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Equity (Tables) | 12 Months Ended
--- | ---
Dec. 31, 2024
Schedule of initial carrying value | ​
​ | ​ | ​
(in thousands) | ​ | Allocated Amount
Common Stock | $ | 2,391
Public Warrants | ​ | 1,831
​ | $ | 4,222
​ | ​ | ​
​
​ | ​ | ​
(in thousands) | ​ | Allocated Amount
Common Stock | $ | 865
Private Pre-Funded Warrants | ​ | 1,214
Private Warrants | ​ | 2,389
​ | $ | 4,468
​ | ​ | ​
​
​ | ​ | ​
(in thousands) | ​ | Allocated Amount
Common Stock | $ | 1,447
Participation Right Pre-Funded Warrants | ​ | 580
Participation Right Private Warrants | ​ | 2,250
​ | $ | 4,277
​ | ​ | ​
Schedule of public warrants and underwriter warrants | ​
​ | ​ | ​
Stock price | $ | 0.79
Expected volatility | ​ | 108.01%
Contractual/expected term (in years) | ​ | 5.00
Risk-free interest rate | ​ | 4.64%
Expected dividend yield | ​ | 0%
​
​ | ​ | ​
Stock price | $ | 0.79
Expected volatility | ​ | 108.01%
Contractual/expected term (in years) | ​ | 5.00
Risk-free interest rate | ​ | 4.64%
Expected dividend yield | ​ | 0%
​
​ | ​ | ​
Stock price | $ | 0.65
Expected volatility | ​ | 108.01%
Contractual/expected term (in years) | ​ | 5.00
Risk-free interest rate | ​ | 4.25%
Expected dividend yield | ​ | 0%
Summary of warrants outstanding | ​
​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​
​ | ​ | Warrants | ​ | Pre-Funded Warrants(1)
(in thousands, except per share data) | ​ | Number | ​ | Wtd. Avg. Exercise Price | ​ | Wtd. Avg. Remaining Life (in years) | ​ | Number | ​ | Wtd. Avg. Exercise Price
Beginning Balance | ​ | — | ​ | — | ​ | — | ​ | — | ​ | —
Granted | ​ | 21,319 | $ | 1.0535 | ​ | ​ | ​ | 4,499 | $ | 0.0001
Exercised | ​ | (24) | ​ | 1.0500 | ​ | ​ | ​ | — | ​ | —
Forfeited/Expired | ​ | — | ​ | — | ​ | ​ | ​ | — | ​ | —
Outstanding at Period End | ​ | 21,295 | $ | 1.0535 | ​ | 4.74 | ​ | 4,499 | $ | 0.0001
​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​
(1) Pre-Funded warrants have no expiration date and only expire when exercised in full.
Schedule of outstanding, reserved and authorized shares under share-based compensation plans | ​
​ | ​ | ​ | ​ | ​
​ | ​ | December 31, | ​ | December 31,
(in thousands) |  | 2024 |  | 2023
Outstanding options and restricted stock units |  | 3,316 |  | 3,430
Reserved but unissued shares under the Plan | ​ | 1,858 | ​ | 2,302
Reserved but unissued shares at end of period |  | 5,174 |  | 5,732
Schedule of stock option activity | ​
​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​
​ | ​ | December 31, | ​ | December 31,
​ | ​ | 2024 | ​ | 2023
(in thousands, except per share data) | ​ | Options to Purchase Common Stock | ​ | Weighted Average Exercise Price | ​ | Weighted Average Remaining Contractual Life (in years) | ​ | Aggregate Intrinsic Value | ​ | Options to Purchase Common Stock | ​ | Weighted Average Exercise Price | ​ | Weighted Average Remaining Contractual Life (in years) |  | Aggregate Intrinsic Value
Outstanding at beginning of year |  | 2,759 | ​ | $ | 2.07 |  | 5.38 | ​ | 180 |  | 2,779 | ​ | $ | 2.05 |  | 6.43 | ​ | —
Granted |  | — | ​ | $ | — |  | ​ | ​ | — |  | — | ​ | $ | — |  | ​ | ​ | —
Exercised |  | — | ​ | $ | — |  | ​ | ​ | — |  | (20) | ​ | $ | 0.54 |  | ​ | ​ | 20
Forfeited/Expired |  | (307) | ​ | $ | 2.25 |  | ​ | ​ | 18 |  | — | ​ | $ | — |  | ​ | ​ | —
Outstanding at end of period |  | 2,452 | ​ | $ | 2.04 |  | 4.92 | ​ | 496 |  | 2,759 | ​ | $ | 2.07 |  | 5.38 | ​ | 180
Exercisable at end of period |  | 1,872 | ​ | $ | 1.70 |  | 4.55 | ​ | 485 |  | 2,024 | ​ | $ | 1.71 |  | 4.87 | ​ | 171
Schedule of restricted stock unit activity | ​
​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​
​ | ​ | December 31, | ​ | December 31,
​ | ​ | 2024 | ​ | 2023
(in thousands, except per share data) | ​ | Number of Shares | ​ | Weighted Average Grant Date Fair Value | ​ | Weighted Average Contractual Life (in years) (1) | ​ | Number of Shares | ​ | Weighted Average Grant Date Fair Value | ​ | Weighted Average Remaining Contractual Life (in years) (1)
Nonvested at beginning of period |  | 671 | ​ | $ | 1.05 | ​ | 1.08 | ​ | 423 | ​ | $ | 1.49 | ​ | 0.02
Granted |  | 517 | ​ | $ | 0.97 | ​ | ​ | ​ | 617 | ​ | $ | 0.82 | ​ | ​
Vested |  | (323) | ​ | $ | 1.08 | ​ | ​ | ​ | (361) | ​ | $ | 1.18 | ​ | ​
Forfeited | ​ | — | ​ | $ | — | ​ | ​ | ​ | (8) | ​ | $ | 0.79 | ​ | ​
Nonvested at end of period |  | 865 | ​ | $ | 0.99 | ​ | 0.88 | ​ | 671 | ​ | $ | 1.05 | ​ | 1.08
​
| 1) | Weighted Average Contractual Life calculation excludes the number of director RSUs that vest upon one of four performance events (refer to discussion above for details).
