CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS AND COMPREHENSIVE LOSS (Unaudited) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Income Statement [Abstract]
Collaboration Revenue—from related parties	$ 11,514	$ 18,519	$ 21,136	$ 37,221
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	$ 41,293	$ 35,220	$ 77,238	$ 61,181
General and administrative	11,031	8,029	21,642	13,939
Total operating expenses	52,324	43,249	98,880	75,120
Loss from operations	(40,810)	(24,730)	(77,744)	(37,899)
Other income (expense):
Interest and other Income	594	98	884	217
Interest and other expense	(41)	(28)	(81)	(53)
Total other income:	553	70	803	164
Net loss	(40,257)	(24,660)	(76,941)	(37,735)
Other comprehensive loss:
Unrealized (loss) gain on marketable securities	(767)	14	(3,323)	128
Total comprehensive loss	(41,024)	(24,646)	(80,264)	(37,607)
Net loss	$ (40,257)	$ (24,660)	$ (76,941)	$ (37,735)
Net loss per share, basic and diluted	$ (0.78)	$ (0.55)	$ (1.49)	$ (0.84)
Net loss per share, basic and diluted	$ (0.78)	$ (0.55)	$ (1.49)	$ (0.84)
Weighted average common shares outstanding, basic and diluted	51,772,440	45,094,238	51,712,081	44,873,083
Weighted average common shares outstanding, basic and diluted	51,772,440	45,094,238	51,712,081	44,873,083