Business Description

Overview Arbutus Biopharma Corporation (“Arbutus”, the “Company”, “we”, “us”, and “our”) is a clinical-stage biopharmaceutical company focused on infectious disease. We are currently developing imdusiran (AB-729), our proprietary, GalNAc-conjugated, subcutaneously-delivered ribonucleic acid interference (RNAi) therapeutic, and AB-101, our proprietary oral PD-L1 inhibitor, for the treatment of chronic hepatitis B (cHBV). We continue to protect and defend our intellectual property, which is the subject of our ongoing lawsuit against Pfizer Inc. and BioNTech SE (collectively, Pfizer/BioNTech) for their use of our patented lipid nanoparticle (LNP) technology in their COVID-19 messenger ribonucleic acid interference (mRNA)-LNP vaccines. The court issued a claim construction ruling in September 2025, which construed the disputed claim terms in a manner we generally consider to be favorable. The parties are awaiting further scheduling in the litigation. On March 3, 2026, we, along with Genevant Sciences GmbH and its parent (collectively, Genevant), entered into a settlement agreement (the Moderna Settlement Agreement) to resolve all patent infringement litigation and patent revocation proceedings involving Moderna, Inc. and its affiliates (collectively, Moderna) pending in the United States and internationally (the Moderna LNP Litigation). Under the terms of the Moderna Settlement Agreement, Moderna will make an aggregate $950.0 million noncontingent lump sum payment (the Noncontingent Settlement Payment) to us and Genevant on or before July 8, 2026. In addition, Moderna is obligated to pay us and Genevant an additional aggregate contingent lump sum payment of $1.3 billion (the Contingent Settlement Payment) upon a ruling that is favorable to us and Genevant in a limited appeal related to 28 U.S.C. §1498 (§1498) that Moderna is allowed to file pursuant to the Moderna Settlement Agreement (the Moderna §1498 Appeal). Under our license with Genevant, we are entitled to receive, after deduction of litigation costs, 20% of the Noncontingent Settlement Payment. In addition, as of the date of this annual report, we own approximately 16% of the outstanding common equity of Genevant. We are currently evaluating a return of capital to our shareholders in the third quarter of calendar year 2026, following the receipt of our portion of the Noncontingent Settlement Payment. For more information, see “Item 1 – Business – Other Collaborations, Royalty Entitlements and Intellectual Property Litigation” and “Item 3 – Legal Proceedings.” During 2024, we streamlined the organization to focus our efforts on advancing the clinical development of imdusiran and AB-101, and therefore ceased all discovery efforts, halted preparations for a potential IM-PROVE III clinical trial and reduced our workforce by 40%. In the first quarter of 2025, we announced the appointment of five new members of our Board of Directors (our Board) to replace all of the former directors, as well as the appointment of a new President, Chief Executive Officer and Chairperson of our Board and a new Chief Financial Officer. Additionally, our Board took action to reduce our workforce by an additional 57%. Our Board also decided to exit our corporate headquarters in Warminster, Pennsylvania and to discontinue in-house scientific research. In connection with these actions, we incurred one-time restructuring charges during 2025 of $12.9 million. With these organizational changes and our ongoing cost management efforts, we significantly reduced our net cash burn in 2025 when compared to 2024. In June 2025, we launched a new Scientific Advisory Board (SAB) consisting of globally-recognized leaders in the treatment of cHBV with extensive experience in late-stage clinical trials. SAB members are advising us on the strategic evaluation of our cHBV pipeline. In August 2025, we announced changes to our Board. Effective August 4, 2025, Anuj Hasija resigned from our Board due to his transition to a full-time executive role at another company that precludes his participation on our Board and other boards of directors. Dr. Roger Sawhney was appointed to the vacant seat on our Board, effective August 4, 2025. Dr. Sawhney was also appointed as a member of our Board’s Audit Committee and Corporate Governance and Nominating Committee.…