ClinicalTrials.gov record NCT06908226
A Study to Investigate LP352 in Children and Adults With Developmental and Epileptic Encephalopathy (DEE)
A Phase 3, Open-Label Study to Investigate the Long-Term Safety and Efficacy of LP352 in the Treatment of Seizures in Children and Adults With Developmental and Epileptic Encephalopathy
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AI-written from the registry record, not the study's own wording. May contain errors or omissions. Check the registry text on this page and the original record ↗ before acting on it.
This Phase 3, open-label study follows people with developmental and epileptic encephalopathy (DEE) who completed earlier LP352 studies. It investigates long-term safety, tolerability, seizure effects, and how the drug behaves in the body. Study periods include screening, dose titration, maintenance, taper, and follow-up, lasting about 14 months total.
What it is studying. The study is testing long-term safety, tolerability, seizure outcomes, and pharmacokinetics of LP352 (bexicaserin) given orally or via G-tube/PEG in participants who completed prior LP352 trials.
What the researchers hope to learn. Scientific goals: to collect long-term data on safety and tolerability (adverse events, labs, ECG, growth, vital signs), to assess effects on seizure frequency and responder rates, and to measure pharmacokinetics of LP352 over up to about 61 weeks.
What this study is about
The study's own summary, as published on ClinicalTrials.gov. Underlined terms have a short explanation.
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.
Interventions being studied
Being studied in this trial does not mean the treatment or procedure is approved or available for this condition.
- Drug
- LP352
Eligibility
The criteria exactly as listed on ClinicalTrials.gov. Only the study team can say whether they apply to you.
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).
- Participant has a body weight of ≥10 kg.
- G-tubes/PEG tubes (if applicable) should be in stable and good working condition. Nasogastric tubes are not allowed except for short-term management.
- Has at least one reliable and consistent parent, legal guardian, or caregiver during 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 LAR must provide informed consent and the participant will need to assent (as per local regulations) before participation in the study. If the participant cannot provide consent or assent (ie, due to developmental status), the investigator should document why it was not obtained.
- The participant and/or authorized representative is willing to provide written consent or assent to allow the investigator and the investigator's staff to consult with the participant's medical caregivers and the medical monitor during Screening and during participation in the study.
- All participants of childbearing potential must have a negative urine or serum pregnancy (human chorionic gonadotropin) test at Visit 8 from Study LP352-301 or LP352-302 and agrees to routinely use an acceptable effective method of contraception from the time of signing informed consent up to 48 hours after the last dose of study drug.
- Participant and/or participant's caregiver(s) agree to not post any participant's personal medical data related to the study or information related to the study on any website or social media site until the study has been completed.
- 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.
- Considered at risk of suicidal behavior based on the C-SSRS at Visit 8 of LP352-301 or LP352-302. If the participant is unable to complete the C-SSRS due to developmental status, the participant's LAR 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 the ability to complete the scale, both of which must then be documented in the source document.
- Has a PHQ-9 score of >9 or a positive response to Question 9 at Visit 8 of LP352-301 or LP352-302. If the participant is unable to complete the PHQ-9, the participant's LAR may not complete the PHQ-9. In these cases, the investigator may use clinical judgment to assess both the participant's status and ability to complete the scale, both of which must then be documented in the source document.
- Ongoing AE from LP352-301 or LP352-302 of severe depression, anorexia nervosa, or bulimia per the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition.
- Has an abnormal and clinically significant 12-lead ECG at Visit 8 in LP352-301 or LP352-302 in the opinion of the investigator, for example, second- or third-degree heart block or a QTc of >450 msec for adult males, >470 msec for adult females, or >440 msec for pediatric participants.
- Ongoing AE in LP352-301 or LP352-302 of alcohol, opioid, or other drug use disorder, as per the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition.
- 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% THC. Cannabis product or cannabidiol should be used primarily to treat seizures and dose should not be adjusted for the duration of the study. Cannabis product or cannabidiol will count as a concurrent ASM.
- Has a positive result on the urine drug screen at Visit 8 of LP352-301 or LP352-302, except for positive results related to prescribed controlled medications (eg, benzodiazepine) or Epidiolex®/government-approved cannabis product/cannabidiol used to treat seizures (eg, tetrahydrocannabinol).
- 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 (severe hepatic impairment), renal (severe renal impairment), metabolic, gastrointestinal, urologic, immunologic, hematopoietic, or endocrine disease or other abnormality at Visit 8 of LP352-301 or LP352-302 which may impact the ability of the participant to participate or potentially confound the study results.
- Is pregnant, breast-feeding, or intending to become pregnant during or within 48 hours after the last dose of study drug; or intending to donate ova during such time period.
- Has a known hypersensitivity to any component of LP352 formulation or any history of serious drug-induced hypersensitivity, eg, toxic epidermal necrolysis or Drug Reaction with Eosinophilia and Systemic Symptoms.
- Unwilling to abstain from donation of blood during and within 2 weeks after the study.
- Is unable or unwilling to comply with any of the study requirements or timelines.
Study description and what participation involves
The registry record has no detailed description beyond the summary above.
AI summaryWhat participation may involve, in plain languageShow ▾Hide ▴
AI-written from the registry record, not the study's own wording. May contain errors or omissions. Check the registry text on this page and the original record ↗ before acting on it.
