that is deducted from the amortized cost basis of the financial assets to present the net amount expected to be collected. For available-for-sale debt securities, credit losses should be measured in a manner similar to current GAAP, however Topic 326 will require that credit losses be presented as an allowance rather than as a write-down. This ASU update affects entities holding financial assets and net investment in leases that are not accounted for at fair value through net loss. This update is effective for the Company and was adopted on January 1, 2023, which did not have a material impact on its consolidated financial statements. Accounting Standards Not Yet Adopted In November 2023, the FASB issued ASU 2023-07, Segment Reporting – Improvements to Reportable Segment Disclosures (Topic 280), which intends to improve financial reporting primarily through enhanced disclosures about significant segment expenses. Topic 280 includes amendments which a) introduce a new requirement to disclose significant segment expenses regularly provided to the chief operating decision maker (CODM), b) extend  certain annual disclosures to interim periods, c) clarify single reportable segment entities must apply ASC 280 in its entirety, d) permit more than one measure of segment profit or loss to be reported under certain conditions, and e) require disclosure of the title and position of the CODM. This update is effective for all public entities beginning after December 15, 2023. The Company is currently evaluating the impact of this guidance on its consolidated financial statements. In December 2023, the FASB issued ASU 2023-09, Income Tax – Improvements to Income Tax Disclosures, which intends to improve financial reporting primarily through enhanced disclosures about significant segment expenses. The standard requires disaggregated information about a reporting entity’s effective tax rate reconciliation as well as information on income taxes paid. The standard is intended to benefit investors by providing more detailed income tax disclosures that would be useful in making capital allocation decisions. This update is effective for all public entities beginning after December 15, 2024. The Company is currently evaluating the impact of this guidance on its consolidated financial statements.

Description of Business, Basi_3

Description of Business, Basis of Presentation and Summary of Significant Accounting Policies (Tables)	12 Months Ended
	Dec. 31, 2023
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Schedule of Potentially Dilutive Securities Excluded from Calculation of Diluted Net Loss per Share Would Be Anti-dilutive	Potentially dilutive securities not included in the calculation of diluted net loss per share, because to do so would be anti-dilutive, are as follows (in common stock equivalent shares): December 31, 2023 2022 Warrants to purchase common stock 170,521 170,521 Common stock options 548,073 425,785 Restricted stock units 18,557 50,454 737,151 646,760

Balance Sheet Details (Tables)

Balance Sheet Details (Tables)	12 Months Ended
	Dec. 31, 2023
Payables and Accruals [Abstract]
Schedule of Prepaid and Other	Prepaid and other consist of the following (in thousands): December 31, December 31, 2023 2022 Research and development $ 312 $ — Clinical trials 294 2,616 Insurance 478 669 Other prepaid expenses 88 103 Related party receivable (see Note 4) 139 — Grant and other receivable 493 178 $ 1,804 $ 3,566
Summary of Accrued Liabilities	Accrued liabilities consist of the following (in thousands): December 31, December 31, 2023 2022 Research and development $ 146 $ 972 Clinical trials 2,018 868 Legal fees 134 138 Compensation 1,579 2,691 Other — 9 $ 3,877 $ 4,678

Short-term Investments (Tables)

Short-term Investments (Tables)	12 Months Ended
	Dec. 31, 2023
Investments, Debt and Equity Securities [Abstract]
Schedule of Short-term Investments and are Measured at a Fair Value on a Recurring Basis	Maturity (in years) Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Market Value As of December 31, 2023 Short term investments: U.S. Treasury debt securities 1 or less $ 23,840 $ 4 $ — $ 23,844 Commercial Paper 1 or less 2,738 — ( 1 ) 2,737 U.S. Government Agency 1 or less 977 — — 977 Total short-term investments $ 27,555 $ 4 $ ( 1 ) $ 27,558 Maturity (in years) Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Market Value As of December 31, 2022 Short term investments: U.S. Treasury debt securities 1 or less $ 21,681 $ 7 $ — $ 21,688 Commercial Paper 1 or less 2,936 — — 2,936 U.S. Government Agency 1 or less 1,956 2 — 1,958 Total short-term investments $ 26,573 $ 9 $ — $ 26,582

