Company: ABUS
Filing Date: 2025-11-13
Form Type: 10-Q
Source: 0001447028-25-000126
Chunk: 49

Company: Arbutus Biopharma Corp
Filing Date: 2025-11-13
Form: 10-Q
Item: Part I, Item 1
Chunk 49
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 following treatment with imdusiran (46% (48/105) of all Phase 2a patients achieved functional cure or remained off NA therapy after discontinuing NA therapy following treatment with imdusiran). Of the 18 patients who consented to long-term follow-up, which includes all functionally cured patients and 10 patients who discontinued and remained off NA therapy for 48 weeks, 94% continue to remain off NA therapy for between 58 and 109 weeks. One functionally cured patient seroreverted but 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