Company: ABUS
Filing Date: 2025-08-06
Form Type: 10-Q
Source: 0001447028-25-000115
Chunk: 50

Company: Arbutus Biopharma Corp
Filing Date: 2025-08-06
Form: 10-Q
Item: Part I, Item 1
Chunk 50
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 week 48, all patients were evaluated for eligibility to discontinue NA therapy and are being 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 

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while remaining on NA therapy. At week 48, all patients were evaluated for eligibility to discontinue NA therapy, and are being followed for an additional 24 to 48 weeks. 

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 loss in cHBV patients and that 23% (3/13) of patients who received the treatment regimen with low dose nivolumab achieved HBsAg loss 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. 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, Grade 3 or 4 adverse events, immune-related adverse events, or discontinuations due to adverse events.

The IM-PROVE II clinical trial is being managed by us, subject to oversight by a joint development committee comprised of representatives from both companies. We and Barinthus retain full rights to our respective product candidates and are splitting all costs associated with the clinical trial. Pursuant to the agreement, the parties could have undertaken a larger Phase 2b clinical trial depending on the results of the initial Phase 2a clinical trial. However, in January 2025, Barinthus announced a shift in its strategic business focus that included postponing further development of VTP-300 after its ongoing VTP