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Commitments and Contingencies (Details Textual) € in Millions |  | 1 Months Ended | 6 Months Ended | 12 Months Ended |  |
--- | --- | --- | --- | --- | --- | ---
Nov. 30, 2023 | Mar. 31, 2024 | Jul. 31, 2021 EUR (€) | Jun. 30, 2021 ft² | Jun. 30, 2024 USD ($) | Jun. 30, 2023 USD ($) | Dec. 31, 2023 USD ($) | Dec. 31, 2022 USD ($) | Aug. 29, 2020 ft²
Commitments And Contingencies [Line Items] |  |  |  |  |  |  |  |  |
Amount of retention bonuses |  |  |  |  | $ 444,000 |  |  |  |
Percentage of retention bonuses | 50.00% |  |  |  |  |  |  |  |
Retention bonus paid |  |  |  |  |  |  | $ 86,000 |  |
Restructuring Reserve, Current |  |  |  |  |  |  | 0 |  |
Severance expense |  |  |  |  |  |  | $ 159,000 |  |
Area of office facilities taken on lease | ft² |  |  |  |  |  |  |  |  | 5,200
Operating lease term |  |  |  |  |  |  |  |  | 42 months
Additional operating lease term |  | 6 months |  |  |  |  |  |  |
Lease renewal option |  |  |  |  | extend the lease term six (6) months through September 2024 |  |  |  |
Operating lease extended expiry |  | 2024-09 |  |  |  |  |  |  |
Percentage of base rent to be paid monthly |  |  |  |  | 125.00% |  |  |  |
Lessee, Operating Lease, Existence of Option to Extend [true false] |  | true |  |  |  |  |  |  |
Area of additional office facilities taken on sublease | ft² |  |  |  | 3,000 |  |  |  |  |
Operating sublease term |  |  |  | 29 months |  |  |  |  |
Lessee, operating lease, assumptions and judgments, allocation of lease and nonlease component |  |  |  |  | The leases include real estate taxes and insurance, which is not a lease component and is not included in the lease obligation. In addition, common area maintenance charges are based on actual costs incurred and are a non-lease component that is not included in the lease obligation. |  |  |  |
Operating lease, cash paid for measurement of lease liabilities |  |  |  |  | $ 47,000 | $ 67,000 |  |  |
Lease liability |  |  |  |  | $ 24,000 |  |  |  |
Operating Lease, Liability, Current, Statement of Financial Position [Extensible Enumeration] |  |  |  |  | Accrued expenses and other liabilities |  |  |  |
Weighted-average remaining lease term |  |  |  |  | 3 months 18 days |  |  |  |
Weighted-average discount rate |  |  |  |  | 7.00% |  |  |  |
General and Administrative Expense |  |  |  |  |  |  |  |  |
Commitments And Contingencies [Line Items] |  |  |  |  |  |  |  |  |
Rent expense |  |  |  |  | $ 31,000 | $ 63,000 |  |  |
Research and development | Patent Assignment Agreement | University Medical Center of Johannes Gutenberg University Mainz |  |  |  |  |  |  |  |  |
Commitments And Contingencies [Line Items] |  |  |  |  |  |  |  |  |
Potential upfront and milestone obligations and royalty obligations | € |  |  | € 1.6 |  |  |  |  |  |
Clinical development decisions |  |  |  |  |  |  |  |  |
Commitments And Contingencies [Line Items] |  |  |  |  |  |  |  |  |
Amount of retention bonuses |  |  |  |  |  |  |  | $ 265,000 |

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