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 |
% |
|