A Fully Remote Feasibility Trial of Phenylbutyrate for SLC6A1-Related Disorders

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.