Clinical trial to test stem cell approach for children with brain injury
By University of Texas Health Science Center
Dec 23, 2005, 03:07
A unique clinical trial will gauge the safety and potential of treating children suffering traumatic brain injury with stem cells derived from their own bone marrow starting early next year at The University of Texas Medical School at Houston and Memorial Hermann Children's Hospital.
The clinical trial is the first to apply stem cells to treat traumatic brain injury. It does not involve embryonic stem cells.
"There is no reparative treatment for traumatic brain injury," said principal investigator Charles Cox, M.D., The Children's Fund, Inc. Distinguished Professor in Pediatric Surgery and Trauma at the medical school. "All we can do now is try to prevent secondary damage by relieving pressure on the brain caused by the initial injury."
Unlike bone, muscle and other organs, the brain does not repair itself effectively. Traumatic brain injury victims can regain some function through rehabilitation. Studies show between 15 and 25 percent of children suffering severe traumatic brain injury die, and survivors of even moderate injury often are devastated for life.
Approved by the U.S. Food and Drug Administration and the university's Committee for the Protection of Human Subjects (CPHS), the clinical trial builds on laboratory and animal research indicating that bone-marrow derived stem cells can migrate to an injured area of the brain, differentiate into new neurons and support cells, and induce brain repair.
"This would be an absolutely novel treatment, the first ever with potential to repair a traumatically damaged brain," said James Baumgartner, M.D., associate professor of pediatric neurosurgery and co-principal investigator on the project.
As a Phase I clinical trial, the project's first emphasis is to establish the safety of the procedure, with a secondary goal of observing possible therapeutic effects.
Cox and Baumgartner have permission to recruit 10 head injury patients to the study between the ages of 5 and 14 who meet criteria set for enrollment. After initial treatment and evaluation, a pediatric surgeon will approach the injured child's parents to explain the trial and request permission to enroll the child in the study.
If permission is granted, bone marrow will be extracted from the child's hip and then processed to derive two types of progenitor stem cells: mesenchymal stem cells, which differentiate into bone, cartilage and fat cells, and research indicates can also differentiate into neurons; and hematopoietic stem cells, which form all the cells needed for blood.
Preclinical research indicates that the mesenchymal stem cells play the major role in producing new neurons and support cells.
The Center for Cell and Gene Therapy at Baylor College of Medicine will process the bone marrow into the stem cell preparation and return it to Memorial Hermann Children's Hospital, where it will be given intravenously to the injured child.
All of this will be accomplished within 48 hours of the injury, Cox said. The children will be carefully monitored throughout for possible side effects. They will be evaluated for brain function one month and six months after the procedure to see if it is improved compared with historical data on the brain function of children of similar age who suffered a similar injury.
Safety trials involve too few patients to draw broad conclusions about the effectiveness of treatment. But they can set the stage for larger-scale research.
"All the preclinical data suggest this is a safe procedure with substantial information suggesting a possible treatment effect," Cox said.
Because the children are receiving their own cells, an immunological response to the treatment is unlikely.
Even marginal improvement could mean a great deal to someone who suffers a brain injury. "It could be the difference between being able to recognize your loved ones and not being able to, or between doing things for yourself or having to rely on others. That would be a huge impact on families and on society," Cox said.
Trauma is far and away the main cause of death and disability among children, and the main reason children die from trauma is brain injury, Cox said.
The proposal was under review for a year. The U.S. Food and Drug Administration approved Cox's Investigational New Drug (IND) application in September. The UT-Houston CPHS, the university's institutional review board for research projects, approved the project in November and will continue to monitor it.
The project is funded by the Memorial Hermann Foundation, internal research funds from The Office of the President at The University of Texas Health Science Center at Houston, and the National Institute of Child Health and Development and the National Heart, Lung, and Blood Institute of the National Institutes of Health.
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