10-Q: Arbutus Narrows Losses, Advances HBV Pipeline & LNP Litigation

Arbutus Biopharma reported significantly reduced net losses in Q3 2025, driven by cost-cutting and deferred revenue, while advancing its cHBV clinical programs and patent litigation.

Summary

• Net loss for the three months ended September 30, 2025, significantly decreased to $7.7 million from $19.7 million in the same period of 2024.
• Net loss for the nine months ended September 30, 2025, decreased to $29.7 million from $57.4 million in the same period of 2024.
• Total revenue for the three months ended September 30, 2025, decreased to $0.5 million from $1.3 million in the same period of 2024.
• Total revenue for the nine months ended September 30, 2025, increased to $13.0 million from $4.6 million in the same period of 2024, primarily due to the recognition of $9.6 million in deferred revenue from the terminated Qilu partnership.
• Research and development expenses decreased by $8.5 million for the three months and $25.0 million for the nine months ended September 30, 2025, compared to 2024, due to organizational streamlining and cessation of discovery efforts.
• General and administrative expenses decreased by $1.5 million for the three months and $5.2 million for the nine months ended September 30, 2025, compared to 2024, mainly due to reduced employee compensation and legal fees.
• Restructuring costs for the nine months ended September 30, 2025, were $12.6 million, significantly higher than $3.6 million in 2024, reflecting a 57% workforce reduction, exit from corporate headquarters, and discontinuation of in-house scientific research.
• Cash, cash equivalents, and investments in marketable securities totaled $93.7 million as of September 30, 2025.
• The company believes it has sufficient cash resources to fund its operations for at least the next 12 months.
• The US patent infringement lawsuit against Moderna is scheduled for a jury trial in March 2026.
• Five international lawsuits were filed against Moderna in March 2025 across 30 countries, with public oral hearings for Unified Patent Court cases scheduled for May 2026 and the Canadian trial for September 2027.
• The claim construction ruling in the Pfizer/BioNTech lawsuit in September 2025 was generally considered favorable.
• Clinical data from IM-PROVE I and IM-PROVE II trials for imdusiran showed functional cure rates and patients remaining off NA therapy, with beneficial outcomes across all evaluated HBV genotypes.
• AB-101 Phase 1a/1b clinical trial data showed the oral PD-L1 inhibitor was generally well-tolerated with high receptor occupancy.

Sentiment

Score: 7

Explanation: The sentiment is moderately positive. Significant reductions in net loss and operating expenses, coupled with favorable legal rulings and promising early clinical data for key pipeline assets, indicate positive operational and strategic execution. However, the company still faces substantial future funding needs, ongoing complex litigation, and a decrease in quarterly revenue, which temper the overall positive outlook.

Positives

• Net loss significantly decreased for both the three-month ($7.7M vs $19.7M) and nine-month ($29.7M vs $57.4M) periods ended September 30, 2025, compared to the prior year.
• Operating expenses, particularly R&D and G&A, saw substantial reductions due to strategic streamlining and cost management efforts.
• The US court issued a generally favorable claim construction ruling in the Pfizer/BioNTech patent infringement lawsuit in September 2025.
• Clinical data for imdusiran (AB-729) from IM-PROVE I and IM-PROVE II trials demonstrated functional cure rates (e.g., 50% in a specific IM-PROVE I cohort) and a significant number of patients (40 additional) remaining off NA therapy for at least 48 weeks.
• Imdusiran showed lasting durability, with 94% of 18 long-term follow-up patients remaining off NA therapy for 58 to 109 weeks.
• AB-101 Phase 1a/1b clinical trial showed the oral PD-L1 inhibitor was generally well-tolerated with evidence of high receptor occupancy.
• The company regained global rights for imdusiran following the mutual termination of the Qilu License Agreement in June 2025.
• The US Department of Justice filed a Statement of Interest in the Moderna lawsuit, and the court denied Moderna's motion to dismiss claims related to sales to the US Government.

Negatives

• Total revenue for the three months ended September 30, 2025, decreased to $0.5 million from $1.3 million in the prior year period, primarily due to lower ONPATTRO sales royalties.
• Cash, cash equivalents, and investments in marketable securities decreased to $93.7 million as of September 30, 2025, from $122.6 million at December 31, 2024.
• Significant restructuring costs of $12.6 million were incurred for the nine months ended September 30, 2025, due to workforce reductions and exiting corporate headquarters.
• Barinthus Biotherapeutics plc announced a shift in strategic business focus in January 2025, postponing further development of VTP-300, which was part of a combination treatment regimen with imdusiran in the IM-PROVE II trial, thus ending plans for a larger Phase 2b trial for that combination.

Risks

• Outcomes of ongoing patent infringement lawsuits against Moderna and Pfizer/BioNTech are inherently unpredictable and could materially affect financial condition.
• Substantial additional funds will be required to continue with the active development of pipeline products and technologies, and there is no assurance that funding will be available on acceptable terms.
• Delays in the development of product candidates due to preclinical and clinical findings could impact timelines and costs.
• The ability to obtain necessary regulatory approvals for product candidates is uncertain and critical for commercialization.
• Competition from other products, product candidates, and technological developments could impact market share and profitability.
• Manufacturing issues, such as batches failing to meet specifications, could lead to clinical trial delays and increased costs.
• The company may be required to relinquish rights to product candidates or technologies at an earlier stage or on less favorable terms if adequate funding is not secured.

