The efficacy and safety of pramipexole ER versus IR in Chinese patients with Parkinson’s disease: a randomized, double-blind, double-dummy, parallel-group study

Objective:To evaluate the non-inferiority of pramipexole extended-release(ER)versus immediate-release(IR)in Chinese patients with Parkinson’s disease(PD)in a double-blind,randomized,parallel-group study.Methods:Subjects were Chinese patients with idiopathic PD with diagnosis≥2 years prior to trial,age≥30 years old at diagnosis,and Modified Hoehn and Yahr score 2-4 during‘on’-time.Subjects received treatment with pramipexole ER(n=234)or IR(n=239).Non-inferiority was based on the primary endpoint,the change from baseline to end of maintenance(week 18)in the UPDRS(Parts II+III)total score.Results:For the primary endpoint,the adjusted mean changes(standard error)of UPDRS Parts II+III at week 18 were−13.81(0.655)and−13.05(0.643)for ER and IR formulations,respectively,using ANCOVA adjusted for treatment and centre(fixed effect)and baseline(covariate).The adjusted mean between group difference was 0.8 for the 2-sided 95%CI(−1.047,2.566).Since the lower limit of the 2-sided 95%CI(−1.047)for treatment difference was higher than the non-inferiority margin of−4,non-inferiority between pramipexole ER and IR was demonstrated.The incidence of adverse events(AEs)was 68.8%in the ER arm and 73.6%in the IR arm with few severe AEs(ER:2.1%;IR:3.8%).Conclusion:Based on the UPDRS II+III score,pramipexole ER was non-inferior to pramipexole IR.The safety profiles of pramipexole ER and IR were similar.These results were based on comparable mean daily doses and durations of treatment for both formulations.