Consolidated Statements of Operations and Comprehensive Loss - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Operating expenses:
Research and development	$ 37,046	$ 11,882
General and administrative	8,605	1,896
Total operating expenses	45,651	13,778
Loss from operations	(45,651)	(13,778)
Other income (expense), net:
Change in fair value of preferred stock tranche obligation		(62,150)
Change in fair value of anti-dilution right liability		(5,765)
Other income, net	1,896
Other expense, net		(21)
Total other income (expense), net	1,896	(67,936)
Net loss	(43,755)	(81,714)
Accretion of redeemable convertible preferred stock to redemption value		(520)
Net loss attributable to common stockholders	$ (43,755)	$ (82,234)
Net loss per share attributable to common stockholders - basic and diluted	$ (2.90)	$ (795.28)
Weighted-average number of shares used in computing net loss per share attributable to common stockholders, basic and diluted	15,070,728	103,403
Net unrealized loss on marketable securities	$ (6)
Comprehensive loss	$ (43,761)	$ (81,714)