Condensed Statements of Operations and Comprehensive Loss (Unaudited) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Income Statement [Abstract]
Revenue	$ 4,989	$ 1,789	$ 6,238	$ 3,963
Operating expenses:
Research and development	(26,335)	(19,218)	(47,216)	(37,745)
General and administrative	(8,296)	(5,475)	(16,875)	(12,041)
Total operating expenses	(34,631)	(24,693)	(64,091)	(49,786)
Loss from operations	(29,642)	(22,904)	(57,853)	(45,823)
Interest and other income (expense), net	96	73	207	136
Net loss	(29,546)	(22,831)	(57,646)	(45,687)
Net loss attributable to common stockholders	$ (29,546)	$ (22,831)	$ (57,646)	$ (45,687)
Net loss per share, attributable to common stockholders:
Basic (USD per share)	$ (0.82)	$ (0.64)	$ (1.59)	$ (1.28)
Diluted (USD per share)	$ (0.82)	$ (0.64)	$ (1.59)	$ (1.28)
Shares used in computing net loss per share attributable to common stockholders:
Basic (in shares)	36,173,135	35,746,922	36,144,944	35,726,393
Diluted (in shares)	36,173,135	35,746,922	36,144,944	35,726,393
Comprehensive loss:
Net loss	$ (29,546)	$ (22,831)	$ (57,646)	$ (45,687)
Net unrealized gain (loss) on short-term investments	(309)	(12)	(1,058)	2
Total other comprehensive income (loss)	(309)	(12)	(1,058)	2
Comprehensive loss	$ (29,855)	$ (22,843)	$ (58,704)	$ (45,685)