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

Active, No Longer Recruiting
University of Colorado, Denver
Study Design: 
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.
PRIMARY OUTCOME MEASURE: Levels of α-synuclein in blood plasma. SECONDARY OUTCOME MEASURES: Not listed.
This is an open label proof of principle study. The study has been completed but the results have not been published. The team is pursuing a Phase II dose selection study.