Study of KW-6002 (Istradefylline) for the Treatment of Parkinson's Disease in Patients Taking Levodopa

Study Overview
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Brief Summary
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The purpose of this study is to establish the efficacy of 20 mg/day and 40 mg/day doses of istradefylline for reducing the mean total hours of awake time per day spent in the OFF state in patients with advanced Parkinson's disease (PD) treated with levodopa. Patients who meet entry criteria will be randomized in a 1:1:1 ratio to double blind treatment with oral doses of 20 or 40 mg/day istradefylline or matching placebo. Patients will be treated for 12 weeks and will have interim visits and end of treatment visit to assess the efficacy and safety of istradefylline.

Official Title
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Placebo-Controlled, Double-Blind, Parallel Group, Fixed Dose Study of KW-6002 (Istradefylline) in the Treatment of Parkinson's Disease (Phase 3)

Conditions
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Parkinson's Disease

Intervention / Treatment
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* Drug: Istradefylline
* Drug: Istradefylline
* Drug: Placebo


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Be willing and able to give written informed consent UK Parkinson's Disease Society (UKPDS) brain bank criteria (Step 1 and 2) for PD PD stages 2-4 in the OFF state for Modified Hoehn and Yahr Scale On levodopa/dopa-decarboxylase inhibitor for at least one year Taking at least three doses and >=300 mg of levodopa/dopa-decarboxylase inhibitor per day for at least four weeks before randomization Predictable end of dose wearing off Able to satisfactorily complete Hauser based 24-hour patient Parkinson's diary Have an average of two hours of OFF time on 24-hour diaries On a stable regimen of any other anti-Parkinson's drugs for at least four weeks before randomization On a stable dose of domperidone for at least 14 days before randomization Exclusion Criteria: Taking any excluded medications Neurosurgical treatment or Transcranial Magnetic Stimulation for PD Diagnosis of cancer within 5 years Diagnosis of clinically significant illness of any organ system Diagnosis of dementia or mini-mental status examination score of 23 or less History of drug or alcohol abuse or dependence within the past two years History of psychosis History of significant drug allergies Taking anticonvulsants for seizures History of neuroleptic malignant syndrome Pregnant or lactating females

Ages Eligible for Study
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Minimum Age: 20 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Double


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Istradefylline 20mg<br> | Drug: Istradefylline<br>* 20 mg KW-6002 per day (two 10 mg tablets orally once daily for 12 weeks)<br>* Other names: KW-6002;|
| Experimental: Istradefylline 40mg<br> | Drug: Istradefylline<br>* 40mg KW-6002 per day (two 20 mg tablets orally once daily for 12 weeks)<br>* Other names: KW-6002;|
| Placebo Comparator: Placebo<br> | Drug: Placebo<br>* Two placebo tablets once daily for 12 weeks<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Reducing the mean total hours of awake time per day spent in the OFF state |  |  | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Reducing the mean percentage of awake time per day spent in the OFF state |  |  | 
| Mean change in the total hours and the percentage of awake time per day spent in the ON state (without dyskinesia, with dyskinesia, with non-troublesome dyskinesia, and with troublesome dyskinesia) |  |  | 
| Change in Unified Parkinson's Disease Rating Scale (UPDRS) |  |  | 
| Change in the Clinical Global Impression - Improvement scale (CGI-I) |  |  | 
| Adverse events |  |  | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Parkinson's disease, levodopa, end of dose wearing off, OFF time