Company: ABUS
Filing Date: 2025-05-14
Form Type: 10-Q
Source: 0001447028-25-000099
Chunk: 70

Company: Arbutus Biopharma Corp
Filing Date: 2025-05-14
Form: 10-Q
Item: Part I, Item 2
Chunk 70
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 in combination with Barinthus’ VTP-300

Through a clinical collaboration agreement with Barinthus that we entered into in July 2021, we have completed enrollment in 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 immunotherapy, administered after imdusiran in patients with cHBV infection. The initial trial design enrolled 40 NA-suppressed, HBeAg negative or positive, non-cirrhotic cHBV infected patients. The primary objective of this trial was to initially lower HBsAg levels with imdusiran and then administer VTP-300 as an immunomodulator to promote anti-HBV immune reawakening. 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 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 (Opdivo®), 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. 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