Active — Not RecruitingEarly Phase 1

Phenylbutyrate for Monogenetic Developmental and Epileptic Encephalopathy

United States50 participantsStarted 2021-03-01

Plain-language summary

This study is to evaluate the use of glycerol phenylbutyrate for monogenetic developmental epileptic encephalopathies (DEEs). DEEs are characterized by epilepsy and developmental delay in early life. Two examples of DEEs are STXBP1 and SLC6A1, though there are dozens of others. STXBP1 Encephalopathy is a severe disease that can cause seizures and developmental delays in infants and children. SLC6A1 neurodevelopmental disorder is characterized by developmental delay and often epilepsy. Both STXBP1 encephalopathy and SLC6A1 neurodevelopmental disorder cause symptoms because there are not enough working proteins made by these genes. It is possible that a medication called phenylbutyrate may help the the remaining proteins work better for STXBP1, SLC6A1, and/or other similar DEEs caused by single genes (i.e. "monogenetic"). This study is to test if glycerol phenylbutyrate is safe and well tolerated in children with monogenetic DEE.

Who can participate

Age range

0 Months – 17 Years

Sex

ALL

See this in plain English?

AI-rewrites the medical criteria so a patient or caregiver can understand them. Always confirm with the trial site.

\###### STXBP1 / SLC6A1 ARM Inclusion Criteria: * Diagnosed with STXBP1-E or SLC6A1-NDD; confirmed by laboratory report (i.e., a genetic test with a pathogenic or likely pathogenic mutation of STXBP1 or SLC6A1-NDD and a clinical picture consistent with the disorder, as determined by the Investigator). Patients with the appropriate clinical picture, a de novo variant of uncertain significance in STXBP1 or SLC6A1-NDD will also be eligible for enrollment, at the discretion of the Investigator. * Is between 2 months and 17 years of age, inclusive. * For children with STXBP1-E, the child must have had at least one seizure in the past 30 days prior to enrollment. If there is high demand for the study and we have several subjects to choose, we will prefer to enroll children with a high number of seizures in the past month. * For SLC6A1-NDD, seizures occur later in the course (typically middle of 1st decade) and so seizures will not be an entry criteria. * Is in general good health, aside from neurological consequences of STXBP1-E or SLC6A1-NDD, as determined by having no concurrent medical illness, in the opinion of the site investigator, that places the subject at increased risk of adverse drug reactions or that will interfere with study follow-up. * Has normal laboratory test results (≤ 1.5 × upper limit of normal \[ULN\]) for serum aminotransferase (aspartate aminotransferas \[AST\] and alanine aminotransferase \[ALT\]) concentrations and ammonia at Screening. * Has normal rena…

Questions worth asking your doctor

Bring these to your next appointment. They're a starting point for a shared conversation — not a sign you qualify or a recommendation to enrol.

1Based on my diagnosis and history, is this trial worth exploring for me — or is there a standard treatment we should try first?
2What does this trial's phase tell us about how much is already known about its safety and benefit?
3What would taking part actually involve for me — visits, tests, time, and travel?
4What are the known and possible risks or side effects I should weigh, and how would they be monitored?
5If this trial isn't the right fit, what other options or trials would you suggest I look into?

Generated to help you prepare — always confirm anything about your own eligibility and care with the study team and your doctor.

Questions for the trial coordinator

The trial coordinator is the person who runs the study day to day. These cover the practical side — logistics, costs, and what taking part would actually mean for your life. The study team confirms whether you meet the criteria; these are questions to ask, not a sign you qualify.

1What does taking part actually involve week to week — how many visits, where, and how long does each one take?
2What costs are covered by the study, and what might I have to pay for myself, including travel, parking, or time off work?
3What happens during screening, and what happens if the study team confirms I don't meet the criteria after those tests?
4Who pays for the scans, blood work, and other tests the trial requires — the study, my insurance, or me?
5How will being in the trial affect my regular care, and will my own doctor stay informed and involved?
6Can I leave the trial at any point if I change my mind, and what would happen to my care if I do?

A starting point for the conversation — always confirm anything about your own eligibility, costs, and care with the study team and your doctor.

What they're measuring

Short Term Adverse events (i.e., safety)

Timeframe: 20 weeks

Long Term Adverse events (i.e., safety)

Timeframe: through December 2025 (1 - 5 years, depending on participant)

Percentage of doses taken by participants (i.e., tolerability)

Timeframe: 20 weeks

Trial details

NCT IDNCT04937062

SponsorWeill Medical College of Cornell University

Sponsor typeOTHER

Study typeINTERVENTIONAL

Primary completion2026-12-01

View on ClinicalTrials.gov More STXBP1 Encephalopathy With Epilepsy, SLC6A1 Neurodevelopmental Disorder trials