Risk Factors Dashboard

Once a year, publicly traded companies issue a comprehensive report of their business, called a 10-K. A component mandated in the 10-K is the ‘Risk Factors’ section, where companies disclose any major potential risks that they may face. This dashboard highlights all major changes and additions in new 10K reports, allowing investors to quickly identify new potential risks and opportunities.

View risk factors by ticker

Search filings by term

Risk Factors - ABUS

-New additions in green
-Changes in blue
-Hover to see similar sentence in last filing

Item 1A. Risk Factors” in this Annual Report on Form 10-K for the year ended December 31, 2025.

Risks Related to Our Business, Our Financial Results and Need for Additional Capital

•We are involved in patent infringement lawsuits to protect and assert our intellectual property rights against large, well-capitalized companies and the United States, which requires that we continue to expend substantial resources, and we may not be successful in these proceedings.

•We face risks associated with the Contingent Settlement Payment (defined below) under the Moderna Settlement Agreement (defined below).

•We are in the early stages of our development, and there is a limited amount of information about us upon which you can evaluate our product candidates.

• Additional funds may be dilutive to shareholders or impose operational restrictions.

• To date, we have had no product revenues.

•We do not generate revenues from product sales and may never be profitable from operations.

Risks Related to Development, Clinical Testing, Regulatory Approval, Marketing, and Coverage and Reimbursement of our Product Candidates

•Our product candidates are in early stages of development and must go through clinical trials, which are very expensive, time-consuming and difficult to design and implement.

•Preclinical studies and preliminary and interim data from clinical trials of our product candidates are not necessarily predictive of the results or success of ongoing or later clinical trials of our product candidates.

•Because we have limited operational resources, we may decide to pursue a particular product candidate and fail to advance product candidates that later demonstrate a greater chance of clinical and commercial success.

•

•We cannot guarantee how long it will take regulatory agencies to review our applications for product candidates.

•Disruptions at the FDA, including due to a reduction in the FDA’s workforce and/or inadequate funding for the FDA, could prevent the FDA from performing normal functions on which our business relies, which could negatively impact our business.

•If a particular product candidate causes undesirable side effects, then we may be unable to receive regulatory approval of or commercialize such product candidate.

•We may find it difficult to enroll patients in our clinical trials, which could hinder such clinical trials.

•It may take considerable time and expense to resolve the clinical hold that has been placed on our IND application of AB-101 by the FDA, and no assurance can be given that the FDA will remove the clinical hold, in which case our business and financial prospects may be adversely affected.

•Even if our product candidates obtain regulatory approval, they will remain subject to ongoing regulatory requirements.

•We face significant competition from other biotechnology and pharmaceutical companies targeting HBV (defined below).

•Our ability to generate product revenues and become profitable from operations is largely dependent on the future commercial success of our HBV product candidates.

•We may incur substantial liabilities and may be required to limit commercialization of our products in response to product liability lawsuits.

•Coverage and adequate reimbursement may not be available for our product candidates, which could make it difficult for us to sell our products profitably.

•We are subject to United States and Canadian healthcare laws and regulations, which could expose us to criminal sanctions, civil penalties, contractual damages and reputational harm.

•If we participate in the Medicaid Drug Rebate Program and other governmental pricing programs, failure to comply with obligations under these programs could result in additional reimbursement requirements, penalties, sanctions and fines, which could have a material adverse effect on our business, financial condition, results of operations and growth prospects.

•Failure to comply with the United States Foreign Corrupt Practices Act, and potentially other global anti-corruption and anti-bribery laws, could subject us to penalties and other adverse consequences.

Risks Related to Our Dependence on Third Parties

•We depend on our license agreement with Alnylam Pharmaceuticals, Inc. for the commercialization of ONPATTRO™ (Patisiran).

•We expect to depend in part on our licensing agreements for a significant portion of our revenues for the foreseeable future and to develop, conduct clinical trials with, obtain regulatory approvals for, and manufacture, market and sell some of our product candidates. If these licensing agreements are unsuccessful, or anticipated milestone or royalty payments are not received, our business could be materially adversely affected.

•

•We rely on third parties to conduct our clinical trials, and if they fail to fulfill their obligations, our development plans may be adversely affected.

•We rely exclusively on third parties to formulate and manufacture our product candidates, which exposes us to a number of risks that may delay development, regulatory approval and commercialization of our products.

Risks Related to Our Intellectual Property

•Other entities may assert patent rights that prevent us from developing or commercializing our products.

•Certain of our patents and patent applications have been challenged and found to be invalid, and additional challenges may occur in the future, which could adversely affect our business.

•We have incurred, and may in the future continue to incur, substantial costs as a result of litigation or other proceedings relating to patent and other intellectual property rights, and we may not be successful in one or more of these lawsuits or proceedings, any of which could have a material adverse effect on our business, financial condition and results of operations and could cause the market value of our common shares to decline.

•Confidentiality agreements with employees and others, including collaborators, may not adequately prevent disclosure of trade secrets and other proprietary information.

Risks Related to the Ownership of our Common Shares

•The concentration of common share ownership will likely limit the ability of the other shareholders to influence corporate matters.

•We are incorporated in Canada, with our assets located both in Canada and the United States, with the result that it may be difficult for investors to enforce judgments obtained against us or some of our officers.

•If we are deemed to be a “passive foreign investment company” for the current or any future taxable year, investors who are subject to United States federal taxation would likely suffer materially adverse United States federal income tax consequences.

•

General Risk Factors

•We could face liability from our controlled use of hazardous and radioactive materials.

•Our business, reputation, and operations could suffer in the event of information technology system failures.

•We may form strategic alliances or collaborations that could harm our business.

PART I

Item 1. Business

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.

Strategy

Our strategy is focused on maximizing opportunities for our cHBV development programs and, through our exclusive license with Genevant, our in-house developed LNP technology.

LNP technology

In February 2022 and April 2023, we filed patent infringement lawsuits in the United States against Moderna and Pfizer/BioNTech, respectively, seeking compensation for their unlicensed use of our patented technologies in their COVID-19 mRNA-LNP vaccines. It is well established in the scientific literature that the most significant technological hurdle to developing and deploying medicines using mRNA is engineering a safe and effective way to deliver the mRNA to human cells. Scientists at Arbutus and Genevant have spent years developing and refining LNP technology, which has been licensed for various applications to many different third parties. Our and Genevant’s LNP technology relies on microscopic particles built from four carefully selected types of fat-like molecules to shelter and protect nucleic acid molecules, including ribonucleic acid (RNA) molecules like the messenger RNA (mRNA) utilized in COVID-19 mRNA-LNP vaccines. This technology enables the mRNA to travel through the human body to a target cell and through the target cell’s membrane, where it releases the mRNA. Without this crucial technology, the mRNA would quickly degrade in the body and be ineffective. We continue to protect and defend our intellectual property, which is the subject of our ongoing lawsuit against Pfizer/BioNTech for their use of our patented LNP technology in their COVID-19 mRNA-LNP vaccines.

cHBV programs

Our hepatitis B (HBV) strategy has been to develop a functional cure for patients with cHBV infection with imdusiran as a potential cornerstone in a combination therapy. Development to date has emphasized a combination of compounds that can suppress hepatitis B virus deoxyribonucleic acid (HBV DNA) replication, hepatitis B virus RNA (HBV RNA) transcription, and hepatitis B surface antigen (HBsAg) and other viral protein expression, as well as boost patients’ HBV-specific immune response, which together could address the most important elements to achieving a functional cure. Functional cure is defined as sustained HBsAg seroclearance and HBV DNA less than the lower limit of quantification (<LLOQ) after 24 weeks off treatment, with or without anti-hepatitis B surface antibodies (anti-HBs). A functional cure for patients with cHBV could prevent complications of HBV disease progression, decrease HBV burden by minimizing patient stigma and address the need for finite and more efficacious HBV treatments that further improve long-term outcomes and reduce associated healthcare costs. Our current ongoing evaluation of our HBV strategy also includes analysis of imdusiran’s potential to suppress HBV DNA replication and HBV RNA and HBsAg expression, without any immunotherapeutics. We are also continuing to evaluate and refine potential Phase 2b clinical trial designs for imdusiran.

Our HBV product pipeline includes the following:

•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 82 and 134 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.

•AB-101 is our proprietary oral PD-L1 inhibitor that has the potential to activate patients’ HBV-specific immune response by inhibiting PD-L1. AB-101 is currently in a Phase 1a/1b clinical trial (AB-101-001) evaluating the safety, tolerability, pharmacokinetics (PK), and pharmacodynamics (PD) of single- and multiple-ascending oral doses in healthy subjects and patients with cHBV infection. The data from healthy subjects in Parts 1 and 2 and cHBV patients in Part 3 of this clinical trial have shown that AB-101 was generally well-tolerated with evidence of high receptor occupancy.

To help position imdusiran as a potential cornerstone in a combination therapy, we fully enrolled two Phase 2a clinical trials that combined imdusiran with other agents. The intent of these trials was to initially lower HBsAg levels with imdusiran and then administer a complementary agent, an immune modulator or a therapeutic vaccine, to further lower HBsAg levels and promote anti-HBV immunity. We believe that if we can lower HBsAg and other viral antigens and promote immunity, we may achieve sustained HBsAg seroclearance and HBV DNA <LLOQ, potentially leading to a functional cure in patients with cHBV. Currently, patients with cHBV have limited treatment options - either NA therapy, which requires lifelong treatment, or a finite duration of IFN, which is poorly tolerated and has serious complications and side effects. We believe patients can see significant benefits with imdusiran even without functional cure if they are well enough to be able to discontinue NA therapy and maintain viral suppression.

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, six of those eight patients continue to sustain functional cure for periods ranging between 82 to 134 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 96 to 131 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.

Our imdusiran development program includes the following two Phase 2a clinical trials:

•Imdusiran in combination with IFN, an approved immunomodulator, and ongoing standard-of-care NA therapy in patients with cHBV infection (IM-PROVE I). At the American Association for the Study of Liver Diseases (AASLD) – The Liver Meeting® in November 2024, we presented data from our IM-PROVE I Phase 2a clinical trial showing that six doses of imdusiran and 24 weeks of IFN added to ongoing NA therapy led to a functional cure rate of 50% (3/6) in hepatitis B e antigen (HBeAg) negative patients with baseline HBsAg levels less than 1000 IU/mL, and an overall functional cure rate of 25% (3/12). Additionally, three cHBV patients from other cohorts in the IM-PROVE I clinical trial achieved functional cure. Those patients who achieved functional cure also seroconverted. Furthermore, an additional 10 patients who did not achieve functional cure were able to remain off NA therapy for at least 48 weeks after discontinuing NA therapy following treatment with imdusiran. At the AASLD – The Liver Meeting in November 2025, we presented new analysis from our IM-PROVE I Phase 2a clinical trial showing beneficial clinical outcomes were observed across all evaluated HBV genotypes (A to D), even in genotypes described in literature as not responsive to IFN treatment. These data from the IM-PROVE I trial suggest that the combination of imdusiran, 24 weeks of IFN and NA therapy was generally safe and well-tolerated with beneficial clinical outcomes, and that imdusiran may enhance responsiveness to IFN in HBV genotypes that are poor responders to IFN.

•Imdusiran in combination with VTP-300, Barinthus Biotherapeutics plc’s (Barinthus) HBV immunotherapeutic, and ongoing NA therapy in patients with cHBV infection, including a cohort with the addition of low dose nivolumab (Opdivo®) (IM-PROVE II). At the European Association for the Study of the Liver (EASL) Congress in May 2025, we presented data from this clinical trial showing that 25% (2/8) of the patients with low dose nivolumab added to the treatment regimen and with baseline HBsAg levels less than 1000 IU/mL achieved functional cure. Furthermore, an additional 31 patients (including some HBeAg positive patients) who did not achieve functional cure were able to

remain off NA therapy for at least 48 weeks after discontinuing NA therapy following treatment with imdusiran. These data from the IM-PROVE II trial suggest that the combination of imdusiran, VTP-300, NA therapy and low dose nivolumab was generally safe and well-tolerated with beneficial clinical outcomes.

Background on HBV

Hepatitis B is a potentially life-threatening liver infection caused by HBV. We believe there is a compelling market opportunity for an HBV curative regimen.

Current treatments and their limitations

Today’s current treatment options for cHBV infection include IFN and NA therapies. NA therapies are oral antiviral medications which, when taken chronically, reduce HBV virus replication and inflammation and significantly reduce HBV DNA in the blood.

Our Product Candidates

Our pipeline consists of two product candidates that are designed to suppress HBV DNA and HBV RNA, reduce HBsAg and other viral antigens and/or boost HBV-specific immune responses, to allow cHBV patients to become and remain treatment-free, as follows:

We continue to explore pipeline opportunities in the form of potential strategic alliances, in order to accelerate the development of these programs.

RNAi therapeutic (imdusiran, AB-729)

RNAi therapeutics represent a significant advancement in drug development. We are developing an RNAi therapeutic, imdusiran, that is designed to reduce HBV DNA, HBV RNA, HBsAg and other HBV antigen expression in people with cHBV infection. Reducing HBsAg in addition to other viral proteins and HBV DNA are widely believed to be key prerequisites to potentiate an effective patient’s immune response against the virus.

Imdusiran has the following advantages over other RNAi therapeutics in development for cHBV infection:

–Targeted to hepatocytes using our proprietary covalently conjugated GalNAc delivery technology which provides highly efficient liver-targeted uptake and enables subcutaneous dosing.

–Unique nucleotide sequence that is single trigger and targets all HBV transcripts including HBx from cccDNA and integrated HBV DNA.

–Specific chemical modifications and unique asymmetric RNA structure that reduces off-target effects while maintaining/enhancing potency and providing durable liver exposure and in vivo therapeutic effect.

–Delivered at a low dose and infrequently (4, 8 or 12 week intervals).

–Immune activation properties with HBV-specific T-cell immune restoration and a decrease in exhausted T-cells in responder patients.

IM-PROVE I Phase 2a proof-of-concept clinical trial evaluating imdusiran in combination with IFN

We have completed IM-PROVE I, a randomized, open label, multicenter Phase 2a proof-of-concept clinical trial investigating the safety and antiviral activity of imdusiran in combination with a short course of IFN and ongoing NA therapy in 43 stably NA-suppressed, HBeAg negative, non-cirrhotic patients with cHBV infection. Our primary intent for this trial was to initially

lower HBsAg and other viral proteins, HBV DNA and HBV RNA levels with imdusiran and then administer IFN as an immunomodulator to promote anti-HBV immune responses. Our belief in this trial was that if we can lower HBsAg, other viral proteins and HBV DNA levels and promote immune responses, we may achieve sustained HBsAg seroclearance and HBV DNA <LLOQ, potentially leading to a functional cure. After patients received 24-weeks of dosing with imdusiran (60mg every 8 weeks, 4 doses) plus ongoing NA therapy, patients were randomized into one of four cohorts to receive a short course of IFN plus ongoing NA therapy for either 12 or 24 weeks, with or without up to two additional doses of imdusiran across an additional 16 week period. After completion of the assigned IFN treatment period, all patients remained on NA therapy for a 24-week follow-up period, and then discontinued NA treatment, provided they met protocol-defined NA therapy discontinuation criteria.

Select key data from 12 patients in Cohort A1 of this Phase 2a clinical trial who received 6 doses of imdusiran, 24 weeks of IFN and ongoing NA therapy, as presented at the AASLD – The Liver Meeting in November 2024, include:

•50% (3/6) of patients with baseline HBsAg <1000 IU/mL achieved functional cure.

•Overall, 25% (3/12) of patients achieved functional cure.

•Those patients who achieved functional cure also seroconverted with anti-HBs levels increasing as patients lost HBsAg.

At the EASL Congress in May 2025, we presented a poster characterizing the demographics and virological markers of the six cHBV patients across dosing cohorts in the IM-PROVE I Phase 2a clinical trial who achieved functional cure. The data showed that HBsAg at baseline was the only apparent marker in common associated with functional cure. In a second poster, we reported that patients who achieved functional cure in the 24-week IFN treatment cohorts experienced HBsAg seroclearance associated with transient HBV RNA elevations that were preceded by or coincided with increases in immunological markers. At the AASLD – The Liver Meeting in November 2025, we presented new analysis from our IM-PROVE I Phase 2a clinical trial showing beneficial clinical outcomes were observed across all evaluated HBV genotypes (A to D).

Additionally, a total of 10 patients in IM-PROVE I who did not achieve functional cure were still able to remain off NA therapy for at least 48 weeks after discontinuing NA therapy following treatment with imdusiran. Across all cohorts and all baseline HBsAg levels, 37% (16/43) of patients either achieved functional cure or remained off NA therapy for at least 48 weeks after discontinuing NA therapy following treatment with imdusiran at 60mg.

These data from the IM-PROVE I trial suggest that the combination of imdusiran and IFN was generally safe and well-tolerated. There were no serious adverse events related to imdusiran, IFN or NA therapy, and no adverse events leading to discontinuation. The most common imdusiran-related treatment emergent adverse events (TEAEs) were injection site bruising and transient alanine aminotransferase elevations, which occurred in association with decreasing HBsAg levels and/or markers of immune activation, and which returned to baseline values in all instances. The IFN-related TEAEs were consistent with the known safety profile of IFN.

IM-PROVE II Phase 2a proof-of-concept clinical trial evaluating imdusiran in combination with Barinthus’ VTP-300

Through a clinical collaboration agreement with Barinthus that we entered into in July 2021, we completed IM-PROVE II, a Phase 2a proof-of-concept clinical trial evaluating the safety, antiviral activity and immunogenicity of a combination treatment with Barinthus’ VTP-300, an HBV immunotherapeutic, administered after imdusiran in patients with cHBV infection. Our primary intent for this trial was to initially lower HBsAg and other viral proteins, HBV DNA and HBV RNA levels with imdusiran and then administer VTP-300 as an immunomodulator to promote anti-HBV immune responses. All patients received imdusiran (60mg every 8 weeks, 4 doses) plus NA therapy for 24 weeks. After week 24, treatment with imdusiran was stopped. Patients continued only on NA therapy and were randomized to receive VTP-300 or placebo at week 26 and week 30. At week 48, all patients were evaluated for eligibility to discontinue NA therapy and were followed for an additional 24 to 48 weeks. Subsequently, we amended the IM-PROVE II clinical trial protocol to include another cohort that received imdusiran, VTP-300, NA therapy and low dose nivolumab, an approved PD-1 inhibitor in oncology. In this additional cohort, patients received imdusiran (60mg every 8 weeks, 4 doses) plus NA therapy for 24 weeks, followed by administration of VTP-300 plus up to two low doses of nivolumab while remaining on NA therapy.

