Moderna litigation U.S. trial scheduled for March 2026;
Favorable claim construction ruling in Pfizer-BioNTech litigation issued in September 2025
Additional analysis of imdusiran (AB-729) clinical data shows:
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46% of Phase 2a patients met criteria to discontinue all treatment
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94% of long-term follow-up patients remain off all treatment for up to 2+ years
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100% of HBV DNA positive patients in Phase 1b achieved HBV DNA levels belowquantification after only 18 weeks of imdusiran and nucleos(t)ide analogue therapy
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All HBV e-antigen positive patients demonstrated dose-dependent HBV e-antigen decreases
WARMINSTER, Pa., Nov. 13, 2025 (GLOBE NEWSWIRE) -- Arbutus Biopharma Corporation (NASDAQ:ABUS) ("Arbutus" or the "Company"), a clinical-stage biopharmaceutical company focused on infectious disease, today reported third quarter 2025 financial results and provided a corporate update.
"The strength of our third quarter performance reflects our disciplined focus on executing strategic priorities," said Lindsay Androski, President and CEO of Arbutus. "We are also excited to share additional analysis of imdusiran clinical data being conducted as part of our ongoing strategic review. Notably, in addition to the eight patients who initially achieved functional cure with imdusiran at 60mg in our Phase 2a trials, forty more patients across all cohorts discontinued nucleos(t)ide analogue therapy after meeting study-defined criteria. In total, a combined 46% of all Phase 2a patients were able to discontinue all treatment. All but one patient who achieved functional cure or who we are following after discontinuing nucleos(t)ide analogue therapy remain off all treatment long-term, now exceeding two years for some patients. Across our Phase 1b and Phase 2a trials, imdusiran has demonstrated sustained benefits in chronic hepatitis B patients, regardless of baseline hepatitis B surface antigen levels, hepatitis B virus DNA presence or absence, and hepatitis B e-antigen positivity or negativity. We remain dedicated to accelerating the development and potential approval of imdusiran."
LNP Litigation
Arbutus continues to consult closely with and support its exclusive licensee, Genevant Sciences, to protect and defend Arbutus's intellectual property, which is the subject of on-going lawsuits against Moderna and Pfizer/BioNTech. The Company, together with Genevant, is seeking fair compensation for Moderna's and Pfizer/BioNTech's use of Arbutus's patented LNP technology that was developed with great effort and at a great expense, and without which Moderna's and Pfizer/BioNTech's COVID-19 vaccines would not have been successful.
In the Moderna U.S. litigation, fact discovery, expert discovery and summary judgment briefing have been completed. A jury trial is scheduled for March 2026. In March 2025, the Company, alongside Genevant Sciences, filed five international lawsuits against Moderna and its affiliates seeking to enforce patents protecting the Company's patented LNP technology across 30 countries. Public oral hearings for two of the five cases which are before the Unified Patent Court are scheduled for May 2026, and a trial in the Canadian case is set to begin in September 2027.
The claim construction hearing for the lawsuit against Pfizer/BioNTech occurred in December 2024, and the court issued a claim construction ruling in September 2025, which construed the disputed claim terms in a manner the Company generally considers to be favorable.
Corporate Updates
The Company showcased four poster presentations featuring data from its hepatitis B virus (HBV) programs at AASLD 2025. One poster presented new analysis from the Company's IM-PROVE I Phase 2a clinical trial showing beneficial clinical outcomes were observed across all evaluated HBV genotypes (A to E). The Company also had a Poster of Distinction highlighting AB-101's maximal PD-L1 receptor occupancy between 68-100% at a 30mg daily dose.
Today, the Company published an updated Corporate Presentation on its website, which includes the results of its recently completed analysis of imdusiran clinical data.
In addition to the eight functional cures, an additional 40 patients across all cohorts in its Phase 2a trials met study-defined criteria for nucleos(t)ide analogue (NA) therapy discontinuation.
In total, 46% (48/105) of all Phase 2a patients either achieved functional cure or remained off NA therapy for at least 48 weeks after discontinuing NA therapy following treatment with imdusiran.
Eighteen patients consented to long-term follow-up, including all functionally cured patients and 10 patients who discontinued NA therapy. To date, 94% of those follow-up patients have remained off all treatment for between 58 to 109 weeks. One functionally cured patient seroreverted but remains virally suppressed and off all treatment.
Additionally, 56% (5/9) of Phase 1b patients (only received imdusiran and NA therapy) who elected to discontinue NA therapy, remained off all treatment for at least 3 years.
Imdusiran has also demonstrated steep and durable declines in HBV DNA, and, with NA therapy, achieved full HBV DNA suppression significantly faster than NA therapy alone. By week 18 of treatment with imdusiran and NA therapy, 100% of Phase 1b HBV DNA positive patients achieved HBV DNA levels below the level of quantification, The eight Phase 2a patients who achieved functional cure continue to have HBV DNA levels below the level of quantification.
In 30 hepatitis B e-antigen (HBeAg) positive patients in our Phase 1 and 2a trials, HBeAg decreased in all patients in a dose-dependent manner.
Financial Results
Cash, Cash Equivalents and Investments
As of September 30, 2025, the Company had cash, cash equivalents and investments in marketable securities of $93.7 million compared to $122.6 million as of December 31, 2024. During the nine months ended September 30, 2025, the Company used $35.0 million in operating activities, which included one-time payments related to its restructuring efforts. This was partially offset by $3.9 million of proceeds from the exercise of stock options.
Revenue
Total revenue was $0.5 million for the quarter ended September 30, 2025, compared to $1.3 million for the same period in 2024. The decrease of $0.8 million was due to a decrease in license royalty revenues, primarily due to a decline in Alnylam's sales of ONPATTRO.
Operating Expenses
Research and development expenses were $5.8 million for the quarter ended September 30, 2025, compared to $14.3 million for the same period in 2024. The decrease of $8.5 million was due primarily to cost savings from the Company's decisions to streamline the organization to focus its efforts on advancing the clinical development of imdusiran and AB-101, which included ceasing all discovery efforts, discontinuing its IM-PROVE III clinical trial, and reducing the Company's workforce.
General and administrative expenses were $3.0 million for the quarter ended September 30, 2025, compared to $4.5 million for the same period in 2024. This decrease was due primarily to cost-cutting efforts by the Company, which drove reductions in employee compensation-related expenses and legal fees.
Restructuring costs in the quarter ended September 30, 2025 were $0.1 million, and all remaining restructuring-related payments are expected to be made by the first quarter of 2026.
Net Loss
For the quarter ended September 30, 2025, the Company's net loss was $7.7 million, or a loss of $0.04 per basic and diluted common share, as compared to a net loss of $19.7 million, or a loss of $0.10 per basic and diluted common share, for the quarter ended September 30, 2024.
Outstanding Shares
As of September 30, 2025, the Company had 192.0 million common shares issued and outstanding, as well as 14.9 million stock options and unvested restricted stock units outstanding.
UNAUDITED CONDENSED CONSOLIDATED STATEMENTS OF INCOME AND LOSS(in thousands, except share and per share data)
Three Months Ended September 30,
Nine Months Ended September 30,
2025
2024
2025
2024
Revenue
Collaborations and licenses
$
280
$
767
$
11,809
$
2,861
Non-cash royalty revenue
249
572
1,223
1,736
Total Revenue
529
1,339
13,032
4,597
Operating expenses
Research and development
5,778
14,273
20,235
45,227
General and administrative
3,044
4,537
12,204
17,396
Change in fair value of contingent consideration
268
344
827
735
