0001564590-21-026590 | 10-Q | XBRL Viewer | Xenon Pharmaceuticals INC

Document And Entity Information - shares	3 Months Ended
Document And Entity Information - shares	Mar. 31, 2021	May 07, 2021
Cover [Abstract]
Entity Registrant Name	XENON PHARMACEUTICALS INC.
Document Type	10-Q
Current Fiscal Year End Date	--12-31
Amendment Flag	false
Entity Common Stock, Shares Outstanding		40,967,221
Entity Central Index Key	0001582313
Entity Filer Category	Non-accelerated Filer
Document Period End Date	Mar. 31, 2021
Document Fiscal Year Focus	2021
Document Fiscal Period Focus	Q1
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Small Business	true
Entity Shell Company	false
Entity Emerging Growth Company	false
Entity File Number	001-36687
Entity Tax Identification Number	98-0661854
Entity Address, Address Line One	200-3650 Gilmore Way
Entity Address, City or Town	Burnaby
Entity Address, State or Province	BC
Entity Address, Country	CA
Entity Address, Postal Zip Code	V5G 4W8
City Area Code	604
Local Phone Number	484-3300
Title of 12(b) Security	Common Shares, without par value
Trading Symbol	XENE
Security Exchange Name	NASDAQ
Entity Incorporation, State or Country Code	Z4
Document Quarterly Report	true
Document Transition Report	false

Consolidated Balance Sheets (Unaudited) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Current assets:
Cash and cash equivalents	$ 87,985	$ 45,009
Marketable securities	186,718	131,988
Accounts receivable	5,060	1,822
Prepaid expenses and other current assets	3,497	2,964
Total current assets	283,260	181,783
Operating lease right-of-use asset, net (note 6)	3,206	3,326
Property, plant and equipment, net	3,691	3,554
Deferred tax assets (note 11)	514	523
Total assets	290,671	189,186
Current liabilities:
Accounts payable and accrued expenses (note 7)	7,580	10,874
Deferred revenue (note 10)	3,642	3,642
Operating lease liability (note 6)	270	265
Total current liabilities	11,492	14,781
Operating lease liability, long-term (note 6)	2,902	3,050
Total liabilities	14,394	17,831
Shareholders’ equity:
Preferred shares, without par value; unlimited shares authorized; issued and outstanding: 1,016,000 (December 31, 2020 - 1,016,000) (note 9)	7,732	7,732
Common shares, without par value; unlimited shares authorized; issued and outstanding: 40,962,715 (December 31, 2020 - 35,012,125) (note 9)	498,334	397,748
Additional paid-in capital	65,457	45,357
Accumulated deficit	(294,256)	(278,492)
Accumulated other comprehensive loss	(990)	(990)
Shareholders' equity	276,277	171,355
Total liabilities and shareholders’ equity	290,671	189,186
Commitments and contingencies (note 12)

Consolidated Balance Sheets (Unaudited) (Parenthetical) - $ / shares	3 Months Ended	12 Months Ended
	Mar. 31, 2021	Dec. 31, 2020
Statement Of Financial Position [Abstract]
Preferred shares, without par value
Preferred shares, shares authorized	Unlimited	Unlimited
Preferred shares, issued	1,016,000	1,016,000
Preferred shares, outstanding	1,016,000	1,016,000
Common shares, without par value
Common shares, shares authorized	Unlimited	Unlimited
Common shares, Issued	40,962,715	35,012,125
Common shares, Outstanding	40,962,715	35,012,125

Consolidated Statements of Operations and Comprehensive Loss (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Income Statement [Abstract]
Revenue (note 10)	$ 4,358	$ 7,078
Operating expenses:
Research and development	16,308	11,791
General and administrative	4,109	3,320
Total operating expenses	20,417	15,111
Loss from operations	(16,059)	(8,033)
Other income (expense):
Interest income	72	1,116
Interest expense		(330)
Foreign exchange gain (loss)	155	(238)
Loss before income taxes	(15,832)	(7,485)
Income tax recovery (note 11)	68	1
Net loss and comprehensive loss	(15,764)	(7,484)
Net loss attributable to preferred shareholders	(423)	(222)
Net loss attributable to common shareholders	$ (15,341)	$ (7,262)
Net loss per common share (note 4):
Basic and diluted	$ (0.42)	$ (0.22)
Weighted-average common shares outstanding (note 4):
Basic and diluted	36,824,619	33,189,733

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

Total

Convertible Preferred Shares [Member]

Common Shares [Member]

Additional Paid-in Capital [Member]

Accumulated Deficit [Member]

Accumulated Other Comprehensive Loss [Member]

^[1]

Balance at Dec. 31, 2019

$ 91,977

$ 7,732

$ 294,244

$ 40,646

$ (249,655)

$ (990)

Balance (in Shares) at Dec. 31, 2019

1,016,000

28,139,228

Net loss

(7,484)

Issuance of common shares, net of issuance costs (note 9a)

102,456

$ 102,456

Issuance of common shares, net of issuance costs (note 9a) (in shares)

6,759,187

Stock-based compensation expense

1,015

Issued pursuant to exercise of stock options

$ 14

$ 607

(593)

Issued pursuant to exercise of of stock options (in Shares)

98,326

^[2]

57,857

Balance at Mar. 31, 2020

$ 187,978

$ 7,732

$ 397,307

41,068

(257,139)

(990)

Balance (in Shares) at Mar. 31, 2020

1,016,000

34,956,272

Balance at Dec. 31, 2020

171,355

$ 7,732

$ 397,748

45,357

(278,492)

(990)

Balance (in Shares) at Dec. 31, 2020

1,016,000

35,012,125

Net loss

(15,764)

Issuance of common shares, net of issuance costs (note 9a)

$ 99,846

Issuance of common shares, net of issuance costs (note 9a) (in shares)

5,868,135

Issuance of common shares and pre-funded warrants, net of issuance costs (note 9a and note 9c)

118,615

Issuance of common shares and pre-funded warrants, net of issuance costs (note 9a and note 9c)

18,769

Stock-based compensation expense

1,965

Issued pursuant to exercise of stock options

$ 106

$ 740

(634)

Issued pursuant to exercise of of stock options (in Shares)

122,403

^[2]

82,455

Balance at Mar. 31, 2021

$ 276,277

$ 7,732

$ 498,334

$ 65,457

$ (294,256)

$ (990)

Balance (in Shares) at Mar. 31, 2021

1,016,000

40,962,715

[1]	The accumulated other comprehensive loss is entirely related to historical cumulative translation adjustments from the application of U.S. dollar reporting when the functional currency of the Company was the Canadian dollar.
[2]	During the three months ended March 31, 2021, 46,296 (2020 – 1,972) stock options were exercised for the same number of common shares in exchange for cash. In the same period, the Company issued 36,159 (2020 – 55,885) common shares for the cashless exercise of 76,107 (2020 – 96,354) stock options.

Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Operating activities:
Net loss	$ (15,764)	$ (7,484)
Items not involving cash:
Depreciation	196	104
Amortization of discount on term loan		137
Deferred income tax expense	9	52
Stock-based compensation	1,965	1,015
Unrealized foreign exchange (gain) loss	(204)	522
Unrealized (gain) loss on marketable securities	74	(281)
Changes in operating assets and liabilities:
Accounts receivable	(3,238)	(824)
Prepaid expenses and other current assets	(533)	113
Accounts payable and accrued expenses	(3,213)	(577)
Deferred revenue		(5,844)
Net cash used in operating activities	(20,708)	(13,067)
Investing activities:
Purchases of property, plant and equipment	(404)	(647)
Purchases of marketable securities	(100,655)	(107,482)
Proceeds from marketable securities	45,955	55,204
Net cash used in investing activities	(55,104)	(52,925)
Financing activities:
Proceeds from issuance of common shares and pre-funded warrants, net of issuance costs (note 9a)	118,615	102,456
Issuance of common shares pursuant to exercise of stock options	106	14
Net cash provided by financing activities	118,721	102,470
Effect of exchange rate changes on cash and cash equivalents	67	(725)
Increase in cash and cash equivalents	42,976	35,753
Cash and cash equivalents, beginning of period	45,009	24,755
Cash and cash equivalents, end of period	87,985	60,508
Supplemental disclosures:
Interest paid		206
Interest received	651	1,172
Cash paid for operating lease	202	159
Supplemental disclosures of non-cash transactions:
Fair value of stock options exercised on a cashless basis	$ 448	$ 583

Nature of the Business

3 Months Ended

Mar. 31, 2021

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 predecessor to the Business Corporations Act (British Columbia) and continued federally in 2000 under the Canada Business Corporations Act, is a clinical stage biopharmaceutical company focused on developing innovative therapeutics to improve the lives of patients with neurological disorders, with a focus on epilepsy.

The Company has incurred significant operating losses since inception. As of March 31, 2021, the Company had an accumulated deficit of $294,256 and a $15,764 net loss for the three months ended March 31, 2021. 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 and pre-funded warrants and debt financings.

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, equity and debt financings. The continuation of 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

3 Months Ended

Mar. 31, 2021

Accounting Policies [Abstract]

Basis of Presentation

2.	Basis of presentation:

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

The Company has one wholly-owned subsidiary as of March 31, 2021, Xenon Pharmaceuticals USA Inc., which was incorporated in Delaware on December 2, 2016.

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

The accompanying unaudited interim consolidated 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 consolidated financial statements do not include all of the information and footnotes required for complete consolidated financial statements and should be read in conjunction with the audited consolidated financial statements and notes for the year ended December 31, 2020 and included in the Company’s 2020 Annual Report on Form 10-K filed with the SEC and with the securities commissions in British Columbia, Alberta and Ontario on March 1, 2021.

These unaudited interim consolidated 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 months ended March 31, 2021 and 2020 are not necessarily indicative of results that can be expected for a full year. These unaudited interim consolidated financial statements follow the same significant accounting policies as those described in the notes to the audited consolidated financial statements of the Company included in the Company’s 2020 Annual Report on Form 10-K for the year ended December 31, 2020, with the exception of the policies described in note 3 below.

Changes in Significant Accounting Policies

3 Months Ended

Mar. 31, 2021

Accounting Changes And Error Corrections [Abstract]

Changes in Significant Accounting Policies

3.	Changes in significant accounting policies:

In December 2019, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) 2019-12, Income Taxes (Topic 740): Simplifying the Accounting for Income Taxes. These amendments simplify accounting for income taxes, change the accounting for certain income tax transactions and make certain improvements to the codification. The Company has adopted this standard as of January 1, 2021 on a prospective basis. The adoption of the standard had no impact on the Company’s consolidated balance sheets, consolidated statements of operations and comprehensive loss and consolidated statements of cash flows.

- Definition

The entire disclosure for change in accounting principle. Includes, but is not limited to, nature, reason, and method of adopting amendment to accounting standards or other change in accounting principle.

+ References

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+ Details

Net Income (Loss) Per Common Share

3 Months Ended

Mar. 31, 2021

Earnings Per Share [Abstract]

Net Income (Loss) Per Common Share

4.	Net income (loss) per common share:

Basic net income (loss) per common share is calculated using the two-class method required for participating securities which includes 1,016,000 Series 1 Preferred Shares as a separate class for the three months ended March 31, 2021 (2020 – 1,016,000). The convertible preferred shares entitle the holders to participate in dividends and in earnings and losses of the Company on an equivalent basis as common shares. Accordingly, undistributed earnings (losses) are allocated to common shares and participating preferred shares based on the weighted-average shares of each class outstanding during the period.

The weighted average number of common shares used in the basic and diluted net income (loss) per common share calculations for the three months ended March 31, 2021 include the pre-funded warrants issued in connection with the Company’s March 2021 underwritten public offering (note 9c) as the pre-funded warrants are exercisable at any time for nominal cash consideration.

The treasury stock method is used to compute the dilutive effect of the Company’s stock options and warrants. Under this method, the incremental number of common shares used in computing diluted net income (loss) per common share is the difference between the number of common shares assumed issued and purchased using assumed proceeds.

The if-converted method is used to compute the dilutive effect of the Company’s convertible preferred shares. Under the if-converted method, dividends on the preferred shares, if applicable, are added back to earnings attributable to common shareholders, and the preferred shares and paid-in kind dividends are assumed to have been converted at the share price applicable at the end of the period. The if-converted method is applied only if the effect is dilutive.

For the three months ended March 31, 2021 and 2020, all stock options, warrants and convertible preferred shares were anti-dilutive and were excluded from the diluted weighted average common shares outstanding for the period.

Fair Value of Financial Instruments

3 Months Ended

Mar. 31, 2021

Fair Value Disclosures [Abstract]

Fair Value of Financial Instruments

5.	Fair value of financial instruments:

Certain financial instruments and other items are measured at fair value.

To determine the fair value, the Company uses 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.

