A Study of EPX-100 (Clemizole Hydrochloride) in Participants With Dravet Syndrome

NCT04462770 | Recruiting Phase 3 DMC FDA Drug

• 2 other identifiers: EPX-100-0012024-518628-57-00
• Study Type: interventional
• Target: 150
• Locations: 8 countries
• Sites: 46

Brief Summary

This is a multicenter, Phase 3, randomized, double-blind, placebo-controlled study designed to evaluate the efficacy and safety of clemizole hydrochloride (EPX-100) as adjunctive therapy in children and adult participants with Dravet syndrome (DS).

Conditions

Dravet Syndrome

Keywords

Clemizole hydrochloride; Convulsive seizure; Pediatric epilepsy; Dravet syndrome

Outcome Measures

Primary Outcomes (2)

• Percent Change in Countable Motor Seizures Per 28 Days (CMS-28) in the Titration Plus Maintenance Periods Relative to Baseline

  Percent change in CMS-28 from the Baseline Period through the end of the DB period.

  From Baseline Period (Day 1) up to 16 weeks

• European Union: Percent Change in Countable Motor Seizures Per 28 Days in the Maintenance Period Relative to Baseline

  Percent change in CMS-28 from the Baseline Period through the end of the maintenance period.

  From maintenance period Baseline (Day 29) up to Day 85

Secondary Outcomes (12)

• Proportion of Participants with >=50% reduction in Countable Motor Seizures Per 28 Days in the Titration Plus Maintenance Periods Relative to Baseline

  From Baseline Period (Day 1) up to 16 weeks

• European Union: Proportion of Participants with >=50% reduction in Countable Motor Seizures Per 28 Days in the Maintenance Period Relative to Baseline

  From maintenance period Baseline (Day 29) up to Day 85

• Number of Countable Motor Seizure-free Days in the Titration Plus Maintenance Periods Relative to Baseline

  From Baseline Period (Day 1) up to 16 weeks

• European Union: Number of Countable Motor Seizure-free Days in the Maintenance Period Relative to Baseline

  From maintenance period Baseline (Day 29) up to Day 85

• Clinical Global Impression of Improvement - Clinician (CGII-C) Score

  Day 85

Study Arms (3)

Double-blind clemizole HCl

EXPERIMENTAL

Participants will receive their first dose of study drug following randomization.

Drug: Clemizole HCl

Placebo

PLACEBO COMPARATOR

Participants will receive their first dose of study drug following randomization.

Drug: Placebo

Open-label clemizole HCl

EXPERIMENTAL

Eligible participants who complete the DB Period will have the option to continue in the OLE Period, during which they will receive clemizole HCL for up to 3 years.

Drug: Clemizole HCl; Drug: Placebo

Interventions

Clemizole HCl DRUG

Clemizole HCl will be administered as an oral solution.

Also known as: EPX-100

Double-blind clemizole HCl; Open-label clemizole HCl

Placebo DRUG

Placebo will be administered as an oral solution.

Open-label clemizole HCl; Placebo

Eligibility Criteria

• Age: 2 Years+
• Sex: all
• Healthy Volunteers: No
• Age Groups: Child (0-17), Adult (18-64), Older Adult (65+)

You may qualify if:

• Male and female participants 2 years and older at time of consent.
• Participant or parent/legally authorized representative (LAR) willing and able to provide written informed consent, assent (if applicable) prior to initiation of any study related procedures.
• Clinical diagnosis of DS. Participants must have seizures which are not completely controlled by AEDs with the following criteria:
• Onset of seizures prior to 18 months of age,
• Normal development at onset,
• History of at least one type of countable motor seizure (CMS),
• Brain MRI without cortical malformation (not including mild atrophy associated with the natural progression of DS),
• Genetic mutation of the SCN1A gene must be documented.

You may not qualify if:

• Known sensitivity, allergy, or previous exposure to clemizole HCl.
• Exposure to any investigational drug or device \<90 days prior to screening or plans to participate in another drug or device trial at any time during the study.
• Seizures secondary to illicit drug (this includes concomitant use of tetrahydrocannabinol \[THC\] and nonprescription cannabidiol preparations) or alcohol use, infection, neoplasm, demyelinating disease, degenerative neurological disease, or central nervous system disease deemed progressive, metabolic illness, or progressive degenerative disease.
• Concurrent use of lorcaserin. Note: Prior use of lorcaserin is permitted if at least 30 days have passed since the last dose.
• Concurrent use of fenfluramine.
• Epilepsy surgery planned during the study or epilepsy surgery within 6 months prior to Screening.

Sponsors & Collaborators

• Epygenix: lead
• Harmony Biosciences Management, Inc.: collaborator

Study Sites (46)

Children's Hospital of Los Angeles

Los Angeles, California, 90027, United States

TERMINATED

University of California Irvine

Orange, California, 92868, United States

RECRUITING

UCSF Medical Center

San Francisco, California, 94158, United States

RECRUITING

Yale University School of Medicine

New Haven, Connecticut, 06510, United States

NOT YET RECRUITING

The Nemours Foundation

Wilmington, Delaware, 19803, United States

RECRUITING

Rare Disease Research FL

Kissimmee, Florida, 34746, United States

NOT YET RECRUITING

Pediatric Neurology and Epilepsy Specialists

Winter Park, Florida, 32789, United States

NOT YET RECRUITING

Clinical Integrative Research Center of Atlanta (CIRCA)