The cohort that included low dose nivolumab was the best performing cohort in the IM-PROVE II clinical trial. At the AASLD – The Liver Meeting in November 2024, we presented data from this clinical trial showing that the addition of low dose nivolumab increased rates of HBsAg seroclearance in cHBV patients and that 23% (3/13) of patients who received the treatment regimen with low dose nivolumab achieved HBsAg seroclearance by week 48. At the EASL Congress in May 2025, we presented data showing that 25% (2/8) of patients with low dose nivolumab added to the treatment regimen and with baseline HBsAg<1000 IU/mL achieved functional cure.

Additionally, a total of 31 patients in IM-PROVE II who did not achieve functional cure were still able to remain off NA therapy for at least 48 weeks after discontinuing NA therapy following treatment with imdusiran at 60mg. A total of 53% (33/62) of patients either achieved functional cure or remained off NA therapy for at least 48 weeks after discontinuing NA therapy following treatment with imdusiran at 60mg, across all cohorts and all baseline HBsAg levels, and both HBeAg negative and positive patients. Treatment with imdusiran, VTP-300, NA therapy and low dose nivolumab in this clinical trial was generally safe and well-tolerated. There were no serious adverse events, immune-related adverse events, or discontinuations due to adverse events.

However, in January 2025, Barinthus announced a shift in its strategic business focus that included postponing further development of VTP-300. The parties do not intend to undertake a larger Phase 2b with this combination treatment regimen.

At the AASLD - The Liver Meeting in November 2025, we presented cumulative data across all of our imdusiran clinical trials demonstrating that imdusiran was safe and well-tolerated at all tested repeat doses of 60mg or 90mg, and that beneficial clinical outcomes in our Phase 2a clinical trials were potentially linked to immune reawakening in patients.

Imdusiran Treatment Without Immunotherapeutic

In our single and multiple ascending dose Phase 1b clinical trial for imdusiran, we enrolled HBeAg negative and positive patients, as well as HBV DNA positive patients not on NA therapy. Across all arms, which included doses up to 180mg, 71% (44/62) of patients achieved HBsAg levels below 100 IU/mL, including 5% (3/62) of patients who achieved HBsAg seroclearance. Additionally, 56% (5/9) of patients who elected to discontinue NA therapy remained off NA therapy for at least three years after discontinuation. Furthermore, all patients in all imdusiran clinical trials showed significant early decreases in HBsAg levels, often observed after the first or second dose of imdusiran. In Group B of IM-PROVE II, after just 24 weeks of imdusiran dosing at just 60 mg with only background NA therapy and no other combination agent, 37% (7/19) of patients were able to remain off NA therapy for at least 48 weeks after discontinuing NA therapy, including one patient who achieved HBsAg seroclearance. Based on the effect imdusiran alone appears to have on reducing HBsAg levels and suppressing HBV DNA and HBV RNA replication, we are also evaluating imdusiran as a treatment without any immunotherapeutic.

Oral PD-L1 Inhibitor (AB-101)

PD-L1 inhibitors complement our pipeline of agents and could potentially be an important part of a combination therapy for the treatment of HBV by activating the immune system.

AB-101 is our proprietary oral small-molecule PD-L1 inhibitor candidate that we believe will allow for controlled checkpoint blockade while minimizing the systemic safety issues often seen with checkpoint inhibitor antibody therapies. AB-101 is differentiated from monoclonal antibody checkpoint inhibitors such as durvalumab (anti-PD-L1) and nivolumab (anti-PD-1) because it is liver centric, has a much shorter duration of effect in preclinical models (which may provide dosing and safety advantages), and has a novel mechanism of action as it binds to PD-L1 on the surface of cells causing dimerization, internalization and degradation of the PD-L1 protein.

Phase 1a/1b clinical trial to evaluate safety, tolerability and PK/PD of AB-101 (AB-101-001)

AB-101-001 is a Phase 1a/1b clinical trial designed to investigate the safety, tolerability and PK/PD of single and multiple-ascending oral doses of AB-101 for up to 28 days in healthy subjects and patients with cHBV infection. The trial consists of three parts starting with single ascending doses in healthy subjects, followed by multiple ascending doses in healthy subjects and culminating with multiple doses in patients with cHBV infection. Safety and PK/PD assessments are performed prior to dose escalation in all parts of the clinical trial.

Part 1 of this clinical trial enrolled five sequential cohorts of eight healthy subjects each (6 active: 2 placebo) receiving a single dose of AB-101 at increasing dose levels. In Part 1, all five evaluable subjects in the 40mg cohort showed evidence of 100% receptor occupancy. Part 2 of this clinical trial enrolled three sequential cohorts of ten healthy subjects that each received 10, 25 or 40mg of AB-101 (8 active: 2 placebo) daily for seven days. In Part 2, all subjects in the 40mg cohort showed evidence of high receptor occupancy between 74-100%, with six of the eight subjects demonstrating 100% receptor occupancy during the seven-day dosing period. Across Parts 1 and 2, eleven of the thirteen evaluable healthy subjects that received either single or multiple doses of 40mg of AB-101 achieved 100% receptor occupancy. The data from Part 1 and Part 2 showed that AB-101 was well-tolerated with evidence of high receptor occupancy.

Part 3 of this clinical trial evaluated repeat doses of AB-101 for 28 days in patients with cHBV. At the EASL Congress in May 2025, we presented data showing that a single dose of 10mg of AB-101 for 28 days in cHBV patients was well tolerated with PD-L1 receptor occupancy similar to that seen in healthy subjects at this dose. At the AASLD - The Liver Meeting in November 2025, we presented a Poster of Distinction highlighting maximal PD-L1 receptor occupancy between 68-100% at the 30mg daily dose. Treatment with AB-101 in Part 3 of this clinical trial was generally safe and well-tolerated. There were no serious adverse events related to AB-101 and no evidence of liver dysfunction.

Other Collaborations, Royalty Entitlements and Intellectual Property Litigation

Collaboration with Qilu Pharmaceutical Co., Ltd. (Qilu)

In December 2021, we entered into a technology transfer and license agreement (the Qilu License Agreement) with Qilu, pursuant to which we granted Qilu a sublicensable, royalty-bearing license, under certain intellectual property owned by us, which was non-exclusive as to development and manufacturing and exclusive with respect to commercialization of imdusiran, including pharmaceutical products that include imdusiran, for the treatment or prevention of hepatitis B in China, Hong Kong, Macau and Taiwan (Greater China and Taiwan).

Concurrent with the execution of the Qilu License Agreement, we entered into a Share Purchase Agreement (the Share Purchase Agreement) with Anchor Life Limited, a company established pursuant to the applicable laws and regulations of Hong Kong and an affiliate of Qilu (the Investor), pursuant to which the Investor purchased 3,579,952 of our common shares at

a purchase price of USD $4.19 per share, which was a 15% premium on the thirty-day average closing price of our common shares as of the close of trading on December 10, 2021 (the Share Transaction).

In June 2025, we and Qilu mutually agreed to conclude our strategic partnership and terminate the Qilu License Agreement and related agreements, and we now once again hold global rights for imdusiran. As no obligations remain under the Qilu License Agreement, we recognized all previously deferred revenue in the second quarter of 2025.

Alnylam Pharmaceuticals, Inc. (Alnylam) and Acuitas Therapeutics, Inc. (Acuitas)

In 2012, we entered into a license agreement with Alnylam that entitles Alnylam to develop and commercialize products with our LNP technology in exchange for milestone and royalty payments. We have two royalty entitlements to global net sales of ONPATTRO (Patisiran) (ONPATTRO), an RNA interference therapeutic currently being sold by Alnylam. 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 products.

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 December 31, 2025, an aggregate of $26.5 million of royalties have been earned by OMERS.

We also are receiving a second royalty interest ranging from 0.75% to 1.125% on global net sales of ONPATTRO, with 0.75% applying to sales greater than $500 million, originating from a settlement agreement and subsequent license agreement with Acuitas. This royalty entitlement from Acuitas has been retained by us and was not part of the royalty entitlement sale to OMERS.

In December 2025, we recognized revenue of $0.5 million following the achievement of a contractual milestone related to Alnylam’s use of our proprietary LNP technology in an additional product candidate to treat hepatocellular carcinoma (HCC), underscoring the important role our LNP technology plays in the delivery of nucleic acids to the body. We received this payment in January 2026.

Genevant Sciences, Ltd.

In April 2018, we entered into an agreement with Roivant Sciences Ltd. (Roivant), our largest shareholder, to launch Genevant Sciences Ltd., a company focused on nucleic acid- and gene editing-based therapeutics enabled by our LNP and ligand conjugate delivery technologies. We retained all rights to our LNP and conjugate delivery platforms for HBV.

The specified percentage is 20% in the case of a mere sublicense (i.e., naked sublicense) by Genevant without additional contribution and 14% in the case of a bona fide collaboration with Genevant.

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).

In July 2020, Roivant recapitalized Genevant through an equity investment and conversion of previously issued convertible debt securities held by Roivant. In connection with the recapitalization, the three parties entered into an Amended and Restated Shareholders Agreement that provides Roivant with substantial control of Genevant. We have the right to have a non-voting observer attend meetings of Genevant’s Board of Directors.

As of December 31, 2025, we owned approximately 16% of the common equity of Genevant and the carrying value of our investment in Genevant was zero. Our entitlement to receive future royalties or sublicensing revenue from Genevant was not impacted by the recapitalization.

Under the terms of the Moderna Settlement Agreement, Moderna will make an aggregate $950.0 million Noncontingent Settlement Payment to us and Genevant on or before July 8, 2026. 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. Under the Genevant License, we are entitled to receive, after deduction of litigation costs, 20% of the Noncontingent Settlement Payment, exclusive of our ownership of approximately 16% of the outstanding common equity of Genevant.

Patent Infringement Litigation vs. Pfizer and BioNTech

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.

Patent Infringement Litigation vs. Moderna

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. Together, these lawsuits comprise the Moderna LNP Litigation.

On March 3, 2026, we, Genevant, and, solely for specified purposes, Genevant Sciences Ltd., and Moderna entered into the Moderna Settlement Agreement 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 may 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.”

Under the terms of the Moderna Settlement Agreement, Moderna will make an aggregate $950.0 million Noncontingent Settlement Payment to us and Genevant on or before July 8, 2026.

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 or en 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 failure to timely file, or 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.

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

The Moderna Settlement Agreement includes mutual financial covenants to protect the payment or repayment of the Contingent Settlement Payment, as described above.

The Moderna Settlement Agreement also contains customary mutual releases in favor of each of us/Genevant and Moderna in respect of the Moderna LNP Litigation. In addition, the Moderna Settlement Agreement includes a fully paid-up, royalty free, irrevocable, non-exclusive, worldwide license and covenant not to sue granted to Moderna under any patents and patent applications owned or licensable by us or Genevant or our respective direct and indirect wholly owned subsidiaries that exist, or that claim priority to patents or patent applications that exist, as of the effective date of the Moderna Settlement Agreement, to make, sell and generally otherwise exploit Moderna’s SPIKEVAX™, mNEXSPIKE™ and mRESVIA™ vaccines and any other mRNA vaccines that include a lipid SM-102-based LNP formulation against an infectious disease and meet certain conditions, as well as a covenant not to sue with respect to certain other of our and Genevant’s patents and Moderna products.

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.

Moderna and Merck European Oppositions

On April 5, 2018, Moderna and Merck, Sharp & Dohme Corporation (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. A written decision is expected in the next few months. 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. 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 in the United States.

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.

While we are the patent owner, the ’254 Patent, the ’767 Patent, and the other patents in our LNP portfolio have been licensed to Genevant under the Genevant License.

Potential Additional Payments Related to the Acquisition of Enantigen Therapeutics, Inc.

In October 2014, Arbutus Inc., our wholly-owned subsidiary, acquired all of the outstanding shares of Enantigen Therapeutics, Inc. (Enantigen) pursuant to a stock purchase agreement.

Patents and Proprietary Rights

Our commercial success depends in part on our ability to obtain and maintain proprietary protection for our product candidates, novel discoveries, product development technologies and other know-how, to operate without infringing on the proprietary rights of others and to prevent others from infringing our proprietary rights. We also rely on trademarks, trade secrets, know how, continuing technological innovation and potential in-licensing opportunities to develop and maintain our proprietary position.

In Europe, upon grant, a period of nine months is allowed for notification of opposition to such granted patents.

Human Capital

Employee Composition

As of December 31, 2025, we had 19 full-time employees. In the first quarter of 2025, our Board took action to reduce our workforce by 57%, resulting in a total workforce after reductions of 19 employees. None of our employees are represented by a labor union or covered by a collective bargaining agreement, nor have we experienced any work stoppages. We believe that

relations with our employees are good. We supplement our in-house expertise with outsourced capabilities when it would be cost prohibitive to build our own in-house capabilities. For example, we outsource a substantial portion of our clinical trial work to clinical research organizations and a majority of our drug manufacturing is out-sourced to contract manufacturers.

Employee Oversight, Training and Development

We are invested in the professional development of our employees.

Compensation and Benefits

Drug development is a complex endeavor that requires deep expertise and attracting and retaining qualified employees for specialized biopharmaceutical positions. Our compensation programs are designed to attract and retain top talent. In addition, we offer mental health support to our employees and dependents.

We offer 25 paid days of time off and 13 days of paid holidays, in addition to a company closure during the last week of December. We provide paid parental leave to both birth and adoptive parents. In addition, during 2025, we shifted to remote work arrangements for all employees.

Environmental, Social and Governance

Environmental

We are a pre-commercial company engaged in clinical development with fewer than fifty employees. Manufacturing activities to support these activities is almost entirely outsourced, and biohazardous and chemical waste disposal is handled by third-party vendors. Our environmental footprint is small, and when we exited our Warminster, Pennsylvania, headquarters in March 2025, we shifted to a remote work model which further reduced our environmental footprint.

Social

The culture at Arbutus reflects our commitment to our employees, to our community, and to making a meaningful contribution to world health.

Diversity

Our commitment to diversity is demonstrated by our placement of ultimate responsibility for diversity with our Board, informed by the recommendations of management and our Board’s Nominating and Governance Committee.

Our Contribution to World Health

We are dedicated to meaningfully contributing to world health. We are pursuing the mission of developing a functional cure for hepatitis B viral infections, an unmet medical need affecting over 250 million people worldwide.

Governance

As stated in our Code of Conduct, we are committed to complying with all applicable laws, rules and regulations not just in the United States and Canada, but in all the countries in which we operate. All vendors also receive our Code of Conduct at the time of their engagement with us.

Competition

We face a broad range of current and potential competitors, from established global pharmaceutical companies with significant resources, to research-stage companies. In addition, we face competition from academic and research institutions and government agencies for the discovery, development and commercialization of novel therapeutics to treat HBV. Many of our competitors, either alone or with their collaborative partners, have significantly greater financial, product development, technical, manufacturing, sales, and marketing resources than we do.

As a significant unmet medical need exists for HBV, there are several large and small pharmaceutical companies focused on delivering singular or combinations of therapeutics for the treatment of HBV. These companies include, but are not limited to, GSK plc, Gilead Sciences, Inc., Assembly Biosciences, Inc., Aligos Therapeutics, Inc., AusperBio Therapeutics, Inc., Brii Biosciences Limited, Mirum Pharmaceuticals, Inc., and Precision Biosciences, Inc. These product candidates are in various stages of preclinical and clinical development. Further, in addition to current investigational therapeutics in development, it is likely that additional drugs will become available in the future for the treatment of HBV.

We anticipate that we will face competition as new products enter the marketplace. Our competitors’ products may be safer, more effective, or more effectively marketed and sold than any product we may commercialize. Competitive singular or combination products may render one or more of our product candidates obsolete or non-competitive before we can recover the expenses of developing and commercializing any of our product candidates.

We believe that our ability to compete depends, in part, upon our ability to successfully complete clinical trials and regulatory approval processes, and effectively market any approved products.

Manufacturing

We currently rely on third-party manufacturers to supply drug substance and drug products, including imdusiran and AB-101, for our ongoing and anticipated clinical trials and non-clinical studies. We currently have no plans to establish any large-scale internal manufacturing facilities for our product candidates.

Government Regulation

Regulation by governmental authorities in the United States and in other countries is a significant consideration in our product development, manufacturing and, if our product candidates are approved, marketing strategies. We expect that all our product candidates will require regulatory approval by the FDA and by similar regulatory authorities in foreign countries prior to commercialization and will be subjected to rigorous preclinical, clinical, and post-approval testing to demonstrate safety and effectiveness, as well as other significant regulatory requirements and restrictions in each jurisdiction in which we would seek to market our products. In the United States, we are subject to extensive regulation by the FDA and other federal, state, and local regulatory agencies. United States federal laws, such as the Federal Food, Drug, and Cosmetic Act (FD&C Act), and regulations issued thereunder, govern the testing, development, manufacture, quality control, safety, effectiveness, approval, storage, labeling, record keeping, reporting, distribution, import, export, sale, and marketing of all biopharmaceutical products intended for therapeutic purposes. We believe that we and the third parties that work with us are in compliance in all material respects with currently applicable laws, rules and regulations; however, any failure to comply could have a material negative impact on our ability to successfully develop and commercialize our products, and therefore on our financial performance. In addition, the laws, rules and regulations that apply to our business are subject to change and it is difficult to foresee whether, how, or when such changes may affect our business.

Obtaining governmental approvals to market our product candidates and maintaining ongoing compliance with applicable federal, state, local and foreign statutes and regulations following any such approvals will require the expenditure of significant financial and human resources.

Development and Approval

The process to develop and obtain approval for biopharmaceutical products for commercialization in the United States and many other countries is lengthy, complex and expensive, and the outcome is far from certain. Although foreign requirements for conducting clinical trials and obtaining approval may differ in certain respects from those in the United States, there are many similarities and they often are equally rigorous, and the outcome cannot be predicted with confidence. A key component of any submission for approval in any jurisdiction is preclinical and clinical data demonstrating the product candidate’s safety and effectiveness.

Preclinical Testing. Before testing any product candidate in humans in the United States, a company must develop preclinical data, generally including laboratory evaluation of the product candidate’s chemistry and formulation, as well as toxicological and pharmacological studies, potentially in animal species, to assess safety and quality. Certain types of animal studies must be conducted in compliance with the FDA’s Good Laboratory Practice (GLP) regulations and the Animal Welfare Act, which is enforced by the Department of Agriculture.

IND Application. A person or entity sponsoring clinical trials in the United States to evaluate a product candidate’s safety and effectiveness must submit to the FDA, prior to commencing such trials, an investigational new drug (IND) application, which contains, among other data and information, preclinical testing results and provides a basis for the FDA to conclude that there is an adequate basis for testing the drug in humans. If the FDA does not object to the IND application within 30 days of submission, the clinical testing proposed in the IND may begin. Even after the IND has gone into effect and clinical testing has begun, the FDA may put the clinical trials on “clinical hold,” suspending (or in some cases, ending) them because of safety concerns or for other reasons.

