Soligenix Announces Presentation of OrbeShieldTM Data at Annual Radiation Research Society Meeting

Princeton, NJ – September 28, 2012 – Soligenix, Inc. (OTCQB: SNGX) (Soligenix or the Company), a development stage biopharmaceutical company, announced today that results of a study in a canine model of OrbeShield™ (oral beclomethasone 17,21-dipropionate) will be presented at a poster session entitled, “Post-exposure oral 17,21-beclomethasone dipropionate (BDP) improves survival in a canine gastrointestinal acute radiation syndrome (GI ARS) model.” The presentation will be made during the 58th Annual Meeting of the Radiation Research Society to be held in San Juan, Puerto Rico on September 30 through October 3, 2012.

In the recently completed study in canines and as previously announced, statistically significant survival was observed in dogs that received OrbeShield™ therapy starting both 2 and 24 hours following exposure to total body irradiation (TBI). The program was designed to simulate real world scenarios in which people exposed to various levels of radiation would not be able to reach care centers immediately after a nuclear event. In the study, untreated dogs died at a median time of 8 days when exposed to high dose radiation of 10-12 Gray (Gy) even if the dogs were given intensive supportive care such as antibiotics, intravenous fluids and anti-emetics. Transplant of autologous bone marrow cells also had no effect on the rate of death of the exposed animals due to acute effects on the GI tract. During the observation period, the survival of dogs was strongly correlated to the recovery from acute radiation damage to the GI tract. These studies were conducted by George E. Georges, MD, at the Fred Hutchinson Cancer Research Center (FHCRC) under a National Institute of Allergy and Infectious Diseases (NIAID) funded grant. The OrbeShield™ program is also the subject of a new $600,000 NIAID Small Business Innovation Research (SBIR) grant supporting further evaluation as a treatment for GI ARS.

For more details on the congress, please visit the official congress web site: http://timssnet2.allenpress.com/ECOMradressnet/common/tnt_frontpage.cfm

About GI ARS

ARS occurs after toxic radiation exposure and involves several organ systems, notably the bone marrow the GI tract and later the lungs.   In the event of a nuclear disaster or terrorist detonation of a nuclear bomb, casualties exposed to >2 Gray (Gy) are at high risk for development of clinically significant ARS. Exposure to high doses of radiation exceeding 10-12 Gy causes acute GI injury which can result in death in 5-15 days.  The GI tract is highly sensitive due to the requirement for incessant proliferation of crypt stem cells and production of mucosal epithelium. The extent of injury to the bone marrow and the GI tract are the principal determinants of survival after exposure to TBI.  Although the hematopoietic syndrome can be rescued by bone marrow transplantation or growth factor administration, there is no established treatment or preventive measure for the GI damage that occurs after high-dose radiation. Therefore, there is an urgent need to develop specific medical countermeasures against the lethal pathophysiological manifestations of radiation-induced GI injury.

About OrbeShield™

OrbeShield™ contains BDP, a highly potent, topically active corticosteroid that has a local effect on inflamed tissue. OrbeShield™ is formulated for oral administration in GI-ARS patients as a single product consisting of two tablets; one tablet is intended to release BDP in the proximal portions of the GI tract and the other tablet is intended to release BDP in the distal portions of the GI tract.  BDP has been marketed in the United States and worldwide since the early 1970s as the active pharmaceutical ingredient in inhalation products for the treatment of patients with allergic rhinitis and asthma. Oral BDP may also have application in treating other GI disorders characterized by severe inflammation such as Crohn’s disease and radiation enteritis.

About Soligenix, Inc.

Soligenix is a development stage biopharmaceutical company developing products to treat life-threatening side effects of cancer treatments and serious gastrointestinal diseases, and vaccines for certain bioterrorism agents. Soligenix’s lead product, orBec® (oral beclomethasone dipropionate), is a potent, locally acting corticosteroid that has been initially developed for the treatment of gastrointestinal Graft-versus-Host disease (GI GVHD), a common and potentially life-threatening complication of hematopoietic cell transplantation. Soligenix is also developing proprietary formulations of oral BDP for the prevention/treatment of gastrointestinal disorders characterized by severe inflammation, including pediatric Crohn’s disease (SGX203) and acute radiation enteritis (SGX201), which is the subject of a recently completed National Cancer Institute (NCI)-supported Phase 1/2 clinical trial.

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,” 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.