ANNAPOLIS, Md., June 4, 2014 /PRNewswire/ -- PharmAthene, Inc. (NYSE MKT: PIP) announced today that new data from its SparVax ® anthrax vaccine program were recently presented at the 2014 U.S. Food and Drug Administration (FDA) Medical Countermeasures Initiative (MCMi) Regulatory Science Symposium in Silver Spring, MD.
In a presentation entitled, " Recombinant Protective Antigen Vaccine (SparVax ®) Provides Protection Equivalent to BioThrax ® Against Lethal Challenge with Bacillus anthracis in New Zealand White Rabbits," Dr. Sherry Crowe, Director, Immunology for PharmAthene, presented survival and toxin neutralization assay (TNA) results from a non-clinical anthrax aerosol challenge model.
In this study, three groups of twenty New Zealand White (NZW) rabbits were vaccinated with SparVax ® via intramuscular injection, on study days 0 and 28 at doses of 3, 9, or 27 micrograms. In addition, twenty animals were vaccinated with BioThrax ®, the currently-licensed anthrax vaccine. On the 70 th day of the study, the NZW rabbits were challenged with a lethal dose of aerosolized anthrax spores.
The results of the study demonstrated 100% survival (i.e. equivalent protection) of SparVax ® compared to BioThrax ®. In addition, the preliminary TNA data showed that the antibody titers for SparVax ® in this study were up to 2-fold higher than BioThrax ®, demonstrating that SparVax® is at least equivalent to BioThrax ® as measured by either survival or TNA using the benchmark NZW rabbit model.Eric Richman, President and Chief Executive Officer, remarked, "These latest data provide additional supportive evidence of the potential efficacy of SparVax ® as a novel next-generation recombinant protective antigen (rPA)-based anthrax vaccine. One of the requirements for licensure of rPA vaccines is equivalency relative to the current vaccine, so we are encouraged by these results. We are also especially intrigued by the TNA data, which show elevated antibody titers (up to 2-fold higher) for SparVax ® as compared to BioThrax ®, suggesting the potential for a more potent immune response following vaccination with SparVax ®." In a second poster presentation entitled " Imaging Capillary Electrophoresis Discriminates Slow from Fast Asparagine Deamidation that may Predict Potency for Recombinant Protective Antigen Anthrax Vaccines," Dr. Bradford Powell, Director, Analytical Sciences, presented new analytical data for SparVax ® evaluating the structural characteristics of rPA relative to biological activity. The ongoing expansion of this body of analytical work by Dr. Powell's team will assist PharmAthene in constructing a reliable stability model that will be useful in predicting the potential shelf life of the rPA anthrax vaccine. PharmAthene's rPA anthrax vaccine program has been funded in whole or in part with federal funds from the National Institute of Allergy and Infectious Disease, National Institutes of Health and the Biomedical Advanced Research and Development Authority (BARDA).