Condensed Consolidated Statements of Operations and Comprehensive Loss (Unaudited) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Income Statement [Abstract]
Commercialization revenue	$ 2,020	$ 0	$ 3,697	$ 0
License and collaboration revenue	118	4,459	624	63,352
Total revenue	2,138	4,459	4,321	63,352
Costs and operating expenses:
Cost of commercialization revenue	2,615	0	5,726	0
Research and development expenses	56,888	70,157	175,185	210,018
General and administrative expenses	12,247	18,924	39,454	58,308
Total costs and operating expenses	71,750	89,081	220,365	268,326
Loss from operations	(69,612)	(84,622)	(216,044)	(204,974)
Other income (expense), net:
Interest income	1,218	973	4,715	1,904
Interest expense	(1,395)	(123)	(4,109)	(256)
Gain on sale of ATOM Facility	0	0	0	50,237
Other income (expense), net	(27)	(309)	(234)	(631)
Total other income (expense), net	204	541	372	51,254
Loss before provision for (benefit from) income taxes	(69,816)	(84,081)	(215,672)	(153,720)
Provision for (benefit from) income taxes	(19)	10	4	10
Net loss	(69,797)	(84,091)	(215,676)	(153,730)
Other comprehensive gain (loss):
Unrealized gain (loss) on available-for-sale securities	362	(341)	1,496	(2,591)
Comprehensive loss	$ (69,435)	$ (84,432)	$ (214,180)	$ (156,321)
Basic loss per common share	$ (0.66)	$ (0.82)	$ (2.05)	$ (1.51)
Diluted loss per common share	$ (0.66)	$ (0.82)	$ (2.05)	$ (1.51)
Basic weighted-average shares outstanding	106,401	102,423	105,163	101,590
Diluted weighted-average shares outstanding	106,401	102,423	105,163	101,590