Document And Entity Information - USD ($) $ in Millions	12 Months Ended
Document And Entity Information - USD ($) $ in Millions	Dec. 31, 2017	Mar. 02, 2018	Jun. 30, 2017
Document And Entity Information [Abstract]
Entity Registrant Name	Xenon Pharmaceuticals Inc.
Document Type	10-K
Current Fiscal Year End Date	--12-31
Entity Common Stock, Shares Outstanding		18,002,499
Entity Public Float			$ 43.4
Amendment Flag	false
Trading Symbol	XENE
Entity Central Index Key	0001582313
Entity Current Reporting Status	Yes
Entity Voluntary Filers	No
Entity Filer Category	Smaller Reporting Company
Entity Well-known Seasoned Issuer	No
Document Period End Date	Dec. 31, 2017
Document Fiscal Year Focus	2017
Document Fiscal Period Focus	FY

Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Current assets:
Cash and cash equivalents	$ 20,486	$ 17,095
Marketable securities	23,181	47,051
Accounts receivable	438	200
Prepaid expenses and other current assets	716	1,329
Total current assets	44,821	65,675
Prepaid expenses, long-term	230	408
Property, plant and equipment, net (note 6)	1,070	1,404
Total assets	46,121	67,487
Current liabilities:
Accounts payable and accrued expenses (note 7)	3,383	3,586
Loan payable, current portion (note 8)	700
Total current liabilities	4,083	3,586
Loan payable, long-term (note 8)	6,104
Total liabilities	10,187	3,586
Shareholders’ equity:
Common shares, without par value; unlimited shares authorized; issued and outstanding: 17,998,420 (December 31, 2016 - 17,930,590) (note 9b)	173,841	173,246
Additional paid-in capital	36,471	34,326
Accumulated deficit	(173,388)	(142,681)
Accumulated other comprehensive loss	(990)	(990)
Shareholders' equity	35,934	63,901
Total liabilities and shareholders’ equity	46,121	67,487
Commitments and contingencies (note 12)

Consolidated Balance Sheets (Parenthetical) - $ / shares	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Statement Of Financial Position [Abstract]
Common shares, without par value
Common shares, shares authorized	Unlimited	Unlimited
Common shares, Issued	17,998,420	17,930,590
Common shares, Outstanding	17,998,420	17,930,590

Consolidated Statements of Operations and Comprehensive Loss - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Revenue:
Collaboration revenue (note 11)	$ 309	$ 1,767	$ 15,573
Royalties	2	36	4
Revenues	311	1,803	15,577
Operating expenses:
Research and development	25,573	19,828	15,152
General and administrative	7,313	6,792	9,786
Total operating expenses	32,886	26,620	24,938
Loss from operations	(32,575)	(24,817)	(9,361)
Other income (expense):
Interest income	477	504	542
Foreign exchange gain (loss)	1,394	1,316	(6,933)
Net loss and comprehensive loss	$ (30,704)	$ (22,997)	$ (15,752)
Net loss per common share (note 5):
Basic	$ (1.71)	$ (1.48)	$ (1.10)
Diluted	$ (1.72)	$ (1.48)	$ (1.10)
Weighted-average common shares outstanding (note 5):
Basic	17,985,061	15,493,474	14,281,837
Diluted	18,001,759	15,493,474	14,281,837

Consolidated Statement of Shareholders' Equity - USD ($)
$ in Thousands

Total

Common Shares [Member]

Additional Paid-in Capital [Member]

Accumulated Deficit [Member]

Accumulated Other Comprehensive Income (Loss) [Member]

^[1]

Balance at Dec. 31, 2014

$ 72,779

$ 147,157

$ 30,346

$ (103,734)

$ (990)

Balance (in Shares) at Dec. 31, 2014

14,181,333

Net loss

(15,752)

Stock-based compensation expense

2,077

Issued pursuant to exercise of stock options

$ 278

$ 1,477

(992)

(207)

Issued pursuant to exercise of stock options (in Shares)

270,254

204,003

Fair value adjustment upon reclassification of stock options (note 3l)

$ 1,652

1,652

Balance at Dec. 31, 2015

61,034

$ 148,634

33,083

(119,693)

(990)

Balance (in Shares) at Dec. 31, 2015

14,385,336

Net loss

(22,997)

Issuance of common shares, net of issuance costs

23,832

$ 23,832

Issuance of common shares, net of issuance costs (in Shares)

3,450,000

Stock-based compensation expense

2,186

Issued pursuant to exercise of stock options

$ 132

$ 780

(657)

Issued pursuant to exercise of stock options (in Shares)

121,292

95,254

Fair value adjustment upon reclassification of stock options (note 3l)

$ (286)

(286)

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)

Stock-based compensation expense

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

[1]	December 31, 2017, 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 as described in note 3m.
[2]	During the year ended December 31, 2017, 63,425 (2016 – 47,413) stock options were exercised for the same number of common shares in exchange for cash. In the same period, the Company issued 4,405 (2016 – 47,841) common shares for the cashless exercise of 7,581 (2016 – 73,879) stock options.

Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Operating activities:
Net loss	$ (30,704)	$ (22,997)	$ (15,752)
Items not involving cash:
Depreciation	649	864	1,038
Amortization of discount on term loan	11
Stock-based compensation	2,236	2,161	3,729
Unrealized foreign exchange (gain) loss	(1,474)	(1,300)	6,902
Changes in operating assets and liabilities:
Accounts receivable	(232)	121	(107)
Prepaid expenses, and other current assets	613	571	(1,214)
Prepaid expenses, long term	178	686	(1,094)
Accounts payable and accrued expenses	(3)	484	17
Deferred revenue		(157)	(11,622)
Net cash used in operating activities	(28,726)	(19,567)	(18,103)
Investing activities:
Purchases of property, plant and equipment	(315)	(279)	(551)
Purchase of marketable securities	(28,007)	(47,563)
Proceeds from marketable securities	52,616		10,745
Net cash provided by (used in) investing activities	24,294	(47,842)	10,194
Financing activities:
Proceeds from issuance of term loan, net of issuance costs (note 8)	6,893
Issuance of common shares pursuant to exercise of stock options	177	132	278
Issuance of common shares, net of issuance costs (note 9a)		23,832
Net cash provided by financing activities	7,070	23,964	278
Effect of exchange rate changes on cash and cash equivalents	753	1,889	(5,744)
Increase (decrease) in cash and cash equivalents	3,391	(41,556)	(13,375)
Cash and cash equivalents, beginning of year	17,095	58,651	72,026
Cash and cash equivalents, end of year	20,486	17,095	58,651
Supplemental disclosures:
Interest received	740	341	659
Supplemental disclosures of non-cash transactions:
Fair value of options exercised on a cashless basis	$ 25	$ 404	$ 744

Nature of the Business

12 Months Ended

Dec. 31, 2017

Organization Consolidation And Presentation Of Financial Statements [Abstract]

Nature of the business

1.	Nature of the business:

Xenon Pharmaceuticals Inc. (the “Company”), incorporated in 1996 under the British Columbia Business Corporations Act and continued federally in 2000 under the Canada Business Corporation Act, is a clinical stage biopharmaceutical company focused on developing innovative therapeutics to improve the lives of patients with neurological disorders. Building upon its extensive knowledge of human genetics and diseases caused by mutations in ion channels, known as channelopathies, the Company is advancing a novel product pipeline of central nervous system therapies to address areas of high unmet medical need, such as epilepsy and pain.

The Company has incurred significant operating losses since inception. As of December 31, 2017, the Company had an accumulated deficit of $173,388 and a $30,704 net loss for the year ended December 31, 2017. Management expects to continue to incur significant expenses in excess of revenue and to incur operating losses for the foreseeable future. To date, the Company has financed its operations primarily through funding received from collaboration and license agreements, private placements of common and preferred shares, public offerings of common shares, debt financing, and government funding.

Until such time as the Company can generate substantial product revenue, if ever, management expects to finance the Company’s cash needs through a combination of collaboration agreements and equity or debt financings. The continuation of the research and development activities and the future commercialization of its products are dependent on the Company’s ability to successfully raise additional funds when needed. It is not possible to predict either the outcome of future research and development programs or the Company’s ability to continue to fund these programs in the future.

Basis of Presentation

12 Months Ended

Dec. 31, 2017

Accounting Policies [Abstract]

Basis of presentation

2.	Basis of presentation:

These consolidated financial statements are presented in U.S. dollars.

The accompanying audited consolidated financial statements of the Company have been prepared in accordance with United States generally accepted accounting principles (“U.S. GAAP”).

The Company has one wholly-owned subsidiary as at December 31, 2017, Xenon Pharmaceuticals USA Inc., which was incorporated in Delaware on December 2, 2016.

These consolidated financial statements include the accounts of the Company and its wholly-owned subsidiary. All intercompany transactions and balances have been eliminated on consolidation.

Significant Accounting Policies

12 Months Ended

Dec. 31, 2017

Accounting Policies [Abstract]

Significant accounting policies

3.	Significant accounting policies:

(a)

Use of estimates:

The preparation of the consolidated financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenue and expenses during the reporting period. Significant areas of estimates include, but are not limited to, the timing of revenue recognition, the determination of stock-based compensation and the amounts recorded as accrued liabilities. Actual results could differ materially from those estimates. Estimates and assumptions are reviewed quarterly. All revisions to accounting estimates are recognized in the period in which the estimates are revised and in any future periods affected.

(b)

Cash and cash equivalents:

Cash equivalents are highly liquid investments that are readily convertible into cash with terms to maturity of three months or less when acquired. Cash equivalents are recorded at cost plus accrued interest. The carrying value of these cash equivalents approximates their fair value.

(c)

Marketable securities:

Marketable securities are investments with original maturities exceeding three months, and have remaining maturities of less than one year. Marketable securities accrue interest based on a fixed interest rate for the term. The carrying value of marketable securities is recorded at cost plus accrued interest, which approximates their fair value.

(d)

Intellectual Property

The costs incurred in establishing and maintaining patents for intellectual property developed internally are expensed in the period incurred.

(e)

Property, plant and equipment:

Property, plant and equipment are stated at cost less accumulated depreciation and/or accumulated impairment losses, if any. Repairs and maintenance costs are expensed in the period incurred.

Property, plant and equipment are amortized over their estimated useful lives using the straight-line method based on the following rates:

Asset		Rate
Research equipment		5 years
Office furniture and equipment		5 years
Computer equipment		3 years
Leasehold improvements		Over the lesser of lease term or estimated useful life

(f)

Impairment of long-lived assets:

The Company monitors its long-lived assets for indicators of impairment. If such indicators are present, the Company assesses the recoverability of affected assets by determining whether the carrying value of such assets is less than the sum of the undiscounted future cash flows of the assets. If such assets are found not to be recoverable, the Company measures the amount of such impairment by comparing the carrying value of the assets to the fair value of the assets, with the fair value generally determined based on the present value of the expected future cash flows associated with the assets. No impairment of long-lived assets was noted during the years ended December 31, 2017 and 2016.

(g)

Concentration of credit risk and of significant customers:

Financial instruments that potentially subject the Company to significant concentrations of credit risk consist primarily of cash and cash equivalents. Cash and cash equivalents were held at major financial institutions in Canada and the United States. Such deposits may be in excess of insured limits in the event of non-performance by the institutions; however, the Company does not anticipate non-performance.

Collaborators whose collaboration research and development revenue accounted for 10% or more of total revenues were as follows:

	Year ended December 31,
	2017		2016		2015
Genentech	$	250	$	1,651	$	4,563
Teva		59		116		11,010

(h)

Financial instruments and fair value:

We measure certain financial instruments and other items at fair value.

To determine the fair value, we use the fair value hierarchy for inputs used to measure fair value of financial assets and liabilities. This hierarchy prioritizes the inputs to valuation techniques used to measure fair value into three levels: Level 1 (highest priority), Level 2, and Level 3 (lowest priority).

•

Level 1 - Unadjusted quoted prices in active markets for identical instruments.

•

Level 2 - Inputs other than quoted prices included within Level 1 that are observable for the asset or liability, either directly or indirectly. Level 2 inputs include quoted prices for similar assets or liabilities in active markets, quoted prices for identical or similar assets or liabilities in markets that are not active, inputs other than quoted prices that are observable for the asset or liability (i.e., interest rates, yield curves, etc.), and inputs that are derived principally from or corroborated by observable market data by correlation or other means (market corroborated inputs).

•

Level 3 - Inputs are unobservable and reflect the Company’s assumptions as to what market participants would use in pricing the asset or liability. The Company develops these inputs based on the best information available.

