Real-World Use of COMT Inhibitors in the Management of Patients with Parkinson’s Disease in Spain Who Present Early Motor Fluctuations: Interim Results from the REONPARK Study

Abstract

Objective: We aimed to analyze the real-world use of COMT inhibitors associated with levodopa in patients with Parkinson’s disease (PD) who present early fluctuations and to explore whether early COMT inhibition optimizes treatment outcomes. Methods: REONPARK is an ongoing 2-year prospective observational study. We included patients diagnosed with PD who presented signs of end-of-dose motor fluctuations for <2 years and started COMT inhibitors according to clinical practice. Outcomes included the clinician and patient global impression of change (CGI-C, PGI-C), the Movement Disorder Society-sponsored revision of the Unified Parkinson’s Disease Rating Scale (MDS-UPDRS), the Parkinson’s Disease Questionnaire-8 (PDQ-8), Non-Motor Symptoms Scale (NMSS), 19-Symptom Wearing-off Questionnaire (WOQ-19), and safety. We present a pre-planned interim analysis (cut-off date 3 July 2023) of patients who completed the first 3 months of follow-up. Results: Seventy patients were analyzed (mean levodopa dose at inclusion 484.8 mg; duration of motor fluctuations 0.6 years). In all cases, COMT inhibition was initiated with opicapone, and 81% maintained a stable levodopa dose at 3 months. After 3 months of treatment with opicapone, 73.5% and 62.8% of patients improved on CGI-C and PGI-C, respectively. MDS-UPDRS scores improved significantly with a mean change from baseline of −3.3 ± 7.7 (p < 0.001) for Part III and −1.3 ± 1.7 (p < 0.001) for Part IV. The mean OFF time decreased from 3.7 ± 2.6 h at baseline to 2.2 ± 2.3 h, and 20.6% of patients no longer experienced OFF periods. Patients experiencing no impact of fluctuations increased from 10% to 45.6%. Conclusions: In PD patients with early fluctuations, three months of opicapone reduced the OFF time and improved functional outcomes, suggesting potential benefits in the early stages.