Vir hepatitis delta combination meets Phase 3 primary endpoint

Vir Biotechnology's monthly elebsiran and tobevibart combination met the primary endpoint of its pivotal Phase 3 ECLIPSE 1 trial in chronic hepatitis delta, with 44 percent of treated patients reaching undetectable virus plus liver enzyme normalisation at week 48 against none in the delayed treatment arm.

Why it matters: Chronic hepatitis delta is the most severe form of viral hepatitis and has limited approved treatments, so a positive pivotal trial puts Vir on a path toward a United States filing planned for mid 2027.

Data as of Vir Biotechnology press release of November 8, 2026, via Business Wire, read in full in this run; figures are company reported topline results presented at the AASLD Liver Meeting on November 8, 2026, and the full dataset has not been published. Endpoints News reported the same result on November 8, 2026. Developing item.

Vir Biotechnology said its Phase 3 ECLIPSE 1 trial of elebsiran plus tobevibart in chronic hepatitis delta met its primary endpoint, with 44 percent of patients on the monthly combination reaching undetectable hepatitis delta virus RNA plus ALT normalisation at week 48, against 0 percent in the delayed treatment arm (p below 0.0001). The key secondary endpoint was also met, with 79 percent of treated patients reaching undetectable virus, and all treated patients achieved a virologic response by week 24.

The trial enrolled 124 patients randomised 2 to 1 against delayed treatment. Vir said the regimen was well tolerated, with one Grade 3 treatment related adverse event, a neutrophil count decrease that resolved in 15 days, and no treatment interruptions or discontinuations. Data from the ECLIPSE 2 and ECLIPSE 3 trials are expected in the first quarter of 2027, and Vir plans a United States FDA submission in mid 2027; the regimen already holds FDA Breakthrough Therapy and Fast Track designations.

Vir hepatitis delta combination meets Phase 3 primary endpoint

Sources