Arbutus Biopharma Corp

Previous wording

You should read the following discussion and analysis by our management of our financial position and results of operations in conjunction with our audited consolidated financial statements and related notes thereto included as part of our Annual Report on Form 10-K for the year ended December 31, 2025 and our unaudited condensed consolidated financial statements for the three and six months ended June 30, 2026. Our consolidated financial statements have been prepared in accordance with United States generally accepted accounting principles and are presented in U.S. dollars.

Current wording

You should read the following discussion and analysis by our management of our financial position and results of operations in conjunction with our audited consolidated financial statements and related notes thereto included as part of our Annual Report on Form 10-K for the year ended December 31, 2025 and our unaudited condensed consolidated financial statements for the three and nine months ended September 30, 2026. Our consolidated financial statements have been prepared in accordance with United States generally accepted accounting principles and are presented in U.S. dollars.

Previous wording

as well as other statements relating to our future operations, financial performance or financial condition, prospects or other future events. Forward-looking statements appear primarily in the sections of this Form 10-Q entitled “Part I, Item 1-Financial

Current wording

as well as other statements relating to our future operations, financial performance or financial condition, prospects or other future events. Forward-looking statements appear primarily in the sections of this Form 10-Q entitled “Part I, Item 1-Financial Statements (Unaudited),” and “Part I, Item 2-Management’s Discussion and Analysis of Financial Condition and Results of Operations.”

Previous wording

We continue to protect and defend our intellectual property, which is the subject of our ongoing lawsuits against Pfizer Inc., BioNTech SE, and certain of their affiliates (collectively, Pfizer/BioNTech) for their use of our 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 we generally consider to be favorable. The parties are awaiting further scheduling in the litigation. In July 2026, we, along with our exclusive licensee Genevant Sciences GmbH, filed three international lawsuits seeking to enforce patents protecting our LNP technology against Pfizer/BioNTech.

Current wording

We continue to protect and defend our intellectual property, which is the subject of our ongoing lawsuits against Pfizer Inc., BioNTech SE, and certain of their affiliates (collectively, Pfizer/BioNTech) for their use of our 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 U.S. District Court for the District of New Jersey issued a claim construction ruling in September 2025, which construed the disputed claim terms in a manner we generally consider to be favorable. Fact discovery is ongoing and a final pretrial conference is scheduled for November 2027. The parties are awaiting a trial date in the litigation. In July 2026 and November 2026, we, along with our exclusive licensee Genevant Sciences GmbH, filed multiple international lawsuits seeking to enforce patents protecting our LNP technology against Pfizer/BioNTech.

Previous wording

On March 3, 2026, we, 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 us and Genevant on July 8, 2026. We received $178.4 million on July 8, 2026 as our share of the Noncontingent Settlement Payment, which included reimbursement of our litigation costs. 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 filed, as allowed under the Moderna Settlement Agreement (the Moderna §1498 Appeal). 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. We are currently evaluating a return of capital to our shareholders in the third quarter of calendar year 2026.

Current wording

In March 2026, we, 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 us and Genevant in July 2026. We received $178.4 million in July 2026 as our share of the Noncontingent Settlement Payment, which included reimbursement of our litigation costs. 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 filed, as allowed under the Moderna Settlement Agreement (the Moderna §1498 Appeal). On November 5, 2026, expedited oral argument was held at the U.S. Court of Appeals for the Federal Circuit regarding the Moderna §1498 Appeal, and a decision is forthcoming. We owned approximately 16% of the outstanding common equity of Genevant as of September 30, 2026, and we received a cash dividend of $67.3 million from Genevant in September 2026, which represented a distribution of Genevant’s earnings in connection with the Noncontingent Settlement Payment.

Previous wording

•Imdusiran (AB-729) is our proprietary, GalNAc-conjugated, subcutaneously-delivered RNAi therapeutic product candidate that suppresses all HBV antigens, including HBsAg, which is thought to be a key prerequisite to enable potentiation of a patient’s immune system to respond to HBV. Over 200 patients with cHBV infection have been dosed with imdusiran in Phase 1 and Phase 2a clinical trials. Clinical data generated thus far has shown imdusiran provides meaningful reductions in HBsAg and other viral proteins, HBV DNA and HBV RNA, and leads to functional cure in some patients, while being generally safe and well-tolerated. Benefits were observed in patients across all evaluated HBV genotypes (A to E). In the Phase 1 and Phase 2a clinical trials, eight patients achieved functional cure, off all treatment, in combination therapy that includes imdusiran, including two patients who did not receive any pegylated interferon alfa-2a (IFN) as part of the combination therapy. An additional 41 patients across our Phase 2a clinical trials were able to remain off nucleos(t)ide analogue (NA) therapy for at least 48 weeks after discontinuing NA therapy during their Phase 2a clinical trials. A total of 47% (49/105) of all Phase 2a patients achieved functional cure or remained off NA therapy after discontinuing NA therapy during their Phase 2a clinical trials. Of the 18 patients who are currently being followed long-term (which includes the eight functionally cured patients described above and 10 patients who discontinued and remained off NA therapy), one patient who discontinued NA therapy achieved functional cure during the long-term follow-up period, and 89% of the 18 patients continue to remain off NA therapy for between 93 and 146 weeks. Two of the original eight functionally cured patients seroreverted during long-term follow-up, but remain virally suppressed and off NA therapy. Furthermore, among an additional 11 patients with available data who discontinued NA therapy during their Phase 2a clinical trials, but were subsequently discontinued early from long-term follow-up, one patient achieved functional cure and two restarted NA therapy. To date, a total of 10 patients have achieved functional cure during our Phase 2a clinical trials and long-term follow-up.

