Condensed Consolidated Statements of Operations and Comprehensive Loss (unaudited) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Operating expenses
Research and development	$ 3,696	$ 5,587	$ 7,684	$ 12,751
General and administrative	2,467	2,464	5,110	5,443
Change in fair value of contingent consideration	616	3,034	(242)	2,047
Total operating expenses	6,779	11,085	12,552	20,241
Operating loss	(6,779)	(11,085)	(12,552)	(20,241)
Other income
Change in fair value of warrants liabilities	2	56	29	257
Interest income	52	41	74	42
Total other income	54	97	103	299
Net loss	(6,725)	(10,988)	(12,449)	(19,942)
Other comprehensive loss
Foreign currency translation adjustment	1		(1)
Total comprehensive loss	$ (6,724)	$ (10,988)	$ (12,450)	$ (19,942)
Net loss per common share basic	$ (0.06)	$ (0.14)	$ (0.12)	$ (0.25)
Net loss per common share diluted	$ (0.06)	$ (0.14)	$ (0.12)	$ (0.25)
Weighted-average common shares outstanding used to calculate basic net loss per common share	120,088,816	79,747,506	100,165,432	79,721,290
Weighted-average common shares outstanding used to calculate diluted net loss per common share	120,088,816	79,747,506	100,165,432	79,721,290