- 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

Leases

3 Months Ended

Mar. 31, 2021

Leases [Abstract]

Leases

Leases:

The Company has one operating lease for research laboratories and office space in Burnaby, British Columbia. In October 2020, the Company entered into a lease amendment for a 21–month committed term from October 1, 2020 to June 30, 2022. A renewal option for a portion of the facility for a 5-year term that is reasonably certain of exercise has been included in the determination of the right-of-use asset and lease liability.

The cost components of the operating lease were as follows for the three months ended March 31, 2021 and 2020:

	Three Months Ended March 31,
	2021			2020
Lease Cost
Operating lease expense	$	139		$	109
Variable lease expense⁽¹⁾		184			136
Lease Term and Discount Rate
Remaining lease term (years)	6.25			2
Discount rate		2.45	%		3.75	%

⁽¹⁾

^{Variable lease costs are payments that vary because of changes in facts or circumstances and include common area maintenance and property taxes related to the premises. Variable lease costs are excluded from the calculation of minimum lease payments.}

Future minimum lease payments as of March 31, 2021 were as follows:

Year ending December 31:
2021	$	618
2022		703
2023		576
2024		576
2025 and thereafter		1,441
Total future minimum lease payments	$	3,914
Less: imputed interest		(268	)
Less: future lease incentives reasonably certain of use		(474	)
Present value of lease liabilities	$	3,172

Accounts Payable and Accrued Expenses

3 Months Ended

Mar. 31, 2021

Payables And Accruals [Abstract]

Accounts Payable and Accrued Expenses

7.	Accounts payable and accrued expenses:

Accounts payable and accrued expenses consisted of the following:

	March 31,		December 31,
	2021		2020
Trade payables	$	2,132	$	3,041
Employee compensation, benefits, and related accruals		1,323		2,859
Consulting and contracted research		3,754		4,738
Professional fees		289		167
Other		82		69
Total	$	7,580	$	10,874

Term Loan

3 Months Ended

Mar. 31, 2021

Debt Disclosure [Abstract]

Term Loan

8.	Term loan:

In August 2018, the Company entered into an Amended and Restated Loan and Security Agreement (the “Amended and Restated Loan Agreement”) with Silicon Valley Bank (the “Bank”), pursuant to which the Bank agreed to extend a term loan to the Company with a principal amount of $15,500. The Term Loan accrued interest at a floating per annum rate of 0.5% above the prime rate. The Term Loan was interest-only until March 31, 2020, followed by 30 equal monthly installments of principal plus interest, originally maturing on September 1, 2022. In addition, the Company was required to pay a final payment fee of 6.5% of the Term Loan on the date on which the term loan was prepaid, paid or became due and payable in full.

In May 2020, the Company repaid the total outstanding term loan balance ahead of the maturity date. The repayment consisted of (i) the outstanding principal balance, (ii) a final payment fee of $1,008, which was partially accrued up to the date of repayment, and (iii) a prepayment fee of $225. At the time of repayment, all liabilities and obligations under the Amended and Restated Loan Agreement terminated automatically. The Company recorded a loss on repayment of the term loan of $988, which represents the difference between the carrying value of the term loan on the repayment date and the amount paid to extinguish the term loan. The repayment did not affect the Bank’s rights in connection with the warrant to the Bank to purchase 40,000 of our common shares at a price per common share of $9.79 which will remain outstanding until exercised or expired in August 2028.

Share Capital

3 Months Ended

Mar. 31, 2021

Stockholders Equity Note [Abstract]

Share Capital

9.	Share capital:

(a)

Financing:

In November 2019, the Company entered into an at-the-market equity offering sales agreement with Jefferies LLC (“Jefferies”) and Stifel, Nicolaus & Company, Incorporated (“Stifel”) to sell common shares of the Company having aggregate gross proceeds of up to $50,000 from time to time, through an “at-the-market” equity offering program under which Jefferies and Stifel would act as sales agents. As of December 31, 2019, the Company had sold 805,643 common shares under the sales agreement for proceeds of approximately $10,729, net of commissions paid and transaction expenses. In January 2020, the Company sold an additional 2,446,687 common shares for proceeds of approximately $37,796, net of commissions paid and transaction expenses.

In January 2020, the Company entered into an underwriting agreement with Jefferies, Stifel and Guggenheim Securities, LLC, relating to an underwritten public offering of 3,750,000 common shares sold by the Company at a public offering price of $16.00 per common share, and granted the underwriters an option for a period of 30 days to purchase up to an additional 562,500 common shares. The public offering was completed in January 2020, and the Company received net proceeds of $56,265, net of underwriting discounts, commissions and offering expenses. The underwriters exercised their option in full in February 2020 and the Company received additional proceeds of $8,395, net of underwriting discounts, commissions and offering expenses.

In August 2020, the Company entered into an at-the-market equity offering sales agreement with Jefferies and Stifel to sell common shares of the Company having aggregate gross proceeds of up to $100,000, from time to time, through an “at-the-market” equity offering program under which Jefferies and Stifel would act as sales agents. As of March 31, 2021, 733,000 common shares have been sold under the sales agreement for proceeds of approximately $10,693, net of commissions paid and transaction expenses.

In March 2021, the Company entered into an underwriting agreement with Jefferies and Stifel, relating to an underwritten public offering of 5,135,135 common shares, including 810,810 common shares sold upon the full exercise of the underwriters’ over-allotment option, at a public offering price of $18.50 per common share and pre-funded warrants to purchase 1,081,081 common shares (the “Pre-Funded Warrants”) at $18.4999 per Pre-Funded Warrant (note 9c). The public offering was completed in March 2021, and the Company received proceeds of $107,922, net of underwriting discounts, commissions and offering expenses.

(b)

Exchange agreement with certain funds affiliated with BVF Partners L.P. (collectively, “BVF”):

In March 2018, the Company and BVF entered into an exchange agreement pursuant to which the Company issued to BVF 2,868,000 Series 1 Preferred Shares in exchange for 2,868,000 common shares which were subsequently cancelled by the Company.

The Company filed articles of amendment creating an unlimited number of Series 1 Preferred Shares. The Series 1 Preferred Shares are convertible into common shares on a one-for-one basis subject to the holder, together with its affiliates, beneficially owning no more than 9.99% of the total number of common shares issued and outstanding immediately after giving effect to such conversion (the “Beneficial Ownership Limitation”). The holder may reset the Beneficial Ownership Limitation to a higher or lower number, not to exceed 19.99% of the total number of common shares issued and outstanding immediately after giving effect to such conversion, upon providing written notice to the Company which will be effective 61 days after delivery of such notice. Each Series 1 Preferred Share is also convertible into one common share at any time at the Company’s option without payment of additional consideration, provided that prior to any such conversion, the holder, together with its affiliates, beneficially owns less than 5.00% of the total number of common shares issued and outstanding and such conversion will not result in the holder, together with its affiliates, beneficially holding more than 5.00% of the total number of common shares issued and outstanding immediately after giving effect to such conversion. In the event of a change of control, holders of Series 1 Preferred Shares shall be issued one common share for each outstanding Series 1 Preferred Share held immediately prior to the change of control (without regard to the Beneficial Ownership Limitation), and following such conversion, will be entitled to receive the same kind and amount of securities, cash or property that a holder of common shares is entitled to receive in connection with such change of control.