Current wording

•Imdusiran (AB-729) is our proprietary, GalNAc-conjugated, subcutaneously-delivered RNAi therapeutic product candidate that suppresses all HBV antigens, including HBsAg, which is thought to be a key prerequisite to enable potentiation of a patient’s immune system to respond to HBV. Over 200 patients with cHBV infection have been dosed with imdusiran in Phase 1 and Phase 2a clinical trials. Clinical data generated thus far has shown imdusiran provides meaningful reductions in HBsAg and other viral proteins, HBV DNA and HBV RNA, and leads to functional cure in some patients, while being generally safe and well-tolerated. Benefits were observed in patients across all evaluated HBV genotypes (A to E). In the Phase 1 and Phase 2a clinical trials, eight patients achieved functional cure, off all treatment, in combination therapy that includes imdusiran, including two patients who did not receive any pegylated interferon alfa-2a (IFN) as part of the combination therapy. An additional 41 patients across our Phase 2a clinical trials were able to remain off nucleos(t)ide analogue (NA) therapy for at least 48 weeks after discontinuing NA therapy during their Phase 2a clinical trials. A total of 47% (49/105) of all Phase 2a patients achieved functional cure or remained off NA therapy after discontinuing NA therapy during their Phase 2a clinical trials. Of the 18 patients who are currently being followed long-term (which includes the eight functionally cured patients described above and 10 patients who discontinued and remained off NA therapy), one patient who discontinued NA therapy achieved functional cure during the long-term follow-up period, and 89% of the 18 patients continue to remain off NA therapy for between 106 and 146 weeks. Three of the original eight functionally cured patients seroreverted during long-term follow-up, but remain virally suppressed and off NA therapy. Furthermore, among an additional 11 patients with available data who discontinued NA therapy during their Phase 2a clinical trials, but were subsequently discontinued early from long-term follow-up, one patient achieved functional cure and two restarted NA therapy. To date, a total of 10 patients have achieved functional cure during our Phase 2a clinical trials and long-term follow-up.

Previous wording

To date, six of those eight patients continue to sustain functional cure for periods ranging between 93 to 146 weeks, while two patients have seroreverted but remain virally suppressed and off NA therapy. In addition to the patients who achieved functional cure during their Phase 2a clinical trials, 41 more patients were able to remain off NA therapy for at least 48 weeks during their clinical trials after discontinuing NA therapy following treatment with imdusiran. In total, 47% (49/105) of all Phase 2a patients either achieved functional cure or remained off NA therapy after discontinuing NA therapy during their clinical trials following treatment with imdusiran. Of the 10 patients who were able to discontinue and remain off NA therapy for at least 48 weeks who are currently being followed long-term in our rollover study, one patient achieved functional cure during the long-term follow-up period, and a total of eight patients have continued to remain off NA therapy for periods ranging between 93 to 146 weeks. These results suggest that imdusiran has lasting durability in helping patients maintain viral suppression and may help patients achieve beneficial clinical outcomes years after completing finite imdusiran regimens.

Current wording

In the Phase 2a clinical trials, eight patients with cHBV achieved functional cure following treatment with imdusiran and NA therapy in combination with either IFN or with low dose nivolumab plus an immunotherapeutic. Seven of those eight total patients who achieved functional cure with the 60mg dose of imdusiran had HBsAg levels less than 1000 IU/mL at baseline. According to the literature, patients with HBsAg levels <1000 IU/mL represent a significant portion of the cHBV population. To date, five of those eight patients continue to sustain functional cure for periods ranging between 106 to 146 weeks, while three patients have seroreverted but remain virally suppressed and off NA therapy. In addition to the patients who achieved functional cure during their Phase 2a clinical trials, 41 more patients were able to remain off NA therapy for at least 48 weeks during their clinical trials after discontinuing NA therapy following treatment with imdusiran. In total, 47% (49/105) of all Phase 2a patients either achieved functional cure or remained off NA therapy after discontinuing NA therapy during their clinical trials following treatment with imdusiran. Of the 10 patients who were able to discontinue and remain off NA therapy for at least 48 weeks who are currently being followed long-term in our rollover study, one patient achieved functional cure during the long-term follow-up period, and a total of eight patients have continued to remain off NA therapy for periods ranging between 131 to 146 weeks. These results suggest that imdusiran has lasting durability in helping patients maintain viral suppression and may help patients achieve beneficial clinical outcomes years after completing finite imdusiran regimens.

