0001193125-26-211898 | 10-Q | XBRL Viewer

Significant Accounting Policies (Policies)

3 Months Ended

Mar. 31, 2026

The unaudited condensed consolidated financial statements have been prepared in conformity with U.S. generally accepted accounting principles, or U.S. GAAP. The unaudited condensed consolidated financial statements include the operations of LeonaBio, Inc., and its wholly owned Australian subsidiary. All intercompany balances and transactions have been eliminated upon consolidation.

The Company effected a reverse stock split on September 17, 2025 of its outstanding shares of common stock at a ratio of 1-for-10 pursuant to a Certificate of Amendment to the Company's Certificate of Incorporation filed with the Secretary of State of the State of Delaware, or the reverse stock split. The reverse stock split was reflected on the Nasdaq Capital Market beginning with the opening of trading on September 18, 2025. The reverse stock split did not change the par value of the Company's common stock. The reverse stock split reduced the total number of authorized number of shares of the Company's common stock from 900,000,000 to 90,000,000 and the total number of authorized shares of the Company’s capital stock from 1,000,000,000 to

190,000,000. On March 18, 2026, the Company held a special meeting of stockholders in which the stockholders approved the amendment of the Company's amended and restated certificate of incorporation to increase the number of authorized shares to 500,000,000, of which 400,000,000 shares are Common Stock, $0.0001 par value share, and 100,000,000 shares are Preferred Stock, $0.0001 par value per share. All share amounts and per share amounts disclosed in this Quarterly Report on Form 10-Q have been restated to reflect the reverse stock split on a retroactive basis in all periods presented.

Unaudited Interim Condensed Financial Statements

Unaudited Interim Condensed Consolidated Financial Statements

The accompanying condensed consolidated balance sheet as of March 31, 2026, and condensed consolidated statements of operations and comprehensive loss, cash flows, and stockholders’ equity for the three months ended March 31, 2026 and 2025, are unaudited. The balance sheet as of December 31, 2025 was derived from the audited consolidated financial statements as of and for the year ended December 31, 2025. The unaudited interim condensed consolidated financial statements have been prepared on a basis consistent with the audited annual financial statements as of and for the year ended December 31, 2025, and, in the opinion of management, reflect all adjustments, consisting solely of normal recurring adjustments, necessary for the fair presentation of the Company’s financial position as of March 31, 2026, and the unaudited condensed consolidated results of its operations and its cash flows for the three months ended March 31, 2026 and 2025. The financial data and other information disclosed in these notes related to the three months ended March 31, 2026 and 2025 are also unaudited. The unaudited condensed consolidated results of operations for the three months ended March 31, 2026 are not necessarily indicative of the results to be expected for the full year ending December 31, 2026 or any other period. These unaudited interim condensed consolidated financial statements should be read in conjunction with the Company’s audited consolidated financial statements as of and for the year ended December 31, 2025 included in its Annual Report on Form 10-K filed with the Securities and Exchange Commission, or SEC, on March 31, 2026.

Fair Value Measurements

The Company has certain assets and liabilities that are measured at fair value on a recurring basis according to a fair value hierarchy that prioritizes the inputs, assumptions and valuation techniques used to measure fair value. The three levels of the fair value hierarchy are:

Level 1—Unadjusted quoted prices in active markets that are accessible at the measurement date for identical, unrestricted assets or liabilities.

Level 2—Quoted prices in markets that are not active or financial instruments for which all significant inputs are observable, either directly or indirectly.

Level 3—Inputs are generally unobservable and reflect management’s estimates of assumptions that market participants would use in pricing the asset or liability. The fair values are determined using model-based techniques, including probability-based simulation methodologies.

The determination of a financial instrument’s level within the fair value hierarchy is based on an assessment of the lowest level of any input that is significant to the fair value measurement. The Company considers observable data to be market data, which is readily available, regularly distributed or updated, reliable and verifiable, not proprietary, and provided by independent sources that are actively involved in the relevant market.

The carrying amounts of certain financial instruments, including cash, cash equivalents, restricted cash, investments, accounts payable and accrued expenses approximate their fair values due to the short-term nature of those amounts.

Restricted Cash

Cash, cash equivalents and restricted cash

Cash and cash equivalents have a maturity date of less than three months to maturity when acquired by the Company. Restricted cash consists of collateral pledged in connection with the Company's corporate credit cards. The table below reconciles the balances of cash and cash equivalents and restricted cash reported on the consolidated balance sheets to the balances of cash, cash equivalents and restricted cash reported on the consolidated statements of cash flows.


	March 31,		December 31,
	2026		2025
Cash and cash equivalents	$	32,833	$	69,276
Restricted cash		631		631
Cash, cash equivalents and restricted cash	$	33,464	$	69,907

Short-term Investments

The Company generally invests its excess cash in investment grade short- to intermediate-term fixed income securities. Such investments are included in cash and cash equivalents, and short-term investments on the consolidated balance sheets, classified as available-for-sale, and reported at fair value with unrealized gains and losses included in accumulated other comprehensive income (loss). Amortization and accretion are included in other income, net. Realized gains and losses on the sale of these securities are recognized in other income, net.

The Company periodically evaluates whether declines in fair values of its investments below their book value are due to expected credit losses, as well as the Company's ability and intent to hold the investment until a forecasted recovery occurs. Expected credit losses are recorded as an allowance through other income, net.

Warrants

The Company accounts for warrants as either equity-classified or liability-classified instruments based on an assessment of the warrant’s specific terms and applicable authoritative guidance in Accounting Standards Codification ("ASC") 480 and ASC 815. This assessment is conducted at the time the warrants are issued and reassessed as of each subsequent reporting period while the warrants are outstanding.

For warrants that meet all criteria for equity classification, the warrants are required to be recorded at their initial fair value at the time of issuance, as a component of additional paid-in capital, on the consolidated statement of stockholders’ equity. For warrants that do not meet all the criteria for equity classification, the warrants are required to be recorded at their initial fair value on the date of issuance, and on each balance sheet date thereafter until such time that the warrants are exercised, expire or otherwise qualify for equity classification. Changes in the estimated fair value of the warrants are recorded as a non-cash gain or loss on the consolidated statements of operations and comprehensive loss.

If the Company determines that a warrant subsequently meets the criteria for equity classification, the warrant is remeasured at fair value immediately prior to reclassification, with the resulting change in fair value recorded as a non-cash gain or loss on the consolidated statements of operations and comprehensive loss. The warrant is then reclassified from a liability to additional paid‑in capital at its fair value on the reclassification date and is not subsequently remeasured.

Use of Estimates

The preparation of financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and the disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of expenses during the reporting period. Estimates include those used for fair value of assets and liabilities, fair value of warrant liabilities, fair value of milestone liability, accrued liabilities, valuation allowance for deferred tax assets, and stock-based compensation. Management evaluates related assumptions on an ongoing basis using historical experience and other factors and adjusts those estimates and assumptions when facts and circumstances dictate. Actual results could differ from those estimates.

Research and Development Expenses

Research and development expenses consist primarily of direct and indirect costs incurred for research activities, including development of the pipeline from the Company’s drug discovery efforts and the development of its drug candidates. Direct costs include laboratory materials and supplies, contracted research and manufacturing, clinical trial costs, consulting fees, and other expenses incurred to sustain the Company’s research and development program. Indirect costs include personnel-related expenses, consisting of employee salaries, related benefits, and stock-based compensation expense for employees engaged in research and development activities, and facilities and other expenses consisting of direct and allocated expenses for rent and depreciation and lab consumables.

Research and development costs are expensed as incurred. In-licensing fees and other costs to acquire technologies used in research and development that have not yet received regulatory approval and that are not expected to have an alternative future use are expensed when incurred. Non-refundable advance payments for goods and services that will be used over time for research and development are capitalized and recognized as goods are delivered or as the related services are performed. The Company estimates the period over which such services will be performed and the level of effort to be expended in each period. If actual timing of performance or the level of effort varies from the estimate, the Company adjusts the amounts recorded accordingly. The Company has not experienced any material differences between accrued or prepaid costs and actual costs since inception.

Contingent consideration arrangements

In connection with certain asset acquisitions, the Company may agree to make certain milestone payments to the owners of licensed technology acquired upon the achievement of certain development, clinical and commercial milestones. These obligations may be settled in cash or in the Company’s equity shares.

Contingent consideration payable in cash is first evaluated under ASC 815 to determine whether the arrangement meets the definition of a derivative. If the contingent payment arrangement does not qualify as a derivative under ASC 815, the Company applies the guidance in ASC 450, Contingencies. Under this model, contingent consideration is not included in the cost of the assets acquired until the contingency is resolved. A liability is recognized only when the contingent payment is probable and reasonably estimable.

Contingent consideration that is required or may be settled in the Company’s equity shares is evaluated under ASC 480, Distinguishing Liabilities from Equity, to determine proper classification. Obligations that require or may require the Company to issue a variable number of shares with a monetary value that is fixed, indexed to something other than the Company’s own shares, or based on an obligation to repurchase shares are classified as liabilities under ASC 480.

Contingent consideration arrangements classified as liabilities under ASC 480 are carried at fair value. The Company estimates the fair value by applying a probability-based model that utilizes inputs primarily based upon the achievement and related timing of certain development, clinical and commercial milestones that were unobservable in the market. The estimated fair value of contingent consideration liabilities, initially measured and recorded on the acquisition date, are considered to be a Level 3 fair value measurement and are reviewed quarterly, or whenever events or circumstances occur that indicate a change in fair value. The contingent consideration liabilities are recorded at fair value at the end of each reporting period with changes in estimated fair values recorded in other income (expense) in the consolidated statements of operations and other comprehensive loss.

Significant changes in any of the probabilities of success or in the probabilities as to the periods in which milestones would be achieved could result in a significantly higher or lower fair value measurement. The Company will continue to adjust the liabilities for changes in fair value until the earlier of the achievement or expiration of the obligations.

General and Administrative Expenses

General and administrative expenses consist primarily of personnel-related costs, consisting of employee salaries, related benefits, and stock-based compensation expense for employees in the executive, legal, finance and accounting, human resources, and other administrative functions. General and administrative expenses also include third-party costs such as legal costs, insurance costs, accounting, auditing and tax related fees, consulting fees and facilities and other expenses not otherwise included as research and development expenses. General and administrative costs are expensed as incurred.

Leases

The Company adopted Accounting Standards Codification, ("ASC"), Topic 842 – Leases effective January 1, 2020. The Company determines if an arrangement contains a lease at inception. The Company performed an evaluation of contracts in accordance with ASC 842 and has determined it has an operating lease agreement for the laboratory and office facilities that the Company occupies. Operating lease right-of-use ("ROU") assets and operating lease liabilities are recognized at the date the underlying asset becomes available for the Company’s use. Operating lease liabilities are based on the present value of the future minimum lease payments over the lease term. ROU assets are measured at the amount of the lease liability, adjusted for any initial direct costs incurred and any lease payments made at or before the lease commencement date, less lease incentives received. As the Company’s leases generally do not provide an implicit interest rate, the present value of the future minimum lease payments is determined using the Company’s incremental borrowing rate. This rate is an estimate of the collateralized borrowing rate the Company would incur on its future lease payments over a similar term and is based on the information available to the Company at the lease commencement date.

The Company’s leases contain options to extend the leases; lease terms are adjusted for these options only when it is reasonably certain the Company will exercise these options. The Company’s lease agreements do not contain residual value guarantees or covenants.

The Company has made a policy election regarding its real estate leases not to separate non-lease components from lease components, to the extent they are fixed. Non-lease components that are not fixed are expensed as incurred as variable lease expense. The Company’s leases include variable non-lease components, such as common-area maintenance costs. The Company has elected not to record on the balance sheet a lease that has a lease term of 12 months or less and does not contain a purchase option that the Company is reasonably certain to exercise. The Company accounts for leases with initial terms of 12 months or less as operating expenses on a straight-line basis over the lease term.

Lease expense is recognized within operating expenses on a straight-line basis over the terms of the leases. Incentives granted under the Company’s facilities lease, including rent holidays, are recognized as adjustments to lease expense on a straight-line basis over the term of the lease.

