Segment Reporting - Schedule of Significant Expenses Provided to the CODM on a Regular Basis (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Segment, Reconciliation of Other Items from Segments to Consolidated [Line Items]
Revenue	$ 0	$ 0	$ 886
Less:
Share-based compensation	37,614	44,833	25,675
Net loss	155,203	208,018	338,790
Reconciliation of net loss
Adjustments and reconciling items	155,203	208,018	338,790
Net loss	155,203	208,018	338,790
Increase (decrease) in fair value of contingent value right liability	(29,800)	20,400	18,900
Related Party
Less:
Share-based compensation	1,000	15,600	11,500
Research and development, excluding compensation and stock-based compensation	10,500	25,500	37,100
Reportable Segment
Less:
Net loss	155,203	208,018	338,790
Reconciliation of net loss
Adjustments and reconciling items	155,203	208,018	338,790
Net loss	155,203	208,018	338,790
Reportable Segment | Operating Segments
Segment, Reconciliation of Other Items from Segments to Consolidated [Line Items]
Revenue	0	0	886
Less:
Compensation	34,794	21,780	22,590
Share-based compensation	37,614	44,833	25,675
Research and development, excluding compensation and stock-based compensation	132,490	127,491	65,282
Other segment items	(49,695)	13,914	226,129
Net loss	155,203	208,018	338,790
Reconciliation of net loss
Adjustments and reconciling items	155,203	208,018	338,790
Net loss	155,203	208,018	338,790
Reportable Segment | Adjustments and reconciling items
Less:
Net loss	0	0	0
Reconciliation of net loss
Adjustments and reconciling items	0	0	0
Net loss	$ 0	$ 0	$ 0