Previous wording

Alnylam’s ONPATTRO, which represents the first approved application of our LNP technology, was approved by the FDA and the European Medicines Agency (EMA) during the third quarter of 2018 and was launched by Alnylam immediately upon approval in the United States. Under the terms of this license agreement, we are entitled to tiered royalty payments on global net sales of ONPATTRO ranging from 1.00% - 2.33% after offsets, with the highest tier applicable to annual net sales above $500 million. This royalty interest was sold to the Ontario Municipal Employees Retirement System (OMERS), effective as of January 1, 2019, for $20 million in gross proceeds before advisory fees. OMERS will retain this entitlement until it has received $30 million in royalties, at which point 100% of this royalty entitlement on future global net sales of ONPATTRO will revert to us. OMERS has assumed the risk of collecting up to $30 million of future royalty payments from Alnylam and we are not obligated to reimburse OMERS if it fails to collect any such future royalties. If this royalty entitlement reverts to us, it has the potential to provide an active royalty stream or to be otherwise monetized again in full or in part. From the inception of the royalty sale through June 30, 2026, an aggregate of $26.9 million of royalties have been earned by OMERS.

Current wording

Alnylam’s ONPATTRO, which represents the first approved application of our LNP technology, was approved by the FDA and the European Medicines Agency (EMA) during the third quarter of 2018 and was launched by Alnylam immediately upon approval in the United States. Under the terms of this license agreement, we are entitled to tiered royalty payments on global net sales of ONPATTRO ranging from 1.00% - 2.33% after offsets, with the highest tier applicable to annual net sales above $500 million. This royalty interest was sold to the Ontario Municipal Employees Retirement System (OMERS), effective as of January 1, 2019, for $20 million in gross proceeds before advisory fees. OMERS will retain this entitlement until it has received $30 million in royalties, at which point 100% of this royalty entitlement on future global net sales of ONPATTRO will revert to us. OMERS has assumed the risk of collecting up to $30 million of future royalty payments from Alnylam and we are not obligated to reimburse OMERS if it fails to collect any such future royalties. If this royalty entitlement reverts to us, it has the potential to provide an active royalty stream or to be otherwise monetized again in full or in part. From the inception of the royalty sale through September 30, 2026, an aggregate of $27.0 million of royalties have been earned by OMERS.

Previous wording

Additionally, if Genevant receives proceeds from an action for infringement by any third parties of our intellectual property licensed to Genevant, we would be entitled to receive, after deduction of litigation costs, 20% of the proceeds received by

Current wording

Additionally, if Genevant receives proceeds from an action for infringement by any third parties of our intellectual property licensed to Genevant, we would be entitled to receive, after deduction of litigation costs, 20% of the proceeds received by Genevant or, if less, tiered low single-digit royalties on net sales of the infringing product (inclusive of the proceeds from litigation or settlement, which would be treated as net sales).

Previous wording

Under the terms of the Moderna Settlement Agreement, Moderna made an aggregate $950.0 million Noncontingent Settlement Payment to us and Genevant on July 8, 2026. We received $178.4 million on July 8, 2026 as our share of the Noncontingent Settlement Payment, which included reimbursement of our litigation costs. In addition, Moderna is obligated to make an additional Contingent Settlement Payment of up to an aggregate $1.3 billion to us and Genevant upon the occurrence of certain events related to the Moderna §1498 Appeal, but which may be subject to repayment. The Company anticipates the payment of a material dividend from Genevant in the third quarter of calendar year 2026.

Current wording

Under the terms of the Moderna Settlement Agreement, Moderna made an aggregate $950.0 million Noncontingent Settlement Payment to us and Genevant in July 2026. We received $178.4 million in July 2026 as our share of the Noncontingent Settlement Payment, which included reimbursement of our litigation costs. In addition, Moderna is obligated to make an additional Contingent Settlement Payment of up to an aggregate $1.3 billion to us and Genevant upon the occurrence of certain events related to the Moderna §1498 Appeal, but which may be subject to repayment.

