Safinamide as Add-On Therapy in Patients With Early Idiopathic Parkinson's Disease Treated With a Stable Dose of a Single Dopamine Agonist (12 Month Extension)

Inclusion Criteria: 1. The patient completed 24 weeks of treatment in Study 015, or if the patient discontinued prematurely, he/she returned for scheduled efficacy evaluations at Weeks 12 and 24 (Visits 6 and 8) as part of the Retrieved Dropout (RDO) population. 2. The patient was compliant with taking study medication in Study 015. 3. The patient is willing to participate in the study and signed an approved Informed Consent form. Exclusion Criteria: 1. The patient is experiencing clinically significant adverse events that would put the patient at risk for participating in the study. 2. The patient has shown clinically significant deterioration during participation in Study 015. 3. The patient discontinued Study 015 prematurely for any reason, and did not return for scheduled efficacy evaluations at Weeks 12 and 24 (Visits 6 and 8) in Study 015.