Accrued Expenses and Other Current Liabilities - Components of Accrued Expenses and Other Current Liabilities (Details) - USD ($) $ in Thousands	Jun. 30, 2026	Dec. 31, 2025
Accrued Expenses and Other Current Liabilities [Line Items]
Total accrued expenses and other current liabilities	$ 33,528	$ 24,207
Location, Statement of Financial Position, Balance [Axis]: ck0001991792:ExternalResearchAndDevelopmentExpenses
Accrued Expenses and Other Current Liabilities [Line Items]
Total accrued expenses and other current liabilities	24,927	13,936
Location, Statement of Financial Position, Balance [Axis]: ck0001991792:PersonnelRelatedExpenses
Accrued Expenses and Other Current Liabilities [Line Items]
Total accrued expenses and other current liabilities	5,576	8,216
Location, Statement of Financial Position, Balance [Axis]: us-gaap:AccruedProfessionalFeesCurrent
Accrued Expenses and Other Current Liabilities [Line Items]
Total accrued expenses and other current liabilities	1,347	967
Location, Statement of Financial Position, Balance [Axis]: us-gaap:DeferredRevenueCurrent
Accrued Expenses and Other Current Liabilities [Line Items]
Total accrued expenses and other current liabilities	226	286
Location, Statement of Financial Position, Balance [Axis]: us-gaap:OtherAssetsCurrent
Accrued Expenses and Other Current Liabilities [Line Items]
Total accrued expenses and other current liabilities	$ 1,452	$ 802