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

Phase 3

Recruiting

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

• Registration Number: NCT06908226
• Lead Sponsor: Longboard Pharmaceuticals

Brief Summary

This (DEEp OLE Study) is a multicentre, open-label study to investigate the long-term safety, efficacy, tolerability, and pharmacokinetics (PK) of LP352 in the treatment of seizures in children and adults with DEE who completed Study LP352-301 or LP352-302. The study consists of 3 main phases: Screening, Titration period and Maintenance period, followed by a Taper period and Follow-Up. The total duration of the study will be approximately 14 months.

Detailed Description

Not available

Study Timeline

• Study Start: 2025-02-12
• Study First Submitted: 2025-03-06
• Study First Submitted QC: 2025-03-26
• Study First Posted: 2025-04-03
• Status Verified: 2025-05
• Last Update Submitted: 2025-05-08
• Last Update Posted: 2025-05-13
• Primary Completion: 2027-11
• Study Completion: 2027-12

Recruitment & Eligibility

• Status: RECRUITING
• Sex: All
• Target Recruitment: 324

Inclusion Criteria

• The participant has satisfactorily completed Study LP352-301 or LP352-302 Visit 8, and who, in the opinion of the investigator, may benefit from continued LP352 administration.
• Diagnosis of DEE that includes Dravet Syndrome (DS), Lennox-Gastaut Syndrome (LGS), or DEE Other (as defined and evaluated in Study LP352-301 or LP352-302).
• Has at least one reliable and consistent parent, legal guardian, or caregiver during the study.
• The participant or legal representative must be willing and able to provide written informed consent
• 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.

Exclusion Criteria

• The participant is receiving exclusionary medications.
• Current use of any cannabis product or cannabidiol that is not in oral solution/capsule/tablet form, not obtained from a government-approved dispensary, or containing ≥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: SINGLE_GROUP

Arm && Interventions

Group	Intervention	Description
LP352	LP352	Participants will be titrated up to highest tolerated dose of LP352 during the Titration period (Visit 1 - Visit 3), followed by maintenance period (Visit 4 - Visit 14) and then taper/down titration period (Visit 15 - Visit 17).

Primary Outcome Measures

Name	Time	Method
Number of participants reporting Treatment emergent adverse events (TEAEs) and serious adverse events (SAEs) and AEs leading to discontinuation	Up to 61 Weeks	An AE is defined as any untoward medical occurrence in a participant enrolled into this study, regardless of its causal relationship to the study drug. A treatment-emergent AE is defined as any event that is not present before exposure to study drug or any event or condition that is already present that worsens in either intensity or frequency after exposure to study drug. An SAE is defined as any event that: Results in death; Is life-threatening; requires inpatient hospitalization or prolongation of existing hospitalization. "Inpatient hospitalization" includes admission to an emergency room for observation and/or treatment that would have been insufficient in an outpatient setting; results in persistent or significant disability/incapacity; Is a congenital anomaly/birth defect or is an important medical event. An adverse event of special interest (AESI) is an AE or SAE is defined as an AE or SAE of scientific or medical concern specific to the sponsor's product or program.
Number of Participants With Clinically Significant Changes in Chemistry parameters	Up to 61 Weeks
Number of Participants With Clinically Significant Changes in Hematology parameters	Up to 61 Weeks
Number of Participants With Clinically Significant Changes in Urinalysis	Up to 61 Weeks
Number of participants with clinically significant changes in vital signs	Up to 61 Weeks
Number of participants with clinically significant changes in physical examinations	Up to 61 Weeks
Number of participants with clinically significant changes in growth parameters	Up to 61 Weeks
Number of participants with clinically significant changes in electrocardiogram (ECG) parameters	Up to 61 Weeks
Number of participants with postive responses to Columbia-Suicide Severity Rating Scale (C-SSRS)	Up to 61 Weeks	C-SSRS was developed by researchers at Columbia University as a tool to help systematically assess suicidal ideation and behavior. It is composed of questions addressing suicidal ideation and suicidal behavior, as well as self-injurious behavior without suicidal intent. The tool will be administered by a trained operator/interviewer (investigator or designee) via interview with the participant at the study time points. If the participant is unable to complete the C-SSRS due to developmental status, the participant's legally acceptable representative may not complete the C SSRS. In these cases, the investigator may use clinical judgment to assess both the participant's status regarding suicidality and ability to complete the scale, both of which must then be documented in the source document.
Number of participants with positive responses to Patient Health Questionnaire-9 (PHQ-9) and Question 9	Up to 61 Weeks	The PHQ-9 is a multipurpose instrument for Screening, diagnosing, monitoring, and measuring the severity of depression. The scale is an easy-to-use participant questionnaire that is a self-administered version of the Primary Care Evaluation of Mental Disorders diagnostic instrument for common mental disorders. The PHQ-9 is the depression module, which scores each of the 9 Diagnostic and Statistical Manual of Mental Disorders IV, Text Revision criteria as "0" (not at all) to "3" (nearly every day). It has been validated for use in primary care. Participants with a depression score of greater than 9 (mild) on the PHQ-9 scale or a positive response to Question 9 should be excluded from the study. When there is a positive response to PHQ-9 Question 9 post randomization, the investigator should determine whether an AE has occurred.

Secondary Outcome Measures

Name	Time	Method
Frequency Percent Change in Countable Motor Seizures During Treatment Compared to Baseline	Baseline and up to 55 weeks	The percent change from Baseline in countable motor seizure frequency during Treatment will be calculated as (countable motor seizure frequency during Treatment) - (countable motor seizure frequency during Baseline \[Visit 1 of LP352-301 and LP352-302\]) ÷ seizure frequency during Baseline \[Visit 1 of LP352-301 and LP352-302\]) × 100
Percentage of participants with ≥ 50% Reduction in countable motor seizures during Treatment compared to Baseline [Visit 1 of LP352-301 and LP352-302]	Baseline and up to 55 weeks
Frequency Percent Change in Countable Motor Seizures during Maintenance compared to Baseline [Visit 1 of LP352-301 and LP352-302]	Baseline and up to 55 weeks

Trial Locations

Locations (33)

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 - USA11; 🇺🇸 Tampa, Florida, United States

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

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

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

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

Site Number - USA10; 🇺🇸 Livingston, New Jersey, 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 - USA31; 🇺🇸 Fort Worth, Texas, United States

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

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

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

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

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

Site Number - AUS08; 🇦🇺 Randwick, 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