Company: ABUS
Filing Date: 2025-11-13
Form Type: 10-Q
Source: 0001447028-25-000126
Chunk: 81

Company: Arbutus Biopharma Corp
Filing Date: 2025-11-13
Form: 10-Q
Item: Part I, Item 2
Chunk 81
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 remains virally suppressed and off NA therapy. 

•AB-101 is our proprietary oral PD-L1 inhibitor that has the potential to reawaken patients’ HBV-specific immune response by inhibiting PD-L1. AB-101 is currently in a Phase 1a/1b clinical trial (AB-101-001) evaluating the safety, tolerability, pharmacokinetics (PK), and pharmacodynamics (PD) of single- and multiple-ascending oral doses in healthy subjects and patients with cHBV infection. The data from healthy subjects in Parts 1 and 2 and cHBV patients to date in Part 3 of this clinical trial have showed that AB-101 was generally well-tolerated with evidence of high receptor occupancy.   

To help position imdusiran as a potential cornerstone in a combination therapy, we fully enrolled two Phase 2a clinical trials that combined imdusiran with other agents. 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. Our belief in these trials was that if we can lower HBsAg and promote immunity, we may achieve sustained HBsAg seroclearance and HBV DNA <LLOQ, potentially leading to a functional cure in many patients with cHBV. Currently, patients with cHBV have limited treatment options - either NA therapy, which requires lifelong treatment, or a finite duration of IFN, which is poorly tolerated and has serious complications and side effects. We believe patients can see significant benefits even without functional cure if they are well enough to be able to discontinue NA therapy and maintain viral suppression.

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To date, a total of eight patients with cHBV achieved functional cure following treatment with imdusiran and NA therapy in combination with either IFN or with low dose nivolumab plus an immunotherapeutic, with seven of the eight patients continuing to sustain functional cure for periods ranging between 58 to 109 weeks. Seven of the eight total patients who achieved functional cure at the 60mg dose of imdusiran 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. In addition to the patients who achieved functional cure, 40 more patients were able to remain off NA therapy for