As filed with the Securities and Exchange Commission on December 7, 2015June 3, 2020

Registration No. 333-            

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM S-3

REGISTRATION STATEMENT

Under

THE SECURITIES ACT OFThe Securities Act Of 1933

XENON PHARMACEUTICALS INC.

(Exact name of Registrant as specified in its charter)

200 – 3650 Gilmore Way

Burnaby, British Columbia V5G 4W8  Canada

(604) 484-3300

(Address, including zip code, and telephone number, including area code, of Registrant’s principal executive offices)

Simon N. Pimstone

President and Chief Executive Officer

Xenon Pharmaceuticals Inc.

200 – 3650 Gilmore Way

Burnaby, British Columbia V5G 4W8  Canada

(604) 484 - 3300

(Name, address, including zip code, and telephone number, including area code, of agent for service)

Copies to:

Approximate date of commencement of proposed sale to the public: From time to time after the effective date of this Registration Statement.

(Approximate date of commencement of proposed sale toStatement, as the public)registrant shall determine.

If the only securities being registered on this Form are being offered pursuant to dividend or interest reinvestment plans, please check the following box.  o☐

If any of the securities being registered on this Form are to be offered on a delayed or continuous basis pursuant to Rule 415 under the Securities Act of 1933, other than securities offered only in connection with dividend or interest reinvestment plans, check the following box.  x☒

If this Form is filed to register additional securities for an offering pursuant to Rule 462(b) under the Securities Act, please check the following box and list the Securities Act registration statement number of the earlier effective registration statement for the same offering.  o☐

If this Form is a post-effective amendment filed pursuant to Rule 462(c) under the Securities Act, check the following box and list the Securities Act registration statement number of the earlier effective registration statement for the same offering.  o☐

If this Form is a registration statement pursuant to General Instruction I.D. or a post-effective amendment thereto that shall become effective upon filing with the Commission pursuant to Rule 462(e) under the Securities Act, check the following box.  o☐

If this Form is a post-effective amendment to a registration statement filed pursuant to General Instruction I.D. filed to register additional securities or additional classes of securities pursuant to Rule 413(b) under the Securities Act, check the following box.  o☐

Indicate by check mark whether the Registrantregistrant is a large accelerated filer, an accelerated filer, a non-accelerated filer, or a smaller reporting company, or an emerging growth company. See the definitions of “large accelerated filer,” “accelerated filer” andfiler,” “smaller reporting company”company,” and “emerging growth company” in Rule 12b-2 of the Exchange Act.

If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 7(a)(2)(B) of the Securities Act. ☐

CALCULATION OF REGISTRATION FEE

The Registrant hereby amends this Registration Statement on such date or dates as may be necessary to delay its effective date until the Registrant shall file a further amendment which specifically states that this Registration Statement shall thereafter become effective in accordance with Section 8(a) of the Securities Act of 1933 or until this Registration Statement shall become effective on such date as the Commission acting pursuant to said Section 8(a), may determine.

The information in this prospectus is not complete and may be changed.  WeThe securities may not sell the securitiesbe sold until the Registration Statement filed with the Securities and Exchange Commission is effective.  This prospectus is not an offer to sell these securities and is not soliciting an offer to buy these securities in any state where the offer or sale is not permitted.

SUBJECT TO COMPLETION, DATED DECEMBER 7, 2015JUNE 3, 2020

PROSPECTUS

$150,000,000250,000,000

Xenon Pharmaceuticals Inc.

Common Shares

Preferred Shares

Warrants

Units

4,394,175 Common Shares

Offered by Selling Securityholders

We may offer and sell from time to time, in one or more series or issuances and on terms that we will determine at the time of the offering, any combination of the securities described in this prospectus, either individually or as units comprised of one or more of the other classes of securities, up to an aggregate amount of $150,000,000.

In addition, selling securityholders to be named in a prospectus supplement may from time to time offer and sell up to 4,394,175 of our common shares. We will not receive any of the proceeds from the sale of our common shares by the selling securityholders.$250,000,000.

This prospectus provides a general description of the securities we may offer.  Each time we or any of the selling securityholders offer and sell securities, we or such selling securityholders will provide specific terms of the securities offered and, if applicable, the selling securityholders, in a supplement to this prospectus.  We may also authorize one or more free writing prospectuses to be provided to you in connection with these offerings.  A prospectus supplement and any free writing prospectus may also add, update or change information contained in this prospectus.  You should carefully read this prospectus, the applicable prospectus supplement, and any related free writing prospectus, as well as the documents incorporated or deemed to be incorporated by reference in this prospectus, before you invest in any of our securities offered hereby.

This prospectus may not be used to consummate a sale of any securities unless it is accompanied by a prospectus supplement.

We or the selling securityholders may offer and sell the securities described in this prospectus and any prospectus supplement to or through one or more underwriters, broker-dealers, agents, directly to purchasers, or through any other means described in this prospectus under “Plan of Distribution” and in supplements to this prospectus in connection with a particular offering of securities.  If any underwriters, dealers or agents are involved in the sale of any of these securities, their names and any applicable purchase price, fee, commission or discount arrangement between or among them will be set forth, or will be calculable from the information set forth, in the applicable prospectus supplement.  The price to the public of such securities and the net proceeds we expect to receive from such sale will also be set forth in a prospectus supplement.

Our common shares are listed on The NASDAQNasdaq Global Market, or NASDAQ,Nasdaq, under the symbol “XENE.” On December 4, 2015,May 29, 2020, the last reported sale price of our common shares on NASDAQNasdaq was $9.05$13.70 per share.  There is currently no market for the other securities we may offer; however, we will provide information in any applicable prospectus supplement regarding any listing of securities other than our common shares on any securities exchange.

We are an “emerging growth company” as defined under the federal securities laws and, as such, have elected to comply with certain reduced public company reporting requirements.

INVESTING IN OUR SECURITIES INVOLVES SIGNIFICANT RISKS.  YOU SHOULD REVIEWPLEASE CAREFULLY READ THE INFORMATION UNDER THE HEADINGS “RISK FACTORS” BEGINNING ON PAGE 4 OF THIS PROSPECTUS AND “ITEM 1A – RISK FACTORS” OF OUR MOST RECENT REPORT ON FORM 10-K OR 10-Q THAT IS INCORPORATED BY REFERENCE IN THE APPLICABLETHIS PROSPECTUS SUPPLEMENT BEFORE INVESTINGYOU INVEST IN OUR SECURITIES.

Neither the Securities and Exchange Commission nor any state securities commission has approved or disapproved of these securities or passed upon the adequacy or accuracy of this prospectus.  Any representation to the contrary is a criminal offense.

The date of this prospectus is                      , 2015.

2020.

Table of Contents

-i-

ABOUT THIS PROSPECTUS

This prospectus is part of a registration statement on Form S-3 that we filed with the United States Securities and Exchange Commission, or the SEC, using a “shelf” registration process.  Under this shelf registration process, we may, from time to time, sell any combination of the securities described in this prospectus in one or more offerings up to an aggregate dollar amount of $150,000,000. In addition, the selling securityholders may from time to time sell up to an aggregate amount of 4,394,175 of our common shares in one or more offerings.$250,000,000.  This prospectus provides you with a general description of the securities we or the selling securityholders may offer.

Each time we or the selling securityholders sell securities, we will provide aone or more prospectus supplementsupplements that will contain specific information about the terms of thatthe offering.  We may also authorize one or more free writing prospectuses to be provided to you that may contain material information relating to these offerings, hereinafter referred to as an issuer free writing prospectus.  The prospectus supplement and any issuer free writing prospectus may also add to, update or change information contained in the prospectus and, accordingly, to the extent inconsistent, information in this prospectus is superseded by the information in the prospectus supplement or the issuer free writing prospectus, as applicable.  You should carefully read this prospectus, any prospectus supplement, and any issuer free writing prospectus, together with the additional information described under the heading “Information Incorporated by Reference.”

The prospectus supplement to be attached to the front of this prospectus may describe, as applicable, the terms of the securities offered; the initial public offering price;price to the public; the price paid for the securities; net proceeds; and the other specific terms related to the offering of the securities.

THIS PROSPECTUS MAY NOT BE USED TO OFFER AND SELL SECURITIES UNLESS IT IS ACCOMPANIED BY A PROSPECTUS SUPPLEMENT.

