CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS (Unaudited) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Income Statement [Abstract]
Revenue	$ 24,036	$ 7,363	$ 109,190	$ 15,439
Operating expenses
Research and development	25,940	24,873	88,768	74,935
General and administrative	9,638	8,534	29,074	26,852
Total operating expenses	35,578	33,407	117,842	101,787
Operating loss	(11,542)	(26,044)	(8,652)	(86,348)
Other income (expense):
Change in fair value of equity investment	274		274
Interest expense	(55)		(79)
Interest income	44	28	145	795
Total other income, net	263	28	340	795
Net loss and net loss attributable to common stockholders	$ (11,279)	$ (26,016)	$ (8,312)	$ (85,553)
Net loss per share attributable to common stockholders- basic and diluted	$ (0.19)	$ (0.50)	$ (0.14)	$ (1.65)
Weighted average shares of common stock outstanding- basic and diluted	59,657,677	52,346,715	58,018,550	51,858,032