A Study of Istradefylline (KW-6002) for the Treatment of Parkinson's Disease in Patients Taking Levodopa
A Study of Istradefylline (KW-6002) for the Treatment of Parkinson's Disease in Patients Taking Levodopa
To establish the efficacy of a 20 mg/day dose of istradefylline for reducing the percentage
 of OFF time in patients with advanced Parkinson's disease (PD) treated with levodopa.
To establish the efficacy of a 20 mg/d dose of istradefylline for reducing the percentage of
 OFF time in patients with advanced Parkinson's disease (PD) treated with levodopa. Patients
 who meet entry criteria will be randomized in a 1 to 1 ratio to either 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 as compared to
 placebo.
Inclusion Criteria:

 1. UK Parkinson's Disease Society (UKPDS) brain bank criteria (Step 1 and 2) for PD.

 2. PD stages 2-4 in the OFF state for Modified Hoehn and Yahr Scale.

 3. On levodopa/carbidopa for at least one year, stable dose in past 4 weeks.

 4. Currently take at least three doses of levodopa/carbidopa per day.

 5. Predictable end of dose wearing off.

 6. Able to satisfactorily complete Hauser version of a Parkinson's diary.

 7. Have an average of 180 minutes of OFF time on two 24 hour diaries.

 8. Be at least 30 years of age.

 Exclusion Criteria:

 1. Neurosurgical treatment for PD.

 2. History of psychosis.

 3. Diagnosis of atypical parkinsonism, secondary parkinsonism variant or Parkinson's plus
 syndromes.

 4. Diagnosis of cancer within 5 years.

 5. Mini-mental status examination score of 25 or less.

 6. History of seizures or neurologic malignant_syndrome.

 7. Clinical depression.