v3.26.1
Note 8 - Stock-based Compensation
 6 Months Ended
Jun. 30, 2026
Notes to Financial Statements  
Share-Based Payment Arrangement [Text Block]

8. Stock-Based Compensation

 

The Company recorded total stock-based compensation expense for stock options, restricted stock units, or RSUs, and the Amended and Restated 2011 Employee Stock Purchase Plan, or the Amended ESPP, as follows (in thousands):

 

    Three Months Ended
June 30,		    

Six Months Ended
June 30,

  
   

2026

    

2025

    

2026

    

2025

  

Research and development

   $ 71     $ 55     $ 135     $ 132  

Selling, general and administrative

     172       111       322       230  

Total

   $ 243     $ 166     $ 457     $ 362  

 

The following table summarizes restricted stock unit activity under the Company’s equity incentive plans:

 

           

Weighted

  
   

Number of

    

Average

  
   

Restricted

    

Grant Date

  
   

Stock Units

    

Fair Value

  

Restricted stock units outstanding, January 1, 2026

     273,195     $ 0.88  

Granted

     286,330       0.83  

Vested

     (106,716 )     0.95  

Forfeited

     —       —  

Restricted stock units outstanding, June 30, 2026

     452,809     $ 0.83  

 

Upon vesting, certain of the Company’s RSUs may be settled on a net-exercise basis to cover any required withholding tax with the remaining amount converted into an equivalent number of shares of common stock. There were 21,462 and 41,218 shares of common stock underlying vested RSUs that were withheld during the three and six months ended June 30, 2026, respectively, based on the value of the RSUs as determined by the Company’s closing stock price on the applicable vesting date.

 

The following table summarizes stock option activity under the Company’s equity incentive plans:

 

   

Number
of Stock Options
Outstanding

   

Weighted-
Average
Exercise
Price

   

Weighted-
Average
Remaining
Contractual
Life (Years)

   

Aggregate
Intrinsic
Value

 
                           

(in thousands)

  

January 1, 2026

     2,610,477     $ 7.84                  

Granted

     1,665,500       0.83                  

Forfeited

     —       —                  

Expired

     (60,053 )     61.04                  

Exercised

     —       —                  

June 30, 2026

     4,215,924     $ 4.31       8.2     $ 664  

Vested and exercisable options— June 30, 2026

     1,418,867     $ 11.14       6.4     $ 113  

Vested and expected to vest— June 30, 2026

     4,215,924     $ 4.31       8.2     $ 664  

 

As of June 30, 2026, total stock-based compensation expense related to unvested options to be recognized in future periods was $1.7 million which is expected to be recognized over a weighted-average period of 2.7 years. As of June 30, 2026, there were 4,063,187 shares available for grant under the Company’s equity incentive plans and 266,039 shares available for grant under the Amended ESPP.