Clinical Trials. Clinical trials involve administering a product candidate to human volunteers or patients under the supervision of a qualified clinical investigator. Clinical trials are subject to extensive regulation. In the United States, this includes compliance with the FDA’s bioresearch monitoring regulations and current good clinical practices (GCP) requirements, which establish standards for conducting, recording data from, and reporting the results of clinical trials, with the goals of assuring that the data and results are credible and accurate and that study participants’ rights, safety and well-being are protected. Each clinical trial must be conducted under a protocol that details, among other things, the study objectives and parameters for monitoring safety and the efficacy criteria, if any, to be evaluated. The protocol is submitted to the FDA as part of the IND and reviewed by the agency. Additionally, each clinical trial must be reviewed, approved and conducted under the auspices of an Institutional Review Board (IRB). The sponsor of a clinical trial, the investigators and IRBs each must comply with requirements and restrictions that govern, among other things, obtaining informed consent from each study subject, complying

with the protocol and investigational plan, adequately monitoring the clinical trial, and timely reporting adverse effects. Foreign studies conducted under an IND must meet the same requirements applicable to studies conducted in the United States. However, if a foreign study is not conducted under an IND, the data may still be submitted to the FDA in support of a product application, if the study was conducted in accordance with GCP and the FDA is able to validate the data.

The sponsor of a clinical trial or the sponsor’s designated responsible party may be required to register certain information about the trial and disclose certain results on government or independent registry websites, such as clinicaltrials.gov.

Clinical testing is typically performed in three phases, which may overlap or be subdivided in some cases.

In Phase 1 trials, the product candidate is administered to a small number of human subjects to assess its safety and to develop detailed profiles of its pharmacological and pharmacokinetic actions (i.e., absorption, distribution, metabolism and excretion), assess the early safety profile, determine side effects associated with increasing doses, and, if possible, gain early evidence of effectiveness. Although Phase 1 trials are typically conducted in healthy human subjects, in some instances (including, for example, with some cancer therapies) the trial subjects are patients with the targeted disease or condition.

In Phase 2 trials, the product candidate is administered to a relatively small sample of the intended patient population to develop initial data regarding efficacy in the targeted disease, determine the optimal dose range, and generate additional information regarding the product candidate’s safety. Additional animal toxicology studies may precede this phase.

Typically, Phase 3 trials are conducted at multiple study sites and may be conducted concurrently for the sake of time and efficiency. The purpose of Phase 3 clinical trials is to obtain additional information about safety and effectiveness necessary to evaluate the product candidate’s overall risk-benefit profile and to provide a basis for product labeling. Phase 3 data often form the core basis on which the FDA evaluates a product candidate’s safety and effectiveness when considering the product application.

The study sponsor, the FDA or an IRB may suspend or terminate a clinical trial at any time on various grounds, including a determination that study subjects are being exposed to an unacceptable health risk. Success in early-stage clinical trials does not assure success in later-stage clinical trials. Moreover, data from clinical trials are not always conclusive and may be subject to alternative interpretations that could delay, limit or prevent approval.

When a clinical trial is carried out in the European Union, the Clinical Trials Regulation (CTR) provides the regulatory framework. On January 31, 2022, this CTR repealed the Clinical Trials Directive (CTD) and national implementing legislation in the European Union Member States. From January 31, 2025, all trials approved under the old CTD that continue running after this date, will need to comply with the new CTR. Until January 30, 2023, clinical trial sponsors could choose whether to start a new clinical trial under the CTD or under the new CTR. However, from January 31, 2023 onwards, new clinical trials would automatically fall under the scope of the new CTR. The main characteristics of the CTR include: a streamlined application procedure to the EMA through a single entry point, the “Clinical Trials Information System” enabling sponsors to apply for clinical trial authorization in up to 30 European countries; a single set of documents to be prepared and submitted for the application as well as simplified reporting procedures for clinical trial sponsors; and a harmonized procedure for the assessment of applications for clinical trials.

NDA Submission and Review. After completing the clinical studies, a sponsor seeking approval to market a product candidate in the United States submits to the FDA a New Drug Application (NDA). The NDA is a comprehensive application intended to demonstrate the product candidate’s safety and effectiveness and includes, among other things, preclinical and clinical data, information about the product candidate’s composition, the sponsor’s plans for manufacturing and packaging and proposed labeling. When an NDA is submitted, the FDA makes an initial determination as to whether the application is sufficiently complete to be accepted for review. If the application is not, the FDA may refuse to accept the NDA for filing and request additional information. A refusal to file, which requires resubmission of the NDA with the requested additional information, delays review of the application.

FDA performance goals generally provide for action on an NDA within 10 months of the 60-day filing date, or within 12 months of the NDA submission. That deadline can be extended under certain circumstances, including by the FDA’s requests

for additional information. The FDA has other programs to expedite development and review of product candidates that address serious or life-threatening conditions. For example, the Fast Track program is intended to facilitate the development and review of new drugs that demonstrate the potential to address unmet medical needs involving serious or life-threatening diseases or conditions. If a product candidate receives Fast Track designation, the FDA may review sections of the NDA on a rolling basis, rather than requiring the entire application to be submitted to begin the review. Product candidates with Fast Track designation also may be eligible for more frequent meetings and correspondence with the FDA about the product candidate’s development. Another FDA program intended to expedite development is the Accelerated Approval pathway, which allows approval on the basis of a surrogate endpoint that is reasonably likely to predict clinical benefit or on an intermediate clinical endpoint that is reasonably likely to predict clinical benefit. To qualify for review under the Accelerated Approval pathway, a product candidate must treat a serious condition, provide a meaningful advantage over available therapies, and demonstrate an effect on a surrogate endpoint that is reasonably likely to predict clinical benefit or on an intermediate clinical endpoint. On December 29, 2022, Congress enacted the Consolidated Appropriations Act of 2023, which included several changes to the Accelerated Approval pathway within the Food and Drug Omnibus Reform Act (FDORA).

FDORA gives the agency significant flexibility in setting forth such conditions, which may include enrollment targets, study protocol and milestones—including the target date of study completion. The FDA may also require, as appropriate, that certain post-approval studies be underway prior to Accelerated Approval or within a specified time from the date of approval. Accelerated Approval sponsors are required to report progress every six months on required post-approval trials. Breakthrough Therapy designation, which is available for product candidates under development for serious or life-threatening conditions and where preliminary clinical evidence shows that the product candidate may have substantial improvement on at least one clinically significant endpoint over available therapies, means that a product candidate will be eligible for all of the benefits of Fast Track designation, as well as more intensive guidance from the FDA on an efficient drug development program and a commitment from the agency to involve senior FDA managers in such guidance. Even if a product candidate qualifies for Fast Track designation or Breakthrough Therapy designation, the FDA may later decide that the product no longer meets the conditions for designation and may rescind the designation, and/or may determine that the product does not meet the standards for approval. As applicable, we anticipate seeking to utilize these programs to expedite the development and review of our product candidates, but we cannot ensure that our product candidates will qualify for such programs, or that we will be able to maintain such designations if we qualify for such programs.

For some NDAs, the FDA may convene an advisory committee to seek insights and recommendations on issues relevant to approval of the application. Although the FDA is not bound by the recommendation of an advisory committee, the agency considers such recommendations carefully when making decisions. Before approving a new drug product, the FDA also requires that the facilities at which the product will be manufactured or advanced through the supply chain be in compliance with current good manufacturing practices (GMP) requirements and regulations governing, among other things, the manufacture, shipment, and storage of the product. The FDA also can conduct audits to determine if the clinical trials were conducted in compliance with GCP. After review of an NDA, the FDA may grant marketing approval, request additional information, or issue a complete response letter (CRL) communicating the reasons for the agency’s decision not to approve the application. The CRL may request additional information, including additional preclinical or clinical data, for the FDA to reconsider the application. An NDA may be resubmitted with the deficiencies addressed, but resubmission does not guarantee approval. Data from clinical trials are not always conclusive, and the FDA’s interpretation of data may differ from the sponsor’s. Obtaining approval can take years, requires substantial resources and depends on a number of factors, including the severity of the targeted disease or condition, the availability of alternative treatments, and the risks and benefits demonstrated in clinical trials. Additionally, as a condition of approval, the FDA may impose restrictions that could affect the commercial prospects of a product and increase our costs, such as a Risk Evaluation and Mitigation Strategy (REMS), and/or post-marketing requirements to conduct additional clinical trials or non-clinical studies or to conduct surveillance programs to monitor the product’s effects. Under the Pediatric Research Equity Act (PREA), certain applications for approval must also include an assessment, generally based on clinical study data, of the safety and effectiveness of the subject product in relevant pediatric populations, unless a waiver or deferral is granted.

Moreover, once a product is approved, information about its safety or effectiveness from broader clinical use may limit or prevent successful commercialization because of regulatory action, market forces or for other reasons. Post-approval modifications to a drug product, such as changes in indications, labeling or manufacturing processes or facilities, may require development and submission of additional information or data in a new or supplemental NDA, which would also require prior FDA approval.

Competition. The Drug Price Competition and Patent Term Restoration Act of 1984 (the Hatch-Waxman Act) establishes two abbreviated approval pathways for product candidates that are in some way follow-on versions of already approved branded NDA products: (i) generic versions of the approved reference listed drug (RLD), which may be approved under an abbreviated new drug application (ANDA) by showing that the generic product is the “same as” the approved product in key respects; and (ii) a product that is similar but not identical to a listed drug, which may be approved under a 505(b)(2) NDA, in which the sponsor relies to some degree on information from investigations that were not conducted by or for the applicant and for which the applicant has not obtained a right of reference, and submits its own product-specific data to support the differences between the product and the listed drug.

The sponsor of an ANDA or 505(b)(2) application seeking to rely on an approved product as the RLD or listed drug must make one of several certifications regarding each patent for the RLD that is listed in the FDA publication, Approved Drug Products with Therapeutic Equivalence Evaluations, which is referred to as the Orange Book. A “Paragraph I” certification is the sponsor’s statement that patent information has not been filed for the RLD. A “Paragraph II” certification is the sponsor’s statement that the RLD’s patents have expired. A “Paragraph III” certification is the sponsor’s statement that it will wait for the patent to expire before obtaining approval for its product. A “Paragraph IV” certification is an assertion that the patent does not block approval of the later product, either because the patent is invalid or unenforceable or because the patent, even if valid, is not infringed by the new product. Once the FDA accepts for filing an ANDA or 505(b)(2) application containing a Paragraph IV certification, the applicant must within 20 days provide notice to the RLD or listed drug NDA holder and patent owner that the application has been submitted and provide the factual and legal basis for the applicant’s assertion that the patent is invalid or not infringed. If the NDA holder or patent owner files suit against the ANDA or 505(b)(2) applicant for patent infringement within 45 days of receiving the Paragraph IV notice, the FDA is prohibited from approving the ANDA or 505(b)(2) application for a period of 30 months or the resolution of the underlying suit, whichever is earlier.

In the United States and elsewhere, certain regulatory exclusivities and patent rights can provide an approved drug product with protection from certain competitors’ products for a period of time and within a certain scope. In the United States, those protections include regulatory exclusivity under the Hatch-Waxman Act, which provides periods of exclusivity for a branded drug product that would serve as an RLD for a generic drug applicant filing and an ANDA under section 505(j) of the FD&C Act or as a listed drug for an applicant filing an NDA under section 505(b)(2) of the FD&C Act. If such a product is a “new chemical entity” (NCE) generally meaning that the active moiety has never before been approved in any drug, there is a period of five years from the product’s approval during which the FDA may not accept for filing any ANDA or 505(b)(2) application for a drug with the same active moiety. An ANDA or 505(b)(2) application may be submitted after four years, however, if the sponsor of the application makes a Paragraph IV certification (as described above). Such a product that is not an NCE may qualify for a three-year period of exclusivity if its NDA contains new clinical data (other than bioavailability studies), derived from studies conducted by or for the sponsor, that were necessary for approval. In this instance, the three-year exclusivity period does not preclude filing or review of an ANDA or 505(b)(2) application; rather, the FDA is precluded from granting final approval to the ANDA or 505(b)(2) application until three years after approval of the RLD. This three-year exclusivity applies only to the conditions of approval that required submission of the clinical data.

The Hatch-Waxman Act also provides for the restoration of a portion of the patent term lost during product development and FDA review of an NDA if approval of the application is the first permitted commercial marketing of a drug containing the active ingredient. The patent term restoration period is generally one-half the time between the effective date of the IND or the date of patent grant (whichever is later) and the date of submission of the NDA, plus the time between the date of submission of the NDA and the date of FDA approval of the product. The maximum period of restoration is five years, and the patent cannot be extended to more than 14 years from the date of FDA approval of the product. Only one patent claiming each approved product is eligible for restoration and the patent holder must apply for restoration within 60 days of approval. The USPTO, in consultation with the FDA, reviews and approves the application for patent term restoration.

In the European Union, new medicinal products are granted a protection period of eight years of data exclusivity and an additional two years of market exclusivity. As such, for a period of eight years, generics cannot use the data of the innovator to obtain a marketing authorization. Only after eight years have lapsed, other parties that apply for a marketing authorization (generics or biosimilars) may make reference to the dossier of the originator product. Only after another two years (i.e., a total of ten years) may a generic or biosimilar medicinal product be placed on the market.

In April 2023, the European Commission published a proposal to reform this system. The European Commission, European Parliament and European Council reached an agreement in December 2025. Under the agreed revision, regulatory data protection will consist of eight years of data exclusivity and one additional year of market exclusivity. This means a total of nine years of protection, instead of the current 10 years. Under the reformed legislation, there will be a possibility to obtain one additional year of exclusivity under certain circumstances and another year for a new indication of significant clinical benefit, with a capped overall regulatory protection of 11 years. The final text of the reform proposal is expected to be endorsed and published in the first half of 2026 and, after a transition period, the new legislation is expected to start to apply beginning in mid-2028.

Post-Approval Regulation

Once approved, drug products are subject to continuing extensive regulation by the FDA, including ongoing monitoring for safety information, maintaining appropriate registrations and licenses, and hosting periodic inspections. If ongoing regulatory requirements are not met, or if safety problems occur after a product reaches market, the FDA may take actions to change the conditions under which the product is marketed, such as requiring labeling modifications, restricting distribution, or even withdrawing approval. In addition to FDA regulation, our business is also subject to extensive federal, state, local and foreign regulation.

Good Manufacturing Practices. Companies engaged in manufacturing drug products or their components must comply with applicable GMP requirements, which include requirements regarding organization and training of personnel, building and facilities, equipment, control of components and drug product containers, closures, production and process controls, packaging and labeling controls, holding and distribution, laboratory controls and records and reports. The FDA inspects equipment, facilities and manufacturing processes before approval and conducts periodic re-inspections after approval. Failure to comply with applicable GMP requirements or the conditions of the product’s approval may lead the FDA to take enforcement actions, such as issuing a warning letter, or to seek sanctions, including fines, civil penalties, injunctions, suspension of manufacturing operations, imposition of operating restrictions, withdrawal of FDA approval, seizure or recall of products, and criminal prosecution. Although we periodically monitor FDA compliance of the third parties on which we rely for manufacturing our product candidates, we cannot be certain that our present or future third-party manufacturers will consistently comply with GMP or other applicable FDA regulatory requirements.

Sales and Marketing. Once a product is approved, the advertising, promotion and marketing of the product will be subject to close regulation, including with regard to promotion to healthcare practitioners, direct-to-consumer advertising, communications regarding unapproved uses, industry-sponsored scientific and educational activities and promotional activities involving the internet. In addition to FDA restrictions on marketing of pharmaceutical products, state and federal fraud and abuse laws have been applied to restrict certain marketing practices in the pharmaceutical industry. Failure to comply with applicable requirements in this area may subject a company to adverse publicity, investigations and enforcement action by the FDA, the Department of Justice, the Office of the Inspector General of the Department of Health and Human Services, and/or state authorities. This could subject a company to a range of penalties that could have a significant commercial impact, including civil and criminal fines and agreements that materially restrict the manner in which a company promotes or distributes drug products.

New Legislation. Further, the FDA revises its regulations and guidance in light of new legislation or may revise, withdraw, or issue new regulations and guidance in light of the priorities of the new presidential administration in ways that may affect our business or product candidates. It is

impossible to predict whether other changes to legislation, regulation, or guidance will be enacted, or what the impact of such changes, if any, may be.

However, an important and foreseeable example of new legislation is the forthcoming European Union pharmaceutical legislation revision. The European Commission presented a legislative proposal in April 2023 that would change European Union pharmaceutical law with respect to for example regulatory data exclusivity, environmental risk assessment, medicines shortages and other topics. In December 2025, the European Commission, European Parliament and the European Council reached an agreement on pharmaceutical reform. The final text of the reform proposal is expected to be endorsed and published in the first half of 2026 and, after a transition period, the new legislation is expected to start to apply beginning in mid-2028.

Other Requirements. Companies that manufacture or distribute drug products pursuant to approved NDAs must meet numerous other regulatory requirements, including adverse event reporting, submission of periodic reports, and record-keeping obligations.

Fraud and Abuse Laws. At such time as we market, sell and distribute any products for which we obtain marketing approval, it is possible that our business activities could be subject to scrutiny and enforcement under one or more federal or state health care fraud and abuse laws and regulations, which may constrain the business or financial arrangements and relationships through which we market, sell and distribute any products for which we obtain marketing approval. The applicable federal and state health care fraud and abuse laws and regulations that may affect our ability to operate include:

•The United States federal Anti-Kickback Law, which prohibits, among other things, knowingly or willingly offering, paying, soliciting or receiving remuneration, directly or indirectly, in cash or in kind, to induce or reward the purchasing, leasing, ordering or arranging for or recommending the purchase, lease or order of any health care items or service for which payment may be made, in whole or in part, by federal healthcare programs such as Medicare and Medicaid. This statute has been interpreted to apply to arrangements between pharmaceutical companies on one hand and prescribers, purchasers and formulary managers on the other.

•The United States federal civil False Claims Act, which prohibits, among other things, individuals or entities from knowingly presenting, or causing to be presented, a false or fraudulent claim for payment of government funds or knowingly making, using or causing to be made or used, a false record or statement material to an obligation to pay money to the government or knowingly concealing or knowingly and improperly avoiding, decreasing or concealing an obligation to pay money to the federal government. Actions under the False Claims Act may be brought by the United States Attorney General or as a qui tam action by a private individual (a whistleblower) in the name of the government and the individual, and the whistleblower may share in any monetary recovery. Many pharmaceutical and other healthcare companies have been investigated and have reached substantial financial settlements with the federal government under the civil False Claims Act for a variety of alleged improper marketing activities, including: providing free product to customers with the expectation that the customers would bill federal programs for the product; providing sham consulting fees, grants, free travel and other benefits to physicians to induce them to prescribe the company’s products; and inflating prices reported to private price publication services, which are used to set drug payment rates under government healthcare programs. Pharmaceutical and other healthcare companies also are subject to other federal false claim laws, including, among others, federal criminal healthcare fraud and false statement statutes that extend to non-government health benefit programs.