Commitments, Contingencies an_2

Commitments, Contingencies and Related Party Transactions (Tables)	12 Months Ended
	Dec. 31, 2023
Commitments and Contingencies Disclosure [Abstract]
Summary of Maturities of Lease Liabilities	Maturity of lease liabilities Operating 2024 $ 196 2025 150 Total lease payments 346 Less imputed interest ( 28 ) Total lease liability 318 Less current portion of lease liability ( 173 ) Lease liability, long-term $ 145

Fair Value (Tables)

Fair Value (Tables)	12 Months Ended
	Dec. 31, 2023
Fair Value Disclosures [Abstract]
Schedule of Companys Assets Measured at Fair Value on Recurring Basis	As of December 31, 2023 and December 31, 2022, the following fair value hierarchy tables presents the Company’s financial assets measured at fair value on a recurring basis (in thousands): Total Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) As of December 31, 2023 Short term investments: U.S. Treasury debt securities $ 23,844 $ 10,912 $ 12,932 $ — Commercial Paper 2,737 — 2,737 — U.S. Government Agency 977 — 977 — Total short-term investments $ 27,558 $ 10,912 $ 16,646 $ — Total Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) As of December 31, 2022 Short term investments: U.S. Treasury debt securities $ 21,688 $ 21,688 $ — $ — Commercial Paper 2,936 — 2,936 — U.S. Government Agency 1,958 — 1,958 — Total short-term investments $ 26,582 $ 21,688 $ 4,894 $ —

Stockholders' Equity (Tables)

Stockholders' Equity (Tables)	12 Months Ended
	Dec. 31, 2023
Summary Of Warrant Activity And Changes In Warrants Outstanding	A summary of warrant activity and changes in warrants outstanding is presented below: Number of Weighted-Average Weighted-Average Remaining Contractual Term Balance Outstanding - December 31, 2021 211,746 $ 210.00 3.31 Expired ( 41,225 ) 772.80 — Balance Outstanding - December 31, 2022 170,521 74.00 2.94 Issued / Exercised / Forfeited / Expired — — — Balance Outstanding - December 31, 2023 170,521 $ 74.00 1.94
Summary of Stock Option Activity	A summary of the Company’s stock option activity under the 2015 Plan, 2019 Plan and Inducement Plan is as follows: Number of Weighted- Weighted- Aggregate Outstanding at December 31, 2022 425,766 $ 83.25 Granted 173,794 $ 16.49 Cancelled ( 51,487 ) $ 69.09 Outstanding at December 31, 2023 548,073 $ 56.51 7.4 $ 155,648 Options vested and expected to vest at December 31, 2023 548,073 $ 56.51 7.4 $ 155,648 Vested and exercisable at December 31, 2023 279,184 $ 74.09 7.1 $ 68,418
Summary of Restricted Stock Unit Activity	Number of Restricted Stock Units Weighted-Average Remaining Contractual Term (in years) Weighted-Average Grant Date Fair Value Nonvested at December 31, 2022 50,438 $ 32.80 Granted — Vested ( 30,537 ) $ 35.56 Forfeited/ Repurchased ( 1,344 ) $ 32.16 Nonvested at December 31, 2023 18,557 0.1 $ 28.32 Units expected to vest as of December 31, 2023 18,557 0.1 $ 28.32 The weighted average grant date fair value per share of RSU grants for the years ended December 31, 2023 and 2022 was none and $ 33.01 per share, respectively. The total fair value of shares vested during the year ended December 31, 2023 was $ 0.4 million. The total fair value of shares vested during the year ended December 31, 2022 was nominal.
Schedule of Assumptions Used to Determine Fair Value	The weighted-average assumptions used in the Black-Scholes option pricing model to determine the fair value of stock option grants were as follows: Years Ended 2023 2022 Risk-free interest rate 4.1 % 2.2 % Expected volatility 100.6 % 100.5 % Expected term (in years) 6.0 6.1 Expected dividend yield — % — %
Summary of Share-Based Compensation Expense	Stock-based compensation expense recognized for all equity awards has been reported in the statements of operations as follows (in thousands): Years Ended 2023 2022 Research and development $ 4,064 $ 4,055 General and administrative 3,436 3,376 $ 7,500 $ 7,431
Common Stock Reserved for Future Issuance	Common stock reserved for future issuance is as follows: December 31, 2023 2022 Common stock warrants 170,521 170,521 Common stock options outstanding 548,073 425,785 Restricted stock unit awards unvested and outstanding 18,557 50,454 Common stock available for issuance under Inducement Plan and 2019 Plan 94,909 61,500 832,060 708,260

