Results from a phase 2 trial of lixisenatide have been published

Lixisenatide, a diabetes drug being investigated for Parkinson’s, shows potential to slow the progression of movement symptoms.

Clinical trial results show that movement symptoms in people with Parkinson’s receiving lixisenatide treatment did not deteriorate over a 12 month period, compared to those receiving a placebo where there was a slight worsening.

The results are from a study (LixiPark) of 156 people with Parkinson’s who were less than 3 years into their diagnosis. 75 people received daily injections of lixisenatide, and 75 people an inactive (placebo) injection, over 12 months. This was conducted  at multiple research sites across France and was supported by Cure Parkinson’s and the Van Andel Institute through the International Linked Clinical Trials programme.

What is lixisenatide?

Lixisenatide is currently used in the treatment of type 2 diabetes. It works by targeting glucagon-like peptide-1 (GLP-1) receptors in the pancreas, which causes the release of a hormone called insulin and results in increased uptake of glucose (a form of sugar) by cells.

It is being investigated for Parkinson’s because GLP-1 receptors are also found in the brain, and lab-based experiments have suggested that activating them can boost the function of dopamine connections, have anti-inflammatory properties, improve energy production, and switch on cell survival signals. Lixisenatide is the second diabetes drug to go through clinical trials for Parkinson’s. The other one being exenatide.

What do these results mean for people with Parkinson's? 

Clinical trial results from both drugs show their potential to slow motor symptom progression. But, similarly to the results from the most recent exenatide trial, people taking lixisenatide didn’t report any changes to their quality of life, or measurements of non-motor symptoms. This leaves unanswered questions about the potential of these drugs for people with Parkinson’s. A phase 3 study of exenatide is underway to help answer some of these questions.

You can read a summary of the scientific paper on the New England Journal of Medicine's website.

Professor David Dexter, Director of Research at Parkinson’s UK, said:

"The most significant part of these results are the lack of deterioration seen in the clinical measurement of motor symptoms in those receiving lixisenatide over the 12 months. This is promising, but from this study it's hard to say whether the drug is slowing the progression of the condition. A longer trial could be able to show this and could be a logical next step.

“It will be interesting to see the results from a similar drug called exenatide. Previous clinical trial results suggest it could be more beneficial than lixisenatide. The Parkinson's community urgently needs new treatments so they, and we, eagerly await the results from this ongoing phase 3 trial, expected later this year.”

What’s the connection between diabetes and Parkinson’s?

Read more about the promise of repurposing diabetes drugs for Parkinson’s. This includes research results from previous clinical trials.