Company: ABUS
Filing Date: 2025-08-06
Form Type: 10-Q
Source: 0001447028-25-000115
Chunk: 46

Company: Arbutus Biopharma Corp
Filing Date: 2025-08-06
Form: 10-Q
Item: Part I, Item 1
Chunk 46
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 The intent of these trials was to initially lower HBsAg levels with imdusiran and then administer a complementary agent, an immune modulator or a therapeutic vaccine, to further lower HBsAg levels and promote anti-HBV immunity. We believe that if we can lower HBsAg and promote immunity, we may achieve sustained HBsAg loss and HBV DNA <LLOQ, potentially leading to a functional cure in many patients with cHBV. 

To date, we have reported a total of eight patients with cHBV who have been functionally cured following treatment with imdusiran and ongoing nucleos(t)ide analogue (NA) therapy in combination with either IFN or with low dose nivolumab plus an immunotherapeutic. Two of the patients who achieved functional cure did not receive any IFN as part of the combination therapy. Seven of the eight patients who achieved functional cure had HBsAg less than 1000 IU/mL at baseline. According to the literature, patients with HBsAg levels <1000 IU/mL represent a significant portion of the cHBV population.

Our imdusiran development program includes the following two Phase 2a clinical trials:

•Imdusiran in combination with IFN, a standard-of-care immunomodulator, and ongoing standard-of-care NA therapy in patients with cHBV infection (IM-PROVE I). At the American Association for the Study of Liver Diseases (AASLD) – The Liver Meeting® in November 2024, we presented new data from our IM-PROVE I Phase 2a clinical trial showing that six doses of imdusiran and 24 weeks of IFN added to ongoing NA therapy led to a functional cure rate of 50% (3/6) in hepatitis B e antigen (HBeAg) negative patients with baseline HBsAg levels less than 1000 IU/

21

mL, and an overall functional cure rate of 25% (3/12). Additionally, three cHBV patients from other cohorts in the IM-PROVE I clinical trial achieved functional cure. Those patients who achieved a functional cure also seroconverted. These data from the IM-PROVE I trial suggest that the combination of imdusiran, 24 weeks of IFN and NA therapy was generally safe and well-tolerated.  

•Imdusiran in combination with VTP-300, Barinthus Biotherapeutics plc’s (Barinthus) HBV immunotherapy