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Income Taxes - Narrative (Details) - USD ($) | 12 Months Ended
--- | ---
Dec. 31, 2025 | Dec. 31, 2024
Income Tax [Line Items] |  |
Provision for income taxes | $ 0 | $ 0
Income taxes paid | $ 0 | $ 0
At statutory rate, Percent | 21.00% | 21.00%
Operating loss carryforwards, federal | $ 534,500,000 | $ 502,200,000
Operating loss carryforwards, state | 501,900,000 | 487,800,000
Increase in valuation allowance | 6,699,000 | 12,156,000
Legacy Millendo |  |
Income Tax [Line Items] |  |
Operating loss carryforwards, federal | 455,800 |
Research Tax Credit Carryforward | Domestic Tax Jurisdiction [Member] |  |
Income Tax [Line Items] |  |
Tax credit carryforwards | 14,700,000 | 14,100,000
Research Tax Credit Carryforward | State and Local Jurisdiction [Member] |  |
Income Tax [Line Items] |  |
Tax credit carryforwards | 4,400,000 | $ 4,100,000
Orphan Drug Credit |  |
Income Tax [Line Items] |  |
Tax credit carryforwards | 7,400,000 |
Not Subject to Expiration |  |
Income Tax [Line Items] |  |
Operating loss carryforwards, federal | 313,300,000 |
Not Subject to Expiration | Research Tax Credit Carryforward | State and Local Jurisdiction [Member] |  |
Income Tax [Line Items] |  |
Tax credit carryforwards | $ 3,300,000 |

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- Definition Amount before allocation of valuation allowances of deferred tax asset attributable to deductible domestic operating loss carryforwards. Excludes state and local operating loss carryforwards. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 740 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 6 -Publisher FASB -URI https://asc.fasb.org/1943274/2147482685/740-10-50-6 + Details
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- Definition Amount before allocation of valuation allowances of deferred tax asset attributable to deductible state and local operating loss carryforwards. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 740 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 6 -Publisher FASB -URI https://asc.fasb.org/1943274/2147482685/740-10-50-6 + Details
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