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2023
Income Tax Disclosure [Abstract]
Summary of Reconciliation of Effective Tax Rate and Federal Statutory Tax Rate	A reconciliation of the Company’s effective tax rate and federal statutory tax rate is as follows (in thousands): Years Ended 2023 2022 Federal income taxes $ ( 8,290 ) $ ( 9,276 ) State income taxes, net of federal benefit ( 58 ) ( 2,820 ) Permanent items 8 3 Stock based compensation 1,172 831 Research and development credit carryforwards ( 2,910 ) ( 4,747 ) State rate change 1,222 — Other, net 196 ( 48 ) Change in valuation allowance 8,660 16,057 Provision for income taxes $ — $ —
Summary of Significant Components of Net Deferred Tax Assets	Significant components of the Company’s net deferred tax assets are as follows (in thousands): December 31, 2023 2022 Deferred tax assets: Net operating loss carryforwards $ 29,997 $ 27,889 Research and development credit carryforwards 10,958 7,804 Accrued expenses 676 860 Capitalized research and development costs 22,501 19,153 Stock based compensation 2,406 2,188 Other, net 90 29 Total deferred tax assets 66,628 57,923 Valuation allowance ( 66,561 ) ( 57,899 ) Deferred tax assets, net 67 24 Deferred tax liabilities: Right of use asset ( 67 ) ( 24 ) Total deferred tax liabilities ( 67 ) ( 24 ) Net deferred tax assets $ — $ —

Description of Business, Basi_4

Description of Business, Basis of Presentation and Summary of Significant Accounting Policies - Additional Information (Details)		1 Months Ended	12 Months Ended
	Jan. 08, 2024	Dec. 31, 2023 USD ($) shares	Dec. 31, 2023 USD ($) Segment shares	Dec. 31, 2022 USD ($) shares	Apr. 04, 2023 $ / shares
Description Of Business Basis Of Presentation And Summary Of Significant Accounting Policies [Line Items]
Accumulated deficit		$ (197,779,000)	$ (197,779,000)	$ (158,300,000)
Cash, cash equivalents, and short-term investments		$ 34,300,000	34,300,000
Common stock transaction price per share | $ / shares					$ 1
Impairment charges on short-term investments			$ 0	$ 0
Number of operating segments | Segment			1
Common Stock | ATM Program
Description Of Business Basis Of Presentation And Summary Of Significant Accounting Policies [Line Items]
Common stock shares issued | shares			38,800,000
Number of shares sold | shares		457,342	55,274	402,068
Net proceeds from sale of shares		$ 10,800,000	$ 1,200,000	$ 9,600,000
Subsequent Event
Description Of Business Basis Of Presentation And Summary Of Significant Accounting Policies [Line Items]
Reverse Stock Split description	1-for-20

Description of Business, Basi_5

Description of Business, Basis of Presentation and Summary of Significant Accounting Policies - Schedule of Potentially Dilutive Securities Excluded from Calculation of Diluted Net Loss per Share Would Be Anti-dilutive (Detail) - shares	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Potentially dilutive securities	737,151	646,760
Warrants to purchase common stock
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Potentially dilutive securities	170,521	170,521
Common Stock Options
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Potentially dilutive securities	548,073	425,785
Restricted Stock Unit
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Potentially dilutive securities	18,557	50,454

Balance Sheet Details - Prepaid

Balance Sheet Details - Prepaid and Other (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Related Party Transaction [Line Items]
Research and development	$ 312	$ 0
Clinical trials	294	2,616
Insurance	478	669
Other prepaid expenses	88	103
Grant and other receivable	493	178
Prepaid and other expense total	1,804	3,566
Related Party [Member]
Related Party Transaction [Line Items]
Related party receivable	$ 139	$ 0

Balance Sheet Details - Accrued

Balance Sheet Details - Accrued Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Payables and Accruals [Abstract]
Research and development	$ 146	$ 972
Clinical trials	2,018	868
Legal fees	134	138
Compensation	1,579	2,691
Other	0	9
Total accrued liabilities	$ 3,877	$ 4,678

