SeizuresPhase 3NCT05219617
Investigate Efficacy and Safety of Carisbamate as Adjunctive Treatment for Seizures Associated With LGS in Children and Adults
A Phase 3 study testing Carisbamate in people with Seizures and Lennox Gastaut Syndrome, run by SK Life Science, Inc. at 71 sites in 16 countries.
Trial summary
The primary objective is to evaluate the efficacy of carisbamate (YKP509) as adjunctive treatment in reducing the number of drop seizures (tonic, atonic, and tonic-clonic) compared with placebo in pediatric and adult subjects (age 4-55 years) diagnosed with Lennox Gastaut Syndrome (LGS). Read more about this study
- Who is it for?
- Ages 4 to 55 years
- Conditions the study is for
- Seizures, Lennox Gastaut Syndrome
- What is being tested?
- Carisbamate
- Could I receive a placebo?
- Yes, some participants may receive a placebo
- How many people
- 252 participants
- Where
- 71 sitesin 16 countries
- Study dates
- 28 Apr 2022to Dec 2028
- Phase
- Phase 3
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 4 to 55 years
- All sexes
- No healthy volunteers
- Child, Adult
Who may be able to join
- Subject must have a documented history of Lennox-Gastaut syndrome by:
- Evidence of more than one type of seizure, of which at least one should be an atonic or tonic seizure
- History of an electroencephalogram (EEG) reporting diagnostic criteria for LGS (abnormal background activity accompanied by slow, spike and wave pattern <3.0 Hz)
- History of developmental delay
- Male or female subjects
- Subjects must be age 4-55 years at the time of consent/assent
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- Must have been <11 years old at the onset of LGS
- Subjects must have experienced at least 2 drop seizures with potential to fall (tonic, atonic, tonic-clonic) during the 4-week Baseline period preceding randomization (minimum of 4 drop seizures in the first two weeks and 4 in the last two weeks). Drop seizures are defined as a seizure involving the entire body, trunk, or head that led or could have led to a fall, injury, slumping in a chair, or hitting the subject's head on a surface. All drop seizure types must be countable (either as isolated seizures or as countable isolated seizures in a cluster).
- Subjects must have been receiving 1 to 4 concomitant anti-seizure medications (ASMs) at a stable dose for at least 4 weeks before Visit 1
- If not taking Epidiolex, subjects may take other approved cannabidiol or over the counter cannabidiol products. If taking cannabidiol other than Epidiolex, consult Medical Monitor to determine if it counts as a concomitant ASM.
- Dietary therapy and any CNS stimulator settings must be stable for 4 weeks prior to baseline and maintain stable regimen throughout the study. The dietary therapy and CNS stimulators are not counted as an ASM.
- Parents or caregivers must be able to keep accurate seizure diaries
- Subject is either not of childbearing potential, defined as premenarchal, postmenopausal for at least 1 year or surgically sterile (bilateral tubal ligation, bilateral oophorectomy, or hysterectomy), if of childbearing potential, must comply with an acceptable method of birth control during the study, for at least 4 weeks prior to study entry and for 4 weeks following completion of the study, if able.
- Subject and/or caregiver(s)/legal representative must be willing and able to give informed assent/consent for participation in the study
- Subject and their caregiver must be willing and able (in the investigator's opinion) to comply with all study requirements
- History of COVID-19 vaccination is permitted
Who cannot join
- Etiology of subject's seizures is a progressive neurologic disease. Subjects with tuberous sclerosis will not be excluded from study participation, unless there is a progressive brain tumor
- Evidence of clinically significant disease (e.g., cardiac, respiratory, gastrointestinal, renal disease, hepatic disease) that in the opinion of the investigator(s) could affect the subject's safety or study conduct
- Subjects who were on adrenocorticotropic hormone (ACTH) therapy in the 6 months prior to baseline
- Subject on dietary therapy for less than 4 weeks prior to screening visit (Visit 1) or suffers from frequent stooling
- Current use of felbamate with less than 18 months of continuous exposure
- Concomitant use of vigabatrin: subjects who took vigabatrin in the past must be discontinued for at least 5 months before Visit 1 and must have documentation showing no evidence of a vigabatrin-associated clinically significant abnormality in an automated visual perimetry test, if able.
