An Efficacy and Safety Study of Clemizole HCl in Patients With Lennox-Gastaut Syndrome

NCT05066217 | Recruiting Phase 3 DMC FDA Drug

• 1 other identifier: EPX-100-003
• Study Type: interventional
• Target: 260
• Locations: 8 countries
• Sites: 61

Brief Summary

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

Conditions

Lennox Gastaut Syndrome

Keywords

Lennox Gastaut Syndrome; Lennox-Gastaut Syndrome; LGS; Clemizole HCl; Seizure

Outcome Measures

Primary Outcomes (1)

• Percent Change in CMMS-28

  Percent change in CMMS-28 from the Baseline Period through the end of the DB Period

  From Baseline Period up to 16 weeks

Secondary Outcomes (10)

• Proportion of Participants with ≥50% Reduction in CMMS-28

  From Baseline Period up to 16 weeks

• Percent Change in CMMS-28 Seizure-free Days

  From Baseline Period up to 16 weeks

• Clinical Global Impression of Change (CGI-C) Score

  Week 16

• Caregiver Global Impression of Change (CaGI-C) Score

  Week 16

• Caregiver Global Impression of Change in Seizure Intensity/Duration (CaGI-CSID) Score

  Week 16

Study Arms (3)

Placebo

PLACEBO COMPARATOR

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

Drug: Placebo

Double-blind clemizole HCl

EXPERIMENTAL

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

Drug: Clemizole HCl

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

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.

Placebo

Eligibility Criteria

• Age: 2 Years - 55 Years
• Sex: all
• Healthy Volunteers: No
• Age Groups: Child (0-17), Adult (18-64)

You may qualify if:

• Males or females, ages ≥2 to ≤55 years, at the time of Screening.
• Participant/parent/legal authorized representative (LAR) willing and able to give written informed consent/assent.
• Diagnosis of LGS, including:
• Evidence of at least one type of countable major motor seizure.
• History of electroencephalogram (EEG) consistent with LGS (abnormal background activity, and one of the following: 1) slow spike-wave discharges \[\<2.5 Hz\], or 2) paroxysmal fast activity during sleep).
• Abnormal cognitive development.
• Onset of seizures at 11 years of age or younger.

You may not qualify if:

• Known sensitivity, allergy, or previous exposure to clemizole HCl.
• Known history of long QT syndrome or any significant history of a serious abnormality of the electrocardiogram (ECG) (e.g., recent myocardial infarction, clinically significant arrhythmia).
• Family history of sudden cardiac death, unexplained death, or death from a primary dysrhythmia potentially associated with QT prolongation in any family member.
• Seizures secondary to illicit drug or alcohol use, infection, neoplasm, demyelinating disease, degenerative neurological disease, or progressive central nervous system disease, metabolic illness, recent anoxic episode within the last 6 months requiring resuscitation, or progressive degenerative disease or any other condition, which in the opinion of the investigator, could affect seizure control.
• Epilepsy surgery planned during the study or epilepsy surgery within 6 months prior to Screening.
• Concomitant use of fenfluramine.
• Prior or concomitant use of lorcaserin.

Sponsors & Collaborators

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

Study Sites (61)

Arkansas Children's Hospital

Little Rock, Arkansas, 72202, United States

ACTIVE NOT RECRUITING

UC Irvine Medical Center

Orange, California, 92868, United States

ACTIVE NOT RECRUITING

University of Miami Miller School of Medicine

Miami, Florida, 33136, United States

RECRUITING

AdventHealth Innovation Tower

Orlando, Florida, 32804, United States

RECRUITING

Rare Disease Research

Orlando, Florida, 34746, United States

SUSPENDED

Pediatric Neurology and Epilepsy Specialists

Winter Park, Florida, 32789, United States

ACTIVE NOT RECRUITING

Re:Cognition Health

Chicago, Illinois, 60611, United States

RECRUITING

Norton Children's Medical Center

Louisville, Kentucky, 40202, United States

RECRUITING

Henry Ford Hospital

Detroit, Michigan, 48202, United States

ACTIVE NOT RECRUITING

Minnesota Epilepsy Group, P.A.

Roseville, Minnesota, 55102, United States

RECRUITING

Children's Nebraska

Omaha, Nebraska, 68114, United States

RECRUITING

Tekton Research

Marlboro, New Jersey, 07746, United States

RECRUITING

NYU Comprehensive Epilepsy Center - BRANY - PPDS

New York, New York, 10016-4852, United States

RECRUITING

Weill Cornell Medicine/New York Presbyterian Hospital

New York, New York, 10021, United States

RECRUITING

Atrium Health STRIVE Research

Charlotte, North Carolina, 28207, United States

RECRUITING

On-Site Clinical Solution

Charlotte, North Carolina, 28211, United States

RECRUITING

Duke University Medical Center

Durham, North Carolina, 27705, United States

RECRUITING

PPD Virtual-Science 37, Inc.