Short-term Investments - Schedu

Short-term Investments - Schedule of Short-term Investments and are Measured at a Fair Value on a Recurring Basis (Details) - Short term investments - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Debt Securities, Available-for-Sale [Line Items]
Amortized Cost	$ 27,555	$ 26,573
Gross Unrealized Gains	4	9
Gross Unrealized Losses	(1)	0
Available-for-sale debt securities	27,558	26,582
U.S. Treasury debt securities
Debt Securities, Available-for-Sale [Line Items]
Amortized Cost	23,840	21,681
Gross Unrealized Gains	4	7
Gross Unrealized Losses	0	0
Available-for-sale debt securities	$ 23,844	$ 21,688
U.S. Treasury debt securities | Maximum
Debt Securities, Available-for-Sale [Line Items]
Maturity (in years)	1 year	1 year
Commercial Paper
Debt Securities, Available-for-Sale [Line Items]
Amortized Cost	$ 2,738	$ 2,936
Gross Unrealized Gains	0
Gross Unrealized Losses	(1)	0
Available-for-sale debt securities	$ 2,737	$ 2,936
Commercial Paper | Maximum
Debt Securities, Available-for-Sale [Line Items]
Maturity (in years)	1 year	1 year
U.S. Government Agency
Debt Securities, Available-for-Sale [Line Items]
Amortized Cost	$ 977	$ 1,956
Gross Unrealized Gains	0	2
Gross Unrealized Losses	0	0
Available-for-sale debt securities	$ 977	$ 1,958
U.S. Government Agency | Maximum
Debt Securities, Available-for-Sale [Line Items]
Maturity (in years)	1 year	1 year

Short-term Investments - Additi

Short-term Investments - Additional Information (Details) - USD ($)	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Short-Term Investments
Debt Securities, Available-for-Sale, Accrued Interest, after Allowance for Credit Loss, Statement of Financial Position [Extensible Enumeration]	Assets	Assets
Marketable securities credit losses	$ 0	$ 0
Unrealized gain (loss) on available-for-sale securities	(6,000)	9,000
Accrued interest receivable on available-for-sale securities	15,000	116,000
Debt securities, available-for-sale, accrued interest writeoff	$ 0	$ 0

Commitments, Contingencies an_3

Commitments, Contingencies and Related Party Transactions - Additional Information (Details) - USD ($) $ in Thousands	1 Months Ended		12 Months Ended
	May 31, 2023	Apr. 30, 2022	Dec. 31, 2023	Dec. 31, 2022
Commitments And Contingencies [Line Items]
Operating lease liability			$ 318
Shanghai Pharmaceutical (USA) Inc.
Commitments And Contingencies [Line Items]
Proceeds from collaborators			500
Related party receivable			100	$ 0
San Diego, California | Office Space
Commitments And Contingencies [Line Items]
Rent expense			$ 200	$ 200
Lease expiration date	Sep. 30, 2025	Jul. 31, 2023
Annual base rent	$ 145,000
Lease discount rate			10%
Operating lease liability			$ 300
Weighted average remaining lease term			1 year 9 months 18 days	7 months 6 days

Commitments, Contingencies an_4

Commitments, Contingencies and Related Party Transactions - Summary of Maturities of Lease Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Commitments and Contingencies Disclosure [Abstract]
2024	$ 196
2025	150
Total lease payments	346
Less imputed interest	(28)
Total lease liability	318
Less current portion of lease liability	(173)	$ (87)
Lease liability, long-term	$ 145	$ 0

