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Stockholders’ Equity - Narrative (Details) - USD ($) |  |  |  |  |  |  |  | 3 Months Ended | 9 Months Ended |  |  |  |  |
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Sep. 09, 2025 | Feb. 17, 2025 | Jan. 29, 2025 | Jun. 03, 2022 | May 19, 2022 | May 20, 2021 | Apr. 12, 2018 | Sep. 30, 2025 | Sep. 30, 2024 | Sep. 30, 2025 | Sep. 30, 2024 | Sep. 08, 2025 | Dec. 31, 2024 | Jun. 16, 2023 | Jan. 03, 2023 | May 09, 2022
Equity, Class of Treasury Stock [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Common stock, authorized (in shares) | 1,000,000,000 |  |  |  |  |  |  | 1,000,000,000 |  | 1,000,000,000 |  | 50,000,000 | 1,000,000,000 |  |  |
Common stock, par value (in dollars per share) |  |  |  |  |  |  |  | $ 0.0005 |  | $ 0.0005 |  |  | $ 0.0005 |  | $ 0.0005 |
Preferred stock, authorized (in shares) |  |  |  |  |  |  |  | 1,000,000 |  | 1,000,000 |  |  | 1,000,000 |  |  |
Preferred stock, par value (in dollars per share) |  |  |  |  |  |  |  | $ 0.0005 |  | $ 0.0005 |  |  | $ 0.0005 |  |  |
Preferred stock, issued (in shares) |  |  |  |  |  |  |  | 0 |  | 0 |  |  | 0 |  |  |
Dividends, common stock |  |  |  |  |  |  |  | $ 0 | $ 0 | $ 0 | $ 0 |  |  |  |  |
Issuance of common stock as commitment fee for future financing |  |  |  |  |  |  |  |  |  | $ 158,000 | 0 |  |  |  |  |
Stock options granted (in shares) |  |  |  |  |  |  |  |  |  | 1,850,000 |  |  |  |  |  |
Fair value of stock options granted |  |  |  |  |  |  |  |  |  | $ 372,000 |  |  |  |  |  |
Share price (in dollars per share) |  |  |  |  |  |  |  | $ 0.46 |  | $ 0.46 |  |  |  |  |  |
Warrants (in shares) |  |  |  |  |  |  |  | 7,050,000 |  | 7,050,000 |  |  |  |  |  |
Share-based compensation expense |  |  |  |  |  |  |  | $ 400,000 | 600,000 | $ 1,500,000 | 3,000,000.0 |  |  |  |  |
Share-based compensation, nonvested award, cost not yet recognized, amount |  |  |  |  |  |  |  | 3,300,000 |  | $ 3,300,000 |  |  |  |  |  |
Weighted average period (in years) |  |  |  |  |  |  |  |  |  | 2 years 10 months 24 days |  |  |  |  |  |
General and administration |  |  |  |  |  |  |  | $ 4,635,000 | $ 6,573,000 | $ 13,351,000 | 20,805,000 |  |  |  |  |
Equivir License Agreement |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Equity, Class of Treasury Stock [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
General and administration |  |  |  |  |  |  |  |  |  | $ 0 | $ 100,000 |  |  |  |  |
2025 Directors Plan |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Equity, Class of Treasury Stock [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Number of shares reserved for issuance (in shares) | 500,000 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Stock options granted (in shares) |  |  |  |  |  |  |  | 0 |  |  |  |  |  |  |  |
Number of shares authorized (in shares) |  |  |  |  |  |  |  | 600,000 |  | 600,000 |  |  |  |  |  |
2022 Directors Plan |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Equity, Class of Treasury Stock [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Number of shares reserved for issuance (in shares) |  |  |  |  | 300,000 |  |  |  |  |  |  |  |  |  |  |
Stock options granted (in shares) |  |  |  |  |  |  |  |  |  | 200,000 | 210,000 |  |  |  |  |
Shares reserved for future issuance (in shares) |  |  |  |  |  |  |  |  |  |  |  | 100,000 |  |  |  |
Amended 2022 Directors' Plan |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Equity, Class of Treasury Stock [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Increase in shares reserved for future issuance (in shares) |  |  |  |  |  |  |  |  |  |  |  |  |  | 150,000 |  |
Amended 2010 Directors' Plan |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Equity, Class of Treasury Stock [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Number of shares authorized (in shares) |  |  |  |  |  | 775,000 |  |  |  |  |  |  |  |  |  |