You should only rely on the information contained or incorporated by reference in this prospectus and any prospectus supplement or issuer free writing prospectus relating to a particular offering.  No person has been authorized to give any information or make any representations in connection with this offering other than those contained or incorporated by reference in this prospectus, any accompanying prospectus supplement and any related issuer free writing prospectus in connection with the offering described herein and therein, and, if given or made, such information or representations must not be relied upon as having been authorized by us.  Neither this prospectus nor any prospectus supplement nor any related issuer free writing prospectus shall constitute an offer to sell or a solicitation of an offer to buy offered securities in any jurisdiction in which it is unlawful for such person to make such an offering or solicitation.  This prospectus does not contain all of the information included in the registration statement.  For a more complete understanding of the offering of the securities, you should refer to the registration statement, including its exhibits.

You should read the entire prospectus and any prospectus supplement and any related issuer free writing prospectus, as well as the documents incorporated by reference into this prospectus or any prospectus supplement or any related issuer free writing prospectus, before making an investment decision.  Neither the delivery of this prospectus or any prospectus supplement or any issuer free writing prospectus nor any sale made hereunder shall under any circumstances imply that the information contained or incorporated by reference herein or in any prospectus supplement or issuer free writing prospectus is correct as of any date subsequent to the date hereof or of such prospectus supplement or issuer free writing prospectus, as applicable.  You should assume that the information appearing in this prospectus, any prospectus supplement, any issuer free writing prospectus, or any document incorporated by reference is accurate only as of the date of the applicable documents, regardless of the time of delivery of this prospectus or any sale of securities.  Our business, financial condition, results of operations and prospects may have changed since that date.

References in this prospectus to the “company,” “we,” “us” and “our” and similar terms or “Xenon” refer to Xenon Pharmaceuticals Inc. and its subsidiary.

-1-

PROSPECTUSPROSPECTUS SUMMARY

This summary description about us and our business highlights selected information containedthat is presented in greater detail elsewhere, or incorporated by reference, in this prospectus or incorporated in this prospectus by reference. This summaryprospectus. It does not contain all of the information that may be important to you should consider before deciding to investand your investment decision. Before investing in our securities. Yousecurities, you should carefully read this entire prospectus, and any applicable prospectus supplement, including each of the documents incorporated herein or therein by reference, before making an investment decision. Investors should carefully consider the informationmatters set forth under the section of this prospectus captioned “Risk Factors” on page 4 and incorporatedthe financial statements and related notes and other information that we incorporate by reference toherein, including our annual reportAnnual Report on Form 10-K and our quarterly reportsQuarterly Reports on Form 10-Q,10-Q. Unless the context indicates otherwise, references in this prospectus to “Xenon Pharmaceuticals Inc.,” “we,” “our” and any amendments thereto.“us” refer, collectively, to Xenon Pharmaceuticals Inc. and its wholly-owned subsidiary.

Overview

We are a clinical-stageclinical stage biopharmaceutical company discovering andcommitted to developing innovative therapeutics to improve the lives of patients with neurological disorders. We are advancing a novel product pipeline of neurology-focused therapies to address areas of high unmet medical need, with a focus on epilepsy. In addition to our proprietary product candidates, we also have partnered programs with several pharmaceutical companies, including Neurocrine Biosciences, Inc., Genentech, a member of the Roche Group, and Flexion Therapeutics, Inc.

Our proprietary product candidates include:

Our clinical stage partnered programs include:

In addition to current product candidates in development and our partnered programs, we intend to commercialize onexpand our own,pipeline from our internal research efforts and for larger market indications that we intend to partner with global pharmaceutical companies.  We have built a core enabling discovery platform formay expand our pipeline through the discoveryacquisition or in-licensing of validated drug targets by studying rare human diseases with extreme traits, including diseases caused by mutations in ion channels, known as channelopathies.  We have an integrated platform that includes in-house capabilities for human genetics, small molecule drug discovery, as well as preclinical and clinical development.

Our business was founded on our proprietary discovery platform, which we refer to as Extreme Genetics.  Extreme Genetics involves the study of families where individuals exhibit inherited severe traits, or phenotypes.  By identifying and characterizing single-gene defects responsible for these phenotypes, we gain insights into human disease biology to better select targets for therapeutic intervention.  Our Extreme Genetics discovery platform has yielded the first approved gene therapyother product in the European Union, or the EU, and a broad development pipeline and multiple pharmaceutical partnerships.  We believe that our Extreme Genetics discovery platform enhances the likelihood of discovering a drug target that has a major effect in humans.  From these discoveries, we can gain an improved understanding of how a drug that modulates the target might act when given to a human.

Our pharmaceutical partners include Teva Pharmaceutical Industries, Ltd., or Teva (through its subsidiary, Ivax International GmbH), Genentech, Inc., or Genentech, and Merck & Co., Inc., or Merck (through its affiliate, Essex Chemie AG).  Our pharmaceutical collaborations have generated in aggregate over $155.0 million in non-equity funding to date with the potential to provide us with over $1.0 billion in future milestone payments, as well as royalties and co-promotion income on product sales.candidates.

Corporate Information

We were incorporated in the Province of British Columbia on November 5, 1996 under the predecessor to the Business Corporations Act (British Columbia) under the name “Xenon Bioresearch Inc.”  We continued from British Columbia to the federal jurisdiction pursuant to Section 187 of the Canada Business Corporations Act, or the CBCA, on May 17, 2000 and concurrently changed our name to “Xenon Genetics Inc.” We registered as an extra-provincial company in British Columbia on July 10, 2000 and changed our name to “Xenon Pharmaceuticals Inc.” on August 24, 2004.  We have no subsidiaries.one wholly-owned subsidiary as of December 31, 2019, Xenon Pharmaceuticals USA Inc., which was incorporated in Delaware on December 2, 2016.  Our principal executive offices are located at 200 – 3650 Gilmore Way, Burnaby, British Columbia, Canada V5G 4W8, and our telephone number is (604) 484-3300.  Our website address is http://www.xenon-pharma.com.  The information on, or that can be accessed through, our website is not incorporated by reference into this prospectus and should not be considered to be a part of this prospectus.  We have included our website address as an inactive textual reference only.

-2-

“Xenon,” the Xenon logo “Extreme Genetics^TM” and other trademarks or service marks of Xenon appearing in this prospectus are trademarked and are the property of Xenon Pharmaceuticals Inc.  This prospectus contains references to our trademarks and service marks and to those belonging to other entities, including “Glybera®,” which is the property of uniQure.entities.  Solely for convenience, trademarks and trade names referred to in this prospectus, including logos, artwork and other visual displays, may appear without the ® or ™ symbols, but such references are not intended to indicate in any way that we will not assert, to the fullest extent under applicable law, our rights or the rights of the applicable licensor to these trademarks and trade names.  We do not intend our use or display of other entities’ trade names, trademarks or service marks to imply a relationship with, or endorsement or sponsorship of us by, any other entity.

-2-

Implications of Being an Emerging Growth Company

We qualify as an “emerging growth company” as defined in the Jumpstart Our Business Startups Act of 2012, or the JOBS Act. An emerging growth company may take advantage of relief from certain reporting requirements and other burdens that are otherwise applicable generally to public companies. As an emerging growth company:

We may use these provisions until the last day of our fiscal year following the fifth anniversary of our initial public offering. However, if certain events occur prior to the end of such five-year period, including if we become a “large accelerated filer,” our annual gross revenues exceed $1.0 billion or we issue more than $1.0 billion of non-convertible debt in any three-year period, we will cease to be an emerging growth company prior to the end of such five-year period. We may choose to take advantage of some but not all of these reduced burdens. To the extent that we take advantage of these reduced burdens, the information that we provide securityholders may be different than you might obtain from other public companies in which you hold equity interests.

The Securities We May Offer

We may offer up to $150,000,000$250,000,000 of common shares, preferred shares, warrants and/or units in one or more offerings and in any combination. In addition, the selling securityholders may sell up to 4,394,175 common shares from time to time incombination, either individually or as units comprised of one or more offerings.of the other classes of securities.  This prospectus provides you with a general description of the securities we and the selling securityholders may offer.  A prospectus supplement, which we will provide each time we or the selling securityholders offer securities, will describe the specific amounts, prices and terms of these securities.

