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A Clinical Study to Evaluate the Safety and Efficacy of ETX101, an AAV9-Delivered Gene Therapy in Children With SCN1A-positive Dravet Syndrome

Phase 1
Recruiting
Conditions
Dravet Syndrome
Interventions
Registration Number
NCT06283212
Lead Sponsor
Encoded Therapeutics
Brief 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.

Detailed Description

Not available

Recruitment & Eligibility

Status
RECRUITING
Sex
All
Target Recruitment
4
Inclusion Criteria
  • 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
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 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.

Study & Design

Study Type
INTERVENTIONAL
Study Design
SEQUENTIAL
Arm && Interventions
GroupInterventionDescription
Cohort ZETX101Cohort Z will evaluate ETX101 dose level 3.
Cohort XETX101Cohort X will evaluate ETX101 dose level 1.
Cohort YETX101Cohort Y will evaluate ETX101 dose level 2.
Primary Outcome Measures
NameTimeMethod
Proportions of participants experiencing any treatment-emergent adverse events (AEs), serious adverse events (SAEs), related AEs, AEs with severity Grade ≥ 3, AEs resulting in study discontinuation, and AEs with fatal outcome.Day 1 through Study Completion, an average of 5 years
Change from baseline in the standard score of the Vineland Adaptive Behavior Scales - Third Edition Adaptive Behavior Composite at Week 52.Baseline to Week 52. Standard scores are normalized to a mean and SD of 100 and 15, respectively, and are not bounded by a range. Higher scores correspond to better outcomes.
Secondary Outcome Measures
NameTimeMethod
Percent change in monthly countable seizure frequency (MCSF) to Week 52, with countable seizures defined as generalized tonic-clonic/clonic, focal motor with clearly observable clinical signs, tonic bilateral, and atonic seizures.Between the 8-week baseline period and the 48-week post-dosing assessment period (defined as Week 5 to Week 52 following administration of ETX101)
Change from baseline in the raw score of the Bayley Scales of Infant and Toddler Development® 4th Edition receptive language sub-domain at Week 52.Baseline to Week 52. Raw scores range from 0 to 49 and higher scores correspond to better outcomes.

Trial Locations

Locations (3)

Sheffield Children's Hospital

🇬🇧

Sheffield, United Kingdom

Queen Elizabeth Hospital

🇬🇧

Glasgow, United Kingdom

Great Ormond Street Hospital

🇬🇧

London, United Kingdom

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