Immunovaccine Inc. (Immunovaccine), a clinical stage vaccine and immunotherapy company,  announced positive results from anthrax challenge studies in non-human primates (monkeys) using an anthrax vaccine formulated with Immunovaccine’s DepoVax delivery system. The studies, performed by the National Institute of Allergy and Infectious Diseases (NIAID) of the National Institutes of Health (NIH), showed that subjects given a single dose of the DepoVax-based vaccine were protected against a lethal anthrax challenge.

The DepoVax formulated anthrax vaccine was tested as a single dose in monkeys to determine how quickly neutralizing antibodies can be produced by the vaccine and to test its ability to protect against a lethal dose of the anthrax causing bacterial spores (B. anthracis).  A group of six animals vaccinated with a single dose of the vaccine was protected from anthrax infection.  Four of the five animals in the study’s positive control group receiving BioThrax were protected as well; however, they were given two doses of the control vaccine.

BioThrax is the only FDA-licensed vaccine however multiple immunizations are needed to provide the necessary protection against exposure to anthrax. Three doses of intramuscular injections of BioThrax are indicated at 0, 1, and 6 months, followed by booster injections at 12 and 18 months. There is currently no licensed anthrax vaccine that can provide protection with one dose.  

In all animals immunized with the DepoVax-based vaccine, antibody titers generally peaked in the first 28 days then persisted until at least day 70, when animals were exposed to the disease agent. In contrast, animals in the control group receiving BioThrax required a second dose to produce protective neutralizing titers.

Further studies will be conducted to evaluate the potential of DepoVax-based vaccines as single dose, rapid protection against anthrax.

“We previously announced data that demonstrated single dose protection in rabbits and the potential for single dose protection in non-human primates.  Now we report for the first time the protective capability of a single dose of a DepoVax-based anthrax vaccine in non-human primates. The results produced in two animal models demonstrate the consistent performance of DepoVax in producing protective immunity with a single dose which may translate to other infectious disease applications including Ebola,” said Dr. Marc Mansour, chief executive officer of Immunovaccine.

These studies are intended to evaluate Immunovaccine’s DepoVax adjuvanting technology and advance the development of next generation bio-defense vaccines. The studies were conducted under NIAID’s preclinical services program vaccine testing contract (HHSN272201200003I/  HHSN27200004),

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 potential for single-dose effectiveness.  The DepoVax platform is flexible and can be used with a broad range of target antigens for preventative or therapeutic applications. The technology is designed to be commercially scalable, with the potential for years of shelf life stability.

Immunovaccine Inc. develops cancer immunotherapies and infectious disease vaccines based on the company’s DepoVax platform, a patented formulation that provides controlled and prolonged exposure of antigens and adjuvant to the immune system.