Vir Biotechnology Presents Positive Chronic Hepatitis Delta Clinical Trial Data and Announces Initiation of Phase 3 Registrational Program

– Monthly tobevibart and elebsiran combination achieves rapid 100% virologic suppression at Week 24, sustained through Week 60 –

– Undetectable HDV RNA in 41% of participants at Week 24, increasing to 64% by Week 36 and up to 80% by Week 60 across cohorts –

– Combination well-tolerated: no treatment-related severe AEs, treatment-related discontinuations or ALT flares –

– Following a recent FDA meeting, Phase 3 ECLIPSE registrational program to begin in the first half of 2025 –

– New data presented at AASLD The Liver Meeting. Investor conference call November 19, 2024, at 5.15 a.m. PT / 8.15 a.m. ET –

SAN FRANCISCO--(BUSINESS WIRE)-- Vir Biotechnology, Inc. (NASDAQ:VIR) today announced positive results from the SOLSTICE Phase 2 clinical trial evaluating tobevibart alone, or in combination with elebsiran, in people with chronic hepatitis delta (CHD). The most-advanced and potential first-of-its-kind investigational human monoclonal antibody and siRNA combination dosed monthly achieved 100% virologic response and rapid hepatitis delta virus (HDV) RNA suppression. HDV RNA below the lower limit of quantification (< LLOQ), target not detected (TND), the best measure that the virus is cleared from the body, was achieved in 41% (13/32) of participants at Week 24 rising to 64% (14/22) of participants by Week 36. In a cohort that reached Week 60, 80% (4/5) achieved HDV RNA TND.

These data were presented in an oral session at the American Association for the Study of Liver Diseases (AASLD) The Liver Meeting®, in San Diego, CA. Based on these results, and following a recent meeting with the FDA, Vir Biotechnology plans to initiate the Phase 3 registrational ECLIPSE program in the first half of 2025 to further evaluate the combination of tobevibart and elebsiran for the treatment of CHD.

CHD is a chronic inflammatory liver disease caused by HDV1. It is the most severe form of chronic viral hepatitis2 and on average, people living with CHD will progress to cirrhosis and liver failure within 5 years3. There is no approved treatment in the United States. The objective of therapy is to clear the virus, and combination therapy offers the potential to do so by tackling the viral lifecycle through multiple mechanisms.

“Achieving HDV RNA suppression with a safe, well-tolerated, and conveniently dosed treatment could be transformative for people living with hepatitis delta. The impressive rates of virologic suppression seen in the SOLSTICE Phase 2 data suggest that tobevibart and elebsiran have the potential to significantly improve patient outcomes,” 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. “New, effective therapeutic options are urgently needed, and I am excited to see this combination advance into a registrational Phase 3 program.”

Primary Endpoint Analysis from the Phase 2 SOLSTICE Trial

Clinical trial participants were randomized to receive tobevibart 300 mg monotherapy every two weeks (n=33) or a combination of tobevibart 300 mg and elebsiran 200 mg every four weeks (combination de novo arm, n=32). In addition, the participants from previous tobevibart or elebsiran monotherapy cohorts could rollover to receive the combination of tobevibart 300 mg and elebsiran 200 mg every four weeks (combination rollover, n=13). Rates of virologic suppression were evaluated at Week 24, and further assessed at Weeks 36, 48 and 60 in those participants that had reached each timepoint. Further monitoring will continue up to 192 weeks.

Rapid and Sustained Virologic Suppression – 100% of participants across combination arms achieved an HDV RNA ≥2 log10 decrease or below limit of detection (LOD) at Week 24, and this rate was sustained over time in all participants at Weeks 36 (22/22) and those in the rollover cohort that reached Week 60 (5/5).

HDV RNA TND was achieved in 41% (13/32) of participants across combination arms at Week 24 and this rose to 64% (14/22) at Week 36. By week 60, this had risen further with 80% (4/5) of participants in the rollover cohort having achieved no detectable viral RNA.

Approximately 90% of participants receiving the combination achieved reductions in hepatitis B surface antigen (HBsAg) values below