The GLP-1 receptor agonist exenatide failed to meet its primary outcome in a phase III trial of Parkinson's disease patients. Weekly injections of the GLP-1 receptor agonist exenatide (Byetta, Bydureon) did not slow Parkinson's disease progression or improve symptoms, the phase III Exenatide-PD3 trial showed.

The study may suggest that other researchers should be less optimistic about the prospects for treating a range of other conditions with newer weight-loss drugs.

Hopes that GLP-1 drugs such as Ozempic and Wegovy could help slow Parkinson's disease have taken an hit. A new study found that a drug in the same class called exenatide, marketed as Byetta, had no effect on slowing the disease or easing its symtoms.