The Board of Brii Biosciences Limited announced interim findings from a Phase 2 study, which showed that combination therapy with BRII-835 (also known as VIR-2218) and BRII-179 (also known as VBI-2601) was safe and well-tolerated, induced stronger anti-hepatitis B surface antigen antibody responses and led to improved HBsAg-specific T-cell responses, when compared with BRII-835 or BRII-179 alone. All cohorts achieved HBsAg reduction at the end of treatment with a mean decrease of -1.7 to -1.8 log10 IU/mL. In addition, two participants in combination cohorts achieved maximum reductions in HBsAg at or below the lower limit of quantification by Week 40, along with robust HBsAg-specific antibody and T-cell responses.

The Company is developing BRII-835, a small interfering ribonucleic acid, and BRII-179, a recombinant protein-based hepatitis B virus immunotherapeutic, as a combination therapy to provide a functional cure for HBV infection. With complementary mechanisms of action previously demonstrated in Phase 1b studies as single agents, this Phase 2 study of BRII-835 and BRII-179 combination shines an important light on how to restore patients' highly suppressed or exhausted immune responses. Additional data from this trial are expected later this year.

The Phase 2, randomized, open-label trial is ongoing to evaluate the safety and efficacy of BRII-835 and BRII-179 as a combination therapy for the treatment of chronic HBV. Results presented are from 50 participants that were broken up into three cohorts to receive nine subcutaneous doses of 100 mg BRII-835 alone (Cohort A) every four weeks through Week 32 or with the addition of 40 g BRII-179 co-admixed with (Cohort B) or without (Cohort C) 3 MIU IFN- as co-adjuvant from Week 8 through Week 40, all administered via intramuscular injection. Data from the Phase 2 study will be shared in an oral presentation, titled Preliminary Safety and Efficacy of the Combination Therapy of BRII-835 and BRII-179 Treating Chronic HBV Infection, at the 32nd Conference of the Asian Pacific Association for the Study of the Liver (APASL 2023), taking place in Taipei, Taiwan, on February 18, 2023 at 14:10 local time.