Effects of Gocovri (Amantadine) Extended-Release Capsules on Motor Aspects of Experiences of Daily Living in People with Parkinson's Disease and Dyskinesia

Introduction Gocovri, a bedtime-administered delayed-release/extended-release capsule formulation of amantadine, is the only drug approved by the US Food and Drug Administration as levodopa-adjunctive therapy for the treatment of OFF episodes and/or dyskinesia in Parkinson's disease (PD). Part II of the Movement Disorder Society Unified Parkinson's Disease Rating Scale (MDS-UPDRS) assesses patient-perceived disability on experiences of daily living affected by PD motor symptoms. We analyzed Gocovri-related changes in MDS-UPDRS Part II ratings in two placebo-controlled clinical trials. Methods Baseline to week 12 changes in MDS-UPDRS Part II total and item scores were compared for Gocovri and placebo using pooled data from phase 3 trials (EASE LID and EASE LID 3). Results Baseline mean MDS-UPDRS Part II total score was 15.1 for Gocovri (n = 100) and 15.3 for placebo (n = 96) groups. At week 12, the least squares mean change from baseline was -3.4 for the Gocovri group and -1.4 for placebo (treatment difference, -2.0; 95% CI -3.3 to -0.7; P = 0.004). For Gocovri, change from baseline exceeded a published minimal clinically important difference threshold of 3.05. Gocovri-related treatment differences over placebo were driven primarily by improvement in the scale items of freezing (-0.4; P < 0.0001), tremor (-0.4; P = 0.002), getting out of bed/car/deep chair (-0.3; P = 0.002), and eating tasks (-0.2; P = 0.016). Conclusion In addition to improvement in dyskinesia, Gocovri-treated participants experienced improvement in motor aspects of experiences of daily living. Analyses suggest that Gocovri may specifically improve freezing, tremor, getting out of bed/car/deep chair, and eating tasks.