Increasing the time to onset of dyskinesia
** This study is active but closed to open recruitment **
A two-year Phase IIIb randomized, multicenter, double-blind levodopa-controlled, parallel group, flexible dose study, to assess the effectiveness of an investigational agent as add-on therapy to levodopa at increasing the time to onset of dyskinesia in Parkinson's disease subjects.
The Parkinson's Disease and Movement Disorders Center is participating in this multicenter clinical trial sponsored by GlaxoSmithKline. Approximately 350 subjects will be enrolled at 75 sites in North America. The primary objective of the study is to evaluate the time to onset of dyskinesia (drug-induced involuntary movements) over two years of treatment with an investigational agent compared with levodopa alone in patients who are already being treated with levodopa with suboptimal benefit.
Design of the study: Patients will be randomized to either treatment with add-on investigational agent or levodopa in a blinded fashion. Neither subjects nor investigators will be aware of treatment assignment. Subjects will have a 50% chance of receiving active treatment with the investigational agent. The primary end-point of the study will be time to onset of dyskinesia. There will be multiple other measures of Parkinson's disease functioning, fatigue, psychological symptoms and also quality of life at study visits. Subjects will be seen for a screening visit and, if they are judged to be appropriate for the study, a baseline visit wilt take place within once week. At that time subjects will be assigned to either active treatment with the investigational agent or levodopa. The dose of study medication will be increased according to a predetermined schedule until an optimal therapeutic response is achieved. At each study visit there will be multiple measures of safety including vital signs, laboratory tests, EKG and assessment of adverse events.
Cost to subjects: None. Participation in this study is voluntary and the study participants will not be charged for the study drug or any aspects of the research study.
Inclusion criteria: (1) Age between 30-70 years; (2) diagnosis of idiopathic Parkinson's disease; (3) treatment with 600 mg or less of levodlopa for three years or less; (4) stable dose of levodopa for at least four weeks prior to screening; (5) suboptimal response to levodopa.
Exclusion criteria: (1)A history or the presence of dyskinesia (involuntary movements); (2) History of significant psychiatric or medical illness within three months of starting the study; (3) history of dizziness or fainting due to postural hypotension; (4) dementia; (5) history of alcohol or drug abuse; (6) treatment with MAO-B inhibitor, sclegiline, within three weeks of study visit; (7) treatment with a doparnine agonist for Parkinson 's disease in the past 6 weeks; (8) pregnancy.
