The purpose of this study is to compare the effects of an experimental drug called prasinezumab in patients with early Parkinson's disease who are taking standard medication (either rasagiline, selegiline, or levodopa) to manage their disease symptoms. Participants will be randomly assigned to receive either prasinezumab or placebo (inactive substance). Prasinezumab is a type of medication called a monoclonal antibody. Prasinezumab may clear away harmful forms of a specific protein to prevent damage to brain cells, potentially slowing the course of Parkinson's disease.
A Phase IIb, Randomized, Double-Blind, Placebo-Controlled, Multicenter Study To Evaluate The Efficacy And Safety Of Intravenous Prasinezumab In Participants With Early Parkinson's Disease