Tobevibart and elebsiran, developed by Vir Biotechnology for chronic hepatitis delta (CHD), have received Breakthrough Therapy designation from the U.S. FDA and Priority Medicines (PRIME) designation from the EMA. These designations are based on positive safety and efficacy data from the Phase 2 SOLSTICE trial, showing the drug combination’s potential to significantly suppress the hepatitis delta virus. Vir Biotechnology plans to initiate the Phase 3 ECLIPSE registrational program in the first half of 2025.
These designations are crucial for CHD patients who currently face a dire prognosis. CHD is the most severe form of viral hepatitis, leading to increased risks of liver cancer, cirrhosis, and liver failure, often within five years of infection. Currently, there are no approved treatments in the U.S. and limited options globally. The Breakthrough Therapy and PRIME designations acknowledge the potential of tobevibart and elebsiran to address this critical unmet medical need, offering hope for improved outcomes and potentially extending survival for CHD patients. The expedited development and review processes associated with these designations could significantly reduce the time it takes for these potentially life-saving therapies to become available.
The Phase 2 SOLSTICE trial evaluated the safety, tolerability, and efficacy of tobevibart, both alone and in combination with elebsiran. The primary endpoints included the proportion of participants with undetectable HDV RNA, ALT normalization, and adverse events. Data presented at AASLD The Liver Meeting® demonstrated compelling efficacy in suppressing the virus, suggesting the combination could dramatically alter the course of CHD. Tobevibart, a monoclonal antibody, targets the hepatitis B surface antigen, inhibiting viral entry into liver cells. Elebsiran, a siRNA, degrades hepatitis B virus RNA, limiting the production of the surface antigen. Both therapies are administered subcutaneously.
The Breakthrough Therapy and PRIME designations, coupled with the earlier Fast Track designation and positive opinion on orphan drug designation, underscore the significance of this drug combination. These designations facilitate a more efficient regulatory pathway, potentially accelerating the availability of tobevibart and elebsiran to patients who desperately need effective treatment options. This development sets the stage for a pivotal Phase 3 trial that could ultimately transform the treatment landscape for CHD and offer a new standard of care for this debilitating disease. The anticipated commencement of the Phase 3 ECLIPSE program in the first half of 2025 represents a significant milestone in the fight against CHD.
Jon Napitupulu is Director of Media Relations at The Clinical Trial Vanguard. Jon, a computer data scientist, focuses on the latest clinical trial industry news and trends.
