Clinical trial • Phase III • Neurology

CLEMIZOLE HYDROCHLORIDE for Lennox-Gastaut syndrome

Phase III trial of CLEMIZOLE HYDROCHLORIDE for Lennox-Gastaut syndrome.

Overview

Trial Therapeutic Area
Neurology
Trial Disease
Lennox-Gastaut syndrome
Trial Stage
Phase III
Drug Modality
Small molecule
Paediatric Trial
Yes

Key dates

Initial CTIS Submission Date
22-12-2025
First CTIS Authorization Date
28-04-2026

Trial design

Randomised, open-label, placebo - matching placebo (matching placebo arm is specified; no dose or schedule for placebo stated).-controlled Phase III trial in Italy, Romania, Poland and others.

Randomised
Yes
Open Label
Yes
Comparator
Placebo - matching placebo (matching placebo arm is specified; no dose or schedule for placebo stated).
Single Multiple Or Escalation Dose Combined
Yes
Target Sample Size
162

Eligibility

Recruits 162 paediatric patients.

Pregnancy Exclusion
Pregnant women are excluded from this study
Vulnerable Population
The trial includes vulnerable populations (paediatric participants). Consent/assent handling: "Participant/parent/legal authorized representative (LAR) willing and able to give written informed consent/assent... If the participant is not qualified or able to provide written informed consent based on age, developmental stage, intellectual capacity, or other factors, parent/LAR must provide appropriate consent for study participation." Pediatric assent forms and parent/guardian ICFs are provided (multiple pediatric assent/ICF documents listed for different age groups and languages).

Inclusion criteria

  • {"criterion_text":"- 1. Males or females, ages ≥2 to ≤55 years, at the time of Screening."}
  • {"criterion_text":"- 10. Participant, parent, caregiver, or LAR is able and willing to maintain an accurate and complete daily seizure diary."}
  • {"criterion_text":"- 11. Willingness and ability to take study drug (suspension) as directed."}
  • {"criterion_text":"- 12. Sexually active WCBP must be using a medically acceptable method of birth control and have a negative serum or urine pregnancy test at the Screening (Visit 1) and Randomization (Visit 2). A WCBP is defined as a female who is biologically capable of becoming pregnant. Medically acceptable methods of birth control are listed in Appendix 11. In participants who are not sexually active, abstinence is an acceptable form of birth control and pregnancy testing will be conducted per protocol. Women who are of nonchildbearing potential (i.e., postmenopause or surgical menopause) must have this condition captured in their medical history. Pregnant women are excluded from this study"}
  • {"criterion_text":"- 13. Ketogenic diet, or a modified version of this diet, is allowed as long as the diet has been initiated and maintained at a steady state for at least 4 weeks prior to Screening and remains stable throughout the double-blind phase. Ketogenic diet does not count as an anti-seizure medication. During the OLE phase, once therapeutic doses have been fully established (Visit 16 onwards), diet can be changed if deemed necessary by the PI after discussion with the Medical Monitor."}
  • {"criterion_text":"- 2. Participant/parent/legal authorized representative (LAR) willing and able to give written informed consent/assent, after being properly informed of the nature and risks of the study and prior to engaging in any study-related procedures. If the participant is not qualified or able to provide written informed consent based on age, developmental stage, intellectual capacity, or other factors, parent/LAR must provide appropriate consent for study participation."}
  • {"criterion_text":"- 3. Diagnosis of LGS, including: • Evidence of at least one type of countable major motor seizure. • History of electroencephalogram consistent with LGS (abnormal background activity, slow spike-wave discharges [<2.5 Hz], or paroxysmal fast activity during sleep). • Abnormal cognitive development. • Onset of seizures at 11 years of age or younger."}
  • {"criterion_text":"- 4. Have a history of at least required number of countable seizures per month in the 2 months prior to Screening that must include tonic or tonic/atonic seizures."}
  • {"criterion_text":"- 5. Have at least required number of countable major motor seizures following the Screening Visit."}
  • {"criterion_text":"- 6. Approval for participation by the Independent Diagnostic Reviewer at The Epilepsy Consortium after review of the DERF and supporting documentation, such as the Participant Seizure and Medication Diary, EEGs, and neuroimaging. The Independent Reviewer from The Epilepsy Consortium will confirm LGS diagnosis and approve participation of each participant."}
  • {"criterion_text":"- 7. If participant has a surgically implanted vagal nerve stimulator: • The vagal nerve stimulator must have been placed ≥6 months prior to the Screening Visit. • The settings must have remained constant for 3 months prior to the Screening Visit and are expected to remain constant throughout the double-blind phase. During the OLE phase, once therapeutic doses have been fully established (Visit 16 onwards), settings can be changed if deemed necessary by the PI, after discussion with the Medical Monitor. • The battery must be expected to last for the duration of the double-blind phase."}
  • {"criterion_text":"- 8. Lack of seizure control despite appropriate trial of 1 or more antiseizure medications (ASMs) at therapeutic doses and for adequate duration of treatment per PI judgement."}
  • {"criterion_text":"- 9. Stable regimen of 4 or fewer ASMs ≥30 days prior to Visit 1 without a foreseeable dose adjustment for the duration of the study and in generally good health. Minor dose adjustments for tolerability may be permitted after discussion with the Medical Monitor."}

