Generalized Anxiety DisorderPhase 2/3NCT05729373
A Clinical Study That Will Measure How Well SEP-363856 Works and How Safe it is in Adults With Generalized Anxiety Disorder
A Phase 2/3 study testing SEP-363856 in people with Generalized Anxiety Disorder, run by Otsuka Pharmaceutical Development & Commercialization, Inc. at 83 sites in 8 countries.
Trial summary
A clinical study that will meaure how well SEP-363856 works and how safe it is in adults with Generalized Anixety Disorder. This study will be accepting both male and female subjects between the ages of 18 years and 65 years old. Read more about this study
- Who is it for?
- Ages 18 to 65 years
- Conditions the study is for
- Generalized Anxiety Disorder
- What is being tested?
- SEP-363856
- Type of treatment
- Pill or oral medicine
- Could I receive a placebo?
- Yes, some participants may receive a placebo
- How many people
- 434 participants
- Where
- 83 sitesin 8 countries
- Study dates
- 8 Mar 2023to 26 Sep 2025
- Phase
- Phase 2/3
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 to 65 years
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- Male or female subject between 18 to 65 years of age.
- Subject meets DSM-5 criteria for a diagnosis of Generalized Anxiety Disorder.
- Subject must be willing and able to comply with the study procedures and visit schedule and must be able to understand and follow verbal and written instructions.
Who cannot join
- Subject has DSM-5-based diagnosis of any disorder other than Generalized Anxiety Disorder that was the primary focus of treatment within 12 months before Screening.
- Subjects who report an inadequate response to more than 3 antidepressant treatments
- Subject is at significant risk of harming self or others based on Investigator's judgment.
- Subject has any clinically significant unstable medical condition or any clinically significant chronic disease that in the opinion of the Investigator, would limit the subject's ability to complete and/or participate in the study.
- Female subject who is pregnant, lactating, or plans to get pregnant during the study.
Trial locations and contacts
83 sites in 8 countries.
83 sites in 8 countries
United States38 sites
Lehigh Center for Clinical Research, LLC
Allentown, Pennsylvania, 18104
CenExel iResearch Atlanta
Atlanta, Georgia, 30030
Advanced Discovery Research LLC
Atlanta, Georgia, 30318
NeuroTrials Research, Inc.
Atlanta, Georgia, 30328
Psychiatry and Psychotherapy Partners Austin
Austin, Texas, 78737
Copley Clinical
Boston, Massachusetts, 02116
Boston Clinical Trials
Boston, Massachusetts, 02131
Social Psychiatry Research Institute
Brooklyn, New York, 11235
Neurobehavioral Research, Inc.
Cedarhurst, New York, 11516
Center for Emotional Fitness Site
Cherry Hill, New Jersey, 08002
Uptown Research Institute, LLC
Chicago, Illinois, 60640
ProScience Research Group
Culver City, California, 90230
FutureSearch Trials of Dallas, LP
Dallas, Texas, 75231
Cedar Clinical Research, Inc.
Draper, Utah, 84020
University of Alabama at Birmingham
Huntsville, Alabama, 35801
CNS Healthcare
Jacksonville, Florida, 32256
CenExel Hassman Research Institute
Marlton, New Jersey, 08053
Bioscience Research, LLC
Mount Kisco, New York, 10016
Berman Clinical
New York, New York, 10029
Manhattan Behavioral Medicine
New York, New York, 10036
The Medical Research Network, L.L.C
New York, New York, 10128
Neuro-Behavioral Clinical Research, Inc.
North Canton, Ohio, 44720
Excell Research, Inc.
Oceanside, California, 92056
Sooner Clinical Research
Oklahoma City, Oklahoma, 73112
Paradigm Research Professionals, LLP
Oklahoma City, Oklahoma, 73116
Combined Research Orlando
Orlando, Florida, 32803
IMA Clinical Research Phoenix
Phoenix, Arizona, 85012
Anderson Clinical Research
Redlands, California, 92374
Midwest Research Group
Saint Charles, Missouri, 63304
CenExel iResearch Savannah
Savannah, Georgia, 31405
California Neuroscience Research, LLC
Sherman, California, 91403
Schuster Medical Research Institute
Sherman Oaks, California, 91403
K2 Medical Research, LLC
Tampa, Florida, 33607
Viking Pharmaceutical Trials Inc. dba Viking Clinical Research
Temecula, California, 92591
CenExel Collaborative Neuroscience Research
Torrance, California, 90502
Pacific Clinical Research Management Group
Upland, California, 91786
American Medical Research, Inc.
