Document And Entity Information	9 Months Ended
Document And Entity Information	Sep. 30, 2015	Nov. 02, 2015
Document And Entity Information [Abstract]
Entity Registrant Name	Xenon Pharmaceuticals Inc.
Document Type	10-Q
Trading Symbol	XENE
Current Fiscal Year End Date	--12-31
Entity Common Stock, Shares Outstanding		14,376,218
Amendment Flag	false
Entity Central Index Key	0001582313
Entity Filer Category	Non-accelerated Filer
Document Period End Date	Sep. 30, 2015
Document Fiscal Year Focus	2015
Document Fiscal Period Focus	Q3

Balance Sheets (USD $) In Thousands, unless otherwise specified	Sep. 30, 2015	Dec. 31, 2014
Current assets:
Cash and cash equivalents	$ 65,469	$ 72,026
Marketable securities		12,015
Accounts receivable	274	215
Prepaid expenses and other current assets	371	686
Total current assets	66,114	84,942
Property, plant and equipment, net	2,130	2,476
Prepaid expenses, long term (note 7)	1,700
Total assets	69,944	87,418
Current liabilities:
Accounts payable and accrued expenses (note 8)	2,823	2,664
Deferred revenue	2,513	11,622
Total current liabilities	5,336	14,286
Deferred revenue, less current portion		157
Deferred tenant inducements	149	196
Total liabilities	5,485	14,639
Shareholders’ equity:
Common shares, without par value; unlimited shares authorized; issued and outstanding: 14,344,267 (December 31, 2014 - 14,181,333)	148,359	147,157
Additional paid-in capital	32,844	30,346
Accumulated deficit	(115,754)	(103,734)
Accumulated other comprehensive loss	(990)	(990)
Shareholders’ equity	64,459	72,779
Total liabilities and shareholders’ equity	69,944	87,418
Commitments and contingencies (note 11)

Balance Sheets (Parenthetical) (USD $)	9 Months Ended	12 Months Ended
Balance Sheets (Parenthetical) (USD $)	Sep. 30, 2015	Dec. 31, 2014
Statement Of Financial Position [Abstract]
Common shares, Par Value (in Dollars per share)
Common stock, shares authorized	Unlimited	Unlimited
Common shares, Issued	14,344,267	14,181,333
Common shares, Outstanding	14,344,267	14,181,333

Statements of Operations and Comprehensive Income (Loss) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Revenue:
Collaboration revenue (note 10)	$ 4,293	$ 13,192	$ 12,347	$ 23,489
Royalties	1	1	3	3
Revenues	4,294	13,193	12,350	23,492
Operating expenses:
Research and development	3,793	3,216	10,889	8,315
General and administrative	1,321	1,316	8,219	4,106
Total operating expenses	5,114	4,532	19,108	12,421
Income (loss) from operations	(820)	8,661	(6,758)	11,071
Other income (expense):
Interest income	130	138	445	416
Foreign exchange gain (loss)	(3,137)	392	(5,502)	307
Net income (loss)	(3,827)	9,191	(11,815)	11,794
Net income attributable to participating securities		5,596		8,199
Net income (loss) attributable to common shareholders	(3,827)	3,595	(11,815)	3,595
Net income (loss) per common share (note 5):
Basic	$ (0.27)	$ 2.67	$ (0.83)	$ 2.67
Diluted	$ (0.27)	$ 1.69	$ (0.83)	$ 1.71
Weighted-average shares outstanding (note 5):
Basic	14,298,612	1,348,417	14,251,006	1,346,989
Effects of dilutive securities
Stock options		763,949		749,967
Subscription rights		10,400		11,447
Diluted	14,298,612	2,122,766	14,251,006	2,108,403
Other comprehensive income (loss):
Foreign currency translation adjustment		(1,512)		(1,502)
Comprehensive income (loss)	$ (3,827)	$ 7,679	$ (11,815)	$ 10,292

Statement of Shareholders' Equity (Deficit) (USD $)
In Thousands, except Share data

Total

Preferred Stock [Member]

Series A Preferred Stock [Member]

Preferred Stock [Member]

Series B Preferred Stock [Member]

Preferred Stock [Member]