Previous wording

In March 2025, we and Genevant entered into an agreement (the RSV Agreement) that provided that we would be entitled to any award of damages in, or proceeds from the settlement of, our patent litigation against Moderna that was specifically allocated to infringing acts related to Moderna’s vaccine for respiratory syncytial virus (mRESVIA) and, in the event there was no such specific allocation to mRESVIA, we and Genevant would discuss an appropriate allocation in good faith. The Moderna Settlement Agreement did not specifically allocate any settlement proceeds to infringing acts related to mRESVIA. On July 15, 2026, we and Genevant entered into an agreement to terminate the RSV Agreement (the RSV Termination Agreement). Pursuant to the RSV Termination Agreement, we received a termination fee of $1.0 million from Genevant on July 21, 2026, and all rights or obligations under the RSV Agreement were terminated.

Current wording

In March 2025, we and Genevant entered into an agreement (the RSV Agreement) that provided that we would be entitled to any award of damages in, or proceeds from the settlement of, our patent litigation against Moderna that was specifically allocated to infringing acts related to Moderna’s vaccine for respiratory syncytial virus (mRESVIA) and, in the event there was no such specific allocation to mRESVIA, we and Genevant would discuss an appropriate allocation in good faith. The Moderna Settlement Agreement did not specifically allocate any settlement proceeds to infringing acts related to mRESVIA. In July 2026, we and Genevant entered into an agreement to terminate the RSV Agreement (the RSV Termination Agreement). Pursuant to the RSV Termination Agreement, we received a termination fee of $1.0 million from Genevant in July 2026, and all rights or obligations under the RSV Agreement were terminated.

Previous wording

On April 4, 2023, we and Genevant filed a lawsuit in the United States District Court for the District of New Jersey against Pfizer/BioNTech seeking damages for infringement of United States Patent Nos. 9,504,651; 8,492,359; 11,141,378; 11,298,320; and 11,318,098 in the manufacture and sale of any COVID-19 mRNA-LNP vaccines. The patents relate to nucleic acid-lipid particles and their composition, manufacture, delivery and methods of use. In the lawsuit, we seek fair compensation for Pfizer’s and BioNTech’s use of our patented technology that was developed with great effort and at great expense, without which their COVID-19 mRNA-LNP vaccines would not have been successful. The claim construction hearing occurred in December 2024, and in September 2025, the court issued a claim construction ruling, which construed the disputed claim terms in a manner we generally consider to be favorable. The parties are awaiting further scheduling in the litigation.

Current wording

In April 2023, we and Genevant filed a lawsuit in the United States District Court for the District of New Jersey against Pfizer/BioNTech seeking damages for infringement of United States Patent Nos. 9,504,651; 8,492,359; 11,141,378; 11,298,320; and 11,318,098 in the manufacture and sale of any COVID-19 mRNA-LNP vaccines. The patents relate to nucleic acid-lipid particles and their composition, manufacture, delivery and methods of use. In the lawsuit, we seek fair compensation for Pfizer’s and BioNTech’s use of our patented technology that was developed with great effort and at great expense, without which their COVID-19 mRNA-LNP vaccines would not have been successful. The claim construction hearing occurred in December 2024, and in September 2025, the court issued a claim construction ruling, which construed the disputed claim terms in a manner we generally consider to be favorable. Fact discovery is ongoing and a final pretrial conference is scheduled for November 2027. The parties are awaiting a trial date in the litigation.

Previous wording

In July 2026, we, along with Genevant, filed three international lawsuits seeking to enforce patents protecting our LNP technology against Pfizer/BioNTech and certain of their affiliates. We and Genevant are seeking monetary relief, as well as injunctions against Pfizer/BioNTech’s COVID-19 mRNA-LNP vaccines and any other products that would infringe the asserted patents.

Current wording

In July 2026 and November 2026, we, along with Genevant, filed multiple international lawsuits seeking to enforce patents protecting our LNP technology against Pfizer/BioNTech and certain of their affiliates. We and Genevant are seeking monetary relief, as well as injunctions against Pfizer/BioNTech’s COVID-19 mRNA-LNP vaccines and any other products that would infringe the asserted patents.

Previous wording

The three international lawsuits are as follows:

Current wording

The international lawsuits are as follows:

Previous wording

•Canada: Federal Court of Canada File No. T-3200-26, seeking a permanent injunction and damages or, if Arbutus and Genevant elect, an accounting of Pfizer/BioNTech’s profits, attributable to infringement of Canadian Patent No. 2,721,333

Current wording

•Canada: Federal Court of Canada File No. T-3200-26, seeking a permanent injunction and damages or, if Arbutus and Genevant elect, an accounting of Pfizer/BioNTech’s profits, attributable to infringement of Canadian Patent Nos. 2,721,333 and 2,767,127

Previous wording

On February 28, 2022, we and Genevant filed a lawsuit in the United States District Court for the District of Delaware against Moderna seeking damages for infringement of United States Patent Nos. 8,058,069, 8,492,359, 8,822,668, 9,364,435, 9,504,651, and 11,141,378 in the manufacture and sale of MRNA-1273, Moderna’s vaccine for COVID-19. On March 3, 2025, we and Genevant filed five international lawsuits against Moderna seeking to enforce patents protecting our patented LNP technology. Together, these lawsuits comprise the Moderna LNP Litigation.

