Efficacy and safety of extended-release carbidopa-levodopa (IPX203) versus immediate-release carbidopa-levodopa for Parkinson's disease: A systematic review.

ObjectiveIPX203 is a newly approved oral carbidopa-levodopa formulation designed to prolong the therapeutic effect and reduce complications associated with the standard immediate-release formulation. Immediate-release carbidopa-levodopa remains the current standard of care but has a short duration of action. This study aimed to evaluate the efficacy and safety of IPX203 compared with immediate-release carbidopa-levodopa in patients with advanced Parkinson's disease.MethodsThis systematic review followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines and was registered in the International Prospective Register of Systematic Reviews (registration number: CRD42024623230). A comprehensive search of PubMed/MEDLINE, Cochrane Central Register of Controlled Trials, Web of Science, ScienceDirect, Scopus, and Embase identified randomized controlled trials comparing IPX203 with immediate-release carbidopa-levodopa. The primary outcomes were changes from baseline in "Good On-time" (periods of effective symptom control with minimal dyskinesia) and "Off-time" (periods when medication effects wear off and symptoms return). Secondary outcomes included scores on Part III of the Movement Disorder Society-Unified Parkinson's Disease Rating Scale and adverse events.ResultsA total of 466 records were screened, resulting in the inclusion of three randomized controlled trials involving 560 participants. Compared with immediate-release carbidopa-levodopa, IPX203 increased total "Good On-time" and reduced "Off-time." Scores on Part III of the Movement Disorder Society-Unified Parkinson's Disease Rating Scale demonstrated greater improvement in motor function with IPX203. The incidence of adverse events was comparable between the two groups, although treatment-emergent adverse events and treatment discontinuations were more frequent in the IPX203 group.ConclusionCompared with immediate-release carbidopa-levodopa, IPX203 increased "Good On-time," reduced "Off-time," improved motor function as measured by Part III of the Movement Disorder Society-Unified Parkinson's Disease Rating Scale, and demonstrated a comparable safety profile.