Consolidated Statements of Operations and Comprehensive Income (Loss) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Collaboration revenue:
Collaboration revenue from customers	[1]	$ 105,065	$ 48,657	$ 335,561
Other collaboration revenue		3,398	4	98
Total collaboration revenue		108,463	48,661	335,659
Operating expenses:
Research and development	[2]	358,732	265,353	212,615
General and administrative		90,475	79,059	60,326
Total operating expenses		449,207	344,412	272,941
Income (loss) from operations		(340,744)	(295,751)	62,718
Interest and other income, net		14,774	4,595	9,241
Income (loss) before income taxes		(325,970)	(291,156)	71,959
Income tax benefit (expense)		(21)	575	(823)
Net income (loss)		(325,991)	(290,581)	71,136
Other comprehensive income (loss):
Net unrealized loss on marketable securities, net of tax		(4,387)	(2,254)	(595)
Comprehensive income (loss)		$ (330,378)	$ (292,835)	$ 70,541
Net income (loss) per share:
Basic net income (loss) per share (usd per share)		$ (2.60)	$ (2.39)	$ 0.65
Diluted net income (loss) per share (usd per share)		$ (2.60)	$ (2.39)	$ 0.63
Weighted-average shares used in calculating:
Basic net income (loss) per share (in shares)		125,530,703	121,524,795	108,974,137
Diluted net income (loss) per share (in shares)		125,530,703	121,524,795	112,703,108

[1] Includes related-party collaboration revenue from customers of $3.2 million, $3.7 million, and $307.4 million for the years ended December 31, 2022, 2021 and 2020 respectively.

[2] Includes expense for cost sharing payments to a related party of $8.2 million for the year ended December 31, 2022 and an offset to expense from related-party cost reimbursements of $6.5 million and $9.3 million for the years ended December 31, 2021 and 2020, respectively.