Clinical Trials

Inclusion Criteria

• Willing and able to give written informed consent and to comply with trial procedures
• Fulfills diagnostic criteria for idiopathic Parkinson's disease with at least two cardinal signs (resting tremor, bradykinesia, rigidity) present at 2nd screening and baseline evaluations, as assessed by the site Investigator
• Absence of current or imminent (within 90 days of enrollment) disability requiring dopaminergic therapy, as assessed by the site Investigator
• Modified Hoehn and Yahr Scale stage 1 to 2.5 inclusive
• Age 30 or older at the time of diagnosis
• Diagnosis made within 3 years prior to 1st screening visit
• Non-fasting serum urate ≤ 5.7 mg/dL at 1st screening visit
• If the subject is female, then
  • Must be surgically sterile (hysterectomy or tubal ligation)
  • Or postmenopausal (last menstruation was two years or more prior to 2nd screening visit)
  • Or using a reliable form of contraception for 60 days or more prior to baseline visit and agreeing to continue such use for 30 days after last dose of study drug
    •   Reliable forms of contraception include: abstinence; implanted, injected or oral contraceptives (birth control pills), intrauterine device in place for at least 3 months prior to baseline visit, vaginal ring with spermicide, barrier with spermicide such as male or female condom, diaphragm or cervical cap, transdermal patch, male partner with vasectomy
  • Will have a negative pregnancy test at the 2nd screening visit [Note that a urine pregnancy test will be performed at screening on all women who are not at least two years postmenopausal or surgically sterile.]

Exclusion Criteria

• Atypical parkinsonism, including that due to drugs, metabolic disorders, encephalitis, cerebrovascular disease, normal pressure hydrocephalus, or other neurodegenerative disease
• Dopamine transporter (DAT) brain scan without evidence of dopamine deficit
• History of gout
• History of uric acid or urate urolithiasis, or any recurrent urolithiasis of unknown type
• A screening test positive for uric acid crystalluria, urine pH ≤ 5.0, or an estimated glomerular filtration rate < 60 ml/min/1.73 m2
• History of myocardial infarction or stroke
• Symptomatic congestive heart failure with a documented ejection fraction below 45%
• History of severe chronic obstructive pulmonary disease
• Mini Mental State Exam score < 25
• Use of any anti-parkinsonian medication (including levodopa, dopamine agonists, amantadine, entacapone and the anticholinergic agents trihexyphenidyl and benztropine) other than monoamine oxidase-B inhibitors within 60 days of baseline, or in excess of 90 days
• Change in the dosage of (or initiation of) a monoamine oxidase-B (MAO-B) inhibitor within 90 days prior to baseline, i.e., entry on a MAO-B inhibitor requires a stable dosage for the 90 days prior to baseline
• Use of the following within 30 days prior to the baseline visit: inosine, allopurinol, febuxostat, probenecid, more than 50 IU of vitamin E daily, or more than 300 mg of vitamin C daily (though a daily standard multivitamin such as Bayer One-A-Day® or Centrum® is permissible), reserpine, methylphenidate, amphetamines, cinnarizine, monoamine oxidase-A inhibitors, tetrabenazine, neuroleptics or other dopamine blocking drugs
• Use of the following within 90 days prior to the DAT neuroimaging screening evaluation: modafinil, armodafinil, metoclopramide, alpha-methyldopa, methylphenidate, reserpine, or amphetamine derivative
• Unstable dosing of a thiazide -- such as hydrochlorothiazide (e.g., Esidrex), chlorothiazide (e.g., Diuril), chlorthalidone (e.g., Hygroton), indapamide (e.g., Lozol), metolazone (e.g., Zaroxolyn), which are permissible as long as the subject is on a stable dose from 1 week prior to the 1st screening visit through the baseline visit
• Known unstable medical or psychiatric condition that may compromise participation in the study
• Difficulty swallowing large capsules might preclude participation due to the size of the study drug capsules
• Clinically serious abnormality in the screening visit laboratory studies or ECG, as determined by the site Investigator
• Participation in another investigational treatment study within 30 days prior to the baseline visit
• Known hypersensitivity or intolerability to inosine
• Known hypersensitivity to DaTscan (either the active substance of ioflupane I-123 or to any of the excipients)