v3.25.2
Note 10 - Stock-based Compensation (Tables)
6 Months Ended
Jun. 30, 2025
Notes Tables  
Share-Based Payment Arrangement, Option, Activity [Table Text Block]
  

Number of

shares

  

Weighted

average
exercise

price

  

Weighted

average

remaining

contractual

life (in

years)

  

Aggregate

intrinsic

value (in

thousands)

 

Outstanding as of December 31, 2023

  264,983  $18.30   7.7  $75 

Options granted

            

Forfeited/Expire

  (143,150)         

Outstanding as of December 31, 2024

  121,833   22.36   7.0    

Options granted

  547,000   1.84   10.0     

Forfeited/Expire

  (5,380)         

Outstanding as of June 30, 2025

  663,453   5.54   9.3    

Options vested and exercisable as of June 30, 2025

  119,281  $22.52   6.6  $ 
Nonvested Restricted Stock Shares Activity [Table Text Block]
  

Awards

  

Weighted

Average Grant

Date Fair

Value

 

Balance as of December 31, 2023 (unvested)

  124,166  $5.20 

Granted

       

Vested

  (90,833) $4.64 

Forfeited

  (33,333) $5.20 

Balance as of December 31, 2024 (unvested)

      

Granted

    $ 

Vested

    $ 

Forfeited

    $ 

Balance as of June 30, 2025 (unvested)

      
Share-Based Payment Arrangement, Expensed and Capitalized, Amount [Table Text Block]
  

Three months ended

June 30,

  

Six months ended

June 30,

 
  

2025

  

2024

  

2025

  

2024

 
  

(Unaudited)

 

Stock-based compensation expense

                

General and administrative

 $55  $72  $67  $283 

Research and development

  12   25   12   56 

Total stock-based compensation expense

 $67  $97  $79  $339