The Company’s 2021 Stock Option and Grant Plan (the “2021 Plan”) provided for the Company to grant incentive stock options, non-qualified stock options, restricted stock awards, unrestricted stock awards and restricted stock units (collectively, the “Awards”) to among others, members of the board of directors, employees, consultants and other key persons to the Company and its affiliates. The 2021 Plan is administered by the board of directors, or at the discretion of the board of directors, by a committee of the board.

In October 2024, the Company completed its IPO, and in connection with the closing, the board of directors determined that no further awards would be granted under the 2021 Plan and any remaining options available for grant would cease to be available. Awards outstanding under the 2021 Plan will continue to be governed by their existing terms. Shares of unused common stock underlying any awards that are forfeited, canceled or reacquired by the Company prior to vesting will again be available for the grant of awards under the 2024 Plan.

On August 19, 2024, the Company’s board of directors adopted, and on October 4, 2024 its stockholders approved, the 2024 Stock Option and Incentive Plan (the “2024 Plan”), which became effective upon the date immediately preceding the date on which the IPO registration statement was declared effective by the SEC. The 2024 Plan allows the Company to make equity-based and cash-based incentive awards to its officers, employees, directors, and consultants. The 2024 Plan provides for the grant of incentive stock options, non-qualified stock options, stock appreciation rights, restricted stock units, restricted shares of common stock and other stock-based awards. The number of shares reserved under the 2024 Plan is subject to adjustment in the event of a stock split, stock dividend or other change in the Company’s capitalization. In addition, the number of shares reserved and available for issuance under the 2024 Plan will automatically increase on January 1, 2025 and each January 1 thereafter, by five percent of the outstanding number of shares of its common stock on the immediately preceding December 31 or such lesser number of shares as determined by the Company’s compensation committee. On January 1, 2025, the number of shares of common stock that may be issued under the 2024 Plan increased by 2,680,169 shares of common stock.

The shares of common stock underlying any awards under the 2024 Plan and the 2021 Plan that are forfeited, cancelled, held back upon exercise or settlement of an award to satisfy the exercise price or tax withholding, reacquired by the Company prior to vesting, satisfied without the issuance of stock, expire or are otherwise terminated (other than by exercise) will be added back to the shares of common stock available for issuance under the 2024 Plan.

As of December 31, 2024, the Company had a total of 9,411,177 shares of common stock reserved under the 2024 Plan and the 2021 Plan, and 2,920,606 shares available for future issuance under the 2024 Plan.

On August 19, 2024, the Company’s board of directors adopted, and on October 4, 2024 its stockholders approved, the 2024 Employee Stock Purchase Plan (the “2024 ESPP”), which became effective on the date immediately preceding the date on which the IPO registration statement was declared effective by the SEC. The 2024 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) 976,934 shares of common stock, (ii) one percent of the outstanding number of shares of common stock on the immediately preceding December 31, or (iii) such lesser number of shares of common stock as determined by the administrator of the 2024 ESPP. The number of shares reserved under the 2024 ESPP is subject to adjustment in the event of a stock split, stock dividend or other change in the Company’s capitalization. On January 1, 2025, there was no increase to the number of shares of common stock that may be issued under the 2024 ESPP Plan.

As of December 31, 2024, the Company had 488,467 shares available for issuance under the 2024 ESPP and no shares had been issued under the 2024 ESPP.

The fair value of stock option grants is estimated using the Black-Scholes option-pricing model. The Company historically has been a private company and lacks company-specific historical and implied volatility information. Therefore, it estimates its expected stock volatility based on the historical volatility of a publicly traded set of peer companies and expects to continue to do so until such time as it has adequate historical data regarding the volatility of its own traded stock price. The expected option term is calculated based on the simplified method for awards with service-based conditions, which uses the midpoint between the vesting date and the contractual term, as the Company does not have sufficient historical data to develop an estimate based on participant behavior. The risk-free interest rate is determined by reference to the U.S. Treasury yield curve in effect at the time of grant of the award for time periods approximately equal to the expected term of the award. Expected dividend yield is based on the fact that the Company has never paid cash dividends and does not expect to pay any cash dividends in the foreseeable future.

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


	Year Ended December 31,
	2024			2023
Per share fair value of common stock	$	7.12		$	4.52
Expected volatility		79.1	%		77.0	%
Expected dividends		0	%		0	%
Expected term (in years)		6.2			6.3
Risk-free rate		3.41	%		1.94	%

The Company generally grants stock-based awards with service-based vesting. During the year ended December 31, 2024, the Company granted performance-based stock options to certain employees and directors for the purchase of an aggregate 1,206,249 shares of common stock with a vesting commencement date contingent upon the achievement of the Series B Option closing, which was achieved in April 2024. The Company determined that it met all the conditions to establish a grant date for these performance-based stock options at the original issuance date and that the performance condition was deemed probable of achievement, as the board of directors had approved the Series B Option closing prior to the grant date. The vesting of the performance-based stock options is also subject to the grantees’ continued service until the fourth anniversary of the Series B Option closing.

The following table summarizes the activity of stock options with service-based and performance-based vesting conditions during the year ended December 31, 2024:


	Number of Options			Weighted- Average Exercise Price		Weighted- Average Remaining Contractual Term (Years)		Intrinsic Value (in thousands)
Outstanding as of December 31, 2023		4,166,107		$	3.75		8.5	$	4,648
Granted		3,472,281			7.12
Exercised		(39,770	)		4.01
Forfeited		(1,104,280	)		3.82
Expired		(3,767	)		4.01
Outstanding as of December 31, 2024		6,490,571		$	5.54		7.9	$	71,266
Options exercisable December 31, 2024		1,993,278		$	3.64		5.3	$	25,507
Vested and expected to vest December 31, 2024		6,490,571		$	5.54		7.9	$	71,266

The aggregate intrinsic value 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. The aggregate intrinsic value of stock options exercised during the years ended December 31, 2024 and 2023 was $0.3 million and less than $0.1 million, respectively.

The weighted-average grant-date fair value of options granted during the years ended December 31, 2024 and 2023 was $5.10 and $3.08, respectively.

As of December 31, 2024, there was $15.6 million of total unrecognized compensation cost related to unvested stock options, which is expected to be recognized over a weighted-average period of 2.9 years.

In February 2024, the Company entered into a separation agreement with the Company’s former Chief Operating Officer (“COO”), effective March 2024. Under the terms of the separation agreement, stock options for the purchase of 142,935 shares of common stock, representing all of the vested options held by the former COO as of the date of her termination, became exercisable for one year following her termination.

In March 2024, the Company entered into a separation agreement with the Company’s former Chief Executive Officer (“CEO”), effective March 2024. Under the terms of the separation agreement, vesting of options for the purchase of 38,245 shares of common stock held by the former CEO were accelerated with no change to the exercise price of such options. In addition, stock options for the purchase of 532,553 shares of common stock, representing all of the vested options held by the former CEO as of the date of her termination, became exercisable for two years following her termination.

As a result of these modifications, the Company recognized $0.7 million of incremental stock-based compensation during the year ended December 31, 2024.

The following table illustrates the classification of stock-based compensation in the consolidated statements of operations and comprehensive loss (in thousands):


	Year Ended December 31,
	2024		2023
General and administrative (1)	$	4,842	$	2,354
Research and development		1,162		1,073
	$	6,004	$	3,427

(1) Includes related party amounts of $0.1 million for the year ended December 31, 2023 (Note 16)