Series E Preferred Stock [Member]

Common Stock [Member]

Additional Paid-in Capital [Member]

Retained Earnings [Member]

Accumulated Other Comprehensive Income (Loss) [Member]

Balance at Dec. 31, 2013

$ (78,372)

$ 2,939

$ 8,683

$ 90,866

$ 6,147

$ 29,722

$ (116,752)

$ 2,511

Balance (in Shares) at Dec. 31, 2013

1,151,468

994,885

4,322,126

1,344,627

Net income (loss)

13,018

Conversion of Series A, B and E convertible preferred shares

102,488

(2,939)

(8,683)

(90,866)

102,488

Conversion of series A, B and E convertible preferred shares (in Shares)

(1,151,468)

(994,885)

(4,322,126)

7,725,924

Issuance of common shares, net of issuance costs

38,373

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

5,095,000

Foreign currency translation adjustment

(3,501)

Stock option compensation expense

760

Issuance of common shares on conversion of subscription rights

124

(124)

Issuance of common shares on conversion of subscription rights (in Shares)

13,365

Issued pursuant to exercise of stock options

(12)

Issued pursuant to exercise of stock options (in Shares)

2,417

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 income (loss)

(11,815)

Stock option compensation expense

1,603

Issued pursuant to exercise of stock options

240

1,202

(757)

(205)

Issued pursuant to exercise of stock options (in Shares)

209,850

^[1]

162,934

Fair value adjustment upon reclassification of stock options

1,652

Balance at Sep. 30, 2015

$ 64,459

$ 148,359

$ 32,844

$ (115,754)

$ (990)

^[2]

Balance (in Shares) at Sep. 30, 2015

14,344,267

[1]	During the nine months ended September 30, 2015, 62,469 stock options were exercised for the same number of common shares for cash. In the same period, the Company issued 100,465 common shares for the cashless exercise of 147,381 stock options.
[2]	At September 30, 2015, 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. See Note 3 – Changes in significant accounting policies.

Statements of Cash Flows (USD $) In Thousands, unless otherwise specified	9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014
Operating activities:
Net income (loss)	$ (11,815)	$ 11,794
Adjustments to reconcile net income (loss) to net cash used in operating activities:
Depreciation and amortization	754	533
Stock-based compensation	3,255	561
Deferred tenant inducements	(47)	(50)
Unrealized foreign exchange loss	5,486	52
Changes in operating assets and liabilities:
Accounts receivable	(61)	267
Prepaid expenses, and other current assets	315	(27)
Prepaid expenses, long term	(1,700)
Accounts payable and accrued expenses	223	614
Deferred revenue	(9,266)	(10,527)
Net cash provided by (used in) operating activities	(12,856)	3,217
Investing activities:
Purchases of property, plant and equipment	(408)	(753)
Purchase of marketable securities		(15,334)
Proceeds from marketable securities	10,745	11,803
Net cash provided by (used in) investing activities	10,337	(4,284)
Financing activities:
Deferred financing fees		(1,305)
Proceeds from issuance of common shares	240	10
Net cash provided by (used in) financing activities	240	(1,295)
Effect of exchange rate changes on cash and cash equivalents	(4,278)	(1,857)
Decrease in cash and cash equivalents	(6,557)	(4,219)
Cash and cash equivalents, beginning of period	72,026	37,950
Cash and cash equivalents, end of period	65,469	33,731
Supplemental disclosures:
Interest received	550	439
Supplemental disclosures of non-cash transactions:
Issuance of common shares on conversion of subscription rights		32
Fair value of options exercised on a cashless basis	$ 544

Nature of the Business

9 Months Ended

Sep. 30, 2015

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 discovering and developing a pipeline of differentiated therapeutics for orphan indications that it intends to commercialize on its own, and for larger market indications that it intends to partner with global pharmaceutical companies.

- Definition

The entire disclosure for organization, consolidation and basis of presentation of financial statements disclosure.

