Condensed Consolidated Statements of Operations and Comprehensive Loss - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Revenues
Revenues	$ 5,000	$ 0	$ 5,700	$ 0
Operating expenses
Research and development	6,348	8,140	19,531	30,346
General and administrative	1,681	4,163	5,458	12,095
Total operating expenses	8,029	12,303	24,989	42,441
(Gain) loss on dispositions, net	14	0	478	(3,761)
Loss from operations	(3,043)	(12,303)	(19,767)	(38,680)
Other income (expense):
Interest income	6	10	24	392
Interest expense	0	(725)	(4)	(2,473)
Change in fair value of warrant and private placement option liabilities	4,264	12,131	7,506	14,256
Other income	6	0	5	0
Total other income (expense)	4,276	11,416	7,531	12,175
Net income (loss)	1,233	(887)	(12,236)	(26,505)
Less: undistributed earnings to participating securities	(469)	0	0	0
Net income (loss) attributable to common shareholders	$ 764	$ (887)	$ (12,236)	$ (26,505)
Net income (loss) per common share attributable to common shareholders, basic (in dollars per share)	$ 0.08	$ (0.18)	$ (1.21)	$ (5.25)
Net income (loss) per common share attributable to common shareholders, diluted (in dollars per shares)	$ 0.07	$ (0.18)	$ (1.21)	$ (5.25)
Weighted-average shares outstanding, basic (in shares)	10,108,388	5,059,779	10,086,246	5,050,603
Weighted-average shares outstanding, diluted (in shares)	10,194,668	5,059,779	10,086,246	5,050,603
Other comprehensive loss:
Foreign currency translation adjustment	$ (9)	$ 36	$ (9)	$ (26)
Net comprehensive income (loss)	1,224	(851)	(12,245)	(26,531)
Supply agreement
Revenues
Revenues	0	0	700	0
License revenue
Revenues
Revenues	$ 5,000	$ 0	$ 5,000	$ 0