Efficacy and Safety of a Once-daily Extended-release Formulation of Pramipexole Switched from an Immediate-release Formulation in Patients with Advanced Parkinson’s Disease: Results from an Open-label Study

Abstract

This study aimed to evaluate the efficacy and safety of an extended-release tablet formulation of pramipexole (PPX-ER) given once daily when switched from an immediate-release tablet formulation (PPX-IR) given 3 times daily. This open-label study included 29 patients with idiopathic Parkinson's disease (PD) who were followed for 8 weeks. Primary endpoints were Unified Parkinson's Disease Rating Scale (UPDRS) part III score, a physician evaluation of motor symptoms; nocturnal and early morning symptoms (NEMS) score, based on the results for 4 items in the Parkinson's Disease Sleep Scale and the Movement Disorder Society - sponsored revision of the UPDRS; and patients' formulation preference, determined through questionnaires. Secondary endpoints were nocturnal sleep disturbance, evaluated using the revised version of the Parkinson's Disease Sleep Scale (PDSS-2); quality of life, evaluated using the 39-item Parkinson's Disease Questionnaire (PDQ-39); Clinical Global Impression-Improvement (CGI-I) score; Patient Global Impression-Improvement (PGI-I) score; and caregiver formulation preference. UPDRS part III score (mean ± SD) was significantly decreased after 4 weeks (13.9 ± 7.3; P=0.030) and 8 weeks (12.2 ± 7.3; P<0.001) from baseline (15.3 ± 7.0). However, no significant change was found in NEMS scale, PDSS-2 or PDQ-39 scores. After 8 weeks, the responder rates based on CGI-I and PGI-I scores were 27.6% and 20.7%, respectively. As a result of the questionnaire, 63.0% of patients and 58.8% of their caregivers preferred PPX-ER. A non-serious drug-related adverse event (diarrhea) was observed in one patient. In conclusion, PPX-ER can be considered as a useful treatment option when PPX-IR needs to be switched to other dopamine agonists.This study is registered with UMIN-CTR (UMIN000006521).