Brii Biosciences Receives Two Breakthrough Therapy Designations for BRII-877 and BRII-835

Brii Biosciences Limited, a biotechnology firm listed under the stock code 2137.HK, has recently achieved significant progress in its endeavor to combat hepatitis B virus (HBV) and hepatitis D virus (HDV). The Center for Drug Evaluation (CDE) of the National Medical Products Administration (NMPA) has granted Breakthrough Therapy Designations to two of Brii Bio's investigational treatments: BRII-877 (tobevibart), a broadly neutralizing monoclonal antibody targeting HBV, and BRII-835 (elebsiran), a small interfering ribonucleic acid (siRNA) targeting HBV.

This milestone follows the earlier Breakthrough Therapy Designation awarded to BRII-179, an HBV immunotherapeutic, in November 2023. The designation for BRII-877 is based on Phase 1 and 2 studies performed by Vir Biotechnology and Brii Bio. To date, over 350 individuals with HBV have been treated with BRII-877, demonstrating its tolerability and significant reductions in HBsAg levels, which are indicative of its potential efficacy in treating chronic HBV and HDV infections. Similarly, the designation for BRII-835 is supported by clinical trials showing positive outcomes in over 570 participants. These studies revealed that BRII-835 was well-tolerated and exhibited direct antiviral activity against HBV.

Dr. Qing Zhu, Brii Bio's Head of China R&D, emphasized that these designations validate the company's scientific approach in developing combination regimens aimed at achieving a functional cure for chronic HBV. The clinical trials over the past five years have provided Brii Bio and its partner Vir Biotechnology with extensive safety and efficacy data, which will guide their late-stage development plans.

With three breakthrough therapeutic modalities under its belt, Brii Bio is well-positioned to address a wide range of HBV infections, including those co-infected with HDV. The company aims to initiate multiple combination studies in 2024 to fine-tune these curative regimens, which will play a crucial role in its registration strategy to deliver the most effective treatments to HBV patients.

Hepatitis B is a major global health issue, affecting over 254 million people worldwide and leading to severe liver diseases and fatalities. In China alone, 87 million individuals are infected with HBV. Hepatitis D, which depends on HBV for replication, is the most severe form of chronic viral hepatitis, leading to rapid progression to liver cancer and death. Nearly 5% of chronic HBV cases are complicated by HDV co-infection.

BRII-877 (tobevibart) is an investigational monoclonal antibody designed to prevent HBV and HDV from entering liver cells and reduce viral particles in the blood. It incorporates Xencor's Xtend™ and other Fc technologies, potentially functioning as a T-cell vaccine and extending its half-life. Brii Bio acquired exclusive rights to develop and commercialize BRII-877 in greater China from Vir Biotechnology.

BRII-835 (elebsiran) is an investigational siRNA targeting HBV, designed to stimulate an immune response and directly combat HBV and HDV. It utilizes Enhanced Stabilization Chemistry Plus (ESC+) technology to enhance stability and reduce off-target effects, potentially increasing its therapeutic index. Brii Bio licensed exclusive rights to BRII-835 from Vir Biotechnology in 2020.

BRII-179 is an innovative protein-based HBV immunotherapeutic that expresses multiple HBV surface antigens, designed to induce broad B-cell and T-cell immunity. Brii Bio licensed BRII-179 from VBI Vaccines and extended its exclusive license to global rights in July 2023.

Brii Biosciences Limited is committed to developing therapies to address significant public health challenges, focusing on infectious and central nervous system diseases. The company operates in major biotech hubs, including Raleigh-Durham, San Francisco Bay Area, Beijing, and Shanghai.