Consolidated Statements of Operations and Comprehensive Income (Loss) - USD ($)	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Revenues:
Total revenues	$ 324,000	$ 33,824,000	$ 1,979,000
Cost of goods sold	0	447,000	0
Gross Profit	324,000	33,377,000	1,979,000
Operating expenses:
Research and development	68,788,000	71,631,000	73,817,000
General and administrative	24,601,000	22,132,000	18,672,000
Acquired in-process research and development	0	0	82,890,000
Total operating expenses	93,389,000	93,763,000	175,379,000
Loss from operations	(93,065,000)	(60,386,000)	(173,400,000)
Other income:
Interest income and other, net	10,970,000	2,919,000	164,000
Gain on sale of business, net	0	229,670,000	0
(Loss) income before income taxes	(82,095,000)	172,203,000	(173,236,000)
Income tax expense	0	36,000	0
Net (loss) income	(82,095,000)	172,167,000	(173,236,000)
Other comprehensive income (loss):
Unrealized gain (loss) on debt investments, net	344,000	(316,000)	(21,000)
Comprehensive (loss) income	$ (81,751,000)	$ 171,851,000	$ (173,257,000)
Per share information:
Net (loss) income, basic (in dollars per share)	$ (0.93)	$ 1.97	$ (2.04)
Net (loss) income, diluted (in dollars per share)	$ (0.93)	$ 1.94	$ (2.04)
Weighted-average shares outstanding, basic (in shares)	88,604,026	87,555,110	84,930,255
Weighted-average shares outstanding, diluted (in shares)	88,604,026	88,776,147	84,930,255
Procurement revenue
Revenues:
Total revenues	$ 0	$ 31,971,000	$ 0
Contract and grant revenue
Revenues:
Total revenues	275,000	942,000	1,928,000
Licensing revenue
Revenues:
Total revenues	49,000	536,000	51,000
Royalty revenue
Revenues:
Total revenues	$ 0	$ 375,000	$ 0