(Washington) A treatment has shown to slow the progression of Parkinson’s motor symptoms in a clinical trial in patients at an early stage of the disease, a result described as a first although it remains to be confirmed in a larger study.
The clinical trial sought to answer “a question that we have been struggling with for 30 years”, namely identifying a treatment capable of slowing the progression of the disease, Olivier Rascol, neuro-pharmacologist, told AFP. at Toulouse University Hospital and co-author of the study, published Wednesday in the American scientific journal NEJM.
“Industrialists have spent hundreds of millions of dollars […] for 30 years, doing clinical trials with the same objective, and they have never managed to obtain a result like ours,” he said.
The drug tested here, lixisenatide, developed by the French laboratory Sanofi, is already used against type 2 diabetes.
It belongs to a class of drugs (called GLP-1 receptor agonists) for which evidence has led scientists to believe that they could be beneficial against Parkinson’s.
This neurodegenerative disease affects around 10 million people worldwide. In particular, it causes motor skills problems (tremors, slowness of movements, etc.) and can ultimately prove very disabling in daily life.
It results from the progressive disappearance in the brain of neurons producing dopamine. The medications that exist today correct this lack of dopamine, but do not prevent the symptoms from worsening over the years, because they do not address their cause.
Scientists are therefore seeking to identify a treatment having a neuroprotective effect, that is to say improving the survival of dopamine-producing neurons.
The clinical trial, partly financed by the French Ministry of Health, was carried out on 156 people aged 40 and 75, at the start of the disease. Half received a placebo, and the other half received the treatment, by subcutaneous injections.
They were then regularly monitored by a professional, assessing, for example, their walking, hand movements, etc.
After one year, the group receiving the placebo showed a worsening of the motor symptoms score of 3 points, while the score of the group treated with lixisenatide remained unchanged.
A “modest” result, according to the study, but which could have been greater if the patients had been followed longer, as Parkinson’s disease progresses slowly, argued Professor Olivier Rascol.
Those three points of difference were also “extremely close” to when patients typically start to feel a difference, he added.
Not reaching this threshold is a “failure”, however, commented for AFP Michael Okun, medical director of the Parkinson’s Foundation in the United States. Despite everything, this difference of three points, although “small”, “must attract our attention”, he added.
Side effects, particularly gastrointestinal, have been observed. The weight loss that may be caused by this class of medication must also be taken into account.
The researchers now hope to conduct a larger trial.