Condensed Statements of Operations and Comprehensive Loss - USD ($) shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Income Statement [Abstract]
Collaboration revenue	$ 1,795	$ 2,704
Revenue from Contract with Customer, Product and Service [Extensible Enumeration]	us-gaap:LicenseAndServiceMember	us-gaap:LicenseAndServiceMember
Operating expenses:
Research and development	$ 27,688	$ 20,677
General and administrative	8,567	5,884
Total operating expenses	36,255	26,561
Loss from operations	(34,460)	(23,857)
Other income (expense):
Interest income	250	16
Other expense	(25)	(3)
Total other income	225	13
Net loss	(34,235)	(23,844)
Other comprehensive income (loss):
Net unrealized (losses) gains on marketable securities	(1,839)	2
Comprehensive loss	$ (36,074)	$ (23,842)
Net loss per share, basic and diluted	$ (0.71)	$ (0.64)
Weighted-average shares outstanding, basic and diluted	48,246	37,521