A Study to Investigate LP352 in Children and Adults With Developmental and Epileptic Encephalopathies (DEE)

A Phase 3, Randomized, Double-Blind, Placebo-Controlled, Multicenter Study to Investigate the Efficacy, Safety, and Tolerability of LP352 in the Treatment of Seizures in Children and Adults With Developmental and Epileptic Encephalopathies

This (DEEp OCEAN Study) is a double-blind, randomized, placebo-controlled, multicenter study to investigate the efficacy, safety, and tolerability of LP352 in the treatment of seizures in children and adults with DEE. The study consists of 3 main phases: Screening, Titration period, Maintenance period, followed by a Taper period and Follow-Up. The total duration of the study will be approximately 24 months.

Study Overview

• Status: Recruiting
• Conditions: Developmental and Epileptic Encephalopathy
• Intervention / Treatment: Drug: LP352; Drug: Placebo

• Study Type: Interventional
• Enrollment (Estimated): 320
• Phase: Phase 3

Contacts and Locations

• Study Contact: Name: Email contact via H. Lundbeck A/S; Phone Number: +45 36301311; Email: HQ_Medinfo@Lundbeck.com

Study Locations

• Australia
  • Melbourne, Australia, 3004
    • Recruiting
    • The Alfred Hospital
  • New South Wales
    • Randwick, New South Wales, Australia, 2031
      • Recruiting
      • Prince of Wales Hospital
    • Randwick, New South Wales, Australia, 2031
      • Recruiting
      • Sydney Children's Hospital
    • Westmead, New South Wales, Australia, 2145
      • Recruiting
      • Children's Hospital at Westmead
  • Queensland
    • Herston, Queensland, Australia, 4006
      • Recruiting
      • Royal Brisbane & Women's Hospital
    • South Brisbane, Queensland, Australia, 4101
      • Recruiting
      • Queensland CHILDREN'S HOSPITAL
  • Victoria
    • Heidelberg, Victoria, Australia, 3084
      • Recruiting
      • Austin Hospital
    • Parkville, Victoria, Australia, 3052
      • Recruiting
      • Royal Children's Hospital Melbourne
• Belgium
  • Leuven, Belgium, 3000
    • Recruiting
    • UZ Leuven - PPDS
  • Antwerp
    • Edegem, Antwerp, Belgium, 2650
      • Recruiting
      • UZ Antwerpen
• Brazil
  • São Paulo, Brazil, 05403-010
    • Recruiting
    • Instituto de Psiquiatria HC FMUSP
  • Paraná
    • Curitiba, Paraná, Brazil, 81210-310
      • Recruiting
      • Instituto de Neurologia de Curitiba (INC)
  • Rio Grande do Sul
    • Porto Alegre, Rio Grande do Sul, Brazil, 90035-001
      • Recruiting
      • Hospital Moinhos de Vento
  • São Paulo
    • Ribeirão Preto, São Paulo, Brazil, 14051-140
      • Recruiting
      • Hospital Das Clinicas da Faculdade de Medicina de Ribeirão Preto - USP - PPDS
    • São José do Rio Preto, São Paulo, Brazil, 15090-000
      • Recruiting
      • Fundacao Faculdade Regional de Medicina de Sao Jose Do Rio Preto Hospital de Base - PPDS
• Canada
  • British Columbia
    • Vancouver, British Columbia, Canada, V6H 3V4
      • Recruiting
      • Children's and Women's Health Centre of British Columbia-4480 Oak St
  • Ontario
    • London, Ontario, Canada, N6A 5W9
      • Recruiting
      • London Health Sciences Centre -800 Commissioners Rd E
• China
  • Beijing, China, 100045
    • Recruiting
    • Beijing Children's Hospital, Capital Medical University - PIN
  • Beijing Municipality
    • Beijing, Beijing Municipality, China, 102627
      • Recruiting
      • Peking University First Hospital - Daxing Campus
  • Guangdong
    • Guangzhou, Guangdong, China, 510260
      • Recruiting
      • The Second Affiliated Hospital of Guangzhou Medical University
