Opicapone OASIS study in Parkinson's: Design of an open-label, single-arm, pilot trial

Background and aims: Opicapone proved to be effective in the treatment of end-of-dose motor fluctuations in Parkinson's Disease (PD) patients [1,2]. Non-motor symptoms have a substantial impact on health-related quality-of-life and are reported in about 90% of idiopathic PD patients [3]. End-of-dose motor fluctuations and associated sleep disorders are commonly observed in PD patients under treatment with L-dopa/DOPA decarboxylase inhibitors (DDCI). Therefore, there is the expectation that opicapone might improve such symptoms. Methods: Approximately 30 patients (aged 30 years) with idiopathic PD, treated with 3-8 daily oral doses of L-dopa/ DDCI, with 'wearing-off' and experiencing sleep disorders will receive OPC 50mg once-daily during a 6-week evaluationperiod. L-dopa/DDCI daily dose, but not number of intakes, may be adjusted according to subject response in the first 2 weeks, and kept unchanged afterwards (Figure 1). As a pilot study, no formal sample size calculation was performed. Results: The primary endpoint is change from baseline in total score of Parkinson's Disease Sleep Scale (PDSS-2). Secondary endpoints include tolerability, functional motor and non-motor assessments [MDS-NMS, PDQ-8, Fatigue Scale (PFS-16), ON/OFF home diary] and Global Impression of Change (CGI-C, PGI-C). Study sites are in Germany and Portugal. First-patient-in is expected for 2021 and Last-patient-out to late 2021. Timelines might be impacted by COVID-19 pandemic situation. Conclusion: This study will further evaluate the potential impact of OPC 50mg once-daily as adjunctive therapy to L-dopa/DDCI on PD-associated sleep disorders. (Figure Presented).