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- Subject who had a history of hypoxia which needed emergency resuscitation within 12 months prior to baseline
- Status epilepticus within 12 weeks prior to Visit 1
- Any clinically significant illness (including COVID-19) in the 4 weeks prior to Visit 1, as evaluated by the Investigator
- Subject has clinically significant abnormal laboratory values, in the investigator's opinion, at Visit 1 or time of randomization (Visit 2)
- Subject has a history of any serious drug-induced hypersensitivity, e.g., toxic epidermal necrolysis, or Drug Reaction with Eosinophilia and Systemic Symptoms [DRESS]) or any drug-related rash requiring hospitalization
- Vagus Nerve Stimulation (VNS), Deep Brain Stimulation (DBS), Responsive Neurostimulator System (RNS) or other neurostimulation for epilepsy device implanted or activated <5 months year prior to enrollment. Stimulation parameters that have been stable for <4 weeks, or Battery life of unit not anticipated to extend for duration of trial.
- Subject is pregnant, may be pregnant, lactating or planning to be pregnant
- Any suicidal ideation with intent, with or without a plan within 6 months before Visit 2 (i.e., answering "Yes" to questions 4 or 5 in the Suicidal Ideation section of the age- specific Columbia-Suicide Severity Rating Scale (C-SSRS) in subjects aged 6 and above who are able to be evaluated
- Any suicidal behavior within 2 years before Visit 2 (i.e., answering YES to any question in the Suicidal behavior section of the age-specific Columbia-Suicide Severity Rating Scale (C-SSRS) in subjects aged 6 and above who are able to be evaluated.
- Evidence of significant active hepatic disease. Stable elevations of liver enzymes (alanine aminotransferase (ALT), and aspartate aminotransferase (AST)) due to concomitant medication(s) will be allowed if they are <3 x ULN
- Subject with total bilirubin [TBL] >2 x ULN (except for Gilbert's syndrome).
- Active viral hepatitis (B or C) as demonstrated by positive serology at the Screening visit (Visit 1)
- History of positive antibody/antigen test for human immunodeficiency virus (HIV)
- If taking Epidiolex, subject may not use other approved cannabidiol or over the counter cannabidiol products
- Scheduled for epilepsy-related surgery, VNS insertion, or any other stimulators/surgery during the projected course of the study
- Subject who has taken or used any investigational drug or device in the 4 weeks prior to the screening visit (Visit 1)
- Concomitant use of medications known to be strong inducers of cytochrome P450 (CYP3A) including, but not limited to: phenobarbital, phenytoin, carbamazepine, primidone, rifampin, troglitazone, St. John's Wort, efavirenz, nevirapine, glucocorticoids (other than topical usage), modafinil, pioglitazone, and rifabutin
- Evidence of cardiac disease, including unstable angina, myocardial infarction, within the past 2 years, uncontrolled heart failure, major arrhythmias, congenital short QT syndrome
- Subject with a short QTc interval (<340 msec) or long QTc interval (>460 msec) as confirmed by a repeated electrocardiogram (ECG)
- Benzodiazepine rescue administered on average more than once a week in the month before Visit 1
- Previous exposure to carisbamate or sensitivity/allergy to components of the oral suspension.
Trial locations and contacts
71 sites in 16 countries. Contact the study team or a site near you to ask about taking part.