+ References+ Details

Basis of Presentation

9 Months Ended

Sep. 30, 2015

Accounting Policies [Abstract]

Basis of presentation

2.	Basis of presentation:

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

The accompanying unaudited interim financial statements have been prepared in accordance with United States generally accepted accounting principles (“U.S. GAAP”) and pursuant to the rules and regulations of the United States Securities and Exchange Commission (“SEC”) for interim financial information. Accordingly, these financial statements do not include all of the information and footnotes required for complete financial statements and should be read in conjunction with the audited financial statements and notes for the year ended December 31, 2014 and included in the Company’s 2014 Annual Report on Form 10-K filed with the SEC on March 12, 2015.

These unaudited interim financial statements reflect all adjustments, consisting of normal recurring adjustments, which, in the opinion of management, are necessary for a fair presentation of results for the interim periods presented. The results of operations for the three and nine month periods ended September 30, 2015 and 2014 are not necessarily indicative of results that can be expected for a full year. These unaudited interim financial statements follow the same significant accounting policies as those described in the notes to the audited financial statements of the Company included in the Company’s 2014 Annual Report on Form 10-K for the year ended December 31, 2014, with the exception of the policies described in note 3.

Changes in Significant Accounting Policies

9 Months Ended

Sep. 30, 2015

Accounting Changes And Error Corrections [Abstract]

Changes in significant accounting policies

3.	Changes in significant accounting policies:

(a)

Functional Currency:

The Company’s 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 change in functional currency is accounted for prospectively from January 1, 2015 and prior year financial statements have not been restated for the change in functional currency. Past translation gains and losses from the application of the U.S. dollar as the reporting currency while the Canadian dollar was the functional currency are included as part of the cumulative foreign currency translation adjustment, which is reported as a component of shareholders’ equity under accumulated other comprehensive loss.

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 statement of operations and comprehensive income (loss) as foreign exchange gain (loss).

(b)

Liability classified stock options:

The Company granted stock options with exercise prices denominated in Canadian dollars under its Amended and Restated Stock Option Plan to members of its board of directors and certain consultants prior to the Company’s initial public offering (“IPO”) in November 2014. Following the change in functional currency on January 1, 2015, described in note3(a), the options denominated in Canadian dollars that were granted to members of the Company’s board of directors and certain consultants were subject to liability accounting with fair value calculated using the Black-Scholes option-pricing model.

During the three months ended September 30, 2015, the Company modified certain compensation arrangements to be denominated in Canadian dollars. Following this modification, the options denominated in Canadian dollars that were granted to members of the Company’s board of directors and certain consultants are again subject to equity accounting with fair value at the modification date calculated using the Black-Scholes option-pricing model and reclassified to additional paid-in capital. The modified awards will be accounted for as equity awards from the date of modification.

- Definition

The entire disclosure of changes in accounting principles, including adoption of new accounting pronouncements, that describes the new methods, amount and effects on financial statement line items.

+ References

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+ Details

Future Changes in Accounting Policies

9 Months Ended

Sep. 30, 2015

Accounting Changes And Error Corrections [Abstract]

Future changes in accounting policies

4.	Future changes in accounting policies:

In May 2014, the FASB issued amendments 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 amendments stipulate 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. Additional disclosure will also be required about the nature, amount, timing and uncertainty of revenue and cash flows arising from customer contracts, including significant judgments and changes in judgments, and assets recognized from costs incurred to obtain or fulfill a contract. In August 2015, the FASB issued an update deferring the effective date of the new revenue standard by one year. The new guidance would be effective for public entities for fiscal years beginning after December 15, 2017 instead of the originally contemplated effective date of December 15, 2016. The Company is currently evaluating the new guidance to determine the impact it will have on the Company’s financial position, results of operations and cash flows.

In August 2014, the FASB issued amendments requiring management to assess an entity’s ability to continue as a going concern. For each reporting period, management will be required to evaluate whether there are conditions or events that raise substantial doubt about a company’s ability to continue as a going concern within one year from the date the financial statements are issued. These amendments will be effective for public entities for the annual period ending after December 15, 2016, and for annual periods and interim periods thereafter. The adoption of these amendments in fiscal 2017 is not expected to have a material impact on the Company’s financial statements.

Net Income (Loss) Per Common Share

9 Months Ended

Sep. 30, 2015

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) attributable to common shareholders by the weighted average number of common shares outstanding for the period. Diluted net income (loss) per common share is computed by adjusting net income (loss) attributable to common shareholders to reallocate undistributed earnings based on the potential impact of dilutive securities.

