Brii Bio Presents Late-Breaking Data from Its Phase 2 ENSURE Study at EASL Congress 2026, Further Supporting the Potential Role of BRII-179 in Achieving Durable Immunological Control of HBV

- Final results from the ENSURE study demonstrate that the addition of elebsiran resulted in a higher functional cure rate compared with pegylated interferon alfa ( PEG-IFNα ) alone - Data from Cohort 4 suggested that participants responding to prior BRII-179 treatment achieved the most robust functional cure outcomes, further supporting its potential clinical benefit - Data from an ENSURE translational study demonstrat ed that BRII ‑ 179- induce d epitope-mismatched CD4+ T cell s and HBs ‑ specific B cell maturation were associated with enhanced HBsAg loss following curative treatment, offering additional insight s into its potential mechanisms DURHAM, N.C. and BEIJING, China – May 27 , 2026 – Brii Biosciences Limited (“Brii Bio” or the “Company”, stock code: 2137.HK), a biotechnology company developing therapies to improve patient health and choice across diseases with high unmet medical need, today announced end-of-study (EOS) data from Cohorts 1-4 of its Phase 2 ENSURE study at the European Association for the Study of the Liver (EASL) Congress 2026 in Barcelona, Spain. The ENSURE study (NCT05970289) is a multicenter, open-label Phase 2 study in the Asia-Pacific region. Cohorts 1-3 were designed to evaluate the contribution of elebsiran, an investigational small interfering ribonucleic acid (siRNA), to the combination treatment with PEG-IFNα in participants with chronic hepatitis B virus (HBV) infection with baseline hepatitis B surface antigen (HBsAg) of 100-3,000 IU/mL. Cohort 4 evaluated a novel sequential combination treatment strategy for HBV utilizing Brii Bio’s therapeutic vaccine, BRII-179, to prime and enrich participants with a goal of improving responsiveness to curative therapies. Participants previously treated with 9 doses of BRII-179 and elebsiran in the prior Phase 2 study BRII-179-835-001 (NCT04749368) were enrolled and received 48 weeks of combination treatment with elebsiran and PEG-IFNα. These participants were categorized as BRII-179 anti-HBs responders or non-responders based on whether their peak hepatitis B surface antibody (anti-HBs) titers exceeded 10 IU/L during the prior study. All participants were maintained on nucleos(t)ide analogues (NAs) for an additional 24 weeks upon completion of PEG-IFNα + elebsiran treatment. Functional cure rates at the end of ENSURE study, defined as sustained HBsAg loss with undetectable HBV DNA for at least 24 weeks after stopping all treatment, including NAs, are presented. Final results demonstrated that the HBsAg loss benefit observed in the elebsiran and PEG-IFNα combination cohorts translated into a higher functional cure rate compared to the PEG-IFNα alone cohort. BRII-179-experienced participants achieved higher functional cure rates, particularly among anti-HBs responders, suggesting that BRII-179 may play an important role in achieving durable immunological control of HBV. Brii Bio is conducting two additional Phase 2b trials to further define the role of BRII-179 in the treatment of chronic HBV infection and to optimize combination regimens for pivotal studies. The ENRICH study is evaluating the role of BRII-179 in priming HBV-specific immunity and identifying immuno-responsive patients with a higher likelihood of achieving functional cure. The ENHANCE study consists of two parts: one evaluating concurrent triple combination therapy with BRII-179, elebsiran and PEG-IFNα for 48 weeks, and another evaluating a sequential regimen of BRII-179 and elebsiran for 24 weeks followed by triple combination therapy for 24 weeks. End-of-treatment (EOT) data from both studies are expected to be presented in 2026. “We are encouraged by the consistency of the findings