Assets and liabilities are classified based on the lowest level of input that is significant to the fair value measurements. Changes in the observability of valuation inputs may result in a reclassification of levels for certain securities within the fair value hierarchy.

The Company’s Level 1 assets include cash and cash equivalents and marketable securities with quoted prices in active markets. The carrying amount of accounts receivables, accounts payable and accrued expenses approximates fair value due to the nature and short-term of those instruments. As quoted prices for the liability classified stock options, included in the consolidated balance sheet as accounts payable and accrued expenses, are not readily available, the Company has used a Black-Scholes pricing model to estimate fair value using Level 3 inputs as defined above. The Company’s term loan, which was finalized in December 2017, bears interest at a rate that approximates prevailing market rates for instruments with similar characteristics and, accordingly, the carrying value of the loan approximates fair value.

(i)

Revenue recognition:

The Company recognizes revenue when all of the following criteria are met: (i) persuasive evidence of an arrangement exists; (ii) delivery has occurred or services have been rendered; (iii) the Company’s price to the collaborator is fixed or determinable; and (iv) collectability is reasonably assured.

The Company generates revenue primarily through collaboration agreements.

Under these collaboration agreements, the Company is eligible to receive non-refundable upfront payments, funding for research and development services, milestone payments, other contingent payments and royalties. In assessing the appropriate revenue recognition related to a collaboration agreement, the Company first determines whether an arrangement includes multiple elements, such as the delivery of intellectual property rights and research and development services. Revenues associated with multiple element arrangements are attributed to the various elements based on their relative fair values or are recognized as a single unit of accounting when relative fair values are not determinable.

Non-refundable upfront payments are recorded as deferred revenue on the balance sheet and are recognized as collaboration revenue over the estimated period of research performance that is consistent with the terms of the research and development obligations contained in the collaboration agreement. The Company periodically reviews the estimated period of performance based on the progress made under each arrangement.

The Company recognizes funding related to full-time equivalent staffing funded through collaboration agreements as revenue on a gross basis as it performs or delivers such related services in accordance with the agreement terms, provided that it will receive payment for such services upon standard payment terms.

The Company recognizes revenue contingent upon its achievement of a milestone, in its entirety in the period the milestone is achieved, only if the milestone meets certain criteria and is considered to be substantive. Payments received upon the occurrence of milestones that are non-substantive are deferred and recognized as revenue over the estimated period of performance applicable to the associated collaborative agreement.

(j)

Research and development costs:

Research and development costs are expensed in the period incurred.

Certain development activity costs, such as pre-clinical costs, manufacturing costs and clinical trial costs, are a component of research and development costs and include fees paid to contract research organizations, investigators and other vendors who conduct certain product development activities on behalf of the Company. The amount of expenses recognized in a period related to service agreements is based on estimates of the work performed using the accrual basis of accounting. These estimates are based on patient enrollment, services provided and goods delivered, contractual terms and experience with similar contracts. The Company monitors these factors and adjusts the estimates accordingly. Payments made to third parties under these arrangements in advance of the receipt of the related services are recorded as prepaid expenses until the services are rendered.

(k)

Stock-based compensation:

The Company grants stock options to employees, directors and officers pursuant to a stock option plan described in note 9c.

Employee stock-based compensation expense is measured at the grant date, based on the estimated fair value of the award, and is recognized as an expense, net of actual forfeitures, over the requisite service period with a corresponding increase in additional paid-in capital. Stock-based compensation expense is amortized on a straight-line basis over the requisite service period for the entire award, which is generally the vesting period of the award. Any consideration received on exercise of stock options is credited to share capital.

(l)

Liability classified stock options:

Stock option awards accounted for under Accounting Standards Codification (“ASC”) 718 - Compensation - Stock Options (“ASC 718”) that provide for an exercise price that is not denominated in: (a) the currency of the market in which a substantial portion of the Company’s equity securities trade, (b) the currency in which the optionee’s pay is denominated, or (c) the Company’s functional currency, are classified as liabilities. Following the change in functional currency on January 1, 2015, described in (m) below, options granted to members of the Company’s board of directors and certain consultants with exercise prices denominated in Canadian dollars were subject to liability accounting, resulting in a reclassification of these awards from additional paid-in capital to liability classified stock options.

In September 2015, the Company modified certain compensation arrangements to be denominated in Canadian dollars. Following this modification, options denominated in Canadian dollars that were granted to members of the Company’s board of directors and certain consultants met the criteria for equity classification with fair value at the modification date calculated using the Black-Scholes option-pricing model and reclassified from liability classified stock options back to additional paid-in capital. The modified awards are accounted for as equity awards from the date of modification.

Stock options awards accounted for under ASC 815 - Derivatives and Hedging (“ASC 815”), that provide for an exercise price which is not denominated in the Company’s functional currency are required to be classified as liabilities. Certain stock option awards with exercise prices denominated in Canadian dollars are accounted for under ASC 815 and classified as liabilities. As of December 31, 2017, such liability classified stock options totaled $37 (2016 – $261) and are included in the consolidated balance sheet as accounts payable and accrued expenses.

Liability classified stock options are re-measured at fair value using the Black-Scholes option-pricing model at each balance sheet date until exercised or cancelled, with changes in fair value recognized as additional paid-in capital for ASC 718 awards or general and administrative stock-based compensation expense for ASC 815 awards for the period. The Black-Scholes option pricing model uses various inputs to measure fair value, including fair value of the Company’s underlying common shares at the grant date, expected term, expected volatility, risk-free interest rate and expected dividend yield of the Company’s common shares.

(m)

Foreign currency translation:

The Company’s functional and reporting currency is the U.S. dollar. The functional currency of the Company changed to U.S. dollars from Canadian dollars on January 1, 2015 based on management’s analysis of the changes in the primary economic environment in which the Company operates. The Company’s reporting currency did not change. The change in functional currency is accounted for prospectively from January 1, 2015.

For periods commencing January 1, 2015, monetary assets and liabilities denominated in foreign currencies are translated into U.S. dollars using exchange rates in effect at the balance sheet date. Opening balances related to non-monetary assets and liabilities are based on prior period translated amounts, and nonmonetary assets and nonmonetary liabilities incurred after January 1, 2015 are translated at the approximate exchange rate prevailing at the date of the transaction. Revenue and expense transactions are translated at the approximate exchange rate in effect at the time of the transaction. Foreign exchange gains and losses are included in the consolidated statement of operations and comprehensive income (loss) as foreign exchange gain (loss).

(n)

Income taxes:

Deferred income taxes are recognized for the future tax consequences attributable to differences between the carrying amounts of assets and liabilities and their respective tax bases and net operating loss and credit carryforwards. Deferred income tax assets and liabilities are measured at enacted rates expected to apply to taxable income in the years in which those temporary differences and carryforwards are expected to be recovered or settled. The effect on deferred income tax assets and liabilities of a change in tax rates is recognized in the consolidated statement of operations and comprehensive income (loss) in the period that includes the enactment date. A valuation allowance is provided when realization of deferred income tax assets does not meet the more-likely-than-not criterion for recognition.

(o)

Deferred tenant inducements:

Deferred tenant inducements, which include leasehold improvements paid for by the landlord and free rent, are included in the consolidated balance sheet as accounts payable and accrued expenses and recognized as a reduction of rent expense on a straight-line basis over the term of the lease.

(p)

Segment and geographic information:

Operating segments are defined as components of an enterprise about which separate discrete information is available for evaluation by the chief operating decision maker, or decision making group, in deciding how to allocate resources and in assessing performance. The Company views its operations and manages its business in one operating segment.

(q)

Comparative figures:

Certain comparative figures have been reclassified to conform to the consolidated financial statement presentation adopted for the current year.

Future Changes in Accounting Policies

12 Months Ended

Dec. 31, 2017

Accounting Changes And Error Corrections [Abstract]

Future changes in accounting policies

4.	Future changes in accounting policies:

In May 2014, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) 2014-09, Revenue from Contracts with Customers (ASC 606) to clarify the principles of recognizing revenue and to develop a common revenue standard that would remove inconsistencies in revenue requirements, leading to improved comparability of revenue recognition practices across entities and industries. The standard, as subsequently amended, stipulates that an entity should recognize revenue to depict the transfer of promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services. The new guidance will be effective for public entities for fiscal years and interim periods within those years, beginning after December 15, 2017. The Company plans to adopt the standard under the modified retrospective approach on January 1, 2018 and has identified one ongoing significant collaboration agreement with respect to revenue, the collaborative research and license agreement with Genentech, a member of the Roche Group, described in note 11b. The Company has evaluated the new guidance and does not expect a material impact on the Company’s financial statements as a result of the application of the guidance on revenue previously recognized under this agreement. In addition, application of the new guidance is also not expected to result in a material change in the amount or timing of revenues recognized, as compared to prior practice, as it relates to the milestone and royalty payments the Company is eligible to receive in future periods under this agreement.

In February 2016, the FASB issued ASU 2016-02, Leases (Topic 842): Recognition and Measurement of Financial Assets and Financial Liabilities. The update requires the recognition of lease assets and lease liabilities by lessees for those leases classified as operating leases under previous U.S. GAAP. The new guidance retains a distinction between finance leases and operating leases, with cash payments from operating leases classified within operating activities in the statement of cash flows. These amendments will be effective for public entities for fiscal years and interim periods within those years, beginning after December 15, 2018. The Company is currently evaluating the new guidance to determine the impact it will have on the Company’s consolidated financial statements.

Net Income (Loss) Per Common Share

12 Months Ended

Dec. 31, 2017

Earnings Per Share [Abstract]

Net income (loss) per common share

5.	Net income (loss) per common share:

Basic net income (loss) per common share is computed by dividing the net income (loss) by the weighted average number of common shares outstanding for the period. Diluted net income (loss) per common share is computed by adjusting the numerator and denominator of the basic net income (loss) per share calculation for the potential impact of dilutive securities.

For the year ended December 31, 2017, 2,172,034 stock options and warrants were excluded from the calculation of diluted net income per common share as their inclusion would be anti-dilutive. For the years ended December 31, 2016 and December 31, 2015, all stock options were anti-dilutive and were excluded from the diluted weighted average common shares outstanding for those periods.

The following is a reconciliation of the numerators and denominators of basic and diluted net loss per common share:

	Year Ended December 31,
	2017			2016			2015
Numerator:
Net loss used to compute net loss per common share:
Basic	$	(30,704	)	$	(22,997	)	$	(15,752	)
Adjustment for change in fair value of liability classified stock options		(187	)		—			—
Diluted	$	(30,891	)	$	(22,997	)	$	(15,752	)
Denominator:
Weighted average number of common shares:
Basic		17,985,061			15,493,474			14,281,837
Adjustment for dilutive effect of stock options		16,698			—			—
Diluted		18,001,759			15,493,474			14,281,837
Net loss per common share - basic	$	(1.71	)	$	(1.48	)	$	(1.10	)
Net loss per common share - diluted	$	(1.72	)	$	(1.48	)	$	(1.10	)

Property, Plant and Equipment

12 Months Ended

Dec. 31, 2017

Property Plant And Equipment [Abstract]

Property, Plant and Equipment

6.	Property, plant and equipment:

Property, plant and equipment consisted of the following:

	December 31,
	2017			2016
Research equipment	$	6,984		$	6,789
Office furniture and equipment		1,043			1,045
Computer equipment		2,311			2,283
Leasehold improvements		6,370			6,370
Less: accumulated depreciation and amortization		(15,638	)		(15,083	)
Net book value	$	1,070		$	1,404

Accounts Payable and Accrued Expenses

12 Months Ended

Dec. 31, 2017

Payables And Accruals [Abstract]

Accounts Payable and Accrued Expenses

7.	Accounts payable and accrued expenses:

Accounts payable and accrued expenses consisted of the following:

	December 31,
	2017		2016
Trade payables	$	1,253	$	1,463
Employee compensation, benefits, and related accruals		1,017		872
Consulting and contracted research		817		1,029
Professional fees		252		93
Other		44		129
Total	$	3,383	$	3,586

Term Loan

12 Months Ended

Dec. 31, 2017

Debt Disclosure [Abstract]

Term Loan

8.	Term Loan:

On December 18, 2017, the Company entered into a Loan and Security Agreement (the “Loan Agreement”) with Silicon Valley Bank (the “Bank”), pursuant to which the Bank agreed to extend term loans to the Company with an aggregate principal amount of up to $15,000, in three tranches (the “Term Loans”). The Company borrowed an initial tranche of $7,000, with the remaining $8,000 available to be drawn in two separate tranches, at the Company’s option, subject to the achievement of certain clinical and financial milestones.

