Osiris Therapeutics’ adult stem cell therapy Prochymal® received approval from Health Canada for the treatment of acute graft-vs-host disease (GvHD) in children who failed to respond to steroids. The company will have to carry out certain post-launch confirmatory studies.
The decision gives Osiris the distinction of being the first company to win full marketing approval of a stem cell product. Prochymal is an off-the-shelf human mesenchymal stem cell (MSC) therapy. Osiris’ stock jumped as high as $5.926 in early morning trading today after closing yesterday at $5.26.
The company’s plans for an FDA approval and U.S. launch of Prochymal for GvHD in 2010 were botched due to two clinical trial failures in that indication during 2009. FDA has asked for additional data before considering a sanction. Osiris expects to have new information and apply for FDA approval by the end of this year. Prochymal is used in eight countries including the U.S. on an expanded-access program basis, according to Bloomberg.
Prochymal was authorized under Health Canada's Notice of Compliance with conditions (NOC/c) pathway. It provides access to products that address unmet medical conditions and which have demonstrated a favorable risk/benefit profile in clinical trials.
“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, M.D., clinical associate professor, department of medicine and oncology at the University of Calgary, Canada, and principal investigator in the Phase III program for Prochymal. “Much like the introduction of antibiotics in the late 1920s, with stem cells we have now officially taken the first step into this new paradigm of medicine.”
Health Canada’s decision was based on 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% of patients treated. Furthermore, treatment with Prochymal resulted in 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. 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.
Osiris’ intellectual property protection for Prochymal includes 48 issued patents. Health Canada's decision will also provide Prochymal with regulatory exclusivity within the territory for eight years and an additional six-month extension is available since it addresses a pediatric population.
“While today marks the first approval of a stem cell drug, now that the door has been opened, it will surely not be the last,” notes C. Randal Mills, Ph.D., president and CEO of Osiris. That’s a nice rebound from the blow the stem cell therapeutic segment received last year when pioneer Geron decided to nix Phase III trials and exit the stem cell space. Geron, however, was working with embryonic stem cells. It was testing GRNOPC1, a population of living cells containing precursors to oligodendrocytes, as a treatment for spinal cord injuries.
Adult stem cell developers are having better luck. Osiris is evaluating Prochymal in Crohn disease, and has another MSC product, Chrondogen, that’s being tested as a treatment for Chondrogen is currently being evaluated in clinical trials for the treatment of osteoarthritis in the knee. Other contenders include Athersys, Celgene, Cytori, StemCells, and TCA Cellular Therapy.