Stock-based Compensation

The Company measures compensation expense for all stock-based payments to employees, officers and directors based on the estimated fair value of the award at the grant date. For stock options, the Company estimates the grant date fair value of each option award using the Black-Scholes option-pricing model. The grant date fair value of restricted stock units ("RSUs") is based upon the fair market value of the Company’s common stock based on its closing price as reported on the date of grant on the Nasdaq Capital Market. Compensation expense is recognized over the requisite service period on a straight-line basis. Forfeitures are recognized as they occur.

The Company records compensation expense for stock option and RSU grants subject to performance-based milestone vesting over the remaining implicit service period when management determines that achievement of the milestone is probable. Management evaluates when the achievement of a performance-based milestone is probable based on the relative satisfaction of the performance conditions as of the reporting date.

Net Loss Per Share Attributable to Common Stockholders

Basic net loss per share attributable to common stockholders is calculated by dividing the net loss attributable to common stockholders by the weighted-average number of shares of common stock outstanding for the period, without consideration of potentially dilutive securities. Diluted net loss per share attributable to common stockholders is the same as basic net loss per share attributable to common stockholders since the effect of potentially dilutive securities is anti-dilutive given the net loss of the Company. Basic and diluted net loss per share also includes contingently issuable shares once all conditions are satisfied.

Description of Business - Additional Information (Details) - USD ($) $ in Thousands	1 Months Ended		3 Months Ended
	Dec. 31, 2025	Jan. 31, 2023	Mar. 31, 2026	Mar. 31, 2025
Description Of Business [Line Items]
Entity incorporation, date of Incorporation			Mar. 31, 2011
Entity reincorporation, date of reincorporation			Oct. 27, 2015
Net cash proceeds from issuance of convertible preferred stock, common stock warrants, and convertible notes			$ 489,800
Proceeds from Issuance of Private Placement	$ 90,000
Cash, cash equivalents, and investments			67,700
Net loss			(32,948)	$ (9,143)
Cash used in operations			$ (20,900)
At The Market Common Stock Offering
Description Of Business [Line Items]
Number of shares issued and sold		0

Fair Value - Additional Information (Details)	3 Months Ended
Fair Value - Additional Information (Details)	Mar. 31, 2026
Recurring Basis \| Maximum
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Short-term investments effective maturity date	1 year

Commitments and Contingencies - Operating Lease Expense and Variable Lease Expense (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2026	Mar. 31, 2025
Commitments and Contingencies Disclosure [Abstract]
Operating lease expense	$ 88	$ 88
Variable lease expense	$ 27	$ 45

Stock-based Compensation - Summary of Stock Options Outstanding and Exercisable under the 2026 Plan, 2020 Plan and the 2024 Inducement Plan (Details) - $ / shares	3 Months Ended
	Mar. 31, 2026	Dec. 31, 2025
Share Based Compensation Shares Authorized Under Stock Option Plans Exercise Price Range [Line Items]
Options Outstanding	1,266,207	1,204,829
Options Exercisable	632,516
Exercise Price $3.13 to 7.14
Share Based Compensation Shares Authorized Under Stock Option Plans Exercise Price Range [Line Items]
Exercise Price ($) - Lower Limit	$ 3.13
Exercise Price ($) - Upper Limit	$ 7.14
Options Outstanding	630,351
Options Exercisable	112,845
Exercise Price $10.40 to 41.10
Share Based Compensation Shares Authorized Under Stock Option Plans Exercise Price Range [Line Items]
Exercise Price ($) - Lower Limit	$ 10.4
Exercise Price ($) - Upper Limit	$ 41.1
Options Outstanding	424,264
Options Exercisable	308,349
Exercise Price $89.3 to 199.40
Share Based Compensation Shares Authorized Under Stock Option Plans Exercise Price Range [Line Items]
Exercise Price ($) - Lower Limit	$ 89.3
Exercise Price ($) - Upper Limit	$ 199.4
Options Outstanding	185,933
Options Exercisable	185,663
Exercise Price $211.55 to 294.10
Share Based Compensation Shares Authorized Under Stock Option Plans Exercise Price Range [Line Items]
Exercise Price ($) - Lower Limit	$ 211.55
Exercise Price ($) - Upper Limit	$ 294.1
Options Outstanding	25,659
Options Exercisable	25,659

Condensed Consolidated Statements of Operations and Comprehensive Loss (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2026	Mar. 31, 2025
Operating expenses:
Research and development	$ 11,262	$ 4,302
Milestone liability change in fair value	(929)
General and administrative	6,881	5,234
Total operating expenses	17,214	9,536
Loss from operations	(17,214)	(9,536)
Other income, net	586	393
Sermonix pre-funded warrant change in fair value	(16,320)
Net loss	(32,948)	(9,143)
Unrealized (loss) gain on available-for-sale securities	(9)	(5)
Comprehensive loss attributable to common stockholders	$ (32,957)	$ (9,148)
Net loss per share attributable to common stockholders, basic	$ (1.73)	$ (2.34)
Net loss per share attributable to common stockholders, diluted	$ (1.73)	$ (2.34)
Weighted-average shares used in computing net loss per share attributable to common stockholders, basic	19,027,087	3,904,244
Weighted-average shares used in computing net loss per share attributable to common stockholders, diluted	19,027,087	3,904,244

Condensed Consolidated Balance Sheets (Unaudited) - USD ($) $ in Thousands	Mar. 31, 2026	Dec. 31, 2025
Current assets:
Cash and cash equivalents	$ 32,833	$ 69,276
Short-term investments	34,846	19,055
Prepaid expenses and other current assets	1,523	1,127
Total current assets	69,202	89,458
Restricted cash	631	631
Property and equipment, net	1,241	1,472
Operating lease right-of-use asset	461	535
Other long-term assets	55	55
Total assets	71,590	92,151
Current liabilities:
Accounts payable	1,764	4,587
Accrued liabilities	4,424	4,963
Sermonix pre-funded warrant		37,488
Current operating lease liability	478	465
Total current liabilities	6,666	47,503
Operating lease liability, less current portion	213	338
Milestone liability	14,187	15,116
Other long-term liabilities	1,221	1,404
Total liabilities	22,287	64,361
Stockholders' equity:
Common stock, $0.0001 par value;400,000,000 and 90,000,000 shares authorized at March 31,, 2026 and December 31, 2025, respectively; 9,393,514 and 9,335,913 shares issued and outstanding at March 31, 2026 and December 31, 2025, respectively	1	1
Additional paid-in capital	594,018	539,548
Accumulated other comprehensive (loss) income	(13)	(4)
Accumulated deficit	(544,703)	(511,755)
Total stockholders' equity	49,303	27,790
Total liabilities and stockholders' equity	$ 71,590	$ 92,151

Stock-based Compensation - Stock-based Compensation Expense Recognized (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2026	Mar. 31, 2025
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Stock-based compensation expense	$ 662	$ 1,637
Research and Development
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Stock-based compensation expense	265	568
General and Administrative
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Stock-based compensation expense	$ 397	$ 1,069

Commitments and Contingencies - Additional Information (Details)	3 Months Ended
	Mar. 31, 2026 USD ($)
Commitments And Contingencies [Line Items]
Litigation related accruals	$ 0
Laboratory and Office Facilities \| Bothell, Washington
Commitments And Contingencies [Line Items]
Operating lease expiration month and year	2027-08
Operating lease existence of option to extend	true
Operating lease, additional term of contract	5 years
Laboratory and Office Facilities \| Bothell, Washington \| Minimum
Commitments And Contingencies [Line Items]
Operating lease initial term	6 years 3 months 18 days
Laboratory and Office Facilities \| Bothell, Washington \| Maximum
Commitments And Contingencies [Line Items]
Operating lease initial term	7 years

Fair Value - Schedule of Changes in Fair Value Sermonix Pre-funded Warrant And Milestone Liability (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2026 USD ($)
Sermonix Pre-Funded Warrant
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
December 31, 2025	$ 37,488
Reclassified to equity	(53,808)
Change in fair value	16,320
March 31, 2026	0
Milestone liability
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
December 31, 2025	15,116
Reclassified to equity	0
Change in fair value	(929)
March 31, 2026	$ 14,187

Fair Value - Schedule of Fair Value Sermonix Pre-funded Warrant And Milestone Liability At Issuance (Details)	Mar. 31, 2026	Dec. 31, 2025
Fair Value of Common Stock \| Sermonix Pre-Funded Warrant
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Warrants and Rights Outstanding, Measurement Input		0.0757
Volatility \| Sermonix Pre-Funded Warrant
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Warrants and Rights Outstanding, Measurement Input		0.97
Risk-free rate \| Sermonix Pre-Funded Warrant
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Warrants and Rights Outstanding, Measurement Input		0.037
Dividend Yield \| Sermonix Pre-Funded Warrant
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Warrants and Rights Outstanding, Measurement Input		0
Holding period years \| Sermonix Pre-Funded Warrant
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Warrants and Rights Outstanding, Term		2 months 12 days
Weighted Average Cost of Capital \| Milestone liability
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Liability Measurement Input	0.12	0.11
Probability \| Milestone liability
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Liability Measurement Input	0.439	0.439

Pay vs Performance Disclosure - USD ($) $ in Thousands	3 Months Ended
Pay vs Performance Disclosure - USD ($) $ in Thousands	Mar. 31, 2026	Mar. 31, 2025
Pay vs Performance Disclosure
Net Income (Loss)	$ (32,948)	$ (9,143)

- Definition

The portion of profit or loss for the period, net of income taxes, which is attributable to the parent.

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Reference 38: http://www.xbrl.org/2003/role/disclosureRef
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Reference 44: http://www.xbrl.org/2003/role/disclosureRef
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+ Details

Stock-based Compensation (Tables)

3 Months Ended

Mar. 31, 2026

Share-Based Payment Arrangement [Abstract]

Stock-based Compensation Expense Recognized

Stock‑based compensation expense recognized was as follows (in thousands):


	Three Months Ended March 31,
	2026		2025
Research and development	$	265	$	568
General and administrative		397		1,069
Total stock-based compensation expense	$	662	$	1,637

Weighted-Average Assumptions used in Estimating Fair Value of each Stock Options using Black-Scholes Option-Pricing Model

The fair value of each stock option was estimated using the Black‑Scholes option‑pricing model with the following weighted-average assumptions:


	Three Months Ended March 31,
	2026			2025
Risk-free interest rate		3.84	%		3.98	%
Expected volatility		106.31	%		100.45	%
Expected term (in years)		6.08			6.03
Expected dividend yield		—			—

Summary of Option Activity Changes in Shares Available for Grant under the 2026 Plan, 2020 Plan and the 2024 Inducement Plan

Changes in shares available for grant under the 2026 Plan, the 2020 Plan, and the 2024 Inducement Plan during the three months ended March 31, 2026 were as follows:


	Shares Available for Grant
Shares available for grant at December 31, 2025		98,723
2020 Plan reserve increase on January 1, 2026		323,000
Options and restricted stock units granted		(61,378	)
Options and restricted stock units forfeited, cancelled, or expired		—
Shares available for grant at March 31, 2026		360,345
Termination of future use of 2020 Plan		(355,345	)
Shares reserved for issuance under 2026 Plan		5,700,000
Shares available for grant at March 31, 2026		5,705,000

Summary of Option Activity under the 2026 Plan, 2020 Plan and the 2024 Inducement Plan

A summary of stock option activity under the 2026 Plan, the 2020 Plan, and the 2024 Inducement Plan for the three months ended March 31, 2026 is as follows:


	Shares		Weighted- Average Exercise price per Share		Weighted- Average Remaining Contractual Term (in years)		Aggregate Intrinsic Value (in thousands)
Balance at December 31, 2025		1,204,829	$	37.44	8.14		$	2,030
Granted		61,378		5.04		—		—
Exercised		—		—		—		—
Forfeited/expired		—		—		—		—
Balance at March 31, 2026		1,266,207	$	35.87		7.99	$	3,894
Expected to vest		633,691	$	9.03		9.15	$	3,225
Options exercisable		632,516	$	62.76		6.83	$	669