The Loan Agreement accrues interest at a floating per annum rate of 0.5% above the prime rate, and is payable monthly commencing in January 2018. The initial tranche is interest only until September 30, 2018, followed by 30 months of equal principal and interest payments, maturing on March 31, 2021. If the second tranche is advanced, then both the first and second tranches will be interest only until March 31, 2019, followed by 24 months of equal principal and interest payments, maturing on March 31, 2021. The third tranche, if advanced, will be interest only until September 30, 2019, followed by 24 months of equal principal and interest payments, maturing on September 30, 2021. In addition, the Company is required to pay a final payment fee of 6.5% of the principal amount extended on the date of repayment of the Term Loans, which is being accreted and amortized into interest expense using the effective interest rate method over the term of the loan.

The Company may prepay all, but not less than all, of the loaned amount subject to a prepayment fee of 3.0% of the outstanding principal if prepaid prior to the first anniversary of the effective date of the Loan Agreement, 2.0% if prepaid on or after the first anniversary, but prior to the second anniversary, or 1.0%, if prepaid on or after the second anniversary but prior to the applicable maturity date. As security for its obligations under the Loan Agreement, the Company granted the Bank a first priority security interest on substantially all of the Company’s assets except its intellectual property and subject to certain other exceptions.

The Loan Agreement contains customary representations and warranties, events of default (including an event of default upon the occurrence of a material impairment on the Bank’s security interest over the collateral, and a material adverse change of the Company) and affirmative and negative covenants, including, among others, covenants that limit or restrict the Company’s ability to incur indebtedness, grant liens, merge or consolidate, dispose of assets, make investments, make acquisitions, enter into certain transactions with affiliates, engage in any new line of business, pay dividends or make distributions, or repurchase stock, in each case subject to certain exceptions. Upon the occurrence and during the continuance of an event of default, a default interest rate will apply that is 5.0% above the otherwise applicable interest rate.

In connection with the Loan Agreement, the Company issued a warrant to the Bank to purchase 50,411 of the Company’s common shares at a price per share of $2.43. The Bank will receive additional common shares exercisable pursuant to the warrant in connection with the second and third tranches, if and when advanced by the Bank. In no event will the number of common shares issuable pursuant to the exercise of the warrant exceed 108,023 in the aggregate. The warrant is immediately exercisable, has a 10-year term, contains a cashless exercise provision, and is classified in equity. The relative fair value of the warrant was $100.

The initial tranche proceeds of $7,000 were allocated based on the relative fair values of the debt instrument and the warrant instrument. The fair value of the warrant and the closing costs were recorded as debt discounts and are being amortized using the effective interest rate method over the term of the loan. The Company determined the effective interest rate on the initial tranche of the loan to be 9.25%. Amortization of the debt discount was $11 for the year ended December 31, 2017.

Interest expense was $24 for the year ended December 31, 2017.

The outstanding loan and unamortized debt discount balances are as follows:

	December 31,
	2017
Term loan	$	7,000
Less: unamortized discount on loan		(203	)
Less: current portion		(700	)
Accrued portion of final payment fee		7
Loan payable, long-term	$	6,104

Scheduled principal payments on outstanding debt, excluding the final payment fee of $455, as of December 31, 2017, are as follows:

2018	$	700
2019		2,800
2020		2,800
2021		700
Total	$	7,000

Share Capital

12 Months Ended

Dec. 31, 2017

Stockholders Equity Note [Abstract]

Share Capital

9.	Share capital:

(a)

Financing:

On September 13, 2016, the Company completed an underwritten public offering of 3,450,000 of its common shares at a public offering price of $7.50 per common share. The Company received approximately $24.3 million of proceeds, net of underwriting discounts and commissions but before offering expenses.

(b)

Authorized share capital:

The Company’s authorized share capital consists of an unlimited number of common and preferred shares without par value.

(c)

Stock-based compensation:

On June 25, 2014, the shareholders of the Company approved the 2014 Equity Incentive Plan (the “2014 Plan”) which permits the grant of stock-based compensation awards to directors, officers, employees and consultants of the Company. The Company’s pre-existing stock option plan (the “Amended and Restated Stock Option Plan”) was limited to the granting of stock options as equity incentive awards whereas the 2014 Plan also allows for the issuance of restricted shares, restricted share units, share appreciation rights and performance shares. The 2014 Plan replaced the Amended and Restated Stock Option Plan. No further options will be granted under the Company’s Amended and Restated Stock Option Plan.

The Amended and Restated Stock Option Plan provided for the grant of options for the purchase of common shares to directors, officers, employees and consultants prior to the Company’s initial public offering (“IPO”). The options granted under the Amended and Restated Stock Option Plan vest on a graduated basis over a four-year period or less and each option’s maximum term is ten years. The Amended and Restated Stock Option Plan will continue to govern the options granted thereunder.

Under the 2014 Plan, options granted generally vest on a graduated basis over a four-year period or less. The exercise price of the options is determined by the Board but must at least be equal to the fair market value of the common shares on the date of grant. Options may be exercised over a maximum term of ten years. As of December 31, 2017, a total of 30,847 stock options remain to be granted under the 2014 Plan. The number of common shares available for issuance under the 2014 Plan was increased by 700,000 in January 2018 as approved by the Board in accordance with the terms of the 2014 Plan.

Summary of stock option activity is as follows:

	Number of			Weighted Average Exercise Price				Aggregate
	Options			CAD $		U.S. $		Intrinsic Value
Outstanding, January 1, 2015		1,484,218			4.88		4.20		15,551
Granted		529,288			18.73		14.67
Exercised		(270,254	)		4.66		3.65		2,426
Forfeited, cancelled or expired		(21,780	)		11.21		8.78
Outstanding, December 31, 2015		1,721,472			9.62		6.95		1,880
Granted		323,794			9.79		7.39
Exercised		(121,292	)		3.67		2.77		568
Forfeited, cancelled or expired		(13,151	)		14.98		11.31
Outstanding, December 31, 2016		1,910,823			9.84		7.32		4,464
Granted		620,950			8.69		6.69
Exercised⁽¹⁾		(71,006	)		3.72		2.86		108
Forfeited, cancelled or expired		(120,862	)		9.06		6.98
Outstanding, December 31, 2017		2,339,905			9.32		7.41		159
Exercisable, December 31, 2017		1,439,301			8.91		7.08		159

(1)	During the year ended December 31, 2017, 63,425 (2016 – 47,413) stock options were exercised for the same number of common shares in exchange for cash. In the same period, the Company issued 4,405 (2016 – 47,841) common shares for the cashless exercise of 7,581 (2016 – 73,879) stock options.

The following table summarizes the stock options outstanding and exercisable at December 31, 2017:

	Options Outstanding								Options Exercisable
Range of Exercise Prices	Number of Options Outstanding		Weighted Average Remaining Contractual Life		Weighted Average Exercise Price				Number of Options Exercisable		Weighted Average Exercise Price
U.S. $			(years)		CAD $		U.S. $				CAD $		U.S. $
$2.12 - $2.95		227,725		5.05		2.67		2.13		226,675		2.67		2.12
$2.96 - $3.04		514,021		2.22		3.74		2.97		514,021		3.74		2.97
$3.05 - $7.44		273,400		9.36		5.25		4.18		30,515		8.73		6.94
$7.45 - $7.73		310,825		8.09		9.52		7.57		158,605		9.53		7.58
$7.74 - $8.49		458,936		8.83		10.46		8.32		52,106		9.84		7.82
$8.50 - $17.70		226,608		6.44		12.11		9.63		210,494		11.81		9.39
$17.71 - $21.82		328,390		7.21		22.34		17.77		246,885		22.34		17.77
		2,339,905		6.51		9.32		7.41		1,439,301		8.91		7.08

At December 31, 2017, there were 1,439,301 options exercisable with a weighted average remaining contractual life as at December 31, 2017 of 5.04 years.

A summary of the Company’s non-vested stock option activity and related information for the year ended December 31, 2017 is as follows:

	Number of Options			Weighted Average Grant Date Fair Value
				CAD $		USD $
Non-vested, January 1, 2017		618,811			9.58		7.13
Granted		620,950			6.51		5.02
Vested		(274,580	)		9.68		7.45
Forfeited and cancelled		(64,577	)		7.46		5.74
Non-vested, December 31, 2017		900,604			7.12		5.66

The aggregate fair value of options vested during the year ended December 31, 2017 was $2,047 (2016 – $3,220, 2015 – $999).

The fair value of stock options at the date of grant is estimated using the Black-Scholes option-pricing model which requires multiple subjective inputs. The risk-free interest rate of the options is based on the U.S. Treasury yield curve in effect at the date of grant for a term similar to the expected term of the option. Prior to the Company’s IPO in November 2014, the Company’s shares did not have a readily available market; therefore, the Company lacks company-specific historical and implied volatility information. Consequently, the expected volatility of stock options was estimated based on a combination of the Company’s available historical volatility information and historical volatility analysis of peers that were similar to the Company with respect to industry, stage of life cycle, size, and financial leverage. Expected life assumptions are based on the Company’s historical data. The dividend yield is based on the fact that the Company has never paid cash dividends and has no present intention to pay cash dividends. Forfeitures are recognized as they occur.

The weighted-average option pricing assumptions are as follows:

	Years ended December 31
	2017			2016			2015
Average risk-free interest rate		2.35	%		1.58	%		1.75	%
Expected volatility		80	%		75	%		75	%
Average expected term (in years)		7.37			6.22			6.23
Expected dividend yield		0.00	%		0.00	%		0.00	%
Weighted average fair value of options granted	$	5.02		$	4.94		$	9.83

Stock-based compensation expense is classified in the consolidated statements of operations and comprehensive income (loss) as follows:

	Years ended December 31,
	2017		2016		2015
Research and development	$	985	$	874	$	624
General and administrative		1,251		1,287		3,105
	$	2,236	$	2,161	$	3,729

As of December 31, 2017, the unrecognized stock-based compensation cost related to the non-vested stock options was $4,251, which is expected to be recognized over a weighted-average period of 2.37 years.

Concentrations of Market Risk

12 Months Ended

Dec. 31, 2017

Risks And Uncertainties [Abstract]

Concentration of market risk

10.	Concentrations of market risk:

(a)

Foreign currency risk:

At December 31, 2017, the Company had U.S. dollar denominated cash and cash equivalents and marketable securities of $28,028 (December 31, 2016 – $35,859) and Canadian denominated cash and cash equivalents and marketable securities of CAD$19,619 (December 31, 2016 – CAD$37,980).

The Company faces foreign currency exchange rate risk in part, as a result of entering into transactions denominated in currencies other than U.S. dollars, particularly those denominated in Canadian dollars. The Company also holds non-U.S. dollar denominated cash and cash equivalents, marketable securities, accounts receivable and accounts payable, which are denominated in Canadian dollars.

Changes in foreign currency exchange rates can create significant foreign exchange gains or losses to the Company. The Company’s current foreign currency risk is with the Canadian dollar, as a majority of non-U.S. dollar denominated expenses are denominated in Canadian dollars and a significant portion of cash and cash equivalents and marketable securities are held in Canadian dollars. To limit the Company’s exposure to volatility in currency markets, management estimates anticipated expenses that will be denominated in Canadian and U.S. dollars and then purchases a corresponding amount of Canadian or U.S. dollars at the current spot rate. Once these estimated expense amounts are acquired, the Company does not hedge its exposure and thus assumes the risk of future gains or losses on the amounts of Canadian dollars held.

(b)

Interest Rate Risk:

At December 31, 2017, the Company had cash and cash equivalents and marketable securities of $43,667. The Company’s interest rate risk is primarily attributable to its cash and cash equivalents and marketable securities. The Company believes that it does not have any material exposure to changes in the fair value of these assets as a result of changes in interest rates due to the short term nature of cash and cash equivalents and marketable securities. The Company does not enter into investments for trading or speculative purposes and has not used any derivative financial instruments to manage interest rate exposure.

The Company had a total outstanding loan balance of $7,000 as of December 31, 2017, of which $700 was due within 12 months. The interest rate on borrowings under the Loan Agreement with the Bank accrues at a floating per annum rate of 0.5% above the prime rate.

Collaboration Agreements

12 Months Ended

Dec. 31, 2017

Organization Consolidation And Presentation Of Financial Statements [Abstract]

Collaboration agreements

11.	Collaboration agreements:

The Company has entered into a number of collaboration agreements with multiple deliverables under which it may have received non-refundable upfront payments. The Company generally recognizes revenue from non-refundable upfront payments ratably over the term of its estimated period of performance of research under its collaboration agreements in the event that such arrangements represent a single unit of accounting.