    • Shenzhen, Guangdong, China, 518000
      • Recruiting
      • Shenzhen Children's Hospital
  • Hubei
    • Wuhan, Hubei, China, 430010
      • Recruiting
      • Wuhan Children's Hospital
  • Shanghai Municipality
    • Shanghai, Shanghai Municipality, China, 201102
      • Recruiting
      • Children's Hospital of Fudan University
• France
  • Bron, France, 69500
    • Recruiting
    • Hospices Civils de Lyon - Hôpital Pierre Wertheimer
  • Marseille, France, 13386
    • Recruiting
    • AP-HM- Hôpital de La Timone
  • Paris, France, 75015
    • Recruiting
    • Hôpital Necker - Enfants Malades
  • Paris, France, 75019
    • Recruiting
    • AP-HP - Hôpital universitaire Robert-Debré
  • Rennes, France, 35203
    • Recruiting
    • CHU de Rennes - Hopital Pontchaillou
  • Strasbourg, France, 67098
    • Recruiting
    • CHU de Strasbourg - Hôpital de Hautepierre
  • Toulouse, France, 31330
    • Recruiting
    • Centre Hospitalier Universitaire de Toulouse
  • Nord
    • Lille, Nord, France, 59000
      • Recruiting
      • Hôpital Roger Salengro
• Germany
  • Bielefeld, Germany, 33617
    • Recruiting
    • Gesellschaft für Epilepsieforschung e.V.
  • Kiel, Germany, 24105
    • Recruiting
    • Universitätsklinikum Schleswig-Holstein - Campus Kiel
  • Ravensburg, Germany, 88214
    • Recruiting
    • Epilepsie-Zentrum Bodensee
  • Hesse
    • Frankfurt am Main, Hesse, Germany, 60596
      • Recruiting
      • Klinikum der Johann-Wolfgang Goethe-Universitat
  • North Rhine-Westphalia
    • Bonn, North Rhine-Westphalia, Germany, 53127
      • Recruiting
      • Universitatsklinikum Bonn
  • Saxony
    • Radeberg, Saxony, Germany, 01454
      • Completed
      • Epilepsiezentrum Kleinwachau gemeinnützige GmbH
• Italy
  • Genova, Italy, 16147
    • Recruiting
    • Istituto G Gaslini Ospedale Pediatrico IRCCS (Duplicate)
  • Roma, Italy, 00165
    • Recruiting
    • IRCCS Ospedale Pediatrico Bambino Gesù - INCIPIT - PIN
  • Lazio
    • Rome, Lazio, Italy, 00168
      • Recruiting
      • Fondazione Policlinico Universitario A Gemelli - Rome - PPDS
  • Lombardy
    • Milan, Lombardy, Italy, 20133
      • Recruiting
      • Fondazione IRCCS Istituto Neurologico Carlo Besta
    • Pavia, Lombardy, Italy, 27100
      • Recruiting
      • Fondazione Istituto Neurologico Nazionale Casimiro Mondino IRCCS
  • Tuscany
    • Florence, Tuscany, Italy, 50139
      • Recruiting
      • Azienda Ospedaliero Universitaria A Meyer (Duplicate)
  • Veneto
    • Verona, Veneto, Italy, 37126
      • Recruiting
      • Azienda Ospedaliera Universitaria Integrata di Verona
• Japan
  • Mibu-Machi, Shimotsugagun, Japan, 321-0293
    • Recruiting
    • Dokkyo Medical University Hospital
  • Chiba
    • Narita, Chiba, Japan, 286-8520
      • Recruiting
      • IUHW Narita Hospital
  • Fukuoka
    • Fukuoka, Fukuoka, Japan, 813-0017
      • Recruiting
      • Fukuoka Children's Hospital
  • Hokkaidô
    • Sapporo, Hokkaidô, Japan, 060-8648
      • Recruiting
      • Hokkaido University Hospital
  • Niigata
    • Niigata, Niigata, Japan, 950-2074
      • Recruiting
      • National Hospital Organization Nishi-Niigata Chuo National Hospital
  • Okayama-ken
    • Okayama, Okayama-ken, Japan, 700-8558
      • Recruiting
      • Okayama University Hospital
  • Osaka
    • Osaka-Shi Miyakojima-Ku, Osaka, Japan, 534-0021
      • Recruiting
      • Osaka City General Hospital
  • Saitama
    • Saitama-shi, Saitama, Japan, 330-8777
      • Recruiting
      • Saitama Prefectural Children's Medical Center
