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Investments and Fair Value Instruments (Tables) | 9 Months Ended
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Sep. 30, 2025
Investments And Fair Value Instruments [Abstract] |
Summary of Amortized Cost and Fair Value of Investment Securities Portfolio | The following tables summarize the amortized cost and fair value of the investment securities portfolio at December 31, 2024:
(Dollars in thousands) |  | Amortized Cost |  |  | Unrealized Gains |  |  | Unrealized Losses |  |  | Estimated Fair Value |
December 31, 2024 |  |  |  |  |  |  |  |  |  |  |  |
Cash equivalents: |  |  |  |  |  |  |  |  |  |  |  |
Money market funds |  | $ | 2,757 |  |  | $ | — |  |  | $ | — |  |  | $ | 2,757 |
Total Assets at Fair Value |  | $ | 2,757 |  |  | $ | — |  |  | $ | — |  |  | $ | 2,757 |
The Company did not have any investment categories that were in a continuous unrealized loss position for more than twelve months as of September 30, 2025.
Summary of Fair Value of Investment Securities | The fair value of the investment securities at September 30, 2025 and December 31, 2024 were as follows:
|  | Fair Value Measurements at September 30, 2025 |
(Dollars in thousands) |  | Level 1 |  |  | Level 2 |  |  | Level 3 |  |  | Total |
Assets at Fair Value |  |  |  |  |  |  |  |  |  |  |  |
Short-term investments: |  |  |  |  |  |  |  |  |  |  |  |
Corporate securities |  |  | 4,765 |  |  |  | — |  |  |  | — |  |  |  | 4,765 |
Total Assets at Fair Value |  | $ | 4,765 |  |  | $ | — |  |  | $ | — |  |  | $ | 4,765 |
|  | Fair Value Measurements at December 31, 2024 |
(Dollars in thousands) |  | Level 1 |  |  | Level 2 |  |  | Level 3 |  |  | Total |
Assets at Fair Value |  |  |  |  |  |  |  |  |  |  |  |
Cash equivalents: |  |  |  |  |  |  |  |  |  |  |  |
Money market funds |  | $ | 2,757 |  |  | $ | — |  |  | $ | — |  |  | $ | 2,757 |
Total Assets at Fair Value |  | $ | 2,757 |  |  | $ | — |  |  | $ | — |  |  | $ | 2,757 |
Summary of Preferred Investment Option Liabilities Measured and Recorded on Recurring Basis using Black-Scholes Model | The preferred investment option liabilities were measured and recorded on a recurring basis using the Black-Scholes Model with the following assumptions as of September 30, 2025 and December 31, 2024:
|  | March 2023 Options - Series A & March 2023 Placement Agent Options |  |  | August 2022 Options & August 2022 Placement Agent Options |
|  | September 30, 2025 |  |  | December 31, 2024 |  |  | September 30, 2025 |  |  | December 31, 2024 |
Remaining term (in years) |  |  | 2.39 |  |  |  | 3.14 |  |  |  | 1.92 |  |  |  | 2.67 |
Expected volatility |  |  | 90.5 | % |  |  | 101.7 | % |  |  | 94.3 | % |  |  | 95.9 | %
Risk-free interest rate |  |  | 3.6 | % |  |  | 4.3 | % |  |  | 3.6 | % |  |  | 4.3 | %
Expected dividend yield |  |  | — |  |  |  | — |  |  |  | — |  |  |  | — |
Summary of Changes in Fair Value and Other Adjustments of Assets and Liabilities | The following table sets forth the establishment of the Company’s Level 3 assets and liabilities, as well as a summary of the changes in the fair value and other adjustments (in thousands):
(Dollars in thousands) |  | March 2023 Options - Series A |  |  | March 2023 Placement Agent Options |  |  | August 2022 Options |  |  | August 2022 Placement Agent Options |  |  | Note Receivable Bifurcated Derivatives |  |  | Contingent Liabilities |  |  | Total |
Balance as of December 31, 2024 |  | $ | 2,285 |  |  | $ | 90 |  |  | $ | 349 |  |  | $ | 7 |  |  | $ | 250 |  |  | $ | 2,000 |  |  | $ | 4,981 |
Change in fair value |  |  | (1,570 | ) |  |  | (60 | ) |  |  | (239 | ) |  |  | (6 | ) |  |  | (250 | ) |  |  | (2,000 | ) |  |  | (4,125 | )
Balance as of September 30, 2025 |  | $ | 715 |  |  | $ | 30 |  |  | $ | 110 |  |  | $ | 1 |  |  | $ | — |  |  | $ | — |  |  | $ | 856 |

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- Definition Tabular disclosure of financial instrument measured at fair value on recurring or nonrecurring basis. Includes, but is not limited to, instrument classified in shareholders' equity. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 820 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 2 -Subparagraph (b) -Publisher FASB -URI https://asc.fasb.org/1943274/2147482106/820-10-50-2 Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 820 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 2 -Subparagraph (a) -Publisher FASB -URI https://asc.fasb.org/1943274/2147482106/820-10-50-2 Reference 3: http://www.xbrl.org/2003/role/exampleRef -Topic 820 -SubTopic 10 -Name Accounting Standards Codification -Section 55 -Paragraph 100 -Publisher FASB -URI https://asc.fasb.org/1943274/2147482078/820-10-55-100 Reference 4: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 820 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 3 -Subparagraph (a) -Publisher FASB -URI https://asc.fasb.org/1943274/2147482106/820-10-50-3 + Details
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- Definition Tabular disclosure of input and valuation technique used to measure fair value and change in valuation approach and technique for each separate class of asset and liability measured on recurring and nonrecurring basis. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 820 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 2 -Subparagraph (bbb)(1) -Publisher FASB -URI https://asc.fasb.org/1943274/2147482106/820-10-50-2 Reference 2: http://www.xbrl.org/2003/role/exampleRef -Topic 820 -SubTopic 10 -Name Accounting Standards Codification -Section 55 -Paragraph 103 -Publisher FASB -URI https://asc.fasb.org/1943274/2147482078/820-10-55-103 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Topic 820 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 2 -Subparagraph (bbb)(2) -Publisher FASB -URI https://asc.fasb.org/1943274/2147482106/820-10-50-2 + Details
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- Definition Tabular disclosure of the fair value measurement of liabilities using significant unobservable inputs (Level 3), a reconciliation of the beginning and ending balances, separately presenting changes attributable to the following: (1) total gains or losses for the period (realized and unrealized), segregating those gains or losses included in earnings (or changes in net assets), and gains or losses recognized in other comprehensive income (loss) and a description of where those gains or losses included in earnings (or changes in net assets) are reported in the statement of income (or activities); (2) purchases, sales, issues, and settlements (each type disclosed separately); and (3) transfers in and transfers out of Level 3 (for example, transfers due to changes in the observability of significant inputs) by class of liability. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 820 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 3 -Subparagraph (b) -Publisher FASB -URI https://asc.fasb.org/1943274/2147482106/820-10-50-3 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Topic 820 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 2 -Subparagraph (d) -Publisher FASB -URI https://asc.fasb.org/1943274/2147482106/820-10-50-2 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Topic 820 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 2 -Subparagraph (c) -Publisher FASB -URI https://asc.fasb.org/1943274/2147482106/820-10-50-2 + Details
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