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STXBP1 Encephalopathy With Epilepsy, SLC6A1 Neurodevelopmental DisorderEarly Phase 1NCT04937062

Phenylbutyrate for Monogenetic Developmental and Epileptic Encephalopathy

A Early Phase 1 study testing Glycerol Phenylbutyrate 1100 MG/ML [Ravicti] in people with STXBP1 Encephalopathy With Epilepsy, SLC6A1 Neurodevelopmental Disorder and Developmental and Epileptic Encephalopathy, run by Weill Medical College of Cornell University at 2 sites in United States.

Active, not recruiting

Under way, not looking for participants. Everyone needed has enrolled. The study is still running.

Official record
Search all trials

Trial 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. Read more about this study

Who is it for?
Ages 0 months to 17 years
What is being tested?
Glycerol Phenylbutyrate 1100 MG/ML [Ravicti]
Type of treatment
Pill or oral medicine
Could I receive a placebo?
No, everyone receives an active treatment
How many people
50 participants
Where
2 sitesUnited States
Study dates
1 Mar 2021to 31 Dec 2026
Phase
Early Phase 1
Are there results?
Not yet: the study is under way

Key requirements

Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.

  • Ages 0 months to 17 years
  • All sexes
  • No healthy volunteers
  • Child

Who may be able to join

  • 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.
Show all 10Show fewer
  • Has normal renal function, with estimated glomerular filtration rate > 90 mL/minute/1.73 m2 at Screening (using the Chronic Kidney Disease Epidemiology Collaboration equation).
  • Has a platelet count > 150 × 103/μL at Screening.
  • Has a QT interval corrected with Fridericia's formula (QTcF) < 450 msec on the Screening EKG.
  • Parent or guardian is able to comprehend and willing to sign an informed consent form (ICF).

Who cannot join

  • Has participated in another investigational study within 30 days or 5 half-lives of the test drug's biologic activity (whichever is longer) before the first study drug dose.
  • Has a QT interval corrected with Fridericia's formula (QTcF) ≥ 450 msec on the Screening EKG.
  • Has an active medical illness that would preclude participation in the study (as determined by the Investigator).
  • Has a clinical laboratory evaluation outside of the test laboratory reference range, unless deemed not clinically significant by the Investigator and the Sponsor.
  • Is unable to comply with the study protocol.
  • Has poor venous access and/or cannot tolerate venipuncture.
Show all 34Show fewer
  • Is pregnant
  • Is a female of child-bearing age (12 years old or older) and known to be sexually active (for example, as determined through a confidential HEADDSSS history), and not taking medication for contraception. This will be assessed confidentially as per good general pediatrics practice
  • Known hypersensitivity to phenylbutyrate. Signs of hypersensitivity include wheezing, dyspnea, coughing, hypotension, flushing, nausea, and rash.
  • Taking alfentanil, quinidine, cyclosporine, or probenecid (known interactions with phenylbutyrate). For subjects who had taken any of these medications in the past, the last dose must have been taken at least 1 week prior to enrollment into the study.
  • Inborn errors of beta oxidation.
  • Pancreatic insufficiency or intestinal malabsorption
  • ###### MONOGENETIC DEE ARM Inclusion Criteria
  • Diagnosed with a monogenic developmental and epileptic encephalopathy; confirmed by laboratory report (i.e., a genetic test with a pathogenic or likely pathogenic mutation of a monogenic developmental and epileptic encephalopathy and a clinical picture consistent with the disorder, as determined by the Investigator). Children with the appropriate clinical picture, a de novo variant of uncertain significance in a monogenic developmental and epileptic encephalopathy will also be eligible for enrollment, at the discretion of the Investigator. If the mutant is classified as definitively non-pathogenic, we would not enroll the child. "Appropriate clinical picture" is at the discretion of the Investigator.
  • Is between 0 months and 15 years of age, inclusive.
  • 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.)
  • Is in general good health, aside from neurological consequences of their monogenic developmental and epileptic encephalopathy, 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.
  • Has normal renal function, with estimated glomerular filtration rate > 90 mL/minute/1.73 m2 at Screening (using the Chronic Kidney Disease Epidemiology Collaboration equation).
  • Has a platelet count > 150 × 103/μL at Screening.
  • Has a QT interval corrected with Fridericia's formula (QTcF) < 450 msec on the Screening EKG.
  • Parent or guardian is able to comprehend and willing to sign an informed consent form (ICF).
  • Has participated in another investigational study within 30 days or 5 half-lives of the test drug's biologic activity (whichever is longer) before the first study drug dose.
  • Has a QT interval corrected with Fridericia's formula (QTcF) ≥ 450 msec on the Screening EKG.
  • Has an active medical illness that would preclude participation in the study (as determined by the Investigator).
  • Has a clinical laboratory evaluation outside of the test laboratory reference range, unless deemed not clinically significant by the Investigator and the Sponsor.
  • Is unable to comply with the study protocol.
  • Has poor venous access and/or cannot tolerate venipuncture.
  • Is pregnant
  • Is a female of child-bearing age (12 years old or older) and known to be sexually active (for example, as determined through a confidential HEADDSSS history), and not taking medication for contraception. This will be assessed confidentially as per good general pediatrics practice
  • Known hypersensitivity to phenylbutyrate. Signs of hypersensitivity include wheezing, dyspnea, coughing, hypotension, flushing, nausea, and rash.
  • Taking alfentanil, quinidine, cyclosporine, or probenecid (known interactions with phenylbutyrate). For subjects who had taken any of these medications in the past, the last dose must have been taken at least 1 week prior to enrollment into the study.
  • Inborn errors of beta oxidation.
  • Pancreatic insufficiency or intestinal malabsorption

