Osiris Therapeutics, Inc announced six-month interim data from a phase-II clinical trial evaluating Prochymal, the company's proprietary formulation of adult mesenchymal stem cells, for the treatment of chronic obstructive pulmonary disease (COPD). Sixty-two patients were enrolled and are being followed for two years in the placebo-controlled study. At the six-month time-point, the data revealed several important findings.

The trial met its primary goal of demonstrating the safety of Prochymal in patients with compromised pulmonary function at the six-month evaluation point. Prochymal significantly decreased systemic inflammation in patients when compared to those receiving placebo, as determined by C-reactive protein (CRP). Despite the reduction in inflammation, pulmonary function in patients receiving Prochymal was not significantly improved compared to those receiving placebo.

"We are very pleased with the interim outcome of this study and that the data continues to support the strong safety profile of this therapy, particularly given the severity of these patients' pulmonary disease," said C Randal Mills, president and CEO of Osiris Therapeutics. "Importantly, we are gratified to obtain clear, objective data that helps bolster our understanding of the anti-inflammatory effects of these remarkable cells. Short-term, these anti-inflammatory effects did not appear to improve pulmonary function in patients with advanced destructive changes of the lung. Collectively however, these findings add to our confidence about the safety and effectiveness of the drug."

Prochymal was evaluated in a total of 62 patients, 58 per cent of them male. The patients ranged in age from 47 to 80 years and suffered from moderate (n=23) to severe (n=39) COPD. Patients had been suffering with COPD for an average of 7.8 years. Patients with asthma were excluded from the trial. All patients in the trial completed the planned course of four infusions without any evidence of infusional toxicity. Oxygen saturation levels were measured throughout each infusion and showed no adverse effects of the infusion. Adverse event rates were comparable for patients receiving Prochymal and placebo. There were no signs of adverse immune reaction after any of the four infusions and no differences in the reported incidence of infection of any kind.

Prochymal significantly decreased the levels of CRP compared to placebo in those patients with elevated CRP (>4 mg/L) at the time of study entry (p<0.05). The difference from placebo was evident at ten days post initial infusion, and was maintained throughout the treatment and follow-up period. CRP is a protein found in the blood in response to inflammation and is often elevated in inflammatory diseases such as GvHD and Crohn's disease, and has been found to correlate with clinical parameters of disease activity. Although there is substantial preclinical evidence, this study provides the first well-controlled objective data confirming the systemic anti-inflammatory effects of Prochymal in humans. Pulmonary function tests such as FEV1 and DLCO or carbon monoxide diffusing capacity of the lung were not improved over placebo following treatment with Prochymal at six months. FEV1 or forced expiratory volume is the amount of air that can forcibly be blown out of the lungs in the first second of exhalation. Although not reaching statistical significance, treatment with Prochymal did produce positive trends in exploratory functional endpoints such as the six-minute walk test and certain cardiac related parameters, particularly in patients with less established COPD. The trial will continue as planned and patients will be followed for the balance of the two-year evaluation period.

Prochymal is a preparation of mesenchymal stem cells specially formulated for intravenous infusion.

Osiris Therapeutics is the leading stem cell therapeutic company focused on developing products to treat serious medical conditions in the inflammatory, orthopedic and cardiovascular areas.