The study, a Phase 2 clinical trial, used two doses of the investigational drug. Its safety already had been tested in healthy volunteers. The goal was to determine what might be a reasonable dose for a larger clinical trial in Parkinson's disease.
Unlike L-Dopa, which works through the brain's dopamine system, SYN115 interacts with the brain's adenosine A2a receptor. That receptor can modify the effects of the neurotransmitters glutamate and dopamine and is thought to be a potential therapeutic target not only for Parkinson's disease but also for insomnia, pain, drug addiction and depression.
"This study is important because it demonstrates this may be a useful approach for studying investigational drugs," says lead investigator Kevin J. Black, MD. "We were able to determine both that the drug gets into the brain to exert its effects and that it has a larger effect at a higher dose."
Black, a professor of psychiatry, of neurology, of neurobiology and of radiology, and his team used a new, FDA-approved type of perfusion MRI called arterial spin labeling (ASL), which uses MRI scans to measure blood flow in the brain. A similar technique uses positron emission tomography (PET) scans. Older forms of MRI scanning could not provide scientists with similar functional measurements.
Although PET scans can measure many of the same things, a large number of medical centers don't have PET scanners, and depending how it's done, PET may cost more, Black explains. The previous method of measuring blood flow with functional MRI is called BOLD scanning (Blood Oxygen Level Dependent).
"That's a wonderful technique for watching someone's brain respond to a question or a task or to compare blood
|Contact: Jim Dryden|
Washington University School of Medicine