Soligenix Announces Significant Progress with ThermoVax™ Towards the Development of Heat Stable Vaccines

Princeton, NJ – March 19, 2013 – Soligenix, Inc. (OTCQB: SNGX) (Soligenix or the Company), a clinical stage biopharmaceutical company, announced today key progress in the development of ThermoVax™, its proprietary vaccine thermostabilization technology.  Several complementary preclinical studies have indicated the potential for high temperature stability for a minimum of six months and increased potency of subunit vaccines formulated with ThermoVax™.  These studies have been conducted with the Company’s proprietary ricin toxin vaccine (RiVax™) and anthrax vaccine (VeloThrax™) as part of a continuing program to evaluate the effectiveness of protein subunit vaccines to withstand extremes of temperature and other environmental stress conditions.  The research and development of ThermoVax™ is being supported by a $9.4 million National Institute of Allergy and Infectious Disease (NIAID) grant to Soligenix for biodefense vaccines to prevent ricin toxin and anthrax exposure.

ThermoVax™ is a technology that is designed to eliminate the standard cold chain production, distribution and storage logistics required for most vaccines.  By employing ThermoVax™ during final formulation of RiVax™ and VeloThrax™, results have shown that it is possible to produce stable and potent vaccines that are capable of withstanding temperatures at least as high as 40 degrees Celsius (104 degrees Fahrenheit) for a minimum of six months.  Recent results also indicate that VeloThrax™ formulated with ThermoVax™ and subsequently exposed to temperatures as high as 70 degrees Celsius (158 degrees Fahrenheit) for at least one month, retained full potency in animals as well as other characteristics, such as receptor binding, indicative of full structural integrity. The combination of ThermoVax™ and VeloThrax™ along with a potent secondary adjuvant resulted in rapid onset of antibodies correlated to protection against anthrax in animal models.  These results corroborate earlier findings demonstrated with ThermoVax™ formulated RiVax™ and further demonstrate proof of principle.

Cold chain requirements add considerable cost to the production and storage of current conventional vaccines. According to the Biopharma Cold Chain Sourcebook of 2010, 98% of all vaccines (with a value of $20.6 billion) require shipment through cold chain. Elimination of the cold chain would also enhance the utility of these vaccines for emerging markets and for other applications requiring but lacking reliable cold chain capabilities. Further, the World Health Organization reports that 50% of all global vaccine doses are wasted because vaccines are not kept within required temperature ranges.  NIAID has also highlighted the priority of technologies for biodefense vaccines that focus on broad spectrum approaches including vaccine adjuvants and temperature stabilization for long shelf life, rapid onset of immunity, and surge capacity for production.  For vaccines that are intended for long-term stockpiling, such as for use in biodefense or in pandemic situations, the utilization of ThermoVax™ has the potential to facilitate easier storage and distribution of strategic national stockpile vaccines in emergency situations.

“We are pleased with the progress demonstrated thus far with our vaccines that employ ThermoVax™,” stated Christopher J. Schaber, PhD, President and Chief Executive Officer of Soligenix.  “The ability to engineer vaccines that are able to withstand extreme temperatures and thereby eliminate the cold chain while simultaneously reducing the frequency of vaccinations has the potential to be a significant step forward in vaccine technology. Beyond its biodefense applications, ThermoVax™ has the potential to lead to major cost savings in the production, distribution and storage of currently marketed vaccines and could further facilitate their use in the developing world.  We are excited about the potential utility of the ThermoVax™ technology and recently have initiated discussions with a number of vaccine companies and non-profit organizations regarding the potential for collaboration on heat stable versions of their vaccine candidates.”

