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

HS 2013-9898
Parkinsons, Brain & Nerve
Neal Hermanowicz, MD
UC Irvine Campus
The purpose of this study is to test the safety and effectiveness of an investigational study drug, istradefylline, in patients with Parkinson’s disease who have been optimally or maximally treated with levodopa/carbidopa therapy.

  • Are 30 years of age and older, with idiopathic Parkinson’s disease.
  • Are able to provide written consent to participate.
  • Have had levodopa therapy for at least 1 year and continue to respond well to the treatment.
  • Are taking levodopa combinations (carbidopa/levodopa or benserazide/levodopa) at a daily dose of at least 400 mg plus a recommended, clinically effective dose of at least one adjunctive medication approved to treat Parkinson’s disease.
  • Women of childbearing potential must agree to use a reliable method of contraception (e.g., birth control pill or long-term injectable or implantable hormonal contraceptive, double barrier methods [such as condom plus diaphragm, condom plus spermicide foam, condom plus sponge, or intra-uterine device (birth control device inside the uterus)], and have a negative pregnancy test.
Please note this is only a partial list of eligibility.
Subjects must be able to commit up to approximately 18 weeks, which will involve seven (7) visits to the clinic and one (1) phone follow-up. The first three (3) visits will take approximately three to four hours. The next three visits will take approximately two to three hours. The last visit could take up to six hours.
Taking part in this study may or may not improve Parkinson’s disease. While doctors hope istradefylline will be useful in treating symptoms of Parkinson’s disease by decreasing “OFF” time, there is no proof of this yet.
Subjects will be reimbursed $50 for visits one, two, four, five, and six; $125 for visit three, and $150 for visit seven, per completed visit. This is to help cover the cost of travel and meals. Total compensation for participation in the entire study will be up to $525.
Kyowa: Istradefylline
Drug therapy
Katrina Samson