A Multicenter, Randomized, Double-blind, Placebo-controlled, Parallel Group Study of SLV308 as Adjunct Therapy to Levodopa in Patients With Parkinson's Disease Experiencing Motor Fluctuations.

This study is a multicenter, randomized, double blind, parallel group study of 3 months' treatment with SLV308 administered as a monotherapy in patients with advance stage PD. An open label safety extension to this study is planned as a separate protocol for patients who are willing and eligible to participate.