Schedule of share-based compensation activity | ​
​ | ​ | ​ | ​ | ​ | ​ | ​
​ | ​ | December 31,
(in thousands) |  | 2024 |  | 2023
Reserved but unissued shares at beginning of period | ​ | ​ | 188 | ​ | ​ | 196
Increases in the number of authorized shares | ​ |  | 116 | ​ |  | 7
Grants | ​ |  | (40) | ​ |  | (15)
Reserved but unissued shares at end of period | ​ |  | 264 | ​ |  | 188
Restricted Stock Units |
Schedule of compensation expense | ​
​ | ​ | ​ | ​ | ​ | ​ | ​
​ | ​ | For the Year Ended
​ | ​ | December 31,
(in thousands, except per share data) | ​ | 2024 |  | 2023
Share-based compensation expense | ​ | $ | 397 | $ | 337 | ​
Weighted average value per share | ​ | $ | 1.27 | $ | 0.83 | ​
Equity Incentive Plan |
Schedule of awards to employees stock in lieu of cash payment for compensation | ​
​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​
​ | ​ | 2024 | ​ | 2023
(in thousands, except per share data) | ​ | Number of Shares |  | Fair Value | ​ | Weighted Average per Share | ​ | Number of Shares |  | Fair Value | ​ | Weighted Average per Share
Share-based compensation | ​ | 24 | ​ | $ | 27 | ​ | $ | 1.15 | ​ | — | ​ | $ | — | ​ | $ | —
Fair value of stock payments in accrued compensation | ​ | 307 | ​ | $ | 326 | ​ | $ | 1.06 | ​ | 296 | ​ | $ | 234 | ​ | $ | 0.79
Consultant Stock Plan |
Schedule of compensation expense | ​
​ | ​ | ​ | ​ | ​ | ​ | ​
​ | ​ | For the Year Ended
​ | ​ | December 31,
(in thousands, except per share data) |  | 2024 |  | 2023
Share-based compensation expense | ​ | $ | 29 | ​ | $ | 10
Weighted average value per share | ​ | $ | 0.75 | ​ | $ | 0.69
​
Non-Qualified Stock Option |
Schedule of stock option activity | ​
​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​
​ | ​ | December 31, | ​ | December 31,
​ | ​ | 2024 | ​ | 2023
(in thousands, except per share data) | ​ | Options to Purchase Common Stock | ​ | Weighted Average Exercise Price | ​ | Weighted Average Remaining Contractual Life (in years) | ​ | Aggregate Intrinsic Value | ​ | Options to Purchase Common Stock | ​ | Weighted Average Exercise Price | ​ | Weighted Average Remaining Contractual Life (in years) |  | Aggregate Intrinsic Value
Outstanding at beginning of year |  | 491 | ​ | $ | 1.53 |  | 4.04 | $ | 30 |  | 341 | ​ | $ | 1.80 |  | 6.01 | $ | —
Granted |  | — | ​ | $ | — |  | ​ | ​ | ​ |  | 300 | ​ | $ | 1.11 |  | ​ | ​ | ​
Exercised |  | — | ​ | $ | — |  | ​ | ​ | ​ |  | (50) | ​ | $ | 1.31 |  | ​ | ​ | ​
Forfeited/Expired |  | — | ​ | $ | — |  | ​ | ​ | ​ |  | (100) | ​ | $ | 1.31 |  | ​ | ​ | ​
Outstanding at end of period |  | 491 | ​ | $ | 1.53 |  | 3.04 | $ | 119 |  | 491 | ​ | $ | 1.53 |  | 4.04 | $ | 30
Exercisable at end of period |  | 441 | ​ | $ | 1.60 |  | 3.29 | $ | 93 |  | 391 | ​ | $ | 1.69 |  | 4.61 | $ | 10

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