NCT05419492 · Encoded Therapeutics
A Clinical Study to Evaluate the Safety and Efficacy of ETX101 in Infants and Children With SCN1A-Positive Dravet Syndrome
(ENDEAVOR)
What this study is about
ENDEAVOR is a Phase 1/2, 2-part, conducted at multiple hospitals study to evaluate the safety and effectiveness of ETX101 in participants with SCN1A-positive Dravet syndrome aged ≥6 to \<36 months (Part 1) and aged ≥6 to \<48 months (Part 2).
View original scientific description
ENDEAVOR is a Phase 1/2, 2-part, multicenter study to evaluate the safety and efficacy of ETX101 in participants with SCN1A-positive Dravet syndrome aged ≥6 to \<36 months (Part 1) and aged ≥6 to \<48 months (Part 2). Part 1 follows an open-label, dose-escalation design, and Part 2 is a randomized, double-blind, sham delayed-treatment control, dose-selection study.
Interventions
DRUG
ETX101
ETX101 is a non-replicating, recombinant adeno-associated viral vector serotype 9 (rAAV9) comprising a GABAergic regulatory element (reGABA) and an engineered transcription factor that increases transcription of the SCN1A gene (eTFSCN1A). ETX101 is intended as a one-time intracerebroventricular (ICV) administration.
Primary outcome measures
Percent change in monthly countable seizure frequency (MCSF) between the Pre-Dosing Seizure Period and the Post-Dosing Assessment Period.
Time frame: Between the Pre-Dosing Seizure Period and the Post-Dosing Assessment Period (defined as Week 5 to Week 52).
Who can participate
This study lists these criteria on ClinicalTrials.gov. A study coordinator reviews eligibility during screening — this page does not determine whether you qualify.
Inclusion criteria
- Participant must be aged between ≥6 months and \<36 months in Part 1 and \<48 months in Part 2.
- Participant must have a predicted loss of function pathogenic or likely pathogenic SCN1A variant.
- Participant must have experienced their first seizure between the ages of 3 and 15 months.
- Participant must have a clinical diagnosis of Dravet syndrome or the treating clinician must have a high clinical suspicion of a diagnosis of Dravet syndrome.
- Participant is receiving at least one prophylactic antiseizure medication.
Exclusion criteria
- Participant has another genetic mutation or clinical comorbidity which could potentially confound the typical Dravet phenotype.
- Participant has a known central nervous system structural and/or vascular abnormality (indicated by an MRI or CT scan of the brain).
- Participant has an abnormality that may interfere with CSF distribution and/or has an existing ventriculoperitoneal shunt.
- Participant is currently taking or h
Where
- San Francisco, California
- Aurora, Colorado
- Miami, Florida
- Chicago, Illinois
- Boston, Massachusetts
- Ann Arbor, Michigan
- Rochester, Minnesota
- Durham, North Carolina
- Columbus, Ohio
- Portland, Oregon
- Fort Worth, Texas
Related conditions & keywords
Frequently asked questions
What is a clinical trial?
A clinical trial is a research study that tests new medical treatments, drugs, devices, or procedures to determine their safety and effectiveness. Trials are carefully designed and monitored to protect participants while advancing medical knowledge.
Is it safe to participate?
Clinical trials follow strict safety guidelines and ethical standards. Trials must be reviewed and approved, and participants are closely monitored by medical professionals throughout the study. You can withdraw at any time if you choose.
Will I be compensated?
Many clinical trials offer compensation for your time, travel expenses, and inconvenience. The specific compensation varies by study and will be discussed during the screening process. All study-related medical care is typically provided at no cost to participants.
Will I receive a placebo instead of treatment?
When effective treatment exists, participants typically receive either the standard treatment plus the study intervention, or the standard treatment plus placebo. You would not be denied effective care. Placebos are primarily used when no proven treatment is available, or in addition to standard care. Your trial consent form will clearly explain what treatments you may receive.
Can I leave a trial if I change my mind?
Absolutely. Participation in clinical trials is completely voluntary. You have the right to withdraw from the study at any time, for any reason, without penalty or loss of benefits to which you are otherwise entitled.
How long does a clinical trial last?
Trial duration varies widely depending on the study design and purpose. Some trials last just a few weeks, while others may continue for months or years. The study coordinator will provide specific timeline information during your screening call.
Data: ClinicalTrials.gov · synced Jul 9, 2026 · Source of record for eligibility and locations