In 2019, the Company adopted the 2019 Equity Incentive Plan (the 2019 Plan). The 2019 Plan provided for the Company to grant qualified stock options, non-qualified stock options, and restricted stock awards to employees, non-employee directors and consultants of the Company under terms and provisions established by the Company’s board of directors. Under the terms of the 2019 Plan, options were granted at an exercise price no less than fair value of the Company’s common stock on the grant date, except in certain cases related to employees outside of the U.S. Option awards granted typically had 10-year terms measured from the option grant date. While no shares are available for future issuance under the 2019 Plan, it continues to govern outstanding equity awards granted thereunder.

The compensation committee of the Company’s board of directors adopted and the Company’s stockholders approved the 2021 Equity Incentive Plan (the 2021 Plan) and the 2021 Employee Stock Purchase Plan (the ESPP), which became effective in August 2021. The 2021 Plan provides for the grant of incentive stock options, non-statutory stock options, restricted stock awards, restricted stock units (RSUs), stock appreciation rights and other stock-based awards. The Company’s employees, officers, directors and consultants are eligible to receive awards under the 2021 Plan. Under the terms of the 2021 Plan, options are granted at an exercise price no less than fair value of the Company’s common stock on the grant date, except in certain cases related to significant corporate transactions. Option awards granted typically have 10-year terms measured from the option grant date. As of March 31, 2025, the total number of shares authorized for issuance under the 2021 Plan was 10,148,121. Any shares that are returned under the 2019 Plan as a result of cancellation or forfeiture become available under the 2021 Plan. Further, the number of shares of common stock reserved for issuance under the 2021 Plan automatically increases on January 1 of each year, beginning on January 1, 2022, and continuing through and including January 1, 2031, by 5% of the total number of shares of common stock outstanding on December 31 of the immediately preceding calendar year, or a lesser number of shares determined by the Company’s board of directors prior to the applicable January 1st.

The ESPP allows employees, including executive officers, to contribute up to 15% of their earnings, subject to certain limitations, for the purchase of the Company’s common stock at a price per share equal to the lower of (a) 85% of the fair market value of a share of common stock on the first day of the offering period, or (b) 85% of the fair market value of a share of common stock on the last day of the offering period. As of March 31, 2025, there were 2,132,339 shares of common stock reserved for future issuance under the ESPP. The number of shares of common stock reserved for issuance under the ESPP will automatically increase on January 1 of each calendar year, beginning on January 1, 2022 and continuing through and including January 1, 2031, by the lesser of (1) 1% of the total number of shares of the Company’s common stock outstanding on December 31 of the preceding calendar year or (2) a number of shares determined by the Company’s board of directors. Shares subject to purchase rights granted under the ESPP that terminate without having been exercised in full will not reduce the number of shares available for issuance under the ESPP.

In March 2025, the Company’s board of directors adopted the 2025 Inducement Plan (the Inducement Plan), pursuant to which the Company may grant nonstatutory stock options, stock appreciation rights, restricted stock, RSUs and other stock-based awards with respect to an aggregate of 1,250,000 shares of its common stock. Awards under the Inducement Plan may only be granted to new employees who were not previously an employee or director of the Company or are commencing employment with the Company following a bona fide period of non-employment, in either case, as an inducement material to the individual’s entering into employment with the Company in accordance with the requirements of Nasdaq Stock Market Rule 5635(c)(4). The plan was not adopted by the Company’s stockholders and will be administered by the Company’s board of directors.

Awards with vesting conditions under all three plans typically vest 25% on the first anniversary of the grant date with the remainder vesting monthly over the following three years.

The activity for stock options is as follows:


						Weighted
						Average
				Weighted		Remaining		Aggregate
				Average		Contract		Intrinsic
	Options			Exercise		Terms		Values
	Outstanding			Price		(in years)		(in thousands)
Balance as of December 31, 2024		2,817,751		$	6.49		6.87	$	19
Options granted		3,009,196			1.80
Options expired		(40,000	)		7.87
Options forfeited		(225,000	)		7.58
Balance as of March 31, 2025		5,561,947		$	3.90		8.60	$	—
Vested and expected to vest, March 31, 2025		5,561,947		$	3.90		8.60	$	—
Options exercisable as of March 31, 2025		804,776		$	5.86		2.50	$	—

The aggregate intrinsic value disclosed in the above table is based on the difference between the exercise price of the stock option and the fair value of the Company’s common stock as of the respective period-end dates. The weighted-average grant-date fair value of stock options granted during the three months ended March 31, 2025 was $1.50 per share. There were no grants for the three months ended March 31, 2024.

The Black-Scholes option pricing model for employee and nonemployee stock options incorporates the following assumptions:

The Company has granted: (i) RSUs that vest quarterly over a two and a half year period or vest 25% annually over a four year period and (ii) RSUs with performance-based vesting conditions.

Upon the closing of the Acquisition, the Company granted a total of 803,000 RSUs to certain consultants. Of these RSUs, 401,500 are subject to service conditions, with 50% of such RSUs vesting on January 1, 2025, 25% of such RSUs vesting on March 27, 2025 and the remaining 25% of such RSUs vesting on June 27, 2025. The remaining 401,500 RSUs will vest subject to the satisfaction of performance conditions, including the achievement of specific operational milestones before September 30, 2025 (Performance-Based RSUs). For the Performance-Based RSUs, no stock-based compensation expense has been recognized because the vesting conditions are not probable of being achieved.

The activity for RSUs is as follows:


				Weighted-Average Grant-Date Fair
	Number of Shares			Value
Unvested at December 31, 2024		1,228,876		$	7.17
Vested		(320,333	)		7.28
Unvested at March 31, 2025		908,543		$	7.13

The fair value of restricted stock awards and RSUs vested during the three months ended March 31, 2025 and 2024 was approximately $0.5 million and $0.1 million, respectively.

The following table sets forth stock-based compensation expense for stock options, restricted stock awards, and RSUs included in the Company’s condensed consolidated statements of operations and comprehensive loss (in thousands):


	Three Months Ended March 31,
	2025		2024
Research and development expense	$	906	$	269
General and administrative expense		1,116		196
Total stock-based compensation expense	$	2,022	$	465

As of March 31, 2025, there was $12.0 million of total unrecognized compensation cost related to unvested stock options, which is expected to be recognized over a weighted average period of 3.4 years. Further, there was $2.8 million of unrecognized compensation cost related to unvested RSUs, which is expected to be recognized over a weighted average period of 2.5 years.