Canada OKs World's 1st Stem Cell Therapy Prochymal may ease complication from bone marrow transplants By Neal Colgrass, Newser Staff Posted May 19, 2012 1:59 PM CDT 53 comments Comments Doctors perform a bone marrow harvest. (Shutterstock) (Newser) – Canada has approved the world's first stem cell treatment for a systemic disease, Reuters reports. This week, the nation's health regulators allowed doctors to use the drug Prochymal for children with graft-versus host disease (GvHD), a sometimes deadly side-effect from bone marrow transplants. GvHd kills up to 80% of afflicted children and has no approved treatment thus far. Some analysts doubted Prochymal's effect, noting that it accomplished no more than a placebo in two late-stage clinical trials. But regulators liked the way it helped a certain subgroup of patients, who saw an improvement in 61% to 64% of cases. The drug also improved survival rates across the board when compared with a a history of GvHD patients. A US company called Osiris makes the drug, and plans to seek FDA approval by the end of the year.