Long-term real-world effectiveness of carbidopa/levodopa enteral suspension after 36 months of treatment initiation in advanced Parkinson's disease in the US: final results from the PROviDE study.

Introduction: Clinical trials and observational studies have demonstrated that carbidopa/levodopa enteral suspension (CLES) significantly improves advanced Parkinson's disease (aPD) symptoms. This study examined the real-world, long-term impact of CLES on patient-reported outcomes (PROs) in people with aPD. Methods: Pursuing Real-World Outcomes via Duopa Ecosystem (PROviDE) was a 36-month prospective, observational study evaluating the effectiveness of CLES in patients with aPD in the US. PROs were collected at baseline, 3 months, and every 6 months after CLES initiation and included OFF-time, Treatment Satisfaction Questionnaire for Medication-9 (TSQM-9), and Parkinson's Disease Questionnaire-8 (PDQ-8) assessing PD-related quality of life (QoL). Longitudinal treatment effects were evaluated using mixed-effect models. Results: Of 104 patients, 47 (45.2%) provided 36 months of data and were evaluated in the final mixed-model analysis. Patients mean standard deviation (SD) age was 67.0 (8.7) years with a mean (SD) PD diagnosis of 11.0 (6.2) years. Compared with baseline, CLES resulted in statistically significant and clinically meaningful improvements in hours of OFF-time as early as month 3 (mean: -2.7 h/day, p < .0001) and sustained at month 36 (-1.7 h/day, p = .004). Improvements were also observed in treatment effectiveness (≥19 points, all p < .0001), global satisfaction with treatment and convenience of therapy (≥10 points each; all p < .001) over 36 months. A statistically significant improvement in PDQ-8 was observed as early as month 3 (-4.1, p = .001) with no worsening over time. Conclusion: Long-term treatment with CLES provides significant and clinically meaningful reduction in OFF-time, patient's treatment satisfaction, and maintained QoL in the real-world setting.