Trial locations and contacts

2 sites in 1 country.

United States2 sites

  • Children's Hospital Colorado

    Aurora, Colorado, 80045

  • Weill Cornell Medicine

    New York, New York, 10065

Other trials in United States

About this study

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.

Read more

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.

Read the detailed description

STXBP1 encephalopathy (STXBP1-E) is a devastating neurodevelopmental disorder that often begins in infancy. Intellectual disability is a core feature, often severe to profound. Nearly all have epilepsy (95% in the largest series). The epilepsy is clinically heterogeneous, and may present as a well-defined epilepsy syndrome (e.g., early infantile epileptic encephalopathy, infantile spasms, epilepsy of infancy migrating focal seizure, or Dravet syndrome) or as non-syndromic epilepsy. Seizures are refractory to medications in one third. Affected individuals may have autistic features (1 in 5), low tone, movement disorders (including ataxia and bruxism), abnormal EEGs (> 60% with focal or multifocal epileptiform discharges), and/or abnormal MRI brain imaging (atrophy, thin corpus callosum, delayed myelination). The clinical spectrum is broad -- some individuals are profoundly impaired with seizures that begin in the first days of life; whereas others may have a few seizures in late infancy and mild learning difficulties.

STXBP1 knockout mice show normal early brain assembly with subsequent degeneration, decreased neurite outgrowth, and completely abolished neurotransmitter release These mice die shortly after birth. Heterozygous STXBP1 mice are similar to wild-type, except they have abnormal behaviors during sleep (twitches and jumps) and EEG abnormalities. Thus, heterozygous STXBP1 mice recapitulate some aspects of the human disease, though they have neither seizures nor overt behavioral abnormalities. Human embryonic stem cell-derived neurons engineered for STXBP1 loss of function exhibit normal initial synaptogenesis, synapse size, and soma size; however, heterozygotes show decreased neurotransmitter release corresponding to decreased STXBP1 levels, while homozygous loss of function causes significant neural degeneration. Published experiments on neuronal lines derived from affected patients show decreased STXBP1 protein, STXBP1 protein mislocalization, and decreased neurite outgrowth. Early work in heterologous cell lines demonstrated STXBP1 mutations cause protein misfolding that leads to aggregation of the mutant protein with wild-type STXBP1.