Exclusion criteria

  • {"criterion_text":"- 1. Has a known sensitivity, allergy, or previous exposure to clemizole HCl."}
  • {"criterion_text":"- 2. Has a QT interval corrected using Fridericia’s formula (QTcF) with a mean value of >450 msec (QTcF = QT/3√ RR) at Screening based on the mean of triplicate 12-lead electrocardiograms (ECGs)."}
  • {"criterion_text":"- 3. Has a known history of long QT syndrome or any significant history of a serious abnormality of the ECG (e.g., recent myocardial infarction, clinically significant arrhythmia)."}
  • {"criterion_text":"- 4. Has a family history of sudden cardiac death, unexplained death, or death from a primary dysrhythmia potentially associated with QT prolongation in any family member."}
  • {"criterion_text":"- 5. Seizures secondary to illicit drug or alcohol use, infection, neoplasm, demyelinating disease, degenerative neurological disease, or progressive CNS 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."}
  • {"criterion_text":"- 6. Changes in any chronic medications within the 30 days prior to Screening. All chronic concomitant medications must be relatively stable in dose for at least 30 days prior to the Screening Visit unless otherwise noted. Participants who have minor dose adjustments to manage tolerability may be permitted after discussion with the Medical Monitor."}
  • {"criterion_text":"- 7. Epilepsy surgery planned during the study or epilepsy surgery within 6 months prior to Screening."}
  • {"criterion_text":"- 8. Concomitant use of drugs that are moderate or strong inducers or inhibitors of cytochrome P450 (CYP) 3A4 is prohibited. Additionally, concomitant use of drugs with a narrow therapeutic index that are sensitive substrates for CYP3A4, CYP2C19, CYP2B6, CYP2D6, CYP2C8, and various transporters is prohibited."}
  • {"criterion_text":"- 9. Prior or concomitant use of lorcaserin."}
  • {"criterion_text":"- 11. Concomitant use of any prohibited drug listed in Protocol Appendix 1"}
  • {"criterion_text":"- 10. Concomitant use of fenfluramine. Participants with prior use of fenfluramine within the previous 3 months, or without proper documentation of an echocardiogram, at minimum 3 months following the last dose of fenfluramine, to ensure that the participant does not meet any criteria for drug-related (fenfluramine) cardiac valvular heart disease and/or drug-related pulmonary arterial hypertension as indicated by any of the following: • Mild or greater aortic regurgitation or moderate or greater mitral regurgitation. • Significant (greater than mild) tricuspid regurgitation. • Abnormally thickened cardiac valve and/or has restricted motion of the valve leaflets. • Elevated right heart/pulmonary artery pressure >35 mmHg."}
  • {"criterion_text":"- 12. A positive result on drug screen for tetrahydrocannabinol (THC) at Visit 1 (Screening)."}
  • {"criterion_text":"- 13. Concomitant use of THC/non-prescription cannabidiol preparations."}
  • {"criterion_text":"- 14. Does not agree to refraining from intake of grapefruits or grapefruit juice or Seville oranges."}
  • {"criterion_text":"- 15. 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."}
  • {"criterion_text":"- 16. Based on the judgment of the investigator, is unsuitable for the study for any reason, including but not limited to unstable or uncontrolled medical conditions (including psychiatric and neurological conditions) or a medical condition that might interfere with the conduct of the study, confound interpretation of study results, pose a health risk to the participant or compromise the integrity of the study."}
  • {"criterion_text":"- 17. Has a significant risk of committing suicide based on history, routine psychiatric examination, investigator’s judgment, or answering “yes” to Question 4 or 5 on the C‑SSRS (over the past 3 months prior to the first dose) or with any suicidal behavior (i.e., answering “yes” to the suicidal behavior questions) in the last 6 months before Screening."}
  • {"criterion_text":"- 18. Has moderate or severe hepatic impairment. Asymptomatic participants with mild hepatic impairment (elevated liver enzymes [AST or ALT] <3x ULN or elevated bilirubin <2x ULN) may be entered into the study after review and approval by the Medical Monitor after consideration of comorbidities and concomitant medications."}

