Dravet SyndromePhase 1/2UK OnlyNCT06283212
A Clinical Study to Evaluate the Safety and Efficacy of ETX101, an AAV9-Delivered Gene Therapy in Children With SCN1A-positive Dravet Syndrome
A Phase 1/2 study testing ETX101 in people with Dravet Syndrome, run by Encoded Therapeutics at 3 sites in United Kingdom.
Trial summary
EXPEDITION is a Phase 1/2 study in the UK to evaluate the safety and efficacy of ETX101 in participants with SCN1A-positive Dravet Syndrome aged 6 to < 48 months. The study follows and open-label, dose-escalation design. Read more about this study
- Who is it for?
- Ages 6 to 47 months
- Conditions the study is for
- Dravet Syndrome
- What is being tested?
- ETX101
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 5 participants
- Where
- 3 sitesUnited Kingdom
- Study dates
- 9 May 2024to Oct 2030
- Phase
- Phase 1/2
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 to 47 months
- All sexes
- No healthy volunteers
- Child
Who may be able to join
- Participant has a predicted loss of function pathogenic or likely pathogenic SCN1A variant
- Participant must have experienced their first seizure between the age of 3 and 15 months
- Participant must have a clinical diagnosis of Dravet syndrome or the treating clinician must have 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 is currently taking or has taken antiseizure medications (ASMs) at a therapeutic dose that are contraindicated in Dravet syndrome, including sodium channel blockers.
- 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
3 sites in 1 country.
United Kingdom3 sites
Queen Elizabeth Hospital
Glasgow, G51 4TF
Great Ormond Street Hospital
London, WC1N3JH
Sheffield Children's Hospital
Sheffield, S10 2TH
About this study
Official title: EXPEDITION: A Clinical Study to Evaluate the Safety and Efficacy of ETX101, an AAV9-Delivered Gene Therapy in Children With SCN1A-positive Dravet Syndrome
EXPEDITION is a Phase 1/2 study in the UK to evaluate the safety and efficacy of ETX101 in participants with SCN1A-positive Dravet Syndrome aged 6 to < 48 months. The study follows and open-label, dose-escalation design.
- Conditions
- Dravet Syndrome
- Being tested
- ETX101
- Medical subject headings
- Epilepsies, Myoclonic
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
ETX101Drug
ETX101 is composed of a non-replicating, recombinant adeno-associated viral serotype 9 (rAAV9) vector used to deliver a GABAergic regulatory element (reGABA) and an engineered transcription factor that increases transcription of the SCN1A gene (eTFSCN1A)
| Study group | Role | What they receive |
|---|---|---|
| Cohort A | Experimental | Cohort A will evaluate ETX101 dose level 1. Receives: Drug: ETX101 |
| Cohort B | Experimental | Cohort B will evaluate ETX101 dose level 2. Receives: Drug: ETX101 |
| Cohort C | Experimental | Cohort C will evaluate ETX101 dose level 3. Receives: Drug: ETX101 |
| Cohort D | Experimental | Cohort D will evaluate ETX101 dose level 4. 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
Measured: Baseline to Week 52
Change from Baseline in Vineland-3 subdomain GSVs at Week 52.
Measured: Baseline to Week 52.
Change from Baseline in Bayley-4 subdomain GSVs at Week 52.
Measured: 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: Baseline to Week 52.
Change from Baseline in Vineland-3 subdomain raw scores at Week 52.
Measured: Baseline to Week 52.
Change from Baseline in Bayley-4 subdomain raw scores (excluding cognitive subdomain) at Week 52.
Measured: 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: 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: 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 posted28 Feb 2024
- Study start9 May 2024
- Primary completionOct 2030 (estimated)
- Study completionOct 2030 (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
- Non-randomised
- Intervention model
- Sequential
- Masking
- None (open label)
- Enrolment
- 5 participants (actual)
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
- NCT06283212
- Sponsor's protocol ID
- ETX-DS-005
- Acronym
- UK Only
- Status last verified
- Jun 2026
- First submitted
- 22 Feb 2024
- Last updated
- 8 Jun 2026
- Results posted
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No