  • Shizuoka
    • Shizuoka, Shizuoka, Japan, 420-0953
      • Recruiting
      • National Hospital Organization Shizuoka Institute of Epilepsy and Neurological Disorders
  • Tokyo
    • Kodaira-Shi, Tokyo, Japan, 187-8502
      • Recruiting
      • National Center of Neurology and Psychiatry
• Latvia
  • Rīgas Apriņķis
    • Riga, Rīgas Apriņķis, Latvia, LV-1004
      • Recruiting
      • Children's Clinical University Hospital
• Netherlands
  • Utrecht, Netherlands, 3584 CX
    • Recruiting
    • Universitair Medisch Centrum Utrecht - PPDS
• Portugal
  • Coimbra, Portugal, 3000-602
    • Recruiting
    • ULS de Coimbra, EPE - Hospital Pediátrico de Coimbra
  • Lisbon, Portugal, 1649-035
    • Recruiting
    • ULS de Santa Maria,EPE - Hospital de Santa Maria - PPDS
  • Porto, Portugal, 4050-651
    • Recruiting
    • ULS de Santo António, EPE - Centro Materno Infantil Norte
• Serbia
  • Belgrade, Serbia, 11000
    • Recruiting
    • Clinic for Neurology and Psychiatry for Children and Youth
  • Belgrade, Serbia, 190133
    • Recruiting
    • Mother and Child Health Care Institute of Serbia Dr Vukan Cupic
  • Kragujevac, Serbia, 34000
    • Recruiting
    • University Clinical Center Kragujevac
  • Belgrade
    • Belgrade, Belgrade, Serbia, 11000
      • Recruiting
      • University Clinical Center of Serbia - Dr Subotica 6 - PPDS
• Spain
  • Barcelona, Spain, 8041
    • Recruiting
    • Hospital de la Santa Creu i Sant Pau
  • Barcelona, Spain, 08035
    • Recruiting
    • Hospital Universitario Vall d'Hebron - PPDS
  • Madrid, Spain, 28009
    • Recruiting
    • Hospital Infantil Universitario Niño Jesus - PIN
  • Madrid, Spain, 28010
    • Recruiting
    • Hospital Universitario Vithas Madrid La Milagrosa
  • Madrid, Spain, 28034
    • Recruiting
    • Hospital Ruber Internacional (Grupo Quironsalud)
  • Málaga, Spain, 29016
    • Recruiting
    • Hospital Vithas Malaga
  • Valencia, Spain, 46026
    • Recruiting
    • Hospital Universitari i Politecnic La Fe de Valencia
  • Barcelona
    • Espluges de Llobregat, Barcelona, Spain, 08950
      • Recruiting
      • Hospital Sant Joan de Deu - PIN
  • Málaga
    • Málaga, Málaga, Spain, 29010
      • Recruiting
      • Hospital Regional Universitario de Malaga - Hospital General
  • Navarre
    • Pamplona, Navarre, Spain, 31008
      • Recruiting
      • Hospital Universitario de Navarra
• United Kingdom
  • Birmingham, United Kingdom, B15 2GW
    • Recruiting
    • Queen Elizabeth Hospital Birmingham
  • Glasgow, United Kingdom, G51 4TF
    • Recruiting
    • Queen Elizabeth University Hospital - PPDS
  • London, United Kingdom, NW1 2PG
    • Recruiting
    • University College London Hospitals (UCLH) - PPDS
  • London, United Kingdom, WC1N 3JH
    • Recruiting
    • Great Ormond Street Hospital - PPDS
  • Southampton, United Kingdom, SO16 6YD
    • Recruiting
    • Southampton General Hospital
  • Northamptonshire
    • Newcastle upon Tyne, Northamptonshire, United Kingdom, NE1 4LP
      • Recruiting
      • Royal Victoria Infirmary
  • South Glamorgan
    • Cardiff, South Glamorgan, United Kingdom, CF14 4XW
      • Recruiting
      • Noah's Ark Children's Hospital for Wales - PIN
• United States
  • Arkansas
    • Little Rock, Arkansas, United States, 72202
      • Recruiting
      • Arkansas Children's Hospital - PIN
  • California
    • Los Angeles, California, United States, 90095-3075
      • Recruiting
      • David Geffen School of Medicine at UCLA
    • Los Angeles, California, United States, 90027-6062
      • Recruiting