Endpoints

Primary endpoints

  • {"endpoint_text":"- Percent change in CMMS-28 from the Baseline Period through the end of the DB Period (Titration plus Maintenance Phase)","definition_or_measurement_approach":"Percent change in CMMS-28 measured from the Baseline Period through the end of the Double-Blind Period (Titration plus Maintenance Phase) as stated in the primary endpoint description."}

Secondary endpoints

  • {"endpoint_text":"- Proportion of participants with ≥50% reduction in CMMS-28 from the Baseline Period through the end of the DB Period (Titration plus Maintenance Phase)","definition_or_measurement_approach":"Proportion of participants achieving ≥50% reduction in CMMS-28 from Baseline through end of DB Period as stated."}
  • {"endpoint_text":"- Percent change in CMMS-28 seizure-free days from the Baseline Period through the end of the DB Period (Titration plus Maintenance Phase)","definition_or_measurement_approach":"Percent change in CMMS-28 seizure-free days measured from Baseline through end of DB Period as stated."}
  • {"endpoint_text":"- CGI-C score at the end of the DB Period (Titration plus Maintenance Phase)","definition_or_measurement_approach":"Clinician Global Impression of Change (CGI-C) score at end of DB Period as stated."}
  • {"endpoint_text":"- CaGI-C score at the end of the DB Period (Titration plus Maintenance Phase)","definition_or_measurement_approach":"Caregiver Global Impression of Change (CaGI-C) score at end of DB Period as stated."}
  • {"endpoint_text":"- CaGI-CSID score at the end of the DB Period (Titration plus Maintenance Phase)","definition_or_measurement_approach":"Caregiver Global Impression - Clinician/Severity/Impact Domain (CaGI-CSID) score at end of DB Period as stated."}
  • {"endpoint_text":"- Change in QI-disability score from Baseline to the end of the DB Period (Titration plus Maintenance Phase)","definition_or_measurement_approach":"Change in QI-disability score from Baseline to end of DB Period as stated."}
  • {"endpoint_text":"- Percent change per 28 days in the number of seizure-free days (based on all seizure types) from the Baseline Period through the end of the DB Period (Titration plus Maintenance Phase)","definition_or_measurement_approach":"Percent change per 28 days in number of seizure-free days (all seizure types) from Baseline through end of DB Period as stated."}
  • {"endpoint_text":"- Percent change in CMMS-28 from the Baseline Period through the end of the DB Maintenance Phase only","definition_or_measurement_approach":"Percent change in CMMS-28 from Baseline through end of DB Maintenance Phase (maintenance period only) as stated."}
  • {"endpoint_text":"- Proportion of participants with ≥50% reduction in CMMS-28 from the Baseline Period through the end of the DB Maintenance Phase only","definition_or_measurement_approach":"Proportion of participants with ≥50% reduction in CMMS-28 from Baseline through end of DB Maintenance Phase only as stated."}
  • {"endpoint_text":"- Incidence of TEAEs","definition_or_measurement_approach":"Incidence of treatment-emergent adverse events (TEAEs) as stated."}

Recruitment

Registry Or Advocacy Recruitment
True, Epilepsy Study Consortium Inc.
Planned Sample Size
162
Recruitment Window Months
33
Consent Approach
Written informed consent must be provided by the participant, parent, caregiver, or legally authorized representative (LAR). Pediatric assent is required where applicable; pediatric assent and age-specific ICF documents are available (e.g. pediatric assent forms for ages 7-11, 11-14, 15-17 and adult/parent/LAR ICFs). Subject information and ICFs are provided in multiple country/language versions (examples in the document list: Italian, Hungarian, Romanian [eng/ron], Polish, Czech, Spanish, English).

