Vir Biotechnology Announces AASLD The Liver Meeting Presentation & New England Journal of Medicine Publication of Phase 2 Data Demonstrating Tobevibart & Elebsiran Combination Deliver High Rates of Undetectable HDV RNA with Favorable Safety Profile

Vir Biotechnology, Inc. (Nasdaq: VIR) today announced that Week 48 endpoint analysis from the Company’s Phase 2 SOLSTICE trial for chronic hepatitis delta (CHD) demonstrated that participants receiving a monthly dose of the combination of tobevibart and elebsiran achieved robust and sustained rates of hepatitis delta virus (HDV) RNA target not detected (TND), including those participants with cirrhosis and high baseline HDV RNA. The combination also showed alanine aminotransferase (ALT) reductions over time and a favorable safety profile. These data were presented in an oral session at the American Association for the Study of Liver Diseases (AASLD) The Liver Meeting , in Washington, D.C., and simultaneously published in the New England Journal of Medicine.

“Achieving undetectable HDV RNA is a key endpoint in clinical trials, and HDV RNA undetectability is associated with better outcomes for people living with chronic hepatitis delta,” said Tarik Asselah, M.D., Ph.D., Professor of Hepatology at the Hôpital Beaujon, APHP, Clichy, France, and at the University of Paris-Cité, and Head of the unit Viral Hepatitis UMR1149 at INSERM, France. “The combination of tobevibart and elebsiran has consistently demonstrated impressive hepatitis delta virologic suppression in the SOLSTICE Phase 2 trial, and these 48-week data are encouraging as they continue to support its potential to deliver meaningful patient benefit.”

Data demonstrate that 66% (21/32) of participants with CHD receiving a monthly dose of the combination of tobevibart and elebsiran achieved and sustained HDV RNA TND at 48 weeks. Additionally, approximately 90% of participants achieved reduction in hepatitis B surface antigen (HBsAg) to values <10 IU/mL by Week 48. HBsAg reduction indicates suppression of the fundamental biologic mechanisms that HDV requires for viral replication. ALT was normalized in 56% (18/32) of participants by Week 48. The combination was well-tolerated, with no grade 3 or higher treatment-related adverse events and no treatment-related discontinuations. Most treatment-related adverse events were generally mild to moderate and transient.

The combination of tobevibart and elebsiran is currently being evaluated in Vir Biotechnology’s ECLIPSE registrational program for the treatment of CHD, which includes three randomized, controlled trials. ECLIPSE 1 has completed enrollment ahead of the Company’s expectations. Topline results from ECLIPSE 1, 2, and 3 are expected in the first quarter of 2027.