The Series 1 Preferred Shares rank equally to the common shares in the event of liquidation, dissolution or winding up or other distribution of the assets of the Company among its shareholders and the holders of the Series 1 Preferred Shares are entitled to vote together with the common shares on an as-converted basis and as a single class, subject in the case of each holder of the Series 1 Preferred Shares to the Beneficial Ownership Limitation. Any Series 1 Preferred Shares that are ineligible to be converted into common shares due to the Beneficial Ownership Limitation, measured as of a given record date that applies for a shareholder meeting or ability to act by written consent, shall be deemed to be non-voting securities of the Company. Holders of Series 1 Preferred Shares are entitled to receive dividends (without regard to the Beneficial Ownership Limitation) on the same basis as the holders of common shares. The Company may not redeem the Series 1 Preferred Shares.

The Company recorded the issuance of Series 1 Preferred Shares and corresponding cancellation of common shares at $7.61 per share, the estimated weighted average cost at which BVF acquired the common shares. The Series 1 Preferred Shares are recorded wholly as equity under ASC 480, with no bifurcation of conversion feature from the host contract, given that the Series 1 Preferred Shares cannot be cash settled and have no redemption features.

During the year ended December 31, 2018, BVF converted 1,852,000 Series 1 Preferred Shares in exchange for an equal number of common shares of the Company.

BVF was a related party of the Company prior to the closing of the exchange agreement, and continues to be a related party as of March 31, 2021.

(c)

Pre-Funded Warrants:

In connection with an underwritten public offering completed in March 2021, the Company issued 1,081,081 Pre-Funded Warrants at a price of $18.4999 per Pre-Funded Warrant which grants the holder the right to purchase up to 1,081,081 common shares at an exercise price of $0.0001 per share. The Pre-Funded Warrants are exercisable at the holder’s discretion from the date of issuance until the date the Pre-Funded Warrant is exercised in full. The Company may not affect the exercise of any Pre-Funded Warrant, and a holder will not be entitled to exercise any portion of any Pre-Funded Warrant that, upon giving effect to such exercise, would cause: (i) the aggregate number of common shares beneficially owned by such holder, together with its affiliates, to exceed 4.99% of the total number of common shares outstanding immediately after giving effect to the exercise; or (ii) the combined voting power of the Company’s securities beneficially owned by such holder, together with its affiliates, to exceed 4.99% of the combined voting power of all of the Company’s securities immediately outstanding after giving effect to the exercise, which percentage may be changed at the holder’s election to a higher or lower percentage not in excess of 19.99% upon at least 61 days’ notice to the Company.

Since the Pre-Funded Warrants meet the condition for equity classification, proceeds from issuance of the Pre-Funded Warrants of $18,769, net of underwriting discounts, commissions and offering expenses, are recorded in additional paid-in capital. Upon exercise of the Pre-Funded Warrants, the historical costs recorded in additional paid-in capital along with the exercise price collected from holder will be recorded in common shares. As of March 31, 2021, no Pre-Funded Warrants have been exercised. Pre-funded warrants to purchase 1,081,081 common shares are not included in the number of issued and outstanding common shares as of March 31, 2021.

(d)

Stock-based compensation:

The following table presents stock option activity for the period:

	Three Months Ended March 31,
	2021			2020
Outstanding, beginning of period		4,758,997			3,534,236
Granted		1,111,950			1,118,350
Exercised⁽¹⁾		(122,403	)		(98,326	)
Forfeited, cancelled or expired		(5,936	)		(26,268	)
Outstanding, end of period		5,742,608			4,527,992
Exercisable, end of period		2,769,438			1,992,705

(1)

During the three months ended March 31, 2021, 46,296 (2020 – 1,972) stock options were exercised for the same number of common shares in exchange for cash. In the same period, the Company issued 36,159 (2020 – 55,885) common shares for the cashless exercise of 76,107 (2020 – 96,354) stock options.

The fair value of each stock option granted is estimated using the Black-Scholes option-pricing model with the following weighted-average assumptions:

	Three Months Ended March 31,
	2021			2020
Average risk-free interest rate		1.15	%		0.80	%
Expected volatility		68	%		68	%
Average expected term (in years)		6.53			6.73
Expected dividend yield		0	%		0	%
Weighted average fair value of stock options granted	$	12.86		$	7.41

Revenue

3 Months Ended

Mar. 31, 2021

Revenue From Contract With Customer [Abstract]

Revenue

10.

Revenue:

Revenue was as follows for the three months ended March 31, 2021 and 2020:

	Three Months Ended March 31,
	2021		2020
Neurocrine Biosciences:
Recognition of the transaction price	$	—	$	5,844
Research and development services		1,358		1,234
Flexion:
Milestone payments		3,000		—
Total collaboration revenue	$	4,358	$	7,078

(a)

Neurocrine Biosciences license and collaboration agreement:

In December 2019, the Company entered into a License and Collaboration Agreement with Neurocrine Biosciences Inc. (“Neurocrine Biosciences”). Pursuant to this agreement, the Company granted an exclusive license to XEN901, now known as NBI-921352, and an exclusive license to pre-clinical compounds for development, XEN393, XPC’535 and XPC’391 (collectively, the “DTCs”). The agreement also includes a two-year research collaboration to discover, identify and develop additional novel Nav1.6 and Nav1.2/1.6 inhibitors (“Research Compounds”), with an option to extend for an additional year. The Company and Neurocrine Biosciences are collaborating on the conduct of two collaboration programs: (a) a joint research collaboration to discover, identify and preclinically develop Research Compounds (the “Research Program”) and (b) a collaborative development program for XEN901 and two DTCs selected by the joint steering committee (the “Initial Development Program”).

