Consolidated Statement of Shareholders' Equity - USD ($) $ in Thousands		Total		Convertible Preferred Shares [Member]	Common Shares [Member]	Additional Paid-in Capital [Member]	Accumulated Deficit [Member]	Accumulated Other Comprehensive Loss [Member]	[1]
Balance at Dec. 31, 2016		$ 63,901			$ 173,246	$ 34,326	$ (142,681)	$ (990)
Balance (in Shares) at Dec. 31, 2016					17,930,590
Net loss		(30,704)					(30,704)
Stock-based compensation expense		2,460				2,460
Issued pursuant to exercise of stock options		$ 177			$ 595	(415)	(3)
Issued pursuant to exercise of stock options (in Shares)		71,006	[2]		67,830
Issuance of warrants		$ 100				100
Balance at Dec. 31, 2017		35,934			$ 173,841	36,471	(173,388)	(990)
Balance (in Shares) at Dec. 31, 2017					17,998,420
Net loss		(34,497)					(34,497)
Issuance of common shares,net of issuance costs (note 10a)		102,850			$ 102,850
Issuance of common shares, net of issuance costs (note 10a) (in shares)					9,540,000
Issued (cancelled) pursuant to exchange agreement (note 10d)				$ 21,825	$ (21,825)
Issued (cancelled) pursuant to exchange agreement (note 10d) (in Shares)				2,868,000	(2,868,000)
Conversion of preferred shares to common shares (note 10d)				$ (14,093)	$ 14,093
Conversion of preferred shares to common shares (note 10d) (in shares)				(1,852,000)	1,852,000
Cancelled pursuant to termination of collaboration agreement (note 12a)		(4,470)			$ (4,470)
Cancelled pursuant to termination of collaboration agreement (note 12a) (in Shares)					(1,000,000)
Stock-based compensation expense		$ 2,652				2,652
Issued pursuant to exercise of stock options (in Shares)	[2]	251,163
Issued pursuant to exercise of stock options and warrants		$ 288			$ 1,434	(1,146)
Issued pursuant to exercise of stock options and warrants (in shares)					228,301
Issuance of warrants		538				538
Balance at Dec. 31, 2018		$ 103,295		$ 7,732	$ 265,923	$ 38,515	$ (207,885)	$ (990)
Balance (in Shares) at Dec. 31, 2018				1,016,000	25,750,721

[1] Our accumulated other comprehensive loss is entirely related to historical cumulative translation adjustments from the application of U.S. dollar reporting when the functional currency of the Company was the Canadian dollar.

[2] During the year ended December 31, 2018, 49,502 (2017 – 63,425) stock options were exercised for the same number of common shares in exchange for cash. In the same period, the Company issued 106,474 (2017 – 4,405) common shares for the cashless exercise of 201,661 (2017 – 7,581) stock options.