Stock-Based Compensation

12 Months Ended

Dec. 31, 2025

Share-Based Payment Arrangement [Abstract]

2024 Stock Option and Grant Plan

In 2024, in connection with the Company’s IPO, the board of directors adopted, and the Company’s shareholders approved the 2024 Stock Option and Grant Plan (the “2024 Plan”) under which the Company may grant equity-based incentive awards to the Company’s employees, officers, directors, consultants and other key persons of the Company and its affiliates upon whose judgment, initiative, and efforts the Company largely depends for the successful conduct of its business. Following the effectiveness of the 2024 Plan, no shares remained available for future issuance under the 2019 Stock Option and Grant Plan (as amended, the “2019 Plan”). Any other options or awards outstanding under the 2019 Plan remain outstanding and effective.

The 2024 Plan initially allowed the Company to grant awards up to 2,453,616 shares of Common Stock, plus shares of Common Stock subject to awards outstanding under the 2019 Plan that are forfeited, canceled, held back upon exercise of an option or settlement of an award to cover the exercise price or tax withholding, reacquired by the Company prior to vesting, satisfied without the issuance of stock or otherwise terminated (other than by exercise). Each year starting on January 1, 2025 and on each January 1 thereafter, the number of shares of stock reserved and available for issuance under the 2024 Plan shall automatically be cumulatively increased by 5% of the outstanding shares on the immediately preceding December 31 or such lesser number of shares as approved by the Company. During the year ended December 31, 2025, the Company registered 2,722,001 additional shares of Common Stock for issuance under the 2024 Plan in connection with this automatic annual increase. Through December 31, 2025, the Company issued 2,849,554 options under the 2024 Plan. The terms of equity award agreements, including vesting requirements, were determined by the board of directors and are subject to the provisions of the 2024 Plan. Equity awards granted to employees and non-employees generally vest over a four-year period but may be granted with different vesting terms. Certain options provide for early vesting.

Stock options granted to employees and non-employees expire no more than 10 years from the date of grant and are generally service based. The 2024 Plan allows for awards to contain performance-based vesting criteria and for such awards that are deemed probable of vesting, the Company records expense in the period in which such determination is made through any estimated remaining vested period. No awards with performance-based vesting criteria have been granted.

2019 Stock Option and Grant Plan

Prior to the approval of the 2024 Plan, the Company granted awards under the 2019 Plan which originally provided for options, restricted stock awards (“RSA”), unrestricted stock awards and restricted stock units to the Company’s employees, officers, directors, consultants and advisors.

Under the 2019 Plan, as amended, the Company was authorized to issue up to 8,856,245 shares of Common Stock. The terms of equity award agreements, including vesting requirements, were determined by the board of directors and were subject to the provisions of the 2019 Plan. Equity awards granted to employees and non-employees generally vested over one to four years. Certain options provide for early vesting.

RSAs were issued under individual RSA agreements (the “Award Agreements”). The Award Agreements dictated vesting terms and once vested, the recipients’ restricted stock may not be sold, assigned, transferred, pledged or otherwise encumbered or disposed of except as specifically provided in the respective Award Agreement.

Stock options granted to employees and non-employees expire no more than 10 years from the date of grant and are generally service based. The 2019 Plan allowed awards containing performance-based vesting criteria and for such awards that were deemed probable of vesting, the Company recorded expense in the period in which such determination was made through any estimated remaining vested period. As of the effectiveness of the 2024 Plan, the Company ceased making awards under the 2019 Plan.

Stock-Based Compensation Expense

The Company recognized total stock-based compensation expense for non-employees and employees in its statements of operations as follows (in thousands):


	Year Ended December 31,
	2025		2024
Research and development	$	5,568	$	2,084
General and administrative	9,438		5,313
Total	$	15,006	$	7,397

Restricted Stock Awards

There were no unvested RSAs and unrecognized compensation costs as of December 31, 2025 or 2024. All outstanding RSAs vested in 2024.

Stock Options

Stock-based compensation, measured at the grant date based on the fair value of the award, is typically recognized ratably over the requisite service period, using the straight-line method of expense attribution. When utilizing the Black-Scholes option-pricing model to determine the grant date fair value of stock options granted to employees or non-employees, we used the following weighted average assumptions:


	Year Ended December 31,
	2025		2024
Risk-free interest rate	3.67% - 4.36%		3.8	%
Expected term (in years)	5.3 - 6.1		6.1
Expected annual dividend yield	—	%	—	%
Expected volatility	90.63% - 95.38%		90.8	%
Fair Value of common stock	$7.35 - $14.44		$5.45 - $24.43

Using the Black-Scholes option pricing model, the weighted-average grant date fair value of stock options granted during the years ended December 31, 2025 and 2024 was $14.40 and $7.46 per share, respectively.

A summary of options award activity for non-employees and employees of the Company is as follows:


	Shares	Weighted-Average Exercise Price		Weighted Average - Remaining Contractual Life (years)	Aggregate Intrinsic Value(1) (in thousands)
Outstanding at December 31, 2024	8,038,679	$	7.02
Granted	2,559,847	14.40
Exercised	(556,711)	4.98
Canceled	(190,838)	8.22
Outstanding as of December 31, 2025	9,850,977	$	9.03	8.5	$	90,401

Exercisable as of December 31, 2025	3,071,744	$	6.78	7.9	$	31,120
Exercisable and expected to vest as of December 31, 2025	9,850,977	$	9.03	8.5	$	90,401

(1) The aggregate intrinsic values is calculated as the difference between the exercise price of the underlying options and the fair value of the Company’s common stock on December 31, 2025 for the options that were in the money.

The aggregate intrinsic value of options exercised for the years ended December 31, 2025 and 2024 were $6.4 million and $1.2 million, respectively.

The Company had 6,779,233 unvested stock options outstanding as of December 31, 2025. As of December 31, 2025, total unrecognized compensation costs of $46.9 million related to unvested stock options are expected to be recognized as expense over a weighted average period of 2.9 years.

On September 5, 2024, the Company’s board of directors adopted, and its stockholders approved, the 2024 Employee Stock Purchase Plan (the "ESPP"), which became effective September 5, 2024. The ESPP initially reserves and authorizes the issuance of up to 507,383 shares of our common stock to participating employees. The ESPP provides that the number of shares reserved and available for issuance will automatically increase on January

1, 2025 and each January 1 thereafter through January 1, 2034, by the least of (i) 1,014,766 shares of common stock, (ii) 1% of the sum of (A) the number of shares of our common stock issued and outstanding on the immediately preceding December 31, and (B) the number of shares of common stock issuable pursuant to the exercise of any outstanding, pre-funded warrants to acquire such common stock for a nominal exercise price on the immediately preceding December 31, or (iii) such number of shares of common stock as determined by the administrator of the ESPP. The number of shares reserved under the ESPP is subject to adjustment in the event of a stock split, stock dividend, or other change in our capitalization. There has been no activity on this plan to date, and no stock-based compensation expense was recognized during the year ended December 31, 2025.