People with Parkinson’s have a severe reduction in levels of a protein called dopamine in their brains.
Lower levels of dopamine are associated with the motor symptoms of the condition (slowness and rigidity of movement). Doctors prescribe treatments that replace this lost dopamine as a means of treating the condition and providing a better quality of life for people with Parkinson’s.
Unfortunately, dopamine itself cannot be given directly to patients because it is very unstable – it breaks down very quickly in the body. In addition, dopamine curiously has a very difficult time getting into the brain. As a result, doctors have used a drug called Levodopa (or L-dopa) to treat Parkinson’s. L-dopa is one of the ingredients required for the production of dopamine. It is stable, easily accesses the brain, and has been safely used for the last 50 years.
People with Parkinson’s will take L-dopa tablets several times a day to keep the levels of dopamine in their brains at a level which helps them to live relatively normal lives. However, this intermittent delivery of L-Dopa is not ideal because it causes fluctuations in the levels of dopamine in the body and, long term use of this medication has been associated with complications such as dyskinesias – abnormal or impaired voluntary movement.
New research, led by Prof. David Devos (University of Lille, France and member of Cure Parkinson’s supported international Linked Clinical Trials committee), proposes a continuous delivery of a more stable form of dopamine (‘A-dopamine’) directly into the brain. To test their approach, the researchers used a primate model of Parkinson’s and found that the continuous direct delivery of A-dopamine into the brain provided a better, more consistent method of treating the Parkinson’s symptoms than using the intermittent oral L-dopa treatment. Even at high doses, the researchers observed no dyskinesias or other treatment associated complications.
The researchers used this study to test the options available to define important safety information in preparation for a future proof of concept clinical trial in humans.