We may sell the securities to or through underwriters, dealers or agents or directly to purchasers or as otherwise set forth in the section of this prospectus captioned “Plan of Distribution.” We, as well as any agents acting on our behalf, reserve the sole right to accept and to reject in whole or in part any proposed purchase of securities. Each prospectus supplement will set forth the names of any underwriters, dealers, agents or other entities involved in the sale of securities described in that prospectus supplement and any applicable fee, commission or discount arrangements with them.

Common Shares

Each holder of one common share is entitled to one vote for each common share on all matters submitted to a vote of the shareholders, including the election of directors.  There are no cumulative voting rights.  Subject to preferences that may be applicable to any then outstanding preferred shares, holders of common shares are entitled to receive ratably those dividends, if any, as may be declared from time to time by our board of directors out of legally available funds.  In the event of our liquidation, dissolution or winding up, holders of common shares will be entitled to share ratably in the net assets legally available for distribution to shareholders after the payment of all of our debts and other liabilities and the satisfaction of any liquidation preference granted to the holders of any then outstanding preferred shares.

Preferred Shares

Our board of directors has the authority, without further action by the shareholders, to issue an unlimited number of preferred shares in one or more series. Subject to the provisions of the CBCA and the provisions of our outstanding Series 1 preferred shares, our board of directors has the discretion to determine the rights, preferences, privileges, restrictions and conditions, including, among others, dividend rights, conversion rights, voting rights, redemption rights, and liquidation preferencespreference of each series of preferred shares. As of March 31, 2020, there were 1,016,000 Series 1 preferred shares outstanding. Any new series of preferred shares authorized by our board of directors will have rights, preferences and privileges that are substantially the same as our Series 1 preferred shares. For additional information regarding our Series 1 preferred shares, see the section of this prospectus titled “Description of Share Capital – Series 1 Preferred Shares.”

Each series of preferred shares will be more fully described in the particular prospectus supplement that will accompany this prospectus, including redemption provisions, rights in the event of our liquidation, dissolution or winding up, dividend and voting rights and rights to convert into common shares.  There are currently noNo rights, privileges, restrictions or conditions attached to a series of preferred shares shall confer on a series a priority in respect of dividends or return of capital over any other series of preferred shares that are then outstanding.

If any cumulative dividends or amounts payable on return of capital in respect of a series of preferred shares are not paid in full, all series of the preferred shares participate ratably in respect of accumulated dividends and return of capital.  

Warrants

We may issue warrants for the purchase of common shares or preferred shares.  We may issue warrants independently or together with other securities.

Units

We may issue units comprised of one or more of the other classes of securities issued by us as described in this prospectus in any combination.  Each unit will be issued so that the holder of the unit is also the holder of each security included in the unit.

-3-

RISK FACTORSFACTORS

An investment in our securities involves a high degree of risk.  The prospectus supplement applicable to each offering of our securities will contain a discussion of the risks applicable to an investment in our securities.  Prior to making a decision about investing in our securities, you should carefully consider the specific factors discussed under the heading “Risk Factors” in the applicable prospectus supplement, together with all of the other information contained or incorporated by reference in the prospectus supplement or appearing or incorporated by reference in this prospectus.  You should also consider the risks, uncertainties and assumptions discussed under “Part I—Item 1A—Risk Factors,” inof our most recent Annual Report on Form 10-K for the fiscal year ended December 31, 2014 and in “Part II—Item 1A—Risk Factors” in our most recent Quarterly ReportsReport on Form 10-Q, and any amendments thereto, all of whichfiled subsequent to such Form 10-K that are incorporated herein by reference, andas may be amended, supplemented or superseded from time to time by other reports we file with the SEC in the future and any prospectus supplement related to a particular offering.  The risks and uncertainties we have described are not the only ones we face.  Additional risks and uncertainties not presently known to us or that we currently deem immaterial may also affect our operations.

SPECIAL NOTE REGARDING FORWARD-LOOKING STATEMENTS

This prospectus, each prospectus supplement and the information incorporated by reference in this prospectus and each prospectus supplement contain certain statements that may constitute forward-looking statements within the meaning of Section 27A of the Securities Act of 1933, as amended, and Section 21E of the Securities Exchange Act of 1934, as amended.  The words “aim,” “anticipate,” “assume,” “believe,” “contemplate,” “continue,” “could,” “due,” “estimate,” “expect,” “goal,” “intend,” “may,” “objective,” “plan,” “predict,” “positioned,” “potential,” “seek,” “should,” “target,” “will,” “would” and similar expressions and variations thereof are intended to identify forward-looking statements, but are not the exclusive means of identifying such statements.  Those statements may appear in this prospectus, any accompanying prospectus supplement and the documents incorporated herein and therein by reference, particularly in the sections entitledcaptioned “Prospectus Summary,” “Risk Factors,” “Management’s Discussion and Analysis of Financial Condition and Results of Operations” and “Business” and include statements regarding the intent, belief or current expectations of Xenon and our management that are subject to known and unknown risks, uncertainties and assumptions.  You are cautioned that any such forward-looking statements are not guarantees of future performance and involve risks and uncertainties, and that actual results may differ materially from those projected in the forward-looking statements as a result of various factors.

Forward-looking statements are subject to certain risks and uncertainties that could cause actual results to differ materially from those anticipated in the forward-looking statements.  Factors that might cause such a difference include, but are not limited to, those described in “Risk Factors”, elsewhere in this prospectus or any applicable prospectus supplement and the documents incorporated by reference in this prospectus.  Forward-looking statements are based on our management’s beliefs and assumptions and on information currently available to our management.  These statements, like all statements in this prospectus, speak only as of their date, and we undertake no obligation to update or revise these statements in light of future developments, except as required by law.

This prospectus, any accompanying prospectus supplement and the documents incorporated herein and therein by reference may also contain estimates and other information concerning our industry that are based on government and industry publications.  This information involves a number of assumptions and limitations, and you are cautioned not to give undue weight to these estimates.  These government and industry publications generally indicate that their information has been obtained from sources believed to be reliable.

RATIO OF EARNINGS TO FIXED CHARGES AND PREFERENCE DIVIDENDS

Any time preferred sharesIn addition, statements that “we believe” and similar statements reflect our beliefs and opinions on the relevant subject. These statements are offered pursuantbased upon information available to us as of the date of this prospectus, and although we will providebelieve such information forms a table setting forthreasonable basis for such statements, such information may be limited or incomplete, and our ratiostatements should not be read to indicate that we have conducted a thorough inquiry into, or review of, earningsall potentially available relevant information. These statements are inherently uncertain and investors are cautioned not to fixed charges and preference dividends on a historical basis in the applicable prospectus supplement, if required.unduly rely upon these statements.

USE OF PROCEEDS

Unless otherwise indicated in the applicable prospectus supplement, we willcurrently expect to use the net proceeds from the sale of securities offered by us pursuant to this prospectus (i) to fund preclinical and clinical development of our product candidates; (ii) to fund genetic research using our Extreme Genetics discovery platform and to fund ion channel drug discovery activities; and (iii) for general corporate purposes, which may include working capital, capital expenditures, and other corporate expenses.

-4-

We may also use a portion of the net proceeds in connection with any exercise of co-development or co-promotion rights under our collaborations; however, no such rights are currently exercisable. In addition, we may also use a portion of the net proceeds to acquire, license andor invest in complementary products, technologies or businesses; however, we currently have no agreements or commitments to complete any such transactions.The expected use of net proceeds of this offering represents our current intentions based on our present plans and business conditions. We cannot specify with certainty all of the particular uses for the net proceeds to be received upon the closing of this offering. Pending these uses, we plan to invest the net proceeds of this offering in treasury bills, corporate bonds, commercial paper, term deposits, bankers acceptances or deposit-based investments including, but not limited to, interest savings accounts. The goal with respect to the investment of these net proceeds is capital preservation and liquidity so that such funds are readily available to fund our operations.

-4-

The amounts and timing of our actual expenditures may vary significantly depending on numerous factors, including cash flows from operations, the anticipated growth of our business, the progress of our development and commercialization efforts and the status and results of our clinical trials, as well as results from any ongoing collaborations and additional collaborations that we may enter into with third parties and any unforeseen cash needs.  As a result, unless otherwise indicated in the prospectus supplement, our management will have broad discretion to allocate the net proceeds of the offerings.  More detailed information regarding use of proceeds will be described in the applicable prospectus supplement.