observed throughout the ENSURE study and believe these final results highlight the potential of BRII-179 and elebsiran in improving functional cure outcomes,” said David Margolis, M.D., Chief Medical Officer of Brii Bio. “Together with upcoming data from our ongoing studies, these results provide important insights to guide the future development of our HBV functional cure program.” Details of the late-breaker poster presentation are as follows: Title: Functional cure rate in chronic hepatitis B virus infected participants receiving elebsiran and pegylated interferon alfa: final results from the phase 2 ENSURE study Session/Presentation Type: Late-breaker posters Session Time : May 27, 08:30 - May 30, 16:00 (UTC+1) Abstract N umber /Identifier : LB26-5012/ LBP-040 Presenter: Grace Lai-Hung Wong, MBChB (CUHK), MD (CUHK), FRCP (Lond, Edin), FHKCP, FHKAM (Medicine), Professor of Gastroenterology and Hepatology at CUHK Medical Data Analytics Centre (MDAC) and Department of Medicine and Therapeutics in Hong Kong SAR, China At Week 72 (24 weeks post EOT), 19 of 20 participants who achieved HBsAg loss met NA discontinuation criteria and stopped NA for the additional 24-week follow-up; One participant remained HBeAg positive. In Cohorts 1-3, functional cure was achieved in 2/19 (10.5%) and 3/18 (16.7%) participants from the elebsiran 200 mg or 100 mg + PEG-IFNα cohorts, respectively, compared with 1/18 (5.6%) in the PEG-IFNα cohort. In Cohort 4, functional cure was achieved in 8/31 (25.8%) participants, including 7/19 (36.8%) among anti-HBs responders compared with 1/12 (8.3%) among non-responders. Although all participants achieving functional cure had a baseline HBsAg levels below 1,000 IU/mL in the ENSURE study, 4/7 (57.1%) of anti-HBs responders achieving functional cure had baseline HBsAg levels between 1,154 and 3,086 IU/mL at enrollment in the prior BRII-179-835-001 study. After NA discontinuation, no new treatment-related adverse events (TRAE) were reported. Most TRAEs resolved during the post EOT follow-up period. Participants achieving sustained HBsAg loss through combination therapy demonstrated favorable off-NA outcomes, characterized by infrequent HBV DNA rebound and no ALT elevations. In a separate oral presentation, Dr. Nina Le Bert will report findings from a translational study evaluating immunological responses associated with BRII‑179 using samples from the ENSURE and prior BRII-179-835-001 trials. The study identified a novel mechanism whereby BRII‑179 induced CD4+ T‑cell response targeting epitope sequences in the Pre-S1 region that are mismatched to circulating HBV genotypes. These vaccine‑induced T cells remained functionally stable for over two years, persisted during subsequent PEG-IFNα and siRNA treatment. Notably, these T‑cell responses were associated with progressive maturation of HBs‑specific B cells during treatment, an effect linked to enhanced HBsAg loss rates. These findings provide new insights into the potential mechanisms underlying BRII‑179–mediated functional cure. For more information about Brii Bio’s HBV programs visit www.briibio.com . About Hepatitis B Hepatitis B virus (HBV) infection is one of the world’s most significant infectious disease threats with more than 254 million people infected globally. 1 Chronic HBV infection is the leading cause of liver disease and an estimated 820,000 people die of complications from chronic HBV infection each year. 1 HBV is of exceptional concern in China, where 87 million people are chronically infected. 