Osiris Therapeutics Prochymal, A Mesenchymal Stem Cell Product Derived From Bone Marrow, Approved For Marketing In Canada In Graft vs. Host Disease (GvHD)

Prochymal has been authorized for therapy in children with GvHD under Health Canada's Notice of Compliance with conditions (NOC/c) pathway, which provides access to therapeutic products that address unmet medical conditions and which have demonstrated a favorable risk/benefit profile in clinical trials. Under the NOC/c pathway, the sponsor must agree to carry out confirmatory clinical testing.

Both Osiris (OSIR) with Prochymal and Athersys Inc. (ATHX) with Multistem are in clinical trials with allogeneic GvHD stem cell therapies in the United States. Osiris concentrated on children after some issues arrose in its phase II clinical trial and has been aided in data presentation to Canadian authorities by Joanne Kurtzberg of Duke University. Athersys has not yet begun Phase II but has completed Phase I with good results.

Health Canada’s authorization was made following the recommendation of an independent expert advisory panel, commissioned to evaluate Prochymal's safety and efficacy. In Canada, Prochymal is now authorized for the management of acute GvHD in children who fail to respond to steroids.

The approval was based on the results from clinical studies evaluating Prochymal in patients with severe refractory acute GvHD.

Prochymal demonstrated a clinically meaningful response at 28 days post initiation of therapy in 61-64 percent of patients treated. Additionally, treatment with Prochymal resulted in a statistically significant improvement in survival when compared to a historical control population of pediatric patients with refractory GvHD (p=0.028). The survival benefit was most pronounced in patients with the most severe forms of GvHD.

As a condition of approval, the clinical benefit of Prochymal will be further evaluated in a case matched confirmatory trial and all patients receiving Prochymal will be encouraged to participate in a registry that will monitor the long-term effects of the therapy.

Athersys Inc., along with Osiris one of our Sector Companies, has completed a Phase I clinical trial with its product Multistem tested for safety in GvHD. Athersys met with the FDA in April and is now in conversation with the FDA concerning the structure of a Phase II trial.