Company: ABUS
Filing Date: 2025-08-06
Form Type: 10-Q
Source: 0001447028-25-000115
Chunk: 49

Company: Arbutus Biopharma Corp
Filing Date: 2025-08-06
Form: 10-Q
Item: Part I, Item 1
Chunk 49
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 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 loss that was associated with transient HBV RNA elevations that were preceded by or coincided with increases in immunological markers. 

These data from the IM-PROVE I trial suggest that the combination of imdusiran and 24 weeks of 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 transient alanine aminotransferase elevations and injection site bruising. 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 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