Prior to the Company’s IPO, net income (loss) per share was calculated under the two-class method as the Company had outstanding shares that met the definition of participating securities. The two-class method determines net income (loss) per share for each class of common and participating securities according to dividends declared or accumulated and participation rights in undistributed earnings. The two-class method requires income available to common shareholders for the period to be allocated between common and participating securities based upon their respective rights to receive dividends as if all income for the period had been distributed. All of the outstanding redeemable convertible preferred shares converted to common shares upon the consummation of the Company’s IPO.

As the Company reported a net loss attributable to common shareholders for the three and nine months ended September 30, 2015, all stock options were anti-dilutive and were excluded from the diluted weighted average shares outstanding for those periods. For the three and nine months ended September 30, 2014, common shares of 205,182 and 201,411, respectively, were excluded from the calculation of income per common share because their inclusion would be anti-dilutive.

- Definition

The entire disclosure for earnings per share.

+ References+ Details

Fair Value of Financial Instruments

9 Months Ended

Sep. 30, 2015

Fair Value Disclosures [Abstract]

Fair value of financial instruments

6.	Fair value of financial instruments:

U.S. GAAP establishes a fair value hierarchy for inputs to be 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 assets or liabilities that the Company has the ability to access at the balance sheet date.

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.

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.

- Definition

The entire disclosure for the fair value of financial instruments (as defined), including financial assets and financial liabilities (collectively, as defined), and the measurements of those instruments as well as disclosures related to the fair value of non-financial assets and liabilities. Such disclosures about the financial instruments, assets, and liabilities would include: (1) the fair value of the required items together with their carrying amounts (as appropriate); (2) for items for which it is not practicable to estimate fair value, disclosure would include: (a) information pertinent to estimating fair value (including, carrying amount, effective interest rate, and maturity, and (b) the reasons why it is not practicable to estimate fair value; (3) significant concentrations of credit risk including: (a) information about the activity, region, or economic characteristics identifying a concentration, (b) the maximum amount of loss the entity is exposed to based on the gross fair value of the related item, (c) policy for requiring collateral or other security and information as to accessing such collateral or security, and (d) the nature and brief description of such collateral or security; (4) quantitative information about market risks and how such risks are managed; (5) for items measured on both a recurring and nonrecurring basis information regarding the inputs used to develop the fair value measurement; and (6) for items presented in the financial statement for which fair value measurement is elected: (a) information necessary to understand the reasons for the election, (b) discussion of the effect of fair value changes on earnings, (c) a description of [similar groups] items for which the election is made and the relation thereof to the balance sheet, the aggregate carrying value of items included in the balance sheet that are not eligible for the election; (7) all other required (as defined) and desired information.

+ References+ Details

Long Term Prepaid Expenses

9 Months Ended

Sep. 30, 2015

Deferred Costs Capitalized Prepaid And Other Assets Disclosure [Abstract]

Long Term Prepaid Expenses

7.	Long term prepaid expenses:

In August 2015, the Company entered into a priority access agreement with Medpace, Inc. (“Medpace”) for the provision of certain clinical development services. Upon signing of the agreement, the Company prepaid $1,700 for future services to be provided by Medpace (notes 11 and 12).

Accounts Payable and Accrued Expenses

9 Months Ended

Sep. 30, 2015

Payables And Accruals [Abstract]

Accounts payable and accrued expenses

8.	Accounts payable and accrued expenses:

Accounts payable and accrued expenses consisted of the following:

	September 30,		December 31,
	2015		2014
Trade payables	$	817	$	553
Employee compensation, benefits, and related accruals		855		1,077
Consulting and contracted research		945		774
Professional fees		180		180
Other		26		80
Total	$	2,823	$	2,664

Stock Option Plan

9 Months Ended

Sep. 30, 2015

Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]

Stock option plan

9.	Stock option plan:

The following table presents stock option activity for the period:

