Consolidated Statements of Operations and Comprehensive Loss (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Income Statement [Abstract]
Revenue (note 10)	$ 4,358	$ 7,078
Operating expenses:
Research and development	16,308	11,791
General and administrative	4,109	3,320
Total operating expenses	20,417	15,111
Loss from operations	(16,059)	(8,033)
Other income (expense):
Interest income	72	1,116
Interest expense		(330)
Foreign exchange gain (loss)	155	(238)
Loss before income taxes	(15,832)	(7,485)
Income tax recovery (note 11)	68	1
Net loss and comprehensive loss	(15,764)	(7,484)
Net loss attributable to preferred shareholders	(423)	(222)
Net loss attributable to common shareholders	$ (15,341)	$ (7,262)
Net loss per common share (note 4):
Basic and diluted	$ (0.42)	$ (0.22)
Weighted-average common shares outstanding (note 4):
Basic and diluted	36,824,619	33,189,733