In laboratory settings, stabilizing protein folding of the STXBP1 protein product with chemical chaperones rescued molecular and functional deficits in all tested models, using any of three chemical chaperones: sorbitol, trehalose, and 4-phenylbutyrate. Sorbitol and trehalose are sugars, and would be metabolized in the gut. 4-phenylbutyrate, however, is available as an FDA approved medication, either via sodium phenylbutyrate or glycerol phenylbutyrate. The glycerol formulation is better tolerated, thus this trial.

SLC6A1-related neurodevelopmental disorder (SLC6A1-NDD) begins in early childhood and is characterized by epilepsy (~91%, typically generalized) and developmental delay (~82%). The epilepsy is typically generalized (absence, atonic, myoclonic, generalized tonic-clonic) though is sometimes focal. Substantial minorities have an autism spectrum disorder, movement disorder, or problems with attention or aggression.

The protein product of SLC6A1 is GABA transporter protein type 1 (GAT-1), which is important for GABA homeostasis in the brain. Pathogenic mutations in SLC6A1 lead to loss of function and haploinsufficiency. Preliminary data suggests a dramatic impairment in GABA uptake in cells with homozygous variants in the GAT-1 protein, which improves with administration of phenylbutyrate.

The investigators began studying phenylbutyrate for STXBP1-E and SLC6A1-NDD with a pilot study (i.e. Phase 1 study) in order to (a) understand safety and tolerability of the medication in children with STXBP1-E and SLC6A1-NDD, (b) understand the peak plasma concentrations in order to estimate CSF levels, and (c) generate exploratory information about clinical outcomes as a means to estimate effect sizes and pilot a battery of clinical testing for STXBP1-E and SLC6A1-NDD for future trials.

Based on additional publications and ongoing research, the study the study has expanded in scope to (a) follow enrolled children for a longer time and (b) broaden the enrollment criteria to include monogenetic DEEs.

Being tested
Glycerol Phenylbutyrate 1100 MG/ML [Ravicti]
Keywords
phenylbutyrate, developmental and epileptic encephalopathy
Medical subject headings
Epileptic Encephalopathy, Early Infantile, 4

What participants receive

What participants receive. In a randomised study each person is assigned to one group by chance.

  • Glycerol Phenylbutyrate 1100 MG/ML [Ravicti]Drug

    Glycerol phenylbutyrate (trade name "Ravicti") is an FDA-approved medication used for urea cycle disorders in children and adults. We will titrate to a goal dose of 1.2 mL/m2 (12.4 g/m2) in three equally divided doses given enterally (i.e., by mouth or by g-tube).

    The dosing is consistent with the dosing guidelines in the FDA approved Medication Guide (https://www.accessdata.fda.gov/drugsatfda_docs/label/2017/203284s005lbl.pdf).

Study groups in NCT04937062
Study groupRoleWhat they receive
SLC6A1 and STXBP1ExperimentalEach participant will be enrolled for 14 weeks (4 weeks baseline, 8 weeks of drug exposure, and 2 weeks follow-up). After clinical assessment by the investigator if deemed safe and appropriate, and requested by the caregiver, participants may continue to receive the study medication ("extended use"), up to December 2025. Participants who remain on phenylbutyrate therapy will be followed quarterly through video visits, and yearly in-person visit. Participants who do not opt to remain on phenylbutyrate therapy will be weaned off the medication during the 2 week follow-up period.
Receives: Drug: Glycerol Phenylbutyrate 1100 MG/ML [Ravicti]
Monogenetic Epileptic EncephalopathyExperimentalEach participant will be enrolled for 20 weeks (5 weeks baseline, 12 weeks of drug exposure, and 2 weeks follow-up) . After clinical assessment by the investigator if deemed safe and appropriate, and requested by the caregiver, participants may continue to receive the study medication ("extended use"), up to December 2025. Participants who remain on phenylbutyrate therapy will be followed quarterly through video visits, and yearly in-person visit. Participants who do not opt to remain on phenylbutyrate therapy will be weaned off the medication during the 2 week follow-up period.
Receives: Drug: Glycerol Phenylbutyrate 1100 MG/ML [Ravicti]

What is being measured

The primary outcome is the main question the study is designed to answer.

