A phase III, double-blind, placebo-controlled extension trial to investigate the long-term efficacy and safety of low (50 mg/day) and high (100 mg/day) dose safinamide, as add-on therapy in subjects with early idiopathic Parkinson's disease treated with a stable dose of a single dopamine agonist

INTERVENTION: Intervention1: Safinamide: Safinamide 50 mg at Weeks 12, 24, 36, 48, 60 and 78 Control Intervention1: Safinamide: safinamide 100 mg Weeks 12, 24, 36, 48, 60 and 78 Control Intervention2: Placebo: Weeks 12, 24, 36, 48, 60 and 78 CONDITION: Idiopathic Parkinson's Disease PRIMARY OUTCOME: Change in the dose of DA‐agonist; addition of another DA‐agonist, levodopa, or other PD therapy; or discontinuation due to lack of efficacy‐‐‐‐‐‐Timepoint: Time from baseline to first intervention SECONDARY OUTCOME: Proportion of subjects requiring intervention; ? UPDRS Section III (motor) score change from baseline to W78; ? UPDRS Section II (ADL) score change from baseline to W78; ? CGI ? Change scale score, change from Day 0 of Trial 27918 to W78; ? CGI ? Severity scale score change from baseline to W78EQ‐5D score change from baseline to W78; ? PDQ‐39 score change from baseline to W78; ? Cogtest® PD battery test score change from baseline to W78; ‐‐‐‐‐‐Timepoint: From baseline to Week 78 INCLUSION CRITERIA: INCLUSION CRITERIA: To be eligible for inclusion into this trial, the subjects must fulfill all of the following criteria: 1. The subject completed 24 weeks of Trial 27918. 2. The subject successfully completed all trial requirements in Trial 27918. 3. If female, they must be either post‐menopausal for at least 2 years, surgically sterilized or have undergone hysterectomy or, if of child bearing potential they must be willing to avoid pregnancy by using an adequate method of contraception for four weeks prior to, during and four weeks after the last dose of trial medication. For the purposes of this trial, women of childbearing potential are defined as: ?All female subjects after puberty unless they are post‐menopausal for at least two years, are surgically sterile or are sexually inactive?. 4. Subject is willing and able to participate in the trial and has provided written, informed consent