Recent Transactions and Developments	6 Months Ended
Sep. 30, 2026
Recent Transactions and Developments [Abstract]
Recent Transactions and Developments	Recent Transactions and Developments Global Settlement with Moderna On March 3, 2026, the Company’s subsidiary, Genevant Sciences GmbH (“Genevant”), Arbutus (together with Genevant, “Genevant/Arbutus”), and, solely for certain purposes, Genevant’s parent Genevant Sciences Ltd. (“GSL”), and Moderna, Inc. and ModernaTx, Inc. (together, “Moderna”) entered into a settlement agreement (the “Settlement Agreement”) to resolve all patent infringement litigation between Genevant/Arbutus and Moderna pending in the U.S. and internationally relating to Moderna’s unauthorized use of Genevant/Arbutus’ lipid nanoparticle (“LNP”) delivery technology in its vaccines, including its Covid-19 vaccine SPIKEVAX. Pursuant to the Settlement Agreement: •Moderna made a non-contingent, non-creditable, and non-refundable payment to Genevant and Arbutus of $950 million on July 8, 2026 (the “Fixed Payment”). •Moderna agreed to make up to an additional $1.3 billion contingent lump sum payment (the “Contingent Payment”) to Genevant and Arbutus if certain circumstances occur as more fully described below. •Moderna consented to entry of a judgment of infringement and of a judgment of no invalidity of four Genevant/Arbutus patents. •Genevant agreed to grant Moderna a global non-exclusive license to LNP delivery technology for infectious disease applications and a covenant not to sue for certain Genevant/Arbutus patents and Moderna products. Payments by Moderna under the Settlement Agreement are made directly to Genevant and Arbutus consistent with the terms of a cross-license agreement (as amended, the “Cross-License Agreement”) entered between Genevant (as assignee of GSL) and Arbutus. Pursuant to the Cross-License Agreement, Arbutus granted Genevant a license under certain patents and know-how relating to Arbutus’s LNP and GalNAc technologies for all applications other than hepatitis B virus and certain other excluded fields. As of September 30, 2026, RSL and Arbutus held 83% and 16%, respectively, of the issued and outstanding common shares of GSL. Under the terms of the Cross-License Agreement, payments made by Moderna pursuant to the Settlement Agreement to Genevant/Arbutus are allocated, after reimbursement of the parties’ respective litigation costs, (i) 80% to Genevant and (ii) 20% to Arbutus. Based on this allocation, Genevant received $771.6 million for its portion of the Fixed Payment on July 8, 2026. Included in Genevant’s portion of the Fixed Payment was approximately $1.0 million that Genevant remitted to Arbutus pursuant to a separate agreement. The Company recognized a gain on litigation settlement of $0.4 million for the six months ended September 30, 2026 in the accompanying condensed consolidated statements of operations as a result of the final determination of actual litigation costs incurred. In July 2026, GSL declared a dividend to GSL’s shareholders. Holders of equity awards granted under the GSL 2018 Equity Incentive Plan, as amended, with dividend equivalent rights also participated pro rata in the dividend (the dividend and dividend equivalent rights, together, the “Fixed Payment Distribution”). The portion of the Fixed Payment Distribution attributable to non-RSL common shareholders and other equity award holders was $186.6 million (including $67.3 million to Arbutus), of which $179.1 million was paid as of September 30, 2026. Additionally, as described in Note 7, “Certain Balance Sheet Components” as of September 30, 2026, accrued compensation-related expenses included $22.9 million for employee bonuses related to the global settlement reached with Moderna. Moderna will make the Contingent Payment to Genevant/Arbutus (i) if the U.S. Court of Appeals for the Federal Circuit (the “Federal Circuit”) (whether by the initial panel, upon panel rehearing or en banc) affirms, or if there is a final non-appealable judgment that affirms, the rejection of Moderna’s affirmative defense pursuant to 28 U.S.C. §1498 (“§ 1498”) by the U.S. District Court for the District of Delaware in its entirety or otherwise holds that § 1498 does not bar Genevant/Arbutus’ claim against Moderna as to either or both of direct infringement and indirect infringement with respect to all of the doses subject to Moderna’s appeal, or (ii) upon a voluntary dismissal of Moderna’s appeal (any of the foregoing under (i) or (ii), a “Genevant/Arbutus § 1498 Victory”). If the appellate court instead determines that § 1498 bars Genevant/Arbutus’ infringement claims as to some, but not all, of the doses subject to Moderna’s appeal, the Settlement Agreement provides that Moderna will pay Genevant/Arbutus a prorated amount of $1.3 billion, calculated based on the number of doses for which § 1498 bars Genevant/Arbutus’ infringement claims as clearly articulated by the Federal Circuit, or if not clearly articulated by the Federal Circuit, as mutually agreed by the parties or determined in an accelerated binding arbitration process. Under certain circumstances, if the Genevant/Arbutus § 1498 Victory is subsequently overturned in Moderna’s favor in a final nonappealable decision, Genevant/Arbutus is required to return the Contingent Payment to Moderna, plus interest. If, following a Genevant/Arbutus § 1498 Victory, either (i) Moderna does not timely appeal such Genevant/Arbutus § 1498 Victory or (ii) such Genevant/Arbutus § 1498 Victory is subsequently affirmed in a final nonappealable decision, Moderna will have no further right to a potential repayment of the Contingent Payment. The Contingent Payment is considered a gain contingency, and Genevant’s portion of such payment will be recognized when realized or realizable.