The collaborations may also include contractual milestone payments, which relate to the achievement of pre-specified research, development, regulatory and commercialization events. The milestone events coincide with the progression of product candidates from research and development, to regulatory approval and through to commercialization. The process of successfully discovering a new product candidate, having it selected by the collaborator for development and having it approved and ultimately sold for a profit is highly uncertain. As such, the milestone payments that the Company may earn from its collaborators involve a significant degree of risk to achieve.

Research and development milestones in the Company’s collaboration agreements may include the following types of events:

•

completion of pre-clinical research and development work leading to selection of product candidates;

•

initiation of Phase 1, Phase 2 or Phase 3 clinical trials; and

•

achievement of certain other scientific or development events.

Regulatory milestone payments may include the following types of events:

•

filing of regulatory applications for marketing approval in the U.S., Europe or Japan, including investigational new drug (“IND”) applications and new drug applications (“NDA”); and

•

marketing approval in a major market, such as the U.S., Europe or Japan.

Commercialization milestone payments may include payments triggered by annual product sales that achieve pre-specified thresholds.

(a)

Teva Pharmaceutical Industries Ltd. (“Teva Pharmaceutical”) collaborative development and license agreement:

In December 2012, the Company entered into a collaborative development and license agreement with Teva Pharmaceutical, through its subsidiary, Ivax International GmbH, pursuant to which the Company granted Teva Pharmaceutical an exclusive worldwide license to develop and commercialize certain products, including TV-45070 (formerly XEN402). On March 7, 2018, the Company entered into an agreement to terminate the collaborative development and license agreement, see subsequent event note 16. Under the terms of the original agreement, Teva Pharmaceutical paid the Company an upfront fee of $41,000. Teva Pharmaceutical funded all development costs with respect to the licensed products. In addition, Teva Pharmaceutical provided funding to the Company for certain of the Company’s full-time equivalents (“FTEs”) performing the research collaboration plan. The Company identified several deliverables under the agreement with Teva Pharmaceutical, including exclusive licenses to compounds and non-exclusive licenses to companion diagnostic products, a commitment to participate in a joint steering committee and research and development services to be performed by the Company on behalf of Teva Pharmaceutical. The Company concluded that the licenses did not have stand-alone value to Teva Pharmaceutical without the Company’s technical expertise and joint steering committee participation during the initial three-year period; therefore, the Company recognized the upfront payment as revenue ratably over the three-year period ended December 31, 2015.

(b)

Genentech collaborative research and license agreement:

In December 2011, the Company entered into a collaborative research and license agreement with Genentech and its affiliate, F. Hoffman-La Roche Ltd. (“Roche”) to discover and develop small and large molecules that selectively inhibit the Nav1.7 sodium channel and companion diagnostics for the potential treatment of pain. Pursuant to this agreement, the Company granted Genentech a worldwide exclusive license to develop and commercialize compounds directed to Nav1.7 and products incorporating such compounds for all uses. The Company also granted Genentech a worldwide non-exclusive license to diagnostic products for the purpose of developing or commercializing such compounds.

Under the terms of the agreement, Genentech paid the Company an upfront fee of $10,000. Genentech provided funding to the Company for certain of the Company’s FTEs performing the research collaboration plan. The Company identified several deliverables under the agreement with Genentech, including exclusive licenses to compounds and non-exclusive licenses to diagnostic products, a commitment to participate in a joint steering committee and research and development services to be performed by the Company on behalf of Genentech. The Company concluded that the licenses did not have stand-alone value to Genentech without the Company’s technical expertise and joint steering committee participation during the initial three year period; therefore, the Company recognized the upfront payment as revenue ratably over the three-year period ended December 22, 2014.

The Company is eligible to receive pre-commercial and commercial milestone payments with respect to the licensed products totaling up to an additional $613,000, comprised of up to $45,500 in pre-clinical and clinical milestone payments, up to $387,500 in regulatory milestone payments, and up to $180,000 in sales-based milestone payments for multiple products and indications. In addition, the Company is eligible to receive royalties based on net sales of the licensed products, which range from a mid single-digit percentage to ten percent for small-molecule inhibitors for the timeframe that such products are covered by the licensed patents and a low single-digit percentage thereafter until the date that is ten years after first commercial sale on a country-by-country basis, plus a low single-digit percentage for large-molecule inhibitors of Nav1.7 for a period of ten years from first commercial sale on a country-by-country basis. The Company believes that the potential milestone payments for pre-clinical, clinical and regulatory milestones under this agreement are substantive and at risk at inception of this agreement, and, as such, expects that these future milestone payments will be recognized as revenue in the period that each milestone is achieved. In the year ended December 31, 2017, no milestone payments have been recognized (2016 – $nil; 2015 – $nil).

The Company believes that the potential sales-based milestone payments under this agreement are not substantive as the Company does not expect to contribute effort to their achievement and expects such sales-based milestones will generally be achieved after the period of substantial involvement under the collaboration. Therefore, the Company expects that future sales-based contingent consideration milestone payments will be recognized as revenue when such milestones are achieved, assuming all other revenue recognition criteria are met. To date, no such milestone payments have been recognized.

In March 2014, the Company entered into a new agreement with Genentech for pain genetics, with a focus on identifying genetic targets associated with rare phenotypes where individuals have an inability to perceive pain or where individuals have non-precipitated spontaneous severe pain. Pursuant to the terms of this agreement, any intellectual property arising out of the collaboration is jointly owned by the Company and Genentech. The Company also granted Genentech a time-limited, exclusive right of first negotiation on a target-by-target basis to form joint drug discovery collaborations. Under the terms of this agreement, Genentech paid an upfront payment of $1,500. The Company is eligible to receive additional milestone payments totaling up to $1,500.

The Company identified several deliverables under this agreement with Genentech, including non-exclusive licenses to certain intellectual property controlled by the Company, a commitment to participate in a joint steering committee and collaborative research services to be performed by the Company. The Company concluded that the licenses did not have stand-alone value to Genentech without the Company’s technical expertise and joint steering committee participation during the initial two year period; therefore, the Company recognized the upfront payment as revenue ratably over the two-year period ended March 18, 2016.

The Company believes that the potential milestone payments under this agreement are substantive and at risk at inception of this agreement, and, as such, expects that these future milestone payments will be recognized as revenue in the period that each milestone is achieved. In the year ended December 31, 2017, a $250 milestone payment has been recognized (2016 – $nil; 2015 – $250).

Pursuant to the terms of the Company’s agreement with the Memorial University of Newfoundland, the Company must pay to the Memorial University of Newfoundland certain milestone payments, a single-digit percentage of net sales for pain products the Company sells directly and a single-digit percentage of royalties received for sales of pain products by Genentech.

The following table is a summary of the revenue recognized from the Company’s collaborations for each of the years ended December 31, 2017, 2016 and 2015.

	Year Ended December 31,
	2017		2016		2015
Teva:
Recognition of upfront payment	$	—	$	—	$	10,897
Research funding		59		116		112
Genentech:
Recognition of upfront payment		—		157		725
Research funding		—		1,494		3,589
Milestone payments		250		—		250
Total collaboration revenue	$	309	$	1,767	$	15,573

Commitments and Contingencies

12 Months Ended

Dec. 31, 2017

Commitments And Contingencies Disclosure [Abstract]

Commitments and Contingencies

12.	Commitments and contingencies:

(a)

Lease commitments:

The Company entered into an amended lease agreement for research laboratories and office space in Burnaby, British Columbia, Canada for a 120-month term from April 1, 2012 to March 31, 2022, which included an element of free rent and tenant inducement that is amortized over the term of the lease.

Lease expense for the year ended December 31, 2017 was $1,079 (2016 – $936, 2015 – $917). Future minimum annual lease payments under existing operating lease commitments are as follows:

Year ending December 31:
2018		1,225
2019		1,227
2020		1,229
2021		1,162
2022		279
Total	$	5,122

(b)

Priority access agreement with Medpace Inc. (“Medpace”):

In August 2015, the Company entered into a priority access agreement with Medpace for the provision of certain clinical development services. Under the terms of the agreement, the Company has committed to using Medpace non-exclusively for clinical development services over the five year term of the agreement. In consideration for priority access to Medpace resources and preferred service rates, the Company has committed to $7,000 of services over the term of the agreement, $3,000 of which was paid in the year ended December 31, 2015. Of the amounts paid by the Company in 2015 in connection with the priority access agreement, an aggregate of $2,770 has been recorded as expenses to date for services rendered, $nil has been classified as current prepaid expenses (2016 – $392) and $230 has been classified as long-term prepaid expenses (2016 – $408) for the provision of future services as at December 31, 2017.

(c)

License, manufacture and supply agreement:

In March 2017, the Company entered into a license, manufacture and supply agreement with a pharmaceutical contract manufacturing organization for the access and use of certain regulatory documents as well as for the manufacture and supply of clinical and commercial drug product to support the development of XEN007. Under the terms of the agreement, the Company paid an upfront fee of $500 CAD and will be required to pay a low single-digit percentage royalty on net sales of any products developed and commercialized under the agreement.

(d)

Asset purchase agreement with 1st Order Pharmaceuticals, Inc. (“1st Order”):

In April 2017, the Company acquired XEN1101 (previously known as 1OP2198) from 1st Order pursuant to an asset purchase agreement. 1st Order previously acquired 1OP2198 from an affiliate of Valeant Pharmaceuticals International, Inc. (“Valeant”), and the Company has assumed certain financial responsibilities under that agreement. Under the terms of the agreement, the Company paid an upfront fee of $350 and milestone payments in 2017 totaling $700, which was expensed as research and development. Future potential payments to both 1st Order and Valeant include $1,000 in clinical development milestones, up to $13,000 in regulatory milestones, and up to approximately $33,600 in sales-based and other milestones, which includes a $1,500 milestone that may be payable pre-commercially, plus a mid-to-high single-digit percentage royalty on commercial sales.

(e)

License agreement

In July 2017, the Company entered into a license agreement with a pharmaceutical company for the access and use of certain regulatory documents to support the development of XEN007. Under the terms of the agreement, the Company paid an upfront fee of $1,000, which was expensed as research and development. Future potential payments include $2,000 in clinical development milestones, up to $7,000 in regulatory milestones, plus a low-to-mid single-digit percentage royalty on net sales of any products developed and commercialized under the agreement.

(f)

Guarantees and indemnifications:

The Company has entered into license and research agreements with third parties that include indemnification provisions that are customary in the industry. These indemnification provisions generally require the Company to compensate the other party for certain damages and costs incurred as a result of third party claims or damages arising from these transactions.

The maximum amount of potential future indemnification is unlimited; however, the Company currently holds commercial and product liability insurance. This insurance limits the Company’s exposure and may enable it to recover a portion of any future amounts paid. Historically, the Company has not made any indemnification payments under such agreements and the Company believes that the fair value of these indemnification obligations is minimal. Accordingly, the Company has not recognized any liabilities relating to these obligations for any period presented.

Income Taxes

12 Months Ended

Dec. 31, 2017

Income Tax Disclosure [Abstract]

Income Taxes

13.	Income taxes:

Income tax (recovery) expense varies from the amounts that would be computed by applying the expected Canadian and provincial statutory income tax rate of 26% (2016 – 26%, 2015 – 26%) to loss before income taxes as shown in the following table:

	2017			2016			2015
Computed recoveries at Canadian federal and provincial tax rates	$	(8,000	)	$	(5,980	)	$	(4,095	)
Change in valuation allowance		9,210			6,897			2,482
Investment tax credits earned		(1,393	)		(1,500	)		(1,220	)
Tax attributes expired/utilized		683			617			2,851
Non-deductible expenditures		594			569			977
Financing fees in equity		—			(531	)		—
Effect of tax rate increases		(1,444	)		—			—
Other		350			(72	)		(995	)
Income tax (recovery) expense	$	—		$	—		$	—

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 Company’s net deferred income tax assets are as follows:

	2017			2016
Deferred income tax assets
Scientific research and experimental development pool	$	25,056		$	22,823
Investment tax credits		22,872			22,483
Non-capital losses		13,645			7,800
Depreciable assets		5,360			4,163
Deferred financing fees		578			1,020
Other		114			126
Less - valuation allowance		(67,625	)		(58,415	)
Net deferred income tax assets	$	—		$	—

The realization of deferred income tax assets is dependent upon the generation of sufficient taxable income during future periods in which the temporary differences are expected to reverse. The valuation allowance is reviewed on a quarterly basis and if the assessment of the “more likely than not” criteria changes, the valuation allowance is adjusted accordingly. A full valuation allowance continues to be applied against deferred income tax assets as the Company has assessed that the realization of such assets does not meet the “more likely than not” criteria.