      • Children's Hospital Los Angeles - PIN
    • Palo Alto, California, United States, 94304-1510
      • Recruiting
      • The Stanford Division of Child Neurology
    • San Francisco, California, United States, 94143-2350
      • Recruiting
      • UCSF Children's Hospital
  • Colorado
    • Aurora, Colorado, United States, 80045-7106
      • Recruiting
      • Children's Hospital Colorado.
  • District of Columbia
    • Washington D.C., District of Columbia, United States, 20010-2916
      • Recruiting
      • Children's National Medical Center
  • Florida
    • Gulf Breeze, Florida, United States, 32561-4458
      • Recruiting
      • NW FL Clinical Research Group, LLC
    • Miami, Florida, United States, 33155-3009
      • Recruiting
      • Nicklaus Children's Hospital - PIN
    • Miami, Florida, United States, 33136-2107
      • Recruiting
      • University of Miami - 1120 NW 14th St
    • Orlando, Florida, United States, 32806-5411
      • Completed
      • Research Institute of Orlando LLC
    • Tampa, Florida, United States, 33609-4190
      • Recruiting
      • Pediatric Epilepsy and Neurology Specialists
    • Tampa, Florida, United States, 33606
      • Recruiting
      • University of South Florida - 2 Tampa General Circle
  • Georgia
    • Atlanta, Georgia, United States, 30329
      • Completed
      • Rare Disease Research, LLC - Atlanta - RDR - PIN
    • Atlanta, Georgia, United States, 30329
      • Recruiting
      • Children's Healthcare of Atlanta - Center for Advanced Pediatrics - PIN
  • Idaho
    • Boise, Idaho, United States, 83702-5029
      • Recruiting
      • Consultants In Epilepsy and Neurology PLLC
  • Illinois
    • Chicago, Illinois, United States, 60611
      • Recruiting
      • Ann and Robert H Lurie Childrens Hospital of Chicago - PIN
  • Iowa
    • Iowa City, Iowa, United States, 52242-1009
      • Recruiting
      • University of Iowa Hospitals & Clinics - (CRS)
  • Maryland
    • Bethesda, Maryland, United States, 20817-1844
      • Recruiting
      • Mid-Atlantic Epilepsy and Sleep Center
  • Massachusetts
    • Boston, Massachusetts, United States, 02114
      • Recruiting
      • Massachusetts General Hospital - 175 Cambridge St
  • Minnesota
    • Rochester, Minnesota, United States, 55905-0001
      • Recruiting
      • Mayo Clinic - PIN
  • New Jersey
    • Livingston, New Jersey, United States, 07039-5817
      • Recruiting
      • Institute of Neurology and Neurosurgery at Saint Barnabas, LLC
    • Morristown, New Jersey, United States, 07960
      • Recruiting
      • Northeast Regional Epilepsy Group - Morristown - 310 Madison Ave
  • New York
    • New York, New York, United States, 10016-4852
      • Recruiting
      • NYU Comprehensive Epilepsy Center - BRANY - PPDS
  • Oregon
    • Portland, Oregon, United States, 97239-3011
      • Recruiting
      • Oregon Health and Science University
  • Tennessee
    • Memphis, Tennessee, United States, 38103-2816
      • Recruiting
      • Le Bonheur Childrens Outpatient Center - PIN
  • Texas
    • Austin, Texas, United States, 78757
      • Recruiting
      • Child Neurology Consultants of Austin - 6811 Austin Center Blvd
    • Fort Worth, Texas, United States, 76104-2710
      • Recruiting
      • Cook Children's Jane and John Justin Neurosciences Center - PIN
    • Houston, Texas, United States, 77030
      • Recruiting
      • The University of Texas Medical School at Houston
  • Washington
    • Tacoma, Washington, United States, 98405-4048
      • Recruiting
      • Multicare Health System - Mary Bridge Pediatrics

