As of March 31, 2026, there is an aggregate of approximately 1.4 million shares of common stock available for issuance under the Company’s equity incentive plans, including 0.1 million shares of common stock remain available for issuance under the Amended and Restated 2017 Employee Stock Purchase Plan.

The following table presents, on a weighted average basis, the assumptions used in the Black-Scholes option-pricing model to determine the grant-date fair value of stock options granted:


	Three Months Ended March 31,
	2026		2025
Risk-free interest rate	3.8	%	4.3	%
Expected term (in years)	6.0		6.1
Expected volatility	109.9	%	103.9	%
Expected dividend yield	0	%	0	%

As of March 31, 2026, total unrecognized compensation expense related to unvested stock options and restricted stock units was $19.8 million, which is expected to be recognized over a weighted average period of 2.9 years.

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


	Number of Shares	Weighted Average Exercise Price		Weighted Average Contractual Term (Years)	Aggregate Intrinsic Value (in thousands)
Outstanding as of December 31, 2025	12,080,718	$	2.34	9.6	$	28,329
Granted	3,860,000	3.99

Forfeited and expired	(84,654)	19.73			$	—
Outstanding as of March 31, 2026	15,856,064	$	2.65	9.4	$	30,395
Exercisable as of March 31, 2026	850,519	$	8.52	9.1	$	1,765
Vested and expected to vest as of March 31, 2026	12,771,903	$	2.72	9.4	$	24,717

The aggregate intrinsic value of options is calculated as the difference between the exercise price of the stock options and the fair value of the Company’s common stock to the extent the stock option had a lower exercise price. There were no options exercised in 2025 and 2024. The weighted average grant-date fair value per share of stock options granted during the three months ended March 31, 2026 and 2025 was $3.36 and $14.10, respectively.


	Number of Shares	Weighted-Average Grant Date Fair Value
Unvested as of December 31, 2025	73,381	$	15.48

Vested	(12,776)	9.72
Forfeited	(6,195)	16.56
Unvested as of March 31, 2026	54,410	$	16.71

Outstanding restricted stock units include performance-based restricted stock units (“PRSUs”), which will vest based on the achievement of an operational milestone. The Company considers the achievement of the remaining operational milestone related to outstanding PRSUs to be probable. Stock-based compensation expense has been recognized for these awards using the accelerated attribution model based on the fair value of the awards as of the date of grant and management’s best estimate of the date the probable operational milestone will be achieved. The Company updates its estimates related to the probability and timing of achievement of the operational milestones each period until the award either vests or is forfeited.

Stock-based compensation expense was classified in the condensed consolidated statements of operations and comprehensive (loss) income as follows:


	Three Months Ended March 31,
(in thousands)	2026		2025
Research and development expense	$	715	$	259
General and administrative expense	1,698		260
Total stock-based compensation	$	2,413	$	519