At execution of the agreement, Neurocrine Biosciences paid the Company an upfront cash payment of $30,000 and a $20,000 equity investment in the Company. The equity investment was measured at fair value of $16,667 on the date of issuance and the resulting premium $3,333, together with the upfront cash payment totaling $33,333, was the transaction price of the arrangement for allocation to the performance obligations. The agreement includes the following performance obligations: (i) an exclusive license to XEN901 with associated technology and know-how transfer, (ii) an exclusive license to the DTCs with associated know-how transfer, (iii) a license to Research Compounds and research services under the Research Program, (iv) development services under the Initial Development Program for XEN901, and (v) development services under the Initial Development Program for the DTCs. The total transaction price of $33,333 was allocated to performance obligation (v) based on its estimated standalone selling price determined based on internal development plans and budget, with the balance allocated to performance obligations (i) and (ii) by the residual approach. The Company allocated the transaction price as follows: $28,807 to performance obligations (i) and (ii), completed as of December 2020, and $5,118, which includes $592 of variable consideration, to performance obligation (v), which is expected to be completed by Q1 2022.

The arrangement consideration related to the services under performance obligations (iii) and (iv) to be performed on behalf of Neurocrine Biosciences were excluded from the initial transaction price allocation because the consideration and performance are contingent upon Neurocrine Biosciences requesting performance of the services and these services are priced at an estimated fair value. None of the at-risk substantive performance milestones, including development, regulatory and sales-based milestones, were included in the transaction price, as all milestone amounts are outside the control of the Company and contingent upon Neurocrine Biosciences’s efforts and success in future clinical trials. The Company will re-evaluate the transaction price in each reporting period and as uncertain events are resolved or other changes in circumstances occur.

During the three months periods ended March 31, 2021 and 2020, the Company recognized $1,358 and $7,078 of revenue, respectively, which comprised of $nil and $5,761, respectively, associated with (i) the exclusive license to XEN901 and (ii) the exclusive license to the DTCs; $1,358 and $1,234, respectively, for the research and development services under (iii) the Research Program and (iv) the Initial Development Program for XEN901; and $nil and $83, respectively, for (v) development services under the Initial Development Program for the DTCs. As of March 31, 2021, there is $1,358 of accounts receivable and $3,642 of deferred revenue related to the Neurocrine Collaboration Agreement, which is classified as current on the balance sheet based on the period the services are expected to be delivered.

The Company has an option to co-fund 50% of the development costs of XEN901 or another product candidate in the U.S., exercisable upon achievement of certain milestones, in exchange for increased U.S. royalties. The Company has not exercised this option as of March 31, 2021.

(b)

Flexion definitive agreement:

In September 2019, the Company entered into an agreement with Flexion Therapeutics Inc. (“Flexion”) pursuant to which Flexion acquired all rights with respect to XEN402, and a related compound (collectively “XEN402”), including certain regulatory documentation, intellectual property rights, reports, data and all quantities of XEN402, now known as FX301, owned or controlled by the Company.

During the three months ended March 31, 2021, the U.S. Food and Drug Administration cleared the first investigational new drug application for FX301 and Flexion initiated a Phase 1b clinical trial, resulting in milestone payments of $1,000 and $2,000 due to the Company, respectively. Pursuant to terms of the agreement, the Company will also be eligible for a development milestone payment of $5,000 upon initiation of a Phase 2 proof-of-concept clinical trial. Following successful proof-of-concept, the Company may be entitled to future clinical development and global regulatory approval milestone payments of up to $40,750, commercial milestone payments of up to $75,000, as well as future royalties ranging from mid-single to low-double digit percentages. These additional amounts will be recognized as determinable.

- Definition

The entire disclosure of revenue from contract with customer to transfer good or service and to transfer nonfinancial asset. Includes, but is not limited to, disaggregation of revenue, credit loss recognized from contract with customer, judgment and change in judgment related to contract with customer, and asset recognized from cost incurred to obtain or fulfill contract with customer. Excludes insurance and lease contracts.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-URI http://asc.fasb.org/topic&trid=49130388

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
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-Section 50
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-URI http://asc.fasb.org/extlink&oid=121604090&loc=SL49130551-203045

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
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-Name Accounting Standards Codification
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Reference 4: http://www.xbrl.org/2003/role/disclosureRef
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Reference 6: http://www.xbrl.org/2003/role/disclosureRef
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+ Details

Income Taxes

3 Months Ended

Mar. 31, 2021

Income Tax Disclosure [Abstract]

Income Taxes

11.	Income taxes:

Income tax recovery for the three months ended March 31, 2021 and 2020 arose from the operations of Xenon Pharmaceuticals USA Inc., the Company’s wholly-owned subsidiary in the United States. Deferred income tax assets recorded on the consolidated balance sheets as of March 31, 2021 and December 31, 2020 resulted from the temporary differences between the amounts of assets and liabilities recognized for financial statement and income tax purposes related to the operations of Xenon Pharmaceuticals USA Inc. 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.

- Definition

The entire disclosure for income taxes. Disclosures may include net deferred tax liability or asset recognized in an enterprise's statement of financial position, net change during the year in the total valuation allowance, approximate tax effect of each type of temporary difference and carryforward that gives rise to a significant portion of deferred tax liabilities and deferred tax assets, utilization of a tax carryback, and tax uncertainties information.

+ References + Details

Commitments and Contingencies

3 Months Ended

Mar. 31, 2021

Commitments And Contingencies Disclosure [Abstract]

Commitments and Contingencies

12.	Commitments and contingencies:

(a)

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 which the Company has committed to using Medpace non-exclusively for clinical development services over the five-year term of the agreement which ended in August 2020. The Company has committed to $7,000 of services over the term of the agreement of which $3,461 of services have been received and $3,539 remains committed as of March 31, 2021. As the Company did not meet the commitment to retain Medpace for $7,000 of services prior to August 2020, the Company is required to provide Medpace the exclusive right to perform all subsequent outsourced clinical development work until such $7,000 commitment has been satisfied, subject to the availability of appropriate Medpace resources and reasonable service rates. If the Company decides not to retain Medpace for the provision of clinical development services, the Company may satisfy its obligations under the priority access agreement by paying Medpace an amount equal to half of the unsatisfied portion. The Company intends to continue to utilize Medpace for clinical development work where suitable in order to fulfill the remaining commitment; therefore, no liability has been recognized as of March 31, 2021 with respect to the unsatisfied portion under the priority access agreement.

(b)

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 will be required to pay a low single-digit percentage royalty on net sales of any products developed and commercialized under the agreement.

(c)

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. In August 2020, the Company and 1stOrder amended the asset purchase agreement to amend certain definitions in the agreement and to modify the payment schedule for certain milestones. Future potential payments to 1st Order related to the XEN1101 program include up to $1,200 in clinical development milestones, up to $6,000 in regulatory milestones, and $500 in other milestones. To date, the Company has paid $300 based on progress against these milestones. There are no royalty obligations to 1st Order.

