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

Phase 3

Recruiting

• Conditions: Developmental and Epileptic Encephalopathy
• Interventions: Drug: Placebo; Drug: LP352

• Registration Number: NCT06719141
• Lead Sponsor: Longboard Pharmaceuticals

Brief Summary

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.

Detailed Description

Not available

Study Timeline

• Study Start: 2024-11-11
• Study First Submitted: 2024-12-02
• Study First Submitted QC: 2024-12-02
• Study First Posted: 2024-12-05
• Status Verified: 2025-05
• Last Update Submitted: 2025-05-08
• Last Update Posted: 2025-05-13
• Primary Completion: 2026-10
• Study Completion: 2026-11

Recruitment & Eligibility

• Status: RECRUITING
• Sex: All
• Target Recruitment: 320

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 has used of 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 & Design

• Study Type: INTERVENTIONAL
• Study Design: PARALLEL

Arm && Interventions

Group	Intervention	Description
Placebo	Placebo	Placebo for LP352
LP352	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.

Primary Outcome Measures

Name	Time	Method
Frequency Percent Change in Countable Motor Seizures During Treatment Compared to Baseline	Baseline and up to 15 Weeks	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.

Secondary Outcome Measures

Name	Time	Method
Safety and Tolerability of LP352	Up to 21 Weeks	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.
Percentage of participants with ≥ 50% Reduction in countable motor seizures during the Treatment compared to Baseline	Baseline and up to 15 Weeks
Frequency Percent Change in Countable Motor Seizures during Maintenance compared to Baseline	Baseline and up to 15 Weeks

Trial Locations

Locations (99)

