Dravet SyndromePhase 1/2ENDEAVORNCT05419492
A Clinical Study to Evaluate the Safety and Efficacy of ETX101 in Infants and Children With SCN1A-Positive Dravet Syndrome
A Phase 1/2 study testing ETX101 in people with Dravet Syndrome, run by Encoded Therapeutics at 14 sites in 3 countries.
Trial summary
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 1A), aged ≥48 months to <18 years (Part 1B), and aged ≥6 to <48 months (Part 2). Read more about this study
- Who is it for?
- Ages 6 months to 17 years
- Conditions the study is for
- Dravet Syndrome
- What is being tested?
- ETX101
- Could I receive a placebo?
- Yes, some participants may receive a placebo
- How many people
- 113 participants
- Where
- 14 sitesin 3 countries
- Study dates
- 14 May 2024to Jun 2034
- Phase
- Phase 1/2
- 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 6 months to 17 years
- All sexes
- No healthy volunteers
- Child
Who may be able to join
- Participant must be aged between ≥6 months and <36 months in Part 1A, ≥48 months and <18 years in Part 1B, ≥6 months 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 1 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.
Who cannot join
- 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 has received sodium channel blockers during the Pre-Dosing Seizure Period.
- Participant has experienced seizure freedom for a period of 4 consecutive weeks within the 90-day period prior to informed consent.
- Participant has previously received gene or cell therapy.
- Participant is currently enrolled in a clinical trial or receiving an investigational therapy.
- Participant has clinically significant underlying liver disease.
Trial locations and contacts
14 sites in 3 countries. Contact the study team or a site near you to ask about taking part.
14 sites in 3 countries
United States11 sites, 11 recruiting
- Recruiting
Mott Children's Hospital
Ann Arbor, Michigan, 48109
Stephanie Rau, 734-232-8474, shatchew@med.umich.edu
- Recruiting
Colorado Children's Hospital
Aurora, Colorado, 80045
Kallie Dock, 720-777-5322, Kallie.dock@childrenscolorado.org
- Recruiting
Ann & Robert H. Lurie Children's Hospital of Chicago
Chicago, Illinois, 60611
Jazmine Ibarra, 312-227-0967, jazibarra@luriechildrens.org
Linda Laux
- Recruiting
Nationwide Children's Hospital
Columbus, Ohio, 43205
Kaitlyn Brown, 614-722-2286, Kaitlyn.brown2@nationwidechildrens.org
- Recruiting
Duke Children's Hospital & Health Center
Durham, North Carolina, 27705
Makenzi Buchanan, 919-613-1232, Makenzi.hayes@duke.edu
- Recruiting
Cook Children's Medical Center
Fort Worth, Texas, 76104
Neurology Epilepsy Research, (682) 885-2844, neuroepilepsyresearch@cookchildrens.org
Scott Perry
- Recruiting
Nicklaus Children's Hospital
Miami, Florida, 33155
Matt Lallas, 305-662-8330, Matt.Lallas@nicklaushealth.org
Dainelys Pena Rodriguez, 786-624-3547, Dainelys.PenaRodriguez@nicklaushealth.org
- Not yet recruiting
NYU Langone Health
New York, New York, 10016
Comprehensive Epilepsy Center, 646-558-0800, CECResearchStudyInfo@nyulangone.org
- Recruiting
Oregon Health and Science University (OHSU)
Portland, Oregon, 97239
Emily Stein, steine@ohsu.edu
- Recruiting
Mayo Clinic
Rochester, Minnesota, 55905
Bridget Neja, 507-266-9150, neja.bridget@mayo.edu
- Recruiting
UCSF Benioff Children's Hospitals
San Francisco, California, 94158
Adam Numis, MD, Adam.numis@ucsf.edu
Adam Numis
United Kingdom2 sites, 2 recruiting
- Recruiting
Queen Elizabeth Hospital
Glasgow, G51 4TF
Patricia Clark, 0141 232 7600, Patricia.Clark2@ggc.scot.nhs.uk
- Recruiting
Great Ormond Street Hospital
London, WC1N3JH
Helen Cross, MD, helen.cross10@nhs.net
Australia1 site, 1 recruiting
- Recruiting
The Royal Children's Hospital
Melbourne
Prof. Ingrid Scheffer
Dr. Katherine Howell, neurology.department@rch.org.au
About this study
Official title: ENDEAVOR: A Clinical Study to Evaluate the Safety and Efficacy of ETX101, an AAV9-Delivered Gene Therapy in Infants and Children With SCN1A-Positive Dravet Syndrome
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 1A), aged ≥48 months to <18 years (Part 1B), and aged ≥6 to <48 months (Part 2). Part 1A follows an open-label, dose-escalation design, Part 1B follows an open-label design, and Part 2 is a randomized, double-blind, sham delayed-treatment control study.
