Condensed Consolidated Statements of Operations and Comprehensive Loss - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Revenue:
Contract revenue	$ 1,648	$ 371
Total revenue	1,648	371
Operating expenses:
Research and development	11,667	14,298
General and administrative	4,466	6,012
Total operating expenses	16,133	20,310
Loss from operations	(14,485)	(19,939)
Other income (expense)
Change in fair value of warrant liability	39	(3,519)
Change in fair value of convertible notes	0	(7,469)
Change in fair value of Series C convertible preferred stock	0	(3,592)
Foreign exchange transaction (loss) gain	111	(53)
Earnings from equity method investment	9	55
Interest income (expense), net	86	(2,170)
Total other income (expense)	245	(16,748)
Net loss	(14,240)	(36,687)
Other comprehensive income:
Foreign currency translation adjustment	(96)	46
Comprehensive loss	$ (14,336)	$ (36,641)
Net loss per common share, basic (in dollars per share)	$ (0.48)	$ (1.56)
Net loss per common share, diluted (in dollars per share)	$ (0.48)	$ (1.56)
Weighted average common shares outstanding, basic (in shares)	29,959,251	23,443,851
Weighted average common shares outstanding, diluted (in shares)	29,959,251	23,443,851