X0508 4 2026-01-02 false 0001582313 Xenon Pharmaceuticals Inc. XENE 0001619961 MORTIMER IAN 3650 GILMORE WAY BURNABY A1 V5G 4W8 BRITISH COLUMBIA, CANADA true true false false PRESIDENT & CEO true Common Shares 2026-01-02 4 M false 40000 7.49 A 46000 D Common Shares 2026-01-02 4 S false 37938 44.40 D 8062 D Common Shares 2026-01-02 4 S false 2062 44.93 D 6000 D Common Shares 14300 I By Spouse Stock Option (Right to Buy) 7.49 2026-01-02 4 M false 40000 0 D 2026-03-10 Common Shares 40000 0 D The sales reported in this Form 4 were effected pursuant to a Rule 10b5-1 trading plan adopted by the reporting person on September 27, 2024. The "Amount" and "Price" reported in this Column 4 reflect the aggregate number and weighted-average price (rounded to two decimal places), respectively, of shares sold. These share were sold in multiple transactions at prices ranging from $43.91 to $44.90, inclusive. The reporting person undertakes to provide to the issuer, any security holder of the issuer, or the SEC staff, upon request, full information regarding the number of shares sold at each separate price within the range set forth herein. The "Amount" and "Price" reported in this Column 4 reflect the aggregate number and weighted-average price (rounded to two decimal places), respectively, of shares sold. These share were sold in multiple transactions at prices ranging from $44.91 to $45.125, inclusive. The reporting person undertakes to provide to the issuer, any security holder of the issuer, or the SEC staff, upon request, full information regarding the number of shares sold at each separate price within the range set forth herein. The shares subject to the option are fully vested and exercisable. /s/ Nathaniel Adams, Attorney-in-fact 2026-01-02