A Randomized, Double-Blind, Placebo-Controlled, Phase IIa, Parallel Group, Two Cohort Study to Define the Safety, Tolerability, Clinical and Exploratory Biological Activity of the Chronic Administration of Nilotinib in Participants With Parkinson's Disease A Randomized, Double-Blind, Placebo-Controlled, Phase IIa, Parallel Group, Two Cohort Study to Defin ...