A medicine similar to that used in “skinny jabs” may help slow the progression of symptoms of Parkinson’s disease, research suggests.
According to the Parkinson’s Foundationmore than 10 million people around the world live with Parkinson’s – a condition in which nerve cells in the brain are lost over time, causing problems with movement, balance and memory, among other things.
Although treatments are available to help manage symptoms, there is no cure.
In recent years, however, glucagon-like peptide 1 receptor agonists (or GLP-1R agonists) have caused excitement, with one such drug, a type 2 diabetes medication called exenatide, found to help slows the progression of motor symptoms in a small group of people with Parkinson’s.
Now researchers say another such drug, a type 2 diabetes medication called lixisenatide, appears to do the same, supporting the theory that Parkinson’s may be associated with insulin resistance in the brain.
Prof Wassilios Meissner, from the University Hospital of Bordeaux, a principal investigator of the study, said the results were exciting.
“We have to remain cautious about all the interpretation and about applicability at the current stage, but it’s really a very, very clear and strong signal that we’ve never seen, except [in the] exenatide trial,” he said.
GLP-1R agonists have gained notoriety for their use in managing type 2 diabetes and aiding weight loss, with semaglutide and liraglutide among the best-known agents.
However, unlike exenatide and lixisenatide, they do not cross easily into the brain, making them less likely candidates for use in the treatment of Parkinson’s.
Researchers in France wrote in the New England Journal of Medicine how they divided 156 people recently diagnosed with Parkinson’s into two equal-sized groups.
While both groups took their usual Parkinson’s medication, one group was given an additional daily injection of lixisenatide, while the other was given a placebo.
Before, during and after the study, participants underwent an examination of their motor symptoms and were given a score on a disease severity scale.
The results show that after 12 months, those given lixisenatide showed essentially no progression of motor problems, while those given the placebo showed worsening symptoms, dropping about three points on the 132-point assessment scale – a modest difference, but still considered clinically significant.
The difference remained two months after the trial was stopped and other Parkinson’s medications were stopped overnight.
This, the researchers say, suggests that lixisenatide not only reduces symptoms, but protects the brain from the loss of neurons.
However, there was a downside, with about half of the participants receiving lixisenatide reporting nausea and 13% reporting vomiting.
The researchers add that further work is now needed to determine whether lixisenatide actually slows the progression of the disease itself, whether the benefits continue over time or even increase if the drugs are given for longer, the best dose and whether the drug benefits people will offer at other stages of Parkinson’s.
Heather Mortiboys, a professor of cellular neuroscience and metabolism at the University of Sheffield, who was not involved in the work, said the findings paved the way for larger phase 3 clinical trials.
“The new clinical trial results for lixisenatide showing a significant reduction in motor symptom progression compared to placebo groups represent a very promising and very exciting step forward in our research fight to find new medicines for Parkinson’s clinic,” she said. .
“The study adds more weight to all the current results showing that this class of drug, GLP-1R agonists, has real potential for Parkinson’s.”
