Condensed Statements of Operations and Comprehensive Loss - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Income Statement [Abstract]
Collaboration revenue	$ 2,818	$ 2,482	$ 7,367	$ 6,455
Operating expenses:
Research and development	47,714	37,317	138,151	104,794
General and administrative	13,729	10,094	38,071	27,349
Total operating expenses	61,443	47,411	176,222	132,143
Loss from operations	(58,625)	(44,929)	(168,855)	(125,688)
Other income (expense):
Interest income	6,280	1,342	17,567	2,203
Other expense	(13)	(12)	(489)	(39)
Total other income	6,267	1,330	17,078	2,164
Net loss	(52,358)	(43,599)	(151,777)	(123,524)
Other comprehensive income (loss):
Net unrealized gains (losses) on marketable securities	788	(477)	820	(3,276)
Comprehensive loss	$ (51,570)	$ (44,076)	$ (150,957)	$ (126,800)
Net loss per share, basic (in dollars per share)	$ (0.71)	$ (0.82)	$ (2.11)	$ (2.45)
Net loss per share, diluted (in dollars per share)	$ (0.71)	$ (0.82)	$ (2.11)	$ (2.45)
Weighted-average shares outstanding, basic (in shares)	74,097	53,069	71,987	50,432
Weighted-average shares outstanding, diluted (in shares)	74,097	53,069	71,987	50,432