A controlled, randomized, delayed-start study of rasagiline in early Parkinson disease.

BACKGROUND: Treatment with rasagiline mesylate, an irreversible monoamine oxidase type B inhibitor, improves symptoms of early Parkinson disease (PD). Preclinical studies suggest that this compound may also modify the progression of PD.

OBJECTIVE: To compare the effects of early and later initiation of rasagiline on progression of disability in patients with PD.

DESIGN: Double-blind, parallel-group, randomized, delayed-start clinical trial.

SETTINGS AND PATIENTS: Four hundred four subjects with early PD, not requiring dopaminergic therapy, enrolled at 32 sites in the United States and Canada.

INTERVENTIONS: Subjects were randomized to receive rasagiline, 1 or 2 mg/d, for 1 year or placebo for 6 months followed by rasagiline, 2 mg/d, for 6 months.

MAIN OUTCOME MEASURE: Change in total Unified Parkinson's Disease Rating Scale score from baseline to 12 months.

RESULTS: Three hundred seventy-one subjects were included in the 1-year efficacy analysis. Subjects treated with rasagiline, 2 mg/d, for 1 year had a 2.29-unit smaller increase in mean adjusted total Unified Parkinson's Disease Rating Scale score compared with subjects treated with placebo for 6 months followed by rasagiline, 2 mg/d, for 6 months (P =.01). The mean adjusted difference between the placebo/rasagiline, 2 mg/d, group and those receiving rasagiline, 1 mg/d, for 1 year was -1.82 unit on the Unified Parkinson's Disease Rating Scale score (P =.05).

CONCLUSION: Subjects treated with rasagiline, 2 and 1 mg/d, for 12 months showed less functional decline than subjects whose treatment was delayed for 6 months.