Condensed Statements of Operations and Comprehensive Loss - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Income Statement [Abstract]
Collaboration revenue	$ 2,482	$ 2,163	$ 6,455	$ 7,474
Revenue from Contract with Customer, Product and Service [Extensible Enumeration]	us-gaap:LicenseAndServiceMember	us-gaap:LicenseAndServiceMember	us-gaap:LicenseAndServiceMember	us-gaap:LicenseAndServiceMember
Operating expenses:
Research and development	$ 37,317	$ 24,831	$ 104,794	$ 68,214
General and administrative	10,094	6,612	27,349	18,764
Total operating expenses	47,411	31,443	132,143	86,978
Loss from operations	(44,929)	(29,280)	(125,688)	(79,504)
Other income (expense):
Interest income	1,342	17	2,203	49
Other expense	(12)	(11)	(39)	(16)
Total other income	1,330	6	2,164	33
Net loss	(43,599)	(29,274)	(123,524)	(79,471)
Other comprehensive income (loss):
Net unrealized (losses) gains on marketable securities	(477)	(1)	(3,276)	4
Comprehensive loss	$ (44,076)	$ (29,275)	$ (126,800)	$ (79,467)
Net loss per share, basic	$ (0.82)	$ (0.68)	$ (2.45)	$ (2.01)
Net loss per share, diluted	$ (0.82)	$ (0.68)	$ (2.45)	$ (2.01)
Weighted-average shares outstanding, basic	53,069	43,265	50,432	39,477
Weighted-average shares outstanding, diluted	53,069	43,265	50,432	39,477