•The fraud provisions of the Health Insurance Portability and Accountability Act of 1996 and its implementing regulations (collectively, HIPAA), which impose criminal liability for knowingly and willfully executing a scheme to defraud any healthcare benefit program, including private third-party payors, and prohibit knowingly and willfully falsifying, concealing or covering up a material fact or making any materially false, fictitious or fraudulent statement or representation, or making or using any false writing or document knowing the same to contain any materially false fictitious or fraudulent statement or entry, in connection with the delivery of or payment for healthcare benefits, items or services.

•Analogous state and local laws and regulations, such as state anti-kickback and false claims laws, which may apply to sales or marketing arrangements and claims involving healthcare items or services reimbursed by non-governmental third-party payors, including private insurers; state and foreign laws that require pharmaceutical companies to comply with the pharmaceutical industry’s voluntary compliance guidelines and the relevant compliance guidance promulgated by the federal government or otherwise restrict payments that may be made to healthcare providers; state laws that restrict the ability of manufacturers to offer co-pay support to patients for certain prescription drugs; and state and foreign laws that require drug manufacturers to report information related to clinical trials, or information related to payments and other transfers of value to physicians and other healthcare providers or marketing expenditures; state laws and local ordinances that require identification or licensing of sales representatives.

•The United States federal Physician Payment Sunshine Act, being implemented as the Open Payments Program, which requires manufacturers of drugs, devices, biologics, and medical supplies for which payment is available under Medicare, Medicaid or the Children’s Health Insurance Program (with certain exceptions) to report annually to the Centers for Medicare and Medicaid Services (CMS) information related to direct or indirect payments and other transfers of value to physicians, physician assistants, nurse practitioners, clinical nurse specialists, certified nurse anesthetists, certified nurse-midwives, and teaching hospitals, as well as ownership and investment interests held in the company by physicians and their immediate family members.

•The federal Foreign Corrupt Practices Act of 1997 and other similar anti-bribery laws in other jurisdictions generally prohibit companies and their intermediaries from providing money or anything of value to officials of foreign governments, foreign political parties or international organizations with the intent to obtain or retain business or seek a business advantage. Recently, there has been a substantial increase in anti-bribery law enforcement activity by United States regulators, with more frequent and aggressive investigations and enforcement proceedings by both the Department of Justice and the United States Securities and Exchange Commission (the SEC). Violations of United States or foreign laws or regulations could result in the imposition of substantial fines, interruptions of business, loss of supplier, vendor or other third-party relationships, termination of necessary licenses and permits and other legal or equitable sanctions. Other internal or government investigations or legal or regulatory proceedings, including lawsuits brought by private litigants, may also follow as a consequence.

Although compliance programs can mitigate the risk of investigation and prosecution for violations of these laws, the risks cannot be entirely eliminated. Moreover, achieving and sustaining compliance with applicable federal and state privacy, security and fraud laws may prove costly.

Privacy Laws. The legislative and regulatory landscape for privacy and data protection continues to evolve, and there has been an increasing focus on privacy and data protection issues that may affect our business, including recently enacted laws in all jurisdictions where we operate. Federal regulators, state attorneys general, and plaintiffs’ attorneys have been and will likely continue to be active in this space. Activities outside of the United States implicate local and national data protection standards, impose additional compliance requirements and generate

additional risks of enforcement for non-compliance. The European Union’s General Data Protection Regulation (EU GDPR), the United Kingdom’s General Data Protection Regulation (UK GDPR and together with EU GDPR, GDPR) and other data protection, privacy and similar national, state/provincial and local laws may restrict the access, use, storage, disclosure and other processing activities concerning patient health information abroad. Compliance efforts will likely be an increasing and substantial cost in the future.

Failure to comply with such laws and regulations could result in government enforcement actions and create liability for us (including the imposition of significant penalties), private litigation and/or adverse publicity that could negatively affect our business.

The Federal Trade Commission (FTC) also sets expectations for failing to take appropriate steps to keep consumers’ personal information secure, or failing to provide a level of security commensurate to promises made to individual about the security of their personal information (such as in a privacy notice), which may constitute unfair or deceptive acts or practices in violation of Section 5(a) of the FTC Act. The FTC expects a company’s data security measures to be reasonable and appropriate in light of the sensitivity and volume of consumer information it holds, the size and complexity of its business, and the cost of available tools to improve security and reduce vulnerabilities. Individually identifiable health information is considered sensitive data that merits stronger safeguards. With respect to privacy, the FTC also sets expectations for failing to honor the privacy promises made to individuals about how the company handles consumers’ personal information; such failure may also constitute unfair or deceptive acts or practices in violation of the FTC Act. The FTC also has the power to enforce the Health Breach Notification Rule, which imposes notification obligations on companies for breaches of certain health information contained in personal health records. The FTC has brought enforcement actions under both Section 5 of the FTC Act and the Health Breach Notification Rule.

In California, the CCPA establishes certain requirements for processing personal data, including obligations related to transparency and the collection, use, retention, and disclosure of personal data, and provides California residents certain rights concerning the use, correction, disclosure, and retention of their personal information. The CCPA and its implementing regulations have already been amended multiple times since their enactment. In November 2020, California voters approved the California Privacy Rights Act (CPRA) ballot initiative which introduced significant amendments to the CCPA and established and funded a dedicated California privacy regulator, the California Privacy Protection Agency (CPPA). The amendments introduced by the CPRA went into effect on January 1, 2023, and implementing regulations regulating automatic decision-making technologies, cyber audits, and risk assessments went into effect on January 1, 2026. Failure to comply with the CCPA may result in, among other things, significant civil penalties and injunctive relief, or statutory or actual damages. In addition, California residents have the right to bring a private right of action in connection with certain types of incidents. These claims may result in significant liability and damages. Nearly two dozen other states have enacted privacy laws similar to the CCPA that impose obligations or limitations in areas affecting our business and we continue to assess the impact of such state legislation on our business as additional information and guidance becomes available. Similarly, there are a number of legislative proposals in the United States, at both the federal and state level, that could impose new obligations or limitations in areas affecting our business. These laws and regulations are evolving and subject to interpretation, and may impose limitations on our activities or otherwise adversely affect our business. Health-specific consumer privacy laws were also passed in multiple states, including Washington and Nevada. These laws and regulations are constantly evolving and may impose limitations on our business activities.

We may be required to expend significant capital and other resources to ensure ongoing compliance with applicable privacy, data protection and cybersecurity laws, to protect against cybersecurity incidents, to notify competent authorities and impacted individuals in the event of a cybersecurity incident, and to alleviate

problems caused by such cybersecurity incidents. Compliance with these laws is difficult, constantly evolving, time consuming, and requires a flexible privacy framework and substantial resources. Compliance efforts will likely be an increasing and substantial cost in the future. These laws and regulations, as well as any associated claims, inquiries, or investigations or any other government actions may lead to unfavorable outcomes including increased compliance costs, delays or impediments in the development of new products, negative publicity, increased operating costs, diversion of management time and attention, and remedies that harm our business, including fines or demands or orders that we modify or cease existing business practices. The GDPR imposes significant fines and other administrative penalties to which we could be subject in the event of any non-compliance, including fines of up to EUR 10,000,000 or up to 2% of our total worldwide annual turnover for certain comparatively minor offenses, or up to EUR 20,000,000 or up to 4% of our total worldwide annual turnover for more serious offenses. The GDPR also confers a private right of action on data subjects and consumer associations to lodge complaints with data protection authorities, seek judicial remedies, and obtain compensation for damages resulting from violations of the GDPR.

With regard to the transfer of personal data, the EU GDPR generally restricts the ability of companies to transfer personal data from the European Economic Area to the United States and other countries without a valid transfer mechanism, which may adversely affect our ability to transfer personal data or otherwise may cause us to incur significant costs for implementing lawful transfer mechanisms, conducting data transfer impact assessments, and implementing additional measures where necessary to ensure that personal data transferred are adequately protected in a manner essentially equivalent to the EU. The EU GDPR provides different transfer mechanisms we can use to lawfully transfer personal data from the EU to countries outside the EU. An example is relying on adequacy decisions of the European Commission, such as the EU-U.S. Data Privacy Framework which was adopted by the European Commission in July 2023. The adequacy decision concludes that the United States ensures an adequate level of protection (compared to that of the EU) for personal data transferred from the EU to United States companies participating in the EU-U.S. Data Privacy Framework. The adequacy decisions of the European Commission are subject to periodic reviews and may be amended or withdrawn. Another example of a lawful transfer mechanism is using the EU Standard Contractual Clauses as approved by the European Commission in June 2021, which are the most common used transfer mechanism used to transfer personal data out of the EU. In order to use the EU Standard Contractual Clauses mechanism, the data exporter and the data importer must ensure that the data importer guarantees a level of personal data protection in the importing country that is essentially equivalent to that of the European Economic Area. Compliance with EU data transfer obligations involves conducting transfer impact assessments, which includes documenting detailed analyses of data access and protection laws in the countries in which data importers are located, which can be costly and time-consuming. Data importers must also expend resources in analyzing their ability to comply with transfer obligations, including implementing new safeguards and controls to further protect personal data.

Artificial intelligence. As a result of the broad-scale release and availability of Artificial Intelligence (AI) technologies, such as generative AI, there is a global trend towards more regulation (e.g., the EU AI Act and AI laws passed in U.S. states) to ensure the ethical and lawful use of AI, and the privacy and security of such AI and the data that it processes.

Coverage and Reimbursement

Significant uncertainty exists as to the coverage and reimbursement status of any product candidates for which we may obtain regulatory approval and commercialize. The regulations that govern marketing approvals, pricing and reimbursement for new drug products vary widely from country to country. Current and future legislation may significantly change the approval requirements in ways that could involve additional costs and cause delays in obtaining approvals. In many countries, the pricing review period begins after marketing or product licensing approval is granted. In some foreign markets, prescription pharmaceutical pricing remains subject to continuing governmental control even after initial approval is granted. As a result, we might obtain marketing approval for a product in a particular country, but then be subject to price regulations that delay our commercial launch of the product, possibly for lengthy time periods, which could negatively impact the revenues we are able to generate from the sale of

the product in that particular country. Adverse pricing limitations may hinder our ability to recoup our investment in one or more product candidates even if our product candidates obtain marketing approval.

Government authorities and other third-party payors, such as private health insurers and health maintenance organizations, determine which medications they will cover and establish reimbursement levels. Third-party payors may limit coverage to specific products on an approved list, or formulary, which may not include all of the FDA-approved products for a particular indication. The process for determining whether a payor will provide coverage for a product may be separate from the process for setting the price or reimbursement rate that the payor will pay for the product once coverage is approved.

Government healthcare programs and other third-party payors are increasingly challenging the prices charged for medical products and services and examining the medical necessity and cost-effectiveness of medical products and services, in addition to their safety and efficacy, and have attempted to control costs by limiting coverage and the amount of reimbursement for particular medications. Increasingly, third-party payors are requiring that drug companies provide them with predetermined discounts from list prices and are challenging the prices charged for medical products. We cannot be sure that coverage and reimbursement will be available promptly or at all for any product that we commercialize and, if reimbursement is available, what the level of reimbursement will be. Moreover, eligibility for coverage and reimbursement does not imply that any drug will be paid for in all cases. Limited coverage may impact the demand for, or the price of, any product candidate for which we obtain marketing approval. If coverage and reimbursement are not available or reimbursement is available only to limited levels, we may not successfully commercialize any product candidate for which we obtain marketing approval.

Obtaining coverage and adequate reimbursement is a time-consuming and costly process. There may be significant delays in obtaining coverage and reimbursement for newly approved drugs, and coverage may be more limited than the purposes for which the drug is approved by the FDA or comparable foreign regulatory authorities. Moreover, eligibility for coverage and reimbursement does not imply that a drug will be paid for in all cases or at a rate that covers our costs, including research, development, manufacture, sale and distribution. Interim reimbursement levels for new drugs, if applicable, may also not be sufficient to cover our costs and may only be temporary. Reimbursement rates may vary according to the use of the drug and the clinical setting in which it is used, may be based on reimbursement levels already set for lower cost drugs and may be incorporated into existing payments for other services. Net prices for drugs may be reduced by mandatory discounts or rebates required by government healthcare programs or private payors and by any future relaxation of laws that presently restrict imports of drugs from countries where they may be sold at lower prices than in the United States. Limited coverage may impact the demand for, or the price of, any product candidate for which we obtain marketing approval. Third-party payors also may seek additional clinical evidence, including expensive pharmacoeconomic studies, beyond the data required to obtain marketing approval, demonstrating clinical benefits and value in specific patient populations, before covering our products for those patients. If reimbursement is available only for limited indications, we may not be able to successfully commercialize any product candidate for which we obtain marketing approval. Our inability to promptly obtain coverage and profitable reimbursement rates from both government-funded and private payors for any approved products that we develop could have a material adverse effect on our operating results, our ability to raise capital needed to commercialize products and our overall financial condition.

Government Price Reporting

If we successfully commercialize any of our products, we may participate in the Medicaid Drug Rebate Program. Participation is required for federal funds to be available for our products under Medicaid and Medicare Part B. Under the Medicaid Drug Rebate Program, we would be required to pay a rebate to each state Medicaid program for our covered outpatient drugs that are dispensed to Medicaid beneficiaries and paid for by a state Medicaid program as a condition of having federal funds being made available to the states for our drugs under Medicaid and under Part B of the Medicare program.

Federal law requires that any company that participates in the Medicaid Drug Rebate Program also participate in the Public Health Service’s 340B drug pricing program in order for federal funds to be available for the manufacturer’s drugs under

Medicaid and Medicare Part B. The 340B program requires participating manufacturers to agree to charge statutorily-defined covered entities no more than the 340B “ceiling price” for the manufacturer’s covered outpatient drugs. These 340B covered entities include a variety of community health clinics and other entities that receive health services grants from the Public Health Service, as well as hospitals that serve a disproportionate share of low-income patients.

Medicare is a federal program that is administered by the federal government that covers individuals age 65 and over or that are disabled as well as those with certain health conditions. Medicare Part B generally covers drugs that must be administered by physicians or other health care practitioners; among others. Medicare Part B generally pays for such drugs under a payment methodology based on the average sales price of the drugs. Manufacturers are required to report average sales price information to CMS on a quarterly basis. Manufacturers that fail to pay refunds could be subject to civil monetary penalties of 125 percent of the refund amount. Failure to timely pay a Part B inflation rebate is subject to a civil monetary penalty.

Medicare Part D generally provides coverage to enrolled Medicare patients for self-administered drugs (i.e., drugs that are not administered by a physician). The prescription drug plans negotiate pricing with manufacturers and pharmacies, and may condition formulary placement on the availability of manufacturer discounts. In addition, under the new manufacturer discount program established by the IRA and effective in 2025, manufacturers are, in general, required to provide a 10% discount on a covered Part D drug where a beneficiary is in the initial phase of Part D coverage and a 20% discount where a beneficiary is in the catastrophic phase of Part D coverage. Failure to timely pay a Part D inflation rebate is subject to a civil monetary penalty.

This or any other legislative change could impact the market conditions for our product candidates.

In addition, in order to be eligible to have its products paid for with federal funds under the Medicaid and Medicare Part B programs and purchased by the Department of Veterans Affairs (the VA), Department of Defense (DoD), Public Health Service, and Coast Guard (the Big Four Agencies) and certain federal grantees, a manufacturer also must participate in the VA Federal Supply Schedule (FSS) pricing program, established by Section 603 of the Veterans Health Care Act of 1992 (the VHCA). Under this program, the manufacturer is obligated to make its covered drugs (innovator multiple source drugs, single source drugs, and biologics) available for procurement on an FSS contract and charge a price to the Big Four Agencies that is no higher than the Federal Ceiling Price (FCP), which is a price calculated pursuant to a statutory formula. The FCP is derived from a calculated price point called the “non-federal average manufacturer price” (Non-FAMP), which we will be required to calculate and report to the VA on a quarterly and annual basis. Moreover, pursuant to Defense Health Agency (DHA) regulations, manufacturers must provide rebates on utilization of their innovator and single source products that are dispensed to TRICARE beneficiaries by TRICARE network retail pharmacies. The formula for determining the rebate is established in the regulations and is based on the difference between the annual non-federal average manufacturer price and the Federal Ceiling Price, each required to be calculated by us under the VHCA. The requirements under the Medicaid Drug Rebate Program, 340B program, FSS, and TRICARE programs could reduce the revenue we may generate from any products that are commercialized in the future and could adversely affect our business and operating results.

United States Healthcare Reform

The United States federal and state governments have enacted or proposed legislative and regulatory changes affecting the healthcare system that could prevent or delay marketing approval of our product candidates, restrict or regulate post-approval activities and affect our ability to profitably sell any product candidate for which we obtain marketing approval. The United States government, state legislatures and foreign governments also have shown significant interest in implementing cost-containment programs to limit the growth of government-paid healthcare costs, including price controls, restrictions on reimbursement and requirements for substitution of generic products for branded prescription drugs. For example, at the federal level, the government has shown substantial interest in taking a variety of measures aimed at lowering United States prescription drug prices to align with the lowest prices available for the same drugs in comparable developed nations (so called “most favored nation” pricing). At the state level, some legislatures have passed laws that regulate how manufacturers make the 340B Drug Pricing Program ceiling price available on the market. Additionally, some states have established Prescription Drug Affordability Boards (or similar entities) to review high-cost drugs and, in some cases, set upper payment limits.

In recent years, Congress has considered reductions in Medicare reimbursement levels for drugs administered by physicians. The Centers for Medicare & Medicaid Services (CMS), the agency that administers the Medicare and Medicaid programs, has authority to revise reimbursement rates and to implement coverage restrictions. Cost reduction initiatives and changes in coverage implemented through legislation or regulation could decrease utilization of and reimbursement for any approved products, which in turn would affect the price we can receive for those products. Any reduction in reimbursement from Medicare and other government programs may result in a similar reduction in payment from commercial payers. The implementation of cost containment measures or other healthcare reforms may prevent us from being able to generate revenue, attain operating profitability, or commercialize our products.

Certain provisions of the ACA have been subject to judicial challenges as well as efforts to modify them or to alter their interpretation and implementation. For example, the Tax Cuts and Jobs Act eliminated the tax-based shared responsibility payment for individuals who fail to maintain minimum essential coverage under section 5000A of the Internal Revenue Code of 1986, commonly referred to as the individual mandate. Additional legislative changes, regulatory changes, and judicial challenges related to the ACA remain possible. Any such changes could decrease the number of individuals with health coverage.

For example, the Budget Control Act of 2011, among other things, created the Joint Select Committee on Deficit Reduction to recommend to Congress proposals for spending reductions. The Joint Select Committee did not achieve a targeted deficit reduction, which triggered the legislation’s automatic reductions. In concert with subsequent legislation, this has resulted in aggregate reductions to Medicare payments to providers of, on average, 2% per fiscal year through 2032. Sequestration is currently set at 2%. As long as these cuts remain in effect, they could adversely impact payment for any of our products that are reimbursed under Medicare, once commercialized.