(d)

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. 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. No amounts have been accrued to date based on the progress against these milestones.

(e)

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.

Leases (Tables)

3 Months Ended

Mar. 31, 2021

Leases [Abstract]

Schedule of Cost Components of Operating Lease

The cost components of the operating lease were as follows for the three months ended March 31, 2021 and 2020:

	Three Months Ended March 31,
	2021			2020
Lease Cost
Operating lease expense	$	139		$	109
Variable lease expense⁽¹⁾		184			136
Lease Term and Discount Rate
Remaining lease term (years)	6.25			2
Discount rate		2.45	%		3.75	%

⁽¹⁾

Future Minimum Lease Payments

Future minimum lease payments as of March 31, 2021 were as follows:

Year ending December 31:
2021	$	618
2022		703
2023		576
2024		576
2025 and thereafter		1,441
Total future minimum lease payments	$	3,914
Less: imputed interest		(268	)
Less: future lease incentives reasonably certain of use		(474	)
Present value of lease liabilities	$	3,172

Accounts Payable and Accrued Expenses (Tables)

3 Months Ended

Mar. 31, 2021

Payables And Accruals [Abstract]

Accounts Payable and Accrued Expenses

Accounts payable and accrued expenses consisted of the following:

	March 31,		December 31,
	2021		2020
Trade payables	$	2,132	$	3,041
Employee compensation, benefits, and related accruals		1,323		2,859
Consulting and contracted research		3,754		4,738
Professional fees		289		167
Other		82		69
Total	$	7,580	$	10,874

Share Capital (Tables)

3 Months Ended

Mar. 31, 2021

Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]

Stock Option Activity

The following table presents stock option activity for the period:

	Three Months Ended March 31,
	2021			2020
Outstanding, beginning of period		4,758,997			3,534,236
Granted		1,111,950			1,118,350
Exercised⁽¹⁾		(122,403	)		(98,326	)
Forfeited, cancelled or expired		(5,936	)		(26,268	)
Outstanding, end of period		5,742,608			4,527,992
Exercisable, end of period		2,769,438			1,992,705

(1)

Fair Value Assumptions for Stock Options

The fair value of each stock option granted is estimated using the Black-Scholes option-pricing model with the following weighted-average assumptions:

	Three Months Ended March 31,
	2021			2020
Average risk-free interest rate		1.15	%		0.80	%
Expected volatility		68	%		68	%
Average expected term (in years)		6.53			6.73
Expected dividend yield		0	%		0	%
Weighted average fair value of stock options granted	$	12.86		$	7.41

Revenue (Tables)

3 Months Ended

Mar. 31, 2021

Revenue From Contract With Customer [Abstract]

Schedule Of Collaboration Revenue

Revenue was as follows for the three months ended March 31, 2021 and 2020:

	Three Months Ended March 31,
	2021		2020
Neurocrine Biosciences:
Recognition of the transaction price	$	—	$	5,844
Research and development services		1,358		1,234
Flexion:
Milestone payments		3,000		—
Total collaboration revenue	$	4,358	$	7,078

Nature of the Business (Details) - USD ($) $ in Thousands	3 Months Ended
Nature of the Business (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Mar. 31, 2020	Dec. 31, 2020
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Accumulated deficit	$ 294,256		$ 278,492
Net loss	$ 15,764	$ 7,484

- Definition

The portion of profit or loss for the period, net of income taxes, which is attributable to the parent.

+ References

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+ Details

Basis of Presentation (Details)	3 Months Ended
Basis of Presentation (Details)	Mar. 31, 2021
Xenon Pharmaceuticals USA Inc. [Member]
Basis Of Presentation [Line Items]
Date of incorporation	Dec. 02, 2016

Net Income (Loss) Per Common (Details) - shares	Mar. 31, 2021	Dec. 31, 2020	Mar. 31, 2020
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Preferred shares, issued	1,016,000	1,016,000
Series1 Preferred Shares
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Preferred shares, issued	1,016,000		1,016,000

Leases (Details) - Burnaby, British Columbia [Member]	3 Months Ended
Leases (Details) - Burnaby, British Columbia [Member]	Mar. 31, 2021 Lease
Lessee Lease Description [Line Items]
Number of operating leases	1
Operating lease term	21 months
Operating lease expiration date	Jun. 30, 2022
Operating lease extension term	5 years
Operating lease, description	The Company has one operating lease for research laboratories and office space in Burnaby, British Columbia. In October 2020, the Company entered into a lease amendment for a 21–month committed term from October 1, 2020 to June 30, 2022. A renewal option for a portion of the facility for a 5-year term that is reasonably certain of exercise has been included in the determination of the right-of-use asset and lease liability.

Leases - Schedule of Cost Components of Operating Lease (Details) - USD ($)
$ in Thousands

3 Months Ended

Mar. 31, 2021

Mar. 31, 2020

Leases [Abstract]

Operating lease expense

$ 139

$ 109

Variable lease expense

^[1]

$ 184

$ 136

Remaining lease term (years)

6 years 3 months

2 years

Discount rate

2.45%

3.75%

[1]	Variable lease costs are payments that vary because of changes in facts or circumstances and include common area maintenance and property taxes related to the premises. Variable lease costs are excluded from the calculation of minimum lease payments.

Leases - Future Minimum Lease Payments (Details) $ in Thousands	Mar. 31, 2021 USD ($)
Commitments And Contingencies Disclosure [Abstract]
2021	$ 618
2022	703
2023	576
2024	576
2025 and thereafter	1,441
Total future minimum lease payments	3,914
Less: imputed interest	(268)
Less: future lease incentives reasonably certain of use	(474)
Present value of lease liabilities	$ 3,172

Accounts Payable and Accrued Expenses - Accounts Payable and Accrued Expenses (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Payables And Accruals [Abstract]
Trade payables	$ 2,132	$ 3,041
Employee compensation, benefits, and related accruals	1,323	2,859
Consulting and contracted research	3,754	4,738
Professional fees	289	167
Other	82	69
Total	$ 7,580	$ 10,874

Term Loan (Details) - Term Loan [Member] - USD ($) $ / shares in Units, $ in Thousands	1 Months Ended		3 Months Ended
	May 31, 2020	Aug. 31, 2018	Jun. 30, 2020	Mar. 31, 2021
Debt Instrument [Line Items]
Debt instrument, commencing period		2018-08
Debt instrument, interest only payment end date		Mar. 31, 2020
Debt instrument principal repayment period		30 months
Debt instrument, maturity date		Sep. 01, 2022
Debt instrument, final payment fee percentage		6.50%
Debt instrument, final payment fee	$ 1,008
Debt instrument prepayment fee	$ 225
Warrants outstanding to purchase common stock				40,000
Warrants exercise price per common share				$ 9.79
Loss on repayment of term loan			$ 988
Prime Rate [Member]
Debt Instrument [Line Items]
Debt instrument, floating interest rate		0.50%
Silicon Valley Bank [Member] \| Loan Agreement [Member]
Debt Instrument [Line Items]
Aggregate principal amount of debt instrument		$ 15,500

