FDA Grants Soligenix Orphan Drug Designation for SGX94 for Treatment of Acute Radiation Syndrome

Princeton, NJ – September 16, 2013 – Soligenix, Inc. (OTCQB: SNGX) (Soligenix or the Company), a clinical stage biopharmaceutical company focused on developing products to treat inflammatory diseases and biodefense countermeasures where there remains an unmet medical need, announced today that the Office of Orphan Products Development of the US Food and Drug Administration (FDA) has granted orphan drug designation to the active ingredient SGX94 for the treatment of acute radiation syndrome (ARS).  SGX94 is an innate defense regulator (IDR), a new class of short, synthetic peptides that accelerates resolution of tissue damage following exposure to a variety of agents including bacterial pathogens, trauma, radiation and/or chemotherapy.

The US Orphan Drug Act is intended to assist and encourage companies to develop safe and effective therapies for the treatment of rare diseases and disorders.  In addition to providing a seven year term of market exclusivity upon final FDA approval, orphan drug designation also positions Soligenix to be able to leverage a wide range of financial and regulatory benefits, including government grants for conducting clinical trials, waiver of expensive FDA user fees for the potential submission of a New Drug Application, and certain tax credits.

“The FDA’s decision to grant SGX94 orphan drug designation signifies an important step for Soligenix as we continue to expand our biodefense pipeline and the many potential applications of our novel IDR technology,” stated Christopher J. Schaber, PhD, President & Chief Executive Officer of Soligenix.  “SGX94’s activity in preclinical models has demonstrated the potential to mitigate damage to the skin and gastrointestinal tract, as well as enabling clearance of infection as a result of damage to the hematopoietic system, all of which occur with varying severity in ARS.  The marketing exclusivity that orphan drug designation imparts adds significantly to the existing patent estate surrounding SGX94.”

About ARS

ARS occurs after toxic radiation exposure and involves several organ systems, notably the skin, the bone marrow and the gastrointestinal (GI) tract.   In the event of a nuclear disaster or terrorist detonation of a nuclear bomb, casualties exposed to >2 Gy are at high risk for development of clinically significant ARS. The chance of survival for people with ARS decreases with increasing radiation dose, with doses of 10-12 Gy causing death within 15 days and lower doses potentially causing death within a few months. The cause of death within 15 days of radiation exposure is usually damage to the GI tract whereas after 15 days death usually is a consequence of bone marrow (hematopoietic) injury. Symptoms of cutaneous (skin) radiation injury are recurring phenomena after ARS.  For the survivors, the recovery process may last from several weeks up to two years. Although the hematopoietic syndrome may be rescued by bone marrow transplantation or growth factor administration, the risk of death due to infection remains very high.  There is currently no established treatment or preventive measure for the GI damage that occurs after high-dose radiation.

About SGX94

SGX94 is an IDR, a new class of short, synthetic peptides that has a novel mechanism of action in that it has simultaneous anti-inflammatory and anti-infective activity.  IDRs have no direct antibiotic activity but modulate host responses, increasing survival after infections with a broad range of bacterial Gram-negative and Gram-positive pathogens, as well as accelerating resolution of tissue damage following exposure to a variety of agents including bacterial pathogens, trauma and chemo- and/or radiation-therapy.  SGX94 has demonstrated safety in a Phase 1 clinical study in healthy human volunteers and efficacy in numerous animal disease models including mucositis, colitis, skin infection and other bacterial infections.  SGX94 was developed pursuant to discoveries made by Professors B. Brett Finlay, PhD and Robert Hancock, PhD of the University of British Columbia, Canada and approximately $40 million has been put towards its development to date, inclusive of government grants.  SGX94, the active ingredient in SGX942, is also in clinical development for the treatment of oral mucositis.

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 NIAID.  Recently, Soligenix announced a worldwide exclusive collaboration with Intrexon Corporation that will focus on the joint development of a treatment for Melioidosis, a high priority biothreat and an area of unmet medical need.

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, including but not limited to, potential market sizes, patient populations and clinical trial enrollment.  Statements that are not historical facts, such as “anticipates,” “estimates,” “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, achieve regulatory approval for or commercialize products based on its technologies, particularly in light of the significant uncertainty inherent in developing vaccines against bioterror threats conducting preclinical and clinical trials of vaccines, obtaining regulatory approvals and manufacturing vaccines, 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 funding to support product development and commercialization efforts, including 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, that it will be able to compete with larger and better financed competitors in the biotechnology industry, that changes in health care practice, third party reimbursement limitations and Federal and/or state health care reform initiatives will not negatively affect its business, 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.