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Child; Adult; Older Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• Participants who are characterized as having Lennox-Gastaut Syndrome (LGS) must fulfill all of the following criteria:

  • Onset of seizures at ≤8 years old
  • History of tonic/tonic-atonic seizures plus at least 1 of the following seizure type(s): atypical absence, atonic, myoclonic, focal impaired awareness, generalized tonic-clonic, nonconvulsive status epilepticus, or epileptic spasms
  • Presence of developmental plateauing or regression
  • History of electroencephalogram (EEG) showing generalized slow (<2.5 Hertz [Hz]) spike-and-wave complexes

• Participants who are characterized as having DEE (Other) must fulfill all of the following criteria:

  • Does not meet criteria for LGS
  • Onset of seizures at ≤5 years old
  • Presence of developmental plateauing or regression
  • History of multiple seizure types
  • History of interictal EEG background showing diffuse or multifocal slowing (with or without epileptiform activity)
• The participant has a current occurrence of at least 1 of the following countable motor seizure types: generalized tonic-clonic, tonic (bilateral), clonic (bilateral), atonic (bilateral) with truncal/leg involvement, focal motor (including hemiclonic), and focal to bilateral tonic-clonic.
• The participant has demonstrated an average of at least 4 countable motor seizures per month for each of the 3 months prior to Screening.
• The participant has been taking 1 to 4 antiseizure medications (ASMs) at a stable dose for at least 4 weeks prior to Screening.
• The participant, parent, or caregiver is willing and able (in the judgment of the investigator) to comply with completion of the diaries throughout the study.
• The participant must be willing and able to provide written informed consent; in instances where the participant is unable to provide consent, an appropriate legal representative.

Exclusion Criteria:

• The participant has a diagnosis of Dravet Syndrome (DS) or has a mutation of the Sodium channel protein type 1 subunit alpha (SCN1A) gene consistent with DS.
• The participant has been admitted to a medical facility for treatment of status epilepticus requiring mechanical ventilation within 3 months prior to Screening.
• The participant has a neurodegenerative disorder as indicated by magnetic resonance imaging or genetic testing.
• The participant has an acquired lesion/injury unrelated to the primary etiology that could contribute as a secondary cause of seizures.
• The participant is receiving exclusionary medications.
• The participant is currently using any cannabis product or cannabidiol that is not in oral solution/capsule/tablet form, not obtained from a government-approved dispensary, or contains ≥50% Delta-9-tetrahydrocannabinol (THC).
• The participant has unstable, clinically significant neurologic (other than the disease being studied; eg, recurrent strokes), psychiatric, cardiovascular (eg, pulmonary arterial hypertension, cardiac valvulopathy, orthostatic hypotension/tachycardia), pulmonary, hepatic, renal, metabolic, gastrointestinal, urologic, immunologic, hematopoietic, or endocrine disease or other abnormality which may impact the ability of the participant to participate or potentially confound the study results.
• The participant is unable or unwilling to comply with any of the study requirements or timelines.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Quadruple

