Osiris Therapeutics, Inc announced the final two-year results for the company's trial evaluating Prochymal for the treatment of acute myocardial infarction. Prochymal is a proprietary formulation of adult stem cells designed to provide therapeutic benefit by controlling inflammation, promoting tissue regeneration, and preventing scar formation. This double-blind, placebo-controlled study of 53 patients, which evaluated safety and preliminary efficacy, found heart attack patients receiving the intravenous therapy had lower rates of adverse events and significantly improved heart function.

Important findings include -- the trial met its primary endpoint demonstrating safety of Prochymal in the acute MI setting; patients receiving Prochymal had fewer adverse events compared to placebo; a lower percentage of patients treated with Prochymal required repeat hospitalization; patients receiving Prochymal had reduced incidence of cardiac arrhythmia; patients receiving Prochymal had a significant and durable improvement in cardiac function.

"This study adds convincing long-term data to the excellent safety profile of Prochymal, having now treated hundreds of patients in trials over the past decade," said C Randal Mills, president and CEO of Osiris Therapeutics. "We are excited that Prochymal demonstrated strong evidence of efficacy beyond the best cardiac care available at present. We are now advancing this program into a larger phase-II trial, focusing on patients with more severe heart damage."

Recently, Osiris completed enrolment in a phase-III trial of Prochymal for the treatment of steroid-refractory acute graft versus host disease (GvHD). In January, clearance from US Food and Drug Administration (FDA) was received to broaden the expanded access programme for Prochymal, now making the investigational stem cell product available to adults, as well as paediatric patients, with life-threatening GvHD. In 2008, Osiris and Genzyme Corp. 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.

"This placebo controlled study was truly first of its kind and the data produced is promising," said Timothy Henry, director of Research at the Minneapolis Heart Institute Foundation at Abbott Northwestern. "It clearly suggests that allogeneic adult stem cells have significant potential to improve recovery following a heart attack and can prevent long term adverse effects. Given the fact that we can administer this drug through a standard IV in an acute setting, Prochymal could become an integral part of standard of care for treatment of heart attacks everywhere."

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.