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

    The qualitative safety endpoint will describe any adverse events. It will include a description of the incidence, frequency, and severity of adverse events (including known side effects of the medication, changes in vital signs, EKG changes, EEG changes, increase in seizures, changes in clinical laboratory results, and/or changes in physical examination). We will monitor for these adverse events throughout the study, and measure them definitely at the time of the second admission.

    Measured: 20 weeks

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

    The long term qualitative safety endpoint will describe any adverse events. It will include a description of the incidence, frequency, and severity of adverse events (including known side effects of the medication, changes in vital signs, EKG changes, EEG changes, increase in seizures, changes in clinical laboratory results, and/or changes in physical examination). We will monitor for these adverse events throughout the study, and measure them yearly until December 2025.

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

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

    The tolerability endpoint is quantitative and will measure medication compliance (i.e. what percentage of the doses are taken).

    Measured: 20 weeks

Secondary outcomes (1)

  1. Plasma concentration of phenylbutyrate

    We will measure the plasma concentration of phenylbutyrate at the second inpatient admission.

    Measured: 20 weeks

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

  1. First posted23 Jun 2021
  2. Study start1 Mar 2021
  3. Primary completion1 Dec 2026 (estimated)
  4. Study completion31 Dec 2026 (estimated)

Resources

More details

For doctors and researchers: how the study is designed, who runs it, and its registry IDs.

Study design
Study type
Interventional
Phase
Early Phase 1
Primary purpose
Treatment
Allocation
Non-randomised
Intervention model
Single group
Model description
This is a pilot, single treatment, multiple-dose, open label, study to be conducted in up to 10 children with STXBP1-E, and 10 with SLC6A1-NDD, and 30 children with monogenetic developmental and epileptic encephalopathy.
Masking
None (open label)
Enrolment
50 participants (estimated)
IDs, dates and publications
ClinicalTrials.gov ID
NCT04937062
Sponsor's protocol ID
19-10020997
Status last verified
Jan 2026
First submitted
10 Jun 2021
Last updated
22 Jan 2026
Results posted
No
Data monitoring committee
Yes
FDA-regulated drug
Yes
FDA-regulated device
No
Individual data sharing
No

Publications

  • Rezazadeh A, Uddin M, Snead OC 3rd, Lira V, Silberberg A, Weiss S, Donner EJ, Zak M, Bradbury L, Scherer SW, Fasano A, Andrade DM. STXBP1 encephalopathy is associated with awake bruxism. Epilepsy Behav. 2019 Mar;92:121-124. doi: 10.1016/j.yebeh.2018.12.018. Epub 2019 Jan 14.

    PubMed 30654231

  • Stamberger H, Nikanorova M, Willemsen MH, Accorsi P, Angriman M, Baier H, Benkel-Herrenbrueck I, Benoit V, Budetta M, Caliebe A, Cantalupo G, Capovilla G, Casara G, Courage C, Deprez M, Destree A, Dilena R, Erasmus CE, Fannemel M, Fjaer R, Giordano L, Helbig KL, Heyne HO, Klepper J, Kluger GJ, Lederer D, Lodi M, Maier O, Merkenschlager A, Michelberger N, Minetti C, Muhle H, Phalin J, Ramsey K, Romeo A, Schallner J, Schanze I, Shinawi M, Sleegers K, Sterbova K, Syrbe S, Traverso M, Tzschach A, Uldall P, Van Coster R, Verhelst H, Viri M, Winter S, Wolff M, Zenker M, Zoccante L, De Jonghe P, Helbig I, Striano P, Lemke JR, Moller RS, Weckhuysen S. STXBP1 encephalopathy: A neurodevelopmental disorder including epilepsy. Neurology. 2016 Mar 8;86(10):954-62. doi: 10.1212/WNL.0000000000002457. Epub 2016 Feb 10.

