The primary objective is to assess the long term safety and tolerability of sumanirole as measured by safety labs, ECG monitoring, vital signs, and adverse event reports in subjects with Parkinson's Disease who participated in previous sumanirole studies.

Inclusion Criteria:

• Idiopathic Parkinson's disease
• Modified Hoehn and Yahr Scale Stages 1-4
• Age over 30 years
• Previous participation in prior sumanirole studies

Exclusion Criteria:

• Use of dopamine agonist medications and other medications in defined timeframe
• Unstable dose of CNS active therapies (eg, hypnotics, antidepressants, anxiolytics) within the last 30 days
• Atypical Parkinson's syndromes due to drugs, metabolic disorders, encephalitis, or degenerative diseases
• Dementia
• History of active epilepsy within the past year
• Significant liver disease with defined laboratory criteria
• Significant renal disease with defined laboratory criteria
• Certain cardiac conditions
• Electroconvulsive therapy in the previous 90 days
• Subjects participating in other drug studies or receiving other investigational drugs within previous 30 days
• Positive pregnancy test at Screen
• Unwillingness to use adequate contraceptive methods
• Lactating women
• History of stereotaxic brain surgery
• Malignant melanoma or history of treated melanoma