Thanks to a $4.2 million grant from the Michael J. Fox Foundation for Parkinson's Research (MJFF), RheoGene Inc. and the University of Pittsburgh Medical Center (UPMC) will be able to carry out further R&D as well as preliminary clinical trials for a gene therapy vector system with a regulatable "on switch" to treat Parkinson's disease.

Parkinson's Disease is a debilitating condition resulting when brain cells cease to produce dopamine, a chemical crucial for the cellular communication that controls muscle movement. Current therapy approaches involve simply replenishing dopamine stocks using the drug levodopa (L-dopa), or brain surgery to control tremors. However, these treatments generally only work temporarily and cannot halt the progression of the disease, which ultimately leads to disability.

Currently, there are at least three other gene therapy approaches already on clinical trials, aimed at providing a more permanent treatment. But RheoGene's approach is different in that there is no surgery involved, no viral vectors, and allows "switching-off" should there be adverse side-effects.

The development of gene therapy as a widespread therapeutic technique has been hampered by the lack of any way to time or finely adjust doses or to "turn off" a gene once it has begun expressing a protein in the brain. The RheoGene-led team will work to use RheoGene's RheoSwitch� Therapeutic System (RTS) as a safe and effective means to regulate both the level (dose) and timing of gene expression using an orally administered Activator Drug, or "on switch." The advent of RTS would provide an unprecedented safety mechanism by allowing gene expression to be completely shut off in the event of adverse side effects simply through withdrawal of the RheoGene proprietary Activator Drug.

RheoGene's project will initially focus on two genes:

(1) the gene coding for glial cell derived neurotrophic factor (GDNF), a naturally occurring protein that protects and stimulates regeneration of brain cells that secrete dopamine, and
(2) the gene that codes for L-amino acid decarboxylase (AADC), an enzyme involved in dopamine synthesis.

The researchers will identify which of the two genes will the RheoSwitch be more applicable to and therefore merit further development. If successful, this technology may also have other applications in gene therapy for other ailments, including cancer and diabetes.

"This project has the potential to revolutionize the clinical application of gene therapy --- not only for the millions of people with Parkinson's disease, but for countless numbers afflicted by other health ailments as well," said Deborah W. Brooks, MJFF president and CEO.

Sources: Michael J. Fox Foundation and RheoGene press releases.