Vir Biotechnology will present pivotal 48-week results from its Phase 2 SOLSTICE clinical trial evaluating combination therapy for chronic hepatitis delta at the American Association for the Study of Liver Diseases (AASLD) The Liver Meeting 2025 in Washington, D.C., November 7-11. The presentation will showcase data on tobevibart alone or in combination with elebsiran, building on previously reported positive outcomes.
SOLSTICE Trial Results Build on Earlier Success
The Week 48 endpoint results follow positive data presented at AASLD The Liver Meeting 2024, which demonstrated rapid and sustained rates of virologic suppression at Week 24 and beyond. Dr. Tarik Asselah, Professor of Hepatology at the Hôpital Beaujon, APHP, Clichy, France, and at the University of Paris, and Head of Viral Hepatitis at INSERM UMR1149, France, will present the efficacy and safety findings on Sunday, November 9, from 6:00 pm to 6:15 pm ET during the "Next-generation HBV Therapeutics: Emerging Therapies and Search for Functional Cure" session.
ECLIPSE Registrational Program Advances
Vir Biotechnology will also present a poster detailing ECLIPSE, the company's registrational program currently enrolling patients. The program evaluates the safety and efficacy of the combination of tobevibart and elebsiran in patients with chronic hepatitis delta. Dr. Nancy Reau, Section Chief of Hepatology at Rush University Medical Center, Chicago, will present the rationale, study design, and objectives on Saturday, November 8, from 8:00 am to 5:00 pm ET during the "Hepatitis - Other Infections" session.
Dual-Mechanism Therapeutic Approach
Tobevibart Mechanism of Action
Tobevibart is an investigational broadly neutralizing monoclonal antibody targeting the hepatitis B surface antigen (HBsAg). The therapeutic is designed to inhibit the entry of hepatitis B and hepatitis delta viruses into hepatocytes and to reduce the level of circulating viral and subviral particles in the blood. Tobevibart was identified using Vir Biotechnology's proprietary monoclonal antibody discovery platform.
The antibody features an engineered Fc domain to increase immune engagement and clearance of HBsAg immune complexes and incorporates Xencor's Xtend technology to extend half-life. Tobevibart is administered subcutaneously and is currently in clinical development for the treatment of patients with chronic hepatitis delta.
Elebsiran RNA Interference Strategy
Elebsiran is an investigational hepatitis B virus-targeting small interfering ribonucleic acid (siRNA) discovered by Alnylam Pharmaceuticals. It is designed to degrade hepatitis B virus RNA transcripts and limit the production of hepatitis B surface antigen. Current data indicate that it has the potential to have direct antiviral activity against hepatitis B virus and hepatitis delta virus. Elebsiran is administered subcutaneously and is currently in clinical development for the treatment of patients with chronic hepatitis delta.
The combination approach targets multiple pathways in the hepatitis delta virus lifecycle, potentially offering enhanced therapeutic efficacy compared to single-agent treatments. The ECLIPSE program represents a once-monthly combination therapy regimen, which could improve patient compliance and treatment outcomes in this challenging-to-treat patient population.