Summary of Stock Options Outstanding and Exercisable under the 2026 Plan, 2020 Plan and the 2024 Inducement Plan

Stock options outstanding and exercisable under the 2026 Plan, 2020 Plan, and the 2024 Inducement Plan consisted of the following at March 31, 2026



Exercise Price ($)	Options Outstanding		Options Exercisable
3.13 to 7.14		630,351		112,845
10.40 to 41.10		424,264		308,349
89.3 to 199.40		185,933		185,663
211.55 to 294.10		25,659		25,659
Total		1,266,207		632,516

Summary of Restricted Stock Activity under 2026 Plan and 2020 Plan

A summary of restricted stock unit ("RSU") activity under the 2026 Plan and the 2020 Plan for the three months ended March 31, 2026 is as follows:


	Share Equivalent			Weighted- Average Grant Date Fair Value
Non-vested at December 31, 2025		57,601		$	3.76
Granted		—			—
Cancelled		—			—
Vested		(57,601	)		3.76
Non-vested at March 31, 2026		—

Condensed Consolidated Statements of Stockholders' Equity (Parenthetical) (Unaudited)		3 Months Ended
	Sep. 17, 2025	Mar. 31, 2026
Statement of Stockholders' Equity [Abstract]
Reverse stock split description		The Company effected a reverse stock split of its outstanding shares of common stock on September 17, 2025 where every ten shares of its common stock issued and outstanding was converted into one share of common stock. Any fractional post-split shares as a result of the reverse stock split were rounded down to the nearest whole post-split share. Stockholders of the Company previously authorized the Board of Directors to approve a reverse stock split at the Company's annual meeting on May 29, 2025. All share amounts and per share amounts disclosed in this Quarterly Report on Form 10-Q have been restated to reflect the reverse stock split on a retroactive basis in all periods presented.
Reverse stock split ratio	0.1

Stock-based Compensation - Additional Information (Details) - USD ($)	3 Months Ended
	Mar. 31, 2026	Mar. 31, 2025
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Expected dividend yield	0.00%
Fair value of options granted	$ 300,000	$ 300,000
Fair value of restricted stock units granted	0	200,000
Fair value of options vested	700,000	2,400,000
Aggregate intrinsic value of options exercised	0	$ 0
Unrecognized compensation cost	$ 4,200,000
Remaining weighted-average period expected to recognize unrecognized compensation cost	2 years 2 months 26 days
Restricted Stock Units (RSUs)
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Shares outstanding	$ 0

Accrued Liabilities

3 Months Ended

Mar. 31, 2026

Payables and Accruals [Abstract]

Accrued Liabilities

5. Accrued Liabilities

Accrued liabilities consisted of the following (in thousands):


	March 31,		December 31,
	2026		2025
Research and development	$	1,334	$	2,012
Employee compensation and benefits		1,218		1,948
Professional services and other		1,872		1,003
Total accrued liabilities	$	4,424	$	4,963

Commitments and Contingencies - Weighted Average Remaining Lease Term and Weighted Average Discount Rate to Determine the Operating Lease Liability (Details)	Mar. 31, 2026
Commitments and Contingencies Disclosure [Abstract]
Weighted average remaining lease term (years)	1 year 4 months 24 days
Weighted average discount rate	8.10%

Stock-based Compensation - Weighted-Average Assumptions used in Estimating Fair Value of each Stock Options using Black-Scholes Option-Pricing Model (Details)	3 Months Ended
	Mar. 31, 2026	Mar. 31, 2025
Share-Based Payment Arrangement [Abstract]
Risk-free interest rate	3.84%	3.98%
Expected volatility	106.31%	100.45%
Expected term (in years)	6 years 29 days	6 years 10 days

Common Stock - Schedule of Reserved Shares of Common Stock for Future Issuance (Details) - shares	Mar. 31, 2026	Dec. 31, 2025
Class Of Stock [Line Items]
Reserved shares of common stock for future issuance	65,802,983	60,128,329
Shares Issuable Upon the Exercise of Outstanding Common Stock Options and the Vesting of Outstanding Common Restricted Stock Units Granted
Class Of Stock [Line Items]
Reserved shares of common stock for future issuance	1,266,207	1,262,430
Shares Available for Future Grant under 2020 Equity Incentive Plan
Class Of Stock [Line Items]
Reserved shares of common stock for future issuance		63,723
Shares available for Future Grant under 2026 Equity Incentive Plan
Class Of Stock [Line Items]
Reserved shares of common stock for future issuance	5,700,000
Shares Available for Future Grant under Employee Stock Purchase Plan
Class Of Stock [Line Items]
Reserved shares of common stock for future issuance	221,354	156,754
Shares Available for Future Grant under 2024 Inducement Equity Incentive Plan
Class Of Stock [Line Items]
Reserved shares of common stock for future issuance	5,000	35,000
PIPE Pre-Funded Warrants
Class Of Stock [Line Items]
Reserved shares of common stock for future issuance	8,816,684	8,816,684
Series A Common Warrants
Class Of Stock [Line Items]
Reserved shares of common stock for future issuance	23,031,494	23,031,494
Series B Common Warrants
Class Of Stock [Line Items]
Reserved shares of common stock for future issuance	21,259,842	21,259,842
Sermonix Pre-funded Warrants
Class Of Stock [Line Items]
Reserved shares of common stock for future issuance	5,502,402	5,502,402

Net Loss Per Share Attributable to Common Stockholders

3 Months Ended

Mar. 31, 2026

Earnings Per Share [Abstract]

Net Loss Per Share Attributable to Common Stockholders

10. Net Loss Per Share Attributable to Common Stockholders

The following outstanding shares of potentially dilutive securities were excluded from the computation of the diluted net loss per share attributable to common stockholders for the periods presented because their effect would have been anti-dilutive:


	Three Months Ended March 31,
	2026		2025
Stock options to purchase common stock		1,266,207		913,117
Non-vested Restricted Stock Units		—		120,148
Employee stock purchase plan		3,248		4,717
Series A Common Warrants		23,031,494		—
Series B Common Warrants		21,259,842		—
Total		45,560,791		1,037,982

Common Stock

3 Months Ended

Mar. 31, 2026

Equity [Abstract]

Common Stock

8. Common Stock

Each share of common stock has the right to one vote. The holders of common stock are also entitled to receive dividends whenever funds are legally available and if declared by the Company’s board of directors, subject to the prior rights of holders of all classes of stock outstanding having priority rights as to dividends. No cash dividends have been declared by the board of directors from inception.

The Company has reserved the following shares of common stock for future issuance, on an as-converted basis, as follows:


	March 31,		December 31,
	2026		2025
Shares issuable upon the exercise of outstanding common stock options and the vesting of outstanding common restricted stock units granted		1,266,207		1,262,430
Shares available for future grant under the 2020 Equity Incentive Plan		—		63,723
Shares available for future grant under the 2026 Equity Incentive Plan		5,700,000		—
Shares available for future grant under the Employee Stock Purchase Plan		221,354		156,754
Shares available for future grant under the 2024 Inducement Equity Incentive Plan		5,000		35,000
PIPE Pre-Funded Warrants		8,816,684		8,816,684
Series A Common Warrants		23,031,494		23,031,494
Series B Common Warrants		21,259,842		21,259,842
Sermonix Pre-Funded Warrant		5,502,402		5,502,402
Total		65,802,983		60,128,329

2025 PIPE Financing

In December 2025, the Company entered into a securities purchase agreement (the “PIPE Securities Purchase Agreement”) with investors, pursuant to which the Company issued, by way of a private placement (the “Private Placement”) an aggregate of (i) 5,356,547 shares of the Company’s common stock, (ii) pre-funded warrants (the “PIPE Pre-Funded Warrants”) to purchase 8,816,684 shares of common stock, (iii) warrants (the “Series A Common Warrants”) to purchase 23,031,494 shares of common stock and/or shares underlying pre-funded warrants and (iv) warrants (the “Series B Common Warrants”) to purchase 21,259,842 shares of common stock and/or shares underlying pre-funded warrants. The aggregate gross proceeds from the Private Placement was $90.0 million. Issuance costs of $7.6 million are reflected as deduction from additional paid-in capital.

The PIPE Pre-Funded Warrants are exercisable at an exercise price of $0.001 per share, subject to customary adjustments and are exercisable at any time on or after issuance subject to the restriction discussed below.

The Series A Common Warrants have an exercise price of $6.35 per share and are exercisable after the earlier of (1) the latest of (a) June 30, 2026, (b) the date on which the Company publicly announces the enrollment of the 500th subject or the last subject, whichever is earlier, in the ELAINE-3 trial; and (c) the date on which the FDA approves or issues a complete response letter to Eli Lilly & Co.'s marketing application, including a supplement to a new drug application, for imlunestrant in combination with abemaciclib in breast cancer, and (2) October 31, 2026 ( the “Series A Common Warrant Initial Exercise Date”). The Series A Common Warrants will remain exercisable until the 30th day following the Series A Common Warrant Initial Exercise Date (the “Series A Common Warrant Termination Date”), except that if the Series A Common Warrant Initial Exercise Date has not occurred by December 23, 2030, then December 23, 2030 will be the Series A Common Warrant Termination Date.

The Series B Common Warrants have an exercise price of $7.62 per share and will be exercisable after the later of (1) June 30, 2026 and (2) the date of the completion of the public readout of topline results of the ELAINE-3 trial (the later of (1) and (2), the “Series B Common Warrant Initial Exercise Date”). The Series B Common Warrants will remain exercisable until the 30th day following the Series B Common Warrant Initial Exercise Date (the “Series B Common Warrant Termination Date”), except that if the Series B Common Warrant Initial Exercise Date has not occurred by December 23, 2030, then December 23, 2030 will be the Series B Common Warrant Termination Date. At issuance and at December 31, 2025, the PIPE Pre-Funded Warrants, Series A Common Warrants and Series B Common Warrants meet the criteria to be classified as equity instruments.

None of the PIPE Pre-Funded Warrants, the Series A Common Warrants or the Series B Common Warrants can be exercised if, immediately prior to or following such exercise, the applicable investor, together with its affiliates and any other persons whose beneficial ownership of shares of common stock would be aggregated with such investor for purposes of Section 13(d) of the Securities Exchange Act of 1934, as amended (the "Exchange Act"), would beneficially own more than 4.99%, 9.99% or 19.99%, at the election of such investor (in each case, the “PIPE Maximum Percentage”) of the total number of issued and outstanding shares of common stock following such exercise. If, upon exercise of the Series A Common Warrants or Series B Common Warrants, an investor would exceed the PIPE Maximum Percentage, then the Series A Common Warrants and Series B Common Warrants may be exercised for pre-funded warrants to purchase shares of common stock, which pre-funded warrants will have terms substantially the same as the PIPE Pre-Funded Warrants. The PIPE Maximum Percentage may be increased or decreased by an investor with 61 days’ written notice to the Company; provided, however, that such percentage may in no event exceed (x) 19.99% prior to a vote of our stockholders approving the removal of such exercise limitation or (y) with respect to certain investors, 4.99%.

As of March 31, 2026, no PIPE Pre-Funded Warrants, PIPE Series A Common Warrants or PIPE Series B Common Warrants have been exercised.

Sermonix Pre-Funded Warrant

As consideration for the rights granted to the Company under the Sermonix License Agreement entered into between the Company and Sermonix on December 18, 2025, the Company issued to Sermonix the Sermonix Pre-Funded Warrant to purchase 5,502,402 shares of the Company’s common stock pursuant to the Sermonix Securities Purchase Agreement.

