Consolidated Statements of Shareholders' Equity (Unaudited) - 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, 2017		$ 35,934			$ 173,841	$ 36,471	$ (173,388)	$ (990)
Balance (in Shares) at Dec. 31, 2017					17,998,420
Net loss		(3,755)					(3,755)
Issued (cancelled) pursuant to exchange agreement (note 9b)				$ 21,825	$ (21,825)
Issued (cancelled) pursuant to exchange agreement (note 9b) (in Shares)				2,868,000	(2,868,000)
Cancelled pursuant to termination of collaboration agreement (note 9c)		(4,470)			$ (4,470)
Cancelled pursuant to termination of collaboration agreement (note 9c) (in Shares)					(1,000,000)
Stock-based compensation expense		670				670
Issued pursuant to exercise of stock options		119			$ 341	(222)
Issued pursuant to exercise of of stock options (in Shares)					40,881
Balance at Mar. 31, 2018		28,498		$ 21,825	$ 147,887	36,919	(177,143)	(990)
Balance (in Shares) at Mar. 31, 2018				2,868,000	14,171,301
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		$ (11,556)
Issued pursuant to exercise of of stock options (in Shares)	[2]	118,719
Balance at Jun. 30, 2018		$ 50,621		$ 21,825	$ 177,012	37,718	(184,944)	(990)
Balance (in Shares) at Jun. 30, 2018				2,868,000	17,640,951
Balance at Mar. 31, 2018		28,498		$ 21,825	$ 147,887	36,919	(177,143)	(990)
Balance (in Shares) at Mar. 31, 2018				2,868,000	14,171,301
Net loss		(7,801)					(7,801)
Issuance of common shares, net of issuance costs (note 9a)		28,957			$ 28,957
Issuance of common shares, net of issuance costs (note 9a) (in shares)					3,440,000
Stock-based compensation expense		657				657
Issued pursuant to exercise of stock options		$ 63			$ 168	(105)
Issued pursuant to exercise of of stock options (in Shares)		34,051	[2]		29,650
Issuance of warrants		$ 247				247
Balance at Jun. 30, 2018		50,621		$ 21,825	$ 177,012	37,718	(184,944)	(990)
Balance (in Shares) at Jun. 30, 2018				2,868,000	17,640,951
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
Cumulative effect of accounting change		(175)					(175)
Net loss		(11,341)					(11,341)
Stock-based compensation expense		476				476
Issued pursuant to exercise of stock options		58			$ 117	(59)
Issued pursuant to exercise of of stock options (in Shares)					21,233
Balance at Mar. 31, 2019		92,313		$ 7,732	$ 266,040	38,932	(219,401)	(990)
Balance (in Shares) at Mar. 31, 2019				1,016,000	25,771,954
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
Net loss		$ (21,348)
Issued pursuant to exercise of of stock options (in Shares)	[2]	25,863
Balance at Jun. 30, 2019		$ 82,787		$ 7,732	$ 266,062	39,391	(229,408)	(990)
Balance (in Shares) at Jun. 30, 2019				1,016,000	25,775,056
Balance at Mar. 31, 2019		92,313		$ 7,732	$ 266,040	38,932	(219,401)	(990)
Balance (in Shares) at Mar. 31, 2019				1,016,000	25,771,954
Net loss		(10,007)					(10,007)
Stock-based compensation expense		470				470
Issued pursuant to exercise of stock options		$ 11			$ 22	(11)
Issued pursuant to exercise of of stock options (in Shares)		3,461	[2]		3,102
Balance at Jun. 30, 2019		$ 82,787		$ 7,732	$ 266,062	$ 39,391	$ (229,408)	$ (990)
Balance (in Shares) at Jun. 30, 2019				1,016,000	25,775,056

[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 six months ended June 30, 2019, 23,472 stock options were exercised for the same number of common shares for cash (six months ended June 30, 2018 – 36,007). In the same period, the Company issued 863 common shares (six months ended June 30, 2018 – 34,524) for the cashless exercise of 2,391 stock options (six months ended June 30, 2018 – 82,712).