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Heat-stable Ebola Vaccine

18 July 2016

Soligenix, Inc. (OTCQB: SNGX), a late-stage biopharmaceutical company focused on developing and commercializing products to treat rare diseases where there is an unmet medical need, announced today positive preliminary proof-of-concept results from its collaboration with Axel Lehrer, Ph.D., an Assistant Professor in the Department of Tropical Medicine, Medical Microbiology and Pharmacology, of the John A. Burns School of Medicine, University of Hawaii at Manoa and Hawaii Biotech, Inc., to develop a heat-stable subunit Ebola virus vaccine. Thermostabilization formulation studies, conducted with Theodore Randolph, Ph.D., at the University of Colorado Boulder, have identified a formulation that enhances the physical stability of the protein and may be dose sparing (i.e., allowing immunization to potentially be achieved with fewer vaccinations).

Dr. Lehrer, a co-inventor of the Ebola vaccine, has shown proof of concept efficacy with subunit Ebola vaccines in non-human primates. Soligenix evaluated its proprietary vaccine thermostabilization technology, ThermoVax, licensed from the University of Colorado, to stabilize components of the vaccine. These studies identified a formulation that maintained the physical state of the Ebola subunit protein despite incubation at 40 degrees Celsius (104 degrees Fahrenheit) for 12 weeks. Moreover, initial testing revealed that two doses of this new formulation is as effective as three doses of a non-stabilized vaccine in generating antibodies to Ebola, even after storage at 40 degrees Celsius for 12 weeks. Further studies evaluating the protective ability of the vaccines are planned. Ultimately, the objective is to produce a thermostable Ebola vaccine for worldwide distribution that does not require cold storage. In preclinical studies, ThermoVax has been previously demonstrated to enhance thermostability of ricin (RiVax), anthrax and human papillomavirus subunit vaccines.

The most advanced Ebola vaccines involve the use of vesicular stomatitis virus and adenovirus vectors, live, viral vectors which complicate the manufacturing, stability and storage requirements. Dr. Lehrer’s vaccine is based on highly purified recombinant protein antigens, circumventing many of these manufacturing difficulties. Application of ThermoVax may allow for a product that can avoid the need for cold-chain distribution and storage, yielding a vaccine ideal for use in both the developed and developing world. “None of the other Ebola vaccines under development have the ability to withstand high temperatures, which is an ongoing concern in areas of the world where filoviruses are endemic”, stated Dr. Lehrer. “The ability to stabilize our vaccine candidate to retain immunogenicity may not only have an impact on logistics, but also has the potential to reach more persons in need with fewer vaccine doses. This would be a tremendous advantage, especially in endemic areas, increasing the number of people receiving sufficient doses of the vaccine to protect them from disease.”