Condensed Consolidated Statements of Operations and Comprehensive Loss (Unaudited) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Income Statement [Abstract]
Collaboration revenue	$ 13,594	$ 14,030	$ 26,200	$ 25,282
Type of Revenue [Extensible List]	us-gaap:LicenseAndServiceMember	us-gaap:LicenseAndServiceMember	us-gaap:LicenseAndServiceMember	us-gaap:LicenseAndServiceMember
Operating expenses:
Research and development	$ 115,276	$ 90,199	$ 212,392	$ 223,294
General and administrative	30,652	22,132	58,100	44,535
Total operating expenses	145,928	112,331	270,492	267,829
Operating loss	(132,334)	(98,301)	(244,292)	(242,547)
Other income (expense), net:
Interest income	12,653	703	24,633	1,243
Loss from equity method investment	(4,000)	(3,252)	(7,048)	(5,997)
Change in fair value of contingent consideration	0	172	(100)	(249)
Total other income (expense), net	8,653	(2,377)	17,485	(5,003)
Net loss	$ (123,681)	$ (100,678)	$ (226,807)	$ (247,550)
Net loss per share, basic	$ (1.4)	$ (1.33)	$ (2.58)	$ (3.29)
Net loss per share, diluted	$ (1.4)	$ (1.33)	$ (2.58)	$ (3.29)
Weighted average shares outstanding, basic	88,185	75,823	87,979	75,282
Weighted average shares outstanding, diluted	88,185	75,823	87,979	75,282
Other comprehensive loss:
Unrealized (loss) gain on marketable securities	$ (1,482)	$ (932)	$ 1,507	$ (6,060)
Other comprehensive gain (loss) from equity method investment	292	(560)	2,086	(862)
Comprehensive loss	$ (124,871)	$ (102,170)	$ (223,214)	$ (254,472)