CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS AND COMPREHENSIVE LOSS (Unaudited) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Revenues:
Grant revenue	$ 2,091	$ 924	$ 5,349	$ 3,843
Collaboration revenue	$ 23,382	$ 1,082	$ 24,910	$ 2,225
Type of Revenue [Extensible List]	us-gaap:LicenseMember	us-gaap:LicenseMember	us-gaap:LicenseMember	us-gaap:LicenseMember
Total revenues	$ 25,473	$ 2,006	$ 30,259	$ 6,068
Operating expenses:
Research and development	16,393	7,360	34,883	32,504
General and administrative	5,708	6,632	19,121	29,988
Impairment of long-term asset	5,306	0	5,306	635
Restructuring	0	(152)	0	11,697
Total operating expenses	27,407	13,840	59,310	74,189
Loss from operations	(1,934)	(11,834)	(29,051)	(68,121)
Other income (expense):
Interest income	950	208	2,894	391
Other income (expense), net	(10)	(23)	(17)	(46)
Interest expense related to the sale of future royalties	0	0	0	(2,605)
Loss on extinguishment of liability related to the sale of future royalties	0	0	0	(3,581)
Change in fair value of derivative liability	0	(26)	0	776
Total other income (expense), net	940	159	2,877	(5,065)
Income (Loss) from Continuing Operations before Interest Expense, Interest Income, Income Taxes, Noncontrolling Interests, Net, Total	(994)	(11,675)	(26,174)	(73,186)
Income tax expense	(2,211)	0	(2,211)	0
Net loss	$ (3,205)	$ (11,675)	$ (28,385)	$ (73,186)
Net loss per share attributable to common stockholders, basic	$ (0.06)	$ (0.33)	$ (0.54)	$ (2.16)
Net loss per share attributable to common stockholders, diluted	$ (0.06)	$ (0.33)	$ (0.54)	$ (2.16)
Weighted average common shares outstanding, basic	52,710,280	35,882,076	52,603,709	33,834,198
Weighted average common shares outstanding, diluted:	52,710,280	35,882,076	52,603,709	33,834,198
Comprehensive loss:
Net loss	$ (3,205)	$ (11,675)	$ (28,385)	$ (73,186)
Other comprehensive gain (loss):
Unrealized gain (loss) on marketable securities	0	0	0	2
Net unrealized gains (losses) on securities	0	0	0	2
Total comprehensive loss	$ (3,205)	$ (11,675)	$ (28,385)	$ (73,184)