DIVIDEND POLICY

We will not receivehave never declared or paid any proceeds from the sale ofcash dividends on our common shares byor any other securities.  We currently anticipate that we will retain all available funds and any future earnings, if any, in the selling securityholders.foreseeable future for use in the operation of our business and do not currently anticipate paying cash dividends in the foreseeable future.  Payment of future cash dividends, if any, will be at the discretion of the board of directors, subject to applicable law and will depend on various factors, including our financial condition, operating results, current and anticipated cash needs, the requirements of current or then-existing debt instruments and other factors the board of directors deems relevant.

DESCRIPTION OF SHARE CAPITAL

General

The following is a summary of the material rightsdescription of our common shares and preferred shares, as contained in our articles and by-laws. This summaryshare capital is not a complete description of the share rights associated with our common shares and preferred shares. For more detailed information, please see our articles and by-laws, which are filed as exhibitsincorporated by reference to Exhibit 4.4 to our quarterly reportAnnual Report on Form 10-Q10-K for the periodfiscal year ended September 30, 2014, asDecember 31, 2019, filed on December 15, 2014.  

Our authorized share capital consists of an unlimited number of common shares, each without par value, and an unlimited number of preferred shares, issuable in series, each without par value. Our board of directors is authorized, without shareholder approval except as required by the listing standards of The NASDAQ Global Market, to issue additional shares of our common shares or preferred shares.

Common Shares

Outstanding Shares

As of September 30, 2015, we had 14,344,267 common shares outstanding, held by approximately 196 holders of record.

As of September 30, 2015, we had outstanding options to purchase an aggregate of 1,637,174 common shares pursuant to our equity plans, at a weighted average exercise price of $6.83 per common share.  As of September 30, 2015, 149,492 common shares remain available for future grant or issuance under our 2014 Equity Incentive Plan.

Voting Rights

The holders of our common shares are entitled to one vote for each common share held on all matters submitted to a vote of the shareholders, including the election of directors. Our articles and by-laws do not provide for cumulative voting rights. Because of this, the holders of a plurality of the common shares entitled to vote in any election of directors can elect all of the directors standing for election, if they should so choose.

Dividends

Subject to priority rights that may be applicable to any then outstanding preferred shares, holders of our common shares are entitled to receive dividends, as and when declared by our board of directors in their absolute discretion out of legally available funds.

Liquidation

In the event of our liquidation, dissolution or winding up, holders of our common shares will be entitled to share ratably in the net assets legally available for distribution to shareholders after the payment of all of our debts and other liabilities and the satisfaction of any liquidation preference granted to the holders of any then outstanding preferred shares.

Rights and Preferences

Holders of common shares have no pre-emptive or conversion rights and our common shares have no provisions for redemption or repurchase for cancellation, surrender or sinking or purchase funds. There are no provisions in our articles or by-laws requiring holders of common shares to contribute additional capital. The rights, preferences and privileges of the holders of common shares are subject to and may be adversely affected by, the rights of the holders of any series of preferred shares that we may designate and issue in the future.

-5-

Fully Paid and Nonassessable

All of our outstanding common shares are fully paid and nonassessable. Our board of directors has the authority to issue, without further action by our shareholders, additional common shares.

Preferred Shares

As of September 30, 2015, we had no preferred shares outstanding. Our board of directors has the authority to issue, without further action by our shareholders, an unlimited number of preferred shares, issuable in one or more series, and subject to the provisions of the CBCA, to fix such rights, preferences, privileges, restrictions and conditions thereon, including dividend and voting rights, as our board of directors may determine, and such rights, preferences and privileges, including dividend rights, voting rights and rights relating to the distribution of our assets in the event of liquidation, dissolution or winding up of our affairs, whether, voluntary or involuntary, or any other distribution of our assets among our shareholders for the purpose of winding up our affairs, may be superior to those of our common shares. The issuance of preferred shares, while providing flexibility in connection with possible acquisitions and other corporate purposes, could adversely affect the voting power of holders of common shares and the likelihood that such holders will receive dividend payments and payments upon liquidation. In addition, the issuance of preferred shares could, among other things, have the effect of delaying, deferring or preventing a change in control of our company or other corporate action and could adversely affect the market price of our common shares and the voting and other rights of the holders of our common shares.

Registration Rights

Under our amended and restated investor rights agreement, as amended, the holders of approximately 4,394,175 common shares or their transferees have the right to require us to register the offer and sale of their common shares, or to include their common shares in any registration statement we file, in each case as described below.

Demand Registration Rights

The holders of a majority of our common shares having registration rights have the right to demand that we file a registration statement for the offer and sale of at least such number of common shares, or a lesser amount if the anticipated offering proceeds would exceed CAD$5,000,000, subject to specified limitations. We are only obligated to effect two registrations in connection with the exercise of demand registration rights. These registration rights are subject to specified conditions and limitations, including the right of the underwriters to limit the number of common shares included in any such registration under certain circumstances and our ability to defer the filing of a registration statement with respect to an exercise of such demand registration rights for up to 90 days under certain circumstances.

Form S-3 Registration Rights

Each holder of common shares having registration rights has the right to demand that we file a registration statementSEC on Form S-3 so long as the aggregate amount of common shares to be offered and sold under such registration statement on Form S-3 is at least CAD$500,000. We are not obligated to file any registration statements within 180 days following the effective date of a registration pertaining to a public offering or to effect more than two registrations on Form S-3 in any 12-month period. These registration rights are subject to specified conditions and limitations, including our ability to defer the filing of a registration statement with respect to an exercise of such Form S-3 registration rights for up to 90 days under certain circumstances.

Piggyback Registration Rights

If we propose to register the offer and sale of any of our securities under the Securities Act either for our own account or for the account of other shareholders, a shareholder with registration rights will have the right, subject to certain exceptions, to include their common shares in the registration statement. These registration rights are subject to specified conditions and limitations, including the right of the underwriters to limit the number of common shares included in any such registration statement under certain circumstances, but not below 25% of the total number of common shares covered by the registration statement.

Expenses of Registration

We will pay all expenses relating to any demand registrations, Form S-3 registrations and piggyback registrations, other than underwriting discounts and selling commissions.

-6-

March 9, 2020Termination.

The registration rights terminate upon the earliest of (1) the date that is four years after the closing of our initial public offering and (2) as to a given holder of registration rights, if (a) we are subject to the public company reporting requirements of the Securities Exchange Act of 1934, (b) such holder holds less than 1% of our outstanding common shares and (c) such holder can sell all of such holder’s registrable securities in a three month-period pursuant to Rule 144 promulgated under the Securities Act.

Corporate Governance

Under the CBCA, we are required to hold a general meeting of our shareholders at least once every year at a time and place determined by our board of directors, provided that the meeting must not be held later than 15 months after the preceding annual general meeting and no later than six months after the end of the preceding financial year. The CBCA requires that meetings of shareholders shall be held at any place within Canada as our board of directors may from time to time determine. A notice to convene a meeting, specifying the date, time and location of the meeting must be sent to shareholders, to each director and the auditor not less than 21 days prior to the meeting or such other minimum period as required by the applicable securities laws. Under the CBCA, shareholders entitled to notice of a meeting may waive or reduce the period of notice for that meeting, provided applicable securities laws requirements are met.

Under the CBCA, all business transacted at a special meeting of shareholders and all business transacted at an annual meeting of shareholders, except consideration of the financial statements, auditor’s report, election of directors and re-appointment of the incumbent auditor, is deemed to be special business. Notice of a meeting of shareholders at which special business is to be transacted shall state (a) the nature of that business in sufficient detail to permit the shareholder to form a reasoned judgment thereon; and (b) the text of any special resolution to be submitted to the meeting.

Under the CBCA, our board of directors has the power at any time to call a special meeting of our shareholders. In addition, the holders of not less than 5% of our shares that carry the right to vote at a meeting sought to be held can also requisition our board of directors to call a meeting of our shareholders for the purposes stated in the requisition. If our board of directors does not call the meeting within 21 days after receiving the requisition, our shareholders can call the meeting and the expenses reasonably incurred by such shareholders in requisitioning, calling and holding the meeting must be reimbursed by us.

