Ricin Vaccine Poster Presented at the 2015 ASM Biodefense

Soligenix, Inc. announced today that it presented data from its recent preclinical study that demonstrated the efficacy and safety of its heat-stabilized ricin toxin vaccine (RiVax) in a non-human primate (NHP) lethal aerosolized ricin exposure model.

The data was presented in a poster session at the American Society of Microbiology (ASM) Biodefense and Emerging Diseases Research meeting on Wednesday, February 11, 2015 at Washington Marriott Wardman Park, 2660 Woodley Rd. NW in Washington, DC.

Soligenix has been developing RiVax, its proprietary ricin toxin vaccine, in conjunction with its heat stabilization technology, ThermoVax, as a heat-stable biodefense vaccine. Vaccination with RiVax protected all animals from acute lethal death due to aerosolized ricin exposure, in contrast to unvaccinated animals that died within 40 hours.

In the study, 12 animals were vaccinated with RiVax and 6 animals were given an injection of placebo (unvaccinated control). Each animal received 3 intramuscular injections, administered at time 0, 30 days and 60 days.

Vaccination with RiVax was well tolerated with no evidence of elevated heart rate, respiration or temperature. All RiVax-vaccinated animals generated neutralizing antibodies after the third injection. To fully test the efficacy of the vaccine, all animals were exposed to an aerosol of ricin toxin 3-5 times the amount that is known to result in death of untreated animals.

All RiVax-vaccinated animals survived exposure, while all unvaccinated control animals died within 40 hours, demonstrating a statistically significant (p<0.0001) improvement in survival. Moreover, the lungs of the RiVax-vaccinated animals did not demonstrate any signs of irreversible damage, unlike those of the unvaccinated control animals.

“The improvement in both survival and morbidity with the use of this well-tolerated vaccine is a significant step forward in the development of RiVax for emergency preparedness use”, stated Oreola Donini, PhD, Senior Vice President and Chief Scientific Officer of Soligenix. “Previous studies with RiVax have demonstrated significantly enhanced thermostability indicating that cold chain storage will potentially not be required for this vaccine, enabling it to be stored and distributed at room temperature.”

RiVax is currently the subject of a preclinical and clinical development contract awarded by the National Institute of Allergy and Infectious Diseases (NIAID) and worth up to $24.7 million over 6 years.

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