Consolidated Statements of Operations - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Operating expenses
Research and development	$ 21,453	$ 23,191
General and administrative	10,806	8,758
Change in fair value of contingent consideration	(731)	4,340
Total operating expenses	31,528	36,289
Operating loss	(31,528)	(36,289)
Other income
Change in fair value of warrants liabilities	508	11,637
Interest income	110	13
Total other income	618	11,650
Net loss	$ (30,910)	$ (24,639)
Loss per common share, basic and diluted	$ (0.39)	$ (0.39)
Weighted-average common shares outstanding used to calculate basic and diluted net loss per common share	79,770,334	62,620,227