At December 31, 2017, the Company has unclaimed tax deductions for scientific research and experimental development expenditures of $92,799 (2016 – $87,781) with no expiry.

At December 31, 2017, the Company has $21,066 (2016 – $20,160) of investment tax credits available to offset federal taxes payable and $7,560 (2016 – $7,624) of provincial tax credits available to offset provincial taxes payable in the future.

At December 31, 2017, the Company has non-capital losses, net of uncertain tax positions, carried forward for tax purposes, which are available to reduce taxable income of future years of approximately $50,536 (2016 – $29,999).

The investment tax credits and loss carry forwards expire over various years to 2037.

As of December 31, 2017, the total amount of the Company’s unrecognized tax benefits of uncertain tax positions were $6,350 (2016 – $6,350). If recognized in future periods, the unrecognized tax benefits would affect the Company’s effective tax rate. The Company recognizes potential accrued interest and penalties related to unrecognized tax benefits within the income tax provision. Interest and penalties have not been accrued at December 31, 2017 as none would be owing on the unrecognized tax benefits due to the availability of non-capital losses to shelter any potential taxable income arising thereon.

The Company does not currently expect any significant increases or decreases to these unrecognized tax benefits within 12 months of the reporting date.

The Company files income tax returns in Canada and the United States, the jurisdictions in which the Company believes that it is subject to tax. In jurisdictions in which the Company does not believe it is subject to tax and therefore does not file income tax returns, the Company can provide no certainty that tax authorities in those jurisdictions will not subject one or more tax years (since the inception of the Company) to examination. Further, while the statute of limitations in each jurisdiction where an income tax return has been filed generally limits the examination period, as a result of loss carry-forwards, the limitation period for examination generally does not expire until several years after the loss carry-forwards are utilized. Other than routine audits by tax authorities for tax credits and tax refunds that the Company claims, the Company is not aware of any other material income tax examination currently in progress by any taxing jurisdiction. Tax years ranging from 2002 to 2016 remain subject to Canadian income tax examinations.

Related Parties

12 Months Ended

Dec. 31, 2017

Related Parties

14.	Related Parties:

Dr. August J. Troendle, an officer and director of Medpace, which provides clinical development services to the Company, was a beneficial owner of more than 5% of the Company’s common shares during a portion of 2016. The Company incurred $3,097 of clinical development service fees under its priority access agreement and a master services agreement with Medpace for the year ended December 31, 2016 (2015 – $922). Additionally, the Company has recorded $1,010 of prepaid expenses as of December 31, 2016 (December 31, 2015 – $2,314) for future clinical development services under such agreements with Medpace.

Selected Quarterly Consolidated Financial Data (Unaudited)

12 Months Ended

Dec. 31, 2017

Quarterly Financial Information Disclosure [Abstract]

Selected Quarterly Consolidated Financial Data (Unaudited)

15.	Selected quarterly consolidated financial data (unaudited):

The following table presents certain unaudited quarterly consolidated financial information for the years ended December 31, 2017 and 2016 (in thousands of U.S. dollars except per share amounts). This information reflects all normal recurring adjustments, which are, in the opinion of management, necessary for a fair statement of the results of the interim periods.

	Three Months Ended
	March 31, 2017			June 30, 2017			September 30, 2017			December 31, 2017
Revenue	$	16		$	15		$	264		$	16
Loss from operations		(7,987	)		(7,893	)		(8,644	)		(8,051	)
Net loss		(7,517	)		(7,380	)		(7,742	)		(8,065	)
Basic net loss per common share	$	(0.42	)	$	(0.41	)	$	(0.43	)	$	(0.45	)
Diluted net loss per common share	$	(0.43	)	$	(0.41	)	$	(0.43	)	$	(0.45	)

	Three Months Ended
	March 31, 2016			June 30, 2016			September 30, 2016			December 31, 2016
Revenue	$	601		$	413		$	413		$	376
Loss from operations		(5,658	)		(6,366	)		(7,331	)		(5,462	)
Net loss		(3,263	)		(6,016	)		(7,714	)		(6,004	)
Basic and diluted net loss per common share	$	(0.23	)	$	(0.42	)	$	(0.51	)	$	(0.34	)

Subsequent Event

12 Months Ended

Dec. 31, 2017

Subsequent Events [Abstract]

Subsequent Event

16.	Subsequent event:

On March 7, 2018, the Company and Teva Pharmaceuticals International GmbH and Teva Canada Limited (together “Teva”), entered into a termination agreement terminating by mutual agreement the collaborative development and license agreement dated December 7, 2012, as amended.

Pursuant to the termination agreement and subject to receipt by us of an order from the Ontario Securities Commission (“OSC”), Teva has agreed to transfer and assign 1,000,000 common shares of the Company held by Teva Canada Limited to the Company for cancellation. Teva will also return, license or assign to the Company certain intellectual property including certain patent rights. The termination agreement requires the Company to pay a low single-digit percentage royalty to Teva based on net sales of approved products, if any, resulting from any continued development and commercialization of TV-45070 by the Company during the period that assigned or licensed patents cover such products. Teva will also transfer regulatory filings related to TV-45070 to the Company.

The termination agreement will become effective on the date specified by the Company in a written notice to Teva. The effective date will be after the date that the Company receives the OSC order granting the Company exemptive relief from the requirements related to issuer bids under applicable Canadian securities laws in connection with the transfer and assignment to the Company by Teva Canada of the 1,000,000 common shares and not earlier than 10 business days from the date that a press release announcing the termination agreement is issued by the Company. The Company has made an application to the OSC for the OSC order and expects the effective date to be on or about March 22, 2018.

Significant Accounting Policies (Policies)

12 Months Ended

Dec. 31, 2017

Accounting Policies [Abstract]

Use of estimates

(a)

Use of estimates:

Cash and cash equivalents

(b)

Cash and cash equivalents:

Marketable Securities

(c)

Marketable securities:

Intellectual Property

(d)

Intellectual Property

The costs incurred in establishing and maintaining patents for intellectual property developed internally are expensed in the period incurred.

Property, plant and equipment

(e)

Property, plant and equipment:

Property, plant and equipment are stated at cost less accumulated depreciation and/or accumulated impairment losses, if any. Repairs and maintenance costs are expensed in the period incurred.

Property, plant and equipment are amortized over their estimated useful lives using the straight-line method based on the following rates:

Asset		Rate
Research equipment		5 years
Office furniture and equipment		5 years
Computer equipment		3 years
Leasehold improvements		Over the lesser of lease term or estimated useful life

Impairment of long-lived assets

(f)

Impairment of long-lived assets:

Concentration of credit risk and of significant customers

(g)

Concentration of credit risk and of significant customers:

Collaborators whose collaboration research and development revenue accounted for 10% or more of total revenues were as follows:

	Year ended December 31,
	2017		2016		2015
Genentech	$	250	$	1,651	$	4,563
Teva		59		116		11,010

Financial instruments and fair value

(h)

Financial instruments and fair value:

We measure certain financial instruments and other items at fair value.

•

Level 1 - Unadjusted quoted prices in active markets for identical instruments.

•

Revenue recognition

(i)

Revenue recognition:

The Company generates revenue primarily through collaboration agreements.

Research and development costs

(j)

Research and development costs:

Research and development costs are expensed in the period incurred.

Stock-based compensation

(k)

Stock-based compensation:

The Company grants stock options to employees, directors and officers pursuant to a stock option plan described in note 9c.

(l)

Liability classified stock options:

Foreign currency translation

(m)

Foreign currency translation:

Income taxes

(n)

Income taxes:

Deferred tenant inducements

(o)

Deferred tenant inducements:

Segment and geographic information

(p)

Segment and geographic information:

Comparative figures

(q)

Comparative figures:

Certain comparative figures have been reclassified to conform to the consolidated financial statement presentation adopted for the current year.

Significant Accounting Policies (Tables)

12 Months Ended

Dec. 31, 2017

Property Plant and Equipment Estimated Useful Lives

Property, plant and equipment are amortized over their estimated useful lives using the straight-line method based on the following rates:

Asset		Rate
Research equipment		5 years
Office furniture and equipment		5 years
Computer equipment		3 years
Leasehold improvements		Over the lesser of lease term or estimated useful life

Collaboration Research And Development Revenue [Member]

Revenue Recognized From Collaborations

Collaborators whose collaboration research and development revenue accounted for 10% or more of total revenues were as follows

	Year ended December 31,
	2017		2016		2015
Genentech	$	250	$	1,651	$	4,563
Teva		59		116		11,010

Net Income (Loss) Per Common Share (Tables)

12 Months Ended

Dec. 31, 2017

Earnings Per Share [Abstract]

Reconciliation of the Numerators and Denominators of Basic and Diluted Net Loss Per Common Share

The following is a reconciliation of the numerators and denominators of basic and diluted net loss per common share:

	Year Ended December 31,
	2017			2016			2015
Numerator:
Net loss used to compute net loss per common share:
Basic	$	(30,704	)	$	(22,997	)	$	(15,752	)
Adjustment for change in fair value of liability classified stock options		(187	)		—			—
Diluted	$	(30,891	)	$	(22,997	)	$	(15,752	)
Denominator:
Weighted average number of common shares:
Basic		17,985,061			15,493,474			14,281,837
Adjustment for dilutive effect of stock options		16,698			—			—
Diluted		18,001,759			15,493,474			14,281,837
Net loss per common share - basic	$	(1.71	)	$	(1.48	)	$	(1.10	)
Net loss per common share - diluted	$	(1.72	)	$	(1.48	)	$	(1.10	)

Property, Plant and Equipment (Tables)

12 Months Ended

Dec. 31, 2017

Property Plant And Equipment [Abstract]

Summary of Property, Plant and Equipment

Property, plant and equipment consisted of the following:

	December 31,
	2017			2016
Research equipment	$	6,984		$	6,789
Office furniture and equipment		1,043			1,045
Computer equipment		2,311			2,283
Leasehold improvements		6,370			6,370
Less: accumulated depreciation and amortization		(15,638	)		(15,083	)
Net book value	$	1,070		$	1,404

Accounts Payable and Accrued Expenses (Tables)

12 Months Ended

Dec. 31, 2017

Payables And Accruals [Abstract]

Accounts Payable and Accrued Expenses

Accounts payable and accrued expenses consisted of the following:

	December 31,
	2017		2016
Trade payables	$	1,253	$	1,463
Employee compensation, benefits, and related accruals		1,017		872
Consulting and contracted research		817		1,029
Professional fees		252		93
Other		44		129
Total	$	3,383	$	3,586

Term Loan (Tables)

12 Months Ended

Dec. 31, 2017

Debt Disclosure [Abstract]

Schedule of Outstanding Loan and Unamortized Debt Discount Balances

The outstanding loan and unamortized debt discount balances are as follows:

	December 31,
	2017
Term loan	$	7,000
Less: unamortized discount on loan		(203	)
Less: current portion		(700	)
Accrued portion of final payment fee		7
Loan payable, long-term	$	6,104

Schedule of Principal Payments on Outstanding Debt

Scheduled principal payments on outstanding debt, excluding the final payment fee of $455, as of December 31, 2017, are as follows:

2018	$	700
2019		2,800
2020		2,800
2021		700
Total	$	7,000

Share Capital (Tables)

12 Months Ended

Dec. 31, 2017

Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]

Stock Option Activity

Summary of stock option activity is as follows:

	Number of			Weighted Average Exercise Price				Aggregate
	Options			CAD $		U.S. $		Intrinsic Value
Outstanding, January 1, 2015		1,484,218			4.88		4.20		15,551
Granted		529,288			18.73		14.67
Exercised		(270,254	)		4.66		3.65		2,426
Forfeited, cancelled or expired		(21,780	)		11.21		8.78
Outstanding, December 31, 2015		1,721,472			9.62		6.95		1,880
Granted		323,794			9.79		7.39
Exercised		(121,292	)		3.67		2.77		568
Forfeited, cancelled or expired		(13,151	)		14.98		11.31
Outstanding, December 31, 2016		1,910,823			9.84		7.32		4,464
Granted		620,950			8.69		6.69
Exercised⁽¹⁾		(71,006	)		3.72		2.86		108
Forfeited, cancelled or expired		(120,862	)		9.06		6.98
Outstanding, December 31, 2017		2,339,905			9.32		7.41		159
Exercisable, December 31, 2017		1,439,301			8.91		7.08		159

(1)	During the year ended December 31, 2017, 63,425 (2016 – 47,413) stock options were exercised for the same number of common shares in exchange for cash. In the same period, the Company issued 4,405 (2016 – 47,841) common shares for the cashless exercise of 7,581 (2016 – 73,879) stock options.