About ThermoVax™

ThermoVax™ is a technology that is designed to eliminate the standard cold chain production, distribution and storage logistics required for most vaccines.  The technology utilizes precise lyophilization of protein immunogens with conventional aluminum adjuvants in combination with secondary adjuvants for rapid onset of protective immunity where protective immunity is desired with the fewest number of vaccinations.  RiVax™ and VeloThrax™ are extremely labile in their liquid form requiring careful management under refrigerated conditions at 4 degrees Celsius (39 degrees Fahrenheit).  By employing ThermoVax™ during their final formulation, it is possible to produce stable and potent vaccines that are capable of withstanding temperatures at least as high as 40 degrees Celsius (104 degrees Fahrenheit) for up to six months, with evidence of protein stability at temperatures at least as high as 55 degrees Celsius (131 degrees Fahrenheit) for at least several weeks.

The underlying technology has been developed by Drs. John Carpenter and Theodore Randolph at the University of Colorado.  The vaccine technology is being developed in collaboration with Nanotherapeutics, Inc., SRI International, the University of Kansas, the Wadsworth Center of the New York State Department of Health, and the Tulane National Primate Research Center under the aegis of the cooperative grant form NIAID.

About Soligenix, Inc.

Soligenix is a clinical stage biopharmaceutical company developing products to treat serious inflammatory diseases where there remains an unmet medical need, as well as developing several biodefense vaccines and therapeutics. Soligenix is developing proprietary formulations of oral BDP (beclomethasone 17,21-dipropionate) for the prevention/treatment of gastrointestinal disorders characterized by severe inflammation, including pediatric Crohn’s disease (SGX203), acute radiation enteritis (SGX201) and chronic Graft-versus-Host disease (orBec®), as well as developing its novel innate defense regulator (IDR) technology SGX942 for the treatment of oral Mucositis.

Through its BioDefense Division, Soligenix is developing countermeasures pursuant to the Biomedical Advanced Research and Development Authority (BARDA) Strategic Plan of 2011-2016 for inclusion in the US government’s Strategic National Stockpile. Soligenix’s lead biodefense products in development are a recombinant subunit vaccine called RiVax™, which is designed to protect against the lethal effects of exposure to ricin toxin and VeloThrax™, a vaccine against anthrax exposure. RiVax™ has been shown to be well tolerated and immunogenic in two Phase 1 clinical trials in healthy volunteers. Both RiVax™ and VeloThrax™ are currently the subject of a $9.4 million National Institute of Allergy and Infectious Diseases (NIAID) grant supporting development of Soligenix’s new vaccine heat stabilization technology known as ThermoVax™. Soligenix is also developing OrbeShield™ for the treatment of gastrointestinal acute radiation syndrome (GI ARS) under a $600,000 NIAID Small Business Innovation Research (SBIR) grant. OrbeShield™ has previously demonstrated statistically significant preclinical survival results in two separate canine GI ARS studies funded by the NIH.

For further information regarding Soligenix, Inc., please visit the Company’s Website at www.soligenix.com.

This press release contains forward-looking statements that reflect Soligenix, Inc.’s current expectations about its future results, performance, prospects and opportunities. Statements that are not historical facts, such as “anticipates,” “believes,” “intends,” “potential,” or similar expressions, are forward-looking statements. These statements are subject to a number of risks, uncertainties and other factors that could cause actual events or results in future periods to differ materially from what is expressed in, or implied by, these statements. Soligenix cannot assure you that it will be able to successfully develop or commercialize products based on its technology, particularly in light of the significant uncertainty inherent in developing vaccines against bioterror threats, manufacturing and conducting preclinical and clinical trials of vaccines, and obtaining regulatory approvals, that product development and commercialization efforts will not be reduced or discontinued due to difficulties or delays in clinical trials or due to lack of progress or positive results from research and development efforts, that it will be able to successfully obtain any further grants and awards, maintain its existing grants which are subject to performance, enter into any biodefense procurement contracts with the US Government or other countries, or that the US Congress may not pass any legislation that would provide additional funding for the Project BioShield program. These and other risk factors are described from time to time in filings with the Securities and Exchange Commission, including, but not limited to, Soligenix’s reports on Forms 10-Q and 10-K. Unless required by law, Soligenix assumes no obligation to update or revise any forward-looking statements as a result of new information or future events.