Vir Biotechnology announced that the European Medicines Agency (EMA) Committee for Orphan Medicinal Products (COMP) has issued a positive opinion on the application for orphan drug designation for tobevibart and elebsiran for the treatment of chronic hepatitis delta (CHD). This decision underscores the potential of the combination therapy to address a critical unmet need in CHD, a severe and progressive liver disease. The announcement coincides with the presentation of 24-week data from the Phase 2 SOLSTICE trial at AASLD The Liver Meeting.
CHD is caused by the hepatitis delta virus (HDV) and is considered the most aggressive form of chronic viral hepatitis. Patients often progress to cirrhosis and liver failure within five years of infection. Currently, there is no approved treatment in the United States, and treatment options are limited in the European Union and globally.
Addressing Unmet Needs in Hepatitis Delta
"Chronic hepatitis delta dramatically raises the risk of severe liver disease, including cancer, and eventually death, so new therapeutic options are urgently needed," said Mark Eisner, M.D., M.P.H., Executive Vice President and Chief Medical Officer, Vir Biotechnology. "The COMP’s positive opinion on tobevibart and elebsiran reflects the potential of this combination to address a critical gap in hepatitis delta care. Our clinical data to date has been encouraging, suggesting that this approach could meaningfully improve outcomes for patients living with this devastating disease."
The European Commission will evaluate the COMP’s positive opinion and consider tobevibart and elebsiran for orphan drug designation. This designation is for medicines intended to treat rare, life-threatening, or chronically debilitating conditions where no other satisfactory treatment option is available, or where the medicine can be of significant benefit to those affected by a specific condition. The designation provides special incentives in the E.U., including access to specific scientific advice, fee reductions, and 10 years of market exclusivity once the medicine is approved.
SOLSTICE Trial and Regulatory Pathways
The Phase 2 SOLSTICE trial is a multi-center, open-label, randomized study evaluating the safety, tolerability, and efficacy of tobevibart, alone or in combination with elebsiran, in patients with chronic hepatitis delta. Primary endpoints include the proportion of participants with undetectable hepatitis delta virus (HDV) RNA and alanine aminotransferase (ALT) normalization up to week 24.
In June 2024, the U.S. Food and Drug Administration (FDA) granted fast track designation for the combination of tobevibart and elebsiran for the treatment of CHD. This designation is intended to facilitate the development and expedite the review of drugs to treat serious conditions and fill an unmet medical need.
About Tobevibart and Elebsiran
Tobevibart is an investigational, broadly neutralizing monoclonal antibody targeting the hepatitis B surface antigen. It 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 has been engineered to have an extended half-life and is administered subcutaneously.
Elebsiran is an investigational, hepatitis B virus-targeting small interfering ribonucleic acid (siRNA) designed to degrade hepatitis B virus RNA transcripts and limit the production of hepatitis B surface antigen. It has the potential to have direct antiviral activity against hepatitis B virus and hepatitis delta virus. Elebsiran is administered subcutaneously and is the first asset in Vir Biotechnology’s collaboration with Alnylam Pharmaceuticals, Inc. to enter clinical studies.