Those entitled to vote at a meeting are entitled to attend meetings of our shareholders. Every shareholder entitled to vote may appoint a proxyholder to attend the meeting in the manner and to the extent authorized and with the authority conferred by the proxy. Directors, auditors, legal counsels, secretary (if any), and any other persons invited by the chair of the meeting or with the consent of those at the meeting are entitled to attend any meeting of our shareholders but will not be counted in quorum or be entitled to vote at the meeting unless he or she or it is a shareholder or proxyholder entitled to vote at the meeting.

Certain Takeover Bid Requirements

Unless such offer constitutes an exempt transaction, an offer made by a person, an “offeror”, to acquire outstanding shares of a Canadian entity that, when aggregated with the offeror’s holdings (and those of persons or companies acting jointly with the offeror), would constitute 20% or more of the outstanding shares in a class, would be subject to the take-over provisions of Canadian securities laws. The foregoing is a limited and general summary of certain aspects of applicable securities law in the provinces and territories of Canada, all in effect as of the date hereof.

In addition to those takeover bid requirements noted above, the acquisition of our shares may trigger the application of statutory regimes including among others, the Investment Canada Act (Canada) and the Competition Act (Canada).

Limitations on the ability to acquire and hold our common shares may be imposed by the Competition Act (Canada). This legislation permits the Commissioner of Competition, or the Commissioner, to review any acquisition of control over or of a significant interest in us. This legislation grants the Commissioner jurisdiction, for up to one year, to challenge this type of acquisition before the Canadian Competition Tribunal on the basis that it would, or would be likely to, substantially prevent or lessen competition in any market in Canada.

This legislation also requires any person who intends to acquire our common shares to file a notification with the Canadian Competition Bureau if certain financial thresholds are exceeded and if that person (and their affiliates) would hold more than 20% of our common shares. If a person already owns 20% or more of our common shares, a notification must be filed when the acquisition of additional shares would bring that person’s holdings to over 50%. Where a notification is required, the legislation prohibits completion of the acquisition until the expiration of a statutory waiting period, unless the Commissioner provides written notice that the acquisition will not be challenged.

-7-

There is no limitation imposed by Canadian law or our articles on the right of non-residents to hold or vote our common shares, other than those imposed by the Investment Canada Act.

The Investment Canada Act requires any person that is a “non-Canadian” (as defined in the Investment Canada Act) who acquires control of an existing Canadian business, where the acquisition of control is not a reviewable transaction, to file a notification with Industry Canada. The Investment Canada Act generally prohibits the implementation of a reviewable transaction unless, after review, the relevant minister is satisfied that the investment is likely to be of net benefit to Canada. Under the Investment Canada Act, the acquisition of control of us (either through the acquisition of our common shares or all or substantially all our assets) by a non-Canadian investor who is a World Trade Organization member country investor, including a U.S. investor, but not a state-owned enterprise, would be reviewable only if our enterprise value (as determined pursuant to the Investment Canada Act) exceeds CAD$600.0 million (which threshold will rise to CAD$800.0 million starting on April 24, 2017 and CAD$1.0 billion starting on April 24, 2019, and thereafter this threshold will increase on the basis of a prescribed formula in the Investment Canada Act to reflect changes in the Canadian gross domestic product).  If the acquisition of control of us is by a state-owned enterprise that is a non-Canadian who is a World Trade Organization member country investor, including a U.S. investor, the acquisition of control would be reviewable only if the value of our assets was equal to or greater than a specified amount which is CAD$369.0 million for 2015. The threshold amount is subject to an annual adjustment on the basis of a prescribed formula in the Investment Canada Act to reflect changes in Canadian gross domestic product.

The acquisition of a majority of the voting interests of an entity is deemed to be acquisition of control of that entity. The acquisition of less than a majority but one-third or more of the voting shares of a corporation or an equivalent undivided ownership interest in the voting shares of a corporation is presumed to be an acquisition of control of that corporation unless it can be established that, on the acquisition, the corporation is not controlled in fact by the acquirer through the ownership of voting shares. The acquisition of less than one-third of the voting shares of a corporation is deemed not to be an acquisition of control of that corporation. Certain transactions in relation to our common shares would be exempt from review by the Investment Canada Act including:

Under the new national security regime in the Investment Canada Act, review on a discretionary basis may also be undertaken by the federal government in respect of a much broader range of investments by a non-Canadian to “acquire, in whole or in part, or to establish an entity carrying on all or any part of its operations in Canada.” The relevant test is whether such an investment by a non-Canadian could be “injurious to national security.” The minister responsible for the Investment Canada Act has broad discretion to determine whether an investor is a non-Canadian and may be subject to national security review. Review on national security grounds is at the discretion of the federal government and may occur on a pre- or post-closing basis.

There is no law, governmental decree or regulation in Canada that restricts the export or import of capital or which would affect the remittance of dividends or other payments by us to non-Canadian holders of our common shares or preferred shares, other than withholding tax requirements.

Neither our articles nor by-laws contain any change of control limitations with respect to a merger, acquisition or corporate restructuring that involves us.

This summary is not a comprehensive description of relevant or applicable considerations regarding such requirements and, accordingly, is not intended to be, and should not be interpreted as, legal advice to any prospective purchaser and no representation with respect to such requirements to any prospective purchaser is made. Prospective investors should consult their own Canadian legal advisors with respect to any questions regarding securities law in the provinces and territories of Canada.

Actions Requiring a Special Majority

Under the CBCA, certain corporate actions require the approval of a special majority of shareholders, meaning holders of shares representing not less than 66 ⅔% of those votes cast in respect of a shareholder vote addressing such matter. Those items requiring the approval of a special majority generally relate to fundamental changes with respect to our business, and include among others, resolutions: (i) amending our articles; (ii) approving an amalgamation; (iii) approving a continuance; and (iv) providing for a sale, lease or exchange of all or substantially all of our property.

-8-

Advance Notice Procedures and Shareholder Proposals

Under the CBCA, shareholders may make proposals for matters to be considered at the annual general meeting of shareholders. Such proposals must be sent to us in advance of any proposed meeting by delivering a timely written notice in proper form to our registered office in accordance with the requirements of the CBCA. The notice must include information on the business the shareholder intends to bring before the meeting.

In addition, our by-laws require that shareholders provide us with advance notice of their intention to nominate any persons, other than those nominated by management, for election to our board of directors at a meeting of shareholders.

These provisions could have the effect of delaying until the next shareholder meeting the nomination of certain persons for director that are favored by the holders of a majority of our outstanding voting securities.

Ownership and Exchange Controls

There is currently no law, governmental decree or regulation in Canada that restricts the export or import of capital, or which would affect the remittance of dividends, interest or other payments by us to non-resident holders of our common shares, other than withholding tax requirements.

There is currently no limitation imposed by Canadian law or our articles or by-laws on the right of non-residents to hold or vote our common shares, other than those imposed by the Investment Canada Act and the Competition Act (Canada). These acts will generally not apply except where a control of an existing Canadian business or company, which has Canadian assets or revenue over a certain threshold, is acquired and will not apply to trading generally of securities listed on a stock exchange.

Transfer Agent and Registrar

The transfer agent and registrar for our common shares is American Stock Transfer & Trust Company, LLC, or AST. The transfer agent and registrar’s address is 6201 15th Avenue, Brooklyn, NY 11219. The transfer agent’s telephone number is (800) 937-5449.  Additionally, in compliance with the CBCA, we have retained CST Trust Company, an affiliate of AST, to act as our Canadian transfer agent and registrar.  CST Trust Company’s address is 1066 West Hastings Street, Vancouver, BC  V6E 3X1, and its telephone number is (604) 235-3703.

Listing

Our common shares are listed on NASDAQ under the symbol “XENE.”

DESCRIPTION OF THE WARRANTS

We may issue warrants for theto purchase of ourpreferred shares or common shares. We may offer warrants separately or together with one or more additional warrants, preferred shares or common shares, or any combination thereof. Warrantsof those securities in the form of units, as described in the applicable prospectus supplement. If we issue warrants as part of a unit, the applicable prospectus supplement will specify whether those warrants may be issued independentlyseparated from the other securities in the unit prior to the expiration date of the warrants. The applicable prospectus supplement will also describe the following terms of any warrants:

-5-

-9-

Holders of warrants will not be entitled:

This summary of certain provisions of the warrants is not complete.  For the terms of a particular series of warrants, you should refer to the prospectus supplement for that series of warrants and the warrant agreement for that particular series.

