Segment Reporting - Schedule of Disaggregation of Income Statement Expenses (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Segment Reporting Information [Line Items]
Research and development	$ 476,644	$ 332,341	$ 169,451
Acquired manufacturing rights (Note 7)	0	75,000	22,995
General and administrative	92,902	60,700	39,810
Total operating expenses	569,546	468,041	232,256
Total other income, net	105,619	65,775	8,771
Net loss	463,927	402,266	223,485
Reportable Segment
Segment Reporting Information [Line Items]
Acquired manufacturing rights (Note 7)	0	75,000	22,995
General and administrative	92,902	60,700	39,810
Total operating expenses	569,546	468,041	232,256
Total other income, net	105,619	65,775	8,771
Net loss	463,927	402,266	223,485
Research and development - external costs | Reportable Segment
Segment Reporting Information [Line Items]
Research and development	349,510	261,984	132,418
Research and development - internal costs | Reportable Segment
Segment Reporting Information [Line Items]
Research and development	$ 127,134	$ 70,357	$ 37,033