SNAPvax™ Potentially Reverses Suppressive Tumor Microenvironment

Vaccitech plc announced yesterday the publication of research in preclinical animal models demonstrating the potential of SNAPvax for use in a novel paradigm for cancer treatment referred to as "VAX-INNATE."

The results show that intravenous administration of SNAPvax not only primes and expands tumor-specific cytotoxic T cells that mediate tumor killing but also reverses suppression in the tumor microenvironment associated with significantly improved tumor regression.

The research evaluated SNAPvax co-delivering tumor antigens and a powerful Toll-like receptor (TLR)-7/8 adjuvant by two different routes (IV or subcutaneous) in tumor-bearing mice.

While SNAPvax primed and expanded a high magnitude of antigen-specific T cells by both routes of administration, SNAPvax administered by the IV route induced systemic Type I interferon that markedly reduced the number of immunosuppressive monocytes and macrophages in the TME leading to improved T cell-mediated tumor regression.

"The research by Baharom and the Seder Lab at NIH offers new insights as to how cancer vaccines can be best leveraged to maximize therapeutic effect," said Andrew Ishizuka, M.D., Ph.D., SVP at Vaccitech, in a press release on October 27, 2022.

"It is broadly recognized that T cells and checkpoint inhibitors that unleash their potential are essential, but this study highlights the critical importance of engaging the innate immune system to reverse suppressor populations in the TME that can otherwise inhibit T cells."

"SNAPvax and our viral platforms, ChAdOx and MVA, are ideal for providing these essential ingredients."

"We look forward to validating SNAPvax's potential alone and combined with ChAdOx in upcoming clinical studies."