Recent Transactions and Developments

Global Settlement with Moderna

On March 3, 2026, the Company’s subsidiary, Genevant Sciences GmbH (“Genevant”), Arbutus (together with Genevant, “Genevant/Arbutus”), and, solely for certain purposes, Genevant’s parent Genevant Sciences Ltd. (“GSL”), and Moderna, Inc. and ModernaTx, Inc. (together, “Moderna”) entered into a settlement agreement (the “Settlement Agreement”) to resolve all patent infringement litigation between Genevant/Arbutus and Moderna pending in the U.S. and internationally relating to Moderna’s unauthorized use of Genevant/Arbutus’ lipid nanoparticle (“LNP”) delivery technology in its vaccines, including its Covid-19 vaccine SPIKEVAX.

Pursuant to the Settlement Agreement:

•Moderna made a non-contingent, non-creditable, and non-refundable payment to Genevant and Arbutus of $950 million on July 8, 2026 (the “Fixed Payment”).

•Moderna agreed to make up to an additional $1.3 billion contingent lump sum payment (the “Contingent Payment”) to Genevant and Arbutus if certain circumstances occur as more fully described below.

•Moderna consented to entry of a judgment of infringement and of a judgment of no invalidity of four Genevant/Arbutus patents.

•Genevant agreed to grant Moderna a global non-exclusive license to LNP delivery technology for infectious disease applications and a covenant not to sue for certain Genevant/Arbutus patents and Moderna products.

Payments by Moderna under the Settlement Agreement are made directly to Genevant and Arbutus consistent with the terms of a cross-license agreement (as amended, the “Cross-License Agreement”) entered between Genevant (as assignee of GSL) and Arbutus. Pursuant to the Cross-License Agreement, Arbutus granted Genevant a license under certain patents and know-how relating to Arbutus’s LNP and GalNAc technologies for all applications other than hepatitis B virus and certain other excluded fields. As of September 30, 2026, RSL and Arbutus held 83% and 16%, respectively, of the issued and outstanding common shares of GSL.

Under the terms of the Cross-License Agreement, payments made by Moderna pursuant to the Settlement Agreement to Genevant/Arbutus are allocated, after reimbursement of the parties’ respective litigation costs, (i) 80% to Genevant and (ii) 20% to Arbutus.

Based on this allocation, Genevant received $771.6 million for its portion of the Fixed Payment on July 8, 2026. Included in Genevant’s portion of the Fixed Payment was approximately $1.0 million that Genevant remitted to Arbutus pursuant to a separate agreement. The Company recognized a gain on litigation settlement of $0.4 million for the six months ended September 30, 2026 in the accompanying condensed consolidated statements of operations as a result of the final determination of actual litigation costs incurred.

In July 2026, GSL declared a dividend to GSL’s shareholders. Holders of equity awards granted under the GSL 2018 Equity Incentive Plan, as amended, with dividend equivalent rights also participated pro rata in the dividend (the dividend and dividend equivalent rights, together, the “Fixed Payment Distribution”). The portion of the Fixed Payment Distribution attributable to non-RSL common shareholders and other equity award holders was $186.6 million (including $67.3 million to Arbutus), of which $179.1 million was paid as of September 30, 2026.

Additionally, as described in Note 7, “Certain Balance Sheet Components” as of September 30, 2026, accrued compensation-related expenses included $22.9 million for employee bonuses related to the global settlement reached with Moderna.

Moderna will make the Contingent Payment to Genevant/Arbutus (i) if the U.S. Court of Appeals for the Federal Circuit (the “Federal Circuit”) (whether by the initial panel, upon panel rehearing or en banc) affirms, or if there is a final non-appealable judgment that affirms, the rejection of Moderna’s affirmative defense pursuant to 28 U.S.C. §1498 (“§ 1498”) by the U.S. District Court for the District of Delaware in its entirety or otherwise holds that § 1498 does not bar Genevant/Arbutus’ claim against Moderna as to either or both of direct infringement and indirect infringement with respect to all of the doses subject to Moderna’s appeal, or (ii) upon a voluntary dismissal of Moderna’s appeal (any of the foregoing under (i) or (ii), a “Genevant/Arbutus § 1498 Victory”). If the appellate court instead determines that § 1498 bars Genevant/Arbutus’ infringement claims as to some, but not all, of the doses subject to Moderna’s appeal, the Settlement Agreement provides that Moderna will pay Genevant/Arbutus a prorated amount of $1.3 billion, calculated based on the number of doses for which § 1498 bars Genevant/Arbutus’ infringement claims as clearly articulated by the Federal Circuit, or if not clearly articulated by the Federal Circuit, as mutually agreed by the parties or determined in an accelerated binding arbitration process.

Under certain circumstances, if the Genevant/Arbutus § 1498 Victory is subsequently overturned in Moderna’s favor in a final nonappealable decision, Genevant/Arbutus is required to return the Contingent Payment to Moderna, plus interest. If, following a Genevant/Arbutus § 1498 Victory, either (i) Moderna does not timely appeal such Genevant/Arbutus § 1498 Victory or (ii) such Genevant/Arbutus § 1498 Victory is subsequently affirmed in a final nonappealable decision, Moderna will have no further right to a potential repayment of the Contingent Payment.

The Contingent Payment is considered a gain contingency, and Genevant’s portion of such payment will be recognized when realized or realizable.