License, Collaboration, Grant_2

License, Collaboration, Grants, Research Subaward Agreement and CVR Agreements (Details) - USD ($)		1 Months Ended			12 Months Ended
	Nov. 01, 2021	Jan. 31, 2022	Aug. 31, 2017	May 31, 2016	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2017
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Patent costs as general and administrative expense					$ 12,746,000	$ 13,457,000
Grant revenue					785,000	1,490,000
The National Institute of Health (“NIH”) Grant Awards
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Grants awarded to researchers					4,000,000
Grant revenue					400,000	1,200,000
Payable to subawardees					1,000,000
Award payments received					800,000	1,100,000
Unbilled grant receivable					$ 500,000	100,000
Regents of the University of California
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Written notice of termination, period					60 days
Research and development expense					$ 25,000	25,000
Upfront license fees paid				$ 500,000
Common stock shares issued				5,355
Annual license maintenance fees							$ 25,000
Worldwide sales milestones based on achievement of tiered revenue levels				$ 75,000,000
Patent costs as general and administrative expense					100,000	100,000
University of California San Diego School of Medicine | The California Institute for Regenerative Medicine ("CIRM") Award
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Grants awarded to researchers			$ 18,300,000
Development milestones to be received under research subaward agreements throughout award project period			$ 14,500,000
Research Agreement 2022 | Regents of the University of California | The National Institute of Health (“NIH”) Grant Awards
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Research agreement term		4 years
Research amount received		$ 1,600,000
Research amount payable quarterly		125,000
Other research and development expense					500,000	500,000
Research Agreement 2023 | Regents of the University of California | The National Institute of Health (“NIH”) Grant Awards
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Research amount payable quarterly		131,250
Research Agreement 2024 | Regents of the University of California | The National Institute of Health (“NIH”) Grant Awards
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Research amount payable quarterly		137,813
Research Agreement 2025 | Regents of the University of California | The National Institute of Health (“NIH”) Grant Awards
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Research amount payable quarterly		$ 137,813
License Agreement | University of Tennessee Research Foundation
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Research and development expense					$ 200,000	$ 300,000
CVR Agreement
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Percentage of net sales	5%
Period from closing during which payment of percentage of net proceeds would be payable under the CVR	15 years
Period from closing during which the grant, sale or transfer of rights to the Company's SARD or SARM technology could trigger a payment under the CVR Agreement	10 years
Maximum | Regents of the University of California
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Potential regulatory milestone payments				24,500,000
Minimum [Member] | Regents of the University of California
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Potential regulatory milestone payments				20,100,000
Advance licensed assets				$ 1,000,000

Fair Value - Schedule of Compan

Fair Value - Schedule of Companys Assets Measured at Fair Value on Recurring Basis (Details) - Fair Value Measurements Recurring - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total short-term investments	$ 27,558	$ 26,582
U.S. Government Agency
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total short-term investments	977	1,958
U.S. Treasury debt securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total short-term investments	23,844	21,688
Commercial Paper
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total short-term investments	2,737	2,936
Quoted Prices in Active Markets for Identical Assets (Level 1)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total short-term investments	10,912	21,688
Quoted Prices in Active Markets for Identical Assets (Level 1) | U.S. Government Agency
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total short-term investments	0	0
Quoted Prices in Active Markets for Identical Assets (Level 1) | U.S. Treasury debt securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total short-term investments	10,912	21,688
Quoted Prices in Active Markets for Identical Assets (Level 1) | Commercial Paper
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total short-term investments	0	0
Significant Other Observable Inputs (Level 2)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total short-term investments	16,646	4,894
Significant Other Observable Inputs (Level 2) | U.S. Government Agency
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total short-term investments	977	1,958
Significant Other Observable Inputs (Level 2) | U.S. Treasury debt securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total short-term investments	12,932	0
Significant Other Observable Inputs (Level 2) | Commercial Paper
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total short-term investments	2,737	2,936
Significant Unobservable Inputs (Level 3)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total short-term investments	0	0
Significant Unobservable Inputs (Level 3) | U.S. Government Agency
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total short-term investments	0	0
Significant Unobservable Inputs (Level 3) | U.S. Treasury debt securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total short-term investments	0	0
Significant Unobservable Inputs (Level 3) | Commercial Paper
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total short-term investments	$ 0	$ 0

Stockholders' Equity - ATM Prog

Stockholders' Equity - ATM Program (Details) - ATM Program - Common Stock - USD ($) $ in Millions	1 Months Ended		12 Months Ended
	Dec. 31, 2023	Dec. 31, 2021	Dec. 31, 2023	Dec. 31, 2022
Subsidiary, Sale of Stock [Line Items]
Number of shares sold	457,342		55,274	402,068
Net proceeds from sale of shares	$ 10.8		$ 1.2	$ 9.6
Aggregate offering price		$ 50

