Immunovaccine Inc., a clinical stage vaccine company, has reported positive results from an immunogenicity study that evaluated anthrax vaccines formulated in the company’s DepoVax platform. This study is part of an ongoing bio-defense research programme which was initiated in February 2012 to utilize Immunovaccine’s DepoVax adjuvanting technology in advancing the development of next generation vaccines against the most threatening biological agents.  Study findings suggested that the DepoVax-based vaccines provided a more rapid and long lasting immune response as compared to the licensed anthrax vaccine BioThrax.

The study, which was conducted under the National Institute of Allergy and Infectious Diseases’ (NIAID) Preclinical Services Programme, was designed to test multiple DepoVax-formulated anthrax vaccines in non human primates, specifically examining immunogenicity and safety after either one or two doses of the vaccine.  Study investigators compared the DepoVax-based vaccines to BioThrax, the only commercially available anthrax vaccine.  BioThrax requires at least two doses to produce immune responses in animal models.

 Preliminary study findings include:

A single dose of DepoVax-formulated anthrax vaccine produced sustained TNA (toxin-neutralizing antibody) titers detected in six of ten animals starting between day 21 and 49. Animals receiving one dose of Biothrax had no detectable TNA titers;

When a second dose of the DepoVax-formulated vaccine was delivered, there was a significant increase in anthrax TNAs in all immunized animals within one week of the booster administration.

Vaccination with the DepoVax-formulated vaccines resulted in no visible injection site reactions.  Detailed microscopic examination showed robust immune cell infiltration to the site of vaccination. There was no evidence of systemic or local safety issues.

“Particularly impressive about these findings is the demonstration that DepoVax-formulated vaccines generate toxin neutralizing antibodies with one dose,” said Dr Marc Mansour, chief science officer of Immunovaccine. “These findings suggest the potential for DepoVax to enable the development of an effective and safe next generation anthrax vaccine.”

More studies with NIAID preclinical services are planned to begin in early 2013. These will examine the ability of neutralizing antibody responses induced by a DepoVax-based vaccine to protect animals from challenge with anthrax.

The positive results from this immunogenicity study are consistent with previous research conducted by Immunovaccine that demonstrated a DepoVax-based vaccine was able to raise higher antibody levels, as compared to two doses of alum-adjuvanted control vaccines. The persisting high antibody levels were induced within four weeks following a single dose of anthrax antigen formulated within DepoVax.

DepoVax is a patented formulation that provides controlled and prolonged exposure of antigens plus adjuvant to the immune system, resulting in a strong, specific and sustained immune response with the capability for single-dose effectiveness.  The DepoVax platform possesses impressive flexibility, allowing it to work with a broad range of target antigens in various therapeutic applications.  The technology is also commercially scalable, with potential for years of stability and ease of use in the clinic.

Immunovaccine Inc. applies its novel adjuvanting platform to the development of vaccines for cancer therapy, infectious diseases and animal health.