v3.26.1
Stock-Based Compensation (Tables)
12 Months Ended
Dec. 31, 2025
Share-Based Payment Arrangement [Abstract]  
Summary of Stock Option Activity

A summary of stock option activity is presented below (in thousands, except per share and contractual life data).


                Weighted  
          Weighted     Average  
          Average     Remaining  
          Exercise     Contractual  
    Number of     Price     Life  
    Shares     Per Share     (in Years)  
Options outstanding at December 31, 2023     6,091     $ 2.60       6.96   
Granted     1,093     $ 1.57          
Exercised       $          
Forfeited or expired     (375 )   $ 1.19          
Options outstanding at December 31, 2024     6,809     $ 2.52       6.55   
Granted     1,881     $ 1.14          
Exercised       $          
Forfeited or expired     (324 )   $ 1.78          
Options outstanding, vested and expected to vest as of December 31, 2025     8,366     $ 2.23       6.09  
Options exercisable as of December 31, 2025     5,830     $ 2.65       4.95  
A summary of restricted stock activity and related information (in thousands, except per share data):

A summary of restricted stock activity and related information (in thousands, except per share data):


   

Number 

of Shares 

   

Weighted 

Average Grant 

Date Fair Value 

Per Share 

 
Outstanding as of December 31, 2024     695     $ 1.25  
Granted     293     $ 0.87  
Vested and released         $  
Forfeited and canceled     (188 )   $ 1.07  
Outstanding as of December 31, 2025     800     $ 1.15  
Stock-based Compensation Expense

The following table summarizes total stock-based compensation expense for stock options and RSUs, which is included in the statements of operations (in thousands).

 

    Year Ended December 31,  
    2025     2024  
Research and development   $ 833     $ 1,001  
General and administrative     651       609  
Total stock-based compensation expense   $ 1,484     $ 1,610  
Schedule of Share-Based Payment Award, Stock Options, Valuation Assumptions

The weighted-average grant-date fair value of options granted during the year ended December 31, 2025 and 2024 were $0.92 and $1.26, respectively. The assumptions used in the Black-Scholes model for stock options are as follows:


  2025   2024
Risk-free interest rate 3.81% to 4.39%   3.79% – 5.53%
Expected dividend yield %   %
Expected volatility 100%   100%
Expected term 5.25-6.08 years   5.04-6.08 years
Schedule of Share-Based Payment Award, Restricted Stock Units, Valuation Assumptions

The assumptions used to estimate the fair value of the performance-based restricted stock units granted during the years ended December 31, 2025 and 2024 and valued using a Monte Carlo simulation were as follows:


 

Year Ended December 31,


 

2025

 

2024


RSUs Granted

292,500

 

292,500


Valuation date stock price

$1.03

 

$1.81


Risk-free interest rate

3.99%

 

4.53%


Expected divided yield
0%
0%
Expected volatility 100%
100%
Simulation term 4 years
4 years