Research in Movement Disorders

Efficacy and Safety of Amantadine HCl Extended Release Tablets in Parkinson's Disease Subjects With Levodopa-Induced Dyskinesias (OS320-3006)

[Study Sponsor: Osmotica Pharmaceutical Corp.; Principal Investigator: Scott Sherman, MD, PhD]

The purpose of this multi-center, randomized, double-blind, parallel-group, 26 week study is to compare the efficacy and safety of two different dose levels of Amantadine Extended Release Tablets to placebo for the treatment of levodopa induced dyskinesia in patients with Parkinson's disease.

The dose will be given once a day in the morning so that amantadine concentrations are maintained throughout the day for treating the levodopa induced dyskinesia, but will be lower during the night, potentially reducing the negative impact of amantadine on sleep.

Inclusion Criteria:

  • Male or female 30 to 85 years old.
  • Levodopa induced, predictable peak-effect dyskinesia considered problematic and/or disabling.
  • On stable doses of all oral anti-Parkinson's medication, including any levodopa preparation, for 30 days and be willing to remain on the same doses throughout the trial.
  • The subject/caregiver must demonstrate the ability to complete an accurate home diary based on training and evaluation during the screening period.

A Phase III, 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 (KW-6002-014)

[Study Sponsor: Kyowa Hakko Kirin Pharma, Inc.; Principal Investigator: Scott Sherman, MD, PhD]

This is a study to assess the efficacy and safety of oral Istradefylline (KW-6002) in patients with moderate to severe Parkinson's Disease. While on this study, participants will continue to take their usual, prescribed, stable regimen of Levodopa/Carbidopa or Levodopa/Benserazide therapy plus adjunct Parkinson's medications. 

Patients will be randomized 1:1:1 to receive either Istradefylline 20 mg per day, or Istradefylline 40 mg per day or an equivalent placebo.

Patients will be treated for a 12 week period to demonstrate the effectiveness of Istradefylline in improving Parkinson's disease symptoms (referred to as improvement in patient OFF time) and that Istradefylline has an acceptable safety profile in this group.

Patients who meet the following criteria could be eligible to participate:

  • 30 years of age or older
  • Treatment with levodopa therapy for at least 1 year
  • Documented end-of-dose wearing-off and levodopa-induced dyskinesia                                                                                                           

This study is also on Once you access this page, look for identifier: NCT01968031


Sabrina D'souza, BS
Research Technician
(520) 626-4537
University of Arizona, Health Science Center, Department of Neurology
1501 N. Campbell Avenue, Room 7329
Tucson, AZ 85724-5023
Fax: 520-626-4903