BRII-B(02137) published a cross-study analysis of HBsAg rebound after treatment completion at APASL 2026.

BRII-B (02137) announced that at the 35th annual meeting of the Asian Pacific Association for the Study of the Liver (APASL 2026) held in Istanbul, Turkey, from April 22 to 25, the company presented a cross-study summary analysis of the characteristics of hepatitis B surface antigen (HBsAg) rebound after treatment. This analysis evaluated the occurrence of HBsAg rebound after treatment completion (EOT) in participants with chronic hepatitis B virus (HBV) infection who achieved HBsAg clearance with nucleoside reverse transcriptase inhibitors (NRTIs) in two Phase II studies: ENSURE and BRII-179-002. ENSURE was a Phase II study aimed at assessing the safety and effectiveness of combination therapy in improving functional cure in HBV. The first three arms compared the treatment outcomes of elebsiran combined with pegylated interferon-alpha (PEG-IFN) to PEG-IFN monotherapy, while the fourth arm evaluated the potential role of BRII-179 in selecting immunological response-dominant populations and enhancing HBsAg clearance rates. BRII-179-002 was a multicenter, randomized, double-blind Phase II concept validation study aimed at evaluating the combination of BRII-179 with PEG-IFN on top of PEG-IFN therapy. This analysis summarized data from the two studies to assess the incidence, magnitude, and clinical relevance of HBsAg rebound after EOT in participants receiving PEG-IFN monotherapy or combination therapy with elebsiran or BRII-179. The comprehensive analysis showed that participants had good clinical outcomes after discontinuation: the levels of HBsAg rebound were mostly below 100 IU/mL, with the majority rebounding below 10 IU/mL. The HBV DNA rebound rate was low after NRTI discontinuation, with no clinically significant alanine aminotransferase (ALT) elevations related to NRTI cessation observed. Overall, these results suggest that participants achieved sustained immunological control after treatment completion, further supporting the feasibility of safely discontinuing NRTIs in combination therapy regimens based on PEG-IFN. It is worth noting that compared to a 24-week consolidation phase of NRTI, a shorter consolidation period (12-20 weeks) did not increase the incidence of HBsAg rebound, suggesting that shortening or omitting NRTI consolidation therapy may be feasible in future treatment strategies. Dr. David Margolis, Chief Medical Officer of the company, stated, "These accumulating evidence is encouraging, showing that our novel combination therapy approach not only achieves rapid HBsAg clearance but also maintains sustained immunological control after discontinuation. These findings further enhance our confidence in BRII-179 and elebsiran as key components of the next-generation HBV cure strategy. We look forward to obtaining more data from the ongoing studies in 2026."