The purpose of this study is to evaluate the safety, tolerability and efficacy of eltoprazine to treat levodopa-induced dyskinesia in patients with Parkinson's disease

A double-blind, placebo-controlled, crossover, dose-range finding study in patients with Parkinson's disease and levodopa-induced dyskinesia. The study will examine the effects of three different doses of eltoprazine HCl, compared to placebo, on severity of dyskinesia, parkinsonian symptoms, patient function, safety and tolerability, using Parkinson's disease rating scales, patient diaries and physiological measurement of abnormal movement by means of motion sensors.

Inclusion Criteria:

• outpatient with idiopathic PD
• stable dose of anti-parkinsonian medication for at least four weeks before the Screening Visit
• daily levodopa dose ≥300 mg per day divided into at least three doses
• treated with levodopa for at least three years prior to study entry
• moderate to severely disabling levodopa-induced dyskinesia for at least three months prior to study entry
• dyskinesia for, on average, >25% of the waking day

Exclusion Criteria:

• inability to use the motion sensors or electronic diaries correctly
• surgical treatment for PD, e.g. Deep Brain Stimulation, within the last six months or planned during the study
• unstable co-existing psychiatric disease including psychosis, depression or cognitive impairment
• Mini Mental State Examination score of <24
• moderate or severe renal, or severe hepatic, impairment
• treatment with selective serotonin re-uptake inhibitors (SSRI) or any combined serotonin-norepinephrine re-uptake inhibitors (SNRI), such as tryptizol, citalopram, escitalopram, sertraline, mianserin, mirtazapin, paroxetin, venlafaxine and St John's Wort, within four weeks prior to the Screening Visit
• treatment with medications with the potential for drug-interactions (MAO-A inhibitors, apomorphine, aripiprazol, carbamazepine, clozapine, phenytoin, tramadol, quetiapine, varfaine, valproic acid). Patients taking amantadine will comprise no more than 25% of the study population
• current history of a clinically significant and uncontrolled medical condition that may affect the safety of the patient or preclude adequate participation in the study
• pregnant or breast-feeding
• received any other investigational medicinal product within 30 days of Screening