	Three Months Ended September 30,						Nine Months Ended September 30,
	2015			2014			2015			2014
Outstanding, beginning of period		1,745,018			1,442,741			1,484,218			1,333,099
Granted		4,100			6,273			384,538			163,504
Exercised⁽¹⁾		(110,039	)		(1,028	)		(209,850	)		(1,800	)
Forfeited and expired		(1,905	)		(4,411	)		(21,732	)		(51,228	)
Outstanding, end of period		1,637,174			1,443,575			1,637,174			1,443,575
Exercisable, end of period		1,052,955			1,078,009			1,052,955			1,078,009

⁽¹⁾

During the nine months ended September 30, 2015, 62,469 stock options were exercised for the same number of common shares for cash. In the same period, the Company issued 100,465 common shares for the cashless exercise of 147,381 stock options.

The fair value of each option issued to employees and non-employees is estimated using the Black-Scholes option-pricing model with the following weighted-average assumptions:

	Three Months Ended September 30,						Nine Months Ended September 30,
	2015			2014			2015			2014
Average risk-free interest rate		1.74	%		1.95	%		1.71	%		1.97	%
Average expected term (in years)		6.25			6.25			6.23			6.20
Expected volatility		67	%		74	%		75	%		74	%
Expected dividend yield		0.00	%		0.00	%		0.00	%		0.00	%
Expected forfeiture rate		0.00	%		0.00	%		0.00	%		0.00	%

The weighted-average fair value of options granted during the nine months ended September 30, 2015 was $11.50 (nine months ended September 30, 2014 - $6.58) per option.

- Definition

The entire disclosure for compensation-related costs for equity-based compensation, which may include disclosure of policies, compensation plan details, allocation of equity compensation, incentive distributions, equity-based arrangements to obtain goods and services, deferred compensation arrangements, employee stock ownership plan details and employee stock purchase plan details.

+ References+ Details

Collaboration Agreements

9 Months Ended

Sep. 30, 2015

Organization Consolidation And Presentation Of Financial Statements [Abstract]

Collaboration Agreements

10.	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 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 prespecified 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.

The following table is a summary of the revenue recognized from the Company’s collaborations for the three and nine months ended September 30, 2015 and 2014:

	Three Months Ended September 30,				Nine Months Ended September 30,
	2015		2014		2015		2014
uniQure:
Milestone payment	$	—	$	14	$	—	$	14
Teva:
Recognition of upfront payment		2,940		3,132		8,724		9,252
Research funding		11		84		101		251
Genentech:
Recognition of upfront payment		182		981		542		2,736
Research funding		910		994		2,730		3,249
Milestone payment		250		7,987		250		7,987
Total collaboration revenue	$	4,293	$	13,192	$	12,347	$	23,489

Commitments and Contingencies

9 Months Ended

Sep. 30, 2015

Commitments And Contingencies Disclosure [Abstract]

Commitments and Contingencies

11.	Commitments and contingencies:

(a)

Priority access agreement with 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, $1,700 of which was prepaid upon signing of the agreement (note 7) and an additional $1,300 will be paid during the remainder of 2015.

(b)

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.

- Definition

The entire disclosure for commitments and contingencies.

+ References+ Details

Related Parties

9 Months Ended

Sep. 30, 2015

Related Parties

12.	Related Parties:

Dr. August J. Troendle, an officer and director of Medpace, which provides clinical development services to the Company, is a beneficial owner of more than 5% of the Company’s common shares. The Company incurred $512 and $567 of clinical development service fees to Medpace for the three and nine months ended September 30, 2015, respectively ($nil – three and nine months ended September 30, 2014). Additionally, $512 and $nil was due to Medpace as of September 30, 2015 and December 31, 2014 which is included in accounts payable and accrued expenses.

- Definition

The entire disclosure for related party transactions. Examples of related party transactions include transactions between (a) a parent company and its subsidiary; (b) subsidiaries of a common parent; (c) and entity and its principal owners; and (d) affiliates.