The Sermonix Pre-Funded Warrant has an exercise price of $0.001 per share and is exercisable at any time after the date of approval from the Company’s stockholders as required by Nasdaq, including for purposes of Nasdaq Rule 5635(a), such that the Sermonix Pre-Funded Warrant can be exercised at any time without restriction or additional stockholder approval (the “Sermonix Stockholder Approval”). If the Sermonix Stockholder Approval was not obtained by the first anniversary of the original issuance of the Sermonix Pre-Funded Warrant, Sermonix had the right (the “Sermonix Redemption Right”) at any time and from time to time prior to such time that the Sermonix Stockholder Approval is obtained thereafter, to cause the Company to pay, at the

option of Sermonix, an amount up to (a) $6.35 (the “Sermonix Redemption Price”) multiplied by (b) the number of shares of common stock with respect to which Sermonix was exercising the Sermonix Redemption Right.

As a result of the Sermonix Redemption Right, the Company initially classified the Sermonix Pre-Funded Warrant as a liability in accordance with ASC 480. Because the redemption feature could require the Company to settle the warrant by transferring assets, the Sermonix Pre-Funded Warrant did not meet the criteria for equity classification.

On March 18, 2026, at the Company’s special meeting of its stockholders, the Company’s stockholders approved the proposal to permit the exercise of the Sermonix Pre-Funded Warrant under Nasdaq Rule 5635(a). As a result, the Sermonix Redemption Right lapsed and the Company determined the Sermonix Pre‑Funded Warrant met the criteria for equity classification. As a result, the Company remeasured the warrant to fair value immediately prior to reclassification, with the change in estimated fair value recorded as a non-cash gain or loss on the consolidated statements of operations and comprehensive loss for the three months ended March 31, 2026. Subsequently, the Company reclassified the Sermonix Pre-Funded Warrant to equity on March 18, 2026.

As of March 31, 2026, the Sermonix Pre-Funded Warrant has not been exercised in full or in part and remains outstanding.

Equity Incentive Plans

The Company’s board of directors (the “Board”) previously approved, subject to stockholder approval, the Company’s 2026 Equity Incentive Plan (the “2026 Plan”). At the Special Meeting, held on March 18, 2026, the Company’s stockholders approved the 2026 Plan. There will be no further grants under the Company’s prior company-wide equity plan, the 2020 Equity Incentive Plan (the “2020 Plan”), which terminated for future use upon stockholder approval of the 2026 Plan. Termination of the 2020 Plan did not affect outstanding awards previously issued pursuant to the 2020 Plan. A total of 5,700,000 shares of our common stock were reserved for issuance pursuant to our 2026 Plan. In addition, the shares reserved for issuance under our 2026 Plan will include any shares subject to awards granted under the 2020 Plan that, on or after the stockholder approval date of the 2026 Plan, are used to pay for the tax withholding related to the award or the exercise price with the award or, with respect to any options and stock appreciation rights, expire or become unexercisable without having been exercised in full, or with respect to any other types of awards under the 2020 Plan, are forfeited to or repurchased by the Company due to failure to vest, or are not issued under an award due to the award being paid out in cash rather than shares of common stock (provided that the maximum number of shares of common stock that may be added to the 2026 Plan pursuant to this sentence is 1,300,000 shares). The 2026 Plan provides for annual increases in the number of shares that may be issued under the 2026 Plan on January 1, 2027 and each subsequent January 1 thereafter by a number of shares equal to the least of, (1) 5% of the aggregate of outstanding shares of common stock and outstanding pre-funded warrants to purchase shares of common stock on the immediately preceding December 31, and (2) an amount determined by the Company’s board of directors.

The Company’s 2020 Plan provided for annual increases in the number of shares that may be issued under the 2020 Plan on January 1, 2021 and each subsequent January 1 thereafter by a number of shares equal to the least of (1) 323,000 shares, (2) 5% of the number of shares of common stock issued and outstanding on the immediately preceding December 31, and (3) an amount determined by the Company’s board of directors. The 2020 Plan terminated on March 18, 2026, the date the Company’s stockholders approved the 2026 Plan.

The Company’s 2020 Employee Stock Purchase Plan, or the ESPP, provides for annual increases in the number of shares that may be issued under the ESPP on January 1, 2021 and each subsequent January 1 thereafter by a number of shares equal to the least of (1) 64,600 shares, (2) 1% of the number of shares of common stock issued and outstanding on the immediately preceding December 31, and (3) an amount determined by the Company’s board of directors.

In February 2024, the board of directors adopted the Company's 2024 Inducement Equity Incentive Plan, or the 2024 Inducement Plan, and, subject to the adjustment provisions of the 2024 Inducement Plan, reserved 75,000 shares of the Company's common stock for issuance pursuant to equity awards granted under the 2024 Inducement Plan.

Effective January 1, 2026, the Company’s 2020 Plan and ESPP reserves increased by 323,000 shares and 64,600 shares, respectively.

- Definition

The entire disclosure for equity.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 815
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 8A
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480434/815-10-50-8A

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
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-Subparagraph (b)
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Reference 3: http://www.xbrl.org/2003/role/disclosureRef
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Reference 4: http://www.xbrl.org/2003/role/disclosureRef
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Reference 5: http://www.xbrl.org/2003/role/disclosureRef
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Reference 6: http://www.xbrl.org/2003/role/disclosureRef
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Reference 7: http://www.xbrl.org/2003/role/disclosureRef
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Reference 8: http://www.xbrl.org/2003/role/disclosureRef
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Reference 9: http://www.xbrl.org/2003/role/disclosureRef
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Reference 11: http://www.xbrl.org/2003/role/disclosureRef
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Reference 12: http://www.xbrl.org/2003/role/disclosureRef
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Reference 13: http://www.xbrl.org/2003/role/disclosureRef
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Reference 14: http://www.xbrl.org/2003/role/disclosureRef
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+ Details

Stock-based Compensation - Summary of Option Activity under the 2026 Plan, 2020 Plan and the 2024 Inducement Plan (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2026	Dec. 31, 2025
Share-Based Payment Arrangement [Abstract]
Shares, Beginning Balance	1,204,829
Shares, Granted	61,378
Shares, Forfeited/expired	0
Shares, Ending Balance	1,266,207	1,204,829
Shares, Expected to vest	633,691
Shares, Options exercisable	632,516
Weighted-Average Exercise price per Share, Beginning Balance	$ 37.44
Weighted-Average Exercise price per Share, Granted	5.04
Weighted-Average Exercise price per Share, Ending Balance	35.87	$ 37.44
Weighted-Average Exercise price per Share, Expected to vest	9.03
Weighted-Average Exercise price per Share, Options exercisable	$ 62.76
Weighted-Average Remaining Contractual Term (in years)	7 years 11 months 26 days	8 years 1 month 20 days
Weighted-Average Remaining Contractual Term, Expected to vest (in years)	9 years 1 month 24 days
Weighted-Average Remaining Contractual Term, Options exercisable (in years)	6 years 9 months 29 days
Aggregate Intrinsic Value, Outstanding Balance	$ 3,894	$ 2,030
Aggregate Intrinsic Value, Expected to vest	3,225
Aggregate Intrinsic Value, Options exercisable	$ 669

Description of Business

3 Months Ended

Mar. 31, 2026

Organization, Consolidation and Presentation of Financial Statements [Abstract]

Description of Business

1. Description of Business

Organization

LeonaBio, Inc. (the "Company") was incorporated as M3 Biotechnology, Inc. in the state of Washington on March 31, 2011 and reincorporated in the state of Delaware on October 27, 2015. In April 2019, the Company changed its name to Athira Pharma, Inc and in January 2026 the Company changed its name to LeonaBio, Inc. The Company currently has office and laboratory space in Bothell, Washington. The Company is a clinical-stage biopharmaceutical company dedicated to the development of novel therapeutics for high unmet medical needs, including treatment-resistant metastatic breast cancer and amyotrophic lateral sclerosis.

Liquidity and Capital Resources

Since the Company’s inception, it has funded its operations primarily with proceeds from the sale and issuance of common stock, convertible preferred stock, common stock warrants, prefunded common stock warrants, and convertible notes, and to a lesser extent from grant income and stock option exercises. From the Company’s inception through March 31, 2026, it has raised aggregate net cash proceeds of $489.8 million primarily from the issuance of its common stock (excluding option exercises), convertible preferred stock, common stock warrants, prefunded common stock warrants and convertible notes. In December 2025, the Company raised approximately $90 million in a Private Placement (as defined below), excluding placement agent fees and offering expenses. See Note 8 for more information.

As of March 31, 2026, the Company had cash, cash equivalents and investments of $67.7 million. The Company’s net loss for the three months ended March 31, 2026 was $32.9 million and cash used in operations for the three months ended March 31, 2026 was $20.9 million. Since the Company’s inception, it has devoted substantially all of its resources to its research and development efforts such as small molecule compound discovery, nonclinical studies and clinical trials, as well as manufacturing activities, establishing and maintaining the Company’s intellectual property portfolio, hiring personnel, raising capital, and providing general and administrative support for these operations.

Based upon the Company’s current operating plan, it estimates that its $67.7 million of cash, cash equivalents and investments at March 31, 2026 will be sufficient to fund its operating expenses and capital expenditure requirements through at least the next 12 months following the date of this Quarterly Report on Form 10-Q. Historically, the Company has incurred net losses from continuing operations and negative operating cash flows. The Company has not yet established an ongoing source of revenue sufficient to cover its operating costs; therefore, the Company expects it will need to continue to raise additional capital to accomplish its operating plan. The Company has a sales agreement in place with Cantor Fitzgerald & Co. and BTIG, LLC for an “at the market” equity offering facility through which it may offer and sell shares of its common stock, however, the Company is currently unable to offer and sell shares under this facility due to its ineligibility to use a Registration Statement on Form S-3 through December 2026. The Company has not sold any securities pursuant to this ATM offering. Should it be determined to be strategically advantageous, the Company could pursue public and private offerings of its equity securities similar to those the Company has previously completed, debt financings, or other strategic transactions, which could include income from collaboration, licensing or similar arrangements with third parties, or receiving research contributions, or grants.

Segment Reporting - Additional Information (Details)	3 Months Ended
Segment Reporting - Additional Information (Details)	Mar. 31, 2026 Segment
Segment Reporting [Abstract]
Number of operating segments	1
Segment Reporting, CODM, Profit (Loss) Measure, How Used, Description	The Company’s chief operating decision maker ("CODM"), its chief executive officer, reviews financial information on an aggregate basis for the purpose of allocating resources and assessing performance. When deciding how to allocate resources, the CODM reviews the financial results of the Company's drug candidate programs. The measure of segment assets is reported on the consolidated balance sheet as total assets.
Segment Reporting, CODM, Individual Title and Position or Group Name [Extensible Enumeration]	srt:ChiefExecutiveOfficerMember

Property and Equipment, Net - Schedule of Property and Equipment (Details) - USD ($) $ in Thousands	Mar. 31, 2026	Dec. 31, 2025
Property Plant And Equipment [Line Items]
Property and equipment, at cost	$ 5,739	$ 5,739
Less: accumulated depreciation	(4,498)	(4,267)
Property and equipment, net	1,241	1,472
Lab Equipment
Property Plant And Equipment [Line Items]
Property and equipment, at cost	705	705
Office Furniture, Fixtures, and Computer Equipment
Property Plant And Equipment [Line Items]
Property and equipment, at cost	712	712
Leasehold Improvement
Property Plant And Equipment [Line Items]
Property and equipment, at cost	$ 4,322	$ 4,322

Significant Accounting Policies - Schedule of Cash, Cash Equivalents and Restricted Cash (Details) - USD ($) $ in Thousands	Mar. 31, 2026	Dec. 31, 2025	Mar. 31, 2025	Dec. 31, 2024
Accounting Policies [Abstract]
Cash and cash equivalents	$ 32,833	$ 69,276
Restricted cash	631	631
Cash, cash equivalents and restricted cash	$ 33,464	$ 69,907	$ 27,053	$ 49,069

Stock-based Compensation - Summary of Option Activity Changes in Shares Available for Grant under the 2026 Plan, 2020 Plan and the 2024 Inducement Plan (Details)	3 Months Ended
	Mar. 31, 2026 shares
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Shares Available for Grant, Beginning Balance	98,723
Options and restricted stock units granted	(61,378)
Options and restricted stock units forfeited, cancelled, or expired	0
Shares Available for Grant, Ending Balance	360,345
Shares Available for Grant, Ending Balance	5,705,000
2020 Equity Incentive Plan
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Shares reserved	323,000
Termination of future use of 2020 Plan	(355,345)
2026 Equity Incentive Plan
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Shares reserved	5,700,000

