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Completed

NCT Number: NCT05626634

Open-label, Long-term Safety Study of LP352 in Subjects With Developmental and Epileptic Encephalopathy

The objective of this study is to assess the long-term safety, tolerability, and efficacy of adjunctive therapy of LP352 in subjects with developmental and epileptic encephalopathies who completed participation in Study LP352-201.

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Key information

Conditions

Developmental and Epileptic Encephalopathy Brain Diseases CDKL5 deficiency disorder Central Nervous System Diseases Congenital Abnormalities Congenital, Hereditary, and Neonatal Diseases and Abnormalities Dravet Syndrome Epilepsies, Myoclonic Epilepsy Epilepsy, Generalized Epileptic Syndromes Genetic Diseases, Inborn Hamartoma Heredodegenerative Disorders, Nervous System Lennox Gastaut Syndrome Lennox-Gastaut Syndrome Malformations of Cortical Development Malformations of Cortical Development, Group I Neoplasms Neoplasms, Multiple Primary Neoplastic Syndromes, Hereditary Nervous System Diseases Nervous System Malformations Neurocutaneous Syndromes Neurodegenerative Diseases Tuberous Sclerosis

Age range

12 year–65 year

Sex eligibility

All sexes

Study type

Interventional

Phase

Phase 2

Primary location

Queensland Children's Hospital, South Brisbane, Queensland, Australia

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About this study

This Phase 2, multicenter, open-label, multiple-dose extension clinical study is designed to evaluate long-term safety of LP352 in subjects with developmental and epileptic encephalopathy who completed Study LP352-201.

The study consists of a Screening Period (Day -1) and a 50-week open-label Treatment Period that includes a 15-day Up-titration Period (during which time subjects will titrate up to their highest tolerated doses) and an open-label Maintenance Period (48 weeks). The Treatment Period will be followed by a Down-titration/Taper Period (up to 15 days) and Follow-up Period (14 days after completion of down-titration). The starting dose of up-titration will be 6 mg TID. The target final maintenance doses are 6 mg TID, 9 mg TID, and 12 mg TID after a 15-day up-titration period, if tolerated.

Who can participate

Healthy volunteers accepted: No

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • Male or non-pregnant, non-lactating female, age 12 to 65 years who have satisfactorily completed study LP352-201
  • Diagnosis of Dravet syndrome, Lennox-Gastaut syndrome, or other developmental and epileptic encephalopathy
  • The patient/parent/caregiver is able and willing to attend study visits, complete the diary and take study drug as instructed

Exclusion criteria

  • Had an SAE in Study LP352-201 that was definitely, probably, or possibly related to exposure to study drug
  • Current or past history of cardiovascular or cerebrovascular disease, such as cardiac valvulopathy, myocardial infarction, stroke, pulmonary arterial hypertension or abnormal blood pressure
  • Has glaucoma, renal impairment, liver disease or any other medical condition that would affect study participation or pose a risk to the subject
  • Current or recent history of moderate or severe depression, anorexia nervosa, bulimia or at risk of suicidal behavior
  • Currently taking anorectic agents, monoamine oxidase inhibitors; serotonin agonists or antagonists including fenfluramine, atomoxetine, vortioxetine, or other medications for weight loss
  • Positive test result on the drug screen, except tetrahydrocannabinol (THC) for patients taking prescribed cannabidiol

Treatment and study plan

LP352, bexicaserin

Drug

LP352 6 mg, 9 mg or 12 mg administered three times daily, orally or through G-tube

Primary outcomes

  1. Treatment-emergent Adverse Events

    Time frame: Baseline up to Week 52

    Incidence and severity of treatment-emergent adverse events, including serious adverse events and adverse events leading to study discontinuation and clinically significant changes in vital signs, physical examination endpoints, clinical safety laboratory values and ECGs

  2. Columbia-Suicide Severity Rating Scale (C-SSRS) Response

    Time frame: Baseline up to Week 52

    Type of Suicidal Ideation, Intensity (1 - 5, with 5 being most severe), Suicidal Behavior

  3. Patient Health Questionnaire-9 Total Score and Question 9 Score

    Time frame: Baseline up to Week 52

    Severity Rating Scale: 0 - 27; higher scores indicate greater severity of depressive disorder

Secondary outcomes

  1. Percent Change from Baseline in Observed Countable Motor Seizure Frequency During the Treatment Period

    Time frame: Baseline to Week 50

    Baseline Used for Seizure Frequency = Baseline from Study LP352-201 and Baseline from Study LP352-202

  2. Proportion of Subjects with > 50% Reduction in Total Seizures During the Treatment Period

    Time frame: Baseline to Week 50

  3. Percent Reduction in Individual Seizure Type During the Treatment Period

    Time frame: Baseline to Week 50

  4. Proportion of Subjects Requiring Rescue Medication During the Treatment Period

    Time frame: Baseline to Week 50

  5. Percent Change from Baseline in the Number of Episodes of Status Epilepticus During the Treatment Period

    Time frame: Baseline to Week 50

  6. Percent of Subjects with Countable Motor Seizure-free Days During the Treatment Period

    Time frame: Baseline to Week 50

  7. Percentage Change from Baseline in Non-motor and Difficult to Count Seizures

    Time frame: Baseline to Week 50

  8. LGS: Percentage Change from Baseline in the Frequency of Observed Drop Seizures Over the Treatment Period

    Time frame: Baseline to Week 50

Sponsors and collaborators

Lead sponsor

Longboard Pharmaceuticals

Industry

Registry information

Official study title

A Phase 2, Multicenter, Open-label, Long-term Safety Study of LP352 in Subjects With Developmental and Epileptic Encephalopathy Who Completed Study LP352-201 and Are Candidates for Continuous Treatment for Up to 52 Weeks

Important dates

Study start
2022
Primary completion
2024
Study completion
2024
First posted
Nov 25, 2022
Registry last updated
Dec 3, 2025

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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