Study Evaluating Sumanirole for the Treatment of the Signs and Symptoms of Early Parkinson's Disease

Inclusion Criteria: Idiopathic Parkinson's disease \< 7 years duration Modified Hoehn and Yahr Scale Stages I through III Age greater than or equal to 30 years old Patients or their partners must use adequate contraceptive methods Patients who are willing and able to comply with scheduled visits, treatment plan, laboratory tests, and other study procedures and do not plan on traveling extensively during the study Exclusion Criteria: Atypical Parkinson's disease syndromes due to drugs, metabolic disorders, encephalitis, or degenerative diseases. Levodopa received for 1-year accumulated interval in the last two years. Dopamine agonist medications or catechol-o-methyl transferase inhibitors in the 30 days prior to baseline. Unstable dose regimes of hypnotics, anxiolytics or antidepressants Dementia History of stereotaxic brain surgery, psychosis or active epilepsy within past year. Participation in clinical trial within the previous 30 days. Malignant melanoma or history of melanoma Significant medical or pshychiatric condition