Segment Information - Schedule of Segment Information (Details) - USD ($) $ in Thousands	3 Months Ended				6 Months Ended
	Jun. 30, 2025	Mar. 31, 2025	Jun. 30, 2024	Mar. 31, 2024	Jun. 30, 2025	Jun. 30, 2024
Segment Reporting Information [Line Items]
Product revenue, net	$ 212,802		$ 14,638		$ 350,052	$ 14,638
Cost of sales	(9,065)		(636)		(13,578)	(636)
Selling, general and administrative	(196,858)		(105,448)		(364,734)	(186,249)
Net loss	(42,281)	$ (73,238)	(151,971)	$ (147,541)	(115,519)	(299,512)
Reportable Segment
Segment Reporting Information [Line Items]
Product revenue, net	212,802		14,638		350,052	14,638
Cost of sales	(9,065)		(636)		(13,578)	(636)
Research and development - personnel and internal expense	(15,002)		(17,295)		(30,024)	(34,011)
Research and development - external expense	(39,079)		(53,796)		(68,229)	(108,317)
Selling, general and administrative	(196,858)		(105,448)		(364,734)	(186,249)
Other segment income (expense)	4,921		10,566		10,994	15,063
Net loss	$ (42,281)		$ (151,971)		$ (115,519)	$ (299,512)