+ References+ Details

Accounts Payable and Accrued Expenses (Tables)

9 Months Ended

Sep. 30, 2015

Payables And Accruals [Abstract]

Accounts Payable and Accrued Expenses

Accounts payable and accrued expenses consisted of the following:

	September 30,		December 31,
	2015		2014
Trade payables	$	817	$	553
Employee compensation, benefits, and related accruals		855		1,077
Consulting and contracted research		945		774
Professional fees		180		180
Other		26		80
Total	$	2,823	$	2,664

Stock Option Plan (Tables)

9 Months Ended

Sep. 30, 2015

Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]

Schedule of Share-based Compensation, Stock Options, Activity

The following table presents stock option activity for the period:

	Three Months Ended September 30,						Nine Months Ended September 30,
	2015			2014			2015			2014
Outstanding, beginning of period		1,745,018			1,442,741			1,484,218			1,333,099
Granted		4,100			6,273			384,538			163,504
Exercised⁽¹⁾		(110,039	)		(1,028	)		(209,850	)		(1,800	)
Forfeited and expired		(1,905	)		(4,411	)		(21,732	)		(51,228	)
Outstanding, end of period		1,637,174			1,443,575			1,637,174			1,443,575
Exercisable, end of period		1,052,955			1,078,009			1,052,955			1,078,009

⁽¹⁾

Schedule of Share-based Payment Award, Stock Options, Valuation Assumptions

The fair value of each option issued to employees and non-employees is estimated using the Black-Scholes option-pricing model with the following weighted-average assumptions:

	Three Months Ended September 30,						Nine Months Ended September 30,
	2015			2014			2015			2014
Average risk-free interest rate		1.74	%		1.95	%		1.71	%		1.97	%
Average expected term (in years)		6.25			6.25			6.23			6.20
Expected volatility		67	%		74	%		75	%		74	%
Expected dividend yield		0.00	%		0.00	%		0.00	%		0.00	%
Expected forfeiture rate		0.00	%		0.00	%		0.00	%		0.00	%

Collaboration Agreements (Tables)

9 Months Ended

Sep. 30, 2015

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 the three and nine months ended September 30, 2015 and 2014:

	Three Months Ended September 30,				Nine Months Ended September 30,
	2015		2014		2015		2014
uniQure:
Milestone payment	$	—	$	14	$	—	$	14
Teva:
Recognition of upfront payment		2,940		3,132		8,724		9,252
Research funding		11		84		101		251
Genentech:
Recognition of upfront payment		182		981		542		2,736
Research funding		910		994		2,730		3,249
Milestone payment		250		7,987		250		7,987
Total collaboration revenue	$	4,293	$	13,192	$	12,347	$	23,489

Net Income (Loss) Per Common Share (Details)	3 Months Ended	9 Months Ended
Net Income (Loss) Per Common Share (Details)	Sep. 30, 2014	Sep. 30, 2014
Earnings Per Share [Abstract]
Anti-dilutive shares excluded from the calculation of income per common share	205,182	201,411

- Definition

Securities (including those issuable pursuant to contingent stock agreements) that could potentially dilute basic earnings per share (EPS) or earnings per unit (EPU) in the future that were not included in the computation of diluted EPS or EPU because to do so would increase EPS or EPU amounts or decrease loss per share or unit amounts for the period presented.

+ References+ Details

Accounts Payable and Accrued Expenses - Accounts Payable and Accrued Expenses (Details) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2015	Dec. 31, 2014
Payables And Accruals [Abstract]
Trade payables	$ 817	$ 553
Employee compensation, benefits, and related accruals	855	1,077
Consulting and contracted research	945	774
Professional fees	180	180
Other	26	80
Total	$ 2,823	$ 2,664

- Definition

Carrying value as of the balance sheet date of obligations incurred through that date and payable arising from transactions not otherwise specified in the taxonomy. Used to reflect the current portion of the liabilities (due within one year or within the normal operating cycle if longer).

+ References+ Details

Stock Option Plan - Stock Option Activity (Details)

3 Months Ended

9 Months Ended

Sep. 30, 2015

Sep. 30, 2014

Sep. 30, 2015

Sep. 30, 2014

Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]

Outstanding, beginning of period

1,745,018

1,442,741

1,484,218

1,333,099

Granted

4,100

6,273

384,538

163,504

Exercised

(110,039)

^[1]

(1,028)

^[1]

(209,850)

^[1]

(1,800)

^[1]

Forfeited and expired

(1,905)

(4,411)

(21,732)

(51,228)

Outstanding, end of period

1,637,174

1,443,575

1,637,174

1,443,575

Exercisable, end of period

1,052,955

1,078,009

1,052,955

1,078,009

[1]	During the nine months ended September 30, 2015, 62,469 stock options were exercised for the same number of common shares for cash. In the same period, the Company issued 100,465 common shares for the cashless exercise of 147,381 stock options.