Stockholders' Equity - Summary

Stockholders' Equity - Summary Of Warrant Activity And Changes In Warrants Outstanding (Details) - $ / shares shares in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Equity [Abstract]
Options outstanding, Number of Warrant	170,521	211,746
Number of Shares Underlying Warrants Issued	0
Number of Shares Underlying Warrants Exercised	0
Number of Shares Underlying Warrants Forfeited	0
Number of Shares Underlying Warrants Expired	0	(41,225)
Options outstanding, Number of Warrant	170,521	170,521	211,746
Weighted-Average Exercise Price	$ 74	$ 210
Warrant Exercised Price Per Share Issued	0
Warrant Exercised Price Per Share Exercised	0
Warrant Exercised Price Per Share Forfeited	0
Warrant Exercised Price Per Share Expired	0	772.8
Weighted-Average Exercise Price	$ 74	$ 74	$ 210
Weighted-Average Remaining Contractual Term	1 year 11 months 8 days	2 years 11 months 8 days	3 years 3 months 21 days

Stockholders' Equity - Equity I

Stockholders' Equity - Equity Incentive Plans (Details) - USD ($) $ / shares in Units, $ in Thousands	1 Months Ended		12 Months Ended
	Oct. 31, 2023	Jul. 31, 2015	Dec. 31, 2023	Dec. 31, 2022	May 25, 2021
Class Of Stock [Line Items]
Percentage of annual increase in shares reserved for issuance			5%
Number of common stock shares provided for issuance of stock awards to its employees			832,060	708,260
Stock-based compensation expense			$ 7,500	$ 7,431
Fair value of RSUs vested			$ 400
Repriced Stock Options
Class Of Stock [Line Items]
Stock-based compensation expense	$ 400
Incremental fair value of unvested options	$ 400
Restricted Stock Unit
Class Of Stock [Line Items]
Weighted average grant date fair value per share of option grants			$ 0	$ 33.01
2019 incentive award plan
Class Of Stock [Line Items]
Shares of common stock reserved for issuance			97,708
2019 incentive award plan and inducement plan
Class Of Stock [Line Items]
Number of common stock shares provided for issuance of stock awards to its employees					140,000
2015 plan
Class Of Stock [Line Items]
Options expiration term		10 years
Options vesting period		4 years
2019 and 2015 plan
Class Of Stock [Line Items]
Weighted average grant date fair value per share of option grants			$ 13.33	$ 25.81
2019 plan
Class Of Stock [Line Items]
Options expiration term		10 years
Options vesting period		4 years

Stockholders' Equity - Summar_2

Stockholders' Equity - Summary of Stock Option Activity (Details) - Equity incentive plan $ / shares in Units, shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2023 USD ($) $ / shares shares
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of options, beginning balance | shares	425,766
Number of options, granted | shares	173,794
Number of options, cancelled | shares	(51,487)
Number of options, ending balance | shares	548,073
Number of options vested and expected to vest | shares	548,073
Number of options, vested and exercisable | shares	279,184
Weighted average exercise price, beginning balance | $ / shares	$ 83.25
Weighted average exercise price, granted | $ / shares	16.49
Weighted average exercise price, cancelled | $ / shares	69.09
Weighted average exercise price, exercised | $ / shares	56.51
Weighted average exercise price, options vested and expected to vest | $ / shares	56.51
Weighted average exercise price, vested and exercisable | $ / shares	$ 74.09
Weighted average contractual term outstanding, ending balance	7 years 4 months 24 days
Weighted-average remaining contractual term, Options vested and expected to vest	7 years 4 months 24 days
Remaining weighted-average period, vested and exercisable	7 years 1 month 6 days
Options outstanding, Aggregate Intrinsic Value | $	$ 155,648
Aggregate intrinsic value, options vested and expected to vest | $	155,648
Vested and exercisable, Aggregate intrinsic value | $	$ 68,418

Stockholders' Equity - Summar_3

Stockholders' Equity - Summary of Restricted Stock Unit Activity (Details) - Restricted Stock Unit shares in Thousands	12 Months Ended
	Dec. 31, 2023 $ / shares shares
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Number of restricted stock units, Beginning balance	50,438
Number of restricted stock units, Granted	0
Number of restricted stock units, Vested	(30,537)
Number of restricted stock units, Forfeited/Repurchased	(1,344)
Number of restricted stock units, Ending balance	18,557
Number of restricted units expected to vest	18,557
Weighted-average remaining contractual term nonvested	1 month 6 days
Weighted-average remaining contractual term, Options vested and expected to vest	1 month 6 days
Weighted-average grant date fair value nonvested | $ / shares	$ 32.8
Weighted-average grant date fair value, vested | $ / shares	35.56
Weighted average exercise price, Forfeited/ Repurchased | $ / shares	32.16
Weighted-average grant date fair value nonvested | $ / shares	28.32
Weighted average exercise price, options vested and expected to vest | $ / shares	$ 28.32

