Sunday, 20 May 2012 07:00
Prochymal is only approved treatment for GvHD.
Osiris Therapeutics said it has received approval from Health Canada to market its stem cell therapy Prochymal for the treatment of acute graft-vs-host disease in children. The company says the decision makes Prochymal the world’s first approved manufactured stem cell product and the first therapy to be approved to treat GvHD.
GvHD is an often fatal complication from bone marrow transplants caused by immune system T-cells in the transplanted marrow attacking the host. It is a painful condition that can cause blistering of the skin, bleeding in the intestines, and in severe cases causes death in up to 80 percent of the children affected, often within weeks of a diagnosis. Steroids are used as first-line therapy to treat GvHD, but the success rate is only between 30 percent and 50 percent. If steroids fail, doctors typically turn to off-label use of immunosuppressive agents, which offer little benefit and significant toxicities.
“I am very proud of the leadership role Canada has taken in advancing stem cell therapy and particularly gratified that this historic decision benefits children who would otherwise have little hope,” says Andrew Daly, a clinical associate professor in the Department of Medicine and Oncology at the University of Calgary, Canada and principal investigator in a late stage trial of Prochymal. “As a result of Health Canada’s comprehensive review, physicians now have an off-the-shelf stem cell therapy in their arsenal to fight GvHD. Much like the introduction of antibiotics in the late 1920's, with stem cells we have now officially taken the first step into this new paradigm of medicine.”
Osiris’ Prochymal is an off-the-shelf product that does not require patient typing or matching. It is derived from mesenchymal stem cells derived from the bone marrow of healthy adult donors. Though Canada is the only country to approve the therapy, it is available in eight other countries including the United States under an expanded access program.
The company expects to apply for regulatory approval in the United States this year. It is also conducting late-stage trials of Prochymal in refractory Crohn’s disease, and is testing Prochymal as a treatment for heart attack and type 1 diabetes.
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 28 days after initiation of therapy in 61 to 64 percent of patients treated and the company says patients tested displayed a statistically significant improvement in survival when compared to a historical control population of pediatric patients with refractory GvHD. The survival benefit was most pronounced in patients with the most severe forms of GvHD.
Health Canada is requiring that Osiris continue to evaluate the clinical benefits of Prochymal in a confirmatory trial. Patients using the drug will be encouraged to participate in a registry that will monitor the long-term effects of the therapy.
On a conference call discussing the approval with analysts, the company said that through its expanded access program it has been treating patients for some time in Canada. It says it has also developed solid relationships with all of the transplant centers and had a dedicated team already in place for its commercial launch. The company, however, did not address questions about pricing. It is currently going through reimbursement review process in Canada.
By DANIEL S. LEVINE