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Taking people in United StatesPhase 3

A Trial of the Efficacy and Safety of Fixed Doses of SEP-363856 in Adults With Generalized Anxiety Disorder

Key facts

Who runs it
Otsuka Pharmaceutical Development & Commercialization, Inc.
Where
Boston, Dallas, DeSoto, Encino, Gainesville, Independence, Jacksonville, Las Vegas, Maitland, New Orleans, New York, Oklahoma City, Sherman Oaks, Tucson, Warrenville, and Washington D.C., United StatesSee the 17 sites
Status
Recruiting
Phase
Phase 3
People taking part
576 people, planned
Started
28 Jul 2026
Expected to end
13 Dec 2028
Type of study
Interventional, 3 groupsOne group gets a placebo (a dummy treatment), for comparison.
Treatments tested
  • SEP-363856
  • Placebo
Record updated
26 October 2026

Who can take part

Age
18 years and older
Sex
Women and men
Healthy volunteers
Cannot take part

The registry criteria, word for word

Show all 17 criteriaShow less

Who can take part

  • Male or female participants at least 18 years of age at the time of informed consent
  • Primary diagnosis of Generalized Anxiety Disorder (GAD) per Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5), confirmed by Mini-International Neuropsychiatric Interview (MINI) and clinical psychiatric evaluation
  • Body Mass Index (BMI) between 18 and 40 kilograms per square meter (kg/m\^2) (inclusive)
  • Participant is willing and able to comply with study procedures and visit schedule
  • Medically stable as determined by medical history, physical exam, vital signs, and laboratory tests
  • Willing and able to discontinue prohibited medications/therapies per protocol
  • i) Females of childbearing potential: negative pregnancy test and agreement to use acceptable contraception ii) Males: agreement to follow protocol-defined contraception and reproductive restrictions
  • Participant is willing and able to safely discontinue all prohibited medications/therapies/herbal supplements in accordance with the protocol-required washouts prior to baseline/Day 1 and during the trial period

Who cannot take part

  • Current DSM-5 diagnosis of major depressive episode, post traumatic stress disorder (PTSD), or any psychiatric disorder other than GAD that was the primary focus of treatment within 12 months prior to screening
  • Substance use disorder (excluding nicotine/caffeine) within 12 months prior to screening
  • Use of prohibited medications/therapies within protocol-defined timeframes (e.g., certain antipsychotics, mood stabilizers, benzodiazepines, investigational treatments)
  • Prior exposure to restricted treatments
  • Lifetime history of certain psychiatric disorders (e.g., schizophrenia spectrum disorders, bipolar disorder, obsessive-compulsive disorder, borderline or antisocial personality disorder)
  • Known history of human immunodeficiency virus seropositivity, hepatitis B or C
  • Significant suicide risk (e.g., recent suicidal behavior/ideation per Columbia-Suicide Severity Rating Scale [C-SSRS] or MADRS)
  • Pregnant or breastfeeding females
  • Participation in another investigational study within 180 days (or more than [>] 1 trial in last year)

Where in United States

  • Adams Clinical BostonBoston, United StatesContact: Dougherty (principal investigator)Taking people
  • FutureSearch Trials of DallasDallas, United StatesContact: Downing (principal investigator)Taking people
  • Adams Clinical DallasDeSoto, United StatesContact: Kurian (principal investigator)Taking people
  • Pharmacology Research InstituteEncino, United StatesContact: Grosz (principal investigator)Taking people
  • Sarkis Clinical Trials - GainesvilleGainesville, United StatesContact: Sarkis (principal investigator)Taking people
  • Insight Clinical TrialsIndependence, United StatesContact: Stillman (principal investigator)Taking people
  • Clinical Neuroscience Solutions, LLCJacksonville, United StatesContact: Joyce (principal investigator)Taking people
  • Vector Clinical Trials - Las VegasLas Vegas, United StatesContact: Childress (principal investigator)Taking people
  • Accel Research Sites - MaitlandMaitland, United StatesContact: Marraffino (principal investigator)Taking people
  • Research Works, IncNew Orleans, United StatesContact: Doucette (principal investigator)Taking people
  • Adams Clinical HarlemNew York, United StatesContact: Noone (principal investigator)Taking people
  • Manhattan Behavioral Medicine PLLCNew York, United StatesContact: Joseph (principal investigator)Taking people
  • Sooner Clinical Research, Inc.Oklahoma City, United StatesContact: Sebastian (principal investigator)Taking people
  • California Neuroscience Research Medical Group, Inc.Sherman Oaks, United StatesContact: Shiovitz (principal investigator)Taking people
  • Del Sol Research ManagementTucson, United StatesContact: Bupp (principal investigator)Taking people
  • AMR Conventions Research, IncWarrenville, United StatesContact: Gaonkar (principal investigator)Taking people
  • Emerson Clinical Research Institute - Washington, DCWashington D.C., United StatesContact: Lawson (principal investigator)Taking people

About the trial

What the trial wants to find out

This is a global, phase 3, randomized, double-blind, parallel-group, 3-arm, placebo-controlled, multicenter study designed to compare the efficacy, safety, and tolerability of fixed doses of SEP-363856 (50 and 75 milligrams per day [mg/day]) to placebo in adults at least 18 years of age with generalized anxiety disorder (GAD) over 8 weeks.

The 3 groups in the trial

  • SEP-363856 50 mgTreatment being tested

    Participants will receive 50 milligrams (mg) SEP-363856 tablet, orally, once a day (QD) from Days 1 to 56.

    Treatment: SEP-363856

  • SEP-363856 75 mgTreatment being tested

    Participants will receive 50 mg SEP-363856 tablet, orally, QD, from Days 1 to 3 and then 75 mg tablet from Days 4 to 56.

    Treatment: SEP-363856

  • PlaceboPlacebo, for comparison

    Participants will receive SEP-363856-matching placebo tablet, orally, QD from Days 1 to 56.

Questions to ask the study team

  1. How often do I need to come in, and for how long each time?
  2. Are travel costs paid?
  3. Can I keep my own doctor?
  4. What happens if I want to stop?

Contact the study team: see the registry record → Contacts and Locations

Print a page for my doctor

Data and sources

Registry record
Listed on ClinicalTrials.gov and on the EU's official list of trials (CTIS).
Official title
A Phase 3, Randomized, Double-Blind, Parallel-Group, Placebo-Controlled, Multicenter Trial to Compare the Efficacy and Safety of Fixed Doses of SEP-363856 to Placebo in the Treatment of Adults With Generalized Anxiety Disorder
Record updated
26 October 2026
A Trial of the Efficacy and Safety of Fixed Doses of SEP-363856 in Adults With Generalized Anxiety Disorder (NCT07759128) – Frontlight Research