GENE THERAPY COULD GIVE HOPE TO PARKINSON'S PATIENTS
WebPosted Thu Oct 26 15:14:48 2000

WASHINGTON--A gene transferred to the brains of monkeys was able to 
control symptoms of Parkinson's disease in the animals. Experts say the 
results offer "promise" for human patients. 

 Parkinson's disease is a progressive brain disorder affecting cells that 
make dopamine. The cause of the disease is not known, but this new gene 
therapy technique prompted the brains of monkeys to produce more of the 
brain chemical, thereby diminishing symptoms of the disease. 

 The technique uses a virus linked to a gene that triggers production of 
dopamine. 

 In the experiment, a group of Rhesus monkeys were given a drug, MPTP, 
that artificially induces Parkinson's disease symptoms. Ten of the 
monkeys developed pronounced symptoms. 

 Five in the group were then given the gene therapy injection into their 
brains. Five others received a placebo injection. One monkey in each 
group died of unknown causes after being injected. 

 Of the four remaining monkeys in the gene therapy group, three were 
totally relieved of the Parkinson's symptoms. The four control monkeys 
continued to show signs of the disease and became "severely impaired," 
said Jeffrey H. Kordower, first author on the study. 

 He said the beneficial effect lasted for at least eight months. The 
monkeys were then killed for a detailed analysis of their brains. 

 The study will appear in Friday's issue of Science . 

 Cautious optimism 

 Dr. Ted M. Dawson, head of the Parkinson's Disease Research Center at 
Johns Hopkins University Medical Center says while the experiment shows 
dramatic effects, he is only cautiously optimistic. 

 He says there are still questions about safety that would have to be 
answered before the gene therapy could be tried in humans. 

 Dr. Mark H. Tuszynski, head of a brain disorder research centre at the 
University of California, San Diego, says there is uncertainty about 
whether the brain cells affected by the chemically induced Parkinson's 
in monkeys are the same as those affected by the actual disease in 
humans. 

 Kordower said that another study in monkeys is under way to test the 
safety of the gene therapy. When that is completed in about six months, 
he said an application for human clinical trials would be prepared for 
presentation to the U.S. Food and Drug Administration. 

 But even if all of the studies go smoothly, said Kordower, it could take 
three to five years before the gene therapy is ready for testing in 
humans. 

 
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