Stock-Based Compensation

6 Months Ended

Jun. 30, 2025

Share-Based Payment Arrangement [Abstract]

Stock-based compensation

8. Stock-based compensation

In January 2021, the Company adopted the 2021 Equity Incentive Plan (“2021 Plan”). The 2021 Plan provides for the granting of incentive stock options, non-statutory stock options, restricted stock awards, restricted stock units, equity appreciation rights, performance awards, and other equity-based awards. The Company's employees, officers, independent directors, and other persons are eligible to receive awards under the 2021 Plan. The 2021 Plan provides for increases to the number of shares reserved for issuance thereunder each January 1 equal to 4% of the total shares of the Company's common stock outstanding as of immediately preceding December 31, unless a lesser amount is stipulated by the Company's Board of Directors, which resulted in an increase of 668,297 shares authorized to be issued under the 2021 Plan. As of June 30, 2025, 3,239,368 shares of the Company’s common stock were authorized to be issued under the 2021 Plan, of which 170,221 shares were available for future issuance.

The amount, terms of grants, and exercisability provisions are determined and set by the Company's Board of Directors or compensation committee. The Company measures employee stock-based awards at grant-date fair value and records compensation expense on a straight-line basis over the vesting period of the award. The Company has recorded stock-based compensation related to its options and RSU's in the unaudited accompanying statements of operations as follows:

	Three Months Ended June 30,				Six Months Ended June 30,
	2025		2024		2025		2024
General and administrative	$	677,926	$	373,919	$	1,373,319	$	641,357
Research and development		357,787		288,402		742,476		456,627
	$	1,035,713	$	662,321	$	2,115,795	$	1,097,984

Stock options

The Company has issued service-based stock options that generally have a contractual term of up to 10 years and may be exercisable in cash or as otherwise determined by the Board of Directors. Vesting generally occurs over a period of not greater than four years.

The following table summarizes the activity for the periods indicated (unaudited):

						Weighted
				Weighted average		average remaining		Aggregate
				exercise		contractual		intrinsic
	Options			price		term (years)		value
Outstanding at January 1, 2025		2,228,658		$	5.08		8.4
Granted		849,196		$	6.06
Exercised		(17,557	)	$	1.09			$	80,060
Forfeited		(96,502	)	$	4.28
Outstanding at June 30, 2025		2,963,795		$	5.41		7.9	$	2,564,043
Exercisable at June 30, 2025		1,471,943		$	4.65		9.0	$	2,176,571
Vested and expected to vest at June 30, 2025		2,963,795		$	5.41		7.9	$	2,564,043

As of June 30, 2025, the unrecognized compensation cost was $7.1 million, and will be recognized over an estimated weighted-average amortization period of 1.9 years.

The fair value of options is estimated using the Black-Scholes option pricing model, which takes into account inputs such as the exercise price, the estimated fair value of the underlying common stock at the grant date, expected term, estimated stock price volatility, risk-free interest rate, and dividend yield. The fair value of stock options granted during the period ended June 30, 2025 was determined using the methods and assumptions discussed below.

•The expected term of employee stock options with service-based vesting is determined using the “simplified” method, as prescribed in SEC’s Staff Accounting Bulletin (“SAB”) No. 107, whereby the expected term equals the arithmetic average of the vesting term and the original contractual term of the option due to the Company’s lack of sufficient historical data.

•The expected stock price volatility is based on historical volatility of comparable public entities within the Company’s industry, which were commensurate with the expected term assumption as described in SAB No. 107.

•The risk-free interest rate is based on the interest rate payable on U.S. Treasury securities in effect at the time of grant for a period that is commensurate with the expected term.

•The expected dividend yield is 0% because the Company has not historically paid, and does not expect, for the foreseeable future, to pay a dividend on its common stock.

The grant date fair value of each option grant for the six months ended June 30, 2025 and 2024 was estimated using the Black-Scholes option-pricing model using the following weighted-average assumptions (unaudited):

	Six Months Ended June 30,
	2025			2024
Risk-free interest rate		4.5	%		4.2	%
Expected term (years)	5.75				5.74
Expected volatility		96.82	%		106.20	%
Expected dividend yield		0.0	%		0.0	%