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

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+ Details

Property and Equipment, Net - Additional Information (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2026	Mar. 31, 2025
Property, Plant and Equipment [Abstract]
Depreciation expense	$ 231	$ 243

Stock-based Compensation - Summary of Restricted Stock Activity under 2026 Plan and 2020 Plan (Details) - Restricted Stock Units (RSUs) - 2020 Equity Incentive Plan	3 Months Ended
	Mar. 31, 2026 $ / shares shares
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Share Equivalent, Non-vested, Beginning Balance	57,601
Share Equivalent, Granted	0
Share Equivalent, Cancelled	0
Share Equivalent, Vested	(57,601)
Share Equivalent, Non-vested, Ending Balance	0
Weighted-Average Grant Date Fair Value, Non-vested, Beginning Balance \| $ / shares	$ 3.76
Weighted-Average Grant Date Fair Value, Non-vested, Granted \| $ / shares	0
Weighted-Average Grant Date Fair Value, Non-vested, Cancelled \| $ / shares	0
Weighted-Average Grant Date Fair Value, Non-vested, Vested \| $ / shares	$ 3.76

Net Loss Per Share Attributable to Common Stockholders (Tables)

3 Months Ended

Mar. 31, 2026

Earnings Per Share [Abstract]

Summary of Dilutive Securities Excluded from Computation of Diluted Net Loss Per Share Attributable to Common Stockholders


	Three Months Ended March 31,
	2026		2025
Stock options to purchase common stock		1,266,207		913,117
Non-vested Restricted Stock Units		—		120,148
Employee stock purchase plan		3,248		4,717
Series A Common Warrants		23,031,494		—
Series B Common Warrants		21,259,842		—
Total		45,560,791		1,037,982

Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2026	Mar. 31, 2025
Operating activities
Net loss	$ (32,948)	$ (9,143)
Adjustments to reconcile net loss to net cash used in operating activities:
Milestone liability change in fair value	(929)
Change in fair value of Sermonix pre-funded warrant	16,320
Stock-based compensation	662	1,637
Depreciation expense	231	243
Non-cash lease expense	74	65
Amortization of premiums and accretion of discounts on available-for-sale securities, net	(260)	(65)
Changes in operating assets and liabilities:
Prepaid expenses and other current and long-term assets, net	(396)	353
Accounts payable and accrued liabilities	(3,362)	(7,655)
Operating lease liability	(112)	(100)
Other long-term liabilities	(183)
Net cash used in operating activities	(20,903)	(14,665)
Investing activities
Purchases of available-for-sale securities	(20,615)	(10,201)
Maturities of available-for-sale securities	5,075	2,850
Net cash (used in) provided by investing activities	(15,540)	(7,351)
Financing activities
Net increase (decrease) in cash, cash equivalents and restricted cash	(36,443)	(22,016)
Cash, cash equivalents and restricted cash, beginning of period	69,907	49,069
Cash, cash equivalents and restricted cash, end of period	$ 33,464	$ 27,053

Fair Value - Schedule of Assets And Liabilities Measured at Fair Value On Recurring Basis (Details) - USD ($) $ in Thousands	Mar. 31, 2026	Dec. 31, 2025
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Short-term investments	$ 34,846	$ 19,055
Recurring Basis
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total assets subject to fair value measurements on a recurring basis	57,282	71,209
Total liabilities subject to fair value measurements on a recurring basis	14,187	52,604
Recurring Basis \| Sermonix Pre-Funded Warrant
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total liabilities subject to fair value measurements on a recurring basis		37,488
Recurring Basis \| Milestone liability
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total liabilities subject to fair value measurements on a recurring basis	14,187	15,116
Recurring Basis \| Fair Value, Inputs, Level 1 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total assets subject to fair value measurements on a recurring basis	11	17,299
Recurring Basis \| Fair Value, Inputs, Level 2 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total assets subject to fair value measurements on a recurring basis	57,271	53,910
Recurring Basis \| Fair Value, Inputs, Level 3 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total liabilities subject to fair value measurements on a recurring basis	14,187	52,604
Recurring Basis \| Fair Value, Inputs, Level 3 [Member] \| Sermonix Pre-Funded Warrant
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total liabilities subject to fair value measurements on a recurring basis		37,488
Recurring Basis \| Fair Value, Inputs, Level 3 [Member] \| Milestone liability
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total liabilities subject to fair value measurements on a recurring basis	14,187	15,116
Recurring Basis \| Short-Term Investment [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Short-term investments	34,846	19,055
Recurring Basis \| Short-Term Investment [Member] \| Commercial Paper
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Short-term investments	8,414	5,209
Recurring Basis \| Short-Term Investment [Member] \| U.S. Government Debt and Agency Securities
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Short-term investments	26,432	13,846
Recurring Basis \| Short-Term Investment [Member] \| Fair Value, Inputs, Level 2 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Short-term investments	34,846	19,055
Recurring Basis \| Short-Term Investment [Member] \| Fair Value, Inputs, Level 2 [Member] \| Commercial Paper
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Short-term investments	8,414	5,209
Recurring Basis \| Short-Term Investment [Member] \| Fair Value, Inputs, Level 2 [Member] \| U.S. Government Debt and Agency Securities
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Short-term investments	26,432	13,846
Recurring Basis \| Cash Equivalents
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash equivalents, Fair Value	22,436	52,154
Recurring Basis \| Cash Equivalents \| Money Market Fund
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash equivalents, Fair Value	11	17,299
Recurring Basis \| Cash Equivalents \| Commercial Paper
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash equivalents, Fair Value	22,425	32,314
Recurring Basis \| Cash Equivalents \| U.S. Government Debt and Agency Securities
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash equivalents, Fair Value		2,541
Recurring Basis \| Cash Equivalents \| Fair Value, Inputs, Level 1 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash equivalents, Fair Value	11	17,299
Recurring Basis \| Cash Equivalents \| Fair Value, Inputs, Level 1 [Member] \| Money Market Fund
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash equivalents, Fair Value	11	17,299
Recurring Basis \| Cash Equivalents \| Fair Value, Inputs, Level 2 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash equivalents, Fair Value	22,425	34,855
Recurring Basis \| Cash Equivalents \| Fair Value, Inputs, Level 2 [Member] \| Commercial Paper
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash equivalents, Fair Value	$ 22,425	32,314
Recurring Basis \| Cash Equivalents \| Fair Value, Inputs, Level 2 [Member] \| U.S. Government Debt and Agency Securities
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash equivalents, Fair Value		$ 2,541

Net Loss Per Share Attributable to Common Stockholders - Summary of Dilutive Securities excluded from Computation of Diluted Net Loss Per Share Attributable to Common Stockholders (Details) - shares	3 Months Ended
	Mar. 31, 2026	Mar. 31, 2025
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Outstanding shares of potentially dilutive securities were excluded from the computation of the diluted net loss per share	45,560,791	1,037,982
Stock Options to Purchase Common Stock
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Outstanding shares of potentially dilutive securities were excluded from the computation of the diluted net loss per share	1,266,207	913,117
Non-vested Restricted Stock Units
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Outstanding shares of potentially dilutive securities were excluded from the computation of the diluted net loss per share	0	120,148
Employee Stock Purchase Plan
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Outstanding shares of potentially dilutive securities were excluded from the computation of the diluted net loss per share	3,248	4,717
Series A Common Warrants
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Outstanding shares of potentially dilutive securities were excluded from the computation of the diluted net loss per share	23,031,494	0
Series B Common Warrants
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Outstanding shares of potentially dilutive securities were excluded from the computation of the diluted net loss per share	21,259,842	0

Property and Equipment, Net (Tables)

3 Months Ended

Mar. 31, 2026

Property, Plant and Equipment [Abstract]

Schedule of Property and Equipment

Property and equipment consisted of the following (in thousands):


	March 31,			December 31,
	2026			2025
Lab equipment	$	705		$	705
Office furniture, fixtures, and computer equipment		712			712
Leasehold improvement		4,322			4,322
Property and equipment, at cost		5,739			5,739
Less: accumulated depreciation		(4,498	)		(4,267	)
Property and equipment, net	$	1,241		$	1,472

Commitments and Contingencies

3 Months Ended

Mar. 31, 2026

Commitments and Contingencies Disclosure [Abstract]

Commitments and Contingencies

7. Commitments and Contingencies

Legal Proceedings

From time to time, the Company may be subject to various legal proceedings or claims that arise in the ordinary course of business. The Company accrues a liability when the Company's management believes that it is both probable that a liability has been incurred and the amount of loss can be reasonably estimated. There were no material litigation-related accruals recorded as of March 31, 2026.

Operating Leases

The Company has operating leases for laboratory and office facilities in Bothell, Washington that expire in August 2027. The initial terms of the leases range from 6.3 to 7 years and the Company has options to extend the leases for an additional five years that it is not reasonably certain to exercise. As of March 31, 2026, the Company was not party to any finance leases.

The following table reconciles the Company’s undiscounted operating lease cash flows to its operating lease liability (in thousands):


	March 31, 2026
2026	$	383
2027		346
Total undiscounted lease payments		729
Present value adjustment for minimum lease commitments		(38	)
Net lease liability	$	691

The weighted average remaining lease term and the weighted average discount rate used to determine the operating lease liability were as follows:


	March 31, 2026
Weighted average remaining lease term (years)		1.4
Weighted average discount rate		8.1	%

Operating lease expense and variable lease expense consisted of the following (in thousands):


	Three Months Ended March 31,
	2026		2025
Operating lease expense	$	88	$	88
Variable lease expense		27		45

Fair Value (Tables)

3 Months Ended

Mar. 31, 2026

Fair Value Disclosures [Abstract]

Schedule of Assets And Liabilities Measured at Fair Value On Recurring Basis

The following table summarizes the Company’s assets and liabilities measured at fair value on a recurring basis and their respective input levels based on the fair value hierarchy (in thousands):


	March 31, 2026
	Level 1		Level 2		Level 3		Total
Assets:
Cash equivalents:
Money market fund	$	11	$	—	$	—	$	11
Commercial paper		—		22,425		—		22,425
Total cash equivalents		11		22,425		—		22,436
Short-term investments:
Commercial paper		—		8,414		—		8,414
U.S. government debt and agency securities		—		26,432		—		26,432
Total short-term investments	$	—		34,846	$	—	$	34,846

Total assets subject to fair value measurements on a recurring basis	$	11	$	57,271	$	—	$	57,282

Liabilities:
Milestone liability		—		—		14,187		14,187
Total liabilities subject to fair value measurements on a recurring basis	$	—	$	—	$	14,187	$	14,187


	December 31, 2025
	Level 1		Level 2		Level 3		Total
Assets:
Cash equivalents:
Money market fund	$	17,299	$	—	$	—	$	17,299
U.S. government debt and agency securities		—		2,541		—		2,541
Commercial paper		—		32,314		—		32,314
Total cash equivalents		17,299		34,855		—		52,154
Short-term investments:
Commercial paper		—		5,209		—		5,209
U.S. government debt and agency securities		—		13,846		—		13,846
Total short-term investments		—		19,055		—		19,055
Total assets subject to fair value measurements on a recurring basis	$	17,299	$	53,910	$	—	$	71,209

Liabilities:
Sermonix pre-funded warrant	$	—	$	—	$	37,488		37,488
Milestone liability		—		—		15,116		15,116
Total liabilities subject to fair value measurements on a recurring basis	$	—	$	—	$	52,604	$	52,604

Schedule of Fair Value Sermonix Pre-funded Warrant And Milestone Liability At Issuance

The key inputs into the fair value of the Sermonix Pre-Funded Warrant at December 31, 2025 were as follows:


	Sermonix Pre-Funded Warrant
				December 31, 2025
Fair Value of Common Stock				$	7.57
Volatility					97.0	%
Risk-free rate					3.7	%
Dividend Yield					0.0	%
Holding period years					0.20

