Opicapone for Parkinson's disease-related sleep disturbances: The OASIS clinical trial

Background While sleep disturbances are among the most frequent non-motor symptoms of Parkinson's disease (PD), there is a lack of evidence to support its treatment. Objective To evaluate the efficacy of opicapone 50 mg in treating sleep disturbances in patients with PD and end-of-dose motor fluctuations. Methods OASIS was an exploratory, open-label, single-arm clinical trial in PD patients with end-of-dose motor fluctuations and associated sleep disturbances. The primary endpoint was change from baseline to week 6 in Parkinson's Disease Sleep Scale 2 (PDSS-2). Secondary endpoints included functional motor and non-motor assessments (Movement Disorder Society [MDS]-Unified Parkinson's Disease Rating Scale [UPDRS], MDS-Non-motor Scale [NMS], 8-item PD Questionnaire [PDQ-8], 16-item PD Fatigue Scale [PFS-16], ON/OFF home diary), Clinical and Patient Global Impression of Change (CGI-C; PGI-C) and adverse events. Results At week 6, there was a significant reduction of −7.9 points (95%CI −13.6, −2.2; p = 0.0099) in PDSS-2 total score, with a significant mean change of −4.7 in the PDSS-2 domain of disturbed sleep (95%CI: −7.2, −2.3; p = 0.0009). Significant reductions were also observed in PFS-16 (−9.6; p = 0.0211), MDS-NMS total score (−28.9; p = 0.0015), MDS-UPDRS-III (−6.3; p = 0.0253), MDS-UPDRS-IV (−1.2; p = 0.0044) and PDQ-8 (−14.2; p = 0.0051). Absolute OFF-time was reduced (−142.1 min). Most patients (93.3%) and most clinicians (80.0%) reported improvements on PGI-C and CGI-C, respectively. Opicapone was well tolerated. Conclusions Adding opicapone 50 mg to levodopa/DDCI therapy in patients with PD and motor fluctuations and sleep disturbances improved both sleep disturbances and OFF time in these patients.