The oasis (opicapone in sleep disorder) study in Parkinson's disease: Design and rationale of an open-label, single-arm, pilot trial

ABSTRACT

Background and aims: Opicapone (OPC) proved to be effective in the treatment of end-of-dose motor fluctuations in Parkinson's disease (PD) patients. Non-motor symptoms have a substantial impact on health-related quality of life and are reported in approximately 90% of idiopathic PD patients. End-of-dose motor fluctuations and associated sleep disorders are commonly observed in PD patients who receive treatment with levodopa (L-dopa)/DOPA decarboxylase inhibitors (DDCI). This study aims to evaluate the effects of OPC treatment on sleep disorders in PD patients with ‘wearing-off’. Methods: Approximately 30 patients (aged ≥30 years) with idiopathic PD, treated with 3–8 daily doses of L-dopa/DDCI, with ‘wearing-off’ and sleep disorders will receive OPC 50 mg once daily during a 6-week evaluation period. L-dopa/DDCI daily dose, but not number of intakes, may be adjusted according to the patients' response in the first 2 weeks, and is kept unchanged afterwards (Fig. 1). As a pilot study, no formal sample size calculation was performed. [Formula presented] Results: The primary endpoint is change from baseline in total score of Parkinson's Disease Sleep Scale-2. Secondary endpoints include tolerability, functional motor and non-motor assessments (Movement Disorder Society-Non-Motor Symptoms Scale, Parkinson's Disease Questionnaire-8, Parkinson's Fatigue Scale, ON/OFF home diary), and Clinical and Patient Global Impression of Change scales. Study sites are in Germany and Portugal. First-patient-in is expected for early 2021 and last-patient-out for late 2021. Timelines might be impacted by the COVID-19 situation. Conclusions: This pilot study will provide preliminary data on the potential effect of OPC 50 mg once daily as adjunctive therapy to L-dopa/DDCI on PD-associated sleep disorders.