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Evaluating clemizole HCl for treating Lennox-Gastaut syndrome

Multicenter, Randomized, Double-blind, Placebo-controlled Trial of Clemizole HCl as Adjunctive Therapy in Patients With Lennox-Gastaut Syndrome

Phase 3 Interventional Epygenix · NCT05066217

This study is testing if clemizole HCl can help reduce seizures and improve the lives of people with Lennox-Gastaut syndrome, including children and adults.

Quick facts

PhasePhase 3
Study typeInterventional
Enrollment260 (estimated)
Ages2 Years to 55 Years
SexAll
SponsorEpygenix Industry-sponsored
Locations20 sites (Little Rock, Arkansas and 19 other locations)
Trial IDNCT05066217 on ClinicalTrials.gov

What this trial studies

This multicenter, Phase 3, randomized, double-blind, placebo-controlled study aims to assess the efficacy and safety of clemizole HCl as an adjunctive therapy for patients with Lennox-Gastaut syndrome (LGS). Participants, including children and adults aged 2 to 55, will undergo an observational period followed by a double-blind phase where they will receive either clemizole HCl or a placebo. The study will also include an optional open-label extension period for those who complete the initial phases. The goal is to determine if clemizole HCl can effectively reduce seizure frequency and improve overall patient outcomes.

Who should consider this trial

Good fit: Ideal candidates for this study are males and females aged 2 to 55 years diagnosed with Lennox-Gastaut syndrome who have experienced major motor seizures.

Not a fit: Patients with known sensitivity to clemizole HCl or significant cardiac history may not benefit from this study.

Why it matters

Potential benefit: If successful, this treatment could significantly reduce seizure frequency and improve the quality of life for patients with Lennox-Gastaut syndrome.

How similar studies have performed: Other studies have shown promise in using adjunctive therapies for Lennox-Gastaut syndrome, but the specific use of clemizole HCl is novel.

Eligibility criteria

Show full inclusion / exclusion criteria 
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.

Where this trial is running

Little Rock, Arkansas and 19 other locations

Study contacts

How to participate

  1. Review the eligibility criteria above with your treating physician.
  2. Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
  3. Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.
View on ClinicalTrials.gov → Find more trials like this →
Conditions Lennox Gastaut SyndromeLennox-Gastaut SyndromeLGSClemizole HClSeizure
Last reviewed 2026-06-13 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.