for people ages 12-65 (full criteria)
at San Francisco, California and other locations
study started
completion around



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.

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


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.


Developmental and Epileptic Encephalopathy, Dravet Syndrome, Lennox-Gastaut Syndrome, CDKL5 deficiency disorder, epilepsy, treatment resistant epilepsy, tuberous sclerosis complex, Brain Diseases, Myoclonic Epilepsies, Lennox Gastaut Syndrome, Syndrome, LP352, bexicaserin


You can join if…

Open to people ages 12-65

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

You CAN'T join if...

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


  • UCSF
    San Francisco California 94158 United States
  • Rancho Los Amigos National Rehabilitation Center (RLANRC)
    Downey California 90242 United States


in progress, not accepting new patients
Start Date
Completion Date
Longboard Pharmaceuticals
Phase 2 research study
Study Type
Expecting 50 study participants
Last Updated