Current wording

In February 2022, we and Genevant filed a lawsuit in the United States District Court for the District of Delaware against Moderna seeking damages for infringement of United States Patent Nos. 8,058,069, 8,492,359, 8,822,668, 9,364,435, 9,504,651, and 11,141,378 in the manufacture and sale of MRNA-1273, Moderna’s vaccine for COVID-19. In March 2025, we and Genevant filed five international lawsuits against Moderna seeking to enforce patents protecting our patented LNP technology. Together, these lawsuits comprise the Moderna LNP Litigation.

Previous wording

On March 3, 2026, we and Genevant entered into the Moderna Settlement Agreement with Moderna to resolve the Moderna LNP Litigation. Pursuant to the Moderna Settlement Agreement, all parties filed stipulated judgments and stipulations of dismissal for the respective courts or tribunals to enter judgment, dismiss with prejudice or withdraw (as the case may be) all claims in the Moderna LNP Litigation, except that Moderna was allowed to file the Moderna §1498 Appeal. The Moderna §1498 Appeal is an appeal of the consent judgment entered in the District Court solely with respect to whether §1498 bars our and Genevant’s claims for direct infringement and indirect infringement against Moderna for vaccine doses that were sold to the United States Government under a particular contract and characterized by the District Court as “vaccines that did not go directly to United States Government employees.”

Current wording

In March 2026, we and Genevant entered into the Moderna Settlement Agreement with Moderna to resolve the Moderna LNP Litigation. Pursuant to the Moderna Settlement Agreement, all parties filed stipulated judgments and stipulations of dismissal for the respective courts or tribunals to enter judgment, dismiss with prejudice or withdraw (as the case may be) all claims in the Moderna LNP Litigation, except that Moderna was allowed to file the Moderna §1498 Appeal. The Moderna §1498 Appeal is an appeal of the consent judgment entered in the District Court solely with respect to whether §1498 bars our and Genevant’s claims for direct infringement and indirect infringement against Moderna for vaccine doses that were sold to the United States Government under a particular contract and characterized by the District Court as “vaccines that did not go directly to United States Government employees.” On November 5, 2026, expedited oral argument was held at the U.S. Court of Appeals for the Federal Circuit regarding the Moderna §1498 Appeal, and a decision is forthcoming.

Previous wording

In addition, as described in more detail in, and subject to the terms of, the Moderna Settlement Agreement, Moderna will make an additional Contingent Settlement Payment of an aggregate $1.3 billion to us and Genevant (i) if the Court of Appeals for the Federal Circuit (whether by the initial panel, upon panel rehearing oren banc) affirms, or if there is a final non-appealable judgment that affirms, the rejection of Moderna’s affirmative defense pursuant to §1498 by the District Court in its entirety or otherwise holds that §1498 does not bar our and Genevant’s claim against Moderna as to either or both of direct infringement and indirect infringement with respect to all of the doses subject to the Moderna §1498 Appeal, or (ii) upon a voluntary dismissal of the Moderna §1498 Appeal (any of the foregoing (clause (i) or (ii) above), an Arbutus/Genevant §1498 Victory). If an appellate ruling were to hold that §1498 bars our and Genevant’s infringement claims as to some, but not all, of the doses subject to the Moderna §1498 Appeal, the Moderna Settlement Agreement provides that Moderna will pay us and Genevant a prorated amount of the Contingent Settlement Payment, calculated based on the number of doses for which §1498 bars our and Genevant’s 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.

Current wording

In addition, as described in more detail in, and subject to the terms of, the Moderna Settlement Agreement, Moderna will make an additional Contingent Settlement Payment of an aggregate $1.3 billion to us and Genevant (i) if the U.S. Court of Appeals for the Federal Circuit (whether by the initial panel, upon panel rehearing oren banc) affirms, or if there is a final non-appealable judgment that affirms, the rejection of Moderna’s affirmative defense pursuant to §1498 by the District Court in its entirety or otherwise holds that §1498 does not bar our and Genevant’s claim against Moderna as to either or both of direct infringement and indirect infringement with respect to all of the doses subject to the Moderna §1498 Appeal, or (ii) upon a voluntary dismissal of the Moderna §1498 Appeal (any of the foregoing (clause (i) or (ii) above), an Arbutus/Genevant §1498 Victory). If an appellate ruling were to hold that §1498 bars our and Genevant’s infringement claims as to some, but not all, of the doses subject to the Moderna §1498 Appeal, the Moderna Settlement Agreement provides that Moderna will pay us and Genevant a prorated amount of the Contingent Settlement Payment, calculated based on the number of doses for which §1498 bars our and Genevant’s 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.

