Soligenix commences enrollment in its Phase 3 Orbec clinical trial for acute GI GVHD

Soligenix, Inc., (Soligenix or the Company) (OTC Bulletin Board: SNGX), formerly known as DOR BioPharma, Inc., a late-stage biotechnology company, announced today that it has initiated enrollment in its confirmatory Phase 3 randomized, double-blind, placebo-controlled, multicenter clinical trial evaluating orBec(®) for the treatment of acute gastrointestinal Graft-versus-Host disease (GI GVHD). The initiation of enrollment in this trial also triggered the payment and receipt by Soligenix of a $1 million milestone pursuant to the Company's collaboration agreement with Sigma-Tau Pharmaceuticals, Inc.

This Phase 3 clinical trial, also referred to as the SUPPORTS protocol (Sparing Unnecessary Prednisone Phase 3 orBec(®) Randomized Treatment Study), will enroll an estimated 166 patients to confirm the clinically meaningful endpoints observed in previous Phase 2 and Phase 3 clinical studies. The primary endpoint is the treatment failure rate at Study Day 80. This endpoint was successfully measured as a secondary endpoint (p-value 0.005) in the Company's previous Phase 3 study as a key measure of durability following a 50-day course of treatment with orBec(®) (i.e., 30 days following cessation of treatment). The SUPPORTS trial will be conducted at major transplant centers throughout the US and is expected to complete with clinical data available in the first half of 2011.

The SUPPORTS trial will be conducted pursuant to a Special Protocol Assessment (SPA) agreement that the Company had reached with the US Food and Drug Administration (FDA). An agreement via the SPA procedure is an agreement with the FDA that a Phase 3 clinical trial's design (e.g., endpoints, sample size, control group and statistical analyses) is acceptable to support a regulatory submission seeking new drug approval. The European Medicines Agency (EMEA) also agreed that should the new confirmatory Phase 3 study produce positive results, the data would be sufficient to support a marketing authorization approval in all 27 European Union (EU) member states.

Keith Sullivan, MD, James B. Wyngaarden Professor of Medicine and Chief of the Division of Medical Oncology and Transplantation at Duke University Medical Center and Co-Principal Investigator of the SUPPORTS study, said, "In over 30 years of clinical studies evaluating potential treatments for acute GI GVHD, only the Phase 2 and 3 studies with orBec(®) have been shown to have a positive impact on both controlling GI GVHD and improving patient survival. By using these data in the design of this Phase 3 clinical study, I am confident that it has the potential to replicate the outcomes previously demonstrated including the primary endpoint. I look forward to working with the Soligenix team and my fellow clinicians in the execution of this clinical study so that transplant teams around the world can include orBec(®) as part of their arsenal to fight this debilitating disease."

"orBec(® )has demonstrated consistent and meaningful clinical benefit to patients in Phase 2 and 3 clinical trials in GI GVHD," stated Brian L. Hamilton, MD, PhD, Senior Vice President and Chief Medical Officer of Soligenix. "The depth and strength of our available Phase 3 data allowed us to design and power this confirmatory trial to maximize orBec(®)'s likelihood of success. The primary endpoint, established via the SPA procedure as the treatment failure rate at Study Day 80, is designed to replicate the statistical significance from our prior Phase 3 clinical trial with orBec(®). We look forward to completing this clinical trial and being the first company to address the unmet medical need of GI GVHD. Launching this important trial is a testimony to the extraordinary talents and efforts of the clinical and regulatory teams at Soligenix, along with the support of our partners, vendors and clinical investigators."