How can we improve the design and endpoints of symptomatic and disease modifying clinical trials in Parkinson’s disease?

A narrative review of the design problems with disease modifying therapy and symptomatic therapy trials in Parkinson’s disease was performed. This reaches the conclusion that there needs to be a radical re-think of trial design based on a better understanding of the pathophysiology of Parkinson’s disease. This will lead to a new generation of potentially neuroprotective agents. Biomarkers need to be developed which faithfully follow the progression of the disease. The problems caused by the symptomatic effects of therapies may mean that wash out and delayed start design trials have to be abandoned. Large pragmatic disease modifying therapy trials will be required.Symptomatic therapy trials in early and later Parkinson’s disease must be larger, longer and include an older more representative population of patients. Outcome measures with meaning to patients should be used, such as quality of life scales, and health economics analyses integral to trials should become the norm.