WASHINGTONThe National Institute of Neurological Disorders and Stroke (NINDS), part of the national Institutes of Health (NIH), launched a large-scale clinical trial in late March to investigate whether the nutritional supplement creatine can slow the progression of Parkinson's disease (PD). The double-blind, placebo-controlled, phase III study is one of the largest PD clinical trials to date; it will enroll 1720 people with early-stage PD at 52 medical centers in the United States and Canada. Participants will be in the phase III study for five to seven years.

Currently, no treatment has been shown to slow the progression of PD. Creatine, known for improved exercise benefits, is not an approved therapy for PD, but was identified by PD researchers through a new rapid method for screening potential therapeutic compounds. The hypothesis is creatine might not only fuel the mitochondria in cells, but may also protect certain brain cells from oxidative stress or damage. The institute noted animal studies have shown creatine is able to prevent loss of the cells typically affected.

"Creatine, or any compound that may slow the progression of PD, could have very important long-term benefits for people who are living with this disease," says John R. Marler, M.D., NINDS associate director for clinical trials.

The study will enroll people diagnosed with PD within the past five years and treated for two years or less with levodopa or other drugs that increase the levels of dopamine in the brainas many of the symptoms of PD result from the loss of dopamine, a neurotransmitter that helps to control movement. Half of the participants will receive creatine, and half will receive a placebo; neither the participants nor their doctors will know which treatment they receive.

We are studying a stage of the disease that usually hasn't been included in clinical studies," notes Karl Kieburtz, M.D., M.P.H., of the University of Rochester, N.Y., and lead researcher on the project. He will be assisted by Barbara C. Tilley, Ph.D., of the Medical University of South Carolina in Charleston. The patients will be seen by movement disorders specialists at sites across the United States and Canada.

The trial is the first large study in a series of NINDS-sponsored clinical trials called NET-PD (NIH Exploratory Trials in Parkinson's Disease), which uses a developmenetal processfrom lab to pilot then phase III study. According to the NINDS, this large network of clinical sites will allow researchers to work with PD patients over a long period of time, with a goal of finding effective and lasting treatments.

"This study is an important step toward developing a therapy that could change the course of this devastating disease," says Elias A. Zerhouni, M.D., director of the NIH. "The goal is to improve the quality of life for people with Parkinson's for a longer period of time than is possible with existing therapies."