v3.26.1
Note 8 - Stock-based Compensation
 3 Months Ended
Mar. 31, 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):

 

    March 31, 2026    

March 31, 2025

  

Research and development

   $ 64     $ 77  

Selling, general and administrative

     150       119  

Total

   $ 214     $ 196  

 

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

     250,630       0.81  

Vested

     (54,760 )     1.21  

Forfeited

     —       —  

Restricted stock units outstanding, March 31, 2026

     469,065     $ 0.80  

 

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 19,756 shares of common stock underlying vested RSUs that were withheld during the quarter ended March 31, 2026, 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

     1,450,600       0.81                  

Forfeited

     —       —                  

Expired

     (57,053 )     61.23                  

Exercised

     —       —                  

March 31, 2026

     4,004,024     $ 4.53       8.4     $ 118  

Vested and exercisable options— March 31, 2026

     1,141,689     $ 13.81       6.2     $ 2  

Vested and expected to vest— March 31, 2026

     4,004,024     $ 4.53       8.4     $ 118  

 

As of March 31, 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 3 years. As of March 31, 2026, there were 310,787 shares available for grant under the Company’s equity incentive plans and 166,039 shares available for grant under the Amended ESPP.