Consolidated Statements of Operations and Comprehensive Loss (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Income Statement [Abstract]
Revenue (note 11)	$ 7,078
Operating expenses:
Research and development	11,791	$ 9,137
General and administrative	3,320	2,621
Total operating expenses	15,111	11,758
Loss from operations	(8,033)	(11,758)
Other income (expense):
Interest income	1,116	682
Interest expense	(330)	(358)
Foreign exchange gain (loss)	(238)	130
Loss before income taxes	(7,485)	(11,304)
Income tax (expense) recovery (note 12)	1	(37)
Net loss and comprehensive loss	(7,484)	(11,341)
Net loss attributable to preferred shareholders	(222)	(430)
Net loss attributable to common shareholders	$ (7,262)	$ (10,911)
Net loss per common share (note 5):
Basic and diluted	$ (0.22)	$ (0.42)
Weighted-average common shares outstanding (note 5):
Basic and diluted	33,189,733	25,753,836