Efficacy and safety of adjunctive rasagiline in Japanese Parkinson's disease patients with wearing-off phenomena: A phase 2/3, randomized, double-blind, placebo-controlled, multicenter study

Introduction: Rasagiline, a selective, irreversible monoamine oxidase-B inhibitor, is in development in Japan as adjunctive therapy to levodopa. This Phase 2/3 trial evaluated the efficacy and safety of adjunctive rasagiline in Japanese patients with Parkinson's disease (PD) and wearing-off phenomena. Methods: Patients aged 30-79 years with diagnosed PD and stable levodopa use were randomized 1:1:1 to rasagiline (0.5/1 mg/day) or placebo for 26 weeks. The primary endpoint was change from baseline in mean daily OFF-time during the treatment period. Results: In total, 141, 134, and 129 patients were randomized to placebo, rasagiline 0.5 mg, or rasagiline 1 mg, respectively. Baseline characteristics were well balanced. Least squares (LS) mean differences vs. placebo for change from baseline in mean daily OFF-time were -0.84 h (rasagiline 1 mg/day) and 0.60 h (rasagiline 0.5 mg/day); both differences were statistically significant. LS mean differences vs. placebo for change from baseline in Movement Disorder Society-Unified Parkinson's Disease Rating Scale (MDS-UPDRS) Part II and Part III total scores (in ON-state) and Parkinson's Disease Questionnaire-39 Summary Index Score were: -1.27, -1.74, and -2.51 (0.5 mg/day) and -1.27, -2.14, and -3.84 (1 mg/day); all statistically significant. Treatment-emergent adverse events (TEAEs) occurred in 50.4/69.9/73.6% of the placebo, 0.5 mg/day, and 1 mg/day groups, respectively (most common TEAEs were nasopharyngitis [9.2/18.0/14.7%] and dyskinesia [7.1/8.3/16.3%]). Conclusions: As an adjunct to levodopa, rasagiline reduced OFF-time and improved PD symptoms/signs (MDS-UPDRS scores) and quality of life in Japanese patients with PD and wearing-off phenomena. No important safety concerns were raised.