Levodopa-Carbidopa Intestinal Gel Improves Dyskinesia in Parkinson's Disease: Post Hoc Analysis from the COSMOS Study

Dyskinesia is a debilitating complication of dopaminergic therapy in advanced Parkinson's disease.

To evaluate the effect of levodopa-carbidopa intestinal gel (LCIG) on dyskinesia burden.

This is a post hoc analysis of the retrospective, observational COmedication Study assessing Mono- and cOmbination therapy with levodopa-carbidopa inteStinal gel (COSMOS; NCT03362879). Change in dyskinesia was assessed by LCIG treatment group (monotherapy, daytime monotherapy, polytherapy), baseline dyskinesia duration (<4 vs. ≥4 hours), and dyskinesia severity (troublesome vs. non-troublesome). Correlations between changes in dyskinesia and patient-reported outcomes (Parkinson's Disease Questionnaire-8 [PDQ-8], Parkinson's Disease Sleep Scale-2 [PDSS-2], non-motor symptoms scale [NMSS]) were assessed using Spearman correlation coefficients. The Unified Parkinson's Disease Rating Scale IV measured dyskinesia duration (Item 32), severity (Item 33), and pain (Item 34). Data were collected cross-sectionally at a single study visit.

Over 50% (202/369) of LCIG-treated patients experienced improvement in dyskinesia severity. Improvements in dyskinesia duration and severity were noted in all treatment groups. The proportion of patients with troublesome dyskinesia and amount of "Off" time significantly decreased from baseline to study visit, regardless of baseline dyskinesia burden (P < 0.01); dyskinesia duration improved only in the ≥4-hour subgroup (P < 0.01). In the ≥4-hour subgroup, dyskinesia duration correlated positively with PDQ-8; dyskinesia severity correlated positively with PDQ-8 and PDSS-2; and dyskinesia pain correlated positively with PDQ-8, PDSS-2, and NMSS.

LCIG led to reductions in dyskinesia severity, regardless of baseline dyskinesia burden. Dyskinesia duration improved in patients with high dyskinesia burden but not in those with low dyskinesia burden.