A Clinical Study to Evaluate the Safety and Efficacy of ETX101 in Infants and Children With SCN1A-Positive Dravet Syndrome

NCT ID: NCT05419492

Last Updated: 2025-06-12

Basic Information

• Recruitment Status: RECRUITING
• Clinical Phase: PHASE1/PHASE2
• Total Enrollment: 22 participants
• Study Classification: INTERVENTIONAL
• Study Start Date: 2024-05-14
• Study Completion Date: 2031-04-30

Brief 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 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.

Conditions

Dravet Syndrome

Study Design

• Allocation Method: RANDOMIZED
• Intervention Model: PARALLEL
• Primary Study Purpose: TREATMENT
• Blinding Strategy: QUADRUPLE

Study Groups

Part 1

Part 1 will follow an open-label, rule-based, dose-escalation design and will evaluate up to 4 dose levels of ETX101.

Group Type: EXPERIMENTAL

ETX101

Intervention Type: DRUG

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.

Part 2

Part 2 is a dose-selection study, which will follow a double-blind (up through Week 52), randomized, sham delayed-treatment control design.

There will be up to 3 cohorts in Part 2. If it is determined two dose levels of ETX101 will be evaluated in Part 2, participants will be randomized 1:1:1 to study treatment or sham procedure with delayed treatment. If Part 2 proceeds with a single dose level of ETX101, participants will be randomized 2:1 to study treatment or sham procedure with delayed treatment.

Group Type: SHAM_COMPARATOR

ETX101

Intervention Type: DRUG

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.

Interventions

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.

Intervention Type: DRUG

Eligibility Criteria

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 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, including under an expanded access and/or compassionate use program.
• Participant has clinically significant underlying liver disease.

• Minimum Eligible Age: 6 Months
• Maximum Eligible Age: 47 Months
• Eligible Sex: ALL
• Accepts Healthy Volunteers: No

Sponsors

Encoded Therapeutics

INDUSTRY

Sponsor Role: lead

Responsible Party

Responsibility Role: SPONSOR

Principal Investigators

Salvador Rico, M.D., Ph.D

Role: STUDY_DIRECTOR

Encoded Therapeutics

Locations

UCSF Benioff Children's Hospitals

San Francisco, California, United States

Site Status: RECRUITING

Ann & Robert H. Lurie Children's Hospital of Chicago

Chicago, Illinois, United States

Site Status: RECRUITING

Cook Children's Medical Center

Fort Worth, Texas, United States

Site Status: RECRUITING

Countries

United States

Central Contacts

Encoded Patient Advocacy

Role: CONTACT

patientadvocacy@encoded.com

+1 (650) 398-4301

Facility Contacts

Joseph Sullivan, MD

Role: primary

joseph.sullivan@ucsf.edu

Enrique Rojas

Role: primary

erojas@luriechildrens.org

312-227-2532

Dianna Grado, RN, CCRC

Role: primary

Dianna.Grado@cookchildrens.org

(682) 885-2844

Other Identifiers

ETX-DS-002

Identifier Type: -

Identifier Source: org_study_id