	Milestone Liability
	March 31, 2026			December 31, 2025
Weighted Average Cost of Capital		12.0	%		11.0	%
Probability		43.9	%		43.9	%

Schedule of Changes in Fair Value Sermonix Pre-funded Warrant And Milestone Liability

The Company determines the fair value of the Milestone Liability based on the probability weighted present value of the net milestone payment and classifies as Level 3 due to the use of unobservable market data for identical or similar liabilities. The key inputs into the fair value of the Milestone Liability at December 31, 2025 and at March 31, 2026 were as follows:


	Sermonix Pre-Funded Warrant			Milestone Liability
December 31, 2025	$	37,488		$	15,116
Change in fair value		16,320			(929	)
Reclassified to equity		(53,808	)		-
March 31, 2026	$	-		$	14,187

Schedule of Fair Value of Cash Equivalents and Short-term Investments

The following tables reflect the Company’s financial asset balances measured at fair value on a recurring basis (in thousands):


	March 31, 2026
	Level	Amortized Cost		Unrealized Gains		Unrealized Losses			Fair Value
Cash equivalents:
Money market fund	1	$	11	$	—	$	—		$	11
Commercial paper	2		22,429		—		(4	)		22,425
Total cash equivalents		$	22,440	$	—	$	(4	)	$	22,436
Short-term investments:
Commercial paper	2		8,416		—		(2	)		8,414
U.S. government debt and agency securities	2		26,439		—		(7	)		26,432
Total short-term investments		$	34,855	$	—	$	(9	)	$	34,846


	December 31, 2025
	Level	Amortized Cost		Unrealized Gains		Unrealized Losses			Fair Value
Cash equivalents:
Money market fund	1	$	17,299	$	—	$	—		$	17,299
U.S. government debt and agency securities	2		2,541		—		—			2,541
Commercial paper	2		32,319		—		(5	)		32,314
Total cash equivalents		$	52,159	$	—	$	(5	)	$	52,154
Short-term investments:
Commercial paper	2		5,210		—		(1	)		5,209
U.S. government debt and agency securities	2		13,844		2		—			13,846
Total short-term investments		$	19,054	$	2	$	(1	)	$	19,055

Property and Equipment, Net

3 Months Ended

Mar. 31, 2026

Property, Plant and Equipment [Abstract]

Property and Equipment, Net

4. Property and Equipment, Net

Property and equipment consisted of the following (in thousands):


	March 31,			December 31,
	2026			2025
Lab equipment	$	705		$	705
Office furniture, fixtures, and computer equipment		712			712
Leasehold improvement		4,322			4,322
Property and equipment, at cost		5,739			5,739
Less: accumulated depreciation		(4,498	)		(4,267	)
Property and equipment, net	$	1,241		$	1,472

Depreciation expense was $0.2 million and $0.2 million for the three months ended March 31, 2026 and 2025, respectively.

Fair Value - Schedule of Fair Value of Cash Equivalents and Short-term Investments (Details) - USD ($) $ in Thousands	Mar. 31, 2026	Dec. 31, 2025
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Cash equivalents, Amortized Cost	$ 32,833	$ 69,276
Recurring Basis \| Short-term Investments
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Investments, Amortized Cost	34,855	19,054
Investments, Unrealized Gains		2
Investments, Unrealized Losses	(9)	(1)
Investments, Fair Value	34,846	19,055
Recurring Basis \| Short-term Investments \| Commercial Paper \| Level 2
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Investments, Amortized Cost	8,416	5,210
Investments, Unrealized Losses	(2)	(1)
Investments, Fair Value	8,414	5,209
Recurring Basis \| Short-term Investments \| U.S. Government Debt and Agency Securities \| Level 2
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Investments, Amortized Cost	26,439	13,844
Investments, Unrealized Gains		2
Investments, Unrealized Losses	(7)
Investments, Fair Value	26,432	13,846
Recurring Basis \| Cash Equivalents
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Cash equivalents, Amortized Cost	22,440	52,159
Cash equivalents, Unrealized Losses	(4)	(5)
Cash equivalents, Fair Value	22,436	52,154
Recurring Basis \| Cash Equivalents \| Level 1
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Cash equivalents, Fair Value	11	17,299
Recurring Basis \| Cash Equivalents \| Level 2
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Cash equivalents, Fair Value	22,425	34,855
Recurring Basis \| Cash Equivalents \| Money Market Fund
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Cash equivalents, Fair Value	11	17,299
Recurring Basis \| Cash Equivalents \| Money Market Fund \| Level 1
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Cash equivalents, Amortized Cost	11	17,299
Cash equivalents, Fair Value	11	17,299
Recurring Basis \| Cash Equivalents \| Commercial Paper
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Cash equivalents, Fair Value	22,425	32,314
Recurring Basis \| Cash Equivalents \| Commercial Paper \| Level 2
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Cash equivalents, Amortized Cost	22,429	32,319
Cash equivalents, Unrealized Losses	(4)	(5)
Cash equivalents, Fair Value	$ 22,425	32,314
Recurring Basis \| Cash Equivalents \| U.S. Government Debt and Agency Securities
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Cash equivalents, Fair Value		2,541
Recurring Basis \| Cash Equivalents \| U.S. Government Debt and Agency Securities \| Level 2
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Cash equivalents, Amortized Cost		2,541
Cash equivalents, Fair Value		$ 2,541

Insider Trading Arrangements	3 Months Ended
Insider Trading Arrangements	Mar. 31, 2026
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

Condensed Consolidated Statements of Operations and Comprehensive Loss (Unaudited) (Parenthetical)		3 Months Ended
	Sep. 17, 2025	Mar. 31, 2026
Statement of Comprehensive Income [Abstract]
Reverse stock split ratio	0.1
Reverse stock split description		The Company effected a reverse stock split of its outstanding shares of common stock on September 17, 2025 where every ten shares of its common stock issued and outstanding was converted into one share of common stock. Any fractional post-split shares as a result of the reverse stock split were rounded down to the nearest whole post-split share. Stockholders of the Company previously authorized the Board of Directors to approve a reverse stock split at the Company's annual meeting on May 29, 2025. All share amounts and per share amounts disclosed in this Quarterly Report on Form 10-Q have been restated to reflect the reverse stock split on a retroactive basis in all periods presented.

Significant Accounting Policies - Additional Information (Details)		3 Months Ended
	Sep. 17, 2025 shares	Mar. 31, 2026 $ / shares shares	Mar. 18, 2026 $ / shares shares	Dec. 31, 2025 $ / shares shares	Sep. 16, 2025 shares	Dec. 31, 2024 shares
Basis Of Presentation And Significant Accounting Policies [Line Items]
Stockholders' Equity, Reverse Stock Split		The Company effected a reverse stock split of its outstanding shares of common stock on September 17, 2025 where every ten shares of its common stock issued and outstanding was converted into one share of common stock. Any fractional post-split shares as a result of the reverse stock split were rounded down to the nearest whole post-split share. Stockholders of the Company previously authorized the Board of Directors to approve a reverse stock split at the Company's annual meeting on May 29, 2025. All share amounts and per share amounts disclosed in this Quarterly Report on Form 10-Q have been restated to reflect the reverse stock split on a retroactive basis in all periods presented.
Reverse stock split ratio	0.1
Number of authorized shares of capital	190,000,000		500,000,000			1,000,000,000
Number of common stock shares authorized	90,000,000	400,000,000	400,000,000	90,000,000	900,000,000
Number of preferred stock shares authorized			100,000,000
Common stock, par value per share \| $ / shares		$ 0.0001	$ 0.0001	$ 0.0001
Preferred stock, par value per share \| $ / shares			$ 0.0001

Segment Reporting - Schedule of Segment Profit or Loss (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2026	Mar. 31, 2025
Segment Reporting Information [Line Items]
Research and development expenses	$ 9,976	$ 3,637
General and administrative expenses	6,345	4,019
Other segment expenses	893	1,880
Total operating expenses	17,214	9,536
Loss from operations	(17,214)	(9,536)
Other income, net	586	393
Sermonix pre-funded warrant change in fair value	16,320
Net loss	(32,948)	(9,143)
Sermonix Pre-funded Warrants
Segment Reporting Information [Line Items]
Sermonix pre-funded warrant change in fair value	(16,320)	0
Lasofoxifene
Segment Reporting Information [Line Items]
Research and development expenses	8,629	0
Fosgonimeton (ATH-1017)
Segment Reporting Information [Line Items]
Research and development expenses	183	1,307
ATH-1105
Segment Reporting Information [Line Items]
Research and development expenses	243	924
ATH-1020
Segment Reporting Information [Line Items]
Research and development expenses	0	5
Preclinical Programs and Other Costs
Segment Reporting Information [Line Items]
Research and development expenses	355	403
Milestone liability
Segment Reporting Information [Line Items]
Research and development expenses	(929)	0
Personnel-Related Costs, Excluding Stock- Based Compensation
Segment Reporting Information [Line Items]
Research and development expenses	$ 1,495	$ 998

Segment Reporting (Tables)

3 Months Ended

Mar. 31, 2026

Segment Reporting [Abstract]

Schedule of Segment Profit or Loss

The table below is a summary of the segment profit or loss, including significant segment expenses (in thousands):


	Three Months Ended March 31,
	2026			2025
Research and development expenses:
Lasofoxifene		8,629			—
Fosgonimeton (ATH-1017)		183			1,307
ATH-1105		243			924
ATH-1020		-			5
Preclinical programs and other costs		355			403
Milestone liability change in fair value		(929	)		—
Personnel-related costs, excluding stock- based compensation		1,495			998
Total research and development expenses		9,976			3,637
General and administrative expenses		6,345			4,019
Other segment expenses(a)		893			1,880
Total operating expenses		17,214			9,536
Loss from operations		(17,214	)		(9,536	)
Other income, net	586			393
Sermonix pre-funded warrant change in fair value		(16,320	)		—
Net loss		(32,948	)	$	(9,143	)

(a)Other segment expenses includes stock-based compensation and depreciation expenses.

Document and Entity Information - shares	3 Months Ended
Document and Entity Information - shares	Mar. 31, 2026	May 05, 2026
Cover [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Mar. 31, 2026
Document Fiscal Year Focus	2026
Document Fiscal Period Focus	Q1
Entity Registrant Name	LeonaBio, Inc.
Entity Central Index Key	0001620463
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Current Fiscal Year End Date	--12-31
Entity Filer Category	Non-accelerated Filer
Entity Common Stock, Shares Outstanding		9,393,514
Entity Shell Company	false
Entity Small Business	true
Entity Emerging Growth Company	false
Entity File Number	001-39503
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	45-3368487
Entity Address, Address Line One	18706 North Creek Parkway
Entity Address, Address Line Two	Suite 104
Entity Address, City or Town	Bothell
Entity Address, State or Province	WA
Entity Address, Postal Zip Code	98011
City Area Code	425
Local Phone Number	620-8501
Document Quarterly Report	true
Document Transition Report	false
Security12b Title	Common Stock, $0.0001 par value per share
Trading Symbol	LONA
Security Exchange Name	NASDAQ

Stock-based Compensation

3 Months Ended

Mar. 31, 2026

Share-Based Payment Arrangement [Abstract]

Stock-based Compensation

9. Stock-based Compensation

Stock‑based compensation expense recognized was as follows (in thousands):


	Three Months Ended March 31,
	2026		2025
Research and development	$	265	$	568
General and administrative		397		1,069
Total stock-based compensation expense	$	662	$	1,637

Valuation Assumptions

The fair value of stock options was determined using the Black-Scholes option-pricing model and the assumptions below. Each of these inputs is subjective and generally required significant judgment.

•

Fair Value of Common Stock—The fair value of each share of common stock is based on the closing price of the Company’s common stock on the date of grant, or other relevant determination date, as reported on The Nasdaq Capital Market.

•

Risk-Free Interest Rate—The risk-free interest rate is based on the U.S. Treasury zero coupon issues in effect at the time of grant for periods corresponding with the expected term of the option.