2025 Plan |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Equity, Class of Treasury Stock [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Number of shares reserved for issuance (in shares) | 3,000,000 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Stock options granted (in shares) |  |  |  |  |  |  |  | 726,715 |  |  |  |  |  |  |  |
Number of shares authorized (in shares) |  |  |  |  |  |  |  | 2,307,035 |  | 2,307,035 |  |  |  |  |  |
2022 Plan |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Equity, Class of Treasury Stock [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Stock options granted (in shares) |  |  |  |  |  |  |  |  |  | 423,285 | 1,080,000 |  |  |  |  |
Increase in shares reserved for future issuance (in shares) |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 1,000,000
Shares reserved for future issuance (in shares) |  |  |  |  |  |  |  | 33,750 |  | 33,750 |  |  |  |  |  |
Amended 2010 Plan |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Equity, Class of Treasury Stock [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Conversion shares (in shares) |  |  |  |  |  | 4,900,000 |  |  |  |  |  |  |  |  |  |
2018 Stock Incentive Plan | CEO Options |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Equity, Class of Treasury Stock [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Exercise price, lower range (in dollars per share) |  |  |  | $ 0.60 |  |  |  |  |  |  |  |  |  |  |  |
Chief Executive Officer | 2018 Stock Incentive Plan |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Equity, Class of Treasury Stock [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Stock options granted (in shares) |  |  |  |  |  |  | 2,300,000 |  |  |  |  |  |  |  |  |
Stock issued during period (in shares) |  |  |  |  |  |  | 2,300,000 |  |  |  |  |  |  |  |  |
Former Chief Operating Officer | Inducement Option Award |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Equity, Class of Treasury Stock [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Stock options granted (in shares) |  | 500,000 |  |  |  |  |  |  |  |  |  |  |  |  |  |
Exercise price, lower range (in dollars per share) |  | $ 0.60 |  |  |  |  |  |  |  |  |  |  |  |  |  |
Award expiration period (in years) |  | 7 years |  |  |  |  |  |  |  |  |  |  |  |  |  |
Former Chief Operating Officer | Inducement Option Award | Share-Based Payment Arrangement, Tranche One |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Equity, Class of Treasury Stock [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Options vesting percentage |  | 25.00% |  |  |  |  |  |  |  |  |  |  |  |  |  |
Keystone | Keystone ELOC Shares |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Equity, Class of Treasury Stock [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Number of shares of common stock sold (in shares) |  |  | 7,700,000 |  |  |  |  |  |  | 11,300,000 |  |  |  |  |  |
Issuance of common stock as commitment fee for future financing (in shares) |  |  | 352,176 |  |  |  |  |  |  |  |  |  |  |  |  |
Issuance of common stock as commitment fee for future financing |  |  | $ 158,000 |  |  |  |  |  |  |  |  |  |  |  |  |
Sale of stock, consideration received on transaction |  |  |  |  |  |  |  |  |  | $ 3,600,000 |  |  |  |  |  |
Payments for commissions and expenses |  |  |  |  |  |  |  |  |  | $ 275,000 |  |  |  |  |  |
Sale of stock, price per share (in dollars per share) |  |  |  |  |  |  |  | $ 0.29 |  | $ 0.29 |  |  |  |  |  |
Keystone | Keystone ELOC Shares | Treasury Stock |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Equity, Class of Treasury Stock [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Number of shares of common stock sold (in shares) |  |  |  |  |  |  |  |  |  | 4,200,000 |  |  |  |  |  |

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