v3.26.1
Note 5 - Stockholders' Equity (Deficit), Equity Incentive Plans, And Stock-Based Compensation (Tables)
3 Months Ended
Mar. 31, 2026
Notes Tables  
Common Stock, Capital Shares Reserved for Future Issuance [Table Text Block]

Shares underlying outstanding warrants

    19,075,842  

Shares reserved for future grants under the 2020 Equity Incentive Plan

    514,043  

Shares underlying outstanding stock options

    569,098  

Total common stock reserved for future issuance

    20,158,983  
Schedule of Share-Based Payment Award, Stock Options, Valuation Assumptions [Table Text Block]

Black-Scholes-Merton Inputs

               
   

March 31, 2026

   

March 31, 2025

 

Risk-free interest rate

    3.88 %     4.40 %

Expected term (in years)

    5.50       5.38  

Expected volatility

    131.00 %     110.00 %

Expected dividend yield

    — %     — %
Share-Based Payment Arrangement, Option, Activity [Table Text Block]
   

Number of

Options

Outstanding

   

Weighted

Average

Exercise

price per

share

   

Weighted

Average

Remaining

Contractual

Term in Years

   

Aggregate

Intrinsic

Value

 

Balance, December 31, 2025

    158,098     $ 68.80       8.22     $ —  

Granted

    411,000       1.87       —       —  

Balance, March 31, 2026

    569,098     $ 20.46       9.41     $ —  

Options vested and exercisable at March 31, 2026

    257,321     $ 39.09       8.89     $ —  
Share-Based Payment Arrangement, Expensed and Capitalized, Amount [Table Text Block]
   

Three Months Ended March 31,

 
   

2026

   

2025

 

Research and development

  $ 299,066     $ 313,862  

General and administrative

    285,373       605,257  

Total stock-based compensation expense

  $ 584,439     $ 919,119