Vir Biotechnology has received a positive opinion from the European Medicines Agency (EMA) Committee for Orphan Medicinal Products (COMP) for its application for orphan drug designation for tobevibart and elebsiran in the treatment of chronic hepatitis delta (CHD). This regulatory milestone follows promising preliminary data from the Phase 2 SOLSTICE trial and highlights the potential of this combination therapy to address a critical gap in hepatitis delta care.
The positive opinion from the EMA COMP is based on encouraging preliminary data from the Phase 2 SOLSTICE trial. The 24-week data from the trial is scheduled to be presented at AASLD The Liver Meeting. This regulatory progress comes on the heels of the U.S. Food and Drug Administration (FDA) granting fast track designation to tobevibart and elebsiran in June 2024, underscoring the growing recognition of the potential of this therapeutic approach.
Addressing a Critical Unmet Need in Hepatitis Delta
Chronic hepatitis delta is considered the most aggressive form of chronic viral hepatitis, often leading to cirrhosis and liver failure within 5 years of infection. Currently, there are limited treatment options available in the European Union and globally, and no approved treatment exists in the United States. The orphan drug designation is reserved for medicines intended to treat rare, life-threatening, or chronically debilitating conditions where no satisfactory treatment option is available, or where the medicine can be of significant benefit to those affected by a specific condition.
According to Mark Eisner, M.D., M.P.H., Executive Vice President and Chief Medical Officer at Vir Biotechnology, "Chronic hepatitis delta dramatically raises the risk of severe liver disease, including cancer, and eventually death, so new therapeutic options are urgently needed. 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."
Implications of Orphan Drug Designation
The European Commission will now evaluate the COMP’s positive opinion and consider tobevibart and elebsiran for orphan drug designation. If granted, this designation would provide Vir Biotechnology with special incentives in the EU, including access to specific scientific advice, fee reductions, and 10 years of market exclusivity once the medicine is approved.
About the SOLSTICE Trial
The SOLSTICE trial is a Phase 2 multi-center, open-label, randomized study designed to evaluate 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 (defined as HDV RNA equal to or greater than a 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. 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. Current data indicates that it has the potential to have direct antiviral activity against hepatitis B virus and hepatitis delta virus.