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Placebo Comparator: Placebo; Placebo for LP352	Drug: Placebo; Participants will be administered with matching placebo orally or through G-tube/ PEG tube.; Other Names: Placebo Comparator
Experimental: LP352; Participants will be titrated up to highest tolerated dose of LP352 during the Titration period (Visit 2 - Visit 5), followed by maintenance period (Visit 5 - Visit 8) and then taper/down titration period.	Drug: LP352; LP352 will be administered orally or through G-tube/ percutaneous endoscopic gastrostomy (PEG) tube; Other Names: Bexicaserin

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Frequency Percent Change in Countable Motor Seizures During Treatment Compared to Baseline	The percent change from Baseline in countable motor seizure frequency during Treatment will be calculated as countable motor seizure frequency during Treatment minus countable motor seizure frequency during Screening and divided by seizure frequency during Screening and multiplied by 100 where each seizure frequency will be based on number of seizures.	Baseline and up to 15 Weeks

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Frequency Percent Change in Countable Motor Seizures during Maintenance compared to Baseline		Baseline and up to 15 Weeks
Safety and Tolerability of LP352	Safety and tolerability as measured by incidence and severity of Treatment Emergent Adverse Events (TEAEs), Serious Adverse events (SAEs), AEs leading to discontinuation and clinically significant changes in laboratory parameters (hematology, serum chemistry and Urinalysis), physical examination findings, vital signs, growth parameters (height and weight), 12-lead electrocardiograms (ECGs), Columbia-Suicide Severity Rating Scale (C-SSRS) responses, and Patient Health Questionnaire-9 (PHQ-9) total score and Question 9 score.	Up to 21 Weeks
Percentage of participants with ≥ 50% Reduction in countable motor seizures during the Treatment compared to Baseline		Baseline and up to 15 Weeks

Collaborators and Investigators

• Sponsor: Longboard Pharmaceuticals

Study record dates

Study Major Dates

• Study Start (Actual): November 11, 2024
• Primary Completion (Estimated): October 31, 2026
• Study Completion (Estimated): November 30, 2026

Study Registration Dates

• First Submitted: December 2, 2024
• First Submitted That Met QC Criteria: December 2, 2024
• First Posted (Actual): December 5, 2024

Study Record Updates

• Last Update Posted (Actual): May 18, 2026
• Last Update Submitted That Met QC Criteria: May 14, 2026
• Last Verified: May 1, 2026

More Information

Terms related to this study

• Keywords: Epilepsy; Seizures; Lennox-Gastaut Syndrome (LGS); Neurodevelopmental disorders; Developmental and epileptic encephalopathy; LP352; Bexicaserin; Antiseizure medications (ASMs); DEEp OCEAN
• Additional Relevant MeSH Terms: Epileptic Syndromes; Neurologic Manifestations; Brain Diseases; Central Nervous System Diseases; Nervous System Diseases; Mental Disorders; Genetic Diseases, Inborn; Congenital, Hereditary, and Neonatal Diseases and Abnormalities; Pathological Conditions, Signs and Symptoms; Signs and Symptoms; Neurodevelopmental Disorders; Epilepsy; Seizures; Lennox Gastaut Syndrome; Substandard Drugs; Pharmaceutical Preparations; Counterfeit Drugs
• Other Study ID Numbers: LP352-301; 2024-516412-17-00 (Ctis)

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: UNDECIDED

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: Yes
• Studies a U.S. FDA-regulated device product: No
• product manufactured in and exported from the U.S.: No