    PubMed 26865513

  • Saitsu H, Kato M, Mizuguchi T, Hamada K, Osaka H, Tohyama J, Uruno K, Kumada S, Nishiyama K, Nishimura A, Okada I, Yoshimura Y, Hirai S, Kumada T, Hayasaka K, Fukuda A, Ogata K, Matsumoto N. De novo mutations in the gene encoding STXBP1 (MUNC18-1) cause early infantile epileptic encephalopathy. Nat Genet. 2008 Jun;40(6):782-8. doi: 10.1038/ng.150. Epub 2008 May 11.

    PubMed 18469812

  • Di Meglio C, Lesca G, Villeneuve N, Lacoste C, Abidi A, Cacciagli P, Altuzarra C, Roubertie A, Afenjar A, Renaldo-Robin F, Isidor B, Gautier A, Husson M, Cances C, Metreau J, Laroche C, Chouchane M, Ville D, Marignier S, Rougeot C, Lebrun M, de Saint Martin A, Perez A, Riquet A, Badens C, Missirian C, Philip N, Chabrol B, Villard L, Milh M. Epileptic patients with de novo STXBP1 mutations: Key clinical features based on 24 cases. Epilepsia. 2015 Dec;56(12):1931-40. doi: 10.1111/epi.13214. Epub 2015 Oct 29.

    PubMed 26514728

  • Stamberger H, Weckhuysen S, De Jonghe P. STXBP1 as a therapeutic target for epileptic encephalopathy. Expert Opin Ther Targets. 2017 Nov;21(11):1027-1036. doi: 10.1080/14728222.2017.1386175. Epub 2017 Oct 5.

    PubMed 28971703

  • Kovacevic J, Maroteaux G, Schut D, Loos M, Dubey M, Pitsch J, Remmelink E, Koopmans B, Crowley J, Cornelisse LN, Sullivan PF, Schoch S, Toonen RF, Stiedl O, Verhage M. Protein instability, haploinsufficiency, and cortical hyper-excitability underlie STXBP1 encephalopathy. Brain. 2018 May 1;141(5):1350-1374. doi: 10.1093/brain/awy046.

    PubMed 29538625

  • Patzke C, Han Y, Covy J, Yi F, Maxeiner S, Wernig M, Sudhof TC. Analysis of conditional heterozygous STXBP1 mutations in human neurons. J Clin Invest. 2015 Sep;125(9):3560-71. doi: 10.1172/JCI78612. Epub 2015 Aug 17.

    PubMed 26280581

  • Yamashita S, Chiyonobu T, Yoshida M, Maeda H, Zuiki M, Kidowaki S, Isoda K, Morimoto M, Kato M, Saitsu H, Matsumoto N, Nakahata T, Saito MK, Hosoi H. Mislocalization of syntaxin-1 and impaired neurite growth observed in a human iPSC model for STXBP1-related epileptic encephalopathy. Epilepsia. 2016 Apr;57(4):e81-6. doi: 10.1111/epi.13338. Epub 2016 Feb 25.

    PubMed 26918652

  • Martin S, Papadopulos A, Tomatis VM, Sierecki E, Malintan NT, Gormal RS, Giles N, Johnston WA, Alexandrov K, Gambin Y, Collins BM, Meunier FA. Increased polyubiquitination and proteasomal degradation of a Munc18-1 disease-linked mutant causes temperature-sensitive defect in exocytosis. Cell Rep. 2014 Oct 9;9(1):206-218. doi: 10.1016/j.celrep.2014.08.059. Epub 2014 Oct 2.

    PubMed 25284778

  • Chai YJ, Sierecki E, Tomatis VM, Gormal RS, Giles N, Morrow IC, Xia D, Gotz J, Parton RG, Collins BM, Gambin Y, Meunier FA. Munc18-1 is a molecular chaperone for alpha-synuclein, controlling its self-replicating aggregation. J Cell Biol. 2016 Sep 12;214(6):705-18. doi: 10.1083/jcb.201512016. Epub 2016 Sep 5.

