Is Exenatide a Treatment for Parkinson's Disease?

There is growing interest in the use of glucagon-like peptide-1 agonists as treatments for Parkinson's disease following the recent publication of the results of the Exenatide-PD trial. In this randomized, double-blind, placebo controlled trial, patients with moderate stage Parkinson's disease treated with once-weekly subcutaneous injections of exenatide 2 mg (Bydureon) for 48 weeks, had a 3.5-point advantage over the placebo group in the Movement Disorders Society Unified Parkinson's Disease Rating Scale (MDS-UPDRS) motor subscale (Part 3) in the practically defined OFF medication state, 12 weeks after cessation of the trial drug. In this article, we discuss some of the important issues of relevance to this trial, with regards to trial design, patient selection, choice of outcome measure and also place into context the implications these results have for patients with Parkinson's disease and the wider research community.