Type 2 diabetes drug may be key to stopping Parkinson’s progression
A drug that is normally used to treat type 2 diabetes may hold the key to stopping the progression of Parkinson’s disease, a clinical trial suggests.
Current drugs help manage the symptoms, but do not prevent brain cells dying. But a trial conducted on 62 patients by a team from the University College London (UCL) in the UK hints at the possibility that the medicine halted progression of the disease.
The team is “excited”, but it urges caution as any long-term benefit is uncertain and the drug needs more testing.
Professor Tom Foltynie, one of the researchers, said in an interview that there is absolutely no doubt the most important unmet need in Parkinson’s is a drug to slow down disease progression.
In Parkinson’s, the brain is progressively damaged and the cells that produce the hormone dopamine are lost. It leads to a tremor, difficulty moving and eventually memory problems.
Therapies help manage symptoms by boosting dopamine levels, but the death of the brain continues and the disease gets worse. There is currently no drug available that can stop that from happening.
In the trial, half of patients were given the diabetes drug exenatide and the rest were given a placebo (dummy treatment). All the patients stayed on their usual medication.
As expected, those on just their usual medication declined over 48 weeks of treatment. But those given exenatide were stable.And three months after the experimental treatment stopped, those who had been taking exenatide were still better off.
Professor Foltynie said the study was the first clinical trial in actual patients with Parkinson’s where there has been anything like this size of effect, which gives them confidence that exenatide is not just masking symptoms but is actually doing something to the underlying disease.
He said they need to be excited and encouraged, but also cautious as they need to replicate their findings.They also need to trial the drug for much longer periods of time.
An effective drug would need to hold back the disease for years in order to make a significant difference to patients.
Parkinson’s progresses slowly and the difference in this 60-week trial was definitely there, but was “trivial” in terms of the impact on day-to-day life, say the researchers.
The drug helps control blood sugar levels in diabetes by acting on a hormone sensor called GLP-1.
Those sensors are found in brain cells too. It is thought the drug makes those cells work more efficiently or helps them to survive.
It is why the drug is being tested in other neurodegenerative diseases including Alzheimer’s.
David Dexter, the deputy director of research at Parkinson’s UK, said: “The findings offer hope that drugs like exenatide can slow the course of Parkinson’s – something no current treatment can do.
“Because Parkinson’s can progress quite gradually, this study was probably too small and short to tell us whether exenatide can halt the progression of the condition, but it’s certainly encouraging and warrants further investigation.”