X0202 SCHEDULE 13G/A 0000902664-19-001016 0001633313 XXXXXXXX LIVE 5 Common Shares, no par value per share 03/31/2026 0001582313 Xenon Pharmaceuticals, Inc. 98420N105 200 - 3650 GILMORE WAY BURNABY A1 00 Rule 13d-1(b) Avoro Capital Advisors LLC b DE 5777777.00 0.00 5777777.00 0.00 5777777.00 N 6.26 IA OO Behzad Aghazadeh b X1 5777777.00 0.00 5777777.00 0.00 5777777.00 N 6.26 HC IN Xenon Pharmaceuticals, Inc. 200-3650 Gilmore Way, Burnaby, British Columbia, Canada V5G 4W8 This statement is filed by: (i) Avoro Capital Advisors LLC, a Delaware limited liability company ("Avoro"), which provides investment advisory and management services and has acquired the common shares, no par value, (the "Common Shares") of Xenon Pharmaceuticals, Inc. (the "Company") solely for investment purposes on behalf of Avoro Life Sciences Fund LLC, a Delaware limited liability company, and (ii) Behzad Aghazadeh ("Dr. Aghazadeh," and together with Avoro, the "Reporting Persons"), who serves as the portfolio manager and controlling person of Avoro. The filing of this statement should not be construed as an admission that any Reporting Person is, for purposes of Section 13 of the Act, the beneficial owner of the securities reported herein. The address of the business office of each of the Reporting Persons is 110 Greene Street, Suite 800, New York, NY 10012. Avoro is a Delaware limited liability company. Dr. Aghazadeh is a United States citizen. N IA HC The information required by Item 4(a) is set forth in Row 9 of the cover page for each of the Reporting Persons and is incorporated herein by reference. The percentage set forth in this Schedule 13G is calculated based upon an aggregate of 92,247,633 Common Shares outstanding, as reported in the Company's Prospectus Supplement filed pursuant to Rule 424(b)(5) and the Company's Current Report on Form 8-K, each filed with the Securities and Exchange Commission on March 12, 2026, after giving effect to the completion of the offering and the exercise in full of the underwriters' overallotment option, as described therein. 6.26% The information required by Item 4(c)(i) is set forth in Row 5 of the cover page for each of the Reporting Persons and is incorporated herein by reference. The information required by Item 4(c)(ii) is set forth in Row 6 of the cover page for each of the Reporting Persons and is incorporated herein by reference. The information required by Item 4(c)(iii) is set forth in Row 7 of the cover page for each of the Reporting Persons and is incorporated herein by reference. The information required by Item 4(c)(iv) is set forth in Row 8 of the cover page for each of the Reporting Persons and is incorporated herein by reference. Y N See Item 2(a). Y Y Y N By signing below I certify that, to the best of my knowledge and belief, the securities referred to above were acquired and are held in the ordinary course of business and were not acquired and are not held for the purpose of or with the effect of changing or influencing the control of the issuer of the securities and were not acquired and are not held in connection with or as a participant in any transaction having that purpose or effect, other than activities solely in connection with a nomination under ?? 240.14a-11. Avoro Capital Advisors LLC /s/ Scott Epstein 05/15/2026 Behzad Aghazadeh /s/ Behzad Aghazadeh 05/15/2026