v3.26.1
Note 7 - Stockholder's Equity (Tables)
12 Months Ended
Dec. 31, 2025
Notes Tables  
Share-Based Payment Arrangement, Cost by Plan [Table Text Block]
  

For the year ended December 31,

 
  

2025

  

2024

 

Research and development

 $124  $269 

General and administrative

  541   967 

Total stock-based compensation expense

 $665  $1,236 
Schedule of Unvested Restricted Stock Units Roll Forward [Table Text Block]
  

Number of Units and Awards

  

Weighted Average Grant Date Fair Value

 

Unvested balance at December 31, 2023

  1,311  $197.19 

Granted

  235,000   2.46 

Vested

  (283)  85.50 

Unvested balance at December 31, 2024

  236,028  $3.44 

Forfeited

  (212)  171.94 

Vested

  (416)  85.50 

Unvested balance at December 31, 2025

  235,400  $3.19 
Share-Based Payment Arrangement, Option, Activity [Table Text Block]
  

Stock Options

  

Weighted Average Exercise Price

  

Weighted Average Remaining Contractual Term (in years)

  

Aggregate Intrinsic Value (in thousands)

 

Outstanding as of December 31, 2023

  22,474  $85.5000   9.50  $— 

Granted

  234,000   2.46   10.00  $— 

Outstanding as of December 31, 2024

  256,474  $9.74   9.62  $— 

Outstanding as of December 31, 2025

  256,474  $9.74   8.62  $— 

Expected to vest

  162,624  $5.84   8.68  $— 

Vested and Exercisable as of December 31, 2025

  93,850   16.48   8.52  $— 
Schedule of Share-Based Payment Award, Stock Options, Valuation Assumptions [Table Text Block]
  

For the Year Ended December 31,

 
  

2024

 

Risk-free interest rate

  3.6%

Expected dividend yield

  — 

Expected term in years

  5.6 

Expected volatility

  135.0%
Schedule of Stockholders' Equity Note, Warrants or Rights [Table Text Block]
  

Warrants

  

Weighted Average Exercise Price

  

Aggregate Intrinsic Value (in thousands)

 

Outstanding, December 31, 2023

  524,601  $32.42  $1 

Granted

  1,861,817  $6.23   — 

Exercised

  (910,218) $10.16   — 

Outstanding, December 31, 2024

  1,476,200  $8.64  $— 

Expired

  (703,459) $6.52   — 

Outstanding, December 31, 2025

  772,741  $10.56  $— 
Fair Value Measurement Inputs and Valuation Techniques [Table Text Block]
  

December 31,

  

December 31,

 
  

2025

  

2024

 

Stock price

 $0.68  $2.00 

Risk-free interest rate

  3.75%  4.27%

Expected dividend yield

  —   — 

Expected term in years

  1.78   2.80 

Expected volatility

  151%  155%
Warrant [Member]  
Notes Tables  
Fair Value Measurement Inputs and Valuation Techniques [Table Text Block]
  

January 2023

  

New Series A

  

New Series B

 
  

Warrants

  

Warrants

  

Warrants

 

Stock price

 $14.25  $14.25  $14.25 

Risk-free interest rate

  4.40%  4.02%  4.40%

Expected dividend yield

  —   —   — 

Expected term in years

  2.1   5.0   1.5 

Expected volatility

  185%  138%  187%
  

October 2022

  

November 2023

  

January 2024

  

Series C

  

Series D

  

Placement Agent

 
  

Warrants

  

Warrants

  

Warrants

  

Warrants

  

Warrants

  

Warrants

 

Stock price

 $4.76  $4.76  $4.76  $4.76  $4.76  $4.76 

Risk-free interest rate

  4.79%  4.64%  4.64%  4.64%  4.96%  4.64%

Expected dividend yield

  —   —   —   —   —   — 

Expected term in years

  3.4   4.5   4.7   5.0   1.5   5.0 

Expected volatility

  160%  148%  145%  141%  132%  141%