The Board of Directors of Arbutus Biopharma (the "Company") sets high standards for the Company's employees, officers and directors. Implicit in this philosophy is the importance of sound corporate governance. It is the duty of the Board of Directors to serve as a prudent fiduciary for shareholders and to oversee the management of the Company's business. To fulfill its responsibilities and to discharge its duty, the Board of Directors follows the procedures and standards that are set forth in these guidelines. These guidelines are subject to modification from time to time as the Board of Directors deems appropriate in the best interests of the Company or as required by applicable laws and regulations.

Summary of Amendments to Code of Business Conduct

On September 25, 2025, the Board of Directors (the “Board”) of Arbutus Biopharma Corporation (the “Company”) amended and restated the Company’s Code of Business Conduct (the “Amended Code”). In an effort to streamline the Company’s corporate policies, the Amended Code has primarily been updated to integrate terms from the Company’s now terminated Anti-Fraud Compliance Policy, Anti-Corruption Compliance Policy and Export Control and Sanctions Policy. Additional changes include directing Board members to refer to the Company’s Corporate Governance Guidelines, requiring the Company to post the Amended Code on its website and identify that location in its annual proxy statement, clarifying when the Amended Code governs when in conflict with the law or local custom/policy, adding process details in the event of a corporate opportunity that may conflict with a duty of loyalty to the Company or other conflicts of interest, and providing guidelines for representing the Company in a public setting or online, including social media. The Amended Code was effective upon adoption by the Board and did not result in any waiver, explicit or implicit, of any provision of the Company’s previous Code of Business Conduct. The above summary of the Amended Code is qualified in its entirety by reference to the full text of the Amended Code, which is available on the Company’s website at www.arbutusbio.com under the “Investors – Corporate Governance” section.