Site Number - CHN 01; 🇨🇳 Beijing, China

Site Number - FRA 08; 🇫🇷 Bron, France

Site Number - FRA 04; 🇫🇷 Lille, France

Site Number - USA19; 🇺🇸 Little Rock, Arkansas, United States

Site Number - USA29; 🇺🇸 La Jolla, California, United States

Site Number - USA26; 🇺🇸 Los Angeles, California, United States

Site Number - USA18; 🇺🇸 Los Angeles, California, United States

Site Number - USA24; 🇺🇸 Palo Alto, California, United States

Site Number - USA28; 🇺🇸 San Francisco, California, United States

Site Number - USA17; 🇺🇸 Aurora, Colorado, United States

Site Number - USA02; 🇺🇸 Gulf Breeze, Florida, United States

Site Number - USA37; 🇺🇸 Miami, Florida, United States

Site Number - USA05; 🇺🇸 Orlando, Florida, United States

Site Number - USA 08; 🇺🇸 Tampa, Florida, United States

Site Number - USA11; 🇺🇸 Tampa, Florida, United States

Site Number - USA09; 🇺🇸 Atlanta, Georgia, United States

Site Number - USA38; 🇺🇸 Chicago, Illinois, United States

Site Number - USA 13; 🇺🇸 Iowa City, Iowa, United States

Site Number - USA07; 🇺🇸 Bethesda, Maryland, United States

Site Number - USA30; 🇺🇸 Boston, Massachusetts, United States

Site Number - USA40; 🇺🇸 Boston, Massachusetts, United States

Site Number - USA15; 🇺🇸 Rochester, Minnesota, United States

Site Number - USA10; 🇺🇸 Livingston, New Jersey, United States

Site Number - USA36; 🇺🇸 Morristown, New Jersey, United States

Site Number - USA32; 🇺🇸 New York, New York, United States

Site Number - USA14; 🇺🇸 Cincinnati, Ohio, United States

Site Number - USA39; 🇺🇸 Cleveland, Ohio, United States

Site Number - USA35; 🇺🇸 Columbus, Ohio, United States

Site Number - USA33; 🇺🇸 Portland, Oregon, United States

Site Number - USA22; 🇺🇸 Charleston, South Carolina, United States

Site Number - USA34; 🇺🇸 Memphis, Tennessee, United States

Site Number - USA41; 🇺🇸 Austin, Texas, United States

Site Number - USA31; 🇺🇸 Fort Worth, Texas, United States

Site Number - USA25; 🇺🇸 Houston, Texas, United States

Site Number - USA03; 🇺🇸 Tacoma, Washington, United States

Site Number - AUS07; 🇦🇺 Randwick, New South Wales, Australia

Site Number - AUS08; 🇦🇺 Randwick, New South Wales, Australia

Site Number - AUS 09; 🇦🇺 Westmead, New South Wales, Australia

Site Number - AUS04; 🇦🇺 Herston, Queensland, Australia

Site Number - AUS05; 🇦🇺 South Brisbane, Queensland, Australia

Site Number - AUS02; 🇦🇺 Heidelberg, Victoria, Australia

Site Number - AUS03; 🇦🇺 Melbourne, Victoria, Australia

Site Number - AUS 06; 🇦🇺 Parkville, Victoria, Australia

Site Number - BEL 01; 🇧🇪 Edegem, Belgium

Site Number - BEL 02; 🇧🇪 Leuven, Belgium

Site Number - BRA 01; 🇧🇷 Curitiba, PR, Brazil

Site Number - BRA 02; 🇧🇷 Ribeirão Preto, SP, Brazil

Site Number - BRA 05; 🇧🇷 São José Do Rio Preto, SP, Brazil

Site Number - BRA 03; 🇧🇷 São Paulo, SP, Brazil

Site Number - CAN 04; 🇨🇦 Vancouver, British Columbia, Canada

Site Number - CAN 01; 🇨🇦 Toronto, Ontario, Canada

Site Number - CAN 03; 🇨🇦 Toronto, Ontario, Canada

Site Number - FRA 06; 🇫🇷 Marseille, France

Site Number - FRA 09; 🇫🇷 Paris, France

Site Number - FRA 05; 🇫🇷 Paris, France

Site Number - FRA 01; 🇫🇷 Rennes, France

Site Number - FRA 07; 🇫🇷 Strasbourg, France

Site Number - FRA 03; 🇫🇷 Toulouse, France

Site Number - DEU 02; 🇩🇪 Bielefeld, Germany

Site Number - DEU 07; 🇩🇪 Bonn, Germany

Site Number - DEU 01; 🇩🇪 Frankfurt, Germany

Site Number - DEU 04; 🇩🇪 Freiburg im Breisgau, Germany

Site Number - DEU 03; 🇩🇪 Kiel, Germany

Site Number - DEU 06; 🇩🇪 Radeberg, Germany

Site Number - DEU 05; 🇩🇪 Ravensburg, Germany

Site Number - ITA 03; 🇮🇹 Genova, Italy

Site Number - ITA 07; 🇮🇹 Milan, Italy

Site Number - ITA 02; 🇮🇹 Pavia, Italy

Site Number - ITA 06; 🇮🇹 Roma, Italy

Site Number - ITA 01; 🇮🇹 Roma, Italy

Site Number - ITA 04; 🇮🇹 Toscana, Italy

Site Number - ITA 08; 🇮🇹 Verona, Italy

Site Number - LVA 01; 🇱🇻 Riga, Latvia

Site Number - MEX 01; 🇲🇽 Mexico City, Cdmx, Mexico

Site Number - MEX 02; 🇲🇽 Mexico City, Mexico

Site Number - NLD 02; 🇳🇱 Zwolle, BV, Netherlands

Site Number - NLD 03; 🇳🇱 Utrecht, CX, Netherlands

Site Number - PRT 02; 🇵🇹 Coimbra, Portugal

Site Number - PRT 03; 🇵🇹 Lisbon, Portugal

Site Number - PRT 05; 🇵🇹 Porto Covo, Portugal

Site number - SRB 06; 🇷🇸 Belgrade, Serbia

Site Number - SRB 02; 🇷🇸 Belgrade, Serbia

Site Number - SRB 03; 🇷🇸 Kragujevac, Serbia

Site number - ESP 05; 🇪🇸 Barcelona, Spain

Site number - ESP 12; 🇪🇸 Barcelona, Spain

Site number - ESP 02; 🇪🇸 Barcelona, Spain

Site number - ESP 10; 🇪🇸 Madrid, Spain

Site number - ESP 11; 🇪🇸 Madrid, Spain

Site number - ESP 03; 🇪🇸 Madrid, Spain

Site number - ESP 04; 🇪🇸 Málaga, Spain

Site number - ESP 09; 🇪🇸 Málaga, Spain

Site number - ESP 06; 🇪🇸 Pamplona, Spain

Site number - ESP 08; 🇪🇸 Valencia, Spain

Site number - GBR 01; 🇬🇧 Birmingham, United Kingdom

Site number - GBR 04; 🇬🇧 Glasgow, United Kingdom

Site number - GBRXX; 🇬🇧 London, United Kingdom

Site number - GBR 03; 🇬🇧 London, United Kingdom

Site number - GBR 05; 🇬🇧 Newcastle Upon Tyne, United Kingdom

Site number - GBR 02; 🇬🇧 Southampton, United Kingdom