Previous wording

On March 19, 2026, we and Genevant filed a complaint against the United States in the United States Court of Federal Claims, seeking to recover compensation for Moderna’s infringement for vaccine doses that were sold to the United States Government under a particular contract and were deemed by the District Court to be doses that were provided directly to United States Government employees. The complaint also includes a protective request to recover compensation from the United States for any other vaccine doses where, as a result of the Moderna §1498 Appeal, §1498 is deemed to bar our and Genevant’s claims for direct infringement and indirect infringement against Moderna.

Current wording

In March 2026, we and Genevant filed a complaint against the United States in the United States Court of Federal Claims, seeking to recover compensation for Moderna’s infringement for vaccine doses that were sold to the United States Government under a particular contract and were deemed by the District Court to be doses that were provided directly to United States Government employees. The complaint also includes a protective request to recover compensation from the United States for any other vaccine doses where, as a result of the Moderna §1498 Appeal, §1498 is deemed to bar our and Genevant’s claims for direct infringement and indirect infringement against Moderna.

Previous wording

On April 5, 2018, Moderna and Merck, Sharp & Dohme Corporation (together with its successors and affiliates, Merck) filed Notices of Opposition to our European patent EP 2279254 (the ’254 Patent) with the European Patent Office (EPO), requesting that the ’254 Patent be revoked in its entirety for all contracting states. From 2018 until 2024, various hearings were held by different divisions of the EPO regarding requests submitted by all parties. Oral proceedings were held in June 2024, and the Opposition Division of the EPO upheld the ’254 Patent but declined our and Genevant’s request to broaden certain claims in the ’254 Patent. Both parties appealed the Opposition Division’s decision, and on January 15, 2026, in a verbal decision, the Board of Appeal of the EPO revoked the ’254 Patent. We are awaiting a written decision from the Board of Appeal of the EPO regarding the revocation. We disagree with the outcome, and upon receipt of the written decision, we plan to file a petition for review by the Enlarged Board of Appeal of the EPO. The revocation was based on an EPO standard of “added matter” that does not apply in the United States. In March 2026, pursuant to the Moderna Settlement Agreement, Moderna withdrew from this revocation proceeding. In May 2026, we entered into an agreement with Merck (the Merck Agreement) where we, among other things, acknowledged that the Moderna Settlement Agreement covered a vaccine being jointly developed by Moderna and Merck and we agreed not to sue Merck regarding such vaccine, in exchange for Merck withdrawing from the revocation proceeding. On May 6, 2026, Merck withdrew from this revocation proceeding. We do not expect the EPO revocation decision to have an impact on the potential outcome, or timing, of our patent infringement litigation pending against Pfizer/BioNTech.

Current wording

In April 2018, Moderna and Merck, Sharp & Dohme Corporation (together with its successors and affiliates, Merck) filed Notices of Opposition to our European patent EP 2279254 (the ’254 Patent) with the European Patent Office (EPO), requesting that the ’254 Patent be revoked in its entirety for all contracting states. From 2018 until 2024, various hearings were held by different divisions of the EPO regarding requests submitted by all parties. Oral proceedings were held in June 2024, and the Opposition Division of the EPO upheld the ’254 Patent but declined our and Genevant’s request to broaden certain claims in the ’254 Patent. Both parties appealed the Opposition Division’s decision, and in June 2026, the Board of Appeal of the EPO issued a written decision explaining their earlier verbal revocation of the ’254 Patent. We disagree with the outcome, and we filed a petition for review by the Enlarged Board of Appeal of the EPO in August 2026. A hearing has been scheduled for March 2027. We do not expect the EPO revocation decision to have an impact on the potential outcome, or timing, of our patent infringement litigation pending against Pfizer/BioNTech.

Previous wording

On April 29, 2025, Moderna filed a revocation action on our European patent EP 4241767 (the ’767 patent) with the EPO, requesting that the patent be revoked in its entirety for all contracting states. In July 2025, Merck, Arrowhouse GmbH and Keltie LLP filed three additional revocation actions against the ’767 patent. Initial briefing has been completed and we are currently awaiting an initial hearing date. In March 2026, pursuant to the Moderna Settlement Agreement, Moderna withdrew from this revocation proceeding. On May 6, 2026, pursuant to the Merck Agreement, Merck withdrew from this revocation proceeding.

Current wording

In April 2025, Moderna filed a revocation action on our European patent EP 4241767 (the ’767 patent) with the EPO, requesting that the patent be revoked in its entirety for all contracting states. In July 2025, Merck, Arrowhouse GmbH and Keltie LLP filed three additional revocation actions against the ’767 patent. Initial briefing has been completed and we are currently awaiting an initial hearing date. In March 2026, pursuant to the Moderna Settlement Agreement, Moderna withdrew from this revocation proceeding. In May 2026, we entered into an agreement with Merck (the Merck Agreement) where we, among other things, acknowledged that the Moderna Settlement Agreement covered a vaccine being jointly developed by Moderna and Merck and we agreed not to sue Merck regarding such vaccine, in exchange for Merck withdrawing from the revocation proceeding. In May 2026, pursuant to the Merck Agreement, Merck withdrew from this revocation proceeding.

