Condensed Statements of Operations and Comprehensive Loss (Unaudited) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Operating expenses:
Research and development (including related party expenses of $143 and $1,011 for the three months ended September 30, 2020 and 2019, respectively, and $458 and $1,123 for the nine months ended September 30, 2020 and 2019, respectively)	$ 16,410	$ 9,630	$ 58,903	$ 32,225
General and administrative	4,898	2,510	11,225	6,089
Total operating expenses	21,308	12,140	70,128	38,314
Loss from operations	(21,308)	(12,140)	(70,128)	(38,314)
Other income (expense), net:
Interest expense		(9)	(7)	(33)
Interest income	33	120	212	537
Grant income	787	54	2,152	54
Foreign currency transaction losses	(530)	(186)	(709)	(417)
Change in fair value of the redeemable convertible preferred stock tranche liability		844		2,520
Total other income (expense), net	290	823	1,648	2,661
Net loss and comprehensive loss	$ (21,018)	$ (11,317)	$ (68,480)	$ (35,653)
Net loss per share, basic and diluted	$ (0.41)	$ (2.93)	$ (3.06)	$ (9.54)
Weighted-average shares outstanding, basic and diluted	50,895,358	3,857,298	22,354,212	3,737,779