Sumanirole versus placebo or ropinirole for the adjunctive treatment of patients with advanced Parkinson's disease

The aims of this study were to assess the safety, tolerability, and efficacy of sumanirole, a highly selective D-2 dopamine receptor agonist, versus placebo in subjects with advanced Parkinson's disease (PD), and to demonstrate noninferiority of sumanirole to ropinirole. In this flexible-dose, randomized, double-blind, double-dummy, parallel-group study, 948 subjects were treated with sumanirole 1 to 48 mg/day, ropinirole 0.75 to 24 mg/day, or placebo. Treatment consisted of 13 weeks of dose escalation, 26 weeks of maintenance, and 1 week of tapering. Approximately 70% of subjects treated with either sumanirole or ropinirole completed the study. Statistical significance (P < 0.0001) was achieved when both sumanirole and ropinirole groups were compared with placebo, with mean differences of -7.7 and -8.8 on combined sum of the Unified Parkinson's Disease Rating Scale (UPDRS) part II (average on and off) and part III total scores at the end of maintenance. Noninferiority of sumanirole to ropinirole was also demonstrated, with a sumanirole minus ropinirole difference of 1.17 (90% CI: -0.56 to 2.89). Both dopamine agonists, sumanirole and ropinirole, were statistically superior compared with placebo as adjunctive therapy for patients with advanced Parkinson's disease, based on UPDRS II + III total score. Noninferiority of sumanirole to ropinirole was established, with comparable tolerability profiles. (c) 2006 Movement Disorder Society.