144 0001880129 XXXXXXXX LIVE 0001582313 Xenon Pharmaceuticals Inc. 001-36687 3650 Gilmore Way Burnaby A1 V5G 4W8 (604)-484-3300 CHRISTOPHER JOHN KENNEY Officer Common Shares Morgan Stanley Wealth Management Canada Inc.

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2771 166559 83190316 03/10/2026 NASDAQ Common Shares 03/09/2026 Performance share unit award vesting Issuer N 7500 03/09/2026 N/A Y The Common Shares reported on this Form 144 were obtained via the vesting of a performance share unit award on March 9, 2026, and are being sold pursuant to a Rule 10b5-1 trading arrangement in the form of a durable sell-to-cover instruction. 03/10/2026 12/03/2025 /s/ Christopher Kenney