Segment Reporting - Schedule of Significant Expenses Provided to the CODM on a Regular Basis (Details) - USD ($) $ in Thousands		3 Months Ended						9 Months Ended
		Sep. 30, 2025	Jun. 30, 2025	Mar. 31, 2025	Sep. 30, 2024	Jun. 30, 2024	Mar. 31, 2024	Sep. 30, 2025	Sep. 30, 2024
Segment, Reconciliation of Other Items from Segments to Consolidated [Line Items]
Stock-based compensation					$ 13,100			$ 27,803	$ 35,617
Net loss		$ 11,183	$ 36,717	$ 44,773	69,028	$ 38,837	$ 43,857	92,673	151,722
Reconciliation of net loss
Adjustments and reconciling items		11,183	36,717	44,773	69,028	38,837	43,857	92,673	151,722
Net loss		11,183	$ 36,717	$ 44,773	69,028	$ 38,837	$ 43,857	92,673	151,722
Research and development	[1]	45,247			44,744			127,015	112,308
Gain recognized within operating expenses		0			0			10,000	0
(Decrease) increase in fair value of CVR liability		(40,400)			18,700			(42,200)	19,600
Related Party
Segment, Reconciliation of Other Items from Segments to Consolidated [Line Items]
Stock-based compensation		300			6,400			800	13,800
Related Party | Paragon and License Agreement
Reconciliation of net loss
Research and development		7,000			1,600			9,600	21,200
Reportable Segment
Segment, Reconciliation of Other Items from Segments to Consolidated [Line Items]
Net loss		11,183			69,028			92,673	151,722
Reconciliation of net loss
Adjustments and reconciling items		11,183			69,028			92,673	151,722
Net loss		11,183			69,028			92,673	151,722
Operating Segments | Reportable Segment
Segment, Reconciliation of Other Items from Segments to Consolidated [Line Items]
Compensation		9,397			5,960			24,507	15,015
Stock-based compensation		9,566			13,100			27,803	35,617
Research and development, excluding compensation and share-based compensation		34,769			32,920			99,069	85,831
Other segment items		(42,549)			17,048			(58,706)	15,259
Net loss		11,183			69,028			92,673	151,722
Reconciliation of net loss
Adjustments and reconciling items		11,183			69,028			92,673	151,722
Net loss		11,183			69,028			92,673	151,722
Adjustments and reconciling items | Reportable Segment
Segment, Reconciliation of Other Items from Segments to Consolidated [Line Items]
Net loss		0			0			0	0
Reconciliation of net loss
Adjustments and reconciling items		0			0			0	0
Net loss		$ 0			$ 0			$ 0	$ 0

[1] Includes $7.0 million and $9.6 million in related party expenses for the three and nine months ended September 30, 2025, respectively, and $7.7 million and $34.2 million related party expenses for the three and nine months ended September 30, 2024, respectively.