71 sites in 16 countries
United States22 sites, 7 recruiting
- Completed
Austin Epilepsy Care Center - Clinic/Outpatient Facility
Austin, Texas, 78758
- Recruiting
Johns Hopkins Hospital
Baltimore, Maryland, 21287
Joon Yi Kang, MD
- Recruiting
Mid-Atlantic Epilepsy and Sleep Center
Bethesda, Maryland, 20817
Arkady Barber
Pavel Klein, MD
- Completed
Consultants in Epilepsy and Neurology PLLC
Boise, Idaho, 83702
- Completed
University of Missouri School of Medicine
Columbia, Missouri, 65211
- Completed
Neurology Consultants of Dallas, PA - Hospital
Dallas, Texas, 75231
- Recruiting
Duke University Clinical Research at Pickett Road
Durham, North Carolina, 27713
Muhammad Zafar, MD
- Recruiting
Northeast Regional Epilepsy Group
Hackensack, New Jersey, 07601
Eric Segal, MD
- Completed
University of Florida Health Science Center
Jacksonville, Florida, 32209
- Completed
Bluegrass Epilepsy Research, LLC
Lexington, Kentucky, 40504
- Completed
St. Peters Hospital
New Brunswick, New Jersey, 08901
- Completed
University Medical Center New Orleans
New Orleans, Louisiana, 70112
- Completed
AdventHealth
Orlando, Florida, 32803
- Recruiting
Stanford University Hospital
Palo Alto, California, 94305
Brenda Porter, MD
- Recruiting
Children's Hospital of Philadelphia
Philadelphia, Pennsylvania, 19104
Eric Marsh, MD
- Completed
Mayo Clinic
Rochester, Minnesota, 55905
- Recruiting
Pediatric Epilepsy and Neurology Specialists
Tampa, Florida, 33609
Jose Ferreira, MD
- Completed
University of South Florida
Tampa, Florida, 33620
- Completed
Montefiore
The Bronx, New York, 10467
- Completed
Axcess Medical Research
Wellington, Florida, 33414
- Completed
Virginia Epilepsy and Neurodevelopmental Clinic at WNC
Winchester, Virginia, 22601
- Completed
Wake Forest University - School of Medicine
Winston-Salem, North Carolina, 27101
Italy6 sites, 4 recruiting
- Completed
Azienda Ospedaliero Universitaria A Meyer - INCIPIT - PIN
Florence
- Recruiting
Istituto G Gaslini Ospedale Pediatrico IRCCS - INCIPIT - PIN
Genoa, Liguria
Pasquale Striano, MD
- Recruiting
ASST Fatebenefratelli Sacco - Ospedale dei Bambini Vittore Buzzi
Milan, Lombardy
Monica Lodi, MD
- Recruiting
Fondazione IRCCS Di Rilievo Nazionale Instituto
Milan, Lombardy
Elena Freri, MD
- Completed
ASST Santi Paolo E Carlo - Azienda Universitaria-Polo Universitaria - San Paolo
Milan
- Recruiting
Azienda Ospedaliera Universitaria Integrata Di Verona
Verona, Verona
Francesca Darra, MD
Colombia5 sites
- Withdrawn
Fundacion Hospital Universidad del Norte
Barranquilla
- Withdrawn
Fundacion Valle del Lili/Clinic - Outpatient
Cali
- Completed
CliniSalud del Sur S.A.S - Centro de Investigación
Envigado
- Completed
Hospital Pabloe Tubon Uribe
Medellín
- Completed
Institutio Neurologico de Colombia
Medellín
Serbia5 sites, 5 recruiting
- Recruiting
Childrens University Hospital
Belgrade, Belgrade
Dimitrije Nikolic, MD
- Recruiting
University Clinical Center of Serbia - PPDS
Belgrade
Dragoslav Sokic, MD
- Recruiting
University Clinical Center Kragujevac
Kragujevac
Aleksandar Gavrilovic, MD
- Recruiting
University Clinical Center Nis
Niš
Tatjana Tosic, MD
- Recruiting
Children and Youth Health Care Institute of Vojvodina
Novi Sad
Tatjana Redzek Mudrinic, MD
Marija Knezevic-Pogancev, MD
Australia4 sites, 2 recruiting
- Recruiting
Austin Hosptial
Heidelberg
Ingrid Scheffer, MD
- Recruiting
Alfred Health
Melbourne
Patrick Kwan
- Completed
Perth's Children Hospital
Nedlands
- Completed
Queensland Children's Hospital
South Brisbane
Israel4 sites
- Completed
Soroka University Medical Centre
Beersheba
- Completed
Hadassah Medical Center
Jerusalem, 91220
- Completed
Sheba Medical Center
Ramat Gan
- Completed
Tela Viv Sourlasky Medical Center
Tel Aviv, Tel Aviv
Portugal4 sites, 2 recruiting
- Completed
Hospital Garcia de Orta
Almada, Setúbal District
- Recruiting
Centro Hospitalar de Lisboa Norte, EPE
Lisbon, Lisbon District
Sofia Quintas, MD
- Completed
Centro Hospitalar de Lisboa Ocidental, EPE - Hospital Sao Francisco Xavier
Lisbon, Lisbon District
- Recruiting
Centro Hospitalar de Sao Joao, EPE
Porto, Porto District
Raquel Sousa, MD
Mexico3 sites, 3 recruiting
- Recruiting
Neurociencias Estudios Clinicos S.C.