Morrisville, North Carolina, 27560, United States

RECRUITING

Children's Hospital of Philadelphia

Philadelphia, Pennsylvania, 19104, United States

RECRUITING

Children's Health Specialty Center

Dallas, Texas, 75235, United States

RECRUITING

UTHealth Houston

Houston, Texas, 77030, United States

RECRUITING

Clinical Neurosciences Center

Salt Lake City, Utah, 84132, United States

RECRUITING

Peking University First Hospital - Changqiao Campus

Beijing, 100034, China

RECRUITING

Peking University First Hospital - Daxing Campus

Beijing, 100034, China

RECRUITING

Beijing Children's Hospital, Capital Medical University - PIN

Beijing, 100045, China

RECRUITING

The First Hospital of Jilin University

Changchun, 130021, China

RECRUITING

Hunan Children's Hospital

Changsha, 410007, China

RECRUITING

West China Second University Hospital, Sichuan University - Huaxi Campus

Chengdu, 610041, China

RECRUITING

Chengdu Women's and Children's Central Hospital

Chengdu, 610073, China

RECRUITING

Children's Hospital of Chongqing Medical University

Chongqing, 400014, China

RECRUITING

The Second Affiliated Hospital of Guangzhou Medical University

Guangzhou, 510260, China

RECRUITING

The Affiliated Hospital of Guizhou Medical University

Guiyang, 550004, China

RECRUITING

Qilu Hospital of Shandong University

Jinan, 250012, China

RECRUITING

Jiangxi Provincial Children's Hospital

Nanchang, 330006, China

RECRUITING

Shenzhen Children's Hospital

Shenzhen, 518000, China

RECRUITING

Wuhan Children's Hospital

Wuhan, 430015, China

RECRUITING

The Second Affiliated Hospital of Xi'an Jiaotong University

Xi'an, 710004, China

RECRUITING

Xuzhou Children's Hospital

Xuzhou, 221006, China

RECRUITING

Yashoda Hospitals Hitec City

Hyderabad, Andhra Pradesh, 500081, India

RECRUITING

Nizams Institute of Medical Sciences

Hyderabad, Andhra Pradesh, 500082, India

RECRUITING

Saachi Children Hospital

Surat, Gujarat, 395002, India

RECRUITING

IRCCS Azienda Ospedaliera Metropolitan

Genoa, Liguria, 16132, Italy

RECRUITING

IRCCS Istituto Neurologico Mediterraneo Neuromed

Pozzilli, Molise, 86077, Italy

RECRUITING

Azienda Ospedaliera Universitaria Renato Dulbecco - AO Mater Domini

Catanzaro, 88100, Italy

RECRUITING

Azienda Ospedaliero Universitaria A Meyer

Florence, 50139, Italy

RECRUITING

Fondazione IRCCS Istituto Neurologico Carlo Besta

Milan, 20133, Italy

RECRUITING

Centrum Medyczne Plejady Magdalena Celinska

Krakow, Lesser Poland Voivodeship, 30-363, Poland

RECRUITING

Neurosphera

Warsaw, Masovian Voivodeship, 02-829, Poland

RECRUITING

Centrul National Clinic De Recuperare Neuropsihomotorie Copii Robanescu-Padure

Bucharest, 041408, Romania

RECRUITING

Emergency University Hospital

Bucharest, 050098, Romania

RECRUITING

Sf. Maria Children Emergency Clinical Hospital Iasi

Iași, 700309, Romania

RECRUITING

Childrens University Hospital

Belgrade, 11000, Serbia

RECRUITING

Mother and Child Health Care Institute of Serbia Dr Vukan Cupic

Belgrade, 11000, Serbia

RECRUITING

University Clinical Center Nis

Niš, 18 000, Serbia

RECRUITING

Children and Youth Health Care Institute of Vojvodina

Novi Sad, 21000, Serbia

RECRUITING

Hospital de La Santa Creu i Sant Pau

Barcelona, 08025, Spain

RECRUITING

Hospital Universitario Vall d'Hebron - PPDS

Barcelona, 08035, Spain

RECRUITING

Hospital Infantil Universitario Niño Jesus - PIN

Madrid, 28009, Spain

RECRUITING

Hospital Regional Universitario de Malaga - Hospital General

Málaga, 29010, Spain

RECRUITING

Hospital Universitario de Navarra

Pamplona, 31008, Spain

RECRUITING

Centro de Neurologia Avanzada

Seville, 41013, Spain

RECRUITING

MeSH Terms

Conditions

Lennox Gastaut Syndrome; Seizures

Condition Hierarchy (Ancestors)

Epileptic Syndromes; Epilepsy; Brain Diseases; Central Nervous System Diseases; Nervous System Diseases; Genetic Diseases, Inborn; Congenital, Hereditary, and Neonatal Diseases and Abnormalities; Neurologic Manifestations; Signs and Symptoms; Pathological Conditions, Signs and Symptoms

Study Officials

• Amit Ray, MD

  Harmony Biosciences Management, Inc.

  STUDY DIRECTOR

Central Study Contacts

Juby Philip

CONTACT

(302) 559-4320; clinicaltrials@harmonybiosciences.com

Cindy Sandy

CONTACT

(317) 258-7262; 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: September 23, 2021
• First Posted: October 4, 2021
• Study Start: April 9, 2025
• Primary Completion (Estimated): November 1, 2026
• Study Completion (Estimated): November 1, 2029
• Last Updated: October 2, 2026

Record last verified: 2026-10

Data Sharing

• IPD Sharing: Will not share

Locations

US (22); PL (2); IT (5); SE (4); ES (6); CN (16); RO (3); IN (3)