8-K: Arbutus Biopharma Presents Promising Clinical Data on HBV Assets at EASL Congress 2025

Arbutus Biopharma announces the presentation of clinical trial data at the EASL Congress 2025, highlighting the potential of imdusiran and AB-101 in treating chronic hepatitis B.

Summary

• Arbutus Biopharma presented five posters at the European Association for the Study of the Liver (EASL) Congress 2025, featuring data on imdusiran and AB-101.
• A late-breaker poster presentation highlighted that imdusiran, combined with VTP-300 and low-dose nivolumab, achieved functional cure in some chronic hepatitis B (cHBV) patients.
• In a Phase 2a clinical trial (IM-PROVE II), three patients in Group C (with nivolumab) experienced HBsAg loss and seroconversion at week 48.
• All three patients who achieved HBsAg loss had baseline HBsAg levels below 1000 IU/mL.
• 25% (2/8) of Group C patients with baseline HBsAg <1000 IU/mL who received nivolumab reached functional cure with an overall functional cure rate in Group C of 15.3% (2/13).
• Most patients treated with imdusiran maintained lower HBsAg levels compared to pre-treatment levels during the post-treatment follow-up period.
• More patients treated with imdusiran and VTP-300 (Group A) were able to remain off NA therapy compared to placebo (Group B), even without achieving functional cure.
• The combination of imdusiran, VTP-300, and low-dose nivolumab was well-tolerated, with no serious adverse events, deaths, or early treatment discontinuations.
• A Phase 1a/1b clinical trial of AB-101, an oral PD-L1 inhibitor, showed it to be generally safe and well-tolerated with evidence of high receptor occupancy and no liver dysfunction in cHBV patients.
• 10mg of AB-101 for 28 days was well tolerated, with PD-L1 receptor occupancy similar to that observed in healthy volunteers who received multiple doses of AB-101 10mg once daily.

Sentiment

Score: 8

Explanation: The document presents positive clinical data, suggesting potential for Arbutus's HBV therapies. The achievement of functional cure in some patients and the favorable safety profile of AB-101 contribute to a positive outlook.

Positives

• Imdusiran shows promise in achieving functional cure for cHBV when combined with VTP-300 and low-dose nivolumab.
• AB-101 demonstrates a favorable safety profile and high receptor occupancy in early clinical trials.
• The combination of imdusiran, VTP-300, and low-dose nivolumab was well-tolerated, with no serious adverse events, deaths, or early treatment discontinuations.
• More patients treated with imdusiran and VTP-300 were able to remain off NA therapy compared to placebo, even without achieving functional cure.

Risks

• The forward-looking statements are subject to significant business, economic, competitive, market and social uncertainties and contingencies.
• Ongoing and anticipated clinical trials may be more costly or take longer to complete than anticipated, and may never be initiated or completed, or may not generate results that warrant future development of the tested product candidate.
• Arbutus may elect to change its strategy regarding its product candidates and clinical development activities.
• Arbutus may not receive the necessary regulatory approvals for the clinical development of Arbutus products.
• Economic and market conditions may worsen; and market shifts may require a change in strategic focus.

Future Outlook

The press release highlights the potential of imdusiran and AB-101 in treating chronic hepatitis B, suggesting continued development and clinical trials for these assets.

Management Comments

• Dr. Grace Lai-Hung Wong, Professor of The Chinese University of Hong Kong, commented that lowering HBsAg with imdusiran prior to adding additional therapies to promote HBV-specific immune reawakening is beneficial.
• Dr. Wong also stated that adding a low dose of nivolumab to the imdusiran and VTP-300 treatment regimen, with ongoing NA therapy in CHB patients, is well-tolerated and leads to more patients achieving HBsAg loss and reaching a functional cure.

Industry Context

The announcement positions Arbutus Biopharma as a key player in the development of novel therapies for chronic hepatitis B, a significant global health challenge. The focus on achieving functional cure through combination therapies aligns with current research trends in the HBV field.

Comparison to Industry Standards

• The functional cure rates achieved with imdusiran in combination with VTP-300 and low-dose nivolumab are promising compared to existing treatments for chronic hepatitis B, which primarily focus on viral suppression.
• Companies like Gilead Sciences and Vir Biotechnology are also developing novel HBV therapies, including RNAi therapeutics and immunomodulatory agents, making the competitive landscape intense.
• The safety profile of AB-101, an oral PD-L1 inhibitor, is notable, as systemic immune checkpoint inhibitors have been associated with significant adverse events.

Stakeholder Impact

• Positive results could lead to increased shareholder value.
• Successful development of new HBV therapies could improve the lives of millions of patients worldwide.
• Positive clinical data may attract potential partners or investors.

Next Steps

• Continued clinical development of imdusiran and AB-101.
• Further analysis of data from the IM-PROVE II trial.
• Potential initiation of further clinical trials to evaluate the combination of imdusiran, VTP-300, and low-dose nivolumab.
• Presentation of additional data at future scientific conferences.

Key Dates

Keywords

Imdusiran, AB-101, Hepatitis B, HBV, Functional Cure, EASL Congress, Clinical Trial, RNAi, PD-L1 Inhibitor, Arbutus Biopharma