Culiacán
Elmer Lopez Meza, MD
- Recruiting
Hospital Civil Fray Antonio Alcalde
Guadalajara, Jalisco
Hugo Ceja Moreno, MD
- Recruiting
Clinstile, S.A. de C.V.
Mexico City, 06700
Sandra Quinones, MD
South Korea3 sites, 2 recruiting
- Completed
Kyungpook National University Chilgok Hospital
Daegu
- Recruiting
Samsung Medical Center
Seoul
Jee Hun S. Lee, MD
- Recruiting
Seoul National University Hospital
Seoul
Byung Chan Lim, MD
Spain3 sites, 1 recruiting
- Completed
Hospital Sant Joan de Deu - PIN
Esplugues de Llobregat, Barcelona
- Completed
Hospital Infantil Universitario Niño Jesus - PIN
Madrid
- Recruiting
Hospital Ruber Internacional (Grupo Quironsalud)
Madrid
Antonio Gil-Nigel, MD
Taiwan3 sites, 2 recruiting
- Recruiting
National Taiwan University Hospital
Taipei
Wang-Tso Lee, MD
- Recruiting
Taipei Veterans General Hospital
Taipei
Ting-Rong Hsu, MD
- Completed
Chang Gung Memorial Hospital
Taoyuan
Argentina2 sites
- Completed
Hospital de Ninos de La Santisma Trinidad
Córdoba, Córdoba Province
- Completed
Resolution Psychopharmacology Research Institute
Mendoza, Mendoza Province
Germany2 sites, 2 recruiting
- Recruiting
Universitatsklinikum Erangen
Erlangen, Bavaria
Hajo Martinus Hamer, MD
- Recruiting
Kleinwachau Sächsisches Epilepsiezentrum
Radeberg, Saxony
Nils Holert, MD
Hungary2 sites, 1 recruiting
- Completed
Orszagos Mentalis, Ideggyogyaszati es Idegsebezeti Intezet
Budapest
- Recruiting
Semmelweis Egyetem Idegsebeszeti es Neurointervencios Klinika
Budapest
Anna Sakovics, MD
Poland2 sites, 1 recruiting
- Recruiting
Centrum Medyczne Plejady
Krakow
Marta Zolnowska, MD
- Completed
Szpital Kliniczny im.H.Swiecickiego Uniwersytetu Medycznego im.K.Marcinkowskiego w Poznaniu-Dluga1/2
Poznan, Greater Poland Voivodeship
About this study
Official title: A Randomized, Double-Blind, Placebo-Controlled Study to Investigate the Efficacy and Safety of Carisbamate (YKP509) as Adjunctive Treatment for Seizures Associated With Lennox-Gastaut Syndrome in Children and Adults, With Optional Open-Label Extension
The primary objective is to evaluate the efficacy of carisbamate (YKP509) as adjunctive treatment in reducing the number of drop seizures (tonic, atonic, and tonic-clonic) compared with placebo in pediatric and adult subjects (age 4-55 years) diagnosed with Lennox Gastaut Syndrome (LGS).
