Segment Information - Significant expense categories that are regularly reported to the chief operating decision maker (Details) - Reportable Segment [Member] - USD ($) $ in Thousands		3 Months Ended		6 Months Ended
		Jun. 30, 2025	Jun. 30, 2024	Jun. 30, 2025	Jun. 30, 2024
Segment Reporting Information [Line Items]
Revenue		$ 221	$ 0	$ 451	$ 0
Net loss before noncontrolling interest		(36,965)	(38,466)	(74,917)	(73,799)
Clinical trial expense
Segment Reporting Information [Line Items]
Net loss before noncontrolling interest		(7,188)	(10,619)	(14,711)	(18,927)
Cash compensation
Segment Reporting Information [Line Items]
Net loss before noncontrolling interest		(13,811)	(11,059)	(27,064)	(21,669)
Cash operating expenses
Segment Reporting Information [Line Items]
Net loss before noncontrolling interest		(11,595)	(12,325)	(24,739)	(24,701)
Other segment items
Segment Reporting Information [Line Items]
Net loss before noncontrolling interest	[1]	$ (4,592)	$ (4,463)	$ (8,854)	$ (8,502)

[1] Other segment items primarily include interest income, equity-based compensation and depreciation.