BRII-B (02137) releases groundbreaking data from the ENSURE II Phase II study at the 2025 AASLD conference.

BRII-B (02137) announced the follow-up results of the ENSURE II Phase II study queue 4 24 weeks after the end of treatment (EOT). These latest data were presented at the American Association for the Study of Liver Diseases (AASLD) Liver Disease Conference held in Washington, D.C. from November 7th to 11th, 2025, and have been concurrently published in the journal "Nature-Medicine". It is reported that ENSURE (NCT05970289) is a multi-center, open-label Phase II study conducted in the Asia-Pacific region. Queue 4 evaluated an innovative sequential combination therapy strategy for hepatitis B virus (HBV) using the company's therapeutic vaccine BRII-179 to activate and enrich the immune response of patients, in order to improve their response to potential functional cure therapy. This queue included participants who had previously received 9 doses of elebsiran in combination with BRII-179 in the Phase II study BRII-179-835-001 (NCT04749368), and they were then treated with elebsiran in combination with PEG-IFN for 48 weeks. Participants were defined as BRII-179 anti-HBs responders or non-responders based on their peak levels of hepatitis B surface antibody (anti-HBs) from previous studies (10 IU/L or <10 IU/L). The latest data show that the benefit of hepatitis B surface antigen (HBsAg) clearance in the BRII-179 responder group was sustained during the follow-up period. At EOT, 58% (11/19) of BRII-179 anti-HBs responders achieved HBsAg clearance. In non-responders to anti-HBs, only 17% (2/12) achieved HBsAg clearance. After 24 weeks post-treatment, 42% (8/19) of anti-HBs responders maintained HBsAg clearance, while only 8% (1/12) of non-responders maintained this status. In the previous BRII-179-835-001 study, 50% (4/8) of anti-HBs responders who continued to have sustained HBsAg clearance after 24 weeks post-EOT had baseline levels of HBsAg between 1,514-3,086 IU/mL, indicating that BRII-179 could induce an anti-HBs response even in patients with higher baseline HBsAg levels. This supports the potential of BRII-179 in improving functional cure outcomes and expanding its applicability in different patient populations. To further clarify the role of BRII-179 in the treatment of HBV infection and optimize combination therapy for key studies, the company is conducting two additional Phase IIb studies. The ENRICH study aims to evaluate the role of BRII-179 in inducing HBV-specific immune responses and/or identifying patients more likely to achieve functional cure. The ENHANCE study consists of two parts: one to evaluate the effectiveness of a triple combination regimen of BRII-179, elebsiran, and PEG-IFN administered concurrently for 48 weeks; the other to explore a sequential approach - first with 24 weeks of treatment with BRII-179 and elebsiran, followed by 24 weeks of triple therapy, while the control group receives 48 weeks of PEG-IFN treatment. Both studies have completed patient recruitment and are expected to announce EOT data in 2026. Dr. David Margolis, Chief Medical Officer of Tengshengbo Medicine, stated, We are pleased to see that the difference in HBsAg clearance rate at EOT has been maintained during the 24-week follow-up. These results support the potential of BRII-179 in achieving faster and more sustained HBsAg clearance and potentially shortening the treatment period with PEG-IFN. We look forward to confirming these findings in the ongoing confirmatory studies.