Read the detailed description
The secondary objectives are:
- To evaluate the efficacy of carisbamate (YKP509) as adjunctive treatment in reducing the total number of seizures compared with placebo in pediatric and adult subjects diagnosed with Lennox Gastaut Syndrome (LGS)
- Evaluate the safety, tolerability of carisbamate in the LGS population
- Evaluate steady-state pharmacokinetics of carisbamate in subjects with Lennox Gastaut.
- Conditions
- Seizures, Lennox Gastaut Syndrome
- Being tested
- Carisbamate
- Keywords
- Seizures, Lennox Gastaut Syndrome, Pediatrics, Adults
- Medical subject headings
- Seizures, Lennox Gastaut Syndrome
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
CarisbamateDrug
Adolescent subjects 12 to 18 years old will receive the same dose as adults. Subjects 4 to < 12 years old in the carisbamate 200 mg BID arm will receive 4 mg/kg BID (not to exceed 200 mg BID [or a total of 400 mg per day]).
Subjects 4 to < 12 years old in the carisbamate 300 mg BID arm will receive 5.5 mg/kg BID (not to exceed 300 mg BID [or a total of 600 mg per day]).
| Study group | Role | What they receive |
|---|---|---|
| Carisbamate 200 mg BID arm | Experimental | Age: 4 to <12y* Titration: 2 mg/kg BID Maintenance: 4 mg/kg BID
Age: ≥12 y Titration: 100 mg BID Maintenance: 200 mg BID Receives: Drug: Carisbamate |
| Carisbamate 300 mg BID arm | Experimental | Age: 4 to <12y* Titration: 2.75 mg/kg BID Maintenance: 5.5 mg/kg BID
Age: ≥12 y Titration: 150 mg BID Maintenance: 300 mg BID Receives: Drug: Carisbamate |
| Placebo matched to 200 mg BID arm | Placebo comparator | Age: 4 to <12y* Titration: Volume equivalent to 2 mg/kg BID Maintenance: Volume equivalent to 4 mg/kg BID
Age: ≥12 y Titration: Volume equivalent to 100 mg BID Maintenance: Volume equivalent to 200 mg BID Receives: Drug: Carisbamate |
| Placebo matched to 300 mg BID arm | Placebo comparator | Age: 4 to <12y* Titration: Volume equivalent to 2.75 mg/kg BID Maintenance: Volume equivalent to 5.5 mg/kg BID
Age: ≥12 y Titration: Volume equivalent to 150 mg BID Maintenance: Volume equivalent to 300 mg BID Receives: Drug: Carisbamate |
What is being measured
The primary outcome is the main question the study is designed to answer.
Primary outcome will be the percentage change from baseline in the total frequency (average per 28 days) of countable drop seizures with potential to fall (tonic, atonic, tonic-clonic) seizures during the double-blind treatment period.
Efficacy of Carisbamate YKP509
Measured: 3 years
Secondary outcomes (3)
The percentage of subjects with at least a 50% reduction from baseline in the total frequency of drop seizures (tonic, atonic, tonic-clonic) during the double-blind treatment period.
Efficacy of Carisbamate YKP509
Measured: 3 years
Percentage change from baseline in the frequency of all types of seizures (total seizures) during the double-blind treatment period.
Efficacy of Carisbamate YKP509
Measured: 3 years
Subject/Caregiver Global Impression of Change (S/CGIC) in overall condition score at the last visit.
Efficacy of Carisbamate YKP509- Scoring will be from 1 to 7 with 1 (very much improved) to 7 (very much worse)
Measured: 3 years
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted2 Feb 2022
- Study start28 Apr 2022
- Primary completionFeb 2027 (estimated)
- Study completionDec 2028 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for SeizuresStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase 3
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Model description
- This double-blind, randomized, placebo-controlled study will evaluate the efficacy of carisbamate 200 mg BID or the pediatric equivalent dose and 300 mg BID or the pediatric equivalent dose for the treatment of seizures associated with Lennox Gastaut syndrome in subjects 4 to 55 years of age.
- Masking
- Double blind
- Who is masked
- Participant, Care provider
- Enrolment
- 252 participants (estimated)
Sponsor and investigators
- Lead sponsor
- SK Life Science, Inc.
