CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS AND COMPREHENSIVE LOSS - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2025	Sep. 30, 2024
Operating expenses:
Research and development	$ 141,169	$ 157,607	$ 513,120	$ 628,398
General and administrative	28,213	20,561	89,524	66,782
Total operating expenses	169,382	178,168	602,644	695,180
Loss from operations	(169,382)	(178,168)	(602,644)	(695,180)
Other (expense) income, net	(3,840)	17,805	10,468	36,288
Loss before provision (benefit) for income taxes	(173,222)	(160,363)	(592,176)	(658,892)
Provision (benefit) for income taxes	221	(59)	1,091	687
Net loss	$ (173,443)	$ (160,304)	$ (593,267)	$ (659,579)
Net loss per share — basic (in dollars per share)	$ (1.64)	$ (1.70)	$ (5.74)	$ (7.50)
Net loss per share — diluted (in dollars per share)	$ (1.64)	$ (1.70)	$ (5.74)	$ (7.50)
Weighted average common shares outstanding—basic (in shares)	105,815,038	94,372,159	103,391,267	87,936,923
Weighted average common shares outstanding—diluted (in shares)	105,815,038	94,372,159	103,391,267	87,936,923
Net loss	$ (173,443)	$ (160,304)	$ (593,267)	$ (659,579)
Other comprehensive income (loss), net of tax	39	218	(43)	205
Comprehensive loss	$ (173,404)	$ (160,086)	$ (593,310)	$ (659,374)