A Clinical Trial of Elsunersen in Pediatric SCN2A-DEE to Assess Efficacy and Safety

NCT07019922 | Recruiting Phase 3 DMC FDA Drug

• 1 other identifier: PRAX-222-311
• Study Type: interventional
• Target: 50
• Locations: 1 country
• Sites: 2

Brief Summary

A Randomized, Multi-Center, Double-Blind, Sham-Procedure-Controlled Clinical Trial to Investigate the Efficacy and Safety of Elsunersen in Pediatric Participants with Early Onset SCN2A Developmental and Epileptic Encephalopathy

Conditions

Epileptic Encephalopathy; SCN2A Encephalopathy

Keywords

epilepsis; early onset scn2a; epileptic encephalopathy; scn2a; gain of function; seizure

Outcome Measures

Primary Outcomes (1)

• To assess the efficacy of elsunersen on seizure frequency in participants with early-onset SCN2A DEE

  Median percent change in monthly (28 days) motor seizure frequency from baseline to treatment after 24 weeks

  24 weeks

Secondary Outcomes (8)

• To assess secondary efficacy outcomes of elsunersen in participants with early-onset SCN2A DEE

  24 weeks

• To assess secondary efficacy outcomes of elsunersen in participants with early-onset SCN2A DEE

  24 weeks

• CGI-S change from baseline

  24 weeks

• CGI subdomain scores at each postdose time point

  24 weeks

• CgGI-S from baseline

  24 weeks

Study Arms (4)

Cohort 1 Arm 1: Double-Blind Treatment Period

EXPERIMENTAL

Double-blind treatment period elsunersen

Drug: 1mg elsunersen

Cohort 1 Arm 2: Double-Blind Treatment Period

SHAM COMPARATOR

Double-blind sham-procedure

Procedure: sham procedure

Cohort 2: Open-Label Treatment Period

EXPERIMENTAL

Open-label elsunersen

Drug: 1mg elsunersen

Cohort 3: Open-Label Treatment Period

EXPERIMENTAL

Open-label elsunersen

Drug: 0.5mg elsunersen

Interventions

1mg elsunersen DRUG

24 weeks every 4 weeks intrathecally

Cohort 1 Arm 1: Double-Blind Treatment Period; Cohort 2: Open-Label Treatment Period

sham procedure PROCEDURE

24 weeks of sham-procedure every 4 weeks

Cohort 1 Arm 2: Double-Blind Treatment Period

0.5mg elsunersen DRUG

24 weeks every 4 weeks intrathecally

Cohort 3: Open-Label Treatment Period

Eligibility Criteria

• Age: 1 Day - 18 Years
• Sex: all
• Healthy Volunteers: No
• Age Groups: Child (0-17), Adult (18-64)

You may qualify if:

• Has a documented Gain of Function SCN2A variant confirmed through genetic testing.
• Has onset of seizures prior to 3 months of age.
• Seizure frequency of 4 or more countable motor seizures per 28-day during the Baseline Observation Period.

You may not qualify if:

• Has any clinically significant or known pathogenic genetic variant other than in the SCN2A gene, or a genetic variant that may explain or contribute to the participant's epilepsy and/or developmental disorder.
• Has bone, spine (eg, kyphosis, scoliosis), bleeding, or other disorder.
• Has received any experimental or investigational drug, device, or other therapy within 30 days or 5 half-lives (whichever is longer) prior to Screening, including any prior use of gene therapy.
• Is currently pregnant or breastfeeding or is planning to become pregnant during the clinical trial.

Sponsors & Collaborators

• Praxis Precision Medicines: lead

Study Sites (2)

Praxis Research Site

San Diego, California, 92123, United States

RECRUITING

Praxis Research Site

Chicago, Illinois, 60612, United States

RECRUITING

MeSH Terms

Conditions

Epilepsy; Seizures

Condition Hierarchy (Ancestors)

Brain Diseases; Central Nervous System Diseases; Nervous System Diseases; Neurologic Manifestations; Signs and Symptoms; Pathological Conditions, Signs and Symptoms

Study Officials

• Medical Director

  Praxis Precision Medicines

  STUDY DIRECTOR

Central Study Contacts

Head of Pharmacovigilance

CONTACT

617-300-8460; clinicaltrials@praxismedicines.com

Study Design

• Study Type: interventional
• Phase: phase 3
• Allocation: RANDOMIZED
• Masking: QUADRUPLE
• Who Masked: PARTICIPANT, CARE PROVIDER, INVESTIGATOR, OUTCOMES ASSESSOR
• Masking Details: Cohort 1 is the only masked cohort (40 participants). Cohort 2 and Cohort 3 are both open-label and will have 5 participants each.
• Purpose: TREATMENT
• Intervention Model: SEQUENTIAL
• Sponsor Type: INDUSTRY
• Responsible Party: SPONSOR

Model Details: Specific milestones have to be met in Cohort 1 for enrollment to open in Cohort 2 and the same will apply to open Cohort 3.

Study Record Dates

• First Submitted: June 5, 2025
• First Posted: June 13, 2025
• Study Start: August 13, 2025
• Primary Completion (Estimated): June 1, 2026
• Study Completion (Estimated): December 1, 2028
• Last Updated: October 2, 2025

Record last verified: 2025-10

Locations

US (2)