Summary of Stock Option Outstanding and Exercisable

The following table summarizes the stock options outstanding and exercisable at December 31, 2017:

	Options Outstanding								Options Exercisable
Range of Exercise Prices	Number of Options Outstanding		Weighted Average Remaining Contractual Life		Weighted Average Exercise Price				Number of Options Exercisable		Weighted Average Exercise Price
U.S. $			(years)		CAD $		U.S. $				CAD $		U.S. $
$2.12 - $2.95		227,725		5.05		2.67		2.13		226,675		2.67		2.12
$2.96 - $3.04		514,021		2.22		3.74		2.97		514,021		3.74		2.97
$3.05 - $7.44		273,400		9.36		5.25		4.18		30,515		8.73		6.94
$7.45 - $7.73		310,825		8.09		9.52		7.57		158,605		9.53		7.58
$7.74 - $8.49		458,936		8.83		10.46		8.32		52,106		9.84		7.82
$8.50 - $17.70		226,608		6.44		12.11		9.63		210,494		11.81		9.39
$17.71 - $21.82		328,390		7.21		22.34		17.77		246,885		22.34		17.77
		2,339,905		6.51		9.32		7.41		1,439,301		8.91		7.08

Schedule of Nonvested Stock Option Activity

A summary of the Company’s non-vested stock option activity and related information for the year ended December 31, 2017 is as follows:

	Number of Options			Weighted Average Grant Date Fair Value
				CAD $		USD $
Non-vested, January 1, 2017		618,811			9.58		7.13
Granted		620,950			6.51		5.02
Vested		(274,580	)		9.68		7.45
Forfeited and cancelled		(64,577	)		7.46		5.74
Non-vested, December 31, 2017		900,604			7.12		5.66

Fair Value Assumptions for Stock Options

The weighted-average option pricing assumptions are as follows:

	Years ended December 31
	2017			2016			2015
Average risk-free interest rate		2.35	%		1.58	%		1.75	%
Expected volatility		80	%		75	%		75	%
Average expected term (in years)		7.37			6.22			6.23
Expected dividend yield		0.00	%		0.00	%		0.00	%
Weighted average fair value of options granted	$	5.02		$	4.94		$	9.83

Stock Based Compensation Expenses

Stock-based compensation expense is classified in the consolidated statements of operations and comprehensive income (loss) as follows:

	Years ended December 31,
	2017		2016		2015
Research and development	$	985	$	874	$	624
General and administrative		1,251		1,287		3,105
	$	2,236	$	2,161	$	3,729

Collaboration Agreements (Tables)

12 Months Ended

Dec. 31, 2017

Organization Consolidation And Presentation Of Financial Statements [Abstract]

Schedule of Revenues from Collaborations

The following table is a summary of the revenue recognized from the Company’s collaborations for each of the years ended December 31, 2017, 2016 and 2015.

	Year Ended December 31,
	2017		2016		2015
Teva:
Recognition of upfront payment	$	—	$	—	$	10,897
Research funding		59		116		112
Genentech:
Recognition of upfront payment		—		157		725
Research funding		—		1,494		3,589
Milestone payments		250		—		250
Total collaboration revenue	$	309	$	1,767	$	15,573

Commitments and Contingencies (Tables)

12 Months Ended

Dec. 31, 2017

Commitments And Contingencies Disclosure [Abstract]

Future Minimum Annual Lease Payments for Operating Leases

Future minimum annual lease payments under existing operating lease commitments are as follows:

Year ending December 31:
2018		1,225
2019		1,227
2020		1,229
2021		1,162
2022		279
Total	$	5,122

Income Taxes (Tables)

12 Months Ended

Dec. 31, 2017

Income Tax Disclosure [Abstract]

Schedule of Income Tax (Recovery) Expense

	2017			2016			2015
Computed recoveries at Canadian federal and provincial tax rates	$	(8,000	)	$	(5,980	)	$	(4,095	)
Change in valuation allowance		9,210			6,897			2,482
Investment tax credits earned		(1,393	)		(1,500	)		(1,220	)
Tax attributes expired/utilized		683			617			2,851
Non-deductible expenditures		594			569			977
Financing fees in equity		—			(531	)		—
Effect of tax rate increases		(1,444	)		—			—
Other		350			(72	)		(995	)
Income tax (recovery) expense	$	—		$	—		$	—

Schedule of Net Deferred Income Tax Assets

The significant components of the Company’s net deferred income tax assets are as follows:

	2017			2016
Deferred income tax assets
Scientific research and experimental development pool	$	25,056		$	22,823
Investment tax credits		22,872			22,483
Non-capital losses		13,645			7,800
Depreciable assets		5,360			4,163
Deferred financing fees		578			1,020
Other		114			126
Less - valuation allowance		(67,625	)		(58,415	)
Net deferred income tax assets	$	—		$	—

Selected Quarterly Consolidated Financial Data (Unaudited) (Tables)

12 Months Ended

Dec. 31, 2017

Quarterly Financial Information Disclosure [Abstract]

Selected Quarterly Consolidated Financial Data

	Three Months Ended
	March 31, 2017			June 30, 2017			September 30, 2017			December 31, 2017
Revenue	$	16		$	15		$	264		$	16
Loss from operations		(7,987	)		(7,893	)		(8,644	)		(8,051	)
Net loss		(7,517	)		(7,380	)		(7,742	)		(8,065	)
Basic net loss per common share	$	(0.42	)	$	(0.41	)	$	(0.43	)	$	(0.45	)
Diluted net loss per common share	$	(0.43	)	$	(0.41	)	$	(0.43	)	$	(0.45	)

	Three Months Ended
	March 31, 2016			June 30, 2016			September 30, 2016			December 31, 2016
Revenue	$	601		$	413		$	413		$	376
Loss from operations		(5,658	)		(6,366	)		(7,331	)		(5,462	)
Net loss		(3,263	)		(6,016	)		(7,714	)		(6,004	)
Basic and diluted net loss per common share	$	(0.23	)	$	(0.42	)	$	(0.51	)	$	(0.34	)

Nature of the business (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
Nature of the business (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Accumulated deficit	$ 173,388				$ 142,681				$ 173,388	$ 142,681
Net loss	$ 8,065	$ 7,742	$ 7,380	$ 7,517	$ 6,004	$ 7,714	$ 6,016	$ 3,263	$ 30,704	$ 22,997	$ 15,752

Significant Accounting Policies - Property Plant and Equipment Estimated Useful Lives (Details)	12 Months Ended
	Dec. 31, 2017
Research Equipment [Member]
Property Plant And Equipment [Line Items]
Property, Plant and Equipment, Useful Life	5 years
Office Furniture and Equipment [Member]
Property Plant And Equipment [Line Items]
Property, Plant and Equipment, Useful Life	5 years
Computer Equipment [Member]
Property Plant And Equipment [Line Items]
Property, Plant and Equipment, Useful Life	3 years
Leasehold Improvements [Member]
Property Plant And Equipment [Line Items]
Property, Plant and Equipment, Estimated Useful Lives	Over the lesser of lease term or estimated useful life

Significant Accounting Policies (Details)	12 Months Ended
Significant Accounting Policies (Details)	Dec. 31, 2017 USD ($) Segment	Dec. 31, 2016 USD ($)
Significant Accounting Policies [Line Items]
Impairment of Long-Lived Assets	$ 0	$ 0
Number of operating segment \| Segment	1
Account Payable and Accrued Expenses [Member]
Significant Accounting Policies [Line Items]
Liability classified stock options	$ 37,000	$ 261,000
Minimum [Member] \| Revenue from Rights Concentration Risk [Member] \| Collaboration Research And Development Revenue [Member]
Significant Accounting Policies [Line Items]
Collaborative Research And Development Revenue	10.00%

Significant Accounting Policies - Revenue Recognized from Collaborations (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Collaboration revenue	$ 309	$ 1,767	$ 15,573
Genentech [Member] \| Collaborative Arrangement [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Collaboration revenue	250	1,651	4,563
Teva [Member] \| Collaborative Arrangement [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Collaboration revenue	$ 59	$ 116	$ 11,010

Net Income (Loss) Per Common Share (Details)	12 Months Ended
Net Income (Loss) Per Common Share (Details)	Dec. 31, 2017 shares
Stock Options and Warrants [Member]
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Anti-dilutive shares excluded from the calculation of income per common share	2,172,034

Net Income (Loss) Per Common Share - Reconciliation of the Numerators and Denominators of Basic and Diluted Net Loss Per Common Share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended				12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Net loss used to compute net loss per common share:
Basic					$ (30,704)	$ (22,997)	$ (15,752)
Adjustment for change in fair value of liability classified stock options					(187)
Diluted					$ (30,891)	$ (22,997)	$ (15,752)
Weighted average number of common shares:
Basic					17,985,061	15,493,474	14,281,837
Adjustment for dilutive effect of stock options					16,698
Diluted					18,001,759	15,493,474	14,281,837
Net loss per common share - basic	$ (0.45)	$ (0.43)	$ (0.41)	$ (0.42)	$ (1.71)	$ (1.48)	$ (1.10)
Net loss per common share - diluted	$ (0.45)	$ (0.43)	$ (0.41)	$ (0.43)	$ (1.72)	$ (1.48)	$ (1.10)

Property, Plant and Equipment - Summary of Property, Plant and Equipment (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Property Plant And Equipment [Line Items]
Less: accumulated depreciation and amortization	$ (15,638)	$ (15,083)
Net book value	1,070	1,404
Research Equipment [Member]
Property Plant And Equipment [Line Items]
Property, plant and equipment	6,984	6,789
Office Furniture and Equipment [Member]
Property Plant And Equipment [Line Items]
Property, plant and equipment	1,043	1,045
Computer Equipment [Member]
Property Plant And Equipment [Line Items]
Property, plant and equipment	2,311	2,283
Leasehold Improvements [Member]
Property Plant And Equipment [Line Items]
Property, plant and equipment	$ 6,370	$ 6,370

Accounts Payable and Accrued Expenses - Accounts Payable and Accrued Expenses (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Payables And Accruals [Abstract]
Trade payables	$ 1,253	$ 1,463
Employee compensation, benefits, and related accruals	1,017	872
Consulting and contracted research	817	1,029
Professional fees	252	93
Other	44	129
Total	$ 3,383	$ 3,586

Term Loan (Details)		12 Months Ended
Term Loan (Details)	Dec. 18, 2017 USD ($) Tranche $ / shares shares	Dec. 31, 2017 USD ($)
Debt Instrument [Line Items]
Initial tranche amount of debt instrument		$ 7,000,000
Amortization of the debt discount		11,000
Loan Agreement [Member] \| Bank [Member]
Debt Instrument [Line Items]
Aggregate principal amount of debt instrument	$ 15,000,000
Loan Agreement [Member] \| Bank [Member] \| Term Loans [Member]
Debt Instrument [Line Items]
Debt instrument, agreement date	Dec. 18, 2017
Number of tranches \| Tranche	3
Debt instrument, payment commencing period	2018-01
Debt instrument, final payment fee percentage	6.50%
Debt instrument default interest payment above normal interest rate	5.00%
Warrant exercisable term	10 years
Fair value of warrant	$ 100,000
Amortization of the debt discount		11,000
Interest expense		24,000
Final payment fee		455,000
Loan Agreement [Member] \| Bank [Member] \| Term Loans [Member] \| Common Stock [Member]
Debt Instrument [Line Items]
Issued a warrant to purchase common stock \| shares	50,411
Warrant exercise price per share \| $ / shares	$ 2.43
Maximum issuable exercise of warrants to purchase common stock \| shares	108,023
Loan Agreement [Member] \| Bank [Member] \| Term Loans [Member] \| Prior to First Anniversary [Member]
Debt Instrument [Line Items]
Debt instrument, prepayment fee payable on outstanding principal, in percentage	3.00%
Loan Agreement [Member] \| Bank [Member] \| Term Loans [Member] \| After First Anniversary, but Prior to Second Anniversary [Member]
Debt Instrument [Line Items]
Debt instrument, prepayment fee payable on outstanding principal, in percentage	2.00%
Loan Agreement [Member] \| Bank [Member] \| Term Loans [Member] \| After Second Anniversary [Member]
Debt Instrument [Line Items]
Debt instrument, prepayment fee payable on outstanding principal, in percentage	1.00%
Loan Agreement [Member] \| Bank [Member] \| Term Loans [Member] \| Prime Rate [Member]
Debt Instrument [Line Items]
Debt instrument, floating interest rate	0.50%
Loan Agreement [Member] \| Bank [Member] \| Term Loans [Member] \| Initial Tranche [Member]
Debt Instrument [Line Items]
Initial tranche amount of debt instrument	$ 7,000,000	$ 7,000,000
Debt instrument, interest only payment end date	Sep. 30, 2018
Debt instrument principal repayment period	30 months
Debt instrument, maturity date	Mar. 31, 2021
Effective interest rate on initial tranche of debt instrument		9.25%
Loan Agreement [Member] \| Bank [Member] \| Term Loans [Member] \| Tranche Two and Tranche Three [Member]
Debt Instrument [Line Items]
Debt instrument, remaining borrowing capacity	$ 8,000,000
Loan Agreement [Member] \| Bank [Member] \| Term Loans [Member] \| Second Tranche [Member]
Debt Instrument [Line Items]
Debt instrument, interest only payment end date	Mar. 31, 2019
Debt instrument principal repayment period	24 months
Debt instrument, maturity date	Mar. 31, 2021
Loan Agreement [Member] \| Bank [Member] \| Term Loans [Member] \| Third Tranche [Member]
Debt Instrument [Line Items]
Debt instrument, interest only payment end date	Sep. 30, 2019
Debt instrument principal repayment period	24 months
Debt instrument, maturity date	Sep. 30, 2021

