MANHASSET, N.Y., Nov. 19 /PRNewswire-USNewswire/ -- Brain scans used to
track changes in a dozen patients who received an experimental gene therapy
show that the treatment normalizes brain function -- and the effects are
still present a year later.
Andrew Feigin, MD, and David Eidelberg, MD, of The Feinstein Institute
for Medical Research collaborated with Michael Kaplitt, MD, of Weill
Cornell Medical Center in Manhattan and others to deliver genes for
glutamic acid decarboxylase (or GAD) into the subthalamic nucleus of the
brain in Parkinson's patients. The study was designed as a phase I safety
study, and the genes were delivered to only one side of the brain to reduce
risk and to better assess the treatment.
A recently published study included the clinical results of the novel
gene therapy trial, but this new report from the same study focuses on the
power of modern brain scans to show that the gene therapy altered brain
activity in a favorable way. This latest study is published this week in
the Proceedings of the National Academy of Sciences.
The patients only received the viral vector-carrying genes to the side
of the brain that controls movement on the side of their body most affected
by the disease. It was a so-called open-label study -- everybody received
the gene therapy so the scientists knew that there could be a placebo
effect. That is why brain scans were so critical to the experiment. Dr.
Eidelberg and his colleagues pioneered the technology and used it to
identify brain networks in Parkinson's disease and a number of other
In Parkinson's, they identified two discrete brain networks -- one that
regulates movement and another that affects cognition. The results from the
brain scan study on the gene therapy patients show that only the motor
networks were altered by the therapy. "This is good news," said Dr.
Eidelberg, the senior investigator of the study. "You want to be sure that
the treatment doesn't make things worse." The gene makes an inhibitory
chemical called GABA that turns down the activity in a key node of the
Parkinson's motor network. The investigators were not expecting to see
changes in cognition, and the scans confirmed that this did not occur.
Position emission tomography (PET) scans were performed before the
surgery and repeated six months later and then again one year after the
surgery. The motor network on the untreated side of the body got worse, and
the treated side got better. The level of improvements in the motor network
correlated with increased clinical ratings of patient disability, added Dr.
"Having this information from a PET scan allows us to know that what we
are seeing is real," Dr. Eidelberg added. The scans also detected
differences in responses between dose groups, with the highest gene therapy
dose demonstrating a longer-lasting effect. "This study demonstrates that
PET scanning can be a valuable marker in testing novel therapies for
Parkinson's disease," he said.
The gene therapy technique was developed by Neurologix Inc., a New
Jersey-based company. Scientists are now working on a design for a phase 2
blinded study that would include a larger number of patients to test the
effectiveness of the treatment.
About The Feinstein Institute for Medical Research
The Feinstein Institute for Medical Research is home to international
scientific leaders in Parkinson's disease, Alzheimer's, psychiatric
disorders, rheumatoid arthritis, lupus, sepsis, inflammatory bowel disease,
diabetes, human genetics, leukemia, lymphoma, neuroimmunology, and
medicinal chemistry. Part of the North Shore-LIJ Health System, FIMR ranks
in the top 6th percentile of all National Institutes of Health grants
awarded to research centers. Feinstein researchers are developing new drugs
and drug targets, and producing results where science meets the patient.
For more information, please visit http://www.FeinsteinInstitute.org or the
Feinstein Institute's blog at
SOURCE The Feinstein Institute for Medical Research