• Parkinson's disease;
  • dopamine agonist;
  • sumanirole;
  • ropinirole


To assess the safety and efficacy of sumanirole, a highly selective dopamine agonist, versus placebo and demonstrate its noninferiority to ropinirole, 614 patients with early Parkinson's disease (PD) were treated with sumanirole, 1 to16 mg/day; ropinirole, 0.75 to 24 mg/day; or placebo. Primary end point in this flexible-dose, double-blind, double-dummy, parallel-group study of 40 weeks was the change in total sum of the United Parkinson's Disease Rating Scale (UPDRS) Parts II + III scores from baseline to end of maintenance. Approximately half the subjects in the sumanirole and placebo groups withdrew early from the study, most (51.8% and 68.5%, respectively) due to lack of efficacy. Of the ropinirole subjects who withdrew (50.5%), most discontinued because of adverse events. In sumanirole and ropinirole groups, mean changes from baseline of −2.48 and −5.20 in UPDRS II + III mean scores were significant versus 0.38 in the placebo group (P ≤ 0.006). Sumanirole and ropinirole are effective in the treatment of patients with early PD when compared with placebo. Noninferiority of sumanirole to ropinirole was not demonstrated, with a difference of 2.70 (90% CI, 0.92–4.49). Sumanirole was better tolerated than ropinirole. © 2007 Movement Disorder Society