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Phenylbutyrate Response as a Biomarker for Alpha-synuclein Clearance From the Brain

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ClinicalTrials.gov Identifier: NCT02046434
Recruitment Status : Completed
First Posted : January 27, 2014
Last Update Posted : April 25, 2022
Information provided by (Responsible Party):
University of Colorado, Denver

Brief Summary:
This is a Phase I clinical trial of the FDA approved drug Glycerol Phenylbutyrate to see if phenylbutyrate can increase the removal of alpha-synuclein from the brain into the bloodstream. Alpha-synuclein forms abnormal protein deposits in dopamine neurons and is believed to cause the death of brain cells, leading to Parkinson's Disease.

Condition or disease Intervention/treatment Phase
Parkinson's Disease Drug: Glycerol Phenylbutyrate Phase 1

Detailed Description:
This is a Phase I clinical trial of phenylbutyrate in 20 Parkinson patients and 20 age- and sex-matched normal control subjects to see if phenylbutyrate can increase the removal of alpha-synuclein from the brain into the bloodstream. All subjects will receive 20 grams/day of phenylbutyrate in the liquid form phenylbutyrate-triglyceride taken as one teaspoonful three times per day with meals. Blood will be drawn on two days prior to starting phenylbutyrate to measure alpha-synuclein concentrations. Phenylbutyrate-triglyceride will then be started and the change in plasma alpha-synuclein will be measured on day 1, 7, 14, and 21 days while taking phenylbutyrate. After 21 days, the drug will be stopped and a final blood sample will be measured at 28 days to see if plasma alpha-synuclein has fallen to its pre-phenylbutyrate level. No effects on Parkinson symptoms are expected during this short trial. Please note that although taking any type of Parkinson's drugs for symptomatic treatment disqualifies you, if you and your neurologist are willing and able to have you off Parkinson medication for six weeks before and during the trial, you may be eligible to participate.

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Study Type : Interventional  (Clinical Trial)
Actual Enrollment : 38 participants
Allocation: Non-Randomized
Intervention Model: Parallel Assignment
Masking: None (Open Label)
Primary Purpose: Treatment
Official Title: Phenylbutyrate Response As a Biomarker for Alpha-Synuclein Clearance From Brain
Actual Study Start Date : January 2014
Actual Primary Completion Date : September 2019
Actual Study Completion Date : September 2019

Resource links provided by the National Library of Medicine

Arm Intervention/treatment
Experimental: Parkinson's Diesase
Participant will take Glycerol Phenylbutyrate, participant has Parkinson's Disease
Drug: Glycerol Phenylbutyrate
Other Name: Ravicti

Experimental: Control
Participant does not have Parkinson's Disease, Participant will be taking glycerol phenylbutyrate
Drug: Glycerol Phenylbutyrate
Other Name: Ravicti

Primary Outcome Measures :
  1. Levels of alpha-synuclein in blood plasma [ Time Frame: 1 month ]

Information from the National Library of Medicine

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Ages Eligible for Study:   21 Years to 80 Years   (Adult, Older Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   Yes

Inclusion Criteria:

  • Idiopathic Parkinson's disease with mild symptoms;
  • May be on treatment with dopamine agonists provided that the treating neurologist agrees:

    1. that the drugs can be stopped for at least three weeks prior to participating in the phenylbutyrate study, and
    2. for the 4-week duration of the study.
  • Age and sex matched normal control subjects from spouses and the general population;
  • In good general health;
  • Controlled hypertension, or
  • Controlled hypercholesterolemia with medication.

Exclusion Criteria:

  • Pregnant women;
  • Current treatment with:

    1. L-3,4-dihydroxyphenylalanine (L-DOPA);
    2. monoamine oxidase (MAO) inhibitors,
    3. catechol-O-methyl transferase (COMT) inhibitors;
    4. histone deacetylase (HDAC) inhibitors;
    5. prednisone or other corticosteroids, or
    6. probenecid.
  • Severe cardiopulmonary disease such as:

    1. congestive heart failure, or
    2. emphysema requiring supplemental oxygen;
  • Renal disease with serum creatinine greater than 2.5;
  • History of:

    1. depression in the prior year;
    2. epilepsy;
    3. stroke;
    4. prior brain surgery;
    5. dementia, or
    6. psychosis.

Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its ClinicalTrials.gov identifier (NCT number): NCT02046434

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United States, Colorado
University of Colorado Denver Anschutz Medical Center
Aurora, Colorado, United States, 80045
Sponsors and Collaborators
University of Colorado, Denver
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Principal Investigator: Curt R Freed, MD University of Colorado, Denver
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Responsible Party: University of Colorado, Denver
ClinicalTrials.gov Identifier: NCT02046434    
Other Study ID Numbers: 13-2808
First Posted: January 27, 2014    Key Record Dates
Last Update Posted: April 25, 2022
Last Verified: April 2022
Additional relevant MeSH terms:
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Parkinson Disease
Parkinsonian Disorders
Basal Ganglia Diseases
Brain Diseases
Central Nervous System Diseases
Nervous System Diseases
Movement Disorders
Neurodegenerative Diseases
4-phenylbutyric acid
Cryoprotective Agents
Protective Agents
Physiological Effects of Drugs
Antineoplastic Agents