CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS AND COMPREHENSIVE LOSS (Unaudited) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Income Statement [Abstract]
Collaboration Revenue—from related parties	$ 9,551	$ 20,336	$ 30,687	$ 57,557
Revenue from Contract with Customer, Product and Service [Extensible Enumeration]	us-gaap:RevenueFromRelatedParties	us-gaap:RevenueFromRelatedParties	us-gaap:RevenueFromRelatedParties	us-gaap:RevenueFromRelatedParties
Operating expenses:
Research and development	$ 43,877	$ 38,306	$ 121,115	$ 99,488
General and administrative	10,556	10,667	32,198	24,605
Total operating expenses	54,433	48,973	153,313	124,093
Loss from operations	(44,882)	(28,637)	(122,626)	(66,536)
Other income (expense):
Interest and other Income	1,916	125	2,800	343
Interest and other expense	(36)	(70)	(117)	(124)
Total other income:	1,880	55	2,683	219
Net loss	(43,002)	(28,582)	(119,943)	(66,317)
Other comprehensive loss:
Unrealized (loss) gain on marketable securities	(1,930)	(146)	(5,253)	(18)
Total comprehensive loss	(44,932)	(28,728)	(125,196)	(66,335)
Net loss	$ (43,002)	$ (28,582)	$ (119,943)	$ (66,317)
Net loss per share, basic and diluted	$ (0.79)	$ (0.56)	$ (2.28)	$ (1.42)
Net loss per share, basic and diluted	$ (0.79)	$ (0.56)	$ (2.28)	$ (1.42)
Weighted average common shares outstanding, basic and diluted	54,535,514	50,714,846	52,600,103	46,841,636
Weighted average common shares outstanding, basic and diluted	54,535,514	50,714,846	52,600,103	46,841,636