Vir Biotechnology, Inc. (Nasdaq: VIR) has announced positive end-of-treatment data from Part B of the MARCH Phase 2 clinical study, evaluating combinations of tobevibart and elebsiran, with or without pegylated interferon alfa (PEG-IFN), in participants with chronic hepatitis B. The study's results indicate promising rates of hepatitis B surface antigen (HBsAg) loss (seroclearance) in participants with low baseline HBsAg levels.
The MARCH study is a Phase 2 trial designed to assess the safety and efficacy of tobevibart and elebsiran, both individually and in combination, for the treatment of chronic hepatitis B. Part B of the study specifically investigated the combination of tobevibart and elebsiran, with or without the addition of PEG-IFN, to determine if a synergistic effect could be achieved in reducing HBsAg levels and potentially leading to functional cures.
Hepatitis B is a significant global health concern, with millions of people chronically infected worldwide. Current treatments often require long-term management and do not always result in a functional cure, which is characterized by sustained HBsAg loss. The development of new therapies that can achieve higher rates of functional cure is a critical unmet need.
The data presented by Vir Biotechnology highlights the potential of tobevibart and elebsiran as a combination therapy to address this need. While detailed results and statistical significance were not provided in the initial announcement, the company indicated that the observed HBsAg seroclearance rates in patients with low baseline HBsAg were promising. Further analysis and follow-up will be necessary to fully evaluate the durability of the response and the long-term clinical benefits.
Tobevibart is a monoclonal antibody designed to neutralize hepatitis B virus (HBV) and reduce viral load, while elebsiran is an siRNA therapeutic that targets the production of HBsAg. The combination of these two agents aims to provide a dual mechanism of action, suppressing viral replication and reducing the levels of circulating viral antigens. This approach could potentially lead to immune reconstitution and sustained control of HBV infection.