•

Expected Volatility—Because the Company was previously privately held and did not have any trading history for its common stock, the expected volatility was estimated based on the average volatility for comparable publicly traded life sciences companies over a period equal to the expected term of the stock option grants. The comparable companies were chosen based on the similar size, stage in life cycle or area of specialty. 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 that the stock-based awards are expected to be outstanding and is determined using the simplified method (based on the midpoint between the vesting date and the end of the contractual term) as the Company has limited history of relevant stock option exercise activity.

•

Expected Dividend Yield—The Company has never paid dividends on its common stock and has no plans to pay dividends going forward. Therefore, it used an expected dividend yield of zero.

The fair value of each stock option was estimated using the Black‑Scholes option‑pricing model with the following weighted-average assumptions:


	Three Months Ended March 31,
	2026			2025
Risk-free interest rate		3.84	%		3.98	%
Expected volatility		106.31	%		100.45	%
Expected term (in years)		6.08			6.03
Expected dividend yield		—			—

The grant date fair value of RSUs is based upon the fair market value of the Company’s common stock based on its closing price as reported on the date of grant on the Nasdaq Capital Market.

The fair value of options granted during the three months ended March 31, 2026 and 2025 was $0.3 million and $0.3 million, respectively. There were no RSUs granted during the three months ended March 31, 2026. The fair value of RSUs granted during the three months ended March 31, 2025 was $0.2 million.

Stock Option Activity

Changes in shares available for grant under the 2026 Plan, the 2020 Plan, and the 2024 Inducement Plan during the three months ended March 31, 2026 were as follows:


	Shares Available for Grant
Shares available for grant at December 31, 2025		98,723
2020 Plan reserve increase on January 1, 2026		323,000
Options and restricted stock units granted		(61,378	)
Options and restricted stock units forfeited, cancelled, or expired		—
Shares available for grant at March 31, 2026		360,345
Termination of future use of 2020 Plan		(355,345	)
Shares reserved for issuance under 2026 Plan		5,700,000
Shares available for grant at March 31, 2026		5,705,000

A summary of stock option activity under the 2026 Plan, the 2020 Plan, and the 2024 Inducement Plan for the three months ended March 31, 2026 is as follows:


	Shares		Weighted- Average Exercise price per Share		Weighted- Average Remaining Contractual Term (in years)		Aggregate Intrinsic Value (in thousands)
Balance at December 31, 2025		1,204,829	$	37.44	8.14		$	2,030
Granted		61,378		5.04		—		—
Exercised		—		—		—		—
Forfeited/expired		—		—		—		—
Balance at March 31, 2026		1,266,207	$	35.87		7.99	$	3,894
Expected to vest		633,691	$	9.03		9.15	$	3,225
Options exercisable		632,516	$	62.76		6.83	$	669

The total fair value of options granted that vested during the three months ended March 31, 2026 and 2025 was $0.7 million and $2.4 million, respectively.

The aggregate intrinsic value in the table above is calculated as the difference between the exercise price of the underlying options and the estimated fair value of the Company’s common stock underlying all options that were in-the-money at March 31, 2026. There were no options exercised during the three months ended March 31, 2026 and 2025. As of March 31, 2026, there was $4.2 million of total unrecognized compensation cost related to non-vested stock options. The Company expects to recognize this cost over a remaining weighted-average period of 2.24 years. The Company utilizes newly issued shares to satisfy option exercises.

Stock options outstanding and exercisable under the 2026 Plan, 2020 Plan, and the 2024 Inducement Plan consisted of the following at March 31, 2026



Exercise Price ($)	Options Outstanding		Options Exercisable
3.13 to 7.14		630,351		112,845
10.40 to 41.10		424,264		308,349
89.3 to 199.40		185,933		185,663
211.55 to 294.10		25,659		25,659
Total		1,266,207		632,516

Restricted Stock Unit Activity

A summary of restricted stock unit ("RSU") activity under the 2026 Plan and the 2020 Plan for the three months ended March 31, 2026 is as follows:


	Share Equivalent			Weighted- Average Grant Date Fair Value
Non-vested at December 31, 2025		57,601		$	3.76
Granted		—			—
Cancelled		—			—
Vested		(57,601	)		3.76
Non-vested at March 31, 2026		—

As of March 31, 2026, there were no RSUs outstanding.

Significant Accounting Policies

3 Months Ended

Mar. 31, 2026

Accounting Policies [Abstract]

Significant Accounting Policies

2. Significant Accounting Policies

Basis of Presentation

Unaudited Interim Condensed Consolidated Financial Statements

Fair Value Measurements

Level 1—Unadjusted quoted prices in active markets that are accessible at the measurement date for identical, unrestricted assets or liabilities.

Level 2—Quoted prices in markets that are not active or financial instruments for which all significant inputs are observable, either directly or indirectly.

Cash, cash equivalents and restricted cash


	March 31,		December 31,
	2026		2025
Cash and cash equivalents	$	32,833	$	69,276
Restricted cash		631		631
Cash, cash equivalents and restricted cash	$	33,464	$	69,907

Short-term Investments

Warrants

Use of Estimates

Research and Development Expenses

Contingent consideration arrangements

General and Administrative Expenses

Leases

Stock-based Compensation

Net Loss Per Share Attributable to Common Stockholders

Common Stock (Tables)

3 Months Ended

Mar. 31, 2026

Equity [Abstract]

Schedule of Reserved Shares of Common Stock for Future Issuance

The Company has reserved the following shares of common stock for future issuance, on an as-converted basis, as follows:


	March 31,		December 31,
	2026		2025
Shares issuable upon the exercise of outstanding common stock options and the vesting of outstanding common restricted stock units granted		1,266,207		1,262,430
Shares available for future grant under the 2020 Equity Incentive Plan		—		63,723
Shares available for future grant under the 2026 Equity Incentive Plan		5,700,000		—
Shares available for future grant under the Employee Stock Purchase Plan		221,354		156,754
Shares available for future grant under the 2024 Inducement Equity Incentive Plan		5,000		35,000
PIPE Pre-Funded Warrants		8,816,684		8,816,684
Series A Common Warrants		23,031,494		23,031,494
Series B Common Warrants		21,259,842		21,259,842
Sermonix Pre-Funded Warrant		5,502,402		5,502,402
Total		65,802,983		60,128,329

Segment Reporting

3 Months Ended

Mar. 31, 2026

Segment Reporting [Abstract]

Segment Reporting

6. Segment Reporting

The Company operates as a single operating segment, which is the business of developing and commercializing therapeutics. The Company’s chief operating decision maker ("CODM"), its chief executive officer, reviews financial information on an aggregate basis for the purpose of allocating resources and assessing performance. When deciding how to allocate resources, the CODM reviews the financial results of the Company's drug candidate programs. The measure of segment assets is reported on the consolidated balance sheet as total assets.

The table below is a summary of the segment profit or loss, including significant segment expenses (in thousands):


	Three Months Ended March 31,
	2026			2025
Research and development expenses:
Lasofoxifene		8,629			—
Fosgonimeton (ATH-1017)		183			1,307
ATH-1105		243			924
ATH-1020		-			5
Preclinical programs and other costs		355			403
Milestone liability change in fair value		(929	)		—
Personnel-related costs, excluding stock- based compensation		1,495			998
Total research and development expenses		9,976			3,637
General and administrative expenses		6,345			4,019
Other segment expenses(a)		893			1,880
Total operating expenses		17,214			9,536
Loss from operations		(17,214	)		(9,536	)
Other income, net	586			393
Sermonix pre-funded warrant change in fair value		(16,320	)		—
Net loss		(32,948	)	$	(9,143	)

(a)Other segment expenses includes stock-based compensation and depreciation expenses.

- Definition

The entire disclosure for reporting segments including data and tables. Reportable segments include those that meet any of the following quantitative thresholds a) it's reported revenue, including sales to external customers and intersegment sales or transfers is 10 percent or more of the combined revenue, internal and external, of all operating segments b) the absolute amount of its reported profit or loss is 10 percent or more of the greater, in absolute amount of 1) the combined reported profit of all operating segments that did not report a loss or 2) the combined reported loss of all operating segments that did report a loss c) its assets are 10 percent or more of the combined assets of all operating segments.

+ References

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+ Details

Significant Accounting Policies (Tables)

3 Months Ended

Mar. 31, 2026

Accounting Policies [Abstract]

Schedule of Cash, Cash Equivalents and Restricted Cash


	March 31,		December 31,
	2026		2025
Cash and cash equivalents	$	32,833	$	69,276
Restricted cash		631		631
Cash, cash equivalents and restricted cash	$	33,464	$	69,907

Commitments and Contingencies - Reconciliation of Undiscounted Operating Lease Cash Flows to Operating Lease Liability Payments (Details) $ in Thousands	Mar. 31, 2026 USD ($)
Commitments and Contingencies Disclosure [Abstract]
2026	$ 383
2027	346
Total undiscounted lease payments	729
Present value adjustment for minimum lease commitments	(38)
Net lease liability	$ 691

Condensed Consolidated Statements of Stockholders' Equity (Unaudited) - USD ($) $ in Thousands	Total	Common Stock	Additional Paid-In Capital	Accumulated Other Comprehensive Income (Loss)	Accumulated Deficit
Beginning balance at Dec. 31, 2024	$ 44,841	$ 0	$ 450,986	$ 1	$ (406,146)
Beginning balance, shares at Dec. 31, 2024		3,904,049
Issuance of common stock upon vesting of restricted stock units, shares		150
Stock-based compensation	1,637		1,637
Unrealized (loss) gain on available-for-sale securities	(5)			(5)
Net loss	(9,143)				(9,143)
Ending balance at Mar. 31, 2025	37,330	$ 0	452,623	(4)	(415,289)
Ending balance, shares at Mar. 31, 2025		3,904,199
Beginning balance at Dec. 31, 2025	27,790	$ 1	539,548	(4)	(511,755)
Beginning balance, shares at Dec. 31, 2025		9,335,913
Issuance of common stock upon vesting of restricted stock units, shares		57,601
Stock-based compensation	662		662
Reclassification of Sermonix Pre-funded warrant to equity	53,808		53,808
Unrealized (loss) gain on available-for-sale securities	(9)			(9)
Net loss	(32,948)				(32,948)
Ending balance at Mar. 31, 2026	$ 49,303	$ 1	$ 594,018	$ (13)	$ (544,703)
Ending balance, shares at Mar. 31, 2026		9,393,514

- Definition

The portion of profit or loss for the period, net of income taxes, which is attributable to the parent.

+ References

+ Details

- Definition

Amount of equity (deficit) attributable to parent. Excludes temporary equity and equity attributable to noncontrolling interest.