Share Capital (Details) - USD ($) $ / shares in Units, $ in Thousands	1 Months Ended						3 Months Ended		12 Months Ended
	Mar. 31, 2021	Aug. 31, 2020	Feb. 29, 2020	Jan. 31, 2020	Nov. 30, 2019	Mar. 31, 2018	Mar. 31, 2021	Mar. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Share Capital [Line Items]
Amount offered for issuance of common stock								$ 102,456
Series1 Preferred Shares
Share Capital [Line Items]
Conversion of shares										1,852,000
Common Shares [Member]
Share Capital [Line Items]
Conversion of shares										1,852,000
BVF Partners L.P [Member] \| Exchange Agreement [Member]
Share Capital [Line Items]
Estimated weighted average cancellation price per share of common stock						$ 7.61
BVF Partners L.P [Member] \| Exchange Agreement [Member] \| Series1 Preferred Shares
Share Capital [Line Items]
Shares issued						2,868,000
Preferred shares convertible into common shares						one-for-one
Maximum beneficial ownership limitation percentage for conversion of common stock issued and outstanding						9.99%
Maximum beneficial ownership limitation upon notice, percentage for conversion of common stock issued and outstanding						19.99%
Maximum beneficial percentage hold for conversion of number Of common stock issued and outstanding						5.00%
Minimum beneficial percentage hold for conversion of number Of common stock issued and outstanding.						5.00%
BVF Partners L.P [Member] \| Exchange Agreement [Member] \| Common Shares [Member]
Share Capital [Line Items]
Shares cancelled						2,868,000
Common Shares [Member]
Share Capital [Line Items]
Shares issued							5,868,135	6,759,187
Amount offered for issuance of common stock							$ 99,846	$ 102,456
Pre Funded Warrants
Share Capital [Line Items]
Warrants outstanding to purchase common stock	1,081,081						1,081,081
Warrants exercise price per common share	$ 18.4999						$ 18.4999
Warrants exercise price per common share	$ 0.0001						0.0001
Sale proceeds from issuance of pre funded warrants	$ 18,769
Number of warrants exercised	0
Warrants exercise description	The Company may not affect the exercise of any Pre-Funded Warrant, and a holder will not be entitled to exercise any portion of any Pre-Funded Warrant that, upon giving effect to such exercise, would cause: (i) the aggregate number of common shares beneficially owned by such holder, together with its affiliates, to exceed 4.99% of the total number of common shares outstanding immediately after giving effect to the exercise; or (ii) the combined voting power of the Company’s securities beneficially owned by such holder, together with its affiliates, to exceed 4.99% of the combined voting power of all of the Company’s securities immediately outstanding after giving effect to the exercise, which percentage may be changed at the holder’s election to a higher or lower percentage not in excess of 19.99% upon at least 61 days’ notice to the Company.
Jefferies and Stifel [Member]
Share Capital [Line Items]
Shares issued	5,135,135
Shares price	$ 18.50						$ 18.50
Sale proceeds of common shares							10,693,000
Jefferies and Stifel [Member] \| Underwritten Public Offering [Member]
Share Capital [Line Items]
Amount offered for issuance of common stock	$ 107,922
Warrants outstanding to purchase common stock	1,081,081						1,081,081
Warrants exercise price per common share	$ 18.4999						$ 18.4999
Jefferies and Stifel [Member] \| At-The-Market Equity Offering [Member]
Share Capital [Line Items]
Amount offered for issuance of common stock				$ 37,796					$ 10,729
Jefferies and Stifel [Member] \| At-The-Market Equity Offering [Member] \| Maximum [Member]
Share Capital [Line Items]
Amount offered for issuance of common stock					$ 50,000
Amount offered for issuance of common stock		$ 100,000
Jefferies and Stifel [Member] \| At-The-Market Equity Offering [Member] \| Common Shares [Member]
Share Capital [Line Items]
Shares issued				2,446,687			733,000		805,643
Jefferies and Stifel [Member] \| Over Allotment [Member]
Share Capital [Line Items]
Shares issued	810,810
Jefferies, Stifel and Guggenheim Securities, LLC [Member] \| Underwritten Public Offering [Member]
Share Capital [Line Items]
Amount offered for issuance of common stock			$ 8,395	$ 56,265
Jefferies, Stifel and Guggenheim Securities, LLC [Member] \| Underwritten Public Offering [Member] \| Common Shares [Member]
Share Capital [Line Items]
Shares issued			562,500	3,750,000
Shares price				$ 16.00

Share Capital - Stock Option Activity (Details) - shares

3 Months Ended

Mar. 31, 2021

Mar. 31, 2020

Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]

Number of Options Outstanding, Beginning balance

4,758,997

3,534,236

Number of Options, Granted

1,111,950

1,118,350

Number of Options, Exercised

^[1]

(122,403)

(98,326)

Number of Options, Forfeited, cancelled or expired

(5,936)

(26,268)

Number of Options Outstanding, Ending balance

5,742,608

4,527,992

Number of Options Exercisable, End of period

2,769,438

1,992,705

[1]	During the three months ended March 31, 2021, 46,296 (2020 – 1,972) stock options were exercised for the same number of common shares in exchange for cash. In the same period, the Company issued 36,159 (2020 – 55,885) common shares for the cashless exercise of 76,107 (2020 – 96,354) stock options.