DESCRIPTION OF THE UNITS

We may issue units comprised of onecomprising two or more of the other classes of securities described in this prospectus in any combination. The following description sets forth certain general terms and provisions of the units that we may offer pursuant to this prospectus. The particular terms of the units and the extent, if any, to which the general terms and provisions may apply to the units so offered will be described in the applicable prospectus supplement.

Each unit will be issued so that the holder of the unit is also the holder of each security included in the unit. Thus, the holder of a unit will have the rights and obligations of a holder of each included security. TheUnits will be issued pursuant to the terms of a unit agreement, which may provide that the securities included in the unit may not be held or transferred separately at any time or at any time before a specified date. A copy of the forms of the unit agreement and the unit certificate relating to any particular issue of units will be filed with the SEC each time we issue units, and you should read those documents for provisions that may be issued underimportant to you. For more information on how you can obtain copies of the forms of the unit agreements to be entered into between usagreement and athe related unit agent, as detailed incertificate, see the section of this prospectus captioned “Where You Can Find More Information.”

The prospectus supplement relating to any particular issuance of units will describe the terms of those units, being offered. The prospectus supplement will describe:including, to the extent applicable, the following:

-6-

The descriptions of the units in this prospectusor the securities comprising the units;

PLAN OF DISTRIBUTION

We and/or the selling securityholders, if applicable, may sell the securities offered through this prospectus (1) to or through underwriters or dealers, (2) directly to purchasers, including our affiliates, (3) through agents, or (4) through a combination of any these methods.  The securities may be distributed at a fixed price or prices, which may be changed, market prices prevailing at the time of sale, prices related to the prevailing market prices, or negotiated prices.

The prospectus supplement relating to any offering will include the following information:

In addition, the manner in which we may sell some or all of the securities covered by this prospectus includes, without limitation, through:

We may engage in at-the-market offerings into an existing trading market in accordance with Rule 415(a)(4). Any at-the-market offering will be through an underwriter or underwriters acting as principal or agent for us. in the manner described below under “—At-the-Market Offerings.”

-7-

Sale through Underwriters or Dealers

If underwriters are used in the sale, the underwriters will acquire the securities for their own account, including through underwriting, purchase, security lending or repurchase agreements with us.  The underwriters may resell the securities from time to time in one or more transactions, including negotiated transactions.  Underwriters may sell the securities in order to facilitate transactions in any of our other securities (described in this prospectus or otherwise), including other public or private transactions and short sales.  Underwriters may offer securities to the public either through underwriting syndicates represented by one or more managing underwriters or directly by one or more firms acting as underwriters.  Unless otherwise indicated in the prospectus supplement, the obligations of the underwriters to purchase the securities will be subject to certain conditions, and the underwriters will be obligated to purchase all the offered securities if they purchase any of them.them (other than any securities purchased upon exercise of any option to purchase additional securities). In connection with any offering of securities pursuant to this prospectus, underwriters may have an option to purchase additional securities from us. We will provide information regarding any such option to purchase additional securities from us in the applicable prospectus supplement.  The underwriters may change from time to time any initial public offering price and any discounts or concessions allowed or reallowed or paid to dealers.  The prospectus supplement will include the names of the principal underwriters the respective amount of securities underwritten, the nature of the obligation of the underwriters to take the securities and the nature of any material relationship between an underwriter and us.

Some or all of the securities that we offer through this prospectus may be new issues of securities with no established trading market.  Any underwriters to whom we sell securities for public offering and sale may make a market in those securities, but they will not be obligated to do so and they may discontinue any market making at any time without notice.  Accordingly, we cannot assure you of the liquidity of, or continued trading markets for, any securities offered pursuant to this prospectus.

-11-

If dealers are used in the sale of securities offered through this prospectus, we or the selling securityholders will sell the securities to them as principals.  They may then resell those securities to the public at varying prices determined by the dealers at the time of resale.  The prospectus supplement will include the names of the dealers and the terms of the transaction.

Direct Sales and Sales through Agents

We or the selling securityholders may sell the securities offered through this prospectus directly.  In this case, no underwriters or agents would be involved.  Such securities may also be sold through agents designated from time to time.  The applicable prospectus supplement will name any agent involved in the offer or sale of the offered securities and will describe any commissions payable to the agent by us or the selling securityholders.us.  Unless otherwise indicated in the prospectus supplement, any agent will agree to use its reasonable best efforts to solicit purchases for the period of its appointment.

We or the selling securityholders may sell the securities directly to institutional investors or others who may be deemed to be underwriters within the meaning of the Securities Act with respect to any sale of those securities.  The terms of any such sales will be described in the prospectus supplement.

Delayed Delivery Contracts

If so indicated in the applicable prospectus supplement, we will authorize underwriters or other persons acting as our agents to solicit offers by certain institutions to purchase securities from us pursuant to delayed delivery contracts providing for payment and delivery on the date stated in the prospectus supplement. Each contract will be for an amount not less than, and the aggregate amount of securities sold pursuant to such contracts shall not be less nor more than, the respective amounts stated in the prospectus supplement. Institutions with whom the contracts, when authorized, may be made include commercial and savings banks, insurance companies, pension funds, investment companies, educational and charitable institutions and other institutions, but shall in all cases be subject to our approval. Delayed delivery contracts will not be subject to any conditions except that:

The underwriters and other persons acting as agents will not have any responsibility in respect of the validity or performance of delayed delivery contracts.

Certain agents, underwriters and dealers, and their associates and affiliates may be customers of, have borrowing relationships with, engage in other transactions with, and/or perform services, including investment banking services, for us or one or more of our respective affiliates in the ordinary course of business.

-8-

At-the-Market Offerings

To the extent that we make sales through one or more underwriters or agents in at-the-market offerings, we will do so pursuant to the terms of a sales agency financing agreement or other at-the-market offering arrangement between us, on one hand, and the underwriters or agents, on the other. If we engage in at-the-market sales pursuant to any such agreement, we will issue and sell our securities through one or more underwriters or agents, which may act on an agency basis or a principal basis. During the term of any such agreement, we may sell securities on a daily basis in exchange transactions or otherwise as we agree with the underwriters or agents. Any such agreement will provide that any securities sold will be sold at prices related to the then prevailing market prices for our securities. Therefore, exact figures regarding proceeds that will be raised or commissions to be paid cannot be determined as of the date of this prospectus. Pursuant to the terms of the agreement, we may agree to sell, and the relevant underwriters or agents may agree to solicit offers to purchase, blocks of our common stock or other securities. The terms of any such agreement will be set forth in more detail in the applicable prospectus or prospectus supplement.

Market Making, Stabilization, and Other Transactions and Settlement

In order to facilitate the offering of the securities, any underwriters may engage in transactions that stabilize, maintain or otherwise affect the price of the securities or any other securities the prices of which may be used to determine payments on such securities. Specifically, any underwriters may over-allot in connection with the offering, creating a short position for their own accounts. In addition, to cover over-allotments or to stabilize the price of the securities or of any such other securities, the underwriters may bid for, and purchase, the securities or any such other securities in the open market. Finally, in any offering of the securities through a syndicate of underwriters, the underwriting syndicate may reclaim selling concessions allowed to an underwriter or a dealer for distributing the securities in the offering if the syndicate repurchases previously distributed securities in transactions to cover syndicate short positions, in stabilization transactions or otherwise. Any of these activities may stabilize or maintain the market price of the securities above independent market levels. Any such underwriters are not required to engage in these activities and may end any of these activities at any time.

Under Rule 15c6-1 of the Exchange Act, trades in the secondary market generally are required to settle in two business days, unless the parties to any such trade expressly agree otherwise. The applicable prospectus supplement may provide that the original issue date for your securities may be more than two scheduled business days after the trade date for your securities. Accordingly, in such a case, if you wish to trade securities on any date prior to the third business day before the original issue date for your securities, you will be required, by virtue of the fact that your securities initially are expected to settle in more than three scheduled business days after the trade date for your securities, to make alternative settlement arrangements to prevent a failed settlement.

