Cerebral dopamine neurotrophic factor(University of Helsinki)

This study evaluates the safety and tolerability of CDNF in patients with Parkinson's disease, when dosed directly into the brain using an implanted investigational drug delivery system (DDS). Safety and accuracy of the DDS is also being evaluated. One-third of the patients will receive monthly infusions with placebo and two-third of the patients will receive monthly infusions with either mid- or high-doses of CDNF for a period of 6 months.