Jong-Min Kim

Background Increasing levodopa (L‐dopa)/dopa decarboxylase inhibitor (DDCI) daily dose or adding a catechol‐O‐methyltransferase (COMT) inhibitor to levodopa/DDCI therapy are strategies used to manage wearing‐off symptoms in Parkinson's disease (PD) patients. Objectives To evaluate the COMT inhibitor opicapone versus an additional dose of levodopa to treat early wearing‐off in PD patients. Methods ADOPTION was a randomized, parallel‐group, open‐label, Phase 4 study conducted in Korea. At baseline, eligible patients were randomized (1:1) to opicapone 50 mg (n = 87) or L‐dopa 100 mg (n = 81) (added to current L‐dopa/DDCI therapy) for 4 weeks. The main efficacy endpoint was change from baseline to end of study in absolute off time. Other endpoints included changes in on time, in Movement Disorder Society‐Unified Parkinson's Disease Rating Scale and 8‐item PD Questionnaire scores, and the Clinical and Patient Global Impression of Improvement/Change. Results The adjusted mean in absolute off time was significantly greater for opicapone 50 mg than for L‐dopa 100 mg (−62.1 vs. −16.7 minutes; P = 0.0015). Opicapone‐treated patients also reported a greater reduction in the percentage of off time ( P = 0.0015), a greater increase in absolute on time ( P = 0.0338) and a greater increase in the percentage of on time ( P = 0.0015). There were no significant differences in other secondary endpoints. The L‐dopa equivalent daily dose was significantly higher in the opicapone group (750.9 vs. 690.0 mg; P = 0.0247), when a 0.5 conversion factor is applied. Conclusions Opicapone 50 mg was more effective than an additional 100 mg L‐dopa dose at decreasing off time in patients with PD and early wearing‐off.