4/29/10

Multiple Sclerosis research showing promise: Canadian stem cell study

(Posted By: Josi Creek)
But the 35-year-old Windsor, Ont.-born MS patient says the experimental stem-cell procedure seemed the best option when weighed against the prognosis for his rapidly worsening condition.

"It was a heavy decision," Prentice said from his temporary home in Ottawa. "It took a lot of thought and meditation, for sure."

The treatment was only available in Canada through a medical study being conducted in Ottawa. Prentice was the last of 24 MS patients who volunteered as trial subjects.

Part of the criteria for joining the study — launched in October 2000 — was that the patients have aggressive MS and were likely to become severely disabled.

The MS Society of Canada, which funded the study, states that the bone marrow transplants have generally been "well tolerated."

But the MS Society also warns that "each step of this treatment carries a risk of serious complications. These may be severe enough in a small percentage of patients to be fatal."

One trial subject died as a result of liver toxicity, leading to changes in the study's protocol.

"There are risks involved in any medical procedure," Prentice said. "That definitely gave me pause. But MS is just so wicked, it affects you so much, you're constantly getting worse."

The study investigates theories that an immune system afflicted with MS can be reset.

Stem cells are harvested from the patient's blood. Next, the patient's immune system is destroyed through intense chemotherapy. Then the stem cells are reintroduced with the hope that when the immune system grows back, it will no longer attack the nervous system.

"Kind of like rebooting a computer," Prentice said.

Neurologist Dr. Mark Freedman and bone marrow transplant specialist Dr. Harold Atkins are the lead investigators of the study.

Freedman said the treatment does not explain what exactly goes wrong with the immune system in MS, but it tests the idea that the error will not repeat itself if the immune system is replaced.

No new MS-related lesions have been detected in any of the trial subjects since they underwent the treatment. Some have even experienced improvement of their MS symptoms.

"The inflammatory nature of the disease has virtually ceased in everyone who has received this transplant," Freedman said. "I hate to use the 'C-word' — cure — but we've induced a very long-lasting remission."

Freedman also said the procedure has become safer over its 10-year history.

The study is now closed. But Freedman said he and Atkins plan on releasing their definitive publication about it later this year, and they're hopeful for government funding to continue refining the procedure. There is also interest in the study from the global medical community.

"I'm gratified in many ways," Freedman said, noting that the trial subjects would have succumbed to MS were it not for the study.

"Aaron can thank himself, and we thank him, certainly, for having the courage to take part in this experiment."