2 About BRII-179 BRII-179 is a novel recombinant protein-based HBV immunotherapeutic candidate that expresses the Pre-S1, Pre-S2, and S HBV surface antigens, designed to induce enhanced and broad B-cell and T-cell immunity. In November 2023, the Center for Drug Evaluation (the “CDE”) of China’s National Medical Products Administration (the “NMPA”) granted BRII-179 Breakthrough Therapy Designation. About Elebsiran Elebsiran is an investigational subcutaneously administered HBV-targeting siRNA designed to degrade HBV RNA transcripts and limit the production of hepatitis B surface antigen. It has the potential to have direct antiviral activity against HBV and HDV. It is the first siRNA in the clinic to include Enhanced Stabilization Chemistry Plus technology to enhance stability and minimize off-target activity, which potentially can result in an increased therapeutic index. Brii Bio licensed exclusive rights to develop and commercialize elebsiran for the Greater China territory from Vir Biotechnology, Inc. in 2020. In May 2024, the CDE of China’s NMPA granted elebsiran Breakthrough Therapy Designation. About Brii Bio Brii Biosciences Limited (“Brii Bio”, stock code: 2137.HK) is a biotechnology company developing therapies to improve patients’ health by addressing high unmet medical needs with limited treatment options. The Company is advancing a broad pipeline of unique therapeutic candidates with lead programs against hepatitis B virus (HBV) infection. The Company is led by a visionary and experienced leadership team and has operations in both China and the United States. For more information, visit www.briibio.com . Media Inquiries: [email protected] Investor Inquiries: [email protected] Partnering Inquiry: [email protected] --------------------------------- 1 World Health Organization. (April 2024). Global hepatitis report 2024: action for access in low- and middle-income countries. World Health Organization. Retrieved from https://www.who.int/publications/i/item/9789240091672 2 World Health Organization. Hepatitis. World Health Organization. Retrieved from https://www.who.int/china/health-topics/hepatitis#:~:text=There%20are%2087%20million%20people,living%20with%20chronic%20hepatitis%20C. Previous Next [email protected] Home Company Back About Us Back Leadership Back Corporate Executive Team Back Board Of Directors Back Strategic Advisors Back Science Back Our Focus Pipeline Back Infectious Disease Programs Back Literature Archive Back Publications Back Conferences Back Media Back Press Release Back Brii Biosciences Announces Upcoming Conference Participation in November Brii Biosciences Presents Promising Clinical Data to Support Ongoing Development of Novel HIV Therapeutic Candidates at IDWeek 2022 Brii Biosciences to Present New Phase 1 Data from HIV Program at IDWeek 2022 Brii Biosciences Announces Top-line Results from Phase 1 Study of BRII-296, A Long-Acting Therapy in Development for Postpartum Depression Brii Biosciences Announces China Leadership Team Changes Brii Biosciences Appoints Taiyin Yang to Board of Directors, Strengthening Product Quality Oversight to Support Company Momentum Brii Biosciences Announces Upcoming Conference Participation in September Brii Biosciences Provides Corporate Update and Reports 2022 Interim Results WuXi Biologics Announced Exclusive Discovery Research with Brii Biosciences for Novel Bispecific Antibody Immunotherapeutics Brii Biosciences Builds Innovative Pipeline, Forges Public-Private Partnerships to Bring Novel Medicines to Chinese Patients FierceBiotech names Brii Biosciences as one of its “Fierce 15” Biotech Companies of 2018 Brii Biosciences Launches to Bring Innovative Medicines to Chinese Patients VBI Vaccines and Brii Biosciences Initiate Phase 1b/2a Study of BRII-179 (VBI-2601) in Patients with Chronic Hepatitis B Infection Brii Biosciences Expands Infectious Disease Pipeline Brii Biosciences Expands Therapeutic Focus to Include Neurosciences with Addition of John Kraus, M.D., Ph.D. Brii Biosciences Provides Corporate Update on Progress Against Strategic R&D Priorities Brii Biosciences Appoints Rogers Luo, Ankang Li To Leadership Positions Tsinghua University, 3rd People’s Hospital of Shenzhen