Brii Bio Reports Mixed Phase 2b Results for Hepatitis B Therapy

The ENRICH study, which employed BRII-179 as a priming therapy before administering elebsiran and PEG-IFNα, achieved HBsAg loss rates of 42.9% and 40.0% across two dosing schedules. These figures align with earlier clinical data, reinforcing the potential of BRII-179 to trigger essential immune responses. In contrast, the concurrent triple-regimen approach tested in the ENHANCE study failed to outperform previous benchmarks, yielding an HBsAg loss rate of 25.5%. Subgroup analysis further suggested that BRII-179 maintains its efficacy even in patients with higher baseline antigen levels.

Despite these clinical findings, the path forward for the elebsiran program faces significant regulatory and corporate uncertainty. Brii Bio is currently involved in arbitration with Vir Biotechnology regarding manufacturing technology transfer. According to Chief Medical Officer Dr. David Margolis, the company has reached preliminary alignment with Chinese regulators on a registrational study design for the ENRICH protocol. However, the company stated it cannot commit to a Phase 3 trial for any elebsiran-based combination until the legal dispute is resolved. No new safety concerns were identified in either study, and more comprehensive data are expected to be presented at a scientific conference later this year.