Further, the IRA, among other things, established a Medicare Part B and Part D inflation rebate scheme, under which, generally, manufacturers owe rebates if the average sales price of certain Part B drugs or annual average manufacturer price of certain covered Part D drugs increases faster than the pace of inflation. The IRA further makes several changes to the Medicare Part D benefit, including a limit on annual out-of-pocket costs, and replacement of the coverage gap discount program with a new manufacturer discount program beginning in 2025.

Additionally, on July 4, 2025, the “One Big Beautiful Bill Act” (the OBBBA) was signed into law. The OBBBA is projected to decrease federal health care spending by approximately $1 trillion by reducing Medicaid spending and enrollment and making

changes to federal Medicare spending. The law also made changes to ACA marketplace enrollment that are projected to decrease the number of individuals with marketplace coverage.

Any reduction in reimbursement from Medicare, Medicaid or other government programs may result in a similar reduction in payments from private payors. The implementation of cost containment measures or other healthcare reforms may prevent us from being able to generate revenue, attain operating profitability or commercialize our products.

Foreign Regulation

In addition to regulations in the United States, we will be subject to a number of significant regulations in other jurisdictions regarding research, clinical trials, approval, manufacturing, distribution, marketing and promotion, safety reporting, privacy and pricing and reimbursement.

Corporate Information

We, under the name Tekmira Pharmaceuticals Corporation (Tekmira), were incorporated pursuant to the British Columbia Business Corporations Act (BCBCA), on October 6, 2005, and commenced active business on April 30, 2007, when Tekmira and its parent company, Inex Pharmaceuticals Corporation (Inex), were reorganized under a statutory plan of arrangement (the Plan of Arrangement), completed under the provisions of the BCBCA. The Plan of Arrangement saw Inex’s entire business transferred to and continued by Tekmira.

On March 4, 2015, we completed a business combination pursuant to which OnCore Biopharma, Inc. became our wholly-owned subsidiary. Effective July 31, 2015, our corporate name changed from Tekmira Pharmaceuticals Corporation to Arbutus Biopharma Corporation. Also effective July 31, 2015, the corporate name of our wholly owned subsidiary, OnCore Biopharma, Inc. changed to Arbutus Biopharma, Inc. (Arbutus Inc.). We had two wholly owned subsidiaries: Arbutus Inc. (Protiva). Effective January 1, 2018, Protiva was amalgamated with Arbutus Inc. and we had one wholly-owned subsidiary as of December 31, 2025: Arbutus Inc.

Our current mailing address is 701 Veterans Circle, Warminster, Pennsylvania 18974, and our telephone number is (267) 469-0914. We maintain a website at www.arbutusbio.com.

Unless stated otherwise or the context otherwise requires, references herein to “Arbutus”, “we”, “us” and “our” refer to Arbutus Biopharma Corporation, and, unless the context requires otherwise, the subsidiaries through which we conduct business.

Investor Information

We are a reporting issuer in Canada under the securities laws of each of the Provinces of Canada. Our common shares trade on the Nasdaq Global Select Market under the symbol “ABUS”. We maintain a website at http://www.arbutusbio.com. The information on our website is not incorporated by reference into this Annual Report on Form 10-K and should not be considered to be a part of this Annual Report on Form 10-K. Our website address is included in this Annual Report on Form 10-K as an inactive technical reference only. Copies of this Annual Report on Form 10-K, and our other annual reports on Form 10-K, proxy statements, quarterly reports on Form 10-Q, current reports on Form 8-K and, if applicable, amendments to those reports filed or furnished pursuant to Section 13(a) or 15(d) of the Securities Exchange Act of 1934, as amended, are available free of charge through our website under “Investors – Financial Information – SEC Filings” as soon as reasonably practicable after we electronically file these materials with, or otherwise furnish them to, the SEC. The SEC maintains an Internet site that contains reports, proxy and information statements and other information regarding issuers that file electronically with the SEC at www.sec.gov.

Item 1A. Risk Factors

Our business is subject to substantial risks and uncertainties. The occurrence of any of the following risks and uncertainties, either alone or taken together, could materially and adversely affect our business, financial condition, results of operations or prospects. In these circumstances, the market price of our common shares could decline and you may lose all or part of your investment. The risks and uncertainties described below are not the only ones we face. Risks and uncertainties of general applicability and additional risks and uncertainties not currently known to us or that we currently deem to be immaterial may also materially and adversely affect our business, financial condition, results of operations or prospects.

Risks Related to Our Business, Our Financial Results and Need for Additional Capital

We are involved in patent infringement lawsuits to protect and assert our intellectual property rights against large, well-capitalized companies and the United States, which requires that we continue to expend substantial resources, and we may not be successful in these proceedings.

We are currently involved in a patent infringement lawsuit in the United States against Pfizer/BioNTech and, if filed by Moderna, the Moderna §1498 Appeal, which are actions against large, well-capitalized companies. We are also involved in a lawsuit 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. Some of these lawsuits have been ongoing for years and have required substantial investments of resources. We anticipate that these proceedings will continue to require similar investments over an extended period of time. Each of the proceedings is subject to substantial uncertainty regarding their outcomes, which is highly dependent upon specific factual matters and legal interpretations. We believe that it is critical to our future success to continue to pursue these actions, and we intend to do so. Moreover, the ruling or decision in one proceeding is not necessarily indicative of rulings or decisions that may be issued in another proceeding, even if the factual and legal matters are similar. We expect that various courts will issue significant rulings within the next year, and the disclosure of those rulings may cause substantial volatility in our share price and could impact our business, financial condition and results of operations.

We face risks associated with the Contingent Settlement Payment under the Moderna Settlement Agreement.

In addition to the aggregate $950.0 million Noncontingent Settlement Payment due to us and Genevant, the Moderna Settlement Agreement provides for a Contingent Settlement Payment of up to an aggregate $1.3 billion to us and Genevant, which is payable in full only upon the occurrence of an Arbutus/Genevant §1498 Victory (as defined above). If the appellate court determines that §1498 bars all or some of our and Genevant’s claims, we may receive no payment at all or only a prorated portion of the $1.3 billion Contingent Settlement Payment. While Moderna is subject to financial covenants under the Moderna Settlement Agreement to protect the payment of the Contingent Settlement Payment, there can be no assurance that we and Genevant will receive this payment in a timely manner, or at all, due to factors beyond our control, including, among others, the satisfaction of contractual conditions, administrative or procedural delays, or disputes regarding the interpretation or enforcement of the Moderna Settlement Agreement. Moreover, under certain circumstances specified in the Moderna Settlement Agreement, if an Arbutus/Genevant §1498 Victory is subsequently overturned in Moderna’s favor in a final, non‑appealable decision, we and Genevant would be required to return any Contingent Settlement Payment previously received, together with interest. Any obligation to repay such amounts could require us to use a significant portion of our available cash. Additionally, any Contingent Settlement Payment we do receive may be subject to financial covenants on us to protect the potential repayment of the Contingent Settlement Payment, which would restrict our ability to freely use those proceeds during that period. The Moderna §1498 Appeal and any subsequent related appeals are subject to substantial uncertainty regarding their outcomes, including the timing thereof, and there can be no assurance that an Arbutus/Genevant §1498 Victory will be achieved. For more information, see “Item 1 – Business – Other Collaborations, Royalty Entitlements and Intellectual Property Litigation” and “Item 3 – Legal Proceedings.”

Our expectation of receiving proceeds from the Moderna Settlement Agreement, including through the Genevant License and our equity ownership interest in Genevant, may not be realized. Any delay in receiving such payments, failure to receive some or all of the proceeds under the Moderna Settlement Agreement, or an obligation to return any Contingent Settlement Payments

previously received could materially adversely affect our liquidity, financial condition, results of operations, and ability to execute our business strategy.

We are in the early stages of our development, and there is a limited amount of information about us upon which you can evaluate our product candidates.

We have not begun to market or generate revenues from the commercialization of any of our product candidates. For example, to continue the development of our cHBV programs, we would need to successfully:

•execute development activities using technologies involved in the development of our product candidates;

•build, maintain and protect a strong intellectual property portfolio;

•gain regulatory approval and market acceptance for the commercialization of any product candidates we develop;

•conduct sales and marketing activities if any of our product candidates are approved;

•develop and maintain successful strategic relationships; and

•manage our spending and cash requirements to support our clinical trials, regulatory approvals, commercialization and the maintaining of our intellectual property portfolio.

If we are unsuccessful in accomplishing these objectives, we may not be able to develop our product candidates, raise capital, expand our business or continue our operations.

We are concentrating and intend to continue to concentrate our internal development efforts primarily on the development of product candidates targeting cHBV infection. Our future success depends in part on the successful development of these product candidates. Our approach to the treatment of HBV is unproven, and we do not know whether we will be able to develop any products of commercial value.

There is no known functional cure for HBV. Any compounds that we develop may not effectively address HBV persistence. Even if we are able to develop compounds that address one or more of the key factors in the HBV life cycle (e.g., HBV replication, HBsAg expression and immune reactivation), targeting these key factors has not been proven to functionally cure HBV.

Additional funds may be dilutive to shareholders or impose operational restrictions.

Our principal sources of liquidity are cash, cash equivalents and investments in marketable securities, which were $91.5 million as of December 31, 2025. While we do expect payments pursuant to the Moderna Settlement Agreement, we may be restricted from freely using the Contingent Settlement Payment while subject to repayment, and we are evaluating a return of capital to shareholders and may not retain all or part of the Noncontingent Settlement Payment. In particular, our funding needs may vary depending on a number of factors including:

•costs associated with prosecuting and enforcing our patent claims and other intellectual property rights, including our ongoing patent infringement matter against Pfizer/BioNTech, the Moderna §1498 Appeal (if filed by Moderna), and our lawsuit against the United States;

•a potential return of capital to our shareholders in connection with proceeds from the Moderna Settlement Agreement;

•revenues earned from our licensing partners, including Alnylam and Acuitas;

•the extent to which we continue the development of our product candidates or form licensing arrangements to advance our product candidates;

•our decisions to in-license or acquire additional products, additional product candidates or technology for development;

•our ability to attract and retain development or commercialization partners, and their effectiveness in carrying out the development and ultimate commercialization of one or more of our product candidates;

•whether batches of product candidates that we manufacture fail to meet specifications resulting in clinical trial delays and investigational and remanufacturing costs;

•the decisions, and the timing of decisions, made by health regulatory agencies regarding our technology and product candidates; and

•competing products, product candidates and technological and market developments.

There can be no assurance that we will be able to complete any such transaction on acceptable terms or otherwise.

In addition, we may issue equity as part of the consideration to our licensors, to compensate consultants or to settle outstanding payables, all of which could cause our shareholders to experience additional dilution in net book value per share. Any such additional equity securities may have rights, preferences and privileges senior to those of the holders of our common shares.

Debt financing, if available, will result in increased fixed payment obligations and may involve agreements that include covenants limiting or restricting our ability to take specific actions, such as incurring additional debt, making capital expenditures or declaring dividends. Any debt financing or additional equity that we raise may contain terms, such as liquidation and other preferences, which are not favorable to us or our existing shareholders. If we raise additional funds through corporate collaborations, partnerships or other strategic transactions, it may be necessary to relinquish valuable rights to our product candidates, our technologies or future revenue streams or to grant licenses or sell assets on terms that may not be favorable to us.

If we are unable to raise additional capital in sufficient amounts or on terms acceptable to us, we will need to curtail and reduce our operations and costs, and modify our business strategy which may require us to, among other things:

•significantly delay, scale back or discontinue the development or commercialization of one or more of our product candidates;

•seek collaborators for one or more of our product candidates at an earlier stage than otherwise would be desirable or on terms that are less favorable than might otherwise be available;

•sell or license on unfavorable terms our rights to one or more of our technologies or product candidates that we otherwise would seek to develop or commercialize ourselves; or

•seek a sale of the Company or cease operations.

To date, we have had no product revenues.

With the exception of the years ended December 31, 2006 and December 31, 2012, we have incurred losses each fiscal year since inception through the year ended December 31, 2025 and have not received any revenues other than from research and development collaborations, royalties, license fees and milestone payments. From inception to December 31, 2025, we have an accumulated net deficit of approximately $1.4 billion. Investment in drug development is highly speculative because it entails substantial upfront capital expenditures and significant risk that a product candidate will fail to gain regulatory approval or become commercially viable.

We expect to continue to incur significant expenses and operating losses for the foreseeable future. We anticipate that our expenses will continue to be significant if and as we:

•continue the clinical development of our products candidates;

•initiate additional clinical trials or other studies or trials for our product candidates;

•continue or expand our licensing arrangements with our licensing partners;

•change or add additional manufacturers or suppliers;

•seek regulatory approvals for our product candidates that successfully complete clinical trials;

•establish a sales, marketing and distribution infrastructure to commercialize any product candidates for which we may obtain regulatory approval;

•acquire or in-license other product candidates and technologies;

•maintain, protect and expand our intellectual property portfolio;

•attract and retain skilled personnel;

•create additional infrastructure to support our product development and planned future commercialization efforts; and

•experience any delays or encounter issues with any of the above.

The operating losses we incur may fluctuate significantly from quarter to quarter and year to year, such that a period-to-period comparison of our results of operations may not be a good indication of our future performance.

We do not generate revenues from product sales and may never be profitable from operations.

We do not anticipate generating significant revenues from product sales for the foreseeable future, if ever. Our ability to generate future revenues from product sales depends heavily on our success in:

•completing clinical development of our product candidates;

•seeking and obtaining regulatory approvals for product candidates for which we complete clinical trials;

•developing a sustainable, scalable, reproducible, and transferable manufacturing process for our product candidates;

•establishing and maintaining supply and manufacturing relationships with third parties that can provide adequate (in amount and quality) products and services to support clinical development and the market demand for our product candidates for which we obtain regulatory approval;

•launching and commercializing product candidates for which we obtain regulatory approval, either by collaborating with partners or, if launched independently, by establishing a sales force, marketing, sales operations and distribution infrastructure;

•obtaining market acceptance of our product candidates for which we obtain regulatory approval as viable treatment options;

•addressing any competing technological and market developments;

•implementing additional internal systems and infrastructure, as needed;

•identifying and validating new product candidates;

•negotiating favorable terms in any collaboration, licensing or other arrangements into which we may enter;

•maintaining, protecting and expanding our portfolio of intellectual property rights, including patents, trade secrets and know-how; and

•attracting, hiring and retaining qualified personnel.

Even if one or more of the product candidates that we develop is approved for commercial sale, we anticipate incurring significant costs associated with commercializing any approved product candidate. Our expenses could increase beyond expectations if we are required by the FDA or other regulatory authorities outside the United States to perform clinical trials or other studies in addition to those that we currently anticipate.

Risks Related to Development, Clinical Testing, Regulatory Approval, Marketing, and Coverage and Reimbursement of our Product Candidates

Our product candidates are in early stages of development and must go through clinical trials, which are very expensive, time-consuming and difficult to design and implement. The outcomes of clinical trials are uncertain, and delays in the completion of or the termination of any clinical trial of our product candidates could harm our business, financial condition and prospects.

Our development programs are at an early stage of development. We must demonstrate our product candidates’ safety and efficacy in humans through extensive clinical testing, which is expensive and time-consuming and requires specialized knowledge and expertise.

Clinical trials are also expensive and difficult to design and implement, in part because they are subject to rigorous regulatory requirements. The clinical trial process is also time-consuming, and the outcome is not certain. We estimate that clinical trials of our product candidates will take multiple years to complete. Failure can occur at any stage of a clinical trial, and we could encounter problems that cause us to abandon or repeat clinical trials. The commencement and completion of clinical trials may be delayed or precluded by a number of factors, including:

•the results of the review of our pipeline and development plans for our hepatitis B programs;

•delay or failure in reaching agreement with the FDA or other regulatory authorities outside the United States on the design of a given trial, or in obtaining authorization to commence a trial;

•delay or failure in reaching agreement on acceptable terms with prospective CROs and clinical trial sites;

•delay or failure in obtaining approval of an IRB or ethics committees before a clinical trial can be initiated at a given site;

•withdrawal of clinical trial sites from our clinical trials, including as a result of changing standards of care or the ineligibility of a site to participate;

•delay or failure in recruiting and enrolling subjects in our clinical trials;

•delay or failure in having subjects complete a clinical trial or return for post-treatment follow up;

•clinical sites or investigators deviating from trial protocol, failing to conduct the trial in accordance with applicable regulatory requirements, or dropping out of a trial;

•inability to identify and maintain a sufficient number of trial sites;

•failure of CROs to meet their contractual obligations or deadlines;

•the need to modify a trial protocol;

•unforeseen safety issues;

•emergence of dosing issues;

•lack of effectiveness data during clinical trials;

•changes in the standard of care of the indication being studied;

•reliance on third-party suppliers for the clinical trial supply of product candidates and failure by our third-party suppliers to comply with regulatory requirements or meet their contractual obligations to us in a timely manner, or at all;

•inability to monitor subjects adequately during or after treatment;

•limitations on our or our CROs’ ability to access and verify clinical trial data captured at clinical trial sites through monitoring and source document verification;

•lack of sufficient funding to finance the clinical trials; and

•changes in governmental regulations or administrative action.

We, the FDA, other regulatory authorities outside the United States, or an IRB may suspend a clinical trial at any time for various reasons, including if it appears that the clinical trial is exposing participants to unacceptable health risks or if the FDA or one or more other regulatory authorities outside the United States find deficiencies in our IND or similar application outside the United States or the conduct of the trial. If we experience delays in the completion of, or the termination of, any clinical trial of any of our product candidates, the commercial prospects of such product candidate will be harmed, and our ability to generate product revenues from such product candidate will be delayed or rendered impossible. In addition, any delays in completing our clinical trials will increase our costs, slow down our product candidate development and approval process, and jeopardize our ability to commence product sales and generate revenues.

Even if our clinical trials are successfully completed as planned, the results may not support approval of our product candidates under the laws and regulations of the FDA or other regulatory authorities outside the United States. The clinical trial process may fail to demonstrate that our product candidates are both safe and effective for their intended uses. Preclinical and clinical data and analyses are often able to be interpreted in different ways. Even if we view our results favorably, if a regulatory authority has a different view, we may still fail to obtain regulatory approval of our product candidates.

Any of these occurrences may harm our business, financial condition, results of operations, cash flows and prospects significantly.

Preclinical studies and preliminary and interim data from clinical trials of our product candidates are not necessarily predictive of the results or success of ongoing or later clinical trials of our product candidates. If we cannot replicate the results from our preclinical studies and initial clinical trials of our product candidates in later clinical trials, we may be unable to successfully develop, obtain regulatory approval for and commercialize our product candidates.

