NCT06660394 · Longboard Pharmaceuticals
A Phase 3, Placebo-Controlled Study to Investigate LP352 in Children and Adults With Dravet Syndrome (DS)
What this study is about
This (DEEp SEA 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 DS.
View original scientific description
This (DEEp SEA 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 DS. The study consists of 3 main phases: Screening, Titration period, and Maintenance period, followed by a Taper period and Follow-Up. Participants will be randomized to LP352 or placebo. 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
- Diagnosis of DS must fulfill all of the following criteria: 1. Participants with seizure onset age \>1 and \<20 months 2. The participant has a history of at least 1 of the following seizure type(s): prolonged generalized tonic-clonic, hemiclonic, myoclonic, tonic, atonic, atypical absence, focal impaired awareness, nonconvulsive status epilepticus
- The participant has a current occurrence of at least 1 of the following countable motor seizure types: generalized tonic-clonic, tonic (bilateral), clonic (bilateral), atonic (bilateral) with truncal/leg involvement, focal motor (including hemiclonic), and focal to bilateral tonic-clonic
- The participant has demonstrated an average of at least 4 countable motor seizures per month for the 3 months prior to Screening.
- The participant has been taking 1 to 4 antiseizure medications (ASMs) at a stable dose for at least 4 weeks prior to Screening.
- The participant, parent, or caregiver is willing and able (in the
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
- Chicago, Illinois
And 11 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