Parkinson's disease is a progressive disease which results in deterioration of motor function and is the result of dopamine depletion in specific brain structures. Current therapeutic approaches include dopamine replacement and the use of dopamine receptor agonist drugs. These therapies are effective but may be associated with unwanted complications like wearing off phenomena and involuntary abnormal movements (dyskinesia). Istradefylline may provide a nondopaminergic approach to the treatment of Parkinson's disease.~This study will compare the efficacy of 40 mg per day of istradefylline in improving the symptoms of Parkinson's disease with placebo.
The primary purpose of this study is to evaluate the efficacy, safety, and tolerability of 40 mg per day of istradefylline (KW6002) as monotherapy in patients with Parkinson's disease.