Moderate to Advanced Parkinson's Disease

Research Study Title: A Phase 3, 12-week, Double-Blind, Placebo-Controlled, Randomized, Multicenter Study to Evaluate the Efficacy of Oral Istradefylline 20 and 40 mg/day as Treatment for Subjects with Moderate to Severe Parkinson’s Disease

Funded by: Kyowa Pharmaceutical, Inc.

Clinical Trial Investigator Name: Cindy Zadikoff, MD

Clinical Trial Description:

This is a Phase 3, 12-week, double-blind, placebo-controlled, randomized, multicenter research study to evaluate the efficacy and safety of istradefylline 20 and 40 mg/d compared to placebo in patients with moderate to severe PD with motor fluctuations and dyskinesia on levodopa/carbidopa therapy.

The primary objective of the study is to establish the efficacy of istradefylline 20 and 40 milligram/day (mg/d) for reducing the total hours per day of OFF time in patients with moderate to severe Parkinson’s Disease (PD) with motor fluctuations and dyskinesia on levodopa/carbidopa therapy.

Clinical Trial Eligibility Criteria:

Research Study Visits: 7 Clinic Visits & 1 telephone follow-up (12 wks)

Treatment:  Istradefylline (20 and 40 mg/d) or placebo

Compensation: $75 for each study visit.

 IRB Project #: STU00085134


For More Information: Call us at 312-503-0755, or email


Northwestern Medicine and Northwestern University Feinberg School of Medicine will not release any of your personal information to 3rd parties, participating organizations and/or other institutions. Your information will only be available to the researcher(s) after you indicate interest in being contacted about a particular study.

Newly Diagnosed

Newly diagnosed with Parkinson’s disease and not yet treated? Please complete the Northwestern Medicine Parkinson’s Disease and Movement Disorders Center online appointment form to discuss next steps.

Feinberg is not a site of care. PDMDC faculty see patients through our affiliated clinic.