Two-year, randomized, controlled study of safinamide as add-on to levodopa in mid to late Parkinson's disease.

In a 6-month double-blind, placebo-controlled study of Parkinson's disease patients with motor fluctuations, safinamide 50 and 100 mg/d significantly increased ON-time without increasing dyskinesia. Further long-term safinamide use in these patients was evaluated over an additional 18 months. Patients continued on their randomized placebo, 50, or 100 mg/d safinamide. The primary endpoint was change in Dyskinesia Rating Scale total score during ON-time over 24 months. Other efficacy endpoints included change in ON-time without troublesome dyskinesia, changes in individual diary categories, depressive symptoms, and quality of life measures. Change in Dyskinesia Rating Scale was not significantly different in safinamide versus placebo groups, despite decreased mean total Dyskinesia Rating Scale with safinamide compared with an almost unchanged score in placebo. Ad hoc subgroup analysis of moderate to severe dyskinetic patients at baseline (36% of patients) showed a decrease with safinamide 100 mg/d compared with placebo (P = 0.0317). Improvements in motor function, activities of daily living, depressive symptoms, clinical status, and quality of life at 6 months remained significant at 24 months. Adverse events and discontinuation rates were similar with safinamide and placebo. This 2-year, controlled study of add-on safinamide in mid-to-late Parkinson's disease with motor fluctuations, although not demonstrating an overall difference in dyskinesias between patients and controls, showed improvement in dyskinesia in patients at least moderately dyskinetic at baseline. The study additionally demonstrated significant clinical benefits in ON-time (without troublesome dyskinesia), OFF-time, activities of daily living, motor symptoms, quality of life, and symptoms of depression.

A randomized, double-blind, placebo-controlled trial of safinamide as add-on therapy in early Parkinson's disease patients.

Safinamide is an α-aminoamide with both dopaminergic and nondopaminergic mechanisms of action evaluated as an add-on to dopamine agonist (DA) therapy in early-stage PD. In this 24-week, double-blind study, patients with early PD receiving a stable dose of a single DA were randomized to once-daily safinamide 100 mg, safinamide 200 mg, or placebo. The primary efficacy variable was UPDRS part III (motor examination) total score. Analysis was hierarchical: 200 mg of safinamide versus placebo was tested first; the success of safinamide 100 mg versus placebo was contingent on this. Two hundred sixty-nine patients received safinamide 100 mg (n = 90), safinamide 200 mg (n = 89), or placebo (n = 90); 70, 81, and 81 patients, respectively, completed the study. Mean improvements from baseline to week 24 in UPDRS III total scores were -3.90 for safinamide 200 mg, -6.0 for safinamide 100 mg and -3.60 for placebo. The difference between safinamide 200 mg and placebo was not significant [point estimate: -0.4; 95% confidence interval (CI): -2.3-1.4; P = 0.6504]. Although the difference between 100 mg/day and placebo was significant (point estimate: -1.9; 95% CI: -3.7 to -0.1; P = 0.0419), these results are considered exploratory. No clinically meaningful differences from placebo were observed for any safety variables. This study did not demonstrate a significant improvement of the primary endpoint for safinamide 200 mg/day. Exploratory analysis of the primary endpoint for 100 mg/day demonstrated that the addition of safinamide to a stable dose of DA improves motor symptoms in early PD and warrants further investigation.