144 0001619962 XXXXXXXX LIVE 0001582313 Xenon Pharmaceuticals Inc. 001-36687 200-3650 Gilmore Way Burnaby A1 V5G 4W8 (604)-484-3300 ROBIN SHERRINGTON Officer (non-Section 16) Common Shares Morgan Stanley Wealth Management Canada Inc.

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60000 2301600 75468883 06/12/2024 NASDAQ Stock Option 12/18/2015 Equity Incentive Grant Issuer N 15000 06/12/2024 See remarks Stock Option 03/11/2016 Equity Incentive Grant Issuer N 20000 06/12/2024 See remarks Stock Option 03/13/2017 Equity Incentive Grant Issuer N 27500 06/12/2024 See remarks Stock Option 10/23/2017 Equity Incentive Grant Issuer N 11000 06/12/2024 See remarks Y During the 90-day period following the filing of this Form 144, the reporting person anticipates selling up to 60,000 common shares resulting from the net exercise of the listed stock options. 06/12/2024 /s/ Robin Sherrington