Osiris completes enrollment in Phase III graft versus host disease trial

Osiris Therapeutics, a stem cell therapeutic company, has completed patient enrollment in its pivotal, Phase III trial evaluating Prochymal as a first-line treatment for acute graft versus host disease, a life-threatening complication of bone-marrow transplantation.

The Phase III double-blind, placebo-controlled trial will evaluate the safety and efficacy of Prochymal in conjunction with steroid therapy in patients with newly diagnosed acute graft versus host disease (GvHD), grades B-D. The target enrollment for the trial was 184 patients.

The primary endpoint of the trial is the proportion of patients surviving at least 90 days that achieve a complete response when Prochymal is added to steroid therapy as compared to those receiving steroids alone. Patients are considered treatment failures if they do not achieve a complete response within 28 days of initiating treatment, if the steroid dose is increased or other immunosuppressive agents are added, or if the patient does not survive 90 days following initial treatment.

The double-blind, placebo-controlled trial enrolled 190 patients from 52 transplant centers across the US, Canada and Australia. Osiris has now completed enrollment in two pivotal stem cell trials in GvHD and expects top-line data from both studies in the second half of 2009. Additionally, the company has confirmed with the FDA, receipt of the first portions of its biological license application for Prochymal as part of a rolling submission.

Lode Debrabandere, senior vice president of therapeutics at Osiris, said: Completing patient enrollment in this second trial and initiating the application process with FDA are two important milestones for Osiris. GvHD has a very high mortality rate and today there are no approved treatments.

With over 400 patients participating between the two studies, we are compiling the largest data set ever assembled for this devastating disease. We appreciate all of the efforts of the FDA in the development of this first-in-class stem cell therapy.