Condensed Consolidated Statements of Operations and Comprehensive Loss - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Operating expenses
Research and development	$ 4,486	$ 6,460
General and administrative	1,453	2,012
Total operating expenses	5,939	8,472
Other operating expense
Loss on dispositions, net	0	464
Loss from operations	(5,939)	(8,936)
Other income (expense):
Interest income	14	10
Interest expense	0	(4)
Change in fair value of warrant derivative and private placement option liabilities	(1,637)	(2,337)
Total other expense	(1,623)	(2,331)
Net loss	$ (7,562)	$ (11,267)
Net loss per common share attributable to common shareholders, basic (in dollars per share)	$ (0.25)	$ (1.12)
Net loss per common share attributable to common shareholders, diluted (in dollars per share)	$ (0.25)	$ (1.12)
Weighted-average shares outstanding, basic (in shares)	30,819,578	10,034,970
Weighted-average shares outstanding, diluted (in shares)	30,819,578	10,034,970
Net loss	$ (7,562)	$ (11,267)
Other comprehensive loss:
Foreign currency translation adjustment	(3)	0
Comprehensive loss	$ (7,565)	$ (11,267)