Unless the applicable prospectus supplement states otherwise, each offered security will be a new issue and will have no established trading market, with the exception of our common shares.  We may elect to list any offered securities on an exchange.  Any underwriters that we or the selling securityholders use in the sale of offered securities may make a market in such securities, but may discontinue such market making at any time without notice.  Accordingly, we cannot assure you of the liquidity of, or continued trading markets for, any securities offered pursuant to this prospectus.

Any underwriter may also engage in stabilizing transactions, syndicate covering transactions and penalty bids in accordance with Rule 104 under the Securities Exchange Act of 1934, as amended. Stabilizing transactions involve bids to purchase the underlying security in the open market for the purpose of pegging, fixing or maintaining the price of the securities. Syndicate covering transactions involve purchases of the securities in the open market after the distribution has been completed in order to cover syndicate short positions.

Penalty bids permit the underwriters to reclaim a selling concession from a syndicate member when the securities originally sold by the syndicate member are purchased in a syndicate covering transaction to cover syndicate short positions. Stabilizing transactions, syndicate covering transactions and penalty bids may cause the price of the securities to be higher than it would be in the absence of the transactions. The underwriters may, if they commence these transactions, discontinue them at any time.

Derivative Transactions and Hedging

We, the underwriters or other agents may engage in derivative transactions involving the securities.  These derivatives may consist of short sale transactions and other hedging activities.  The underwriters or agents may acquire a long or short position in the securities, hold or resell securities acquired and purchase options or futures on the securities and other derivative instruments with returns linked to or related to changes in the price of the securities.  In order to facilitate these derivative transactions, we may enter into security lending or repurchase agreements with the underwriters or agents.  The underwriters or agents may effect the derivative transactions through sales of the securities to the public, including short sales, or by lending the securities in order to facilitate short sale transactions by others.  The underwriters or agents may also use the securities purchased or borrowed from us or others (or, in the case of derivatives, securities received from us in settlement of those derivatives) to directly or indirectly settle sales of the securities or close out any related open borrowings of the securities.

Electronic Auctions

We or the selling securityholders may also make sales through the Internet or through other electronic means.  Since we or the selling securityholders may from time to time elect to offer securities directly to the public, with or without the involvement of agents, underwriters or dealers, utilizing the Internet or other forms of electronic bidding or ordering systems for the pricing and allocation of such securities, you should pay particular attention to the description of that system we will provide in a prospectus supplement.

-9-

Such electronic system may allow bidders to directly participate, through electronic access to an auction site, by submitting conditional offers to buy that are subject to acceptance by us, and which may directly affect the price or other terms and conditions at which such securities are sold.  These bidding or ordering systems may present to each bidder, on a so-called “real-time” basis, relevant information to assist in making a bid, such as the clearing spread at which the offering would be sold, based on the bids submitted, and whether a bidder’s individual bids would be accepted, prorated or rejected.

-12-

Upon completion of such an electronic auction process, securities will be allocated based on prices bid, terms of bid or other factors.  The final offering price at which securities would be sold and the allocation of securities among bidders would be based in whole or in part on the results of the Internet or other electronic bidding process or auction.

General Information

Agents, underwriters, and dealers may be entitled, under agreements entered into with us, to indemnification by us or the selling securityholders against certain liabilities, including liabilities under the Securities Act.  Agents,Our agents, underwriters, and dealers, and underwritersor their affiliates, may be customers of, engage in transactions with or perform services for us, in the ordinary course of their businesses.business. In no event will the total amount of compensation paid to the agents, underwriters and dealers upon completion of any offering exceed 8.0% of the gross proceeds of such offering.

MATERIAL INCOME TAX CONSIDERATIONS

The applicable prospectus supplement may describe material U.S. federal income tax consequences of the acquisition, ownership and disposition of any of the securities offered by such prospectus supplement by an investor who is subject to U.S. federal taxation.

The applicable prospectus supplement may also describe material Canadian federal income tax considerations generally applicable to investors described therein of purchasing, holding and disposing of securities offered by such prospectus supplement, including, in the case of an investor who is not a resident of Canada, Canadian non-resident withholding tax considerations.

You should read the tax discussion in any prospectus supplement with respect to a particular offering and consult your own tax advisors with respect to the specific tax consequences of the acquisition, ownership and disposition of the securities offered by such prospectus supplement, including the applicability and effect of state, local and non-U.S. or Canadian tax laws, as well as U.S. and Canadian federal tax laws.

LEGAL MATTERS

We are being represented by Wilson Sonsini Goodrich & Rosati, Professional Corporation, Palo Alto, California.  Certain legal matters relating to the securities offered by this prospectus under Canadian laws will be passed upon for us by McCarthy TétraultBlake, Cassels & Graydon LLP, Vancouver, British Columbia.  As of the date of this prospectus, the members and associates of Wilson Sonsini Goodrich & Rosati, Professional Corporation, as a group, own less than 1% of our outstanding securities and the partners and associates of McCarthy TétraultBlake, Cassels & Graydon LLP, as a group, own less than 1% of our outstanding securities. Additional legal matters may be passed on for us, or any underwriters, dealers or agents, by counsel that we will name in the applicable prospectus supplement.

EXPERTS

The consolidated financial statements of Xenon Pharmaceuticals Inc. as of December 31, 20142019 and 2013,2018, and for each of the years in the three-yeartwo-year period ended December 31, 2014,2019, and management’s assessment of the effectiveness of internal control over financial reporting as of December 31, 2019 have been incorporated by reference herein in reliance upon the reportreports of KPMG LLP, independent registered public accounting firm, also incorporated by reference herein, and upon the authority of said firm as experts in accounting and auditing. KPMG LLP have confirmed with respectThe audit report covering the December 31, 2019 financial statements refers to Xenon Pharmaceuticals Inc., that they are independent within the meaning of the relevant rules and related interpretations prescribed by the relevant professional bodies in Canada and any applicable legislation or regulations and also that they are independent accountants with respecta change to the company under all relevant US professional and regulatory standards.accounting for leases at January 1, 2019 upon the adoption of ASU 2016-02, Leases (Topic 842).

WHERE YOU CAN FIND MORE INFORMATION

We file annual, quarterly and other reports, proxy statements and other information with the SEC.  Our SEC filings are available to the public over the Internet at the SEC’s website at http://www.sec.gov.  You may also read and copy any document we file at the SEC’s Public Reference Room at 100 F Street, NE, Washington, D.C. 20549. Please call the SEC at 1-800-SEC-0330 for further information on the Public Reference Room. Our Annual Report on Form 10-K, Quarterly Reports on Form 10-Q,, and Current Reports on Form 8-K, including any amendments to those reports, and other information that we file with or furnish to the SEC pursuant to Section 13(a) or 15(d) of the Exchange Act can also be accessed free of charge through the Internet.  These filings will be available as soon as reasonably practicable after we electronically file such material with, or furnish it to, the SEC. You may also access these filings through our website at www.xenon-pharma.com.

-10-

-13-

We have filed with the SEC a registration statement under the Securities Act of 1933 relating to the offering of these securities.  The registration statement, including the attached exhibits, contains additional relevant information about us and the securities.  This prospectus does not contain all of the information set forth in the registration statement.  You can obtain a copy of the registration statement, at prescribed rates, from the SEC at the address listedas discussed above.  The registration statement and the documents referred to below under “Incorporation by Reference” are also available on our Internet website, www.xenon-pharma.com.  We have not incorporated by reference into this prospectus the information on our website, and you should not consider it to be a part of this prospectus.

Forms of any documents establishing the terms of the offered securities are filed as exhibits to the registration statement of which this prospectus forms a part or under cover of a Current Report on Form 8-K and incorporated in this prospectus by reference. Statements in this prospectus or any prospectus supplement about these documents are summaries and each statement is qualified in all respects by reference to the document to which it refers. You should read the actual documents for a more complete description of the relevant matters.

