Adenosine A2A receptor antagonist istradefylline reduces daily OFF time in Parkinson's disease

Abstract

BackgroundWe evaluated the efficacy and safety of istradefylline, a selective adenosine A2A receptor antagonist administered as adjunctive treatment to levodopa for 12 weeks in a double-blind manner in Parkinson’s disease patients with motor complications in Japan.MethodsA total of 373 subjects were randomized to receive placebo (n = 126), istradefylline 20 mg/day (n = 123), or istradefylline 40 mg/day (n = 124). The primary efficacy variable was the change in daily OFF time. Other secondary variables were also evaluated.ResultsThe change in daily OFF time was significantly reduced in the istradefylline 20 mg/day (−0.99 hours, P = .003) and istradefylline 40 mg/day (−0.96 hours, P = .003) groups compared with the placebo group (−0.23 hours). The most common adverse event was dyskinesia (placebo, 4.0%; istradefylline 20 mg/day, 13.0%; istradefylline 40 mg/day, 12.1%).ConclusionsIstradefylline reduced daily OFF time and was well tolerated in Japanese PD patients with motor complications on levodopa treatment.