VBI Vaccines Inc. announced that the first patient has been dosed in a second Phase 2a/2b clinical study evaluating VBI-2601 (BRII-179), an immunotherapeutic candidate targeting chronic hepatitis B virus (HBV). This newly announced Phase 2 study will assess VBI-2601 as an add-on therapy to the standard-of-care, nucleos(t)ide reverse transcriptase inhibitor (Nrtl) and pegylated interferon (PEG-IFN-a) therapy, which currently has a functional cure rate of approximately 9%. A functional cure for chronic HBV infection is defined as achievement of undetectable HBV surface antigen (HBsAg) levels and sustained suppression of HBV DNA.

The Phase 2a/2b trial of VBI-2601 (BRII-179) is a double-blind, randomized, placebo-controlled, parallel-group study to evaluate the clinical effect of adding VBI-2601 (BRII-179) to existing PEG-IFN-a and Nrtl standard-of-care therapy in non-cirrhotic chronic HBV patients. Patients participating in the study have had partial responses to ongoing PEG-IFN-a and NrtI treatment. Phase 2a: Expected enrollment of 120 patients; Primary endpoint: The percentage of patients with HBsAg loss at completion of treatment.

Phase 2b: Expanded enrollment of 480 patients; and Primary endpoint: The percentage of patients achieving a functional cure, defined as undetectable HBsAg and sustained suppression of HBV DNA.