Income taxes (Tables)

12 Months Ended

Dec. 31, 2016

Income tax recovery varies from the amounts that would be computed by applying the expected Canadian income tax rate (26%) and U.S. income tax rates (35%). The combined Canadian and U.S. income tax rates of 27.28% (2015 – 27.4%; 2014 – 27.3%) was applied to loss before income taxes as shown in the following table:


	YEARS ENDED DECEMBER 31,
	2016			2015			2014
Computed taxes at combined Canadian and U.S. tax rates	$	(10,095	)	$	(5,997	)	$	(6,561	)
Change in tax rate		—			26			—
Non-deductible expenses		649			446			185
Research and development credits		(1,305	)		—			—
Change in valuation allowance		10,520			5,525			4,519
Other		231			—			—
Reversal of tax benefit related to taxable preferred stock		—			—			1,685
Other impact upon conversion of taxable preferred stock		—			—			172

Income tax recovery	$	—		$	—		$	—

Schedule of Net (Loss) Income Before Taxes

YEARS ENDED DECEMBER 31,
Net loss before taxes:	2016			2015			2014
Canada	$	(31,737	)	$	(18,382	)	$	(20,538	)
U.S.		(5,265	)		(3,478	)		(3,489	)

Total	$	(37,002	)	$	(21,860	)	$	(24,027	)

Components of Deferred Income Tax Assets

Deferred income tax assets and liabilities result from the temporary differences between the amount of assets and liabilities recognized for financial statement and income tax purposes. The significant components of the deferred income tax assets are as follows:


	DECEMBER 31, 2016			DECEMBER 31, 2015
Canadian net operating losses	$	24,049		$	18,282
U.S. net operating losses		3,889			2,499
Research and development deductions and credits		7,331			4,947
Other		1,389			410
Less: valuation allowance		(36,658	)		(26,138	)

Net deferred income tax assets	$	—		$	—