v3.25.2
Equity Incentive Plan – Stock-Based Compensation Expense and Warrants (Tables)
6 Months Ended
Jun. 30, 2025
Share-Based Payment Arrangement [Abstract]  
Summary of Stock Option Award Activity

A summary of the stock option activity for the six months ended June 30, 2025 is as follows:

 

   Number of
Stock
Options
   Weighted-
Average
Exercise Price
   Weighted-
Average
Remaining
Contractual
Life
   Aggregate
Intrinsic
Value (in thousands)
 
Outstanding as of December 31, 2024   2,797,529   $1.84    7.82   $521 
Granted    1,028,576   $0.86    -   $- 
Exercised   (39,650)  $0.41    -   $- 
Forfeited   (16,910)  $1.97    -   $- 
Expired   (32,779)  $1.96    -   $- 
Outstanding as of June 30, 2025   3,736,766   $1.58    8.03   $989 
Exercisable as of June 30, 2025   1,837,384   $1.99    6.88   $415 
Vested and expected to vest as of June 30, 2025   3,736,766   $1.58    8.03   $989 

Summary of Weighted-Average Assumptions Used to Calculate Fair Value of Stock Options Granted

For the six months ended June 30, 2025 and 2024, the Company utilized the Black-Scholes option-pricing model for estimating the fair value of the stock option granted and records compensation expense on a straight-line basis over the vesting period of the awards. The Company estimated the fair value of each option grant on the grant date using the Black-Scholes option pricing model with the following weighted-average assumptions:

 

  

Six Months Ended June 30,

 
   2025   2024 
Expected volatility   115.1% – 121.3%   123.76% – 143.10%
Expected term (years)   6.02 10.00    6.02 10.00 
Risk-free interest rate   4.11% – 4.79%   4.03% – 4.30%
Dividend rate   %   %
Schedule of Stock-Based Compensation Expense Recognized

The following table summarizes the components of stock-based compensation expense recognized in the Company’s Condensed Statements of Operations (in thousands):

 

   2025   2024   2025   2024 
   Three Months Ended   Six Months Ended 
   June 30,   June 30, 
   2025   2024   2025   2024 
Research and development  $106   $81   $243   $207 
General and administrative   239    163    390    460 
Total stock-based compensation expense  $345   $244   $633   $667 
Schedule of Common Stock Warrant Activity

The following is a summary of the common stock warrants activity during the six months ended June 30, 2025.

 

   Shares
Issuable
Upon Exercise
of Outstanding
Warrants
   Weighted-
Average
Exercise
Price
   Weighted-
Average
Remaining
Contractual
Life
   Aggregate
Intrinsic
Value
(In thousands)
 
Outstanding as of December 31, 2024   25,558,845   $2.32    3.42   $59,298 
Issued in February 2025 to:                    
Underwriter   576,191   $1.21    4.61   $697 
Exercised   (976,752)  $0.03    -   $(25)
Expired   (9,000)  $1.01    -   $(9)
Outstanding as of June 30, 2025   25,149,284   $2.38    2.95   $59,961