Donated stem cells gave children near death from tissue rejection disease a second chance, according to results Osiris Therapeutics presented to the American Society of Hematology this week.
Osiris gave its patented Prochymal therapy to 12 children whose life-sustaining bone marrow transplants had turned and attacked their own bodies. The last-ditch effort saved the lives of seven of those children, who otherwise had less than 100 days to live.
“In patients without hope, we had a 58 percent response rate. That?s really significant,” Osiris CEO Randal Mills said. “I?m just thrilled with the results.”
The patients were receiving bone marrow transplants for leukemia or genetic disorders and had the donated tissue attack their own bodies ? a condition called graft versus host disease (GvHD).
The first line of treatment ? immune-suppressing drugs with strong steroid injections ? works 35 percent of the time, according to the presentation. If that fails, doctors prescribe powerful immune suppressants that relieve less than 20 percent of patients. Children who don?t respond to either therapy have a 15 percent chance of surviving more than 100 days.
Osiris offered ProchymalT ? its delivery of bone marrow-derived mesenchymal stem cells ? as a “compassionate use” therapy for children who “have failed all reasonable alternatives,” Mills said. Mesenchymal stem cells ? one in 100,000 bone marrow cells ? actively seek out inflammation and stop immune reactions such as those involved in tissue rejection, according to the Osiris Web site.
That doesn?t mean the children?s underlying disease is cured, but at least it kept the treatment from killing them, Mills said. The patients, ages 5 to 15, received three to 21 intravenous infusions of ProchymalT, according to the presentation. In addition to the seven survivors, all patients were relieved of painful gastrointestinal complications of GvHD. Osiris is in phase III trials to prove the effectiveness of ProchymalT in adult GvHD as well as Crohn?s disease, Randal said, though the compassionate use results will not affect FDA evaluation of those results.
