X0306 4 2021-05-28 0 0001582313 Xenon Pharmaceuticals Inc. XENE 0001619962 ROBIN SHERRINGTON 200 - 3650 GILMORE WAY BURNABY A1 V5G 4W8 BRITISH COLUMBIA, CANADA 0 1 0 0 EVP, Strategy & Innovation Common Shares 2021-05-28 4 M 0 12345 3.76 A 29141 D Common Shares 2021-05-28 4 F 0 2024 18.91 D 27117 D Common Shares 2021-05-28 4 M 0 13374 3.85 A 40491 D Common Shares 2021-05-28 4 F 0 2192 18.91 D 38299 D Common Shares 2021-05-28 4 S 0 3155 18.81 D 35144 D Common Shares 2021-05-28 4 S 0 2912 18.81 D 32232 D Stock Option (Right to Buy) 3.76 2021-05-28 4 M 0 12345 0.00 D 2021-05-28 Common Shares 12345 0 D Stock Option (Right to Buy) 3.85 2021-05-28 4 M 0 13374 0.00 D 2021-05-28 Common Shares 13374 0 D The exercise price was converted from $3.74 CAD using the closing rate of exchange of the Bank of Canada on the date of grant. The actual exercise price is the Canadian dollar amount regardless of the exchange rate on the date of exercise. Represents the closing price of the Company's common shares on May 27, 2021, which was converted to a Canadian dollar amount for purposes of net settlement calculations. The "Amount" and "Price" reported in this Column 4 reflect the aggregate number and weighted-average price, respectively, of shares sold. These shares were sold in multiple transactions at prices ranging from $18.22 to $19.10, 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 25% of the shares subject to the Option vested on the one year anniversary of January 1, 2011 (the "January 2011 Vesting Commencement Date") and thereafter 1/48th of the shares subject to the Option vest on each monthly anniversary of the January 2011 Vesting Commencement Date. Expiration date differs from originally reported date due to an automatic extension provided by the option plan as a result of the original expiration date falling during a Company blackout period and a lock-up agreement period. 1/3 of the shares subject to the Option vested on March 12, 2011 (the "March 2011 Vesting Commencement Date") and thereafter the remaining 2/3 of the shares subject to the Option vest each monthly anniversary of the March 2011 Vesting Commencement Date over the following 4 years. /s/ Cassandra Robinson, Attorney-in-fact 2021-06-01