Nature of business and future operations	6 Months Ended
Jun. 30, 2026
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Nature of business and future operations	Nature of business and future operations Description of the Business Arbutus Biopharma Corporation (“Arbutus” or the “Company”) is a clinical-stage biopharmaceutical company focused on infectious disease. The Company is currently developing imdusiran (AB-729), its proprietary, GalNAc-conjugated, subcutaneously-delivered ribonucleic acid interference (RNAi) therapeutic, and AB-101, its proprietary oral PD-L1 inhibitor, for the treatment of chronic hepatitis B (“cHBV”). The Company continues to protect and defend its intellectual property, which is the subject of its ongoing lawsuits against Pfizer Inc., BioNTech SE, and certain of their affiliates (collectively, “Pfizer/BioNTech”) for their use of the Company’s patented lipid nanoparticle (“LNP”) technology in their COVID-19 messenger ribonucleic acid interference (mRNA)-LNP vaccines and any other products that would infringe the asserted patents. The court issued a claim construction ruling in September 2025, which construed the disputed claim terms in a manner the Company generally considers to be favorable. The parties are awaiting further scheduling in the litigation. In July 2026, the Company, along with its exclusive licensee Genevant Sciences GmbH, filed three international lawsuits seeking to enforce patents protecting the Company’s LNP technology against Pfizer/BioNTech. On March 3, 2026, the Company, along with Genevant Sciences GmbH and, solely for specified purposes, its parent company Genevant Sciences Ltd. (collectively, “Genevant,” a related party), entered into a settlement agreement (the “Moderna Settlement Agreement”) with Moderna, Inc. and ModernaTX, Inc. (together, “Moderna”) to resolve all patent infringement litigation and patent revocation proceedings involving Moderna and its affiliates pending in the United States and internationally (the “Moderna LNP Litigation”). Under the terms of the Moderna Settlement Agreement, Moderna made an aggregate $950.0 million noncontingent lump sum payment (the “Noncontingent Settlement Payment”) to the Company and Genevant on July 8, 2026. The Company received $178.4 million on July 8, 2026 as its share of the Noncontingent Settlement Payment, which included reimbursement of the Company’s litigation costs. In addition, Moderna is obligated to pay the Company and Genevant an additional aggregate contingent lump sum payment of $1.3 billion (the “Contingent Settlement Payment”) upon a ruling that is favorable to the Company and Genevant in a limited appeal related to 28 U.S.C. §1498 that Moderna filed, as allowed under the Moderna Settlement Agreement. The Company owned approximately 16% of the outstanding common equity of Genevant as of June 30, 2026, and the Company anticipates the payment of a material dividend from Genevant in the third quarter of calendar year 2026. Liquidity At June 30, 2026, the Company had an aggregate of $92.6 million in cash, cash equivalents and investments in marketable securities and no outstanding debt. The Company received $178.4 million as its share of the Noncontingent Settlement Payment on July 8, 2026. The Company believes it has sufficient cash resources to fund its operations for at least the next 12 months. The success of the Company’s operations is dependent on obtaining the necessary regulatory approvals to bring one or more of its product candidates to market and achieve profitability from ongoing operations. The Company’s development activities and the commercialization of its products are dependent on its ability to successfully complete these activities and to obtain adequate financing through a combination of financing activities and operations. It is not possible to predict either the outcome of the Company’s existing or future development programs or the Company’s ability to continue to fund these programs in the future.

Arbutus Biopharma Corporation (“Arbutus” or the “Company”) is a clinical-stage biopharmaceutical company focused on infectious disease. The Company is currently developing imdusiran (AB-729), its proprietary, GalNAc-conjugated, subcutaneously-delivered ribonucleic acid interference (RNAi) therapeutic, and AB-101, its proprietary oral PD-L1 inhibitor, for the treatment of chronic hepatitis B (“cHBV”).

The Company continues to protect and defend its intellectual property, which is the subject of its ongoing lawsuits against Pfizer Inc., BioNTech SE, and certain of their affiliates (collectively, “Pfizer/BioNTech”) for their use of the Company’s patented lipid nanoparticle (“LNP”) technology in their COVID-19 messenger ribonucleic acid interference (mRNA)-LNP vaccines and any other products that would infringe the asserted patents. The court issued a claim construction ruling in September 2025, which construed the disputed claim terms in a manner the Company generally considers to be favorable. The parties are awaiting further scheduling in the litigation. In July 2026, the Company, along with its exclusive licensee Genevant Sciences GmbH, filed three international lawsuits seeking to enforce patents protecting the Company’s LNP technology against Pfizer/BioNTech.

On March 3, 2026, the Company, along with Genevant Sciences GmbH and, solely for specified purposes, its parent company Genevant Sciences Ltd. (collectively, “Genevant,” a related party), entered into a settlement agreement (the “Moderna Settlement Agreement”) with Moderna, Inc. and ModernaTX, Inc. (together, “Moderna”) to resolve all patent infringement litigation and patent revocation proceedings involving Moderna and its affiliates pending in the United States and internationally (the “Moderna LNP Litigation”). Under the terms of the Moderna Settlement Agreement, Moderna made an aggregate $950.0 million noncontingent lump sum payment (the “Noncontingent Settlement Payment”) to the Company and Genevant on July 8, 2026. The Company received $178.4 million on July 8, 2026 as its share of the Noncontingent Settlement Payment, which included reimbursement of the Company’s litigation costs. In addition, Moderna is obligated to pay the Company and Genevant an additional aggregate contingent lump sum payment of $1.3 billion (the “Contingent Settlement Payment”) upon a ruling that is favorable to the Company and Genevant in a limited appeal related to 28 U.S.C. §1498 that Moderna filed, as allowed under the Moderna Settlement Agreement. The Company owned approximately 16% of the outstanding common equity of Genevant as of June 30, 2026, and the Company anticipates the payment of a material dividend from Genevant in the third quarter of calendar year 2026.

At June 30, 2026, the Company had an aggregate of $92.6 million in cash, cash equivalents and investments in marketable securities and no outstanding debt. The Company received $178.4 million as its share of the Noncontingent Settlement Payment on July 8, 2026. The Company believes it has sufficient cash resources to fund its operations for at least the next 12 months.