Preclinical studies and any positive preliminary and interim data from our clinical trials of our product candidates may not necessarily be predictive of the results of ongoing or later clinical trials. A number of companies in the pharmaceutical and biotechnology industries, including us and many other companies with greater resources and experience than we, have suffered significant setbacks in clinical trials, even after seeing promising results in prior preclinical studies and clinical trials. Even if we are able to complete our planned clinical trials of our product candidates according to our current development timeline, initial positive results from preclinical studies and clinical trials of our product candidates may not be replicated in subsequent clinical trials. The design of our later stage clinical trials could differ in significant ways (e.g., inclusion and exclusion criteria, endpoints, statistical analysis plan) from our earlier stage clinical trials, which could cause the outcomes of the later stage trials to differ from those of our earlier stage clinical trials. If we fail to produce positive results in our planned clinical trials of any of our product candidates, the development timeline and regulatory approval and commercialization prospects for our product candidates, and, correspondingly, our business and financial prospects, would be materially adversely affected.

Because we have limited operational resources, we may decide to pursue a particular product candidate and fail to advance product candidates that later demonstrate a greater chance of clinical and commercial success.

We are a development stage company with limited operational resources and revenues. Because of this, we must make strategic decisions regarding resource allocations and which product candidates to pursue. There can be no assurance that we will be able to develop all potentially promising product candidates that we may identify. Based on preliminary results, we may choose to advance a particular product candidate that later fails to be successful, and simultaneously forgo or defer further investment in other product candidates that later are discovered to demonstrate greater promise in terms of clinical and commercial success. If we make resource allocation decisions that later are shown to be inaccurate, our business and prospects could be harmed.

We are currently conducting a clinical trial at least partially outside the United States and we may conduct further clinical trials outside the United States in the future. We are currently conducting our clinical trial in the United States, Moldova, Taiwan, South Korea, and Hong Kong. Although the FDA may accept data from clinical trials conducted outside the United States that are not conducted under an IND, the FDA’s acceptance of these data is subject to certain conditions. The data must be applicable to the United States population and United States medical practice in ways that the FDA deems clinically meaningful. The FDA also must have the ability to validate the foreign data through an on-site inspection or other appropriate means in the event the FDA considers such on-site inspection to be necessary. In addition, while these clinical trials are subject to the applicable local laws, FDA acceptance of the data will be dependent upon its ability to verify the data and its determination that the trials complied with all applicable United States laws and regulations. We cannot assure you that the FDA will accept data from trials conducted outside of the United States that are not conducted under an IND. If the FDA does not accept the data from such clinical trials, we likely would need to conduct additional trials, which would be costly and time-consuming and could delay or permanently halt our development of our product candidates.

We cannot guarantee how long it will take regulatory agencies to review our applications for product candidates, and we may fail to obtain the necessary regulatory approvals to market our product candidates.

Before we can commercialize our product candidates in the United States, we must obtain approval from the FDA. We must similarly obtain approvals from comparable regulatory authorities to commercialize our product candidates in jurisdictions outside the United States.

To obtain marketing approval, United States laws require:

•controlled research and human clinical testing that comply with GLP and GCP, as applicable;

•establishment of the safety and efficacy of the product for each use sought;

•government review and approval of a submission containing, among other things, manufacturing, preclinical and clinical data; and

•compliance with GMP regulations.

The process of reviewing and approving a drug is time-consuming, unpredictable, and dependent on a variety of factors outside of our control. The FDA and corresponding regulatory authorities in jurisdictions outside the United States have a significant amount of discretion in deciding whether or not to approve a marketing application. Our product candidates could fail to receive regulatory approval from the FDA or comparable regulatory authorities outside the United States for several reasons, including:

•disagreement with the design or implementation of our clinical trials;

•failure to demonstrate that our product candidates are safe and effective for the proposed indication;

•failure of clinical trial results to meet the level of statistical significance required for approval;

•failure to demonstrate that the product candidates’ benefits outweigh its’ risks;

•disagreement with our interpretation of preclinical or clinical data; and

•inadequacies in the manufacturing facilities or processes of third-party manufacturers.

The FDA or comparable regulatory authorities outside the United States may require us to conduct additional preclinical and clinical testing, which may delay or prevent approval of a product candidate and our commercialization plans, or cause us to abandon the development program. Further, any approval we receive may be for fewer or more limited indications than we request, may not include labeling claims necessary for successful commercialization of the product candidate, or may be contingent upon our conducting costly post-marketing studies. Any of these scenarios could materially harm the commercial prospects of a product candidate, and our operations will be adversely effected.

Disruptions at the FDA, including due to a reduction in the FDA’s workforce and/or inadequate funding for the FDA, could prevent the FDA from performing normal functions on which our business relies, which could negatively impact our business.

The ability of the FDA to review and approve new products or review other regulatory submissions can be affected by a variety of factors, including statutory, regulatory and policy changes, inadequate government budget and funding levels, a reduction in the FDA’s workforce and its ability to hire and retain key personnel. Disruptions at the FDA and other agencies may also increase the time to meet with and receive agency feedback, review and/or approve our submissions, conduct inspections, issue regulatory guidance, or take other actions that facilitate the development, approval and marketing of regulated products, which would adversely affect our business. In addition, government proposals to reduce or eliminate budgetary deficits may include reduced allocations to the FDA and other related government agencies. It is not entirely clear how actions by the presidential administration or other parts of the federal government have already impacted and will continue to impact the FDA or other regulatory authorities that oversee the product development portion of our business. These budgetary pressures may reduce the FDA’s ability to perform its responsibilities. If a significant reduction in the FDA’s workforce continues, the FDA’s budget is significantly reduced or another prolonged government shutdown occurs, it could significantly impact the ability of the FDA to timely review and process our regulatory submissions or take other actions critical to the development or marketing of our products, if approved, which could have a material adverse effect on our business.

If a particular product candidate causes undesirable side effects, then we may be unable to receive regulatory approval of or commercialize such product candidate.

We may experience numerous unforeseen events during, or as a result of, the testing process that could delay or prevent commercialization of any of our product candidates, including the occurrence of undesirable side effects. Such side effects could lead to clinical trial challenges, such as difficulties in subject recruitment, retention, and adherence, potential product

liability claims, and possible termination by health authorities. These types of clinical trial challenges could in turn, delay or prevent regulatory approval of our product candidate. Side effects may also lead regulatory authorities to require stronger product warnings on the product label, costly post-marketing studies, and/or a Risk Evaluation and Mitigation Strategy (REMS), among other possible requirements. If the product candidate has already been approved, such approval may be withdrawn. Any delay in, denial, or withdrawal of marketing approval for one of our product candidates will adversely affect our business, including our results of operations and financial position. Even if one or more of our product candidates receives marketing approval, undesirable side effects may limit such product’s commercial viability. Patients may not wish to use our product, physicians may not prescribe our product, and our reputation may suffer. Any of these events may significantly harm our business and financial prospects.

We may find it difficult to enroll patients in our clinical trials, which could delay or prevent clinical trials of our product candidates.

Identifying and qualifying patients to participate in clinical trials of our product candidates is critical to our success. The timing of our clinical trials depends in part on the speed at which we can recruit patients to participate in testing our product candidates.

We may not be able to identify, recruit and enroll a sufficient number of patients, or those with required or desired characteristics to achieve diversity in a clinical trial, or complete our clinical trials in a timely manner. Subject enrollment is affected by a variety of factors including, among others:

•severity of the disease under investigation;

•design of the trial protocol;

•prevalence of the disease/size of the patient population;

•eligibility criteria for the clinical trial in question;

•perceived risks and benefits of the product candidate under study;

•willingness or availability of patients to participate in the clinical trials;

•proximity and availability of clinical trial sites for prospective patients;

•ability to recruit clinical trial investigators with the appropriate competencies and experience;

•availability of competing therapies and clinical trials;

•efforts to facilitate timely enrollment in clinical trials;

•ability to obtain and maintain subject consents;

•patient referral practices of physicians;

•risk that patients enrolled in clinical trials will drop out of the trials before completion; and

•ability to monitor patients adequately during and after treatment.

If patients are unwilling to participate in our clinical trials, the timeline for recruiting patients, conducting clinical trials and obtaining regulatory approval of potential products may be delayed. These delays could result in increased costs, delays in advancing or testing our product candidates or termination of the clinical trials altogether.

It may take considerable time and expense to resolve the clinical hold that has been placed on our IND application of AB-101 by the FDA, and no assurance can be given that the FDA will remove the clinical hold, in which case our business and financial prospects may be adversely affected.

On April 25, 2023, we announced that we were notified via verbal communication from the FDA that our AB-101 IND application had been placed on clinical hold, meaning we must suspend any ongoing clinical investigation in the United States, may not recruit subjects to the clinical trial in the United States, and may not administer AB-101 to any subjects in the United States. For purposes of clarity, the Phase 1 clinical trial in the United States had not been initiated and we had not dosed any patients with AB-101. In May 2023, we received the clinical hold letter from the FDA, which raised questions about certain preclinical data and aspects of the clinical trial design. In July 2023, Medsafe approved our CTA application for a Phase 1 clinical trial in New Zealand for AB-101; however, there are no assurances that FDA will accept the results of such clinical trial and may require us to conduct an additional Phase 1 clinical trial or additional nonclinical studies. If the FDA does not accept the results of our Phase 1 clinical trial in New Zealand for AB-101 or requires us to conduct additional trials or studies, it may take a considerable period of time, the length of which is not certain at this time, and expense for us to fully address the FDA’s

concerns. Even if we are able to fully respond to the FDA’s current concerns, the FDA may subsequently make additional requests that we would need to fulfill prior to the lifting of the clinical hold. It is possible that we will be unable to fully address the FDA’s concerns and, as a result, the clinical hold may never be lifted and we may never be able to initiate our AB-101 clinical program in the United States, which could have a material adverse effect on our business and financial prospects.

Even if our product candidates obtain regulatory approval, they will remain subject to ongoing regulatory requirements and oversight.

Approved drug products are subject to ongoing regulatory requirements and oversight, including requirements related to manufacturing, quality control, further development, labeling, packaging, storage, distribution, safety surveillance, import, export, advertising, promotion, recordkeeping and reporting. In addition, we will be subject to continued compliance with GMP and GCP requirements for any clinical trials that we conduct post-approval. If the FDA or a comparable regulatory authority outside the United States becomes aware of new safety information, it can impose additional restrictions on how the product is marketed or may seek to withdraw marketing approval altogether.

The ACA sometimes results in downward pressure on pharmaceutical reimbursement, which could negatively affect market acceptance of, and the price we may charge for, any products we develop that receives regulatory approval. Further, the IRA, among other things, established Medicare Part B and Part D inflation rebate schemes under which, generally, manufacturers owe rebates if the average sales price of certain Part B drugs, or the average manufacturer price of certain covered Part D drugs, increases faster than the pace of inflation, and a drug price negotiation program under which the prices for certain Medicare units of certain high Medicare spend drugs and biologics without generic or biosimilar competition are capped by reference to, among other things, a specified non-federal average manufacturer price, beginning in 2026. Also, the OBBBA is projected to decrease federal health care spending by approximately $1 trillion by reducing Medicaid spending and enrollment and making changes to federal Medicare spending. Additionally, individual states in the United States have passed legislation and implemented regulations designed to control pharmaceutical and biological product pricing, including sometimes regulating how manufacturers make the 340B Drug Pricing Program ceiling price available on the market and establishing Prescription Drug Affordability Boards (or similar entities) to review high-cost drugs and, in some cases, set upper payment limits and implementing marketing cost disclosure and transparency measures.

Coverage policies and third-party reimbursement rates may change at any time. Even if favorable coverage and reimbursement status is attained for one or more products for which we receive regulatory approval, less favorable coverage policies and reimbursement rates may be adopted in the future.

We face significant competition from other biotechnology and pharmaceutical companies targeting HBV.

As a significant unmet medical need exists for HBV, there are several large and small pharmaceutical companies focused on delivering therapeutics for treatment of HBV. These companies include, but are not limited to GSK plc, Gilead Sciences, Inc., Assembly Biosciences, Inc., Aligos Therapeutics, Inc., AusperBio Therapeutics, Inc., Brii Biosciences Limited, Mirum Pharmaceuticals, Inc., and Precision Biosciences, Inc. Further, in addition to current investigational therapeutics in development, it is likely that additional drugs will become available in the future for the treatment of HBV.

Many of our existing or potential competitors have substantially greater financial, technical and human resources than we do and significantly greater experience in the discovery and development of product candidates, as well as in obtaining regulatory approvals of those product candidates in the United States and other countries. Many of our current and potential future competitors also have significantly more experience commercializing drugs that have been approved for marketing.

We anticipate significant competition in the HBV market, with several early and late phase product candidates announced. Competition may increase further as a result of advances in the commercial applicability of technologies and greater availability of capital for investment in these industries. Our competitors may succeed in developing, acquiring or licensing, on an exclusive basis, product candidates that are more effective or less costly than any product candidate that we may develop.

If we successfully develop product candidates, and obtain approval for them, we will face competition based on many different factors, including the following:

•safety and effectiveness of our products;

•ease with which our products can be administered and the extent to which patients and physicians accept new routes of administration;

•timing and scope of regulatory approvals for these products;

•availability and cost of manufacturing, marketing and sales capabilities;

•price;

•reimbursement coverage; and

•patent position and regulatory exclusivities.

Our competitors may develop or commercialize products with significant advantages over any products we develop based on any of the factors listed above, or on other factors. Our competitors may therefore be more successful in commercializing their products than we are, which could adversely affect our competitive position and business. Competitive products may make any products we develop and commercialize obsolete or uncompetitive before we can recover the expenses of developing and commercializing such products. Such competitors could also recruit our employees, which could negatively impact our level of expertise and the ability to execute on our business plan.

Our ability to generate product revenues and become profitable from operations is largely dependent on the future commercial success of our HBV product candidates.

Market acceptance by physicians, patients and third-party payors of the products we may commercialize will depend on a number of factors, some of which are beyond our control, including:

•their efficacy, safety and other potential advantages in relation to alternative treatments;

•their relative convenience and ease of administration in relation to alternative treatments;

•the availability of adequate coverage or reimbursement by third parties, such as insurance companies and other healthcare payors, and by government healthcare programs, including Medicare and Medicaid;

•the prevalence and severity of adverse events;

•their cost of treatment in relation to alternative treatments, including generic products;

•the extent and strength of our third-party manufacturer and supplier support;

•the extent and strength of marketing and distribution support;

•the limitations or warnings contained in a product’s approved labeling; and

•distribution and use restrictions imposed by the FDA or other regulatory authorities outside the United States or that are part of a REMS or voluntary risk management plan.

We may incur substantial liabilities and may be required to limit commercialization of our products in response to product liability lawsuits.

The testing and marketing of medical products entail an inherent risk of product liability. Product liability claims may be brought against us by patients, healthcare providers or others using, administering or selling our products. Large judgments have been awarded in class action lawsuits based on drugs that had unanticipated side effects, which is an example of just one possible product liability claim that may be brought against us. If we cannot successfully defend ourselves against product liability claims, we may incur substantial liabilities or be required to limit commercialization of our products. Our inability to obtain sufficient product liability insurance at an acceptable cost to protect against potential product liability claims could prevent or inhibit the commercialization of products we develop, alone or with partners. Although we currently have product liability insurance coverage for our clinical trials for expenses or losses, our insurance coverage is limited to $10 million per occurrence, and $10 million in the aggregate, and may not reimburse us or may not be sufficient to reimburse us for any or all expenses or losses we may suffer. Moreover, insurance coverage is becoming increasingly expensive and, in the future, we may not be able to maintain insurance coverage at a reasonable cost or in sufficient amounts to protect us against losses due to liability. We intend to expand our insurance coverage to include the sale of commercial products if we obtain marketing approval for our product candidates in development, but we may be unable to obtain commercially reasonable product liability insurance for any products approved for marketing. Further, even if our agreements with any current or future partners entitle us to indemnification against losses, such indemnification may not be available or adequate should any claims arise. A successful product liability claim or series of claims brought against us could cause our share price to fall and, if judgments exceed our insurance coverage, could decrease our cash and adversely affect our business.

Coverage and adequate reimbursement may not be available for our product candidates, which could make it difficult for us to sell our products profitably.

Market acceptance and sales of any products that we develop and receive approval for will depend in part on the extent to which reimbursement for these products and related treatments will be available from third-party payors, including government health administration authorities and private health insurers. However, decisions regarding the extent of coverage and amount of reimbursement to be provided for each of our products will be made on a plan by plan basis. One payor’s determination to provide coverage for a product does not assure that other payors will also provide coverage, and adequate reimbursement, for the product. Each plan determines whether or not it will provide coverage for a drug, what amount it will pay the manufacturer for the drug, and on what tier of its formulary the drug will be placed. The position of a drug on a formulary generally determines the copayment that a patient will need to make to obtain the drug and can strongly influence the adoption of a drug by patients and physicians. Patients who are prescribed treatments for their conditions and providers performing the prescribed services generally rely on third-party payors to reimburse all or part of the associated healthcare costs. Patients are unlikely to use our products unless coverage is provided and reimbursement is adequate to cover a significant portion of the cost of our products.

We cannot be sure that coverage and reimbursement will be available for any product that we commercialize and, if reimbursement is available, what the level of reimbursement will be. Inadequate coverage and reimbursement may impact the demand for, or the price of, any

product for which we obtain marketing approval. If coverage and adequate reimbursement is not available, or is available only to limited levels, we may not be able to successfully commercialize any product candidates that we develop.

Additionally, there have been a number of legislative and regulatory proposals to change the healthcare system in the United States and in some jurisdictions outside the United States that could affect our ability to sell any future products profitably. These legislative and regulatory changes may negatively impact the reimbursement for any future products, following approval.