+ References

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+ Details

Accrued Liabilities - Schedule of Accrued Liabilities (Details) - USD ($) $ in Thousands	Mar. 31, 2026	Dec. 31, 2025
Payables and Accruals [Abstract]
Research and development	$ 1,334	$ 2,012
Employee compensation and benefits	1,218	1,948
Professional services and other	1,872	1,003
Total accrued Liabilities	$ 4,424	$ 4,963

Common Stock - Additional Information (Details) - USD ($) $ / shares in Units, $ in Millions		3 Months Ended	12 Months Ended
	Mar. 18, 2026	Mar. 31, 2026	Dec. 31, 2025	Jan. 01, 2026	Dec. 18, 2025	Feb. 29, 2024
Class Of Stock [Line Items]
Reserved shares of common stock for future issuance		65,802,983	60,128,329
Issuance costs from PIPE financing			$ (7.6)
PIPE Pre-Funded Warrants
Class Of Stock [Line Items]
Number of shares issued and sold			5,356,547
Exercise Price			$ 0.001
Series A Common Warrants
Class Of Stock [Line Items]
Warrants sale price per share			6.35
Sermonix Pre-Funded Warrant
Class Of Stock [Line Items]
Class of warrant					5,502,402
Exercise Price			0.001
Redemption price per share			$ 6.35
Private Placement
Class Of Stock [Line Items]
Proceeds from Issuance of Common Stock			$ 90.0
2020 Equity Incentive Plan
Class Of Stock [Line Items]
Share based compensation maximum annual increase in number of shares that may be issued under the plan		323,000
Share based compensation percentage of number shares of common stock issued and outstanding on immediate proceeding		5.00%
Reserved shares of common stock for future issuance				323,000
2020 Employee Stock Purchase Plan
Class Of Stock [Line Items]
Share based compensation maximum annual increase in number of shares that may be issued under the plan		64,600
Share based compensation percentage of number shares of common stock issued and outstanding on immediate proceeding		1.00%
Reserved shares of common stock for future issuance				64,600
2024 Inducement Equity Incentive Plan
Class Of Stock [Line Items]
Reserved shares of common stock for future issuance						75,000
2025 PIPE Financing \| PIPE Pre-Funded Warrants
Class Of Stock [Line Items]
Class of warrant			8,816,684
Beneficial ownership			4.99%
2025 PIPE Financing \| Series A Common Warrants
Class Of Stock [Line Items]
Class of warrant			23,031,494
Beneficial ownership			9.99%
2025 PIPE Financing \| Series B Common Warrants
Class Of Stock [Line Items]
Class of warrant			21,259,842
Exercise Price			$ 7.62
Beneficial ownership			19.99%
2026 Equity Incentive Plan
Class Of Stock [Line Items]
Share based compensation maximum annual increase in number of shares that may be issued under the plan	1,300,000
Reserved shares of common stock for future issuance	5,700,000
Share based compensation percentage number of shares of outstanding shares of common stock and outstanding pre-funded warrants to purchase shares of common stock	5.00%

Condensed Consolidated Balance Sheets (Parenthetical) (Unaudited)	Mar. 31, 2026 $ / shares shares	Dec. 31, 2025 $ / shares shares
Statement of Financial Position [Abstract]
Common stock, par value \| $ / shares	$ 0.0001	$ 0.0001
Common stock, shares authorized	400,000,000	90,000,000
Common stock, shares issued	9,393,514	9,335,913
Common stock, shares outstanding	9,393,514	9,335,913

Fair Value

3 Months Ended

Mar. 31, 2026

Fair Value Disclosures [Abstract]

Fair Value

. Fair Value

The following table summarizes the Company’s assets and liabilities measured at fair value on a recurring basis and their respective input levels based on the fair value hierarchy (in thousands):


	March 31, 2026
	Level 1		Level 2		Level 3		Total
Assets:
Cash equivalents:
Money market fund	$	11	$	—	$	—	$	11
Commercial paper		—		22,425		—		22,425
Total cash equivalents		11		22,425		—		22,436
Short-term investments:
Commercial paper		—		8,414		—		8,414
U.S. government debt and agency securities		—		26,432		—		26,432
Total short-term investments	$	—		34,846	$	—	$	34,846

Total assets subject to fair value measurements on a recurring basis	$	11	$	57,271	$	—	$	57,282

Liabilities:
Milestone liability		—		—		14,187		14,187
Total liabilities subject to fair value measurements on a recurring basis	$	—	$	—	$	14,187	$	14,187


	December 31, 2025
	Level 1		Level 2		Level 3		Total
Assets:
Cash equivalents:
Money market fund	$	17,299	$	—	$	—	$	17,299
U.S. government debt and agency securities		—		2,541		—		2,541
Commercial paper		—		32,314		—		32,314
Total cash equivalents		17,299		34,855		—		52,154
Short-term investments:
Commercial paper		—		5,209		—		5,209
U.S. government debt and agency securities		—		13,846		—		13,846
Total short-term investments		—		19,055		—		19,055
Total assets subject to fair value measurements on a recurring basis	$	17,299	$	53,910	$	—	$	71,209

Liabilities:
Sermonix pre-funded warrant	$	—	$	—	$	37,488		37,488
Milestone liability		—		—		15,116		15,116
Total liabilities subject to fair value measurements on a recurring basis	$	—	$	—	$	52,604	$	52,604

U.S government debt and agency securities and commercial paper are classified as Level 2 as they were valued based upon quoted market prices for similar instruments in active markets, quoted prices for identical or similar instruments in markets that are not active, and model-based valuation techniques for which all significant inputs are observable in the market or can be corroborated by observable market data for substantially the full term of the assets.

Due to a contingent redemption right exercisable if the Company failed to obtain stockholder approval permitting the exercise of the Sermonix Pharmaceuticals, Inc. (“Sermonix”) Pre‑Funded Warrant under Nasdaq Rule 5635(a) within one year of issuance, the warrant was classified as a liability pursuant to ASC 480 as of December 31, 2025. As of December 31, 2025 the Company determined the fair value of the Sermonix Pre-Funded Warrant based on the fair value of the Company’s common stock, adjusted for a discount for lack of marketability, and classified it as Level 3 due to the use of unobservable market data for identical or similar liabilities. Following receipt of stockholder approval on March 18, 2026, the redemption right lapsed and the Sermonix Pre‑Funded Warrant met the criteria for equity classification. Accordingly, the Company remeasured the warrant to fair value immediately prior to reclassification and reclassified the warrant to equity as of March 18, 2026. Following reclassification, the Sermonix Pre‑Funded Warrant is no longer subject to recurring fair value measurement.

The key inputs into the fair value of the Sermonix Pre-Funded Warrant at December 31, 2025 were as follows:


	Sermonix Pre-Funded Warrant
				December 31, 2025
Fair Value of Common Stock				$	7.57
Volatility					97.0	%
Risk-free rate					3.7	%
Dividend Yield					0.0	%
Holding period years					0.20

	Milestone Liability
	March 31, 2026			December 31, 2025
Weighted Average Cost of Capital		12.0	%		11.0	%
Probability		43.9	%		43.9	%

As of December 31, 2025 and March 31, 2026, Level 3 liabilities include the milestone payable to Sermonix pursuant to the Company’s license agreement executed on December 18, 2025 (the “Milestone Liability”). The Milestone Liability is classified as a liability under ASC 480 as the Company is contingently obligated to settle the milestone through the transfer of assets or issuance of a variable number of equity shares with a value equal to a fixed monetary amount.


	Sermonix Pre-Funded Warrant			Milestone Liability
December 31, 2025	$	37,488		$	15,116
Change in fair value		16,320			(929	)
Reclassified to equity		(53,808	)		-
March 31, 2026	$	-		$	14,187

The fair value of the Level 3 liabilities may change significantly as additional data is obtained. In evaluating this information, considerable judgment is required to interpret the data used to develop the assumptions and estimates. Accordingly, the use of different market assumptions and/or different valuation techniques may have a material effect on the estimated fair value amounts, and such changes could materially impact the Company’s results of operations in future periods.

The following tables reflect the Company’s financial asset balances measured at fair value on a recurring basis (in thousands):


	March 31, 2026
	Level	Amortized Cost		Unrealized Gains		Unrealized Losses			Fair Value
Cash equivalents:
Money market fund	1	$	11	$	—	$	—		$	11
Commercial paper	2		22,429		—		(4	)		22,425
Total cash equivalents		$	22,440	$	—	$	(4	)	$	22,436
Short-term investments:
Commercial paper	2		8,416		—		(2	)		8,414
U.S. government debt and agency securities	2		26,439		—		(7	)		26,432
Total short-term investments		$	34,855	$	—	$	(9	)	$	34,846


	December 31, 2025
	Level	Amortized Cost		Unrealized Gains		Unrealized Losses			Fair Value
Cash equivalents:
Money market fund	1	$	17,299	$	—	$	—		$	17,299
U.S. government debt and agency securities	2		2,541		—		—			2,541
Commercial paper	2		32,319		—		(5	)		32,314
Total cash equivalents		$	52,159	$	—	$	(5	)	$	52,154
Short-term investments:
Commercial paper	2		5,210		—		(1	)		5,209
U.S. government debt and agency securities	2		13,844		2		—			13,846
Total short-term investments		$	19,054	$	2	$	(1	)	$	19,055

All the commercial paper, U.S. government debt and agency securities, U.S. treasury bills, and corporate bonds designated as short-term investments have an effective maturity date that is equal to or less than one year from the respective balance sheet date.

As of March 31, 2026, the Company does not intend to sell any securities in unrealized loss positions, and it is not more-likely-than-not that the Company will be required to sell such securities prior to the recovery of the amortized cost basis. Based on the Company's assessment, the Company concluded all impairments as of March 31, 2026 to be due to factors other than credit loss, such as changes in interest rates. A credit loss allowance was not recognized and the unrealized losses for available-for-sale securities were recorded in other comprehensive loss.

- Definition

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

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 820
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
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-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482106/820-10-50-2

Reference 2: http://www.xbrl.org/2003/role/exampleRef
-Topic 820
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-Section 55
-Paragraph 107
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482078/820-10-55-107

Reference 3: http://www.xbrl.org/2003/role/exampleRef
-Topic 820
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-Section 55
-Paragraph 100
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482078/820-10-55-100

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
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-Name Accounting Standards Codification
-Section 50
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-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482106/820-10-50-2

Reference 5: http://www.xbrl.org/2003/role/disclosureRef
-Topic 820
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-Name Accounting Standards Codification
-Section 50
-Paragraph 6A
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482106/820-10-50-6A

Reference 6: http://www.xbrl.org/2003/role/disclosureRef
-Topic 820
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2E
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-URI https://asc.fasb.org/1943274/2147482106/820-10-50-2E

Reference 7: http://www.xbrl.org/2003/role/disclosureRef
-Topic 820
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 6A
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-URI https://asc.fasb.org/1943274/2147482106/820-10-50-6A

Reference 8: http://www.xbrl.org/2003/role/disclosureRef
-Topic 820
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-Name Accounting Standards Codification
-Section 50
-Paragraph 6A
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Reference 9: http://www.xbrl.org/2003/role/disclosureRef
-Topic 820
-SubTopic 10
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-Section 50
-Paragraph 6A
-Subparagraph (e)
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-URI https://asc.fasb.org/1943274/2147482106/820-10-50-6A

Reference 10: http://www.xbrl.org/2003/role/disclosureRef
-Topic 820
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-Name Accounting Standards Codification
-Section 50
-Paragraph 6A
-Subparagraph (d)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482106/820-10-50-6A

Reference 11: http://www.xbrl.org/2003/role/disclosureRef
-Topic 820
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (h)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482106/820-10-50-2

Reference 12: http://www.xbrl.org/2003/role/disclosureRef
-Topic 820
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (g)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482106/820-10-50-2

Reference 13: http://www.xbrl.org/2003/role/disclosureRef
-Topic 940
-SubTopic 820
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147478119/940-820-50-1

+ Details

Commitments and Contingencies (Tables)

3 Months Ended

Mar. 31, 2026

Commitments and Contingencies Disclosure [Abstract]

Reconciliation of Undiscounted Operating Lease Cash Flows to Operating Lease Liability Payments

The following table reconciles the Company’s undiscounted operating lease cash flows to its operating lease liability (in thousands):


	March 31, 2026
2026	$	383
2027		346
Total undiscounted lease payments		729
Present value adjustment for minimum lease commitments		(38	)
Net lease liability	$	691

Weighted Average Remaining Lease Term and Weighted Average Discount Rate and Operating Lease Expense and Variable Lease Expense

The weighted average remaining lease term and the weighted average discount rate used to determine the operating lease liability were as follows:


	March 31, 2026
Weighted average remaining lease term (years)		1.4
Weighted average discount rate		8.1	%

Operating lease expense and variable lease expense consisted of the following (in thousands):


	Three Months Ended March 31,
	2026		2025
Operating lease expense	$	88	$	88
Variable lease expense		27		45

Accrued Liabilities (Tables)

3 Months Ended

Mar. 31, 2026

Payables and Accruals [Abstract]

Schedule of Accrued Liabilities

Accrued liabilities consisted of the following (in thousands):


	March 31,		December 31,
	2026		2025
Research and development	$	1,334	$	2,012
Employee compensation and benefits		1,218		1,948
Professional services and other		1,872		1,003
Total accrued liabilities	$	4,424	$	4,963