CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS AND COMPREHENSIVE LOSS (Unaudited) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Operating expenses:
Research and development	$ 36,008	$ 25,210	$ 65,103	$ 48,625
General and administrative	8,871	4,236	17,240	9,090
Total operating expenses	44,879	29,446	82,343	57,715
Loss from operations	(44,879)	(29,446)	(82,343)	(57,715)
Other income (expense):
Interest expense	(843)	(892)	(1,681)	(1,806)
Other income (expense), net	17	(90)	5	309
Net loss before income tax	(45,705)	(30,428)	(84,019)	(59,212)
Net loss	(45,705)	(30,428)	(84,019)	(59,212)
Other comprehensive income (expense):
Unrealized gain (loss) on short-term investments	(14)	(110)	(4)	1
Comprehensive loss	$ (45,719)	$ (30,538)	$ (84,023)	$ (59,211)
Net loss per share, basic and diluted	$ (0.74)	$ (2.28)	$ (1.35)	$ (4.44)
Weighted-average number of shares outstanding, basic and diluted	62,150,961	13,370,763	62,066,498	13,346,672