INFORMATION INCORPORATED BY REFERENCE

The SEC allows us to incorporate by reference into this prospectus certainmuch of the information that we file with it,the SEC, which means that we can disclose important information to you by referring you to those publicly available documents.  The information incorporatedthat we incorporate by reference in this prospectus is considered to be a part of this prospectus, and information thatprospectus. Because we file laterare incorporating by reference future filings with the SEC, will automatically updatethis prospectus is continually updated and those future filings may modify or supersede some of the information containedincluded or incorporated by reference in this prospectus. This means that you must look at all of the SEC filings that we incorporate by reference to determine if any of the statements in this prospectus andor in any accompanyingdocument previously incorporated by reference have been modified or superseded.  This prospectus supplement. We incorporateincorporates by reference the documents listed below thatand any future filings we have previously filedmake with the SEC:SEC under Sections 13(a), 13(c), 14 or 15(d) of the Exchange Act (in each case, other than those documents or the portions of those documents furnished pursuant to Items 2.02 or 7.01 of any Current Report on Form 8-K and, except as may be noted in any such Form 8-K, exhibits filed on such form that are related to such information), until the offering of the securities under the registration statement of which this prospectus forms a part is terminated or completed:

We also incorporate by reference into this prospectus additional documents (other than current reports furnished under Item 2.02 or Item 7.01 of Form 8-K and exhibits on such form that are related to such items) that we may file with the SEC under Sections 13(a), 13(c), 14 or 15(d) of the Exchange Act prior to the completion or termination of the offering of the securities described in this prospectus, including all such documents we may file with the SEC after the date of the initial registration statement and prior to the effectiveness of the registration statement, but excluding any information deemed furnished and not filed with the SEC. Any statements contained in a previously filed document incorporated by reference into this prospectus is deemed to be modified or superseded for purposes of this prospectus to the extent that a statement contained in this prospectus, or in a subsequently filed document also incorporated by reference herein, modifies or supersedes that statement.

You should rely only on the information incorporated by reference or provided in this prospectus. Neither we nor the selling securityholders have authorized anyone else to provide you with different information. You should not assume that the information in this prospectus is accurate as of any date other than the date of this prospectus or the date of the documents incorporated by reference in this prospectus.

We will provide to each person, including any beneficial owner, to whom this prospectus is delivered, upon written or oral request, at no cost to the requester, a copy of any and all of the information that is incorporated by reference in this prospectus.

Requests for such documents should be directed to:

Xenon Pharmaceuticals Inc.

Attn: Investor Relations

200 – 3650 Gilmore Way

Burnaby, BC  V5G 4W8

Canada

(604) 484-3300

You may also access the documents incorporated by reference in this prospectus through our website at www.xenon-pharma.com.  Except for the specific incorporated documents listed above, no information available on or through our website shall be deemed to be incorporated in this prospectus or the registration statement of which it forms a part.

-11-

$250,000,000

-14-

$150,000,000

Xenon Pharmaceuticals Inc.

Common Shares

Preferred Shares

Warrants

Units

4,394,175 Common Shares

Offered by Selling Securityholders

PROSPECTUS

, 2015  

2020

Part II

Information Not Required in Prospectus

Item 14.  Other Expenses of Issuance and Distribution

The following table sets forth the estimated costs and expenses (other than the actual SEC registration fee), other than underwriting discounts and commissions, payable by the Registrant in connection with the sale of the securities being registered.

*These fees and expenses depend on the securities offered and the number of issuances, and accordingly cannot be estimated as of the date of this prospectus.

Item 15.  Indemnification of Directors and Officers

Under the Canada Business Corporations Act, or CBCA, we may indemnify our current or former directors or officers or any other individuals who act or have acted at our request as a director or officer, or an individual acting in a similar capacity, of another entity, against all costs, charges, and expenses, including an amount paid to settle an action or satisfy a judgment, reasonably incurred by the individual in respect of any civil, criminal, administrative, investigative or other proceeding in which the individual is involved because of his or her association with us or the other entity.  The CBCA also provides that we may advance moneys to a director, officer or other individual for costs, charges and expenses reasonably incurred in connection with such a proceeding.  The individual shall repay the moneys to us if indemnification of the individual is ultimately prohibited under the CBCA, as described below.

Indemnification is prohibited under the CBCA unless the individual:

Our by-laws require us to indemnify each of our directors, officers, former directors and officers and persons who act or acted at our request as a director or officer, or in a similar capacity, of a body corporate.  We will indemnify such individual against all costs, charges and expenses, including an amount paid to settle an action or proceeding to which the individual is made a party by reason of being or having been a director of officer of us or such body corporate.  Our by-laws also require us to, with the approval of a court, indemnify such individual referred to above, in respect of an action by or on behalf of us or such body corporate to procure a judgment in its favor, to which the individual is made a party by reason of being or having been a director or an officer of us or such body corporate, against all costs, charges and expenses reasonably incurred by him in connection with such action.  However, we shall not indemnify such individual if the individual did not act honestly and in good faith with a view to our best interests or, in the case of a criminal or administrative action or proceeding that is enforced by a monetary penalty, the individual did not have reasonable grounds for believing that his or her conduct was lawful.

Our by-laws authorize us, with the approval of our board of directors, to purchase and maintain insurance for the benefit of each of our current or former directors or officers and each person who acts or acted at our request as a director or officer of another entity, against any liability incurred by him or her.

II-1

We have indemnification agreements with each of our directors and certain officers.  As provided by our by-laws, these agreements, among other things, indemnify each director and officer to the fullest extent permitted by Canadian law, including indemnification of all costs, charges and expenses reasonably incurred by such person in any action or proceeding, including any action or proceeding by or in right of us, arising out of the person’s services as a director or officer; provided that, we will not indemnify such individual if, among other things, he or she did not act honestly and in good faith with a view to our best interests and, in the case of a criminal or penal action, the individual did not have reasonable grounds for believing that his or her conduct was lawful.

We have purchased insurance policies which, within the limits and subject to the terms and conditions thereof, cover certain expenses and liabilities that may be incurred by our directors and officers in connection with proceedings that may be brought against them as a result of an act or omission committed or suffered while acting as a director or officer.

Insofar as indemnification of liabilities arising under the Securities Act 1933, as amended, may be permitted to members of our board of directors, officers or persons controlling us pursuant to the foregoing provisions, we have been informed that, in the opinion of the SEC, such indemnification is against public policy as expressed in the Securities Act of 1933, as amended, and is therefore unenforceable.

Item 16.  Exhibits

A list of exhibits filed herewith is contained in the exhibit index that immediately precedes such exhibitsExhibit Index

Item 17.  Undertakings

provided, however, that paragraphs (a)(1)(i), (a)(1)(ii), and (a)(1)(iii) of this section do not apply if the information required to be included in a post-effective amendment by those paragraphs is contained in reports filed with or furnished to the SECCommission by the Registrant pursuant to Sectionsection 13 or Sectionsection 15(d) of the Securities Exchange Act of 1934 that are incorporated by reference in the registration statement, or is contained in a form of prospectus filed pursuant to Rule 424(b) that is part of the registration statement.

II-2

II-3(iii)The portion of any other free writing prospectus relating to the offering containing material information about the undersigned Registrant or its securities provided by or on behalf of the undersigned Registrant; and

(iv)Any other communication that is an offer in the offering made by the undersigned Registrant to the purchaser.

II-4

Signatures

Pursuant to the requirements of the Securities Act of 1933, the Registrant certifies that it has reasonable grounds to believe that it meets all of the requirements for filing on Form S-3 and has duly caused this registration statement to be signed on its behalf by the undersigned, thereunto duly authorized, in the City of Burnaby, British Columbia, Canada on December 7, 2015.June 3, 2020.

Power ofOf Attorney

KNOW ALL PERSONS BY THESE PRESENTS, that each person whose signature appears below constitutes and appoints Simon Pimstone and Ian Mortimer as his or her true and lawful attorneys-in-fact and agents, with full power of substitution and resubstitution, for him or her and in his or her name, place and stead, in any and all capacities (including his or her capacity as a director and/or officer of Xenon Pharmaceuticals Inc.) to sign any and all amendments to this registration statement, on Form S-3,including post-effective amendments, and registration statements filed pursuant to Rule 462 under the Securities Act, and to file the same, with all exhibits thereto, and all other documents in connection therewith, with the Securities and Exchange Commission, granting unto said attorneys-in-fact and agents, and each of them, full power and authority to do and perform each and every act and thing requisite and necessary to be done in connection therewith, as fully to all intents and purposes as they, he or she might or could do in person, hereby ratifying and confirming all that said attorney-in-fact and agents or any of them, or their, his or her substitute or substitutes, may lawfully do or cause to be done by virtue hereof.

Pursuant to the requirements of the Securities Act of 1933, this registration statement has been signed by the following persons in the capacities and on the dates indicated.

II-5

Exhibit Index