The Company’s 2024 Equity Incentive Plan (the “2024 Plan”) provides for the Company to sell or issue common stock or restricted stock, or to grant incentive stock options or nonqualified stock options for the purchase of common stock, to employees, directors and consultants of the Company.

The total number of common shares that may be issued under the 2024 Plan was 15,517,688 shares as of March 31, 2026, of which 1,030,020 shares remained available for future grant.

The 2024 Plan is administered by the Board, or its delegee. The exercise prices, vesting and other restrictions are determined at the discretion of the Board, or its delegee, except that the exercise price per share of stock options may not be less than 100% of the fair market value of the common stock on the date of grant and the term of the stock option may not be greater than ten years. For any person who owns stock possessing more than 10% of the total combined voting power of all classes of stock of the Company or any affiliate, the exercise price per share of incentive stock options may not be less than 110% of the fair market value of the share of common stock on the date of grant. The Company generally grants stock-based awards with service conditions only (“service-based” awards) which generally vest over three or four years. The Company also has granted performance-based awards which vest upon the achievement of specified events. Stock options generally expire after ten years.

The assumptions that the Company used to determine the grant-date fair value of stock options granted were as follows, presented on a weighted-average basis:


	Three Months Ended March 31,
	2026			2025
Expected option life (years)	6.1				6.0
Risk-free interest rate		3.8	%		4.1	%
Expected volatility		81.8	%		78.3	%
Expected dividend yield		—	%		—	%

The following table summarizes the Company’s stock option activity during the three months ended March 31, 2026:


	Number of options			Weighted- average exercise price		Weighted- average remaining contractual term (years)	Aggregate intrinsic value
Outstanding as of December 31, 2025		13,470,409		$	6.20	9.17	$	52,398
Granted		1,572,649			10.65
Exercised		(10,905	)		5.25
Cancelled or forfeited		(574,437	)		6.34
Outstanding as of March 31, 2026		14,457,716		$	6.68	9.03	$	70,560
Exercisable at March 31, 2026		3,124,983		$	5.38	8.01	$	19,313

The aggregate intrinsic value of stock options is calculated as the difference between the exercise price of the underlying stock options and the estimated fair value of the Company’s common stock for those stock options that had exercise prices lower than the estimated fair value of the Company’s common stock at March 31, 2026.

The weighted-average grant-date fair value of the Company’s stock options granted for the three months ended March 31, 2026 and 2025 was $7.68 and $3.80, respectively.

Stock-based compensation expense was allocated as follows (in thousands):


	Three Months Ended March 31,
	2026		2025
Research and development	$	973	$	217
General and administrative		2,966		1,306
Total stock-based compensation expense	$	3,939	$	1,523

As of March 31, 2026, total unrecognized compensation cost related to the unvested stock-based awards with service-based vesting conditions was $52.9 million, which is expected to be recognized over a weighted-average period of 3.1 years.