- Definition

Number of share options (or share units) exercised during the current period.

+ References+ Details

Stock Option Plan - Stock Option Activity (Parenthetical) (Details)	9 Months Ended
	Sep. 30, 2015
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Stock Options exercised for Number of Common Shares for cash	62,469
Common stock issued for cashless exercise	100,465
Cashless exercise of stock options	147,381

Stock Option Plan - Fair Value Assumptions for Stock Options (Details)	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Fair Value Assumptions For Stock Options [Abstract]
Average risk-free interest rate	1.74%	1.95%	1.71%	1.97%
Average expected term (in years)	6 years 3 months	6 years 3 months	6 years 2 months 23 days	6 years 2 months 12 days
Expected volatility	67.00%	74.00%	75.00%	74.00%
Expected dividend yield	0.00%	0.00%	0.00%	0.00%
Expected forfeiture rate	0.00%	0.00%	0.00%	0.00%

Collaboration Agreements - Revenue Recognized from Collaborations (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Collaboration Revenue [Line Items]
Collaboration revenue	$ 4,293	$ 13,192	$ 12,347	$ 23,489
UniQure [Member] \| Milestone Payment [Member] \| Collaborative Arrangement [Member]
Collaboration Revenue [Line Items]
Collaboration revenue		14		14
Teva [Member] \| Recognition of Upfront Payment [Member] \| Collaborative Arrangement [Member]
Collaboration Revenue [Line Items]
Collaboration revenue	2,940	3,132	8,724	9,252
Teva [Member] \| Research Funding [Member] \| Collaborative Arrangement [Member]
Collaboration Revenue [Line Items]
Collaboration revenue	11	84	101	251
Genentech [Member] \| Recognition of Upfront Payment [Member] \| Collaborative Arrangement [Member]
Collaboration Revenue [Line Items]
Collaboration revenue	182	981	542	2,736
Genentech [Member] \| Research Funding [Member] \| Collaborative Arrangement [Member]
Collaboration Revenue [Line Items]
Collaboration revenue	910	994	2,730	3,249
Genentech [Member] \| Milestone Payment [Member] \| Collaborative Arrangement [Member]
Collaboration Revenue [Line Items]
Collaboration revenue	$ 250	$ 7,987	$ 250	$ 7,987

Commitments and Contingencies (Details) (USD $) In Thousands, unless otherwise specified	9 Months Ended
	Sep. 30, 2015	Aug. 31, 2015
Unrecorded Unconditional Purchase Obligation [Line Items]
Initial payment for service agreement	$ 1,700
Medpace Clinical Development Service Agreement [Member]
Unrecorded Unconditional Purchase Obligation [Line Items]
Service agreement, term	five year
Committed service obligation		7,000
Initial payment for service agreement		1,700
Additional payment due in remainder of 2015		$ 1,300

Related Parties (Details) (Medpace Clinical Development Service Agreement [Member], USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014	Dec. 31, 2014
Related Party Transaction [Line Items]
Clinical development service fees to related parties	$ 512	$ 0	$ 567	$ 0
Due to related parties	$ 512		$ 512		$ 0
Dr. August J. Troendle, Officer and Director [Member] \| Minimum [Member]
Related Party Transaction [Line Items]
Percentage of ownership	5.00%		5.00%

Stock Option Plan (Details) (USD $)	9 Months Ended
Stock Option Plan (Details) (USD $)	Sep. 30, 2015	Sep. 30, 2014
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Weighted Average Grant Date Fair Value, Granted	$ 11.50	$ 6.58

Long Term Prepaid Expenses (Details) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2015	Aug. 31, 2015 Medpace Clinical Development Service Agreement [Member]
Long Term Prepaid Expenses [Line Items]
Initial payment for service agreement	$ 1,700	$ 1,700