Animal Study Demonstrates That
Gene Therapy Protects Key
Neurons From Degeneration
Associated With Parkinson`s
Disease Findings Have Potential
to Lead to New Treatment
August 6, 1997
COLLEGEVILLE, Pa., and ANTONY, France, Aug. 5
-- A study published today in the Proceedings
of the National Academy of Sciences shows that a new gene
therapy significantly improved survival of key neurons in an
animal model of Parkinson's disease. Researchers from RPR
Gencell, a division of Rhone-Poulenc Rorer (NYSE: RPR), and
Centre National de la Recherche Scientifique (CNRS)
demonstrated that recombinant adenovirus encoding glial-cell-line
derived neurotrophic factor (GDNF) significantly protected
neurons from degeneration and prevented behavioral deficits in a
rat model of Parkinson's disease.
"These results suggest that gene therapy is of therapeutic value
for Parkinson's disease," said Frederic Revah, Ph.D., coauthor of
the study and head of Central Nervous System R&D at RPR
Gencell. "This finding further supports the potential to lead to the
development of a treatment for Parkinson's disease based on the
use of recombinant adenoviral vectors encoding neurotrophic
factors."
GDNF is a neuroprotective agent previously shown to protect
dopaminergic neurons, which are specifically affected in
Parkinson's disease. However, GDNF does not normally cross the
blood-brain barrier. Gene transfer by local administration will
enable GDNF to be expressed inside the brain, thus circumventing
the blood-brain barrier. The blood-brain barrier is a selective
mechanism that impedes the passage of most ions and
large-molecular-weight compounds from the blood to the brain
tissue.
Scientists from RPR and Centre National de la Recherche
Scientifique have constructed a vector allowing the transfer of the
gene encoding GDNF to reach the brain via a genetically modified
adenovirus. Scientists injected this vector into the rat brain region
corresponding to the region normally affected in Parkinson's
patients.
This gene therapy was found to protect dopaminergic neurons
from the effects of a toxin that normally causes cell death. It also
prevented the motor deficits that result from dopaminergic neuron
degeneration.
Dopamine, which is one of the substances used by neurons to
transmit impulses (neurotransmitters), is normally produced in a
part of the brain that participates in the control of movement (the
basal ganglia). In Parkinson's disease patients, deterioration of
this area of the brain reduces the amount of dopamine and other
transmitters, such as acetylcholine. Without dopamine, the nerve
cells cannot properly transmit messages, and this results in
impairment of motor functions. The exact reason that the cells of
the brain degenerate is unknown.
Parkinson's disease affects approximately 2 out of every 1,000
people and most often develops after the age of 50. It affects both
men and women and is one of the most common neurologic
disorders of the elderly.
RPR Gencell is the division of RPR dedicated to the discovery,
development, manufacture and commercialization of gene therapy
products. By linking leading biotechnology companies and
research organizations worldwide with its own internal
capabilities, RPR Gencell hopes to accelerate the development of
effective therapies for cancer, cardiovascular disease, central
nervous system disorders and asthma.
CNRS (Centre National de la Recherche Scientifique) is a national
basic scientific research organization in France.
Rhone-Poulenc Rorer (NYSE: RPR) is a global pharmaceutical
company dedicated to improving human health. In 1996, the
Company had sales of $5.42 billion and invested $882 million in
research and development.
SOURCE Rhone-Poulenc Rorer
/CONTACT: Bob Pearson, 610-454-3872, or Bettina Frey,
33-1-5571-7264, both of Rhone-Poulenc Rorer/ /Rhone-Poulenc
Rorer press releases available through Company News On-Call by
fax, 800-758-5804, ext. 764050, or at http://www.prnewswire.com /
(RPR)
