Condensed Consolidated Statements of Operations - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2025	Jun. 30, 2024	Jun. 30, 2025	Jun. 30, 2024
Income Statement [Abstract]
Collaboration and other research and development revenues	$ 3,578	$ 513	$ 8,236	$ 1,649
Revenue type	Service [Member]	Service [Member]	Service [Member]	Service [Member]
Operating expenses:
Research and development	$ 16,181	$ 54,210	$ 42,774	$ 102,997
General and administrative	12,859	18,206	26,234	37,545
Restructuring and impairment charges	26,082	0	66,935	0
Total operating expenses	55,122	72,416	135,943	140,542
Operating loss	(51,544)	(71,903)	(127,707)	(138,893)
Other (expense) income, net:
Other (expense) income, net	(1,758)	(1)	(2,183)	5
Interest related to sale of future revenues	(2,020)	0	(4,236)	0
Interest income, net	2,087	4,297	4,803	9,331
Total other (expense) income, net	(1,691)	4,296	(1,616)	9,336
Net loss	$ (53,235)	$ (67,607)	$ (129,323)	$ (129,557)
Net loss per share, basic (in dollars per share)	$ (0.63)	$ (0.82)	$ (1.54)	$ (1.58)
Net loss per share, diluted (in dollars per share)	$ (0.63)	$ (0.82)	$ (1.54)	$ (1.58)
Weighted-average common shares outstanding, basic (in shares)	84,412,200	82,310,368	83,737,382	82,124,603
Weighted-average common shares outstanding, diluted (in shares)	84,412,200	82,310,368	83,737,382	82,124,603