Condensed Consolidated Statements of Operations and Comprehensive Loss - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Income Statement [Abstract]
Collaboration revenue		$ 100		$ 100
Operating expenses:
Research and development	$ 21,618	10,432	$ 49,720	32,212
General and administrative	6,985	4,112	19,274	14,916
Total operating expenses	28,603	14,544	68,994	47,128
Loss from operations	(28,603)	(14,444)	(68,994)	(47,028)
Other expense (income), net:
Changes in fair value of warrant liabilities			0	16,240
Other expense (income), net	(3)	22	74	(495)
Total other expense (income), net	(3)	22	74	15,745
Loss before provision for income taxes, net	(28,600)	(14,466)	(69,068)	(62,773)
Provision for income taxes, net	47	39	124	106
Net loss and comprehensive loss	$ (28,647)	$ (14,505)	$ (69,192)	$ (62,879)
Net loss per common share, basic and diluted	$ (2.10)	$ (1.39)	$ (5.50)	$ (6.09)
Weighted-average shares used in computing net loss per common share, basic and diluted	13,672,633	10,441,384	12,571,096	10,331,650