Long Term Study of Istradefylline in Subjects With Moderate to Severe Parkinson's Disease
Condition: Idiopathic Parkinson's Disease
MeSH terms: Parkinson Disease
Intervention: Istradefylline 20 mg or 40 mg
Intervention description: Istradefylline 20 or 40 mg
Intervention MeSH terms: Istradefylline
Phase: Phase 3
Study type: Interventional
Primary purpose: Treatment
Intervention model: Single Group Assignment
Masking: None (Open Label)
Enrollment: 239.0
Sex: All
Minimum age: 30 Years
Healthy volunteers: No
Keywords: Parkinson's disease; Moderate to Severe Parkinson's Disease

Summary:

      This is a Phase 3, 52-week, open-label, flexible-dose, multinational, multicenter study to
      evaluate the safety and tolerability of istradefylline 20 or 40 mg/d in subjects with
      moderate to severe PD with motor fluctuations and dyskinesia on levodopa combination
      (levodopa/carbidopa or levodopa/benserazide) therapy plus at least one adjunctive PD
      medication. Subjects who completed 12 weeks of double-blind treatment and the 30-day
      follow-up period in Study No. 6002-014 will undergo Screening and Baseline evaluations for
      eligibility for the study. Eligible subjects will be treated with istradefylline at a
      starting dose of 20 mg/d with an option for a dose adjustment to 40 mg/d at Week 12 based on
      the Investigator's judgment of each subject's response and tolerability. If deemed necessary,
      one unscheduled dose adjustment visit between Week 2 to Week 12 is allowed in accordance with
      clinical judgment of the Investigator. Subjects who had a dose adjustment to 40 mg/d can have
      their dose decreased to 20 mg/d by the Investigator at a second unscheduled dose adjustment
      visit if there are tolerability issues. The istradefylline dose should remain fixed between
      Week 26 to Week 52. Consultation with the Sponsor's Medical Monitor is required prior to any
      unscheduled dose adjustment visits. A subject may discontinue from the study at any time.
    

Eligibility criteria:

        Inclusion Criteria:

          1. Written informed consent;

          2. Subjects who completed Study No. 6002-014 inclusive of the 30-day follow-up period;

          3. Currently taking levodopa combination (carbidopa/levodopa or benserazide/levodopa)
             therapy plus at least one adjunctive PD medication;

          4. Women of child-bearing potential (WOCBP) must use a reliable method of contraception
             and have a negative serum pregnancy test at Screening;

        Exclusion Criteria:

          1. Subjects with less than 70% treatment compliance throughout their enrollment on Study
             No 6002-014 and or with major protocol deviations in Study No. 6002-014 (subjects who
             failed to meet any of the inclusion criteria, subjects who met any of the exclusion
             criteria or subjects who met the criteria for subject withdrawal but who were not
             withdrawn);

          2. Subjects on apomorphine and/or dopamine receptor antagonists or direct
             gastrointestinal levodopa infusion;

          3. Subject who have had neurosurgical operation for PD;

          4. Subjects taking A2a antagonist, potent CYP3A4 inhibitors, potent CYP34A inducers;

          5. Subjects who have had a diagnosis of cancer or evidence of continued malignancy within
             the past three years (with the exception of adequately treated basal cell or squamous
             cell skin cancer, in situ cervical cancer, or in situ prostate cancer with normal
             prostate-specific antigens post resection).