Previous wording

Total revenue increased $167.6 million for the six months ended June 30, 2026 compared to the same period in 2025, primarily due to recognizing revenue of $178.4 million for our share of the Noncontingent Settlement Payment in 2026, partially offset by recognizing all $9.6 million of previously deferred revenue upon the conclusion of our strategic partnership with Qilu in 2025.

Current wording

Total revenue increased $167.4 million for the nine months ended September 30, 2026 compared to the same period in 2025, primarily due to recognizing revenue of $178.4 million for our share of the Noncontingent Settlement Payment in 2026, partially offset by recognizing all $9.6 million of previously deferred revenue upon the conclusion of our strategic partnership with Qilu in 2025.

Previous wording

Research and development expenses decreased $2.6 million and $7.4 million for the three and six months ended June 30, 2026, respectively, compared to the same periods in 2025. The decreases were due primarily to cost savings from our decisions to reduce our workforce and discontinue in-house scientific research, as well as lower clinical trial costs as studies neared completion.

Current wording

Research and development expenses decreased $3.2 million and $10.6 million for the three and nine months ended September 30, 2026, respectively, compared to the same periods in 2025. The decreases were due primarily to cost savings from our decisions to reduce our workforce and discontinue in-house scientific research, as well as lower clinical trial costs as studies neared completion.

Previous wording

General and administrative expenses increased $0.5 million for each of the three and six months ended June 30, 2026 as compared to the same periods in 2025, due primarily to an increase in litigation-related legal fees driven by the settlement with Moderna, partially offset by cost-cutting efforts by the Company, which drove reductions in employee compensation-related expenses.

Current wording

General and administrative expenses increased $4.9 million and $5.5 million for the three and nine months ended September 30, 2026, respectively, as compared to the same periods in 2025, due primarily to higher employee compensation-related expenses driven by the one-time cash bonuses paid to our executives in consideration of the significant efforts and accomplishments associated with the Moderna Settlement Agreement.

Previous wording

As of June 30, 2026, there was an aggregate of $0.2 million of accrued restructuring costs for medical benefits and lease-related operating expenses included in accounts payable and accrued liabilities.

Current wording

As of September 30, 2026, there was an aggregate of $0.1 million of accrued restructuring costs for medical benefits and lease-related operating expenses included in accounts payable and accrued liabilities.

Previous wording

The decrease in interest income for the three and six months ended June 30, 2026 compared to the same periods in 2025 was due primarily to less interest earned on our cash and investment balances due to a lower average balance and a general decrease in market interest rates.

Current wording

The increase in interest income for the three and nine months ended September 30, 2026 compared to the same periods in 2025 was due primarily to higher interest earned on our cash and investment balances due to a higher average balance.

Previous wording

Interest expense for the three and six months ended June 30, 2026 and 2025 consisted primarily of non-cash amortization of discount and issuance costs related to the sale of a portion of our ONPATTRO royalty interest to OMERS in July 2019. The decrease is related to the declining balance of the unamortized discount and issuance costs.

Current wording

Interest expense for the three and nine months ended September 30, 2026 and 2025 consisted primarily of non-cash amortization of discount and issuance costs related to the sale of a portion of our ONPATTRO royalty interest to OMERS in July 2019. The decrease is related to the declining balance of the unamortized discount and issuance costs.

Previous wording

For the six months ended June 30, 2026, $14.1 million of cash was used in operating activities compared to $29.1 million used in operating activities for the six months ended June 30, 2025, a decrease of $15.0 million. The decrease was due primarily to our decisions to decrease our workforce and further streamline the organization to focus our efforts on advancing the clinical development of imdusiran and AB-101.

Current wording

For the nine months ended September 30, 2026, $225.7 million of cash was provided by operating activities compared to $35.0 million used in operating activities for the nine months ended September 30, 2025, an increase of $260.6 million. The increase was due primarily to the receipt of $178.4 million on July 8, 2026 as our share of the Noncontingent Settlement Payment related to the Moderna Settlement Agreement, which included reimbursement of our litigation costs, the cash dividend of $67.3 million received from Genevant on September 22, 2026, which represented a distribution of Genevant’s earnings in connection with the Noncontingent Settlement Payment, and our decisions to decrease our workforce and further streamline the organization to focus our efforts on advancing the clinical development of imdusiran and AB-101.

