Xenon Pharmaceuticals Inc

We have a written code of conduct that applies to all of our directors, officers and employees. A copy of the most up-to-date version of our code of conduct is available within the “Investors” section on our company website located athttp://www.xenon-pharma.com and on SEDAR+ atwww.sedarplus.ca. We will post amendments to our code of conduct or waivers of the same for directors and executive officers on the “Investors” section on our website located athttps://www.xenon-pharma.com.

During the three months ended December 31, 2024, no director or officer, as defined in Rule 16a-1(f), adopted orterminated a "Rule 10b5-1 trading arrangement" or a "non-Rule 10b5-1 trading arrangement," each as defined in Item 408 of Regulation S-K.

Adoption of 2025 Inducement Plan

On February 27, 2025, the Board of Directors of the Company approved the 2025 Inducement Equity Incentive Plan (the "2025 Inducement Plan"). Pursuant to the terms of the 2025 Inducement Plan, the Company may grant nonstatutory stock options, stock appreciation rights, restricted stock units, restricted stock, and performance awards as an inducement material to individuals being hired, or rehired following a bona fide period of interruption of employment, as an employee of the Company or any of its subsidiaries. The Company has reserved 775,000 common shares for issuance under the 2025 Inducement Plan. In accordance with Nasdaq Listing Rule 5635(c)(4), the Company did not seek approval of the 2025 Inducement Plan by its shareholders.

The foregoing is a brief description of the material terms of the 2025 Inducement Plan and is qualified in its entirety by reference to the full text of the 2025 Inducement Plan filed as an exhibit to this Annual Report on Form 10-K.