Healthcare providers, physicians and others will play a primary role in the recommendation and prescription of any products for which we obtain marketing approval. Restrictions under applicable United States federal and state healthcare laws and regulations are described in further detail in the section entitled Government Regulation – Post-Approval Regulation and include the following:

•the United States federal Anti-Kickback Law prohibits persons from, among other things, knowingly and willfully soliciting, offering, receiving or providing remuneration, directly or indirectly, in cash or in kind, to induce or reward, or in return for, the referral of an individual for the furnishing or arranging for the furnishing, or the purchase, lease or order, or arranging for or recommending purchase, lease or order, any good or service for which payment may be made under a federal healthcare program such as Medicare and Medicaid;

•the United States federal civil False Claims Act imposes civil penalties, sometimes pursued through whistleblower or qui tam actions, against individuals or entities for, among other things, knowingly presenting, or causing to be presented claims for payment of government funds that are false or fraudulent or making a false statement material to an obligation to pay money to the government, or knowingly concealing or knowingly and improperly avoiding, decreasing, or concealing an obligation to pay money to the federal government;

•HIPAA imposes criminal liability for knowingly and willfully executing a scheme to defraud any healthcare benefit program, knowingly and willfully falsifying, concealing or covering up a material fact or making any materially false, fictitious or fraudulent statement or representation, or making or using any false writing or document knowing the same to contain any materially false fictitious or fraudulent statement or entry, in connection with the delivery of or payment for healthcare benefits, items or services;

•HIPAA and its implementing regulations also impose obligations on certain covered entity health care providers, health plans and health care clearinghouses as well as their business associates (e.g., persons or entities that create, receive, maintain, or transmit protected health information in connection with providing a specified service or performing a function on behalf of a covered entity). We may obtain health information from third parties (including research institutions from which we obtain clinical trial data) that are subject to privacy and security requirements under HIPAA. Although we are not directly subject to HIPAA, other than with respect to providing certain employee benefits, we could potentially be subject to criminal penalties if we, our affiliates, or our agents knowingly receive individually identifiable health information maintained by a HIPAA-covered entity in a manner that is not authorized or permitted by HIPAA, and could potentially be subject to other civil and/or criminal penalties if we obtain, use, or disclose information in a manner not permitted by other privacy and data security and consumer protection laws;

•numerous federal and state laws and regulations that address privacy and data security, including state data breach notifications laws, state health information and/or genetic privacy laws, artificial intelligence laws passed in the United States, and federal and state consumer protection laws (e.g., Section 5 of the FTC Act, and the Health Breach Notification Rule, and the CCPA), govern the collection, use, disclosure and protection of health-related and other personal information, many of which differ from each other in significant ways, thus complicating the compliance

efforts. Compliance with these laws is difficult, constantly evolving, and time-consuming, and companies that do not comply with these laws may face government enforcement actions, civil and/or criminal penalties, or private action, as well as adverse publicity that could negatively affect our operating results and business;

•activities outside of the United States implicate local and national data protection standards, impose additional compliance requirements and generate additional risks of enforcement for non-compliance. The GDPR and other data protection, privacy and similar national, state/provincial and local laws, including the EU AI Act, may restrict the access, use, storage, disclosure or other processing activities concerning patient health information abroad. Compliance efforts will likely be an increasing and substantial cost in the future. Compliance efforts will likely be an increasing and substantial cost in the future;

•the United States federal Physician Payment Sunshine Act, being implemented as the Open Payments Program, requires manufacturers of drugs, devices, biologics, and medical supplies for which payment is available under Medicare, Medicaid or the Children’s Health Insurance Program (with certain exceptions) to report annually to CMS information related to direct or indirect payments and other transfers of value to physicians, certain other practitioners, and teaching hospitals, as well as ownership and investment interests held in the company by physicians and their immediate family members;

•price reporting requirements under the Medicaid Drug Rebate Program and the 340B Program and with respect to average sales price reporting under the Medicare Part B program, and rebate or discount liability under the Medicaid Drug Rebate Program, the 340B Program, and Medicare Part D, with respect to which we could be subject to civil monetary penalties for a failure to comply with our reporting or rebate or discount obligations, or termination from the Medicaid Drug Rebate Program or 340B program, which, in turn, could jeopardize the availability of federal funds for our products under Medicaid and Medicare Part B;

•the IRA, which, among other things, requires the United States Secretary of Health and Human Services to negotiate, with respect to Medicare units and subject to a specified cap, the price of a set number of certain high Medicare spend drugs and biologicals per year starting in 2026, penalizes manufacturers of certain Medicare Parts B and D drugs for price increases above inflation, and makes several changes to the Medicare Part D benefit, including a limit on annual out-of-pocket costs, and a change in manufacturer liability under the program which could negatively affect our business and financial condition; and

•analogous state laws and laws and regulations outside the United States, such as state anti-kickback and false claims laws, which may apply to sales or marketing arrangements and claims involving healthcare items or services reimbursed by non-governmental third-party payors, including private insurers; state laws and laws outside the United States that require pharmaceutical companies to comply with the pharmaceutical industry’s voluntary compliance guidelines and the relevant compliance guidance promulgated by the federal government or otherwise restrict payments that may be made to certain healthcare providers; state laws and laws outside the United States that require drug manufacturers to report information related to clinical trials, or information related to payments and other transfers of value to physicians and other healthcare providers or marketing expenditures; state laws that restrict the ability of manufacturers to offer co-pay support to patients for certain prescription drugs; and state laws and local ordinances that require identification or licensing of sales representatives.

Efforts to ensure that our collaborations with third parties, and our business generally, will comply with applicable United States and Canadian healthcare laws and regulations will involve substantial costs. It is possible that governmental authorities will conclude that our business practices may not comply with current or future statutes, regulations or case law involving applicable fraud and abuse or other healthcare laws and regulations. If any of the physicians or other providers or entities with whom we expect to do business is found not to be in compliance with applicable laws, they may be subject to criminal, civil or administrative sanctions, including exclusions from government funded healthcare

programs.

If we participate in the Medicaid Drug Rebate Program and other governmental pricing programs, failure to comply with obligations under these programs could result in additional reimbursement requirements, penalties, sanctions and fines, which could have a material adverse effect on our business, financial condition, results of operations and growth prospects.

Those rebates are based on pricing data reported by the manufacturer on a monthly and quarterly basis to CMS. These data include the average manufacturer price and, in the case of innovator products, the best price for each drug, which, in general, represents the lowest price available from the manufacturer to any wholesaler, retailer, provider, health maintenance organization, nonprofit entity, or governmental entity in the United States in any pricing structure, calculated to include all sales and associated rebates, discounts, and other price concessions. If we fail to pay the required rebate amount or report pricing data on a timely basis, we may be subject to civil monetary penalties and/or termination from the Medicaid Drug Rebate program. Additionally, civil monetary penalties can be applied if we are found to have knowingly submitted any false price or product information to the government, if we fail to submit the required price data on a timely basis, or if we misclassify or misreport product information. CMS could also decide to terminate any Medicaid drug rebate agreement, in which case federal payments may not be available under Medicaid or Medicare Part B for our covered outpatient drugs, if commercialized.

The ACA made significant changes to the Medicaid Drug Rebate Program, and CMS issued a final regulation to implement the changes to the Medicaid Drug Rebate Program under the ACA. CMS also issued a final regulation that modified prior Medicaid Drug Rebate Program regulations to permit reporting multiple best price figures with regard to value-based purchasing arrangements; and provide definitions for “line extension,” “new formulation,” and related terms, with the practical effect of expanding the scope of drugs considered to be line extensions that are subject to an alternative rebate formula. While the regulatory provisions that purported to affect the applicability of the best price and average manufacturer price exclusions of manufacturer-sponsored patient benefit programs, in the context of pharmacy benefit manager (PBM) “accumulator” programs were invalidated by a court, such programs (including copayment “maximizer” programs) may continue to negatively affect us in other ways. Our failure to comply with these price reporting and rebate payment obligations could negatively impact our financial results.

Federal law requires that a manufacturer also participate in the 340B Drug Pricing program in order for federal funds to be available for the manufacturer’s drugs under Medicaid and Medicare Part B. The 340B program requires participating manufacturers to agree to charge no more than the 340B “ceiling price” for the manufacturer’s covered outpatient drugs to specified “covered entities,” including community health centers and other entities that receive certain federal grants, as well as hospitals that serve a disproportionate share of low-income patients. The 340B ceiling price is calculated using a statutory formula, which is based on the average manufacturer price and rebate amount for the covered outpatient drug as calculated under the Medicaid Drug Rebate Program. If we are found to have knowingly and intentionally charged 340B covered entities more than the statutorily mandated ceiling price for any of our commercialized products, we could be subject to significant civil monetary penalties and/or such failure also could be grounds for the Health Resources and Services Administration (HRSA) to terminate our agreement to participate in the 340B program, in which case our covered outpatient drugs, once commercialized, would no longer be eligible for federal payment under the Medicaid or Medicare Part B program.

Further, the IRA established a Medicare Part B and Part D inflation rebate scheme and a drug price negotiation program, with the first negotiated prices taking effect in 2026. It also made several changes to the Medicare Part D benefit, including the creation of a new manufacturer discount program in place of the current coverage gap discount program (beginning in 2025). Manufacturers may be subject to civil monetary penalties for certain violations of the negotiation and inflation rebate provisions and an excise tax during a noncompliance period under the negotiation program. Drug manufacturers may also be subject to civil monetary penalties with respect to their compliance with the new Part D manufacturer drug discount program.

Pricing and rebate calculations are complex, vary across products and programs, and are often subject to interpretation by the manufacturer, governmental agencies, and courts. A manufacturer that becomes aware that its Medicaid reporting for a prior quarter was incorrect, or has changed as a result of recalculation of the pricing data, is obligated to resubmit corrected data up to

three years after those data originally were due. Restatements and recalculations increase the costs for complying with the laws and policies governing the Medicaid Drug Rebate program and could result in an overage or underage in our rebate liability for past quarters. They also may affect the 340B ceiling price and therefore liability under the 340B program.

Finally, in order to be eligible to have its products paid for with federal funds under the Medicaid and Medicare Part B programs and purchased by the Big Four Agencies and certain federal grantees, a manufacturer is required to participate in the FSS pricing program, established under Section 603 of the Veterans Health Care Act of 1992. Under this program, the manufacturer is obligated to make its covered drugs available for procurement on an FSS contract and charge a price to the Big Four Agencies that is no higher than the FCP, which is a price calculated pursuant to a statutory formula. Pursuant to applicable law, knowing provision of false information in connection with a Non-FAMP filing can subject a manufacturer to significant penalties for each item of false information. The FSS contract also contains extensive disclosure and certification requirements. If we overcharge the government in connection with the FSS contract or Tricare Retail Pharmacy Rebate Program, whether due to a misstated FCP or otherwise, we will be required to refund the difference to the government. Failure to make necessary disclosures and/or to identify contract overcharges can result in allegations against us under the False Claims Act and other laws and regulations. Unexpected refunds to the government, and any response to government investigation or enforcement action, would be expensive and time-consuming, and could have a material adverse effect on our business, financial condition, results of operations and growth prospects.

Under Section 703 of the National Defense Authorization Act for FY 2008, the manufacturer is required to pay quarterly rebates to DoD on utilization of its innovator products that are dispensed through DoD’s Tricare network pharmacies to Tricare beneficiaries. The rebates are calculated as the difference between the annual Non-FAMP and FCP for the calendar year that the product was dispensed. A manufacturer that overcharges the government in connection with the FSS contract or Tricare Retail Pharmacy Rebate Program, whether due to a misstated FCP or otherwise, is required to refund the difference to the government. Failure to make necessary disclosures and/or to identify contract overcharges can result in allegations against us under the False Claims Act and other laws and regulations.

We are subject to the FCPA, and potentially other applicable domestic or foreign anti-corruption or anti-bribery laws, which generally prohibit companies from engaging in bribery or other prohibited payments to foreign officials for the purpose of obtaining or retaining business and requires companies to maintain accurate books and records and internal controls, including at foreign-controlled subsidiaries.

Compliance with these anti-corruption laws and anti-bribery laws may be expensive and difficult, particularly in countries in which corruption is a recognized problem. In addition, these laws present particular challenges in the pharmaceutical industry, because, in many countries, hospitals are operated by the government, and physicians and other hospital employees are considered to be foreign officials. Certain payments to hospitals in connection with clinical trials and other work have been deemed to be improper payments to governmental officials and have led to FCPA enforcement actions.

We can make no assurance that our employees or other agents will not engage in prohibited conduct under our policies and procedures and anti-corruption laws and anti-bribery laws such as FCPA for which we might be held responsible. If our employees or other agents are found to have engaged in such practices, we could suffer severe penalties and other consequences that may have a material adverse effect on our business, financial condition and results of operations.

Risks Related to Our Dependence on Third Parties

We depend on our license agreement with Alnylam for the commercialization of ONPATTRO (Patisiran).

In 2012, we entered into a license agreement with Alnylam that entitles Alnylam to develop and commercialize products with our LNP technology. Alnylam received FDA approval in August 2018 and launched ONPATTRO immediately upon approval. We are entitled to low to mid-single-digit royalty payments escalating based on sales performance and received our first royalty

payment in the fourth quarter of 2018. In July 2019, we sold this royalty entitlement to OMERS, the defined benefit pension plan for municipal employees based in the Province of Ontario, Canada, effective as of January 1, 2019, for $20 million in gross proceeds before advisory fees. OMERS will retain this royalty 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. From the inception of the royalty sale through December 31, 2025, an aggregate of $26.5 million of royalties have been earned by OMERS. The possibility and timing of any possible reversion of the royalty entitlement is affected by many factors including:

•Alnylam’s and its distributors’ and sublicensees’ ability and actions to effectively market and sell ONPATTRO in each country where sold;

•the manner of sale, whether directly by Alnylam or by sublicensees or distributors, and the terms of sublicensing and distribution agreements;

•the amount and timing of sales of Alnylam in each country;

•regulatory approvals, appropriate labeling, and desirable pricing, insurance coverage and reimbursement;

•competition, including from Alnylam’s next generation RNAi product AMVUTTRA® (vutrisiran); and

•commencement of marketing in additional countries.

ONPATTRO sales have declined each of the last three years due primarily to sales from Alnylam’s next generation RNAi product AMVUTTRA cannibalizing sales of ONPATTRO. If Alnylam’s sales of ONPATTRO continue to decline, the royalty entitlement may never revert back to us.

We expect to depend in part on our licensing agreements for a significant portion of our revenues for the foreseeable future and to develop, conduct clinical trials with, obtain regulatory approvals for, and manufacture, market and sell some of our product candidates. If these licensing agreements are unsuccessful, or anticipated milestone or royalty payments are not received, our business could be materially adversely affected.

We may be unable to continue to establish such licensing agreements, and any licensing agreements we do establish may be unsuccessful, or we may not receive milestone payments or royalties as anticipated.

Should any licensing partner fail to develop or ultimately successfully commercialize any of the product candidates or technology to which it has obtained rights, our business may be adversely affected. In addition, once initiated, there can be no assurance that any of these licensing agreements will be continued or result in successfully commercialized products. Failure of a licensing partner to continue funding any particular program could delay or halt the development or commercialization of any products arising out of such program. In addition, there can be no assurance that the licensing partners will not pursue alternative technologies or develop alternative products either on their own or in collaboration with others, including our competitors.

Conflicts may arise with our licensing partners, including Alnylam, if they pursue alternative therapies for the diseases that we have targeted or develop or prioritize alternative products either on their own or in collaboration with others.

Additionally, conflicts may arise if there is a dispute about the progress of, or other activities related to, the clinical development of a product candidate, the achievement and payment of a milestone amount, the payment of royalties or the ownership of intellectual property that is developed during the course of a licensing agreement.

We rely on third parties to conduct our clinical trials, and if they fail to fulfill their obligations, perform services in a satisfactory manner, and/or comply with applicable legal or regulatory requirements, our development plans may be adversely affected.

We rely on independent clinical investigators, CROs and other third-party service providers to assist us in managing, monitoring and otherwise carrying out our clinical trials. We have contracted with, and we plan to continue to contract with, certain third parties to provide certain services, including site selection, enrollment, monitoring and data management. Although we depend heavily on these parties and have contractual agreements governing their activities, we do not control them and therefore, we cannot be assured that these third parties will adequately perform all of their contractual obligations to us. If our third-party service providers cannot adequately fulfill their obligations to us on a timely and satisfactory basis or if the quality or accuracy of our clinical trial data is compromised due to failure to adhere to our protocols or regulatory requirements or otherwise, or if such third parties otherwise fail to meet deadlines or follow legal or regulatory requirements, our development plans may be delayed or terminated.

Switching or adding additional third-party service providers involves additional cost and requires management time and focus. In addition, there is a natural transition period when a new third-party service provider begins work. As a result, delays may occur, which can materially impact our ability to meet our desired development timelines.

We rely exclusively on third parties to formulate and manufacture our product candidates, which exposes us to a number of risks that may delay development, regulatory approval and commercialization of our products or result in higher product costs.

We have limited experience in drug formulation or manufacturing, and we lack the resources and expertise to formulate or manufacture our own product candidates internally. Therefore, we rely on, and expect to continue to rely on, third-party expertise to support us in this area. We have entered into contracts with third-party manufacturers to manufacture, supply, store and distribute supplies of our product candidates for our clinical trials. We have no current plans to build internal manufacturing capacity for any product candidate, and we have no long-term supply arrangements.

Our reliance on third-party manufacturers exposes us to potential risks, such as the following:

•we may be unable to contract with third-party manufacturers on acceptable terms, or at all, because the number of potential manufacturers is limited. Potential manufacturers of any product candidate that is approved will be subject to regulatory compliance inspections and any new manufacturer would have to be qualified to produce our products;

•our third-party manufacturers might be unable to formulate and manufacture our product candidates and products in the volume and of the quality required to meet our clinical and commercial needs, if any;

•our third-party manufacturers may not perform as agreed or may not remain in the contract manufacturing business for the time required to supply our clinical trials through completion or to successfully produce, store and distribute our commercial products, if approved;

•drug manufacturers are subject to ongoing periodic unannounced inspection by the FDA and other government agencies to ensure compliance with cGMP and other government regulations and corresponding foreign standards. We do not have control over third-party manufacturers’ compliance with these regulations and standards, but we may ultimately be responsible for any of their failures;

•if any third-party manufacturer makes improvements in the manufacturing process for our product candidates, we may not own, or may have to share, the intellectual property rights to such improvements; and

•a third-party manufacturer may gain knowledge from working with us that could be used to supply one of our competitors with a product that competes with ours.

Each of these risks could delay or have other adverse impacts on our clinical trials and the approval and commercialization of our product candidates, potentially resulting in higher costs, reduced revenues or both.

Risks Related to Our Intellectual Property

Other companies or organizations may assert patent rights that prevent us from developing or commercializing our products.

RNAi and PD-L1 inhibitors have generated many different patent applications from organizations and individuals seeking to obtain patents in the field. These applications claim many different methods, compositions and processes relating to the discovery, development and commercialization of these therapeutic products. We are aware of patents and patent applications owned by third parties that may in the future be alleged by such third parties to cover the use of one or more of our products. We may need to acquire or obtain a license from such third parties to any such issued patents to market or sell any such products, which may not be available on commercially acceptable terms or at all.

Certain of our patents and patent applications have been challenged and found to be invalid, and additional challenges may occur in the future, which could adversely affect our business.

Certain United States, Canadian and international patents and patent applications we own involve complex legal and factual questions for which important legal principles are largely unresolved. For example, no consistent policy has emerged for the breadth of biotechnology patent claims that are granted by the USPTO or enforced by the United States federal courts. In addition, the coverage claimed in a patent application can be significantly reduced before a patent is issued. Also, we face at least the following intellectual property risks:

•some or all patent applications may not result in the issuance of a patent;

•patents issued to us may not provide us with any competitive advantages;

•patents could be challenged by third parties;

•competitors may find ways to design around our patents; and

•competitors could independently develop products which duplicate our products.