Share Capital - Stock Option Activity (Parenthetical) (Details) - shares	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Stock Options exercised for Number of Common Shares for cash	46,296	1,972
Common stock issued for cashless exercise	36,159	55,885
Cashless exercise of stock options	76,107	96,354

Share Capital - Fair Value Assumptions for Stock Options (Details) - $ / shares	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Fair Value Assumptions For Stock Options [Abstract]
Average risk-free interest rate	1.15%	0.80%
Expected volatility	68.00%	68.00%
Average expected term (in years)	6 years 6 months 10 days	6 years 8 months 23 days
Expected dividend yield	0.00%	0.00%
Weighted average fair value of stock options granted	$ 12.86	$ 7.41

Revenue - Schedule of Collaboration Revenue (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Disaggregation Of Revenue [Line Items]
Revenue	$ 4,358	$ 7,078
Collaboration Revenue [Member]
Disaggregation Of Revenue [Line Items]
Revenue	4,358	7,078
Neurocrine Biosciences [Member] \| Collaboration Revenue [Member]
Disaggregation Of Revenue [Line Items]
Recognition of the transaction price		5,844
Research and development services	1,358	$ 1,234
Flexion [Member] \| Collaboration Revenue [Member]
Disaggregation Of Revenue [Line Items]
Milestone payments	$ 3,000

- Definition

Amount, including tax collected from customer, of revenue from satisfaction of performance obligation by transferring promised good or service to customer. Tax collected from customer is tax assessed by governmental authority that is both imposed on and concurrent with specific revenue-producing transaction, including, but not limited to, sales, use, value-added and excise.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
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Reference 2: http://www.xbrl.org/2003/role/disclosureRef
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Reference 3: http://www.xbrl.org/2003/role/disclosureRef
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+ Details

Revenue - Additional Information (Details) - USD ($) $ in Thousands	3 Months Ended		12 Months Ended
	Mar. 31, 2021	Mar. 31, 2020	Dec. 31, 2020	Dec. 31, 2019
Disaggregation Of Revenue [Line Items]
Revenue	$ 4,358	$ 7,078
Accounts receivable	5,060		$ 1,822
Collaboration Revenue [Member]
Disaggregation Of Revenue [Line Items]
Revenue	4,358	7,078
Neurocrine Biosciences [Member]
Disaggregation Of Revenue [Line Items]
Accounts receivable	1,358
Deferred revenue	3,642
Neurocrine and Flexion [Member] \| Collaboration Revenue [Member]
Disaggregation Of Revenue [Line Items]
Revenue	1,358	7,078
Exclusive License to XEN901 and Exclusive License to DTCs [Member] \| Neurocrine Biosciences [Member] \| Collaboration Revenue [Member]
Disaggregation Of Revenue [Line Items]
Revenue	0	5,761
Development Services Under the Initial Development Program For DTCs [Member] \| Neurocrine Biosciences [Member] \| Collaboration Revenue [Member]
Disaggregation Of Revenue [Line Items]
Revenue	0	83
Research And Development Funding \| Neurocrine Biosciences [Member] \| Collaboration Revenue [Member]
Disaggregation Of Revenue [Line Items]
Revenue	$ 1,358	$ 1,234
License and Collaboration Agreement [Member] \| Neurocrine Biosciences [Member]
Disaggregation Of Revenue [Line Items]
Upfront payment received in cash				$ 30,000
Upfront payment received in equity investment				20,000
Equity investment measured at fair value				16,667
Collaborate agreement premium related to equity investment				3,333
Transaction price allocated to performance obligations				33,333
Percentage of option to co-fund development costs upon achievement of certain milestones	50.00%
License and Collaboration Agreement [Member] \| Exclusive License to XEN901 and Exclusive License to DTCs [Member] \| Neurocrine Biosciences [Member]
Disaggregation Of Revenue [Line Items]
Transaction price allocated to performance obligations				$ 28,807
License and Collaboration Agreement [Member] \| Development Services Under the Initial Development Program For DTCs [Member] \| Neurocrine Biosciences [Member]
Disaggregation Of Revenue [Line Items]
Transaction price allocated to performance obligations			$ 5,118
Variable consideration allocated to performance obligation	$ 592
Asset Purchase Agreement [Member] \| Flexion [Member] \| XEN402 [Member]
Disaggregation Of Revenue [Line Items]
Food and drug administration milestone payment accepted	1,000
Milestone payment due on initiation of Phase 1b clinical trial	2,000
Asset Purchase Agreement [Member] \| Eligible to Receive Development Milestone Payment [Member] \| Flexion [Member] \| XEN402 [Member] \| Maximum [Member]
Disaggregation Of Revenue [Line Items]
Potential milestone payments receivable	5,000
Asset Purchase Agreement [Member] \| Future Clinical Development And Global Regulatory Approval Milestone Payments [Member] \| Flexion [Member] \| XEN402 [Member] \| Maximum [Member]
Disaggregation Of Revenue [Line Items]
Potential milestone payments receivable	40,750
Asset Purchase Agreement [Member] \| Commercial Milestone Payments [Member] \| Flexion [Member] \| XEN402 [Member] \| Maximum [Member]
Disaggregation Of Revenue [Line Items]
Potential milestone payments receivable	$ 75,000

Commitments and Contingencies (Details) - USD ($)	1 Months Ended				3 Months Ended
Commitments and Contingencies (Details) - USD ($)	Aug. 31, 2020	Jul. 31, 2017	Mar. 31, 2017	Aug. 31, 2015	Mar. 31, 2021
License, Manufacture and Supply Agreement [Member]
Commitments and Contingencies [Line Items]
Royalty obligation description			Under the terms of the agreement, the Company will be required to pay a low single-digit percentage royalty on net sales of any products developed and commercialized under the agreement.
Asset Purchase Agreement [Member] \| 1st Order Pharmaceuticals, Inc. [Member]
Commitments and Contingencies [Line Items]
Milestone payment paid					$ 300,000
Royalty obligation	$ 0
Asset Purchase Agreement [Member] \| 1st Order Pharmaceuticals, Inc. [Member] \| Clinical Development Milestones [Member]
Commitments and Contingencies [Line Items]
Future potential payments	1,200,000
Asset Purchase Agreement [Member] \| 1st Order Pharmaceuticals, Inc. [Member] \| Regulatory Milestone [Member] \| Maximum [Member]
Commitments and Contingencies [Line Items]
Future potential payments	6,000,000
Asset Purchase Agreement [Member] \| 1st Order Pharmaceuticals, Inc. [Member] \| Other Milestones [Member]
Commitments and Contingencies [Line Items]
Future potential payments	$ 500,000
License Agreement [Member]
Commitments and Contingencies [Line Items]
Royalty obligation description		low-to-mid single-digit percentage royalty on net sales of any products developed and commercialized under the agreement
License Agreement [Member] \| Clinical Development Milestones [Member]
Commitments and Contingencies [Line Items]
Future potential payments		$ 2,000,000
License Agreement [Member] \| Regulatory Milestone [Member] \| Maximum [Member]
Commitments and Contingencies [Line Items]
Future potential payments		$ 7,000,000
Priority Access Agreement with Medpace Inc. [Member]
Commitments and Contingencies [Line Items]
Service agreement, term				5 years
Committed service obligation				$ 7,000,000	3,539,000
Contractual obligation paid					$ 3,461,000