Canadian health regulators have approved stem cell treatment by Osiris Therapeutics Inc. for acute graft-versus host disease in children. This is the first stem cell drug ever to be approved for treating a systemic disease.
Graft versus host disease (GvHD) that often leads to death is a complication that occurs after the bone marrow transplantation, when implanted cells attack the recipient’s body. It can have various symptoms from skin rash to hair loss, digestive tract and lung disorders, vomiting, etc. The disease leads to death in 80 percent of children who have it. There are between 3,500 to 4,000 patients affected with the disease worldwide.
Given the complexity of the disease, there were no approved treatments for it up to date. Prochymal, that is how the stem cell drug by Osiris called, was the first approved by Canadian authorities for treating children who have not responded to steroid therapy. After it reaches market, it should undergo further testing, which is expected to take three to four years.
With regard to the stem cell treatment effectiveness, which was questioned by some experts, Osiris was able to demonstrate that 61-64 percent of children with severe refractory acute GvHD who had not responded to all other drugs demonstrated a clinical response one month after the therapy. Increased survival rate, if compared with historical control group of children with refractory GvHD, was also registered.
Prochymal is produced from adult bone marrow stem cells. Among its therapeutic effects are control of inflammation, tissue regeneration and scar formation prevention. To date, the researchers do not entirely understand how the drug works to help pediatric patients with GvHD.
Osiris plans also to get approval of the U.S. Food and Drug Administration to make it available in the US. In the Canadian market, it will have at least eight years of exclusivity. However, the competition in the field is rising, and that may bring new adult stem cell therapies to the market.