Consolidated Statements of Operations and Comprehensive Loss (Unaudited) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Income Statement [Abstract]
Revenue (note 10):	$ 3,500		$ 3,500
Operating expenses:
Research and development	9,751	$ 6,248	27,093	$ 17,232
General and administrative	2,700	1,938	7,628	6,354
Buy-out of future milestones and royalties (note 12c)		6,000		6,000
Total operating expenses	12,451	14,186	34,721	29,586
Loss from operations	(8,951)	(14,186)	(31,221)	(29,586)
Other income (expense):
Interest income	528	325	1,916	558
Interest expense	(363)	(678)	(1,086)	(1,037)
Foreign exchange gain (loss)	(80)	148	185	(276)
Gain on termination of collaboration agreement (note 9c)				4,398
Loss before income taxes	(8,866)	(14,391)	(30,206)	(25,943)
Income tax (expense) recovery (note 11)	(5)	8	(13)	4
Net loss and comprehensive loss	(8,871)	(14,383)	(30,219)	(25,939)
Net loss attributable to preferred shareholders	(336)	(1,621)	(1,146)	(2,506)
Net loss attributable to common shareholders	$ (8,535)	$ (12,762)	$ (29,073)	$ (23,433)
Net loss per common share (note 4):
Basic and diluted	$ (0.33)	$ (0.63)	$ (1.13)	$ (1.34)
Weighted-average common shares outstanding (note 4):
Basic and diluted	25,793,482	20,306,298	25,773,732	17,472,403