To examine the long-term impact of carbidopa/levodopa enteral suspension (CLES) on quality of life (QoL) in patients with advanced Parkinson’s disease (APD) in the real world.

APD patients have severe motor and non-motor symptoms which remarkably decrease their QoL as the disease progresses. Clinical trials and observational studies have shown that CLES can significantly improve the APD symptoms.

This is an interim analysis at 24 months from the ongoing PROviDE study. Self-reported off-time was normalized to 16-hour waking day. QoL and treatment satisfaction were measuring using validated instruments (PDQ-8 and TSQM-9, respectively). Longitudinal treatment effect was evaluated across 3, 6, 12, 18, and 24 months based on a mixed model controlling for age, gender, ability to walk, number of years since PD, and previous DBS treatment. Published literature was used to define the threshold for clinically meaningful improvement in QoL (? ≥ 5.8 points).

At baseline, the study sample (n=38 patients) was comparable to clinical trials (normalized off-time: 6.2±2.2 hours, PDQ-8: 43.4±19.6). At 3, 6, 12, 18, 24 months after initiation of CLES, patients were observed to have significant reduction in off-time/day, comparable to the effect seen in clinical trials (? = -3.2, -3.4, -3.7, -3.8, - 3.5 hours/day (p-value<0.0001)) respectively. Significant and clinically meaningful improvement in QoL was also observed at 3, 6, 12, 18, 24 months (? = -8.0, -6.7, -7.3, -9.7, -5.8 (p-value<0.05)) respectively. Across all the visits up to 24 months, significant improvement was also observed in the treatment satisfaction with effectiveness, convenience, and global satisfaction.

This is one of the first US-specific long-term evaluations of CLES in real-world settings. Sustained treatment effect was observed to be comparable to clinical trials and clinically meaningful over 24 months. This evidence suggests that CLES has sustained long-term effects in controlling motor fluctuations and improving patient’s QoL.