Condensed Consolidated Statements of Operations and Comprehensive Loss - USD ($) shares in Thousands, $ in Thousands		3 Months Ended		9 Months Ended
		Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Statement of Comprehensive Income [Abstract]
Revenue	[1]	$ 3	$ 2,755	$ 36,297	$ 7,828
Operating expenses:
Research and development		41,607	31,433	121,156	119,408
General and administrative		26,084	21,241	90,959	57,184
Other operating income, net		(1,251)	(758)	(3,544)	(1,526)
Total operating expenses		66,440	51,916	208,571	175,066
Loss from operations		(66,437)	(49,161)	(172,274)	(167,238)
Interest income, net		2,251	270	3,600	842
Other (expense) income, net		(1,068)	16	(1,047)	(117)
Impairment of other investments		(5,000)	0	(5,000)	0
Total other (loss) income, net		(3,817)	286	(2,447)	725
Net loss		(70,254)	(48,875)	(174,721)	(166,513)
Other comprehensive loss:
Net unrealized loss on marketable securities		(1,645)	(138)	(8,373)	(321)
Comprehensive loss		$ (71,899)	$ (49,013)	$ (183,094)	$ (166,834)
Net loss per common share, basic (in dollars per share)		$ (0.28)	$ (0.20)	$ (0.71)	$ (1.66)
Net loss per common share, diluted (in dollars per share)		$ (0.28)	$ (0.20)	$ (0.71)	$ (1.66)
Weighted-average shares used to compute net loss per common share, basic (in shares)		248,320	239,384	246,285	100,603
Weighted-average shares used to compute net loss per common share, diluted (in shares)		248,320	239,384	246,285	100,603

[1] Including related-party revenue of zero and $2,640 for the three months ended September 30, 2022 and 2021, respectively, and $36,299 and $7,697 for the nine months ended September 30, 2022 and 2021, respectively.