Condensed Consolidated Statements of Operations and Comprehensive Loss - USD ($) shares in Thousands, $ in Thousands		3 Months Ended
		Mar. 31, 2023	Mar. 31, 2022
Statement of Comprehensive Income [Abstract]
Revenue	[1]	$ 65	$ 553
Operating expenses:
Research and development		44,630	35,830
General and administrative		19,279	34,421
Other operating income, net		(1,288)	(1,122)
Total operating expenses		62,621	69,129
Loss from operations		(62,556)	(68,576)
Interest income, net		4,497	397
Other income, net		1,100	35
Impairment of other investments		(10,000)	0
Total other (loss) income, net		(4,403)	432
Net loss		(66,959)	(68,144)
Comprehensive loss:
Net unrealized gain (loss) on marketable securities		3,720	(4,977)
Comprehensive loss		$ (63,239)	$ (73,121)
Net loss per common share, basic (in dollars per share)		$ (0.27)	$ (0.28)
Net loss per common share, diluted (in dollars per share)		$ (0.27)	$ (0.28)
Weighted-average shares used to compute net loss per common share, basic (in shares)		249,591	244,178
Weighted-average shares used to compute net loss per common share, diluted (in shares)		249,591	244,178

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