and Brii Biosciences Establish Partnership to Develop Neutralizing Antibodies Against COVID-19 Brii Biosciences Provides Funding to Columbia University for Research on COVID-19 and Other Coronaviruses Brii Biosciences Antibody Combination Will Not Progress into a Phase 3 Study Evaluating the Treatment of SARS-CoV-2 in Hospitalized Patients Brii Biosciences Closes US$155 Million Series C Financing Brii Biosciences, Vir Biotechnology, and VBI Vaccines Announce Initiation of Phase 2 Clinical Trial of BRII-835 (VIR-2218) in Combination with BRII-179 (VBI-2601) for the Treatment of Hepatitis B Brii Biosciences Monoclonal Antibodies, BRII-196 and BRII-198, Progress to Phase 3 in NIH ACTIV-2 Trial in Ambulatory COVID-19 Patients Brii Biosciences Provides Update on Strategic Clinical Development Progress Brii Biosciences to Present Updated Phase 1b/2a Data on BRII-179 (VBI-2601) in Patients with Chronic Hepatitis B at the International Liver Congress 2021 Brii Biosciences and VBI Vaccines Present Positive Data from Completed Phase 1b/2a Study on BRII-179 (VBI-2601) in Patients with Chronic Hepatitis B at the International Liver Congress 2021 Brii Biosciences Limited Successfully Listed on Main Board of Hong Kong Stock Exchange Brii Biosciences Initiates Phase 2 Clinical Trial in China for Neutralizing Antibodies, BRII-196 and BRII-198, in SARS-CoV-2 Brii Biosciences Announces the Completion of Enrollment in the Phase 3 National Institutes of Health (NIH) ACTIV-2 Trial, Evaluating the BRII-196 and BRII-198 Monoclonal Neutralizing Antibody Combination for the Treatment of COVID-19 Brii Biosciences Announces Positive Data from the Phase 3 ACTIV-2 Trial Evaluating Combination BRII-196 and BRII-198 in Non-Hospitalized COVID-19 Patients Brii Biosciences Adds US$100 Million to Advance its Late-Stage Monoclonal Antibody Combination Therapy, BRII-196/BRII-198, for Non-Hospitalized COVID-19 Patients Brii Bio Appoints Coy Stout as Senior Vice President and Head of U.S. Market Access and Patient Advocacy Brii Bio Initiates Submission of Emergency Use Authorization Filing to U.S. FDA for BRII-196/BRII-198, its Monoclonal Antibody Combination Therapy for Non-Hospitalized COVID-19 Patients at High Risk of Clinical Progression to Severe Disease Brii Bio Presents Positive Phase 3 Data on BRII-196/BRII-198, the Company’s SARS-CoV-2 Monoclonal Neutralizing Antibody Combination Therapy, in an Oral Late-Breaker Presentation at IDWeek 2021 Brii Biosciences Announces Upcoming Participation at November Conferences Brii Bio Receives the BioCentury-BayHelix R&D Achievement of the Year Award at the 2021 BioCentury China Healthcare Summit Brii Biosciences Joins Hang Seng Composite Index Brii Biosciences Included in Hong Kong Stock Connect Brii Bio Announces Amubarvimab/Romlusevimab Combination Received Approval from NMPA as First COVID-19 Neutralizing Antibody Combination Therapy in China Brii Biosciences Receives Clinical Hold Notification from US. FDA on BRII-732 Brii Bio Announces Amubarvimab/Romlusevimab Combination Retains Neutralizing Activity Against Omicron SARS-CoV-2 Variant Brii Bio Doses First Patient in Phase 2a/2b Clinical Trial of BRII-179 (VBI-2601) for the Functional Cure of Chronic Hepatitis B Brii Biosciences Appoints Eleanor de Groot as Chief Technology Officer and Aleksandar Skuban as Central Nervous System Diseases Therapy Area Head Brii Biosciences Announces Positive Data Demonstrating its Long-Acting COVID-19 Neutralizing Antibody Therapy, Amubarvimab/Romlusevimab Combination, Retains Neutralizing Activity Against Live Omicron Virus BA.4/5 and BA.2.12.1 Subvariants Brii Bio Announces Strategic Partnership with China Resources Pharmaceutical Commercial Group to Advance the Commercialization of Long-acting COVID-19 Neutralizing Antibody Therapy, Amubarvimab/Romlusevimab Combination, in China Brii Biosciences Appoints Dr. Susannah