VBI Vaccines Announces Positive Interim Phase 1b/2a Data for Hepatitis B Immunotherapeutic in Patients with Chronic Infection

VBI Vaccines Inc. (Nasdaq: VBIV) (VBI), a commercial-stage biopharmaceutical company developing next-generation infectious disease and immuno-oncology vaccines, today announced positive interim clinical results from the ongoing Phase 1b/2a study of VBI-2601 (BRII-179), a novel recombinant, protein-based immunotherapeutic candidate for the treatment of chronic hepatitis B virus (HBV) infection, in development in collaboration with Brii Biosciences.

“These early data from the low-dose cohorts are very encouraging and provide a human proof-of-concept that leads us to believe VBI-2601 (BRII-179) could be an effective and critical component of a functional cure for chronic hepatitis B patients,” said Jeff Baxter, VBI’s President and CEO. “A functional cure for chronic hepatitis B is likely to require multiple components sufficient to (1) drive down HBV DNA, (2) drive down immunosuppressive HBV surface antigen, and (3) induce or restore HBV-specific long-term immunologic control against HBV infection. This study was designed to assess the ability of VBI-2601 (BRII-179) to induce or restore antibody and T cell responses against HBV. Responses seen to-date occur rarely in the natural history of this chronically-infected population. We are exploring various combinations of VBI-2601 (BRII-179) with other therapeutic modalities for the next phase of development to achieve functional cure.”

The low-dose cohorts of the ongoing two-part Phase 1b/2a evaluated VBI-2601 (BRII-179), unadjuvanted and adjuvanted, in combination with a nucleos(t)ide analogue (NUC) therapy, intended to reduce HBV DNA, vs. NUC therapy only, in chronically-infected HBV patients. Objectives of this early-stage study were to elicit immunologic responses known to be associated with functional immunity against HBV infection, including the stimulation of T cell immunity and the induction of antibody responses to HBV surface antigens (S, Pre-S1, Pre-S2). The interim data showed:

• Potent re-stimulation of T cell responses to HBV surface antigens seen in 67% (n=6/9) and 78% (n=7/9) of evaluable patients in the low-dose VBI-2601 unadjuvanted and adjuvanted study arms, respectively
• Antibody responses against HBV surface antigens were observed in 60% of evaluable patients (n=6/10) in the unadjuvanted cohort and in 67% (n=6/9) in the adjuvanted cohort
• The low-dose, with and without the adjuvant, was well-tolerated with no safety signals observed

“Recent advances in the development of therapeutics for HBV infection have shown that strong reductions of both HBV DNA and circulating S-antigen are possible, however, restoration of HBV-specific antibody and T cell responses have historically been a challenge, underscoring the importance of a combination with an immunotherapeutic,” said David E. Anderson, Ph.D., VBI’s Chief Scientific Officer. “The levels of immune responses that we were able to elicit with the low dose of VBI-2601 (BRII-179) are an important achievement and we are working hard to be able to provide a solution for patients with such a complex and highly infectious virus.”