Introduction: Patients with Parkinson's disease (PD) experience various motor and non-motor symptoms. We conducted a post hoc analysis of a Japanese phase 2/3 study of safinamide (50 or 100 mg/day) in patients with Parkinson's disease and wearing-off to evaluate response according to background factors. Safinamide efficacy against major motor symptoms was also assessed.
Methods: Multiple regression analyses in safinamide-treated patients (50 or 100 mg/day) assessed changes in daily ON-time without troublesome dyskinesia (hereafter referred to as ON-time) according to baseline clinical variables. Subgroup analyses by baseline Unified Parkinson's Disease Rating Scale (UPDRS) part III score were also conducted. We evaluated cardinal motor symptoms using the UPDRS.
Results: In the multiple regression analysis, changes in ON-time were related to baseline non-motor symptoms (UPDRS part I score) and ON-time in the 50-mg group, but no relationships with non-motor symptoms were observed in the 100-mg group. Additionally, in the subgroup analysis of patients with more severe motor symptoms (UPDRS part III score > 20), a significant improvement in ON-time was observed only with 100 mg/day (p = 0.01). At both doses, safinamide significantly improved cardinal motor symptom scores (bradykinesia, rigidity, tremor, axial symptoms, and gait disturbances).
Conclusions: The observed response profile to the 50-mg/day dose may be related to baseline non-motor symptoms, but this was not true for the 100-mg/day dose. Both safinamide doses improved major motor symptoms in levodopa-treated patients with PD.
Keywords: Clinical trial; MAO-B inhibitor; Motor symptom; Parkinson's disease; Post hoc analysis; Safinamide.
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