Consolidated Statements of Operations and Comprehensive Loss - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Revenues:
Total collaboration and license revenues	$ 77,517	$ 15,000	$ 8,353
Operating expenses:
Research and development (($3,446), $0 and $0 from a related party)	159,348	78,481	49,646
General and administrative	42,404	25,228	13,566
Total operating expenses	201,752	103,709	63,212
Loss from operations	(124,235)	(88,709)	(54,859)
Non-operating income (expense):
Interest and other income, net	1,377	5,201	4,922
Gain on deemed sale from equity method investee	613		1,229
Share of loss from equity method investee	(613)	(1,202)	(886)
Total non-operating income, net	1,377	3,999	5,265
Net loss	(122,858)	(84,710)	(49,594)
Other comprehensive income (loss)	(20)	171	(65)
Comprehensive loss	$ (122,878)	$ (84,539)	$ (49,659)
Net loss per share, basic and diluted	$ (2.24)	$ (1.93)	$ (1.43)
Weighted-average number of shares used to compute basic and diluted net loss per share	54,787,118	43,825,991	34,618,237
License Revenue
Revenues:
Total collaboration and license revenues	$ 55,096	$ 8,000	$ 3,000
Collaboration Revenue
Revenues:
Total collaboration and license revenues	$ 22,421	$ 7,000	$ 5,353