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| Human stem cell therapy could be on market in four years, researcher saysBy Tom Henderson| | | | | |If trials on humans go the way they did on rats and pigs, a stem cell therapy to treat patients with Lou Gehrig's disease could be on the market in four years, said Karl Johe, the chief science officer at Rockville, Md.-based Neuralstem Inc., following a presentation at the sixth annual World Stem Cell Summit in downtown Detroit.NeuralStem is providing neural stem cells for a Phase I U.S. Food and Drug Administration study at Emory University Hospital in Atlanta, in conjunction with Dr. Eva Feldman, director of the A. Alfred Taubman Medical Research Institute at the University of Michigan.So far, six patients with Lou Gehrig's disease have received injections of stem cells directly into their spinal cord.A former colleague of Feldman's at UM who is now a surgeon at Emory, Dr. Nicholas Boulis, has done all the operations.A seventh operation will be conducted this month. Phase I studies are to determine safety with Phase II and III studies needed to prove efficacy before FDA approval to take the procedure to the marketplace.“We know it works in rats and we know it works in pigs. We just don't know if it works in humans,” said Feldman.The current trial is scheduled to do one operation a month.When the surgeries are completed ina year, there will up to 12 months of observations of patients for such side effects as tumor creation or rejection of the implanted cells. Patients get up to 10 injections of 50,000 stem cells at each injection site during their operation.Johe said once the FDA is convinced the procedure is safe, the following two trials should take no more than a total of 18 months, followed by six months of review of data by the FDA.“So we're talking about possibly being in the market in four years,” hesaid.The Phase I trial began with severely affected, nonambulatory patients. It will proceed through increasingly healthy patients. It is healthier patients who will have more chance of showing slight to moderate side effects such as muscle weakness.Two major hurdles have already been cleared.It took years for NeuralStem to improve its process for growing stemcells following a donation by a patient in 2002 of spinal cord tissue.And Boulis had to design and make adevice that would hold the injecting needle perfectly in place as the patient breathed during the slow injection of the 50,000 cells per site. If the needle didn't move in perfect coordination with the spine, it would cause more spinal injury.Johe said that the company can now grow neural stem cells so quickly that in four months it can go from one million cells to 10 to the 24th power, which is one followed by 24 zeros.“From a single cell line we can treat millions and millions of people around the world,” he said.He showed slides of pigs with spinal cord injury that had been injected with stem cells. The injected cells quickly grew in and around the affected area and restored function.“Think of these as new wires for the body's circuitry that can mend broken wires,” he said. “We expect these wires to last forever.”Johe said his company has applied tothe FDA to begin Phase I studies of patients with spinal cord injuries.Boulis said other targets for injectingstem cells are multiple sclerosis, Huntington's, Parkinson's and Alzheimer's.Some treatments — such as those for stroke patients — would require major technical hurdles to be overcome.For example, a system would have tobe devised to get stem cells dispersed over a much larger area without getting them to places you don't want them, said Boulis.Other diseases, such as MS, would seem much easier.“You can see the damage. You can target it. We're not asking stem cells to do much, just go in and wrap around the nerves,” he said.Jon Glass, director of the Emory ALS Center, cautioned against too much exuberance, despite the success shown in rats and pigs.“We don't know if stem cells are going to work. We don't,” he said.While those involved in the study can't discuss anything but safety issues with the Phase I trial and not whether patients seem to be doing better, Feldman did show during a presentation Monday a clip from an interview with John Cornick, one of the first six patients in the study.He said that just a few days after his operation, he was once again able to do the buttons on his shirt. |
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发表于 2010-10-14 13:34
