CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS (UNAUDITED) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Statement of Comprehensive Income [Abstract]
Collaboration revenue	$ 0	$ 802	$ 1,156	$ 2,406
Operating expenses:
Research and development	17,519	25,854	60,489	71,202
General and administrative	6,842	7,810	23,355	29,991
Restructuring and other charges	6,640	0	6,640	0
Total operating expenses	31,001	33,664	90,484	101,193
Loss from operations	(31,001)	(32,862)	(89,328)	(98,787)
Other income
Gain on sale of business	0	0	0	131,249
Interest income	1,423	1,269	4,403	1,775
Total other income	1,423	1,269	4,403	133,024
Income (loss) before income taxes	(29,578)	(31,593)	(84,925)	34,237
Benefit from (provision for) income taxes	0	46	0	(816)
Loss from equity method investment	(3,376)	(2,179)	(11,917)	(4,131)
Net income (loss)	$ (32,954)	$ (33,726)	$ (96,842)	$ 29,290
Net income (loss) per share-basic	$ (0.57)	$ (0.59)	$ (1.68)	$ 0.51
Net income (loss) per share-diluted	$ (0.57)	$ (0.59)	$ (1.68)	$ 0.51
Weighted-average common shares outstanding-basic	57,853,132	57,447,192	57,788,755	57,372,399
Weighted-average common shares outstanding-diluted	57,853,132	57,447,192	57,788,755	57,901,298