Objectives: The aim of this open-label study was to investigate the long-term safety and efficacy of selegiline as monotherapy in Japanese patients with early Parkinson disease (PD).
Methods: We conducted a 56-week prospective study in patients with early PD (N = 134) who had previously completed the randomized, double-blind, placebo-controlled phase III trial of selegiline monotherapy for 12 weeks. In the present study, dosing was titrated from 2.5 to 10 mg/d in increments of 2.5 mg/d for 2 weeks. From the seventh week, the dosage was maintained at 10 mg/d until week 56. The primary outcome was any change in the total Unified Parkinson's Disease Rating Scale (UPDRS) score (part I + II + III) from baseline. Secondary outcomes, including changes in the UPDRS subscores and safety profile, were also evaluated.
Results: Ninety-one (67.9%) patients completed the 56-week study. Treatment with selegiline significantly reduced total UPDRS score from week 4 (mean ± SD, -2.62 ± 3.83; P < 0.0001) to week 56 (-3.39 ± 9.27; P < 0.01). The peak effect was seen at week 20 (-5.79 ± 5.57; P < 0.0001). In addition, we found similar improvements in the UPDRS parts II and III scores. The incidence rate of adverse drug reactions was 44.3% (58 patients) and did not increase during the period of 10 mg selegiline administration.
Conclusions: Long-term monotherapy with selegiline (10 mg/d) was effective and well tolerated in patients with early PD in this 56-week study.