Stock-based compensation expense is included in the accompanying statements of operations and comprehensive loss and is allocated to operating expenses based on the function of the related employee. Total stock-based compensation expense for the years ended December 31, 2025 and 2024 was $2.8 million and $1.5 million, respectively. Of these amounts, $1.1 million and $0.6 million were recorded to research and development expenses and $1.7 million and $0.8 million were recorded to general and administrative expenses for the years ended December 31, 2025 and 2024, respectively.

The fair value of each option grant during the years ended December 31, 2025 and 2024, was estimated on the grant date using the Black-Scholes option pricing model with the following assumptions:


	Year Ended December 31
	2025			2024
Expected volatility	60	-	80%	60	-	70%
Dividend yield	0%			0%
Risk free interest rates	3.87	0	4.32%	3.99	0	4.46%
Expected term	6	-	7 years	6	-	7 years

Expected volatility – Since the Company does not have sufficient stock price history, the expected volatility is calculated based on the average volatility for a peer group of companies in the industry and a similar stage of development in which the Company does business.

Risk-free interest rates – The Company applies the risk-free interest rate based on the U.S. Treasury yield for the expected term of the option.

Expected term - For employee and non-employee stock options, the Company calculated the expected term as the average of the contractual term of the option and the vesting period.

The estimated fair value of the Company’s Common Stock was determined by the Company’s management and board of directors and considered valuation estimates from a qualified, independent third-party valuation firm.


(in thousands, except share and per share amounts)	Number of Shares Underlying Options	Weighted Average Exercise Price		Aggregate Intrinsic Value
Outstanding at January 1, 2024	1,569,972	$	1.25	$	5,596
Granted	483,594	2.18
Cancelled / Expired	(94,339)	2.09
Exercised	(443,778)	0.42
Outstanding at December 31, 2024	1,515,449	$	1.74	$	5,705
Granted	2,133,622	6.31
Cancelled / Expired	(61,536)	2.23
Exercised	(181,629)	0.94
Outstanding at December 31, 2025	3,405,906	$	4.64	$	19,279
Vested and expected to vest at December 31, 2025	3,405,906	$	4.64	$	19,279

The following table summarizes information concerning outstanding and exercisable stock options at December 31, 2025:


	Options	Weighted Average Exercise Price		Weighted Average Remaining Contractual Life (Years)
Outstanding at December 31, 2025	3,405,906	$	4.64	8.79
Exercisable at December 31, 2025	715,535	$	1.57	7.06

The aggregate intrinsic value of exercisable options at December 31, 2025 was $6.2 million. As of December 31, 2025, unrecognized compensation cost related to non-vested options was $13.4 million, and the weighted average period over which this amount is expected to be recognized is 2.8 years. The weighted average grant date fair value of stock options granted during the years ended December 31, 2025 and 2024 was $6.05 per share and $4.06 per share, respectively.