Brii Bio Shares New Phase 2 Chronic Hepatitis B Trial Data

Brii Biosciences Limited, a biotechnology company focused on developing innovative therapies for diseases with significant unmet needs, recently unveiled new data from two Phase 2 clinical trials involving BRII-179 at the EASL™ Congress 2024 in Durham, N.C. and Beijing. BRII-179, a novel therapeutic vaccine, was evaluated either in combination with BRII-835 (elebsiran) or as an adjunctive treatment to pegylated interferon-alpha (PEG-IFNα) for chronic hepatitis B virus (HBV) infection.

In one of the Phase 2 trials, BRII-179 combined with BRII-835 showed promising results. The combination induced strong HBV-specific B and T cell responses, which correlated with antiviral effects in some participants. This was the first direct evidence linking immune responses induced by an HBV therapeutic vaccine to HBsAg reduction and viral control. Professor Antonio Bertoletti from Duke-NUS Medical School highlighted that the antiviral activity appeared to be associated with an increase in anti-HBs antibodies and Pre-S1-specific T-cell responses, suggesting that BRII-179 could effectively break immune tolerance and help in controlling the viral infection.

Another critical finding came from a Phase 2 trial where BRII-179 was administered on top of PEG-IFNα. The results showed an improvement in the overall HBsAg loss rate from the end of treatment to at least 24 weeks post nucleos(t)ide reverse transcriptase inhibitors (NRTI) discontinuation when compared to the PEG-IFNα group alone. The study was carried out in a randomized, double-blind, placebo-controlled environment with 114 participants who were virally suppressed due to chronic HBV infection.

These studies emphasize the potential of BRII-179 to be a significant component in combination therapies for chronic HBV, potentially leading to a functional cure. The favorable benefit-risk profile shown in these trials supports further clinical evaluations, particularly in combinations with other treatment modalities like siRNA and PEG-IFNα.

BRII-179 is a recombinant protein-based HBV immunotherapeutic candidate that expresses multiple HBV surface antigens (Pre-S1, Pre-S2, and S). It aims to induce a broad B-cell and T-cell immunity. Brii Bio obtained the license for BRII-179 from VBI Vaccines, Inc. in December 2018 and expanded it to global rights in July 2023.

BRII-835 (elebsiran) is an investigational HBV-targeting siRNA administered subcutaneously. It has shown potential to elicit an effective immune response and has direct antiviral activity against both HBV and HDV. Notably, BRII-835 is the first siRNA in clinical trials to incorporate Enhanced Stabilization Chemistry Plus (ESC+) technology, designed to improve stability and minimize off-target effects, potentially increasing its therapeutic index. Brii Bio secured exclusive rights to develop and commercialize BRII-835 for greater China from Vir Biotechnology, Inc. in 2020.

Hepatitis B is a major global health issue with over 254 million people infected, leading to severe liver disease and approximately 820,000 annual deaths. China is particularly affected, with 87 million people suffering from chronic HBV infection.

Brii Biosciences Limited is dedicated to developing therapies that address pressing public health challenges, especially in areas with high unmet medical needs and limited treatment options. The company focuses on infectious and central nervous system diseases, with a robust pipeline of unique therapeutic candidates. Led by an experienced leadership team, Brii Bio operates in key biotech hubs, including Raleigh-Durham, the San Francisco Bay Area, Beijing, and Shanghai.