Statements of Operations and Comprehensive Loss - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024
Income Statement [Abstract]
Revenue	$ 0	$ 0
Operating expenses:
Research and development	(109,157)	(169,310)
General and administrative	(47,216)	(59,055)
Total operating expenses	(156,373)	(228,365)
Loss from operations	(156,373)	(228,365)
Interest and other income (expense), net	11,416	21,085
Interest expense	(2,559)	(3,024)
Loss on extinguishment of debt (Note 7)	(1,828)	0
Net loss	$ (149,344)	$ (210,304)
Net loss per share - basic (USD per share)	$ (2.43)	$ (3.47)
Net loss per share - diluted (USD per share)	$ (2.43)	$ (3.47)
Weighted average shares used in computing net loss per share - basic (in shares)	61,366,887	60,538,639
Weighted average shares used in computing net loss per share - diluted (in shares)	61,366,887	60,538,639
Comprehensive loss:
Net loss	$ (149,344)	$ (210,304)
Net unrealized loss on short-term investments	(336)	(24)
Total other comprehensive loss	(336)	(24)
Comprehensive loss	$ (149,680)	$ (210,328)