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First stem cells to be used to treat fatal brain disease
By Betsy Mason
Contra Costa Times (Walnut Creek, CA)
22 September 2006
PALO ALTO
The first clinical trial to transplant stem cells to treat a brain disease is set to get underway this year.
The treatment involves injecting fetal brain stem cells into the brains of children with the devastating genetic disorder known as Batten disease, which usually results in death before the age of 12. The stem cells that will be used in the trial are produced by Palo Alto-based StemCells Inc.
"It is our hope, and the hope of many others, that this clinical trial will provide insight into a potential treatment option for this tragic disease," trial leader Robert Steiner said at a telephone press conference Friday. Steiner is with Oregon Health & Science University in Portland where the treatment will take place.
Previous trials, such as those for Parkinson's disease and spinal cord injuries, used more mature brain cells that were already on their way to becoming a specific type of cell, such as a neuron.
Brain stem cells have not yet taken the first steps toward becoming a specific type of brain cell, and still have the potential to become many different types of cells.
"It's the first trial that plans to use actual stem cells rather than their differentiated products," said Arnold Kriegstein, director of the Institute for Stem Cell and Tissue Biology at UC San Francisco, which is not involved with the trial.
The StemCells Inc. cells to be used in the trial are not embryonic stem cells, which come from embryos just a few days old. Instead, they come from fetal brain tissue, acquired with the mother's consent, and are considered adult stem cells.
"These cells are not genetically modified in any way, and they are not grown on any animal feeder cells," said Alan Jacobs of StemCells Inc.
Some other stem cell lines have been grown on mouse feeder cells which could make them unusable for human transplantation.
The company is looking into the potential for their brain stem cells to be used to treat other brain diseases and spinal cord injuries, Jacobs said.
In the current trial, six children between the ages of 2 and 12 suffering from Batten disease will be injected with the brain stem cells.
Batten disease is extremely rare, striking just one in 100,000 children, and is invariably fatal. People with the disease are missing enzymes that clear certain fatty substances from brain cells. Buildup of these fats damages different parts of the brain and leads to seizures, blindness, loss of the ability to walk and speak and eventually death.
"I've seen first-hand the devastation of these diseases." said Steiner. "They eventually become bed-ridden and debilitated, and death is inexorable."
The children in the trial will have stem cells injected by needles directly into several different areas on both sides of the brain through holes drilled in the skull. A computerized map of each child's brain will help the surgeon guide the needles to the right spot.
"The hope is that these cells will work as delivery vehicles," Kriegstein said. "What you want is a cell that will disperse and distribute itself through the brain and then sit there pumping out the enzyme."
The first participant will be treated sometime before the end of the year and will be monitored for at least a month to assess the safety of the procedure before the next patient is treated. All of the patients will be closely monitored for a year after their treatment and then followed for several years beyond that.
"We think this is a very important first step in a ground-breaking process to bring this kind of technology to the forefront in order to help patients," said Nathan Selden of OHSU, the surgeon who will do the injections.
While they do hope the stem cells will help these children, the doctors emphasized that the primary goal of the study is to evaluate the safety of the treatment.
In experiments in mice that were missing the same enzymes as the patients with Batten disease, the human brain stem cells produced the missing enzyme and the mice lived longer than mice that didn't get human stem cells.
"The level of the enzyme climbs following transplantation" of the stem cells, Jacobs said. "In concert with this, there is a reduction in the amount of abnormal storage material that accumulates in the brains."
It is very difficult to predict if the cells will do the same in a human brain, Kriegstein said. Mouse brains are much smaller, and the cells might not spread as well in human children.
"That's a much larger territory to cover," he said.
There is also the fear that the stem cells' ability to multiply into more stem cells could cause them to grow tumors.
Kriegstein is skeptical that the children in this trial will benefit significantly from the treatment, but stem cell researchers all over the world will be watching to see if injecting these stem cells is safe.
"We'll hope to learn from this trial quite a lot," Kriegstein said.
The scientists running the trial said they are not likely to divulge any information about the trial until after it is over because of the highly sensitive nature of the trial and to protect the privacy of the children and families involved.
Reach Betsy Mason at bmason@cctimes.com or 925-847-2158.
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