- Sponsor type
- Industry (pharma, biotech, devices)
- Responsible party
- Sponsor
- Investigators
- Marc Kamin, MD, Study director, SK Life Science, Inc.
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT05219617
- Sponsor's protocol ID
- YKP509C003
- Status last verified
- Nov 2026
- First submitted
- 6 Jan 2022
- Last updated
- 6 Nov 2026
- Results posted
- No
- Data monitoring committee
- Yes
- FDA-regulated drug
- Yes
- FDA-regulated device
- No
- Individual data sharing
- Undecided
Study at a glance
From the registry record, last updated by the sponsor on 6 Nov 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- A Randomized, Double-Blind, Placebo-Controlled Study to Investigate the Efficacy and Safety of Carisbamate (YKP509) as Adjunctive Treatment for Seizures Associated With Lennox-Gastaut Syndrome in Children and Adults, With Optional Open-Label Extension
- ClinicalTrials.gov ID
- NCT05219617
- Acronym / sponsor ID
- YKP509C003
- Conditions
- Seizures, Lennox Gastaut Syndrome
- Keywords
- Seizures, Lennox Gastaut Syndrome, Pediatrics, Adults
- Phase
- Phase 3
- Study type
- Interventional
- Recruitment status
- Recruiting
- Enrolment
- 252 participants (estimated)
- Lead sponsor
- SK Life Science, Inc.Industry (pharma, biotech, devices)
- Study start
- 28 Apr 2022 (actual)
- Primary completion
- Feb 2027 (estimated)
- Study completion
- Dec 2028 (estimated)
- First posted
- 2 Feb 2022 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
The primary objective is to evaluate the efficacy of carisbamate (YKP509) as adjunctive treatment in reducing the number of drop seizures (tonic, atonic, and tonic-clonic) compared with placebo in pediatric and adult subjects (age 4-55 years) diagnosed with Lennox Gastaut Syndrome (LGS).
Detailed description
The secondary objectives are:
- To evaluate the efficacy of carisbamate (YKP509) as adjunctive treatment in reducing the total number of seizures compared with placebo in pediatric and adult subjects diagnosed with Lennox Gastaut Syndrome (LGS)
- Evaluate the safety, tolerability of carisbamate in the LGS population
- Evaluate steady-state pharmacokinetics of carisbamate in subjects with Lennox Gastaut.
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Double blind (participant, care provider)
- Number of arms
- 4
- Model description
- This double-blind, randomized, placebo-controlled study will evaluate the efficacy of carisbamate 200 mg BID or the pediatric equivalent dose and 300 mg BID or the pediatric equivalent dose for the treatment of seizures associated with Lennox Gastaut syndrome in subjects 4 to 55 years of age.
| Arm | Type | Receives |
|---|---|---|
| Carisbamate 200 mg BID arm | Experimental | Drug: CarisbamateAge: 4 to <12y* Titration: 2 mg/kg BID Maintenance: 4 mg/kg BID Age: ≥12 y Titration: 100 mg BID Maintenance: 200 mg BID |
| Carisbamate 300 mg BID arm | Experimental | Drug: CarisbamateAge: 4 to <12y* Titration: 2.75 mg/kg BID Maintenance: 5.5 mg/kg BID Age: ≥12 y Titration: 150 mg BID Maintenance: 300 mg BID |
| Placebo matched to 200 mg BID arm | Placebo comparator | Drug: CarisbamateAge: 4 to <12y* Titration: Volume equivalent to 2 mg/kg BID Maintenance: Volume equivalent to 4 mg/kg BID Age: ≥12 y Titration: Volume equivalent to 100 mg BID Maintenance: Volume equivalent to 200 mg BID |
| Placebo matched to 300 mg BID arm | Placebo comparator | Drug: CarisbamateAge: 4 to <12y* Titration: Volume equivalent to 2.75 mg/kg BID Maintenance: Volume equivalent to 5.5 mg/kg BID Age: ≥12 y Titration: Volume equivalent to 150 mg BID Maintenance: Volume equivalent to 300 mg BID |
Who may qualify
- Ages
- 4 to 55 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Child, Adult
Key inclusion criteria (16 listed)
- Subject must have a documented history of Lennox-Gastaut syndrome by:
- Male or female subjects
- Subjects must be age 4-55 years at the time of consent/assent
- Must have been <11 years old at the onset of LGS
- Subjects must have experienced at least 2 drop seizures with potential to fall (tonic, atonic, tonic-clonic) during the 4-week Baseline period preceding randomization (minimum of 4 drop seizures in the first two weeks and 4 in the last two weeks). Drop seizures are defined as a seizure involving the entire body, trunk, or head that led or could have led to a fall, injury, slumping in a chair, or hitting the subject's head on a surface. All drop seizure types must be countable (either as isolated seizures or as countable isolated seizures in a cluster).
