Statements of Operations and Comprehensive Loss - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Income Statement [Abstract]
Collaboration revenue	$ 9,560	$ 9,224	$ 9,326
Operating expenses:
Research and development	190,968	150,404	101,182
General and administrative	54,190	37,733	26,195
Total operating expenses	245,158	188,137	127,377
Loss from operations	(235,598)	(178,913)	(118,051)
Other income (expense):
Interest income	23,972	4,975	104
Other expense	(594)	(57)	(62)
Total other income (expense)	23,378	4,918	42
Net loss	$ (212,220)	$ (173,995)	$ (118,009)
Net loss per share, basic (in dollars per share)	$ (2.91)	$ (3.34)	$ (2.85)
Net loss per share, diluted (in dollars per share)	$ (2.91)	$ (3.34)	$ (2.85)
Weighted-average shares outstanding, basic (in shares)	73,012	52,162	41,428
Weighted-average shares outstanding, diluted (in shares)	73,012	52,162	41,428
Other comprehensive loss:
Net unrealized gains (losses) on marketable securities	$ 2,823	$ (2,511)	$ (182)
Comprehensive loss	$ (209,397)	$ (176,506)	$ (118,191)