NCT06719141 · Longboard Pharmaceuticals
A Study to Investigate LP352 in Children and Adults With Developmental and Epileptic Encephalopathies (DEE)
What this study is about
This (DEEp OCEAN Study) is a where neither patients nor doctors know which treatment is given, randomly assigned, compared against an inactive treatment, conducted at multiple hospitals study to investigate the effectiveness, safety, and tolerability of LP352 in the treatment of seizures in children and adults with DEE.
View original scientific description
This (DEEp OCEAN Study) is a double-blind, randomized, placebo-controlled, multicenter study to investigate the efficacy, safety, and tolerability of LP352 in the treatment of seizures in children and adults with DEE. The study consists of 3 main phases: Screening, Titration period, Maintenance period, followed by a Taper period and Follow-Up. The total duration of the study will be approximately 24 months.
Interventions
DRUG
LP352
LP352 will be administered orally or through G-tube/ percutaneous endoscopic gastrostomy (PEG) tube
DRUG
Placebo
Participants will be administered with matching placebo orally or through G-tube/ PEG tube.
Primary outcome measures
Frequency Percent Change in Countable Motor Seizures During Treatment Compared to Baseline
Time frame: Baseline and up to 15 Weeks
The percent change from Baseline in countable motor seizure frequency during Treatment will be calculated as countable motor seizure frequency during Treatment minus countable motor seizure frequency during Screening and divided by seizure frequency during Screening and multiplied by 100 where each seizure frequency will be based on number of seizures.
Who can participate
This study lists these criteria on ClinicalTrials.gov. A study coordinator reviews eligibility during screening — this page does not determine whether you qualify.
Inclusion criteria
- Participants who are characterized as having Lennox-Gastaut Syndrome (LGS) must fulfill all of the following criteria:
- Onset of seizures at ≤8 years old
- History of tonic/tonic-atonic seizures plus at least 1 of the following seizure type(s): atypical absence, atonic, myoclonic, focal impaired awareness, generalized tonic-clonic, nonconvulsive status epilepticus, or epileptic spasms
- Presence of developmental plateauing or regression
- History of electroencephalogram (EEG) showing generalized slow (\<2.5 Hertz \[Hz\]) spike-and-wave complexes
- Participants who are characterized as having DEE (Other) must fulfill all of the following criteria:
- Does not meet criteria for LGS
- Onset of seizures at ≤5 years old
- Presence of developmental plateauing or regression
- History of multiple seizure types
- History of interictal EEG background showing diffuse or multifocal slowing (with or without epileptiform activity)
- The participant has a cu
Where
- Little Rock, Arkansas
- Los Angeles, California
- Palo Alto, California
- San Francisco, California
- Aurora, Colorado
- Washington D.C., District of Columbia
- Gulf Breeze, Florida
- Miami, Florida
- Orlando, Florida
- Tampa, Florida
- Atlanta, Georgia
- Boise, Idaho
And 14 more locations — see the full list below.
Related conditions & keywords
Frequently asked questions
What is a clinical trial?
A clinical trial is a research study that tests new medical treatments, drugs, devices, or procedures to determine their safety and effectiveness. Trials are carefully designed and monitored to protect participants while advancing medical knowledge.
Is it safe to participate?
Clinical trials follow strict safety guidelines and ethical standards. Trials must be reviewed and approved, and participants are closely monitored by medical professionals throughout the study. You can withdraw at any time if you choose.
Will I be compensated?
Many clinical trials offer compensation for your time, travel expenses, and inconvenience. The specific compensation varies by study and will be discussed during the screening process. All study-related medical care is typically provided at no cost to participants.
Will I receive a placebo instead of treatment?
When effective treatment exists, participants typically receive either the standard treatment plus the study intervention, or the standard treatment plus placebo. You would not be denied effective care. Placebos are primarily used when no proven treatment is available, or in addition to standard care. Your trial consent form will clearly explain what treatments you may receive.
Can I leave a trial if I change my mind?
Absolutely. Participation in clinical trials is completely voluntary. You have the right to withdraw from the study at any time, for any reason, without penalty or loss of benefits to which you are otherwise entitled.
How long does a clinical trial last?
Trial duration varies widely depending on the study design and purpose. Some trials last just a few weeks, while others may continue for months or years. The study coordinator will provide specific timeline information during your screening call.
Data: ClinicalTrials.gov · synced Jun 12, 2026 · Source of record for eligibility and locations