Term Loan - Schedule of Outstanding Loan and Unamortized Debt Discount Balances (Details) $ in Thousands	Dec. 31, 2017 USD ($)
Debt Instrument [Line Items]
Term loan	$ 7,000
Less: current portion	(700)
Loan payable, long-term	6,104
Term Loans [Member]
Debt Instrument [Line Items]
Term loan	7,000
Less: unamortized discount on loan	(203)
Less: current portion	(700)
Accrued portion of final payment fee	7
Loan payable, long-term	$ 6,104

Term Loan - Schedule of Principal Payments on Outstanding Debt (Details) $ in Thousands	Dec. 31, 2017 USD ($)
Debt Disclosure [Abstract]
2018	$ 700
2019	2,800
2020	2,800
2021	700
Term loan	$ 7,000

Share Capital (Details) - USD ($) $ / shares in Units, $ in Thousands			1 Months Ended	12 Months Ended
	Sep. 13, 2016	Jun. 25, 2014	Jan. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Proceeds from net of underwriting discounts and commissions Before offering expenses					$ 23,832
Number of Options Exercisable				1,439,301
Options Exercisable Weighted Average Remaining Contractual Life in Years				5 years 14 days
Aggregate fair value of options vested				$ 2,047	$ 3,220	$ 999
Unrecognized stock-based compensation cost				$ 4,251
Unrecognized stock-based compensation expected to be recognized over a period				2 years 4 months 13 days
Amended And Restated Stock Option Plan [Member] \| Maximum [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Options exercise term				10 years
Options vesting period				4 years
Two Thousand Fourteen Plan [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of Options, Granted				30,847
Two Thousand Fourteen Plan [Member] \| Subsequent Event [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Common stock reserved for issuance			700,000
Two Thousand Fourteen Plan [Member] \| Maximum [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Options exercise term		10 years
Options vesting period		4 years
Underwritten Public Offering [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Issuance of common shares, net of issuance costs (in Shares)	3,450,000
Common share price (in Dollars per share)	$ 7.50
Proceeds from net of underwriting discounts and commissions Before offering expenses	$ 24,300

Share Capital - Stock Option Activity (Details)
$ / shares in Units, $ in Thousands

12 Months Ended

Dec. 31, 2017

USD ($)

$ / shares

Dec. 31, 2017

USD ($)

$ / shares

CAD / shares

Dec. 31, 2016

USD ($)

$ / shares

Dec. 31, 2016

CAD / shares

Dec. 31, 2015

USD ($)

$ / shares

Dec. 31, 2015

CAD / shares

Dec. 31, 2017

CAD / shares

Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]

Number of Options Outstanding, Beginning balance

1,910,823

1,721,472

1,484,218

Number of Options, Granted

620,950

323,794

529,288

Number of Options, Exercised

(71,006)

^[1]

(121,292)

(270,254)

Number of Options, Forfeited, cancelled or expired

(120,862)

(13,151)

(21,780)

Number of Options Outstanding, Ending balance

2,339,905

1,910,823

1,721,472

Number of Options Exercisable

1,439,301

Weighted Average Exercise Price Outstanding, Beginning balance | (per share)

$ 7.32

CAD 9.84

$ 6.95

CAD 9.62

$ 4.20

CAD 4.88

Weighted Average Exercise Price, Granted | (per share)

6.69

8.69

7.39

9.79

14.67

18.73

Weighted Average Exercise Price, Exercised | (per share)

2.86

^[1]

3.72

^[1]

2.77

3.67

3.65

4.66

Weighted Average Exercise Price, Forfeited, cancelled and expired | (per share)

6.98

9.06

11.31

14.98

8.78

11.21

Weighted Average Exercise Price Outstanding, Ending balance | (per share)

7.41

CAD 9.32

$ 7.32

CAD 9.84

$ 6.95

CAD 9.62

Weighted Average Exercise Price, Exercisable Ending balance | (per share)

$ 7.08

CAD 7.08

CAD 8.91

Aggregate Intrinsic Value, Outstanding, Beginning balance | $

$ 4,464

$ 1,880

$ 15,551

Aggregate Intrinsic Value, Exercised | $

108

^[1]

568

2,426

Aggregate Intrinsic Value, Outstanding, Ending balance | $

159

$ 4,464

$ 1,880

Aggregate Intrinsic Value, Exercisable, Ending balance | $

$ 159

CAD 159

[1]	During the year ended December 31, 2017, 63,425 (2016 – 47,413) stock options were exercised for the same number of common shares in exchange for cash. In the same period, the Company issued 4,405 (2016 – 47,841) common shares for the cashless exercise of 7,581 (2016 – 73,879) stock options.

Share Capital - Stock Option Activity (Parenthetical) (Details) - shares	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Stock Options exercised for Number of Common Shares for cash	63,425	47,413
Common stock issued for cashless exercise	4,405	47,841
Cashless exercise of stock options	7,581	73,879

Share Capital - Summary of Stock Option Outstanding and Exercisable (Details)	12 Months Ended
	Dec. 31, 2017 $ / shares shares	Dec. 31, 2017 CAD / shares shares	Dec. 31, 2016 $ / shares shares	Dec. 31, 2016 CAD / shares shares	Dec. 31, 2015 $ / shares shares	Dec. 31, 2015 CAD / shares shares	Dec. 31, 2014 $ / shares shares	Dec. 31, 2014 CAD / shares shares
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of Options Outstanding	2,339,905	2,339,905	1,910,823	1,910,823	1,721,472	1,721,472	1,484,218	1,484,218
Options Outstanding Weighted Average Remaining Contractual Life in Years	6 years 6 months 3 days
Options Outstanding, Weighted Average Exercise Price \| (per share)	$ 7.41	CAD 9.32	$ 7.32	CAD 9.84	$ 6.95	CAD 9.62	$ 4.20	CAD 4.88
Number of Options Exercisable	1,439,301	1,439,301
Options exercisable, Weighted Average Exercise Price \| (per share)	$ 7.08	CAD 8.91
Range of Exercise Prices - $2.12 - $2.95 [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Exercise price range, lower range limit \| $ / shares	2.12
Exercise price range, upper range limit \| $ / shares	$ 2.95
Number of Options Outstanding	227,725	227,725
Options Outstanding Weighted Average Remaining Contractual Life in Years	5 years 18 days
Options Outstanding, Weighted Average Exercise Price \| (per share)	$ 2.13	CAD 2.67
Number of Options Exercisable	226,675	226,675
Options exercisable, Weighted Average Exercise Price \| (per share)	$ 2.12	CAD 2.67
Range of Exercise Prices - $2.96 - $3.04 [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Exercise price range, lower range limit \| $ / shares	2.96
Exercise price range, upper range limit \| $ / shares	$ 3.04
Number of Options Outstanding	514,021	514,021
Options Outstanding Weighted Average Remaining Contractual Life in Years	2 years 2 months 19 days
Options Outstanding, Weighted Average Exercise Price \| (per share)	$ 2.97	CAD 3.74
Number of Options Exercisable	514,021	514,021
Options exercisable, Weighted Average Exercise Price \| (per share)	$ 2.97	CAD 3.74
Range of Exercise Prices - $3.05 - $7.44 [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Exercise price range, lower range limit \| $ / shares	3.05
Exercise price range, upper range limit \| $ / shares	$ 7.44
Number of Options Outstanding	273,400	273,400
Options Outstanding Weighted Average Remaining Contractual Life in Years	9 years 4 months 9 days
Options Outstanding, Weighted Average Exercise Price \| (per share)	$ 4.18	CAD 5.25
Number of Options Exercisable	30,515	30,515
Options exercisable, Weighted Average Exercise Price \| (per share)	$ 6.94	CAD 8.73
Range of Exercise Prices - $7.45 - $7.73 [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Exercise price range, lower range limit \| $ / shares	7.45
Exercise price range, upper range limit \| $ / shares	$ 7.73
Number of Options Outstanding	310,825	310,825
Options Outstanding Weighted Average Remaining Contractual Life in Years	8 years 1 month 2 days
Options Outstanding, Weighted Average Exercise Price \| (per share)	$ 7.57	CAD 9.52
Number of Options Exercisable	158,605	158,605
Options exercisable, Weighted Average Exercise Price \| (per share)	$ 7.58	CAD 9.53
Range of Exercise Prices - $7.74 - $8.49 [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Exercise price range, lower range limit \| $ / shares	7.74
Exercise price range, upper range limit \| $ / shares	$ 8.49
Number of Options Outstanding	458,936	458,936
Options Outstanding Weighted Average Remaining Contractual Life in Years	8 years 9 months 29 days
Options Outstanding, Weighted Average Exercise Price \| (per share)	$ 8.32	CAD 10.46
Number of Options Exercisable	52,106	52,106
Options exercisable, Weighted Average Exercise Price \| (per share)	$ 7.82	CAD 9.84
Range of Exercise Prices - $8.50 - $17.70 [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Exercise price range, lower range limit \| $ / shares	8.50
Exercise price range, upper range limit \| $ / shares	$ 17.70
Number of Options Outstanding	226,608	226,608
Options Outstanding Weighted Average Remaining Contractual Life in Years	6 years 5 months 8 days
Options Outstanding, Weighted Average Exercise Price \| (per share)	$ 9.63	CAD 12.11
Number of Options Exercisable	210,494	210,494
Options exercisable, Weighted Average Exercise Price \| (per share)	$ 9.39	CAD 11.81
Range of Exercise Prices - $17.71 - $21.82 [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Exercise price range, lower range limit \| $ / shares	17.71
Exercise price range, upper range limit \| $ / shares	$ 21.82
Number of Options Outstanding	328,390	328,390
Options Outstanding Weighted Average Remaining Contractual Life in Years	7 years 2 months 15 days
Options Outstanding, Weighted Average Exercise Price \| (per share)	$ 17.77	CAD 22.34
Number of Options Exercisable	246,885	246,885
Options exercisable, Weighted Average Exercise Price \| (per share)	$ 17.77	CAD 22.34

Share Capital - Summary of Non-Vested Stock Option Activity (Details)	12 Months Ended
	Dec. 31, 2017 $ / shares shares	Dec. 31, 2017 CAD / shares shares	Dec. 31, 2016 $ / shares shares	Dec. 31, 2016 CAD / shares shares	Dec. 31, 2015 $ / shares shares
Sharebased Compensation Arrangement By Sharebased Payment Award Options Nonvested Number Of Shares Roll Forward
Number of Options, Non-vested, Beginning balance	618,811	618,811
Number of Options, Granted	620,950	620,950	323,794	323,794	529,288
Number of Options, Vested	(274,580)	(274,580)
Number of Options, Forfeited and cancelled	(64,577)	(64,577)
Number of Options, Non-vested, Ending balance	900,604	900,604	618,811	618,811
Weighted Average Grant Date Fair Value, Non-vested, Beginning balance \| (per share)	$ 7.13	CAD 9.58
Weighted Average Grant Date Fair Value, Granted \| (per share)	5.02	6.51	$ 4.94		$ 9.83
Weighted Average Grant Date Fair Value, Vested \| (per share)	7.45	9.68
Weighted Average Grant Date Fair Value, Forfeited and cancelled \| (per share)	5.74	7.46
Weighted Average Grant Date Fair Value, Non-vested, Ending balance \| (per share)	$ 5.66	CAD 7.12	$ 7.13	CAD 9.58