- Conditions
- Dravet Syndrome
- Being tested
- ETX101
- Keywords
- Dravet, SCN1A, DEE, developmental and epileptic encephalopathy, Dravet Syndrome, SCN1A-positive, SCN1A+
- Medical subject headings
- Epilepsies, Myoclonic, Generalized Epilepsy With Febrile Seizures Plus, Type 2
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
ETX101Drug
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.
| Study group | Role | What they receive |
|---|---|---|
| Part 1 (US Only) | Experimental | Part 1A will follow an open-label, rule-based, dose-escalation design and will evaluate up to 4 dose levels of ETX101. Part 1B will follow an open-label design and will evaluate 1 dose level of ETX101. Receives: Drug: ETX101 |
| Part 2 | Sham comparator | Part 2 will follow a double-blind (up through Week 52), randomized, sham delayed-treatment control design.
There will be 2 cohorts in Part 2. A single dose level of ETX101 will be evaluated in Part 2 and participants will be randomized 2:1 to study treatment or sham procedure with delayed treatment. Receives: Drug: ETX101 |
What is being measured
The primary outcome is the main question the study is designed to answer.
Percent change in monthly countable seizure frequency (MCSF) between the Pre-Dosing Seizure Period and the Post-Dosing Assessment Period.
Measured: Between the Pre-Dosing Seizure Period and the Post-Dosing Assessment Period (defined as Week 5 to Week 52).
Secondary outcomes (10)
Change from Baseline in Bayley-4 cognitive subdomain raw score at Week 52 (Key Secondary Endpoint for Part 2).
Measured: From Baseline to Week 52.
Change from Baseline in Vineland-3 subdomain GSVs at Week 52.
Measured: From Baseline to Week 52.
Change from Baseline in Bayley-4 subdomain GSVs at Week 52.
Measured: From Baseline to Week 52.
Proportion of participants achieving ≥ 75% reduction in MCSF between the Pre-Dosing Seizure Period and the Post-Dosing Assessment Period.
Measured: Between the Pre-Dosing Seizure Period and the Post-Dosing Assessment Period (defined as Week 5 to Week 52).
Proportion of participants achieving ≥ 50% reduction in MCSF between the Pre-Dosing Seizure Period and the Post-Dosing Assessment Period.
Measured: Between the Pre-Dosing Seizure Period and the Post-Dosing Assessment Period (defined as Week 5 to Week 52).
Change from Baseline in the Vineland-3 Adaptive Behavior Composite standard score at Week 52.
Measured: From Baseline to Week 52.
Change from Baseline in Vineland-3 subdomain raw scores at Week 52.
Measured: From Baseline to Week 52.
Change from Baseline in Bayley-4 subdomain raw scores (excluding cognitive subdomain) at Week 52.
Measured: From Baseline to Week 52.
Proportion of CGI-I responders, defined as participants with a CGI-I score of 1 (Very much improved) or 2 (Much improved), at Week 52.
Measured: From Baseline to Week 52.
Proportion of CGI-S responders, defined as participants who either have a CGI-S score of 1 (Normal, not at all ill) or demonstrate a ≥2 point improvement from Baseline, at Week 52.
Measured: From Baseline to Week 52.
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted15 Jun 2022
- Study start14 May 2024
- Primary completionJun 2028 (estimated)
- Study completionJun 2034 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Dravet SyndromeStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase 1/2
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Quadruple blind
- Who is masked
- Participant, Care provider, Investigator, Outcomes assessor
- Enrolment
- 113 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Encoded Therapeutics
- Sponsor type
- Industry (pharma, biotech, devices)
- Responsible party
- Sponsor
- Investigators
- Salvador Rico, M.D., Ph.D, Study director, Encoded Therapeutics
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT05419492
- Sponsor's protocol ID
- ETX-DS-002
- Acronym
- ENDEAVOR
- Status last verified
- Oct 2026
- First submitted
- 10 Jun 2022
- Last updated
- 23 Oct 2026
- Results posted
- No
- Data monitoring committee
- Yes
- FDA-regulated drug
- Yes
- FDA-regulated device
- No
- Individual data sharing
- No
Study at a glance
From the registry record, last updated by the sponsor on 23 Oct 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- ENDEAVOR: A Clinical Study to Evaluate the Safety and Efficacy of ETX101, an AAV9-Delivered Gene Therapy in Infants and Children With SCN1A-Positive Dravet Syndrome
- ClinicalTrials.gov ID
- NCT05419492
- Acronym / sponsor ID
- ENDEAVOR / ETX-DS-002
- Conditions
- Dravet Syndrome
- Keywords
- Dravet, SCN1A, DEE, developmental and epileptic encephalopathy, Dravet Syndrome, SCN1A-positive, SCN1A+
- Phase
- Phase 1/2
- Study type
- Interventional
- Recruitment status
- Recruiting
- Enrolment
- 113 participants (estimated)
- Lead sponsor
- Encoded TherapeuticsIndustry (pharma, biotech, devices)
- Study start
- 14 May 2024 (actual)
- Primary completion
- Jun 2028 (estimated)
- Study completion
- Jun 2034 (estimated)
- First posted
- 15 Jun 2022 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
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 1A), aged ≥48 months to <18 years (Part 1B), and aged ≥6 to <48 months (Part 2). Part 1A follows an open-label, dose-escalation design, Part 1B follows an open-label design, and Part 2 is a randomized, double-blind, sham delayed-treatment control study.
