In January 2024, the Company’s board of directors adopted, and stockholders approved, the Company’s 2024 Equity Incentive Plan (the “2024 Plan”), which became effective on February 6, 2024. The 2024 Plan superseded the Company’s 2019 Equity Incentive Plan (the “2019 Plan”). No share awards can be granted under the 2019 Plan from the effective date of the 2024 Plan. Shares subject to outstanding equity awards granted under the 2019 Plan may be added to the 2024 Plan as such shares become available from time to time if awards terminate, expire, or lapse for any reason without the delivery of shares, or are reacquired or withheld (or not issued) to satisfy a tax withholding obligation or the purchase or exercise price.

As of June 30, 2025, 3,571,058 incentive stock options, nonstatutory stock options and restricted stock units had been granted under the 2024 Plan. As of June 30, 2025, 2,804,687 shares of the Company’s common stock were reserved for future issuance under the 2024 Plan.

In January 2024, the Company’s board of directors and stockholders adopted the Company’s 2024 Employee Stock Purchase Plan (the “ESPP”), which became effective on February 6, 2024. As of June 30, 2025, 844,000 shares of common stock were reserved for future issuance under the ESPP.

In September 2024, the Company adopted the 2024 Inducement Equity Incentive Plan (the “Inducement Plan”). As of June 30, 2025, 3,804,259 shares were granted and 195,741 shares were available for future grant under the Inducement Plan.

Stock options issued under the 2019 Plan, 2024 Plan and the Inducement Plan generally vest over a four-year period and expire ten years from the date of grant. Certain options provide for accelerated vesting if there is a change in control, as defined in the individual award agreements and the Company’s severance policies.

A summary of option activity under the 2019 Plan, 2024 Plan and the Inducement Plan is as follows:


	Number of Options			Weighted- Average Exercise Price Per Share		Weighted- Average Remaining Contractual Term (in years)		Aggregate Intrinsic Value (in thousands)
Outstanding at December 31, 2024		7,595,922		$	5.83		7.58	$	760
Options granted		3,667,200		$	2.52
Options exercised		(3,955	)	$	0.73
Options forfeited		(1,124,945	)	$	4.89
Options expired		(195,283	)	$	4.46
Outstanding at June 30, 2025		9,938,939		$	4.74		8.51	$	2,161
Exercisable at June 30, 2025*		1,876,685		$	4.83		4.76	$	59
Vested and expected to vest at June 30, 2025		9,938,939		$	4.74		8.51	$	2,161

* Includes 70,066 shares of unvested stock options for which the holders have the right to early exercise such options as of June 30, 2025.

Aggregate intrinsic value represents the difference between the fair value of the underlying common stock and the exercise price. The weighted-average grant date fair value of options granted for the three and six months ended June 30, 2025 was $1.89 and $1.99, respectively. The weighted-average grant date fair value of options granted for the three and six months ended June 30, 2024 was $6.22 and $14.89, respectively. The total fair value of options that vested during the three and six months ended June 30, 2025 was $1.7 million and $4.6 million, respectively. The total fair value of options that vested during the three and six months ended June 30, 2024 was $0.5 million and $1.0 million, respectively. The intrinsic value of options exercised during the three and six months ended June 30, 2025 was zero and less than $0.1 million, respectively, and is calculated as the difference between the exercise price and the fair value of common stock as of the exercise date. The intrinsic value of options exercised during the three and six months ended June 30, 2024 was $0.3 million and $3.5 million, respectively. As of June 30, 2025, total unrecognized stock-based compensation expense was $30.4 million, which is expected to be recognized over a weighted-average period of 3.1 years.

During the three and six months ended June 30, 2025, the Company granted Restricted Stock Units (“RSUs”) for 731,929 and 843,929 shares, respectively, with a weighted-average grant date fair value per share of $2.29 and $2.34, respectively. RSU shares vest over a four-year period. The fair value of the RSUs equals the fair value of the Company's common stock as of the grant date. The estimated fair value of RSUs granted during the three and six months ended June 30,

2025 was $1.7 million and $2.0 million, respectively. During the three and six months ended June 30, 2024, the Company granted RSUs for 5,000 shares with a weighted-average grant date fair value per share of $8.03 and a total estimated fair value of less than $0.1 million. As of June 30, 2025, total unrecognized compensation expense for RSUs was $3.9 million, which is expected to be recognized over a weighted-average period of 3.2 years.


	Number of RSUs			Weighted- Average Grant Date Fair Value
Unvested at December 31, 2024		549,001		$	7.19
Granted – RSUs		843,929			2.34
Vested – RSUs		(40,792	)		8.04
Forfeited – RSUs		(103,609	)		5.11
Unvested at June 30, 2025		1,248,529		$	4.06

During the year ended December 31, 2024, the Company granted performance RSUs for 100,000 shares with a weighted-average grant date fair value per share of $8.05. There was no activity for performance RSUs during the three and six months ended June 30, 2025. Performance RSU shares vest in full upon the Company receiving certain regulatory approvals within 36 months from the grant date. The fair value of the performance RSUs equals the fair value of the Company's common stock as of the grant date. The estimated fair value of performance RSUs granted was $0.8 million. As of June 30, 2025, total unrecognized compensation expense for performance RSUs was $0.8 million. Compensation expense of $0.8 million for performance RSUs is expected to be recognized when it is probable that the performance criteria will be achieved over the remaining vesting term. As of June 30, 2025, the performance criteria was not probable and no expense was recognized.

The Black-Scholes option pricing model, used to estimate fair value of the option awards, requires the use of the following assumptions:

The fair value of options granted was estimated using the Black-Scholes valuation model using the following assumptions for the three and six months ended June 30, 2025 and 2024, respectively:


	Three Months Ended June 30,		Six Months Ended June 30,
	2025	2024	2025	2024
Expected volatility	95.1% - 97.6%	92.9% - 93.2%	95.1% - 97.6%	92.9% - 93.5%
Expected dividend yield	0%	0%	0%	0%
Expected term (in years)	5.50-6.08	5.93-6.01	5.35-6.08	5.93-6.08
Risk-free interest rate	3.9%-4.2%	4.3%	3.9%-4.5%	4.1%-4.3%

The following table presents the classification of stock-based compensation expense related to stock options granted (in thousands):


	Three Months Ended June 30,				Six Months Ended June 30,
	2025		2024		2025		2024
Research and development	$	898	$	695	$	1,704	$	1,277
General and administrative		1,620		589		2,975		2,285
Total stock-based compensation expense	$	2,518	$	1,284	$	4,679	$	3,562

In January 2024, in connection with the Former CEO note forgiveness (see Note 8), the Company recognized stock-based compensation expense of $1.1 million in general and administrative expenses in the statement of operations and comprehensive loss for the six months ended June 30, 2024.