Methods

  • Patient recruitment performed by Splash Clinical LLC (role: patient recruitment).
  • Participant reimbursement and concierge services (ClinCard) provided by Greenphire LLC (patient reimbursement, concierge, ClinCard).
  • Use of recruitment materials (brochures, posters, welcome booklets, patient brochures) provided per country/language as indicated by K1/K2 recruitment documents.

Geography

Total Number Of Sites
33
Total Number Of Participants
98

Italy

Earliest CTIS Part Ii Submission Date
03-04-2026
Latest Decision Or Authorization Date
28-04-2026
Processing Time Days
25
Number Of Sites
9
Number Of Participants
25

Sites

Site Name
Ospedale Pediatrico Bambino Gesu
Department Name
U.O.C. Neurologia dell'epilessia e disturbi del movimento
Contact Person Name
Nicola Specchio
Contact Person Email
nicola.specchio@opbg.net
Site Name
Fondazione Istituto Neurologico Nazionale Casimiro Mondino
Department Name
UO Neurofisiologia, Centro Epilessia
Contact Person Name
Elena Tartara
Contact Person Email
elena.tartara@mondino.it
Site Name
ASST Fatebenefratelli Sacco
Department Name
UOC Neurologia pediatrica
Contact Person Name
Pierangelo Veggiotti
Contact Person Email
pierangelo.veggiotti@unimi.it
Site Name
Azienda Ospedaliera Universitaria Meyer IRCCS
Department Name
Neuroscience and Medical Genetics Department
Contact Person Name
Renzo Guerrini
Contact Person Email
renzo.guerrini@meyer.it
Site Name
Istituto Neurologico Mediterraneo Neuromed S.p.A.
Department Name
Epylepsy study and treatment center
Contact Person Name
Alfredo D’Aniello
Contact Person Email
alfredodaniello@yahoo.com
Site Name
IRCCS Foundation Istituto Neurologico Carlo Besta
Department Name
U.O Neurologia
Contact Person Name
Giuseppe Didato
Site Name
IRCCS Istituto Giannina Gaslini
Department Name
Unit of Child Neusopchiatry
Contact Person Name
Maria Margherita Mancardi
Contact Person Email
margheritamancardi@gaslini.org
Site Name
Azienda Ospedaliero Universitaria Renato Dulbecco
Department Name
UOC Neurologia
Contact Person Name
Antonio Gambardella
Contact Person Email
agambardella@unicz.it
Site Name
IRCCS Azienda Ospedaliera Metropolitana
Department Name
U.O. Neurofisiopatologia
Contact Person Name
Flavio Villani
Contact Person Email
Flavio.Villani@hsanmartino.it

Romania

Earliest CTIS Part Ii Submission Date
16-04-2026
Latest Decision Or Authorization Date
04-05-2026
Processing Time Days
18
Number Of Sites
5
Number Of Participants
12

Sites

Site Name
Centrul National Clinic De Recuperare Neuropsihomotorie Copii Robanescu-Padure
Department Name
Sectia Neurologie Pediatrica
Contact Person Name
Madalina Cristina LEANCA
Contact Person Email
mada_mada332@yahoo.com
Site Name
Dr. Victor Gomoiu Clinical Children Hospital
Department Name
Sectia Clinica Neurologie Pediatrica
Contact Person Name
Raluca-Ioana TELEANU
Contact Person Email
raluca.teleanu@umfcd.ro
Site Name
Spitalul Clinic De Psihiatrie Prof.Dr.Alexandru Obregia
Department Name
Sectia Clinica Neurologie Pediatrica
Contact Person Name
Dana-Cristina CRAIU
Contact Person Email
dcraiu@yahoo.com
Site Name
Spitalul Clinic De Urgenta Pentru Copii Sfanta Maria Iasi
Department Name
Sectia Clinica Neurologie Pediatrica
Contact Person Name
Ioana GRIGORE
Contact Person Email
ioanag74@yahoo.com
Site Name
Spitalul Universitar De Urgenta Bucuresti
Department Name
Sectia Clinica Neurologie
Contact Person Name
Ioana-Raluca MINDRUTA
Contact Person Email
ioana.mindruta@umfcd.ro