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Quadruple blind (participant, care provider, investigator, outcomes assessor)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Part 1 (US Only) | Experimental | Drug: ETX101Part 1A will follow an open-label, rule-based, dose-escalation design and will evaluate up to 4 dose levels of ETX101. Part 1B will follow an open-label design and will evaluate 1 dose level of ETX101. |
| Part 2 | Sham comparator | Drug: ETX101Part 2 will follow a double-blind (up through Week 52), randomized, sham delayed-treatment control design. There will be 2 cohorts in Part 2. A single dose level of ETX101 will be evaluated in Part 2 and participants will be randomized 2:1 to study treatment or sham procedure with delayed treatment. |
Who may qualify
- Ages
- 6 months to 17 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Child
Key inclusion criteria (5 listed)
- Participant must be aged between ≥6 months and <36 months in Part 1A, ≥48 months and <18 years in Part 1B, ≥6 months 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 1 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.
Key exclusion criteria (8 listed)
- 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 has received sodium channel blockers during the Pre-Dosing Seizure Period.
- Participant has experienced seizure freedom for a period of 4 consecutive weeks within the 90-day period prior to informed consent.
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| ETX101ETX101 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. | Drug | Part 1 (US Only), Part 2 |
Primary outcome
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).
10 secondary outcomes
Change from Baseline in Bayley-4 cognitive subdomain raw score at Week 52 (Key Secondary Endpoint for Part 2).
Time frame: From Baseline to Week 52.
Change from Baseline in Vineland-3 subdomain GSVs at Week 52.
Time frame: From Baseline to Week 52.
Change from Baseline in Bayley-4 subdomain GSVs at Week 52.
Time frame: From Baseline to Week 52.
Proportion of participants achieving ≥ 75% reduction in 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).
Proportion of participants achieving ≥ 50% reduction in 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).
Change from Baseline in the Vineland-3 Adaptive Behavior Composite standard score at Week 52.
Time frame: From Baseline to Week 52.
Change from Baseline in Vineland-3 subdomain raw scores at Week 52.
Time frame: From Baseline to Week 52.
Change from Baseline in Bayley-4 subdomain raw scores (excluding cognitive subdomain) at Week 52.
Time frame: From Baseline to Week 52.
Proportion of CGI-I responders, defined as participants with a CGI-I score of 1 (Very much improved) or 2 (Much improved), at Week 52.
Time frame: From Baseline to Week 52.
Proportion of CGI-S responders, defined as participants who either have a CGI-S score of 1 (Normal, not at all ill) or demonstrate a ≥2 point improvement from Baseline, at Week 52.
Time frame: From Baseline to Week 52.
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 23 Oct 2026.
- Individual participant dataSharing planned: No
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
Salvador Rico, M.D., Ph.D study director
Encoded Therapeutics
14 sites in 3 countries: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Phase 1/2 study testing ETX101 in people with Dravet Syndrome, run by Encoded Therapeutics at 14 sites in 3 countries.
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 5 inclusion and 8 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: looking for participants now, as of the sponsor's last update on 23 Oct 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 14 sites in United States, United Kingdom, Australia. 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. Some participants in this study may receive a placebo. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
What does this combined phase mean?
Phase 1 studies test a treatment in a small group of people for the first time or in a new way, mainly to check safety and find the right dose.
Phase 2 studies give the treatment to a larger group to see whether it has the intended effect and to keep checking safety.
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?
Contact Encoded Patient Advocacy (+1 (650) 398-4301, patientadvocacy@encoded.com), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
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).). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
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 23 Oct 2026.