BRII-B (02137) presented the latest breakthrough data from the ENRICH and ENHANCE Phase II studies at the 2026 AASLD Annual Meeting

BRII-B (02137) announced that the company presented the end-of-treatment (EOT) and follow-up results from its Phase IIb ENRICH and ENHANCE studies in three late-breaking oral presentations at the American Association for the Study of Liver Diseases (AASLD) Liver Meeting, held November 5-9, 2026, in Denver, Colorado, USA. The latest results further enrich the data accumulated across five Phase II studies of BRII-179. In particular, the ENSURE, ENRICH, and ENHANCE studies, through a progressively layered study design, further evaluated the potential of BRII-179 to activate HBV-specific immune responses and enrich for participants with immune-responsive characteristics, and provided a basis for the design of combination treatment regimens aimed at achieving durable hepatitis B surface antigen (HBsAg) clearance and functional cure. The potential immune activation and enrichment effects of BRII-179 were first observed in ENSURE study Cohort 4: participants who had received BRII-179 treatment showed higher functional cure rates, especially those who developed hepatitis B surface antibody (anti-HBs) responses. The ENRICH study subsequently prospectively evaluated this strategy: participants first received 12 weeks of BRII-179 treatment (dosed every 3 weeks or every 2 weeks), followed by elebsiran and pegylated interferon alpha (PEG-IFN) treatment. Across the two BRII-179 dosing regimens in the ENRICH study, 41.9% of participants achieved HBsAg clearance at EOT, and 32.4% of participants maintained HBsAg clearance 24 weeks after EOT; both results were consistent with the observations in ENSURE study Cohort 4. The ENHANCE study further evaluated how to incorporate BRII-179 into a triple regimen consisting of BRII-179, elebsiran, and PEG-IFN. In Part A1, concurrent triple therapy with BRII-179, elebsiran, and PEG-IFN achieved higher HBsAg clearance rates at EOT than PEG-IFN monotherapy (25.5% and 10.2%, respectively), and this trend was maintained through 24 weeks after EOT (17.3% and 6.1%, respectively). Part A2 of the ENHANCE study evaluated a sequential combination strategy, in which BRII-179 plus elebsiran was first administered for 24 weeks of immune activation, followed by elebsiran plus PEG-IFN with the treatment course shortened to 24 weeks. At EOT, 22.5% of participants achieved HBsAg clearance. Among participants who developed anti-HBs responses after BRII-179 plus elebsiran immune activation (defined as anti-HBs 10 IU/L at Week 24), HBsAg clearance rates at EOT were higher than in non-responders (30.6% and 15.9%, respectively). At 8 weeks after EOT, the overall HBsAg clearance rate among participants rose further to 25.0%, and the HBsAg clearance rate among anti-HBs responders rose to 33.3%. These results further reveal the immune-activating effect of BRII-179 and its potential to improve responses to subsequent siRNA and PEG-IFN combination therapy. Both the ENRICH and ENHANCE studies observed encouraging HBsAg clearance rates among participants with higher baseline HBsAg levels. In the ENRICH study, among participants with baseline HBsAg levels above 1,000 IU/mL and no more than 3,000 IU/mL, 32.1% achieved HBsAg clearance at EOT, and 20.8% maintained HBsAg clearance 24 weeks after EOT. In Part A1 of the ENHANCE study, among participants with baseline HBsAg levels above 1,000 IU/mL, those receiving triple therapy had HBsAg clearance rates of 24.2% at EOT and 18.2% at 24 weeks after EOT, while no participants in the PEG-IFN monotherapy group achieved HBsAg clearance at either time point. In Part A2 of the ENHANCE study, 14.6% and 16.7% of participants in this high-baseline subgroup also achieved HBsAg clearance at EOT and 8 weeks after EOT, respectively. These results support further evaluation of BRII-179-based immune activation strategies in patients with higher baseline HBsAg, a population that has historically been more difficult to achieve functional cure in. The treatment regimens in each study were generally safe and well tolerated. Dr. David Margolis, Chief Medical Officer of Brii Biosciences, said: "Our Phase IIb study results provide a more solid scientific basis for continued evaluation of BRII-179-based immune activation and enrichment strategies. At the same time, these results provide important insights into how to use BRII-179 to activate HBV-specific immunity and how to guide subsequent treatment based on early immune responses. Taken together, these findings are expected to help guide the design of future clinical studies, including studies in populations with higher baseline HBsAg levels in whom functional cure is more difficult to achieve."