Participants will receive LP352 orally or via G‑tube and go through a screening, a short titration period to reach the highest tolerated dose, a maintenance period, then a taper and follow‑up — total study time is about 14 months. Regular clinic visits will include safety monitoring (blood tests, ECGs, vital signs, growth checks) and caregivers will be asked to complete seizure diaries. Mood and suicidality assessments (C‑SSRS and PHQ‑9) and urine drug screening may be performed at scheduled visits. Participants must agree not to donate blood during the study and for two weeks after the last dose.
How the study is structured. Phase 3, open-label, single-group interventional study. Participants who completed Study LP352-301 or LP352-302 enter screening, then are titrated to the highest tolerated LP352 dose, followed by a maintenance period, then taper and follow-up. No placebo or blinding is used; active treatment is continued and monitored over roughly 14 months.
Questions you could ask
These questions are suggestions for a conversation with the study team or your own clinician, not advice.
- The registry says participants are enrolled by invitation. Who decides who is invited, and how?
- The listed sites are in Australia, Belgium, Brazil, China, France, Germany, Italy, Japan, Latvia, Mexico, Portugal, Serbia, Spain, United Kingdom, United States. Is any of them reachable for me, and does the study help with travel?
- Which of the eligibility criteria would need to be checked with tests before I could join?
More on CDKL5 deficiency disorder
This trial is also listed on this site under Dravet syndrome.
Important dates
- Study start
- Feb 12, 2025
- Primary completion
- Nov 11, 2027 (estimated)
- Study completion
- Dec 17, 2027 (estimated)
- Target enrollment
- 324 participants (estimated)
- Last updated on registry
- Sep 15, 2026
- Data verified
- Oct 10, 2026
Sponsor and research team
The lead sponsor funds and oversees the trial. A pharmaceutical or biotech company sponsor typically means the study is testing that company's drug or device; a hospital, university, or government agency usually indicates investigator-initiated or publicly funded research.
- Lead sponsor
- Longboard Pharmaceuticals
Participating sites (83)
- Arkansas Children's Hospital - Cardiology Clinic
Little Rock, Arkansas, 72202-3500 · United States
- University of California Los Angeles (UCLA) - David Geffen School of Medicine - Global Health Pro...
Los Angeles, California, 90095 · United States
- Stanford University - Stanford School of Medicine - Pulmonary and Cystic Fibrosis Center
Palo Alto, California, 94304-1511 · United States
- UCSF Benioff Children's Hospitals - San Francisco
San Francisco, California, 94158 · United States
- Children's Hospital Colorado - Heart Institute
Aurora, Colorado, 80045-7106 · United States
- NW FL Clinical Research Group, LLC
Gulf Breeze, Florida, 32561-4495 · United States
- University of Miami Medical Group (UMMG)
Miami, Florida, 33136-2117 · United States
- Research Institute of Orlando LLC
Orlando, Florida, 32806 · United States
- Pediatric Epilepsy & Neurology Specialists (PENS)
Tampa, Florida, 33609-4191 · United States
- University of South Florida (USF) - Tampa Campus
Tampa, Florida, 33620 · United States
Terms used on this page · explanations by MedicalUpdates.ai
- open-label
- No masking is used, so the assigned intervention is not deliberately hidden from participants or study staff.
- pharmacokinetics
- How the body absorbs, distributes, breaks down and removes a drug. It is studied by measuring drug levels or related substances at set times after a dose.
- Follow-Up
- The period after treatment or enrolment during which participants are observed or contacted, for example to record side effects or outcomes.
- legal guardian
- A person who is legally allowed to make decisions, including consent to research, on behalf of someone who cannot consent for themselves.
- written informed consent
- The process of explaining a study, including its risks and what participation involves, so that a person can decide freely whether to take part. Consent is usually documented in writing, and a participant can choose to leave the study later.
- assent
- A child's or dependent adult's agreement to take part, given alongside the formal consent of a parent or legal representative.
- during Screening
- The checks done before enrolment to see whether a person qualifies, such as tests, scans or a review of medical history.
- childbearing potential
- Studies often ask participants who could become pregnant, or could father a child, to use contraception during the study and for a period afterwards, because the effect of the treatment on a pregnancy is unknown.
- study drug
- A treatment that is being tested and has not been approved for this use. It may be approved for a different condition. Being studied does not mean it works or is available outside the study.
- 12-lead ECG
- A recording of the heart's electrical activity. QTc is one measurement from it; some drugs are avoided if it is prolonged.
- Inclusion Criteria
- The conditions a person must meet to be considered for the study, for example a confirmed diagnosis, an age range or a test result.
- Exclusion Criteria
- The conditions that rule a person out even if they meet the inclusion criteria, for example other illnesses, certain medicines or pregnancy.
The study record on this page is reproduced from ClinicalTrials.gov, a database of the U.S. National Library of Medicine, where it was submitted by the study sponsor. MedicalUpdates.ai does not own this content, is not affiliated with or endorsed by ClinicalTrials.gov, NIH, or the U.S. Government, and does not verify the record. Plain-language notes, the glossary and the questions above are added by this site; text in the boxes marked "AI summary" was written by an AI model and may contain errors. Registry records change over time. Check the original record for the current version and discuss eligibility or participation with a qualified healthcare professional.
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