Share Capital - Fair Value Assumptions for Stock Options (Details)	12 Months Ended
	Dec. 31, 2017 $ / shares	Dec. 31, 2017 CAD / shares	Dec. 31, 2016 $ / shares	Dec. 31, 2015 $ / shares
Fair Value Assumptions For Stock Options [Abstract]
Average risk-free interest rate	2.35%	2.35%	1.58%	1.75%
Expected volatility	80.00%	80.00%	75.00%	75.00%
Average expected term (in years)	7 years 4 months 13 days	7 years 4 months 13 days	6 years 2 months 19 days	6 years 2 months 23 days
Expected dividend yield	0.00%	0.00%	0.00%	0.00%
Weighted average fair value of options granted \| (per share)	$ 5.02	CAD 6.51	$ 4.94	$ 9.83

Share Capital - Stock Based Compensation Expenses (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock-based compensation	$ 2,236	$ 2,161	$ 3,729
Research and development [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock-based compensation	985	874	624
General and administrative [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock-based compensation	$ 1,251	$ 1,287	$ 3,105

Concentrations of Market Risk (Details) CAD in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2017 USD ($)	Dec. 31, 2017 CAD	Dec. 31, 2016 USD ($)	Dec. 31, 2016 CAD
Concentration Risk [Line Items]
Total outstanding loan balance, due within 12 months	$ 700
Interest Rate Risk [Member]
Concentration Risk [Line Items]
Cash and cash equivalents and marketable securities	$ 43,667
Interest rate risk, description	The Company does not enter into investments for trading or speculative purposes and has not used any derivative financial instruments to manage interest rate exposure. A 10% change in interest rates during any of the periods presented would not have had a material impact on the Company’s consolidated financial statements.
Total outstanding loan balance	$ 7,000
Total outstanding loan balance, due within 12 months	$ 700
Interest Rate Risk [Member] \| Prime Rate [Member] \| Loan Agreement [Member] \| Bank [Member]
Concentration Risk [Line Items]
Percentage of floating rate above prime rate	0.50%
Foreign Currency Exchange Risk [Member]
Concentration Risk [Line Items]
Cash and cash equivalents and marketable securities	$ 28,028	CAD 19,619	$ 35,859	CAD 37,980

Collaboration Agreements (Details) - USD ($)		1 Months Ended	12 Months Ended
Collaboration Agreements (Details) - USD ($)	Mar. 07, 2018	Mar. 31, 2014	Dec. 31, 2017	Dec. 31, 2015	Dec. 31, 2012	Dec. 31, 2011
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Upfront payment performance description			the Company recognized the upfront payment as revenue ratably over the two-year period ended March 18, 2016.
Sales Based Milestone [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Proceeds from milestone payments			$ 0
Teva Pharmaceutical [Member] \| TV-45070 [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Proceeds from upfront fee					$ 41,000,000
Teva Pharmaceutical [Member] \| Subsequent Event [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Collaborative development and license agreement termination date	Mar. 07, 2018
Genentech [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Proceeds from upfront fee		$ 1,500,000
Potential Milestone Payments Receivable		$ 1,500,000				$ 613,000,000
Proceeds from milestone payments			250,000	$ 250,000
Genentech [Member] \| Pre-clinical And Clinical Milestone [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Potential Milestone Payments Receivable						45,500,000
Genentech [Member] \| Regulatory Milestone [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Potential Milestone Payments Receivable						387,500,000
Genentech [Member] \| Sales Based Milestone [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Potential Milestone Payments Receivable						180,000,000
Genentech [Member] \| Pre-clinical Clinical and Regulatory Milestones [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Proceeds from milestone payments			$ 0
Genentech [Member] \| GDC-0276 [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Proceeds from upfront fee						$ 10,000,000

Collaboration Agreements - Revenue Recognized from Collaborations (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Collaboration revenue	$ 309	$ 1,767	$ 15,573
Teva Pharmaceutical [Member] \| Collaborative Arrangement [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Collaboration revenue	59	116	11,010
Teva Pharmaceutical [Member] \| Recognition of Upfront Payment [Member] \| Collaborative Arrangement [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Collaboration revenue			10,897
Teva Pharmaceutical [Member] \| Research Funding [Member] \| Collaborative Arrangement [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Collaboration revenue	59	116	112
Genentech [Member] \| Collaborative Arrangement [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Collaboration revenue	250	1,651	4,563
Genentech [Member] \| Recognition of Upfront Payment [Member] \| Collaborative Arrangement [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Collaboration revenue		157	725
Genentech [Member] \| Research Funding [Member] \| Collaborative Arrangement [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Collaboration revenue		$ 1,494	3,589
Genentech [Member] \| Milestone Payments [Member] \| Collaborative Arrangement [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Collaboration revenue	$ 250		$ 250

Commitments and Contingencies (Details) $ in Thousands	1 Months Ended			12 Months Ended
Commitments and Contingencies (Details) $ in Thousands	Jul. 31, 2017 USD ($)	Apr. 30, 2017 USD ($)	Mar. 31, 2017 CAD	Dec. 31, 2017 USD ($)	Dec. 31, 2016 USD ($)	Dec. 31, 2015 USD ($)	Aug. 31, 2015 USD ($)
Commitments and Contingencies [Line Items]
Lease Agreement Description				for a 120-month term from April 1, 2012 to March 31, 2022,
Lease Expiration Date				Mar. 31, 2022
Amended Operating Leases Term				120 months
Operating Leases, Rent Expense				$ 1,079	$ 936	$ 917
Prepaid expenses, long term				230	408
Asset Purchase Agreement [Member] \| 1st Order Pharmaceuticals, Inc. [Member]
Commitments and Contingencies [Line Items]
Upfront fee paid		$ 350
Milestone payments paid				$ 700
Asset Purchase Agreement [Member] \| 1st Order Pharmaceuticals, Inc. and Valeant Pharmaceuticals International, Inc. [Member] \| Clinical Development Milestones [Member]
Commitments and Contingencies [Line Items]
Future potential payments		1,000
Asset Purchase Agreement [Member] \| 1st Order Pharmaceuticals, Inc. and Valeant Pharmaceuticals International, Inc. [Member] \| Regulatory Milestone [Member]
Commitments and Contingencies [Line Items]
Future potential payments		13,000
Asset Purchase Agreement [Member] \| 1st Order Pharmaceuticals, Inc. and Valeant Pharmaceuticals International, Inc. [Member] \| Sales-based and Other Milestones [Member]
Commitments and Contingencies [Line Items]
Future potential payments		33,600
Asset Purchase Agreement [Member] \| 1st Order Pharmaceuticals, Inc. and Valeant Pharmaceuticals International, Inc. [Member] \| Pre-commercial and Single Digit Percentage Royalty on Commercial Sales Milestone [Member]
Commitments and Contingencies [Line Items]
Future potential payments		$ 1,500
License Agreement [Member]
Commitments and Contingencies [Line Items]
Upfront fee paid	$ 1,000
License Agreement [Member] \| Clinical Development Milestones [Member]
Commitments and Contingencies [Line Items]
Future potential payments	2,000
License Agreement [Member] \| Regulatory Milestone [Member] \| Maximum [Member]
Commitments and Contingencies [Line Items]
Future potential payments	$ 7,000
Medpace Clinical Development Service Agreement [Member]
Commitments and Contingencies [Line Items]
Service agreement, term				5 years
Committed service obligation							$ 7,000
Contractual obligation paid						$ 3,000
Expenses for services rendered				$ 2,770
Current prepaid expenses					392
Prepaid expenses, long term				$ 230	$ 408
License, Manufacture and Supply Agreement [Member]
Commitments and Contingencies [Line Items]
Upfront fee paid \| CAD			CAD 500

Commitments and Contingencies - Future Minimum Annual Lease Payments for Operating Leases (Details) $ in Thousands	Dec. 31, 2017 USD ($)
Commitments And Contingencies Disclosure [Abstract]
2018	$ 1,225
2019	1,227
2020	1,229
2021	1,162
2022	279
Total	$ 5,122

Income Taxes (Details) - USD ($) $ in Thousands	12 Months Ended
Income Taxes (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Tax Credit Carryforward [Line Items]
Income tax (recovery) expense	26.00%	26.00%	26.00%
Unclaimed Tax Deductions Related To Scientific Research And Experimental Development Expenditures	$ 92,799	$ 87,781
Non-capital losses carried forward for tax purposes	$ 50,536	29,999
Tax Credit Carry forward, Expiration Date	Dec. 31, 2037
Unrecognized tax benefits of uncertain tax positions	$ 6,350	6,350
Canada Revenue Agency [Member] \| Latest Tax Year [Member]
Tax Credit Carryforward [Line Items]
Tax year open for income tax examination	2002
Canada Revenue Agency [Member] \| Earliest Tax Year [Member]
Tax Credit Carryforward [Line Items]
Tax year open for income tax examination	2016
Investment Tax credit [Member]
Tax Credit Carryforward [Line Items]
Tax credit available to offset federal taxes payable	$ 21,066	20,160
Provincial Tax Credit [Member]
Tax Credit Carryforward [Line Items]
Tax credit available to offset federal taxes payable	$ 7,560	$ 7,624

Income Taxes - Income Tax (Recovery) Expense (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Income Tax Disclosure [Abstract]
Computed recoveries at Canadian federal and provincial tax rates	$ (8,000)	$ (5,980)	$ (4,095)
Change in valuation allowance	9,210	6,897	2,482
Investment tax credits earned	(1,393)	(1,500)	(1,220)
Tax attributes expired/utilized	683	617	2,851
Non-deductible expenditures	594	569	977
Financing fees in equity		(531)
Effect of tax rate increases	(1,444)
Other	$ 350	$ (72)	$ (995)

Income Taxes - Net Deferred Income Tax Assets (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Deferred income tax assets
Scientific research and experimental development pool	$ 25,056	$ 22,823
Investment tax credits	22,872	22,483
Non-capital losses	13,645	7,800
Depreciable assets	5,360	4,163
Deferred financing fees	578	1,020
Other	114	126
Less - valuation allowance	$ (67,625)	$ (58,415)

Related Parties (Details) - Medpace Clinical Development Service Agreement [Member] - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015
Related Party Transaction [Line Items]
Clinical development service fees to related parties	$ 3,097	$ 922
Prepaid Expenses	$ 1,010	$ 2,314
Dr. August J. Troendle, Officer and Director [Member] \| Minimum [Member]
Related Party Transaction [Line Items]
Percentage of ownership	5.00%

Selected Quarterly Consolidated Financial Data (Unaudited) - Quarterly Consolidated Financial Information for Interim Periods (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Quarterly Financial Information Disclosure [Abstract]
Revenue	$ 16	$ 264	$ 15	$ 16	$ 376	$ 413	$ 413	$ 601	$ 311	$ 1,803	$ 15,577
Loss from operations	(8,051)	(8,644)	(7,893)	(7,987)	(5,462)	(7,331)	(6,366)	(5,658)	(32,575)	(24,817)	(9,361)
Net loss	$ (8,065)	$ (7,742)	$ (7,380)	$ (7,517)	$ (6,004)	$ (7,714)	$ (6,016)	$ (3,263)	$ (30,704)	$ (22,997)	$ (15,752)
Net loss per common share - basic	$ (0.45)	$ (0.43)	$ (0.41)	$ (0.42)					$ (1.71)	$ (1.48)	$ (1.10)
Net loss per common share - diluted	$ (0.45)	$ (0.43)	$ (0.41)	$ (0.43)					$ (1.72)	$ (1.48)	$ (1.10)
Basic and diluted net loss per common share					$ (0.34)	$ (0.51)	$ (0.42)	$ (0.23)

Subsequent Event (Details) - Subsequent Event [Member]	Mar. 07, 2018 shares
Teva [Member]
Subsequent Event [Line Items]
Collaborative development and license agreement termination date	Mar. 07, 2018
Teva Canada Limited [Member]
Subsequent Event [Line Items]
Number of common shares agreed to transfer and assign for cancellation	1,000,000

Basis of presentation (Details)	12 Months Ended
Basis of presentation (Details)	Dec. 31, 2017
Xenon Pharmaceuticals USA Inc. [Member]
Basis of Presentation [Line Items]
Date of incorporation	Dec. 02, 2016