A number of industry competitors and institutions have developed technologies, filed patent applications or received patents on various technologies that may be related to or affect our business. Some of these technologies, applications or patents may conflict with our technologies or patent applications. Such conflict could limit the scope of the patents, if any, that we may be able to obtain or result in the denial of our patent applications. In addition, we could incur substantial costs in filing suits against others to have such patents declared invalid. Any future proceedings could result in substantial costs, even if the eventual outcomes are favorable. There can be no assurance that our patents, if issued, will be held valid or enforceable by a court or that a competitor’s technology or product would be found to infringe such patents.

For example, in April 2023, following the institution of inter partes review of a patent in our LNP patent portfolio, such patent was found to be invalid, and in January 2026, the EPO revoked our ’254 Patent. For more information on past and ongoing intellectual property challenges and litigation, see “Item 3—Legal Proceedings.”

We have incurred, and may in the future continue to incur, substantial costs as a result of litigation or other proceedings relating to patent and other intellectual property rights, and we may not be successful in one or more of these lawsuits or

proceedings, any of which could have a material adverse effect on our business, financial condition and results of operations and could cause the market value of our common shares to decline.

There has been significant litigation in the biotechnology industry over contractual obligations, patents and other proprietary rights, and we may become involved in various types of litigation that arise from time to time. Involvement in litigation could consume a substantial portion of our resources, regardless of the outcome of the litigation. Counterparties in litigation may be better able to sustain the costs of litigation because they have substantially greater resources. If claims against us are successful, in addition to any potential liability for damages, we could be required to obtain a license, grant cross-licenses, and pay substantial milestones or royalties in order to continue to develop, manufacture or market the affected products. Involvement and continuation of involvement in litigation may result in significant and unsustainable expense, and divert management’s attention from ongoing business concerns and interfere with our normal operations. Litigation is also inherently uncertain with respect to the time and expenses associated therewith, and involves risks and uncertainties in the litigation process itself, such as discovery of new evidence or acceptance of unanticipated or novel legal theories, changes in interpretation of the law due to decisions in other cases, the inherent difficulty in predicting the decisions of judges and juries and the possibility of appeals. Ultimately, we could be prevented from commercializing a product or be forced to cease some aspect of our business operations as a result of claims of patent infringement or violation of other intellectual property rights and the costs associated with litigation, which could have a material adverse effect on our business, financial condition, and operating results and could cause the market value of our common shares to decline.

Additionally, we continue to protect and defend our intellectual property rights, certain of which are the subject of an ongoing lawsuit against Pfizer/BioNTech, and if filed by Moderna, the Moderna §1498 Appeal, for their use of our patented LNP technology in their COVID-19 mRNA-LNP vaccines. We are also involved in a lawsuit 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. These lawsuits consume significant resources. Should we not be successful in one or more of these lawsuits, it could have a material adverse effect on our business, financial condition, and operating results and could cause the market value of our common shares to decline. For more information on past and ongoing intellectual property challenges and litigation, see “Item 3—Legal Proceedings.”

Confidentiality agreements with employees and others, including collaborators, may not adequately prevent disclosure of trade secrets and other proprietary information.

Much of our know-how and technology may constitute trade secrets. There can be no assurance, however, that we will be able to meaningfully protect our trade secrets. In order to protect our proprietary technology and processes, we rely in part on confidentiality agreements with our collaborators, employees, vendors, consultants, outside scientific collaborators and sponsored researchers, and other advisors. These agreements offer only limited protection, and as such may not effectively prevent disclosure of confidential information and also may not provide an adequate remedy in the event of unauthorized disclosure of confidential information. In addition, others may independently discover trade secrets and proprietary information, and in such cases, we could not assert any trade secret rights against such party. Costly and time consuming litigation could continue to be necessary to enforce and determine the scope of our proprietary rights, and failure to obtain or maintain trade secret protection could adversely affect our competitive business position.

Risks Related to the Ownership of our Common Shares

The concentration of common share ownership will likely limit the ability of the other shareholders to influence corporate matters.

As of March 18, 2026, executive officers, directors, five percent or greater shareholders, and their respective affiliated entities beneficially owned, in the aggregate, approximately 38% of our outstanding common shares.

Entities associated with Roivant Sciences Ltd. (Roivant) collectively held as a group approximately 20% of our outstanding common shares as of March 18, 2026.

As a result, Roivant can significantly influence the outcome of matters requiring shareholder approval, including the election of directors, amendments of our organizational documents, or approval of any merger, sale of assets or other major corporate transaction. This may prevent or discourage unsolicited acquisition proposals or offers for our common shares that you may feel are in your best interest. These actions might affect the prevailing market price for our common shares. In addition, Roivant and certain of our other principal shareholders that have held their shares for several years may be more interested in selling our company to an acquirer than other investors, or they may want us to pursue strategies that deviate from the interests of other shareholders. Such concentration of ownership control may also:

•delay, defer or prevent a change in control;

•entrench our management and/or our Board; or

•impede a merger, consolidation, takeover or other business combination involving us that other shareholders may desire.

We are incorporated in Canada, with our assets located both in Canada and the United States, with the result that it may be difficult for investors to enforce judgments obtained against us or some of our officers.

We are incorporated under the laws of the Province of British Columbia and some of our assets are located outside the United States. While we have appointed National Registered Agents, Inc. as our agent for service of process to effect service of process within the United States upon us, it may not be possible for you to enforce against us or our insiders in the United States, judgments obtained in United States courts based upon the civil liability provisions of the United States federal securities laws or other laws of the United States. In addition, there is doubt as to whether original action could be brought in Canada against us or our directors or officers based solely upon United States federal or state securities laws and as to the enforceability in Canadian courts of judgments of United States courts obtained in actions based upon the civil liability provisions of United States federal or state securities laws.

Conversely, all of our directors and officers reside outside Canada, and the majority of our physical assets are also located outside Canada. While we have appointed Farris LLP as our agent for service of process in Canada, it may not be possible for you to enforce in Canada against our assets or those directors and officers residing outside Canada, judgments obtained in Canadian courts based upon the civil liability provisions of the Canadian securities laws or other laws of Canada.

If we are deemed to be a “passive foreign investment company” for the current or any future taxable year, investors who are subject to United States federal taxation would likely suffer materially adverse United States federal income tax consequences.

We generally will be a “passive foreign investment company” under the meaning of Section 1297 of the Code (a PFIC) if (a) 75% or more of our gross income is “passive income” (generally, dividends, interest, rents, royalties, and gains from the disposition of assets producing passive income) in any taxable year, or (b) if at least 50% or more of the quarterly average value of our assets produce, or are held for the production of, passive income in any taxable year. We have determined that we have not been a PFIC for the three taxable years ended December 31, 2025, however recent changes to Treasury regulations under the Code have made this determination more challenging for us, and we cannot provide any assurances that we will not become a PFIC in the future. If we are a PFIC for any taxable year during which a United States person holds our common shares, it would likely result in materially adverse United States federal income tax consequences for such United States person, including, but not limited to, any gain from the sale of our common shares would be taxed as ordinary income, as opposed to capital gain, and such gain and certain distributions on our common shares would be subject to an interest charge, except in certain circumstances. It may be possible for United States persons to fully or partially mitigate such tax consequences by making a “qualifying electing fund election,” as defined in the Code (a QEF Election), but although we have provided this information in the past, there is no requirement that we do so.

Our preferred shares are available for issuance from time to time at the discretion of our Board, without shareholder approval.

In addition, limitations on the ability to acquire and hold our common shares may be imposed by the Competition Act in Canada. This legislation permits the Commissioner of Competition of Canada to review any acquisition of a significant interest in us. The Investment Canada Act subjects an acquisition of control of a Canadian-company by a non-Canadian to government review if the value of our assets, as calculated pursuant to the legislation, exceeds a threshold amount. A reviewable acquisition may not proceed unless the relevant minister is satisfied that the investment is likely to result in a net benefit to Canada. Any of the foregoing could prevent or delay a change of control and may deprive or limit strategic opportunities for our shareholders to sell their shares.

General Risk Factors

We could face liability from our controlled use of hazardous and radioactive materials in our development processes.

We use certain radioactive materials, biological materials and chemicals, including organic solvents, acids and gases stored under pressure, in our development activities. Our use of biological materials and chemicals, including the use, manufacture, storage, handling and disposal of such materials and certain waste products is regulated by a number of federal, state and local laws and regulations. Although we believe that our safety procedures for handling such materials comply with the standards prescribed by such laws and regulations, the risk of accidental contamination or injury from these materials cannot be completely eliminated. In the event of such an accident, we could be held liable for any damages that result or penalized with fines, and any such liability could exceed our resources. We are not specifically insured with respect to this liability.

Our business, reputation, and operations could suffer in the event of information technology system failures, such as a cybersecurity incident.

We are increasingly dependent on sophisticated software applications and computing infrastructure to conduct critical operations. We depend on both our own systems, networks, and technology as well as the systems, networks and technology of our contractors, consultants, vendors and other business partners. Disruption, degradation, or manipulation of systems, networks or technology through intentional or accidental means could materially adversely impact key business processes. These threats may arise from persons inside our organization, authorized persons with access to systems inside our organization or those with whom we do business, or unauthorized individuals. For example, the loss of preclinical trial data or data from completed or ongoing clinical trials for our product candidates could result in delays in our regulatory filings and development efforts and significantly increase our costs. There can be no assurance that our efforts to protect data and systems will prevent service interruption or the loss of critical or sensitive information from our or third-party providers’ systems, networks and technologies. The cost and operational consequences of responding to cybersecurity incidents, including disruption, degradation, or manipulation of systems, networks or technology, or implementing remediation measures could be significant. Threat actors may use AI tools to automate and enhance cybersecurity attacks against us. We use software and platforms designed to detect such cybersecurity threats, including AI-based tools, but these threats could become more sophisticated and harder to detect and counteract, which may pose significant risks to our data security and systems. Additionally, while we have implemented security measures that we believe are appropriate and continue to enhance cybersecurity protections, a regulator could deem our security measures not to be appropriate given the lack of prescriptive measures in certain data protection laws. Increased regulation of data collection, use and retention practices, including self-regulation and industry standards, changes in existing laws and regulations, enactment of new laws and regulations, increased enforcement activity, and changes in interpretation of laws, could increase our cost of compliance and operation, limit our ability to grow our business or otherwise harm our business. We rely on third party vendors and service providers to support various aspects of our business process. However, these third parties may pose risks related to data security, compliance, and contractual obligations. A breach or failure by a third party to adequately protect our data could have adverse consequences for our business and reputation.

To the extent that any disruption or cybersecurity incident results or appears to result in such interruption or loss, we could incur material financial, legal, business or reputational harm, including regulatory fines, penalties, scrutiny, or intervention, or

claims by third parties, including that we have breached privacy- or confidentiality-related obligations. A significant cybersecurity incident may also deter new clinical trial participants from participating in our trials. Furthermore, if our systems, networks, and technology, or those of third parties on which we rely, suffer severe damage, disruption or shutdown and our business continuity plans do not effectively resolve the issues in a timely manner, we could experience delays in reporting our financial results and the development of our product candidates could be delayed. Moreover, our insurance may not provide any or adequate coverage of any such losses. And, as cyberattacks increase in frequency and magnitude, we may be unable to obtain insurance in amounts and on terms we view as adequate for our operations.

We may form strategic alliances or collaborations that could harm our financial condition, results of operations or cash flows, dilute our shareholders’ ownership, incur debt or cause us to incur significant expense.

As part of our business strategy, we may pursue strategic alliances or collaborations. We may not identify or complete these transactions in a timely manner, on a cost-effective basis, or at all, and we may not realize the anticipated benefits of any such transaction, any of which could have a detrimental effect on our financial condition, results of operations or cash flows. We may not be able to find suitable collaboration partners.

Any such issuance of shares would dilute the ownership of our shareholders. Additional capital may not be available on terms that are favorable to us, or at all.

Item 1B. Unresolved Staff Comments

There are currently no unresolved staff comments.

Cybersecurity

We are increasingly dependent on sophisticated software applications and computing infrastructure to conduct key operations. We depend on both our own systems, networks, and technology as well as the systems, networks and technology of our contractors, consultants, vendors and other business partners.

Cybersecurity Program

Given the importance of cybersecurity to our business, we maintain a robust and comprehensive cybersecurity program to support both the effectiveness of our systems and our preparedness for information security risks. This program includes a number of administrative, physical and technical safeguards, with regular evaluations of our cybersecurity posture, including internal and external audits, as well as annual penetration tests. We also require cybersecurity training when onboarding new employees and contractors and on an annual basis thereafter. Our cybersecurity program leverages industry frameworks, including the National Institute of Standards and Technology (NIST) Cybersecurity Framework to strengthen our program effectiveness and reduce cybersecurity risks.

We use a risk-based approach with respect to our oversight of third-party service providers. As part of our process for onboarding new vendors, we assess new third-party service providers for technical capabilities, reputation, financial stability, pricing, and other criteria and such third-party service providers are reviewed and approved by our Finance and Legal departments. We have implemented processes to confirm that agreements with third-parties contain data security and privacy terms as appropriate. For certain key third-party service providers, we obtain a SOC type 2 audit report from the vendor’s audit firm which provides detailed information and assurance about a service organization’s security, availability, processing integrity, confidentiality and privacy controls.

Process for Assessing, Identifying and Managing Material Risks from Cybersecurity Threats

In the event of a cybersecurity incident, we maintain a regularly tested Incident Management and Response program as well as business continuity and disaster recovery plans. Pursuant to the program and its escalation protocols, designated personnel are responsible for assessing the severity of an incident and associated threat and handling it in accordance with that severity level.

We have relationships with a number of third-party service providers to assist with cybersecurity evaluation, containment and remediation efforts.

Governance

Management Oversight

The controls and processes employed to assess, identify and manage material risks from cybersecurity threats are implemented and overseen by our Executive Director of IT and Information Security (ED, IT & IS), who reports to our Chief Financial Officer. Our ED, IT & IS has over 30 years of IT experience and an Advanced Graduate Certification in Cybersecurity. He is responsible for the day-to-day management of the cybersecurity program, including the prevention, detection, investigation, response to, and recovery from cybersecurity threats and incidents, and is regularly engaged to help ensure the cybersecurity program functions effectively in the face of evolving cybersecurity threats. He provides regular briefings (quarterly at a minimum) to our Computer Security Incident Response Team consisting of the Chief Financial Officer and General Counsel/Chief Compliance Officer on cybersecurity matters, including threats, events, and program enhancements.

Board Oversight

While our Board of Directors has overall responsibility for risk oversight, our Audit Committee oversees cybersecurity risk matters. The Audit Committee is responsible for reviewing, discussing with management, and overseeing our data privacy, information technology and security and cybersecurity risk exposures. On at least an annual basis, the ED, IT & IS reports to the Audit Committee on information security and cybersecurity matters, including significant information technology risks, significant threats (and the potential impact of those exposures on our business, financial results, operations and reputation) and the steps implemented by management to monitor and mitigate exposures. He also apprises the Audit Committee promptly of high priority cybersecurity incidents, consistent with our Incident Management and Response Policy, and provides updates to the full Board as needed.

Cybersecurity Risks

Management assesses the top organizational risks for the Company on an annual basis. Our cybersecurity risk is a component of our overall organizational risk assessment. Management also performs a specific cybersecurity risk assessment based on the NIST cybersecurity risk framework. As part of our cybersecurity risk assessment, department leaders identify, assess and evaluate risks impacting our operations across the Company, including those risks related to cybersecurity. Department leaders are asked to consider the severity and likelihood of certain risk factors, drawing upon their company knowledge and past business experience. Our cybersecurity risk assessment helps to inform our risk mitigation strategies. While we maintain a robust cybersecurity program, the techniques used to infiltrate information technology systems continue to evolve. Accordingly, we may not be able to timely detect threats or anticipate and implement adequate security measures. For additional information, see “Item 1A—Risk Factors.”

We also maintain cybersecurity insurance providing coverage for certain costs related to cybersecurity-related incidents that impact our own systems, networks, and technology or the systems, networks and technology of our contractors, consultants, vendors and other business partners.

As of December 31, 2025, we have not experienced any material risks from cybersecurity threats, including as a result of any previous cybersecurity incidents or threats, that have materially affected our business strategy, results of operations or financial condition or are reasonably likely to have such a material effect.

Recently Filed

Click on a ticker to see risk factors

Ticker *	File Date
AMBA	57 minutes ago
PRXK	an hour ago
TCRG	an hour ago
RMBI	2 hours ago
MOJO	3 hours ago
COCH	5 hours ago
MAIA	6 hours ago
BALY	6 hours ago
TBPH	6 hours ago
AGIG	6 hours ago
NBRG	7 hours ago
SBDS	7 hours ago
XLO	7 hours ago
CABA	7 hours ago
ABUS	7 hours ago
PYXS	7 hours ago
AVTX	8 hours ago
IDR	8 hours ago
CLB	2 days, 17 hours ago
ATER	2 days, 17 hours ago
CGCT	2 days, 18 hours ago
FINW	2 days, 19 hours ago
SUNE	2 days, 21 hours ago
AHT	2 days, 21 hours ago
WGRX	2 days, 21 hours ago
EGHA	2 days, 21 hours ago
AIIA	2 days, 21 hours ago
VNME	2 days, 21 hours ago
SINT	2 days, 22 hours ago
NMP	2 days, 22 hours ago
ASTI	2 days, 22 hours ago
CELZ	2 days, 22 hours ago
USGO	2 days, 22 hours ago
FIEE	2 days, 22 hours ago
DNMX	2 days, 22 hours ago
SPFX	2 days, 22 hours ago
STRR	2 days, 22 hours ago
LWLG	2 days, 22 hours ago
UONE	2 days, 22 hours ago
GRWG	2 days, 22 hours ago
AFBI	2 days, 22 hours ago
SWKH	2 days, 22 hours ago
AACI	2 days, 22 hours ago
PALI	2 days, 22 hours ago
CBNA	2 days, 22 hours ago
TWAV	2 days, 22 hours ago
BLRK	2 days, 22 hours ago
JACS	2 days, 22 hours ago
SNOW	2 days, 22 hours ago
MLAA	2 days, 23 hours ago

OTHER DATASETS

House Trading

Dashboard

Corporate Flights

Dashboard

App Ratings

Dashboard

Strategies

Alerts

Browse Data

Risk Factors Dashboard

View risk factors by ticker

Search filings by term

Risk Factors - ABUS

-New additions in green
-Changes in blue
-Hover to see similar sentence in last filing

Recently Filed

OTHER DATASETS

House Trading

Corporate Flights

App Ratings

TRADE SMARTER

TRADE SMARTER

Strategies

Alerts

Browse Data

Risk Factors Dashboard

View risk factors by ticker

Search filings by term

Risk Factors - ABUS

-New additions in green-Changes in blue-Hover to see similar sentence in last filing

Recently Filed

OTHER DATASETS

House Trading

Corporate Flights

App Ratings

TRADE SMARTER

TRADE SMARTER

-New additions in green
-Changes in blue
-Hover to see similar sentence in last filing