Recruiting
Phase 3

Clemizole HCl

Sponsor:

Epygenix

Code:

NCT05066217

Conditions

Lennox Gastaut Syndrome

Eligibility Criteria

Sex: All

Age: 2 - 55

Healthy Volunteers: Not accepted

Interventions

Clemizole HCl

Placebo

Study Details

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

Study ID

NCT05066217

Start date

Apr 9, 2025

Status verified date

Aug, 2026

Completion date

Nov 1, 2029

Anticipated

Primary completion date

Nov 1, 2026

Anticipated

Eligibility Criteria

Eligibility Criteria

Sex: All

Age: 2 - 55

Healthy Volunteers: Not accepted

Key Inclusion Criteria:

1. Males or females, ages ≥2 to ≤55 years, at the time of Screening.
2. Participant/parent/legal authorized representative (LAR) willing and able to give written informed consent/assent.
3. 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.

Key Exclusion Criteria:

1. Known sensitivity, allergy, or previous exposure to clemizole HCl.
2. 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).
3. Family history of sudden cardiac death, unexplained death, or death from a primary dysrhythmia potentially associated with QT prolongation in any family member.
4. 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.
5. Epilepsy surgery planned during the study or epilepsy surgery within 6 months prior to Screening.
6. Concomitant use of fenfluramine.
7. Prior or concomitant use of lorcaserin.

Study Design

Enrollment

260 participants

Anticipated

Allocation

Randomized

Intervention Model

Parallel Assignment

Primary purpose

Treatment

Interventions and Outcome Measures

Arms

placebo comparator: Placebo

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

experimental: Double-blind clemizole HCl

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

experimental: Open-label clemizole HCl

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.

Interventions

Clemizole HCl

Clemizole HCl will be administered as an oral solution.

Placebo

Placebo will be administered as an oral solution.

Primary outcome measure

  • Percent Change in CMMS-28 [ Time Frame: From Baseline Period up to 16 weeks ]

Central Contacts and Locations

Locations

University of Miami Miller School of Medicine

Recruiting

Miami, Florida, United States, 33136

Contacts

Principal Investigator:

Kamil Detyniecki, MD

AdventHealth Innovation Tower

Recruiting

Orlando, Florida, United States, 32804

Principal Investigator:

Holly Skinner, DO

Re:Cognition Health

Recruiting

Chicago, Illinois, United States, 60611

Contacts

Principal Investigator:

Antonio Iglesias, MD

Norton Children's Medical Center

Recruiting

Louisville, Kentucky, United States, 40202

Contacts

Principal Investigator:

Jaime Shoup, MD

Minnesota Epilepsy Group, P.A.

Recruiting

Roseville, Minnesota, United States, 55102

Contacts

Principal Investigator:

Stephanie Ahrens, MD

Children's Nebraska

Recruiting

Omaha, Nebraska, United States, 68114

Contacts

Principal Investigator:

Sookyong Koh

Tekton Research

Recruiting

Marlboro, New Jersey, United States, 07746

Contacts

Principal Investigator:

Amor Mehta, MD

NYU Comprehensive Epilepsy Center - BRANY - PPDS

Recruiting

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

Principal Investigator:

Dana Price

Weill Cornell Medicine/New York Presbyterian Hospital

Recruiting

New York, New York, United States, 10021

Contacts

Principal Investigator:

Asim Shahid, MD

Atrium Health STRIVE Research

Recruiting

Charlotte, North Carolina, United States, 28207

Contacts

Principal Investigator:

Ravi Singh, MD

On-Site Clinical Solution

Recruiting

Charlotte, North Carolina, United States, 28211

Contacts

Principal Investigator:

Robert Nahouraii

Duke University Medical Center

Recruiting

Durham, North Carolina, United States, 27705

Contacts

Muhammad Zafar, MD

muhammad.zafar@duke.edu

Principal Investigator:

Muhammad Zafar, MD

PPD Virtual-Science 37, Inc.

Recruiting

Morrisville, North Carolina, United States, 27560

Contacts

Principal Investigator:

Antonio Iglesias, MD

Children's Hospital of Philadelphia

Recruiting

Philadelphia, Pennsylvania, United States, 19104

Principal Investigator:

Eric Marsh, MD

UTHealth Houston

Recruiting

Houston, Texas, United States, 77030

Contacts

Principal Investigator:

Mary Koenig, MD

Clinical Neurosciences Center

Recruiting

Salt Lake City, Utah, United States, 84132

Principal Investigator:

Angela Peters, MD

More Information

Sponsor

Epygenix

Last update posted

Aug 21, 2026

Last verified

Aug, 2026

Keywords

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

Trial information was received from ClinicalTrials.gov and was last updated on 2026-09-08. This information was provided to ClinicalTrials.gov by Epygenix on 2026-08-21.