Prochymal: Preliminary Phase III data

Preliminary data from a double-blind, international Phase III trial in 260 patients showed that IV Prochymal twice weekly for 4 weeks missed the primary endpoint of significantly improving durable CR rate vs. placebo (35% vs. 30%, p=0.3). Prochymal also missed the primary endpoint vs. placebo in the per protocol population (n=179; 40% vs. 28%, p=0.087).

Osiris also analyzed data from subgroups prospectively defined by organ involvement. In patients with steroid-refractory liver GvHD (n=61) compared with placebo, Prochymal significantly improved response rate defined as objective improvement in at least 1 organ without worsening in any others (76% vs. 47%, p=0.026) and durable CR rate (29% vs. 5%, p=0.046). In patients with steroid-refractory gastrointestinal GvHD (n=71), Prochymal significantly improved response rates vs. placebo (88% vs. 64%, p=0.018), but did not significantly improver durable CR rate vs. placebo (43% vs. 36%). Based on the results, Osiris said it plans to file an amendment with FDA to its current expanded access program to broaden the entry criteria to include patients with severe GvHD of the liver. ...