Segment Information - Schedule of Segment Information (Detail) - USD ($) $ in Thousands	3 Months Ended				6 Months Ended
	Jun. 30, 2026	Mar. 31, 2026	Jun. 30, 2025	Mar. 31, 2025	Jun. 30, 2026	Jun. 30, 2025
Segment Reporting Information [Line Items]
Operating Expenses	$ 102,638		$ 75,582		$ 206,245	$ 150,515
Interest income	(7,461)		(2,373)		(15,069)	(5,325)
Interest expense	1,217		314		2,430	314
Other expense (income), net	11		6		151	11
Segment net loss and consolidated net loss	96,405	$ 97,352	73,529	$ 71,986	193,757	145,515
Late-stage Development [Member]
Segment Reporting Information [Line Items]
Operating Expenses	25,593		27,115		53,695	55,212
Early-stage, Preclinical and Discovery Programs [Member]
Segment Reporting Information [Line Items]
Operating Expenses	11,791		10,039		25,766	19,817
R&D Personnel Related [Member]
Segment Reporting Information [Line Items]
Operating Expenses	17,600		14,568		35,647	29,442
Research and Development Software, Facilities and Other Strategic Support [Member]
Segment Reporting Information [Line Items]
Operating Expenses	6,537		4,907		12,271	9,332
Other Operational Infrastructure and Advisory Support [Member]
Segment Reporting Information [Line Items]
Operating Expenses	23,269		8,582		43,484	15,693
Stock-Based Compensation Expense [Member]
Segment Reporting Information [Line Items]
Operating Expenses	17,107		9,716		34,015	19,724
Depreciation Expense [Member]
Segment Reporting Information [Line Items]
Operating Expenses	$ 741		$ 655		$ 1,367	$ 1,295