Cantrell as Chief Business Officer Brii Biosciences Announces Commercial Launch of its Amubarvimab/Romlusevimab Combination Therapy for COVID-19 in China Brii Biosciences Exercises Option for Vir Biotechnology’s VIR-3434, a Broadly Neutralizing Monoclonal Antibody Targeting Hepatitis B in Greater China Brii Biosciences Announces Upcoming Conference Participation in July Brii Biosciences Announces Positive Data from a Randomized, Single-Blind Study of its Long-Acting COVID-19 Neutralizing Antibody Therapy, Amubarvimab/Romlusevimab Combination, in China Brii Bio Announces GMP Compliance Inspection Result for the Amubarvimab Injection and Romlusevimab Injection Brii Biosciences Announces Upcoming Conference Participation in June Brii Biosciences to be Added to MSCI China Small Cap Index Brii Bio Announces Positive Data Demonstrating its Long-Acting COVID-19 Neutralizing Antibody Therapy, Amubarvimab/Romlusevimab Combination, Retains Neutralizing Activity Against Omicron BA.2 Subvariant Brii Bio Reports Progress on ESG Commitments in Its Inaugural ESG Report Brii Biosciences Announces Upcoming Participation at May Conference Brii Biosciences Announces Upcoming Participation at April Conferences Brii Bio Presents New Data on BRII-835 (VIR-2218) in Chinese Patients with Chronic Hepatitis B at APASL 2022 Brii Bio Announces Strategic Partnership with Sinopharm to Advance Commercialization of Long-Acting COVID-19 Neutralizing Antibody Therapy, Amubarvimab/Romlusevimab Combination, in China Brii Biosciences Provides Corporate Update and Reports Full Year 2021 Financial Results Brii Bio to Present Phase 2 Data on Two Monthly Doses of BRII-835 (VIR-2218) in Chinese Patients with Chronic Hepatitis B at APASL 2022 Brii Bio Announces that National Health Commission of China Adds Amubarvimab/Romlusevimab Combination to its COVID-19 Diagnosis and Treatment Guidelines (9th Pilot Edition) Brii Biosciences Announces Upcoming Participation at March Conferences Brii Bio Appoints Karen D. Neuendorff as Chief People Officer and Head of Human Resources Brii Biosciences Announces Upcoming Conference Participation in January Brii Biosciences Provides Update on Strategic Clinical Development Progress Brii Biosciences Announces Interim Results from Phase 2 Study Evaluating Combination BRII-835 and BRII-179 in Development for HBV Functional Cure Press Release Press Release Press Release Press Release Press Release Press Release Press Release Press Release Press Release Press Release Press Release Press Release Press Release Press Release Press Release Press Release Press Release Press Release Press Release Press Release Press Release Press Release Press Release Press Release Press Release Press Release Press Release Press Release Press Release Press Release Press Release Press Release Press Release Press Release Press Release Press Release Press Release Press Release Press Release Press Release Press Release Press Release Press Release Media Reports Back Investor Relations Back Fact Sheet Corporate Governance Back Board of Directors Back Committee Composition Back Corporate Governance Documents Back Listing Documents Back Announcements & Circulars Share Graph Financial Calendar Presentation & Webcast Back Webcasts Back Presentations Back Financial Reports IR Enquiries & Email Alert Replacement of Lost Share Certificates Back People Back Culture Benefits Back Meet Our Team Opportunities Contact Us © 2026 Brii Biosciences. All Rights Reserved. | Developed by Euroland IR Recruitment Scam Warning Privacy Statement Terms of Use This website uses cookies and similar technologies, to enhance your browsing experience and provide personalized recommendations. By continuing to use this website, you agree to the use of cookies and similar technologies as described in our Privacy Policy Accept

The release as fetched from its publisher. briibio.com ↗