Poland

Earliest CTIS Part Ii Submission Date
02-04-2026
Latest Decision Or Authorization Date
30-04-2026
Processing Time Days
28
Number Of Sites
6
Number Of Participants
12

Sites

Site Name
Neurosphera Sp. z o.o.
Department Name
N-A
Contact Person Name
Beata Zwolińska
Contact Person Email
beata.m.zwolinska@gmail
Site Name
Clinical Best Solutions Sp. z o.o. S.K.
Department Name
N-A
Contact Person Name
Jacek Gawłowicz
Contact Person Email
gawlowiczj@wp.pl
Site Name
Centrum Medyczne Saska Kępa
Department Name
N-A
Contact Person Name
Jolanta Strzelecka
Contact Person Email
jstrze@wp.pl
Site Name
Centrum Medyczne Plejady Magdalena Celinska Loewenhoff Michal Zolnowski sp.k.
Department Name
N-A
Contact Person Name
Marta Żołnowska
Contact Person Email
marta.zolnowska@gmail.com
Site Name
Uniwersytecki Szpital Kliniczny W Poznaniu
Department Name
Oddział Kliniczny Neurologii Dzieci i Młodzieży
Contact Person Name
Barbara Steinborn
Contact Person Email
bstein@ump.edu.pl
Site Name
Premium Clinic Wrocław CM
Department Name
N-A
Contact Person Name
Monika Służewska-Niedźwiedź

Czechia

Earliest CTIS Part Ii Submission Date
30-03-2026
Latest Decision Or Authorization Date
29-04-2026
Processing Time Days
30
Number Of Sites
2
Number Of Participants
12

Sites

Site Name
Fakultni Nemocnice Brno
Department Name
Klinika dětské neurologie
Contact Person Name
Ondřej Horák
Contact Person Email
horak.ondrej@fnbrno.cz
Site Name
Fakultni Nemocnice V Motole
Department Name
Neurologická klinika 2.LF UK a FN Motol
Contact Person Name
Jana Amlerová
Contact Person Email
jana.amlerova@fnmotol.cz

Hungary

Earliest CTIS Part Ii Submission Date
02-03-2026
Latest Decision Or Authorization Date
30-04-2026
Processing Time Days
59
Number Of Sites
4
Number Of Participants
12

Sites

Site Name
Semmelweis University
Department Name
Idegsebészeti es Neurointervenciós Klinika
Contact Person Name
Anna Kelemen
Contact Person Email
akelemen61@gmail.com
Site Name
Semmelweis University
Department Name
Gyermekgyógyászati Klinika
Contact Person Name
Márk Kristóf Farkas
Contact Person Email
kristofm.farkas@gmail.com
Site Name
University Of Debrecen
Department Name
Gyermekgyógyászati Intézet és Klinika
Contact Person Name
Mónika Bessenyei
Contact Person Email
besenyei.monika@med.unideb.hu
Site Name
University Of Pecs
Department Name
Gyermekgyógyászati Klinika
Contact Person Name
Katalin Hollódy
Contact Person Email
hollody.katalin@pte.hu

Spain

Earliest CTIS Part Ii Submission Date
31-03-2026
Latest Decision Or Authorization Date
11-05-2026
Processing Time Days
41
Number Of Sites
7
Number Of Participants
25

