Brii Biosciences Showcases Promising Phase 2 ENSURE Study Data at AASLD 2025

Promising Developments in Hepatitis B Treatment

In a significant advancement for Hepatitis B treatment, Brii Biosciences Limited recently presented compelling long-term data from its ongoing Phase 2 ENSURE study during the American Association for the Study of Liver Diseases (AASLD) 2025 conference held in Washington D.C. From November 7-11, 2025, the company detailed findings that reinforce the potential of their therapeutic vaccine, BRII-179, as a curative option for patients with chronic Hepatitis B.

Study Overview

The ENSURE study, identified as NCT05970289, is a multi-center, open-label Phase 2 investigation taking place across the Asia-Pacific region. Designed to assess a novel sequential treatment strategy, the study employs BRII-179 in conjunction with elebsiran and pegylated interferon alfa (PEG-IFNα) to evaluate their combined effectiveness against the Hepatitis B virus (HBV).

The data presented at AASLD highlights findings from Cohort 4, following participants who previously received nine doses of elebsiran. These individuals transitioned to a combination treatment phase lasting 48 weeks, with results illustrating a stark contrast in HBsAg loss between BRII-179 anti-HBs responders and non-responders—58% vs. 17% at end of treatment.

Sustained Outcomes at 24 Weeks Post-Treatment

The follow-up results at 24 weeks post end of treatment (EOT) are particularly notable. Among BRII-179 anti-HBs responders, 42% maintained loss of HBsAg, which underlines the durability of this treatment strategy. This suggests that BRII-179 has the potential to not only induce a quicker response to treatment but also to maintain that response over time. Interestingly, even participants with initially higher baseline HBsAg levels demonstrated robust anti-HBs responses, further supporting the hypothesis that BRII-179 can deliver functional cure prospects across diverse patient populations.

Moreover, Dr. David Margolis, Chief Medical Officer of Brii Bio, expressed optimism regarding these findings, stating, "The sustained difference in HBsAg seroclearance rates post EOT indicates that BRII-179 may allow for a shorter treatment duration with PEG-IFNα, ultimately improving patient's treatment experience."

Future Research Directions

Brii Biosciences is actively pursuing further insights through additional Phase 2b trials. The ongoing ENRICH study seeks to evaluate how BRII-179 can prime HBV-specific immune responses while the ENHANCE study will assess the efficacy of various combinations of BRII-179 with other treatments. Both studies have reached full enrollment, with expected EOT data results slated for presentation in 2026.

Addressing a Major Global Health Challenge

Hepatitis B remains a critical public health concern, affecting over 254 million people globally, according to the World Health Organization. The chronic infection contributes significantly to liver disease, culminating in approximately 820,000 deaths annually. This is particularly pressing in China, where an estimated 87 million individuals live with chronic HBV infection. Given these statistics, the innovative approaches investigated by Brii Biosciences are timely and essential.

About Brii Biosciences

Brii Biosciences Limited, listed under the stock code 2137.HK, is dedicated to developing therapies aimed at addressing major public health issues where there are significant unmet medical needs. Their focus primarily lies on infectious diseases, with a robust pipeline targeting Hepatitis B. By leveraging a combination of novel therapeutic candidates and a strong leadership team, Brii Bio continues to position itself as a leader in the biotechnology sector.

Conclusion

The data from the ENSURE study presented at AASLD 2025 paints a hopeful picture regarding the future of chronic Hepatitis B treatment. As upcoming studies aim to validate these findings, BRII-179 may well usher in a new era for HBV management, offering patients not just treatment, but the prospect of a cure. With ongoing research and innovative strategies in the works, the fight against Hepatitis B is gaining momentum—one study at a time.