Brii Bio Shares New Data from Phase 2 Chronic Hepatitis B Trials at EASL Congress 2024

Brii Biosciences Limited, a biotechnology firm focused on addressing diseases with significant unmet needs, has released promising new data from two Phase 2 clinical trials involving their therapeutic vaccine, BRII-179, in combination with other treatments for chronic hepatitis B virus (HBV) infection. These findings were presented at the 2024 EASL Congress.

The first study evaluated BRII-179 in combination with BRII-835 (elebsiran), another investigational therapy, observing substantial HBV-specific B and T cell responses in a subset of participants. This immune response correlated with significant reductions in hepatitis B surface antigen (HBsAg) levels, a key marker of HBV infection. Specifically, Pre-S1-specific T cell responses targeting an area near the sodium taurocholate cotransporting polypeptide (NTCP) were associated with high levels of HBsAg reduction. Participants who exhibited this reduction also showed robust anti-HBV neutralizing activity and increased HBsAb induction.

Antonio Bertoletti, MD, from the Duke-NUS Medical School, highlighted the significance of these findings, noting that this study provides direct evidence that BRII-179-induced immune responses can reduce HBsAg and aid viral control in some chronic HBV patients. He emphasized that the vaccine’s ability to enhance anti-HBs antibodies and Pre-S1-specific T cell responses suggests its potential to break immune tolerance, thus contributing to long-term control of HBV.

The second study focused on the use of BRII-179 as an add-on therapy to pegylated interferon-alpha (PEG-IFNα) in chronic HBV patients. This trial revealed that combining BRII-179 with PEG-IFNα significantly improved the sustained HBsAg loss rate beyond the end-of-treatment period, extending up to at least 24 weeks post cessation of nucleos(t)ide reverse transcriptase inhibitors (NRTIs). Data from this double-blind, placebo-controlled trial of 114 virally-suppressed participants showcased that a higher percentage of those treated with BRII-179 and PEG-IFNα maintained HBsAg loss compared to those treated with PEG-IFNα alone. Moreover, participants with higher HBsAb levels at the end of treatment did not experience HBsAg rebound, indicating that effective antibody responses are crucial for sustained off-treatment HBsAg loss.

Safety assessments from the trials noted that the combination therapy of BRII-179 and PEG-IFNα was generally well-tolerated, with no new risks detected during the follow-up period. These encouraging results underscore the potential of BRII-179 as a component of a therapeutic regimen aimed at achieving a functional cure for chronic HBV infection.

BRII-179 is a novel recombinant protein-based HBV immunotherapeutic that aims to induce broad B-cell and T-cell immunity by expressing multiple HBV surface antigens. Originally licensed from VBI Vaccines Inc. in 2018, Brii Bio has expanded its exclusive global rights to BRII-179. Similarly, BRII-835 (elebsiran) is an investigational HBV-targeting siRNA that promotes an effective immune response and exhibits direct antiviral activity.

HBV remains a major global health threat, with over 254 million infected worldwide, leading to significant liver disease and approximately 820,000 annual deaths. China, in particular, bears a high burden with 87 million chronic HBV patients.

Brii Biosciences, listed on the Hong Kong Stock Exchange, is committed to developing innovative therapies for infectious and central nervous system diseases. The company operates in key biotech hubs, including Raleigh-Durham, San Francisco Bay Area, Beijing, and Shanghai.