Osiris Cleared by FDA to Begin Phase II Stem Cell Trial for the Treatment of Crohn's Disease.

BALTIMORE -- Osiris Therapeutics, Inc. announced today that it has received clearance from the U.S. Food and Drug Administration (FDA) to begin enrollment in a Phase II clinical trial to evaluate the safety and effectiveness of PROCHYMAL(TM) for the treatment of Crohn's Disease. With the launch of this program, Osiris now has five active clinical trials evaluating its proprietary stem cell drugs in autoimmune, oncology, cardiac and orthopedic indications.

PROCHYMAL is an intravenous formulation of mesenchymal stem cells that is currently being evaluated for safety and effectiveness in human clinical trials. These stem cells are obtained from the bone marrow of volunteer donors between 18-32 years of age. Earlier in the year, PROCHYMAL became the first stem cell drug to be granted FDA's Fast Track status for the treatment of the gastrointestinal form of acute graft vs. host disease.

In the United States, over 500,000 people are living with Crohn's Disease. Crohn's can affect any portion of the gastrointestinal tract and is characterized by severe abdominal pain and persistent, frequently bloody diarrhea. The exact cause of Crohn's is unknown, but it is thought to result from a combination of environmental and immune events and leads to chronic, destructive inflammation of the intestine. Crohn's is incurable and up to 70% of patients will require major surgery of their intestine. Even after surgery, symptoms frequently return.

In this trial, PROCHYMAL is being evaluated for its ability to reduce inflammation and repair damaged tissue. Studies have shown that the type of stem cell used in PROCHYMAL, the mesenchymal stem cell or MSC, can specifically target areas of inflammation. Since the cells have the ability to down-regulate the inflammatory process and regenerate tissue, PROCHYMAL may provide a treatment alternative for Crohn's patients who fail conventional therapy, sparing them from the permanently disabling surgery.

"There is a genuine need for a more effective treatment for patients with severe Crohn's Disease", said Jane Onken, M.D., M.H.S., Assistant Professor of Medicine and Director of the Inflammatory Bowel Disease Clinic at Duke University. "The goal is to have targeted anti-inflammatory activity while promoting the repair of damaged tissue. If these stem cells are able to provide that combination, the impact on this and other diseases would be tremendous."

Osiris received clearance to proceed into the Phase II trial after submitting an Investigational New Drug application to FDA for the treatment of inflammatory bowel diseases, including Crohn's. Specifically, the trial will investigate the response of moderate to severe Crohn's Disease in patients that do not respond to steroids and other forms of immune system suppression.

"There is still a significant amount of work to be done to prove the drug is safe and effective," said C. Randal Mills, Ph.D., President and Chief Executive Officer of Osiris. "The initial data is encouraging and gives us confidence to execute our plan to expand the indications for PROCHYMAL. Based upon our understanding of the drug, Crohn's Disease was the obvious next step."

In addition to the Crohn's Disease clinical trial, Osiris is currently enrolling patients in four other stem cell studies. The company has two ongoing Phase II clinical trials with PROCHYMAL to treat graft versus host disease, a life threatening disease affecting patients who have received bone marrow transplants. Osiris has an ongoing Phase I/II clinical trial with CHONDROGEN(TM) for the regeneration of cartilage tissue in the knee. Osiris is also conducting a Phase I clinical trial with PROVACEL(TM) to repair damaged heart tissue in patients who have had heart attacks.

Osiris Therapeutics, Inc. is the leader in adult stem cell therapy. The stem cells produced by Osiris are obtained from adult volunteer donors, avoiding the technical problems and controversy surrounding other stem cell technologies. Using proprietary methods, these cells are grown in culture to very high numbers, allowing a single donor's cells to treat thousands of patients. These cells can be used in patients unrelated to the donor, without rejection, eliminating the need for donor matching and recipient immune suppression. Once transplanted, the cells promote healing of damaged or diseased tissues.