Future Outlook

The company expects to significantly reduce its net cash burn in 2025 compared to 2024 due to organizational changes and ongoing cost management efforts. Substantial additional funds will be required to continue with the active development of pipeline products and technologies, which may be sought through various financing activities, monetization transactions, or collaborations. The company will continue to advance its cHBV development programs and defend its LNP technology intellectual property through ongoing litigation.

Management Comments

• We continue to protect and defend our intellectual property, which is the subject of our ongoing lawsuits against Moderna Therapeutics, Inc. and against Pfizer Inc. and BioNTech SE for their use of our patented lipid nanoparticle (LNP) technology.
• With these organizational changes and our ongoing cost management efforts, we expect to significantly reduce our net cash burn in 2025 when compared to 2024.
• 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.
• We remain committed to taking all legal actions necessary to defend and protect our intellectual property.
• Our HBV strategy has been to develop a functional cure for patients with cHBV infection with imdusiran as a potential cornerstone in a combination therapy.

Industry Context

Arbutus Biopharma operates in the highly competitive biopharmaceutical industry, focusing on infectious diseases, particularly chronic hepatitis B (cHBV). The development of a functional cure for cHBV remains a significant unmet medical need, with current treatments often requiring lifelong therapy or having poor tolerability. The company's LNP technology is central to its patent infringement lawsuits against major pharmaceutical players like Moderna and Pfizer/BioNTech, highlighting the critical role of drug delivery platforms in the mRNA vaccine and therapeutic space. The industry trend towards combination therapies and immune modulation for chronic viral infections is reflected in Arbutus's clinical programs for imdusiran and AB-101.

Management Changes

Corporate Governance

Legal Proceedings

• US Patent Infringement Lawsuit vs. Moderna: Filed February 28, 2022, seeking damages for infringement of six US patents related to LNP technology in Moderna's COVID-19 vaccine. Claim construction ruling in April 2024 was favorable. Jury trial scheduled for March 2026. Case reassigned to a different judge in July 2025.
• International Patent Infringement Lawsuits vs. Moderna: Five lawsuits filed March 3, 2025, across 30 countries, targeting Moderna's COVID-19 and RSV vaccines. Public oral hearings for Unified Patent Court cases in May 2026, Canadian trial in September 2027. Evidence submitted indicates LNP technology infringement.
• US Patent Infringement Lawsuit vs. Pfizer and BioNTech: Filed April 4, 2023, seeking damages for infringement of five US patents related to LNP technology in their COVID-19 mRNA-LNP vaccines. Claim construction ruling in September 2025 was generally favorable.
• Moderna and Merck European Oppositions (EP 2279254): Opposition filed April 5, 2018. EPO upheld an auxiliary request in October 2019. Appeals filed by Moderna and Merck. Oral proceedings held in June 2024, where the Opposition Division upheld the patent but declined broadening claims. Both parties appealed, with oral proceedings scheduled for January 2026.
• Moderna and Merck European Oppositions (EP 4241767): Moderna filed a revocation action on April 29, 2025. Merck, Arrowhouse GmbH, and Keltie LLP filed three additional revocation actions in July 2025. The company is preparing its response.

Related Party Transactions

• On August 5, 2025, the company entered into an agreement with Keith Manchester, M.D., a former Board member (until February 24, 2025), for consulting services regarding development strategy and hepatitis B programs. In connection with this, an option to purchase 400,000 common shares was granted to Dr. Manchester.

Stakeholder Impact

• Shareholders: Potential for significant returns from successful patent litigation or product commercialization, but also risk of dilution from future capital raises and uncertainty from clinical trial outcomes.
• Employees: Affected by significant workforce reductions (40% in 2024, additional 57% in March 2025) and changes in work environment (exit from corporate headquarters, discontinuation of in-house research).
• Customers (future cHBV patients): Potential for improved treatment options with imdusiran and AB-101 if clinical development is successful and leads to a functional cure.
• Creditors: No outstanding debt as of September 30, 2025, indicating a healthy balance sheet in this regard.

Next Steps

• Jury trial for the US patent infringement lawsuit against Moderna is scheduled for March 2026.
• Public oral hearings for the two Unified Patent Court cases against Moderna are scheduled for May 2026.
• The trial in the Canadian case against Moderna is set to begin in September 2027.
• Oral proceedings for the appeal of the EPO's decision on the 254 Patent are scheduled for January 2026.
• Preparing responses to the revocation actions filed against EPO patent EP 4 241 767 by Moderna, Merck, Arrowhouse GmbH, and Keltie LLP.

Key Dates

Recommendation

Arbutus Biopharma has shown significant progress in reducing its net loss and operating cash burn through aggressive restructuring and cost management. Positive clinical data for imdusiran and AB-101, coupled with favorable claim construction rulings in key patent litigations, provide a strong foundation. However, the company remains a clinical-stage entity with substantial future funding requirements for pipeline development and ongoing legal battles, which introduce considerable uncertainty. The termination of the Qilu partnership, while regaining global rights, also highlights the challenges in commercialization. Given the mix of promising clinical and legal developments against the backdrop of high R&D costs and future capital needs, a 'hold' recommendation is appropriate for investors monitoring long-term potential.

Keywords

Biopharma, Hepatitis B, HBV, RNAi therapeutic, imdusiran, AB-729, PD-L1 inhibitor, AB-101, LNP technology, patent litigation, Moderna, Pfizer, BioNTech, clinical trials, infectious disease, drug development, corporate restructuring