Positive interim results observed in ongoing study of HBV vaccine

VBI Vaccines Inc. announced positive interim clinical results from an ongoing phase 1b/2a study of VBI-2601 (BRII-179), a novel recombinant, protein-based immunotherapeutic candidate for the treatment of chronic hepatitis B infection.

According to a press release, VBI Vaccines collaborated 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,” Jeff Baxter, VBI’s president and CEO, said in the release. “A functional cure for chronic hepatitis B is likely to require multiple components sufficient to (1) drive down hepatitis B virus (HBV) DNA, (2) drive down immunosuppressive HBV surface and other antigens, 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.”

Interim data showed potent restimulation of T cell responses to HBV surface antigens in 67% of patients in low dose cohorts that included unadjuvanted and adjuvanted. Researchers saw antibody responses against HBV surface antigens in 60% of patients in the unadjuvanted group and 67% in the adjuvanted group. The low dose of VBI-2601 with and without the adjuvant was well-tolerated, according to the release. Further, they did not see any safety signals.

Investigators designed the phase 1b/2a study as a two part dose-escalation study evaluating low dose and a high dose of VBI-2601 (BRII-179), with and without an undisclosed adjuvant.

They expect to enroll up to 65 patients, according to the release.

“Recent advances in the development of therapeutics for chronic HBV infection have shown that strong reduction of both HBV DNA and circulating S-antigen is 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,” David E. Anderson, PhD, VBI’s chief scientific officer, said. “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.”