Soligenix, a development stage biopharmaceutical company, has announced that the Office of Orphan Products Development of the US FDA has granted orphan drug designation to OrbeShield (oral beclomethasone 17,21-dipropionate or oral BDP) for the prevention of death following a potentially lethal dose of total body irradiation during or after a radiation disaster.

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 for oral BDP 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 for oral BDP, and certain tax credits.

Oral BDP is a highly potent, topically active corticosteroid that has a local effect on inflamed tissue. BDP is the active ingredient in OrbeShield, currently being developed for the treatment of gastrointestinal acute radiation syndrome (GI ARS), the driving component in early mortality following high doses of total body irradiation (TBI).

“The FDA’s decision to grant oral BDP orphan drug designation signifies an important step for Soligenix as we continue to expand our oral BDP pipeline,” stated Christopher J. Schaber, President & CEO of Soligenix.  “The marketing exclusivity that orphan drug designation imparts adds significantly to the existing patent estate surrounding OrbeShield. We believe that OrbeShield has the potential to be a significant advancement in the preparation necessary for this nation to manage a public health emergency like a nuclear attack.”

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 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.

OrbeShield is formulated for oral administration in GI ARS patients as a single product consisting of two tablets; one tablet  releases BDP in the proximal portions of the GI tract and the other tablet releases BDP in the distal portions of the GI tract.  BDP has been marketed in the US 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.