Key exclusion criteria (27 listed)
- Etiology of subject's seizures is a progressive neurologic disease. Subjects with tuberous sclerosis will not be excluded from study participation, unless there is a progressive brain tumor
- Evidence of clinically significant disease (e.g., cardiac, respiratory, gastrointestinal, renal disease, hepatic disease) that in the opinion of the investigator(s) could affect the subject's safety or study conduct
- Subjects who were on adrenocorticotropic hormone (ACTH) therapy in the 6 months prior to baseline
- Subject on dietary therapy for less than 4 weeks prior to screening visit (Visit 1) or suffers from frequent stooling
- Current use of felbamate with less than 18 months of continuous exposure
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| CarisbamateAdolescent subjects 12 to 18 years old will receive the same dose as adults. Subjects 4 to < 12 years old in the carisbamate 200 mg BID arm will receive 4 mg/kg BID (not to exceed 200 mg BID [or a total of 400 mg per day]). Subjects 4 to < 12 years old in the carisbamate 300 mg BID arm will receive 5.5 mg/kg BID (not to exceed 300 mg BID [or a total of 600 mg per day]). | Drug | Carisbamate 200 mg BID arm, Carisbamate 300 mg BID arm, Placebo matched to 200 mg BID arm, Placebo matched to 300 mg BID arm |
Primary outcome
Primary outcome will be the percentage change from baseline in the total frequency (average per 28 days) of countable drop seizures with potential to fall (tonic, atonic, tonic-clonic) seizures during the double-blind treatment period.
Time frame: 3 years
Efficacy of Carisbamate YKP509
3 secondary outcomes
The percentage of subjects with at least a 50% reduction from baseline in the total frequency of drop seizures (tonic, atonic, tonic-clonic) during the double-blind treatment period.
Time frame: 3 years
Percentage change from baseline in the frequency of all types of seizures (total seizures) during the double-blind treatment period.
Time frame: 3 years
Subject/Caregiver Global Impression of Change (S/CGIC) in overall condition score at the last visit.
Time frame: 3 years
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 6 Nov 2026.
- Individual participant dataSharing planned: Undecided
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
Marc Kamin, MD study director
SK Life Science, Inc.
71 sites in 16 countries: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Phase 3 study testing Carisbamate in people with Seizures and Lennox Gastaut Syndrome, run by SK Life Science, Inc. at 71 sites in 16 countries.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 16 inclusion and 27 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: looking for participants now, as of the sponsor's last update on 6 Nov 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 71 sites in United States, Italy, Colombia, Serbia, Australia and 11 more countries. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. Some participants in this study may receive a placebo. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
What does this phase mean?
Phase 3 studies compare the treatment with the current standard treatment or a placebo in a large group, to confirm how well it works and watch for side effects.
Not every study follows the same path, and some studies (observational studies, device studies) have no phase.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Barbara Remes (201-421-3810, bremes@sklsi.com), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Primary outcome will be the percentage change from baseline in the total frequency (average per 28 days) of countable drop seizures with potential to fall (tonic, atonic, tonic-clonic) seizures during the double-blind treatment period. (time frame: 3 years). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 6 Nov 2026.