CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS AND COMPREHENSIVE LOSS - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Revenue
License and collaboration revenues	$ 71,793	$ 11,424	$ 71,793	$ 11,690
Total revenue	71,793	11,424	71,793	11,690
Expenses
Research and development	116,109	79,853	354,755	216,644
General and administrative	35,183	20,249	93,144	58,074
Total operating expenses	151,292	100,102	447,899	274,718
Loss from operations	(79,499)	(88,678)	(376,106)	(263,028)
Other income (expense), net	2,744	1,342	(2,759)	6,178
Loss before income taxes	(76,755)	(87,336)	(378,865)	(256,850)
Income tax expense	3,299	0	3,299	0
Net loss	(80,054)	(87,336)	(382,164)	(256,850)
Unrealized (loss) gain on available-for-sale investments	(6)	(827)	(164)	568
Comprehensive loss	$ (80,060)	$ (88,163)	$ (382,328)	$ (256,282)
Basic net loss per share (USD per share)	$ (1.55)	$ (1.96)	$ (7.45)	$ (5.87)
Diluted net loss per share (USD per share)	$ (1.55)	$ (1.96)	$ (7.45)	$ (5.87)
Weighted average common shares outstanding, basic (shares)	51,655,259	44,614,226	51,305,547	43,778,607
Weighted average common shares outstanding, diluted (shares)	51,655,259	44,614,226	51,305,547	43,778,607