Osiris Therapeutics, Inc. announced US Food and Drug Administration (FDA) clearance to broaden its expanded access programme (EAP) for Prochymal, now making the investigational stem cell product available to adults with life-threatening Graft vs. Host Disease (GvHD). In May of 2008, FDA approved the first Prochymal EAP for the treatment of paediatric GvHD patients.

Congress and the FDA created the expanded access programme to facilitate the availability of promising new drugs to desperately ill patients before general marketing begins. The programme allows for investigational drugs to be made available to patients under certain circumstances during evaluation in late stage clinical trials when no satisfactory alternative therapy is available. For expanded access, the FDA must determine that the available scientific evidence, taken as a whole, demonstrates that the drug may be effective and would not expose the patients to unreasonable risks.

Additionally, the FDA permits companies meeting certain criteria to charge for the investigational product. Expanded access to Prochymal was initially restricted to only paediatric patients suffering from steroid refractory GvHD until patient enrolment in the phase III pivotal trial was completed.

Prochymal, a formulation of adult mesenchymal stem cells designed to provide therapeutic benefit by controlling inflammation, promoting tissue regeneration, and preventing scar formation, is in phase III clinical trials for GvHD and Crohn's disease. Enrolment in the phase III pivotal trial for steroid-refractory GvHD was recently completed. Enrolment is ongoing in another phase III trial for acute GvHD and in a phase III trial for Crohn's disease.

"As a transplant physician who has used Prochymal, I have seen first hand the power of this promising therapy to reverse otherwise non-responsive GvHD," said Dr. Hans Klingemann, director, bone marrow and hematopoietic stem cell transplantation programme at Tufts Medical Center. "This is a disease that is so devastating that survival is often measured in days. This action by FDA is significant because it now enables us to provide all of our critically ill GvHD patients with faster and more reliable access to Prochymal."

GvHD is a life-threatening immune reaction that can occur in patients following bone marrow transplantation. Steroids are typically used to control symptoms of the disease, although they are only effective in approximately 35% of patients. Mortality can exceed 85% for patients with GvHD that do not respond to steroids.

Under the EAP, patients two months to 70 years of age, inclusive, who have been diagnosed with GvHD that is unresponsive to steroid therapy, are eligible to receive Prochymal.

In November 2008, Osiris and Genzyme announced a strategic alliance for the development and commercialization of Prochymal. Under the terms of the agreement, Osiris will commercialize Prochymal in the United States and Canada, and Genzyme will commercialize the treatment in all other countries.

Prochymal is a preparation of mesenchymal stem cells specially formulated for intravenous infusion. The stem cells are obtained from the bone marrow of healthy adult donors. Prochymal is currently being evaluated in Phase III trials for steroid refractory GvHD, acute GvHD, and Crohn's disease. Prochymal has been granted Fast Track status by FDA for all three of these indications. Prochymal also obtained Orphan Drug status by FDA and the European Medicines Agency for GvHD. Prochymal is being studied in Phase II trials for the treatment of COPD, type 1 diabetes, and acute myocardial infarction. Additionally, the Department of Defense recently awarded Osiris a contract to develop Prochymal as a treatment for acute radiation syndrome.

Osiris Therapeutics, Inc. is the leading stem cell therapeutic company focused on developing products to treat serious medical conditions in the inflammatory, orthopaedic and cardiovascular areas. The company's pipeline of internally developed biologic drug candidates under evaluation includes Prochymal for inflammatory, autoimmune, and cardiovascular indications, as well as Chondrogen for arthritis in the knee.