Sites

Site Name
Hospital Universitario De Navarra
Department Name
Neuropediatria
Contact Person Name
Sergio Aguilera Albesa
Site Name
Hospital Universitari Vall D Hebron
Department Name
Neurologia
Contact Person Name
Manuel Toledo Argany
Contact Person Email
manuel.toledo@vallhebron.cat
Site Name
Hospital Universitario Regional De Malaga
Department Name
Neurologia
Contact Person Name
Pedro Serrano
Contact Person Email
p.serrano.eecc@gmail.com
Site Name
Centro De Neurologia Avanzada S.L.P.
Department Name
Neurologia
Contact Person Name
Juan Jesus Rodriguez Uranga
Contact Person Email
uranganeuro@gmail.com
Site Name
Hospital Infantil Universitario Nino Jesus
Department Name
Neurologia pediátrica
Contact Person Name
Victor Soto Insuga
Contact Person Email
victorsotoinsuga@gmail.com
Site Name
Hospital De La Santa Creu I Sant Pau
Department Name
Neurologia
Contact Person Name
Alba Sierra-Marcos
Contact Person Email
asierram@santpau.cat
Site Name
Hospital Universitario Regional De Malaga
Department Name
Neurologia
Contact Person Name
Pedro Serrano
Contact Person Email
p.serrano.eecc@gmail.com

Sponsor

Primary sponsor

Full Name
Epygenix Therapeutics Inc.
Organisation Type
Pharmaceutical company
Country Of Registered Address
United States

Contract research organisations

Name
PPD Development LP
Name
PPD Global Central Labs
Name
Certara USA Inc.
Name
Everest Clinical Research Corporation
Name
Target Health LLC
Name
Fisher Clinical Services GmbH
Name
Bioagilytix Labs LLC
Name
Propharma Group LLC
Name
Eresearchtechnology Inc.
Responsibilities
ECG and eDiaries (eCOA)
Name
Splash Clinical LLC
Responsibilities
patient recruitment
Name
Greenphire LLC
Responsibilities
patient reimbursement, concierge, ClinCard
Name
Longboat Clinical Limited
Responsibilities
Site and Investigator trainings

Third parties

  • {"country":"United States","full_name":"Certara USA Inc.","duties_or_roles":"","organisation_type":"Pharmaceutical company"}
  • {"country":"Belgium","full_name":"PPD Global Central Labs","duties_or_roles":"","organisation_type":"Pharmaceutical company"}
  • {"country":"United States","full_name":"PPD Development LP","duties_or_roles":"","organisation_type":"Pharmaceutical company"}
  • {"country":"Canada","full_name":"Everest Clinical Research Corporation","duties_or_roles":"","organisation_type":"Pharmaceutical company"}
  • {"country":"United States","full_name":"Epilepsy Study Consortium Inc.","duties_or_roles":"review of Diagnostic eligibility review forms (DERF) for patient eligibility","organisation_type":"Pharmaceutical company"}
  • {"country":"United States","full_name":"Bioagilytix Labs LLC","duties_or_roles":"","organisation_type":"Pharmaceutical company"}
  • {"country":"United States","full_name":"Eresearchtechnology Inc.","duties_or_roles":"ECG and eDiaries (eCOA)","organisation_type":"Pharmaceutical company"}
  • {"country":"United States","full_name":"Splash Clinical LLC","duties_or_roles":"patient recruitment","organisation_type":"Non-Pharmaceutical company"}
  • {"country":"United States","full_name":"Greenphire LLC","duties_or_roles":"patient reimbursement, concierge, ClinCard","organisation_type":"Non-Pharmaceutical company"}
  • {"country":"Ireland","full_name":"Longboat Clinical Limited","duties_or_roles":"Site and Investigator trainings","organisation_type":"Non-Pharmaceutical company"}
  • {"country":"United States","full_name":"Propharma Group LLC","duties_or_roles":"","organisation_type":"Pharmaceutical company"}
  • {"country":"United States","full_name":"Target Health LLC","duties_or_roles":"","organisation_type":"Pharmaceutical company"}
  • {"country":"Germany","full_name":"Fisher Clinical Services GmbH","duties_or_roles":"","organisation_type":"Pharmaceutical company"}

Investigational products

Investigational Product Name
EPX-100 (Clemizole HCl)
Active Substance
CLEMIZOLE HYDROCHLORIDE
Modality
Small molecule
Routes Of Administration
ORAL
Route
ORAL
Investigational Product Name
Clemizole Hydrochloride placebo
Modality
Other

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