Atlanta, Georgia, 30328, United States

NOT YET RECRUITING

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

Chicago, Illinois, 60611, United States

WITHDRAWN

Norton Children's Research Institute

Louisville, Kentucky, 40202, United States

NOT YET RECRUITING

University of Michigan- Mott Children's Hospital

Ann Arbor, Michigan, 48109, United States

WITHDRAWN

Children's Nebraska

Omaha, Nebraska, 68114, United States

RECRUITING

Northeast Regional Epilepsy Group

Hackensack, New Jersey, 07601, United States

TERMINATED

Neurology Center for Epilepsy and Seizures

Marlboro, New Jersey, 07746, United States

ACTIVE NOT RECRUITING

Weill Cornell Medical Center

New York, New York, 10021, United States

RECRUITING

Northwell Health - Lenox Hill Hospital

New York, New York, 10075, United States

NOT YET RECRUITING

Duke University Health System

Durham, North Carolina, 27710, United States

NOT YET RECRUITING

Wake Forest Baptist Medical Center

Winston-Salem, North Carolina, 27157, United States

RECRUITING

Cincinnati Children's Hospital Medical Center

Cincinnati, Ohio, 45229, United States

RECRUITING

Cleveland Clinic

Cleveland, Ohio, 44195, United States

RECRUITING

Nationwide Children's Hospital

Columbus, Ohio, 43205, United States

WITHDRAWN

The Children's Hospital of Philadelphia

Philadelphia, Pennsylvania, 19104, United States

RECRUITING

Le Bonheur Children's Hospital

Memphis, Tennessee, 38103, United States

TERMINATED

Child Neurology Consultants of Austin

Austin, Texas, 78757, United States

RECRUITING

UT Southwestern/Children's Health

Dallas, Texas, 75207, United States

NOT YET RECRUITING

University of Utah

Salt Lake City, Utah, 84112, United States

RECRUITING

Seattle Children's Hospital

Seattle, Washington, 98105, United States

RECRUITING

UBC Children's Hospital Research Institute

Vancouver, British Columbia, V6H 3V1, Canada

RECRUITING

Children's Hospital of Eastern Ontario Research Institute Inc.

Ottawa, Ontario, K1H 8L1, Canada

RECRUITING

The Hospital for Sick Children

Toronto, Ontario, M5G 1X8, Canada

RECRUITING

Toronto Western Hospital, University Health Network

Toronto, Ontario, M5T 2S8, Canada

RECRUITING

Tbilisi State Medical University, Givi Zhvania Academic, Clinic of Pediatry

Tbilisi, 0159, Georgia

RECRUITING

Medi Club Georgia LLC

Tbilisi, 0160, Georgia

RECRUITING

Institute of Neurology and Neuropsychology LTD

Tbilisi, 0186, Georgia

RECRUITING

Semmelweis University

Budapest, 1085, Hungary

RECRUITING

University of Debrecen

Debrecen, 4032, Hungary

RECRUITING

University Clinical Center in Gdansk, Division of Developmental Neurology

Gdansk, Poland

NOT YET RECRUITING

Medical Centre Plejady

Krakow, 30-363, Poland

RECRUITING

Institute of Mother and Child

Warsaw, 01-211, Poland

RECRUITING

"Prof. Dr. Al. Obregia" Psychiatry Clinical Hospital

Bucharest, 041914, Romania

NOT YET RECRUITING

Hospital Infantil Universitario Niño Jesús

Madrid, Madrid Provincia, 28009, Spain

RECRUITING

Hospital de la Santa Creu i Sant Pau

Barcelona, 08025, Spain

RECRUITING

Cardiff and Vale University Health Board

Cardiff, CF14 4XW, United Kingdom

RECRUITING

Alder Hey Children's NHS Foundation Trust

Liverpool, L12 2AP, United Kingdom

NOT YET RECRUITING

Great Ormond Street Hospital For Children

London, WC1N 1EH, United Kingdom

RECRUITING

Sheffield Children's Hospital

Sheffield, S102TH, United Kingdom

RECRUITING

MeSH Terms

Conditions

Epilepsies, Myoclonic; Seizures

Condition Hierarchy (Ancestors)

Epilepsy, Generalized; Epilepsy; Brain Diseases; Central Nervous System Diseases; Nervous System Diseases; Epileptic Syndromes; Neurologic Manifestations; Signs and Symptoms; Pathological Conditions, Signs and Symptoms

Study Officials

• Amit Ray, MD

  Harmony Biosciences Management, Inc.

  STUDY DIRECTOR

Central Study Contacts

Krystle Rapchak

CONTACT

+1 (312) 847-1289; clinicaltrials@harmonybiosciences.com

Eric Bauer

CONTACT

clinicaltrials@harmonybiosciences.com

Study Design

• Study Type: interventional
• Phase: phase 3
• Allocation: RANDOMIZED
• Masking: TRIPLE
• Who Masked: PARTICIPANT, CARE PROVIDER, INVESTIGATOR
• Purpose: TREATMENT
• Intervention Model: PARALLEL
• Sponsor Type: INDUSTRY
• Responsible Party: SPONSOR

Model Details: Patients are randomized 1:1 to clemizole HCl (EPX-100) or placebo.

Study Record Dates

• First Submitted: July 6, 2020
• First Posted: July 8, 2020
• Study Start: September 15, 2020
• Primary Completion: April 1, 2026
• Study Completion (Estimated): May 1, 2029
• Last Updated: August 28, 2025

Record last verified: 2025-08

Data Sharing

• IPD Sharing: Will not share

Locations

RO (1); HU (2); US (27); CA (4); GE (3); GB (4); PL (3); ES (2)