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 of tobevibart and elebsiran for the treatment of chronic hepatitis delta (CHD). This decision follows the FDA's fast track designation and is based on encouraging preliminary data from the Phase 2 SOLSTICE trial.
The 24-week data from the Phase 2 SOLSTICE trial was presented at AASLD The Liver Meeting in San Diego, CA. An investor conference call is scheduled to discuss the results further.
The Urgent Need for New Therapies in Chronic Hepatitis Delta
Chronic hepatitis delta (CHD) is a severe liver disease caused by the hepatitis delta virus (HDV). It is considered the most aggressive form of chronic viral hepatitis, often leading to cirrhosis and liver failure within 5 years of infection. Currently, there is no approved treatment in the United States, and treatment options are limited in the European Union and globally.
"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."
Orphan Drug Designation: Benefits and Implications
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 Details
The SOLSTICE trial is a Phase 2 study evaluating the safety, tolerability, and efficacy of tobevibart, alone or in combination with elebsiran, in patients with chronic hepatitis delta. It is a multi-center, open-label, randomized study. Primary endpoints include the proportion of participants with undetectable hepatitis delta virus (HDV) RNA (defined as HDV RNA equal to or greater than 2 log10 decrease from baseline or below the limit of detection) up to week 24, alanine aminotransferase (ALT) normalization (defined as ALT below the upper limit of normal) up to week 24, and treatment-emergent adverse events (TEAEs) and serious adverse events (SAEs) up to 118 weeks. Secondary endpoints include the proportion of participants with undetectable HDV RNA at different time points and up to 192 weeks. More information about this trial can be found at clinicaltrials.gov (NCT05461170).
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. It is administered subcutaneously and is currently in clinical development for treating patients with chronic hepatitis B and chronic hepatitis delta.
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 currently in clinical development for treating patients with chronic hepatitis B and chronic hepatitis delta. It is the first asset in Vir Biotechnology’s collaboration with Alnylam Pharmaceuticals, Inc. to enter clinical studies.
