BackgroundRasagiline is a monoamine oxidase-B inhibitor used for Parkinson's disease (PD) treatment, but its effectiveness on Chinese patients is unclear. This study aimed to evaluate the efficacy and safety of rasagiline monotherapy in Chinese patients with early PD.MethodsA 26-weeks, randomized, double-blind, placebo-controlled study has been performed at 15 sites in China and enrolled outpatients (35years old) with idiopathic PD without a history of using any dopaminergic drugs. Participants were randomized 1:1 to receive rasagiline 1mg once daily or placebo. The primary endpoint was the change of the Unified Parkinson's Disease Rating Scale (UPDRS) total score from baseline to 26weeks treatment. Secondary endpoints included changes in UPDRS subscale scores from part I to III. Health status was assessed with the PD Questionnaire (PDQ)-39 and EuroQol-Five-Dimension (EQ-5D) questionnaire. Safety profile was collected until 30weeks after randomization.ResultsA total of 130 patients (n=65/group) were recruited, and 127 (rasagiline, n=64; placebo, n=63) were included in the full analysis set. Baseline characteristics were comparable between the two groups. The decrease in the mean UPDRS total score was greater in the rasagiline group than in the placebo group (-3.180.95 vs. -0.180.98, P=0.025), and the mean UPDRS part I non-motor symptoms score (-0.54 +/- 0.15 vs. -0.08 +/- 0.15, P=0.003) were significantly decreased in the rasagiline group compared with placebo treated patients. An improvement trend was observed in the active treatment group for the subscales evaluation with parts II and III, while the difference to placebo was not statistically significant. Life quality assessed by the EQ-5D visual analog scale improved in the rasagiline group but worsened in placebo treated patients. The overall incidence of treatment-emergent adverse events (AEs) was slightly lower in the rasagiline group (41.5%) than in the placebo group (46.2%).Conclusions Rasagiline is effective, safe, and well tolerated as monotherapy for the treatment of Chinese PD patients.Trial registration Clinicaltrials.gov: NCT01556165. Registered 13 Mar 2012.