Stockholders' Equity - Schedule

Stockholders' Equity - Schedule of Assumptions Used to Estimate Fair Value of Stock Option Grants (Details)	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Share-Based Payment Arrangement [Abstract]
Risk-free interest rate	4.10%	2.20%
Expected volatility	100.60%	100.50%
Expected term (in years)	6 years	6 years 1 month 6 days

Stockholders' Equity - Share-Ba

Stockholders' Equity - Share-Based Compensation Expense (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Stock-based compensation expense	$ 7,500	$ 7,431
Research and development
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Stock-based compensation expense	4,064	4,055
General and administrative
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Stock-based compensation expense	$ 3,436	$ 3,376

Stockholders' Equity - Stock-Ba

Stockholders' Equity - Stock-Based Compensation Expense (Details) $ in Millions	12 Months Ended
	Dec. 31, 2023 USD ($)
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Unrecognized compensation cost related to non-vested stock option	$ 7.7
Remaining weighted-average period	1 year 10 months 24 days

Stockholders' Equity - Common S

Stockholders' Equity - Common Stock Reserved for Future Issuance (Details) - shares	Dec. 31, 2023	Dec. 31, 2022
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Common stock warrants	170,521	170,521
Common stock options outstanding	548,073	425,785
Restricted stock unit awards unvested and outstanding	18,557	50,454
Common stock available for issuance under the Inducement Plan and 2019 Plan	832,060	708,260
Inducement Plan and 2019 Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Common stock available for issuance under the Inducement Plan and 2019 Plan	94,909	61,500

Income Taxes - Summary of Recon

Income Taxes - Summary of Reconciliation of Effective Tax Rate and Federal Statutory Tax Rate (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Income Tax Disclosure [Abstract]
Federal income taxes	$ (8,290)	$ (9,276)
State income taxes, net of federal benefit	(58)	(2,820)
Permanent items	8	3
Stock based compensation	1,172	831
Research and development credit carryforwards	(2,910)	(4,747)
State rate change	1,222	0
Other, net	196	(48)
Change in valuation allowance	8,660	16,057
Provision for income taxes	$ 0	$ 0

Income Taxes - Summary of Signi

Income Taxes - Summary of Significant Components of Net Deferred Tax Assets (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Deferred tax assets:
Net operating loss carryforwards	$ 29,997	$ 27,889
Research and development credit carryforwards	10,958	7,804
Accrued expenses	676	860
Capitalized research and development costs	22,501	19,153
Stock based compensation	2,406	2,188
Other, net	90	29
Total deferred tax assets	66,628	57,923
Valuation allowance	(66,561)	(57,899)
Deferred tax assets, net	67	24
Deferred tax liabilities:
Right of use asset	(67)	(24)
Total deferred tax liabilities	(67)	(24)
Assets [Member]
Deferred tax liabilities:
Net deferred tax assets	$ 0	$ 0

Income Taxes - Additional Infor

Income Taxes - Additional Information (Details) - USD ($)	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Income Taxes [Line Items]
Deferred tax assets, fully offset by valuation allowance	$ 66,561,000	$ 57,899,000
Change In Valuation Allowance	8,700,000	16,100,000
Research and development credit carryforward	10,958,000	7,804,000
Unrecognized Tax Benefits	0	$ 0
Interest and penalties	0
Federal
Income Taxes [Line Items]
Net operating loss carryforwards	119,500,000
Operating loss carryforwards non expire portion	$ 93,200,000
Operating loss carryforwards expiration year	2033
Research and development credit carryforward	$ 4,300,000
Research and development credit carryforward expiration year	2034
State
Income Taxes [Line Items]
Net operating loss carryforwards	$ 70,400,000
Operating loss carryforwards non expire portion	$ 0
Operating loss carryforwards expiration year	2029
Research and development credit carryforward	$ 2,900,000