Soligenix, Inc., a late-stage biopharmaceutical company, announced promising preliminary results from a preclinical study of SGX202 (oral beclomathasone dipropionate or BDP) in a canine gastrointestinal acute radiation syndrome (GARS) model. The results indicate that dogs treated with SGX202 demonstrated statistically significant (p=0.04) improvement in survival after exposure to lethal doses of total body irradiation (TBI) when compared to control dogs.

These results demonstrate that SGX202 has the potential to reduce the inflammatory cytokine storm induced by the radiation damaged gastrointestinal (Gl) tract. The GI tract is extremely sensitive to radiation injury. GI damage is the major cause of rapid mortality during high dose radiation exposure, such as could be encountered during nuclear accidents or with the use of dirty bombs. Gut injury from high dose radiation is associated with epithelial cell damage and hypoperfusion of the intestine, which stimulates a vigorous local and systemic inflammatory response.

The aim of the study was to determine whether SGX202 could improve survival and GI recovery after TBI using a well-established GARS dog model. Six dogs were exposed to TBI (12 Gy administered at 70 cGy/min), and then given autologous bone marrow and SGX202 with supportive care; four dogs were used as controls and not treated with SGX202.  Autologous bone marrow was given to reduce the duration and impact of the radiation-induced hematopoietic syndrome and allow for a focus on measures to treat the GI effects of TBI.  SGX202 was administered two hours after TBI and daily until GI recovery (up to day 100 post exposure).  Median survival post exposure in the control group was 8 days, compared to greater than 100 days in the SGX202 treated group.  These results demonstrate that SGX202 has the potential to reduce the local inflammation in the radiation damaged gastrointestinal (Gl) tract.  Analysis of the full dataset from this study remains ongoing and is anticipated to be published in a peer reviewed journal.

The study was supported by a $1 million grant from the National Institutes of Allergy and Infectious Diseases (NIAID), and was conducted by George Georges, MD, Associate Member of the Clinical Research Division at Fred Hutchinson Cancer Research Center.

“These preliminary results suggest that SGX202 may significantly improve survival from GARS,” stated Dr. Georges. “SGX202 may potentially inhibit the cellular and innate immune mechanisms within the gut mucosa that exaggerate mucosal damage, and improve GI recovery after radiation. In the challenging area of radiation injury, the study met its primary objective in protecting dogs from GARS and extending their survival. We are completing our analysis of the data so that we may extend our investigations of SGX202 in GI recovery after radiation exposure and build upon these promising results.”

“The current dog model of GARS used by Dr. Georges appears to be a robust model for studying the supportive care needs after TBI and for evaluating countermeasures for improving survival after TBI,” stated Robert N. Brey, PhD, Chief Scientific Officer of Soligenix. “These results are encouraging and suggest that SGX202 may be an effective post exposure therapy for acute radiation syndrome.  Further, these findings support the active pharmacology of oral BDP and may have positive implications for the ongoing NCI-supported Phase 1/2 clinical study in radiation enteritis. We believe that these promising results merit further investigation and potential government funding of radiation injury in the Defense sector.”

The potential occurrence of industrial and medical radiation accidents and the threat of terrorist events involving radioactive material mandate the development and implementation of effective treatments of radiation injury. The GI tract is highly sensitive to radiation damage. Substantial injury to the GI tract after radiation exposure results in death. In most radiation scenarios, injury to the hematopoietic system and gastrointestinal tract are the main determinants of survival. There is an urgent need to develop specific countermeasures against the lethality caused by intestinal exposure to radiation and against the pathophysiological manifestations of radiation-induced gastrointestinal injury.

Soligenix, Inc. (Soligenix) is a late-stage biopharmaceutical company developing products to treat life-threatening side effects of cancer treatments and serious gastrointestinal diseases, and vaccines for certain bioterrorism agents.