    PubMed 27597756

  • Ito S, Hayashi H, Sugiura T, Ito K, Ueda H, Togawa T, Endo T, Tanikawa K, Kage M, Kusuhara H, Saitoh S. Effects of 4-phenylbutyrate therapy in a preterm infant with cholestasis and liver fibrosis. Pediatr Int. 2016 Jun;58(6):506-509. doi: 10.1111/ped.12839. Epub 2016 Feb 4.

    PubMed 26841694

  • Hasegawa Y, Hayashi H, Naoi S, Kondou H, Bessho K, Igarashi K, Hanada K, Nakao K, Kimura T, Konishi A, Nagasaka H, Miyoshi Y, Ozono K, Kusuhara H. Intractable itch relieved by 4-phenylbutyrate therapy in patients with progressive familial intrahepatic cholestasis type 1. Orphanet J Rare Dis. 2014 Jul 15;9:89. doi: 10.1186/1750-1172-9-89.

    PubMed 25022842

  • Naoi S, Hayashi H, Inoue T, Tanikawa K, Igarashi K, Nagasaka H, Kage M, Takikawa H, Sugiyama Y, Inui A, Nagai T, Kusuhara H. Improved liver function and relieved pruritus after 4-phenylbutyrate therapy in a patient with progressive familial intrahepatic cholestasis type 2. J Pediatr. 2014 May;164(5):1219-1227.e3. doi: 10.1016/j.jpeds.2013.12.032. Epub 2014 Feb 13.

    PubMed 24530123

  • Gonzales E, Grosse B, Cassio D, Davit-Spraul A, Fabre M, Jacquemin E. Successful mutation-specific chaperone therapy with 4-phenylbutyrate in a child with progressive familial intrahepatic cholestasis type 2. J Hepatol. 2012 Sep;57(3):695-8. doi: 10.1016/j.jhep.2012.04.017. Epub 2012 May 16.

    PubMed 22609309

  • Collins AF, Pearson HA, Giardina P, McDonagh KT, Brusilow SW, Dover GJ. Oral sodium phenylbutyrate therapy in homozygous beta thalassemia: a clinical trial. Blood. 1995 Jan 1;85(1):43-9.

    PubMed 7528572

Questions about this trial

What is this clinical trial studying?

A Early Phase 1 study testing Glycerol Phenylbutyrate 1100 MG/ML [Ravicti] in people with STXBP1 Encephalopathy With Epilepsy, SLC6A1 Neurodevelopmental Disorder and Developmental and Epileptic Encephalopathy, run by Weill Medical College of Cornell University at 2 sites in United States.

The full registered description is in the About this study section and the official record.

Who may be eligible to take part?

The sponsor lists 10 inclusion and 34 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.

Is this clinical trial currently recruiting?

The record says: under way, not looking for participants, as of the sponsor's last update on 22 Jan 2026. Status can change between updates, so confirm with the study contact before making plans.

Where is the study taking place?

The record lists 2 sites in United States. Whether a site is taking part right now should be confirmed with that site. See every site.

What are the possible benefits and risks?

They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.

What does this phase mean?

Early Phase 1 (sometimes called Phase 0) studies give a very small amount of a treatment to a few people, mainly to see how the body handles it.

Not every study follows the same path, and some studies (observational studies, device studies) have no phase.

Are results available for this study?

This study is still under way. Results are not available in the source record yet.

How can a doctor refer a patient or contact the research team?

The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.

What does the primary outcome measure?

Short Term Adverse events (i.e., safety) (time frame: 20 weeks). The study lists 3 primary outcomes in all. It is what the study was designed to measure, not a finding.

Where can I read the original study information?

On the ClinicalTrials.gov record for NCT04937062, which also lists 35 linked publications.

Does a listing mean the treatment is approved or proven to work?

No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.

How often is this information updated?

AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 22 Jan 2026.

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