COLUMBIA, Md.--(BUSINESS WIRE)--

Osiris Therapeutics, Inc. (OSIR), announced today interim one-year results from its groundbreaking clinical trial evaluating Prochymal (remestemcel-L) for the treatment of patients experiencing first-time acute myocardial infarction. The trial is the largest study of allogeneic or "off-the-shelf" stem cells ever conducted in heart attack patients. A total of 220 patients were given a single infusion of either Prochymal or placebo through a standard intravenous line within seven days of an acute heart attack.

Cardiac MRI assessments were conducted for six months following infarct to evaluate cardiac remodeling. Patients receiving Prochymal had significantly less cardiac hypertrophy, as measured by cardiac MRI, compared to patients receiving placebo (p<0.05). Patients treated with Prochymal also experienced significantly less stress-induced ventricular arrhythmia (p<0.05). Cardiac hypertrophy and ventricular arrhythmia are indicators of pathological remodeling following heart injury and provide insight into the mechanism by which mesenchymal stem cells attenuate heart injury following a myocardial infarction.

The mechanistic data is complemented by clinical data showing treatment with Prochymal resulted in a statistically significant reduction in heart failure. In the study, seven patients who were treated with placebo have progressed to heart failure requiring treatment with intravenous diuretics, compared to none of the Prochymal patients (p=0.01). Furthermore, patients receiving placebo tended to require re-hospitalization for cardiac issues sooner than the patients receiving Prochymal (median 27.5 days vs. 85.5 days).

This study is the largest of its kind and provides key insights into the mechanism of action of mesenchymal stem cells in the setting of acute myocardial infarction, said Lode Debrabandere, Ph.D., Senior Vice President of Therapeutics at Osiris. These important mechanistic observations are consistent with data obtained from our preclinical models and from the first placebo-controlled human trial with Prochymal published in the Journal of the American College of Cardiology. Given the quality of the data and highly encouraging results observed thus far, we are extending the trial's duration to capture a better understanding of the long-term clinical benefits of MSCs."

The trial also demonstrated that treatment with Prochymal was safe. There were no infusional toxicities observed in patients receiving Prochymal. Serious adverse events occurred with equal frequency in both treatment groups (31.8%). To date, there have been 5 deaths in the trial, 2 in the Prochymal group and 3 in the placebo group.

For interventional cardiologists, keeping our myocardial infarction patients from progressing to heart failure is central to our mission, said Mark Vesely, M.D., Principal Investigator on the Study and Assistant Professor of Medicine (Interventional Cardiology) at the University of Maryland School of Medicine. It is remarkable and very encouraging to see significant changes in clinically meaningful parameters this early in the study. We look forward to the additional data that will be gathered as the study progresses, which will help us to better understand both the magnitude and durability of the benefit to treatment.

Prochymal, the worlds first and only stem cell drug approved by an internationally recognized regulatory authority, is used for the treatment of graft vs. host disease (GvHD). GvHD is a devastating complication of bone marrow transplantation that kills up to 80 percent of children affected. Prochymal is now approved in Canada and New Zealand, and is currently available in seven other countries including the United States under an Expanded Access Program (EAP).

About the Trial

This Phase 2, multi-center, randomized, double-blind, placebo-controlled study is evaluating the safety and efficacy of Prochymal (ex-vivo cultured adult human mesenchymal stem cells) intravenous infusion following acute myocardial infarction. A total of 220 patients were randomized (1:1) at 33 centers in the United States and Canada and received a single intravenous infusion of Prochymal or placebo within 7 days following first acute myocardial infarction. In addition to screening and baseline visits prior to the infusion, initially follow-up evaluations were scheduled to be conducted through 2 years. Given the encouraging results observed at the one year time-point, the trial is being extended to include 5 years of follow-up. Both male and female subjects between 21 and 85 years of age were enrolled. Patients had to have a left ventricular ejection fraction (LVEF) between 20% and 45% as determined by quantitative echocardiography or cardiac MRI at least 24 hours after successful reperfusion of the culprit vessel. In addition, troponin levels must have been greater than 4 times the upper limit of normal during the first 72 hours of hospitalization for the MI.

Read more from the original source:
Prochymal Significantly Reduces Hypertrophy, Arrhythmia and Progression to Heart Failure in Patients Suffering a Heart ...