Previous wording

For the six months ended June 30, 2026, net cash provided by investing activities was $0.5 million, resulting primarily from maturities of investments in marketable securities of $38.0 million, partially offset by additional investments in marketable securities of $37.5 million. For the six months ended June 30, 2025, net cash provided by investing activities was $27.0 million, which resulted primarily from maturities of investments in marketable securities of $90.2 million, partially offset by additional investments in marketable securities of $63.2 million.

Current wording

For the nine months ended September 30, 2026, net cash provided by investing activities was $1.0 million, resulting primarily from maturities of investments in marketable securities of $68.0 million, partially offset by additional investments in marketable securities of $67.0 million. For the nine months ended September 30, 2025, net cash provided by investing activities was $16.9 million, which resulted primarily from maturities of investments in marketable securities of $131.4 million, partially offset by additional investments in marketable securities of $114.5 million.

Previous wording

For the six months ended June 30, 2026, net cash provided by financing activities was $14.8 million, which was primarily related to $14.7 million in proceeds from the issuance of common shares pursuant to the exercise of stock options. For the six months ended June 30, 2025, net cash provided by financing activities was $3.2 million, which included $3.1 million in proceeds from the issuance of common shares pursuant to the exercise of stock options.

Current wording

For the nine months ended September 30, 2026, net cash provided by financing activities was $19.5 million, which was primarily related to $19.3 million in proceeds from the issuance of common shares pursuant to the exercise of stock options. For the nine months ended September 30, 2025, net cash provided by financing activities was $4.1 million, which included $3.9 million in proceeds from the issuance of common shares pursuant to the exercise of stock options.

Previous wording

As of June 30, 2026, we had cash, cash equivalents and investments in marketable securities of $92.6 million. We had no outstanding debt as of June 30, 2026.

Current wording

As of September 30, 2026, we had cash, cash equivalents and investments in marketable securities of $337.5 million. We had no outstanding debt as of September 30, 2026. On October 1, 2026, subsequent to the quarter ended September 30, 2026, we accepted for purchase a total of 46 million of our common shares for an aggregate purchase price of $230 million, which was funded with available cash and settled on October 5, 2026.

Previous wording

We have a royalty entitlement on ONPATTRO, a drug developed by Alnylam that incorporates our LNP technology and was approved by the FDA and the EMA during the third quarter of 2018 and was launched by Alnylam immediately upon approval in the United States. In July 2019, we sold a portion of this royalty interest to OMERS, effective as of January 1, 2019, for $20 million in gross proceeds before advisory fees. OMERS will retain this entitlement until it has received $30 million in royalties, at which point 100% of such royalty interest on future global net sales of ONPATTRO will revert to us. OMERS has assumed the risk of collecting up to $30 million of future royalty payments from Alnylam and we are not obligated to reimburse OMERS if it fails to collect any such future royalties. From the inception of the royalty sale through June 30, 2026, we have recorded an aggregate of $26.9 million of non-cash royalty revenue for royalties earned by OMERS. If this royalty entitlement reverts to us, it has the potential to provide an active royalty stream or to be otherwise monetized again in full or in part. In addition to the royalty from the Alnylam LNP license agreement, we are also receiving a second, lower royalty interest on global net sales of ONPATTRO originating from a settlement agreement and subsequent license agreement with Acuitas. The royalty from Acuitas has been retained by us and was not part of the royalty sale to OMERS. In addition, we are entitled to receive payments upon the achievement of contractual milestones related to Alnylam’s use of our proprietary LNP technology in other product candidates.

Current wording

We have a royalty entitlement on ONPATTRO, a drug developed by Alnylam that incorporates our LNP technology and was approved by the FDA and the EMA during the third quarter of 2018 and was launched by Alnylam immediately upon approval in the United States. In July 2019, we sold a portion of this royalty interest to OMERS, effective as of January 1, 2019, for $20 million in gross proceeds before advisory fees. OMERS will retain this entitlement until it has received $30 million in royalties, at which point 100% of such royalty interest on future global net sales of ONPATTRO will revert to us. OMERS has assumed the risk of collecting up to $30 million of future royalty payments from Alnylam and we are not obligated to reimburse OMERS if it fails to collect any such future royalties. From the inception of the royalty sale through September 30, 2026, we have recorded an aggregate of $27.0 million of non-cash royalty revenue for royalties earned by OMERS. If this royalty entitlement reverts to us, it has the potential to provide an active royalty stream or to be otherwise monetized again in full or in part. In addition to the royalty from the Alnylam LNP license agreement, we are also receiving a second, lower royalty interest on global net sales of ONPATTRO originating from a settlement agreement and subsequent license agreement with Acuitas. The royalty from Acuitas has been retained by us and was not part of the royalty sale to OMERS. In addition, we are entitled to receive payments upon the achievement of contractual milestones related to Alnylam’s use of our proprietary LNP technology in other product candidates.