Real-World Use of Opicapone in Management of Patients with Parkinson’s Disease and Early Motor Fluctuations in Spain: 12-Month Interim Analysis of REONPARK Study

Objective: To evaluate the sustained real-world effectiveness and safety of catechol-O-methyltransferase (COMT) inhibitors added to levodopa in patients with Parkinson’s disease (PD) presenting early motor fluctuations. Methods: REONPARK is an ongoing, multicenter, prospective observational study conducted in Spain. Adult patients with PD and end-of-dose motor fluctuations for <2 years initiating a COMT inhibitor were included. Outcomes assessed at 3, 6, and 12 months included Clinician and Patient Global Impression of Change (CGI-C, PGI-C), Movement Disorder Society–Unified Parkinson’s Disease Rating Scale (MDS-UPDRS), Wearing-off Questionnaire (WOQ-19), Non-Motor Symptoms Scale (NMSS), Parkinson’s Disease Questionnaire-8 (PDQ-8), and safety. This article presents the 3-, 6-, and 12-month planned interim analysis of the study. Results: A total of 143 patients were included (99.3% treated with opicapone), of whom 138, 131, and 89 patients completed the 3, 6, and 12 months of follow-up, respectively. Levodopa doses remained stable in most patients (73% at 12 months). Significant and sustained improvements were observed in MDS-UPDRS Parts III and IV scores, as well as the total MDS-UPDRS score over 12 months, with greater likelihood of Part IV improvement in patients receiving <4.5 mg/kg/day of levodopa. OFF time decreased by 1.6–2.0 h from baseline. ON-time quality was maintained over time with 97.7% of patients reporting no or minimal functional impact from dyskinesia, while 47.7% of patients had no impact from motor fluctuations and 36.4% of patients no longer experienced OFF periods at 12 months. PDQ-8 scores remained stable and no overall benefit on total non-motor symptoms burden was demonstrated, despite improvements in selected domains among patients with a higher baseline non-motor symptoms burden. WOQ-19 scores improved significantly. Conclusions: In PD patients with early motor fluctuations, opicapone initiation was associated with sustained improvements in motor outcomes and reduced OFF time, and maintained the ON-time quality over 12 months, with stable levodopa dosing.