SLC6A1 study: Glycerol Phenylbutyrate
Official title A Fully Remote Feasibility Trial of Phenylbutyrate for SLC6A1-Related Disorders
ClinicalTrials.gov ID: NCT07847918
What this study is testing
What is Glycerol Phenylbutyrate?
an investigational oral liquid being studied as a potential treatment for SLC6A1‑related disorders
Also referred to as Ravicti, glycerol phenylbutyrate oral liquid, GPB, 4‑phenylbutyrate, 4‑PBA.
Plain-language explanation of the investigational treatment. It is being studied and is not an approved or proven therapy. The study team can confirm the details.
- What it's testing
- This study checks if it is possible to run a clinical trial entirely online without requiring visits to a clinic.
- Who it's for
- People with SLC6A1-related disorders who have seizures and can participate from home in any U.S. state.
- What's involved
- Participants take phenylbutyrate, have remote brain wave tests (EEG), and complete lab tests. Caregivers track seizure counts and report any side effects.
- Time commitment
- The main treatment lasts up to 18 weeks, with the option to continue for up to 3 years with regular check-ins.
- Phase 2: a mid-size study of how well it works
- Time commitment: about 3 years
A plain-language read of the study's public ClinicalTrials.gov listing. The study team confirms the details.
Who can take part
Ages 2 to 60
You may be able to join if
- 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
You likely can't join if
- Larger 3p25 chromosomal deletion extending beyond SLC6A1 and SLC6A11 to encompass additional genes
- Early-infantile developmental and epileptic encephalopathy (DEE) phenotype
- Epileptic spasms within the 6 months prior to enrollment
- Hepatic impairment (AST or ALT \>2× the upper limit of normal)
- Renal impairment (eGFR \<60 mL/min/1.73m²)
- Thrombocytopenia (platelet count \<150 × 10³/μL)
See the full eligibility 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 licensed physician identified for ordering laboratory testing, EEG, and clinical evaluation as needed
- English-speaking caregiver for consent and study communication
- Larger 3p25 chromosomal deletion extending beyond SLC6A1 and SLC6A11 to encompass additional genes
- Early-infantile developmental and epileptic encephalopathy (DEE) phenotype
- Epileptic spasms within the 6 months prior to enrollment
- Hepatic impairment (AST or ALT \>2× the upper limit of normal)
- Renal impairment (eGFR \<60 mL/min/1.73m²)
- Thrombocytopenia (platelet count \<150 × 10³/μL)
- Inborn errors of beta-oxidation
- Pancreatic insufficiency or intestinal malabsorption
- Known hypersensitivity to phenylbutyrate or any of its components
- Participation in another treatment investigational study within 30 days or 5 half-lives of the investigational product, whichever is longer
- Current use of alfentanil, quinidine, cyclosporine, or probenecid due to clinically significant interactions with phenylbutyrate based on CYP3A4 modulation
- Pregnancy or breastfeeding
- Any condition that in the investigator's judgment would interfere with study participation or safety monitoring This is a fully remote study. Participants may enroll from any U.S. state. No facility visit is required.
The study team makes the final eligibility decision.
Where it is enrolling
- San Diego, California, United States
Questions & answers
Do participants get paid in this trial?
This listing doesn't specify compensation. Many trials still reimburse travel or offer a stipend, so it's worth asking the study team when you connect.
Is it free to join, and do I need insurance?
Searching and applying through BridgeMD is free. In clinical trials the study-related treatment and visits are generally provided at no cost to you. You usually don't need insurance to take part, but confirm specifics with the study team.
How long does this study last?
The study runs about 3 years per participant, based on its public description. The team confirms the exact schedule and number of visits before you enroll.
Who can join this trial?
This study is enrolling all sexes, 2 years to 60 years. The study team makes the final eligibility decision.
Where is this trial taking place?
This study is enrolling now at San Diego, California, United States. Enter your location above to see the nearest enrolling site and check your eligibility.
Explore other conditions
BridgeMD is an information and trial-matching tool that is independent of the study sponsor. Details come from ClinicalTrials.gov. The study team decides eligibility, and your own doctor gives medical advice.