Il Parkinson’s disease is a chronic neurodegenerative disease which affects the nervous system, causing the progressive loss of brain cells that produce dopamine. Dopamine deficiency leads to a variety of motor symptoms, including tremors, muscle stiffness, slowness of movement, and difficulty maintaining balance.
This neurodegenerative disease affects a significant number of people worldwide and is currently estimated to be affected between 7 and 10 million individuals globally and between 250,000 and 300,000 people in Italy. Most cases occur after age 60, but Parkinson’s disease can also affect younger individuals, with a small but significant percentage of cases developing before age 50.
Currently There is no definitive cure, but there are several established therapies and treatments available aimed at managing and mitigating symptoms, contributing overall to improving the quality of life of patients. Drug therapy may include the use of drugs that increase dopamine levels in the brain, such as levodopa, or that act on the nervous system to control symptoms. Other therapeutic approaches are in development and include gene therapy and stem cell therapy. Furthermore, Research efforts continue to develop new therapies and treatments that can slow the progression of the disease or even prevent it.
According to a new clinical study led by Olivier Rascol, a Parkinson’s disease researcher at the University Hospital of Toulouse in France, whose findings were published in New England Journal of Medicine lixisenatide, a glucagon-like peptide-1 (GLP-1) receptor agonist used in the treatment of diabetes, has demonstrated neuroprotective properties in a mouse model of Parkinson’s disease.
Several studies have shown a link between diabetes and Parkinson’s. People with diabetes are about 40% more likely to develop Parkinson’s. Additionally, people who have both Parkinson’s and diabetes often see a faster progression of symptoms than those who only have Parkinson’s.
Animal studies have suggested that some GLP-1 drugs, which affect insulin and glucose levels, can slow down Parkinson’s symptoms. Previous studies, published in 2013 and 2017, suggested that exenatide, another diabetes drug, might do the same in people.
The most recent study, led by Rascol, involved 156 participants with mild or moderate Parkinson’s symptoms who were already taking treatment with the standard Parkinson’s drug, levodopa, or other medications. For a year months, half of them took lixisenatide, the other half a placebo.
After 12 months, subjects in the control group who received the placebo showed worsening of symptoms. Specifically, their score had increased by three points on a scale used to rate the severity of Parkinson’s, which measures people’s ability to carry out activities such as talking, eating and walking. Participants who took the drug, however, did not experience changes in scores on this scale, an advantage in a condition characterized by the progressive loss of motor control. However, the treatment resulted in gastrointestinal side effects, such as nausea (in nearly half of patients) and vomiting in 13 percent of people who took the drug.
Further and larger studies are needed to monitor side effects, determine the best dose and safety of lixisenatide in people with Parkinson’s disease, but researchers say that the trial marks a promising step in the decades-long effort to address this common and debilitating disorder. “This is the first large-scale, multicenter clinical trial to provide the signals of efficacy that have been sought for so many years,” says Rascol. Caution, given the long history of attempts that ultimately did not work in the search for a cure, remains a must but the prospects that concern not only lixisenatide but also other more recent drugs of the GLP-1 class (lixisenatide has been developed in the 2000s) are of great interest and potential. “More recent drugs,” underlines David Standaert, a neurologist at the University of Alabama at Birmingham who did not participate in the study consulted by Nature in this regard, “they may offer fewer and milder side effects or work at lower doses.”