Scripps Translational Science Institute
The purpose of this study is to evaluate the feasibility of a site-less (fully remote) clinical trial using phenylbutyrate for SLC6A1-related disorders. Study participants will receive treatment with phenylbutyrate, undergo electroencephalogram (EEG) monitoring, and complete laboratory testing. Caregivers will report seizure frequency, answer questionnaires, and report side effects. Participants will be randomly assigned to one of two groups. Randomization is stratified by age band (\<7 years vs. ≥7 years) and baseline seizure frequency (≤5 vs. \>5 daily seizures). One group will begin treatment immediately; the other group will have a 6-week observation period before starting treatment. All participants will receive phenylbutyrate. Treatment lasts up to 18 weeks with the option to extend for up to 3 years. Follow-up occurs at 18 weeks. If extending treatment, additional follow-up occurs at 6 months, 1 year, and then annually. Participation is completely voluntary. There is the risk of adverse events from the study drug, phenylbutyrate, including hospitalization from metabolic acidosis. There is the risk of loss of confidentiality of your medical and personal information collected for this study. This study does not replace emergency medical care. This is a fully remote study. Participants may enroll from any U.S. state. No facility visit is required.
The purpose of this study is to determine whether a site-less (fully remote) clinical trial design, one conducted entirely remotely without a physical clinic site, is feasible for families affected by SLC6A1-related disorders. A secondary purpose is to explore the safety, tolerability, and preliminary effectiveness of phenylbutyrate in this population. SLC6A1-related disorder is a rare genetic condition that causes epilepsy and intellectual disability. It is caused by variants in the SLC6A1 gene, which encodes a protein called GABA transporter 1 (GAT-1) that helps regulate the brain chemical…
Inclusion Criteria: * Confirmed diagnosis of SLC6A1-related disorder based on a pathogenic or likely pathogenic variant in the SLC6A1 gene * Age 2-60 years at time of consent * Active clinical seizures, defined as ≥4 seizures in the 4 weeks prior to enrollment * Seizures persisting despite an adequate trial of ≥2 prior antiseizure medications at therapeutic doses * Stable antiseizure medication regimen for ≥4 weeks prior to enrollment * Parent, legal guardian, or legally authorized representative (LAR) able to provide informed consent and participate in digital follow-up assessments * Local l…
Glycerol phenylbutyrate oral liquid (1.1 g/mL) administered orally three times daily with food or formula, or via gastrostomy or nasogastric tube when clinically indicated. The dose is titrated over 8 weeks from a starting dose of 3.6 mL/m²/day to a target maximum of 11.2 mL/m²/day (12.4 g/m²/day), not to exceed 17.5 mL/day total, based on body surface area. Dose adjustments are made based on tolerability and safety laboratory results. Drug is obtained through self-pay via Cost Plus pharmacy with direct home delivery, or through the participant's health insurance at a designated pharmacy. Other Name(s): Ravicti; glycerol phenylbutyrate oral liquid; GPB; 4-phenylbutyrate; 4-PBA