Open-label, Long-term Safety Study of LP352 in Subjects With Developmental and Epileptic Encephalopathy
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ClinicalTrials.gov Identifier: NCT05626634 |
Recruitment Status :
Recruiting
First Posted : November 25, 2022
Last Update Posted : January 13, 2023
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Condition or disease | Intervention/treatment | Phase |
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Developmental and Epileptic Encephalopathy Dravet Syndrome Lennox-Gastaut Syndrome | Drug: LP352 | Phase 2 |
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.
Study Type : | Interventional (Clinical Trial) |
Estimated Enrollment : | 50 participants |
Allocation: | N/A |
Intervention Model: | Single Group Assignment |
Masking: | None (Open Label) |
Primary Purpose: | Treatment |
Official 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 |
Actual Study Start Date : | November 8, 2022 |
Estimated Primary Completion Date : | October 2024 |
Estimated Study Completion Date : | October 2024 |

Arm | Intervention/treatment |
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Experimental: LP352
Subjects will be titrated up to highest tolerated dose of LP352 during a 15-day period, followed by a 48-week maintenance period and a 15-day taper/down titration period.
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Drug: LP352
LP352 6 mg, 9 mg or 12 mg administered three times daily, orally or through G-tube |
- 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
- 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
- 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
- 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
- Proportion of Subjects with > 50% Reduction in Total Seizures During the Treatment Period [ Time Frame: Baseline to Week 50 ]
- Percent Reduction in Individual Seizure Type During the Treatment Period [ Time Frame: Baseline to Week 50 ]
- Proportion of Subjects Requiring Rescue Medication During the Treatment Period [ Time Frame: Baseline to Week 50 ]
- Percent Change from Baseline in the Number of Episodes of Status Epilepticus During the Treatment Period [ Time Frame: Baseline to Week 50 ]
- Percent of Subjects with Countable Motor Seizure-free Days During the Treatment Period [ Time Frame: Baseline to Week 50 ]
- Percentage Change from Baseline in Non-motor and Difficult to Count Seizures [ Time Frame: Baseline to Week 50 ]
- LGS: Percentage Change from Baseline in the Frequency of Observed Drop Seizures Over the Treatment Period [ Time Frame: Baseline to Week 50 ]

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Ages Eligible for Study: | 12 Years to 65 Years (Child, Adult, Older Adult) |
Sexes Eligible for Study: | All |
Accepts Healthy Volunteers: | No |
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

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.
Please refer to this study by its ClinicalTrials.gov identifier (NCT number): NCT05626634
Contact: Longboard Study Contact | 858-999-8858 | clinicalstudies@longboardpharma.com |

Principal Investigator: | Dennis J Dlugos, MD | Children's Hospital of Philadelphia |
Responsible Party: | Longboard Pharmaceuticals |
ClinicalTrials.gov Identifier: | NCT05626634 |
Other Study ID Numbers: |
LP352-202 |
First Posted: | November 25, 2022 Key Record Dates |
Last Update Posted: | January 13, 2023 |
Last Verified: | December 2022 |
Studies a U.S. FDA-regulated Drug Product: | Yes |
Studies a U.S. FDA-regulated Device Product: | No |
CDKL5 deficiency disorder developmental and epileptic encephalopathy Dravet Syndrome epilepsy |
Lennox-Gastaut Syndrome treatment resistant epilepsy tuberous sclerosis complex |
Brain Diseases Epilepsy Epilepsies, Myoclonic Lennox Gastaut Syndrome Syndrome Disease |
Pathologic Processes Central Nervous System Diseases Nervous System Diseases Epilepsy, Generalized Epileptic Syndromes Genetic Diseases, Inborn |