Warrenville, Illinois, 60555
Adams Clinical
Watertown, Massachusetts, 02472
Japan14 sites
Uematsu Mental Clinic
Chikugo-shi, Fukuoka, 833-0041
Hiro Mental Clinic
Fukuoka, Fukuoka, 810-0004
Shinseikai Kaku Mental Clinic
Fukuoka, Fukuoka, 810-0022
Mental Clinic Sakurazaka
Fukuoka, Fukuoka, 810-0023
Kokura Mental Clinic
Kitakyushu-shi, Fukuoka, 802-0006
Hayakawa Clinic
Kure-shi, Hiroshima, 737-0111
Hirota Clinic
Kurume-shi, Fukuoka, 830-0033
Senzoku Psychosomatic Medicine Clinic
Meguro-ku, Tokyo-To, 152-0012
Akari Clinic
Naha, Okinawa, 900-0004
Higashi-Sapporo Mental Clinic
Sapporo, Hokkaido, 003-0003
Shimode Mental Clinic
Sapporo, Hokkaido, 062-0922
Sangenjaya Nakamura Mental Clinic
Setagaya-ku, Tokyo-To, 154-0004
Sangenjaya Neurology- Psychosomatic Clinic
Setagaya-ku, Tokyo-To, 154-0004
Barclay Imuro Mental Clinic
Urasoe-shi, Okinawa, 901-2104
Bulgaria9 sites
Medical Center Medconsult Pleven OOD
Pleven, 5800
Medical Center Mentalcare OOD
Sofia, Plovdiv, 4004
MHC - Sofia, EOOD
Sofia, 1000
Medical Center "Sv.Naum"
Sofia, 1113
DCC "Sv. Vrach and Sv. Sv. Kuzma and Damyan", OOD
Sofia, 1408
Medical Center Hera EOOD
Sofia, 1510
Medical Center Intermedica, OOD
Sofia, 1680
DCC "Mladost M" - Varna, OOD Site #156
Varna, 9020
DCC "Mladost M" - Varna, OOD Site #157
Varna, 9020
Spain6 sites
Hospital Universitario Fundacion Alcorcon
Alcorcón, Madrid, 28922
Hospital de la Santa Creu i Sant Pau
Barcelona, 8025
Institucion Hospitalaria Hestia Palau
Barcelona, 8025
Hospital Valle del Nalon
Langreo, Principality of Asturias, 33920
Hospital Universitario Infanta Leonor
Madrid, 28031
Hospital de Antequera
Málaga, 29200
Finland5 sites
Aava Laakarikeskus - Aava Kamppi
Helsinki, 00100
Mederon Oy
Helsinki, 00100
Savon Psykiatripalvelu Oy
Kuopio, Northern Savonia, 70110
Oulu Mentalcare Oy
Oulu, 90100
Satakunnan Psykiatripalvelu
Tampere, 33210
Slovakia5 sites
MENTUM, s.r.o.
Bratislava, 82007
Epamed sro
Košice, 040 01
PsychoLine s.r.o.
Rimavská Sobota, 97901
Crystal Comfort s.r.o.
Vranov nad Topľou, 9301
BONA MEDIC, s.r.o.
Zlaté Moravce, 95301
Sweden4 sites
Sahlgrenska Universitetssjukhuset - Östra sjukhuset
Gothenburg, 416 50
ProbarE- Lund
Lund, 22222
PharmaSite AB Malmö
Malmö, 21152
ProbarE- Stockholm
Stockholm, 113 29
Estonia2 sites
Marienthali Kliinik
Tallinn, 11315
Tartu University Hospital
Tartu, 50417
About this study
Official title: A Phase 2/3, Randomized, Double-blind, Parallel Group, Placebo-controlled, Flexible-dose, Multicenter Study to Evaluate the Efficacy and Safety of SEP-363856 in the Treatment of Adults With Generalized Anxiety Disorder
A clinical study that will meaure how well SEP-363856 works and how safe it is in adults with Generalized Anixety Disorder. This study will be accepting both male and female subjects between the ages of 18 years and 65 years old. The study will be held in Approximately 50 global study centers and approximately 15 additional centers for a separate Japan population. Participation in the study can be up to approximately 12 weeks.
Read the detailed description
This is a multicenter, randomized, double-blind, parallel-group, flexible dose, outpatient study evaluating the efficacy and safety of SEP-363856 flexibly dosed (50 - 75 mg/day) versus placebo over an 8-week Treatment Period in subjects with GAD. This study is projected to randomize approximately 434 subjects to 2 treatment groups (SEP-363856 [50 - 75 mg/day] or placebo) in a 1:1 ratio.
Approximately 30 additional subjects (N = 15 per treatment group) are projected to enroll in the Japan Cohort. Treatment assignment will be stratified by country. Study drug will be taken at approximately the same time each evening at bedtime .
- Conditions
- Generalized Anxiety Disorder
- Being tested
- SEP-363856, Placebo
- Keywords
- Generalized Anxiety Disorder
- Medical subject headings
- Generalized Anxiety Disorder
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
SEP-363856Drug
once daily tablet
PlaceboDrug
once daily tablet
| Study group | Role | What they receive |
|---|---|---|
| SEP-363856 | Experimental | dosed once daily tablet Receives: Drug: SEP-363856 |
| Placebo | Placebo comparator | dosed once daily tablet Receives: Drug: Placebo |
What is being measured
The primary outcome is the main question the study is designed to answer.
Change from Baseline in Hamilton Anxiety Rating Scale (HAM-A) total score at Endpoint
The HAM-A scale consists of 14 items, each defined by a series of symptoms. Each item is rated on a 5-point (0-4) scale, with higher scores indicating greater severity.
Measured: Week 8
Secondary outcomes (1)
Change from Baseline in Clinical Global Impression-Severity (CGI-S) score at Endpoint
The CGI-S is a clinician-rated assessment of the subject's current illness state on a 7-point scale, where a higher score is associated with greater illness severity.
Measured: Week 8
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted15 Feb 2023
- Study start8 Mar 2023
- Primary completion26 Sep 2025
- Study completion26 Sep 2025
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Generalized Anxiety DisorderStudies of the same condition, open and under way.
- More trials run by Otsuka Pharmaceutical Development & Commercialization, Inc.The sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase 2/3
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Model description
- Randomized, Double-blind, Parallel group, Placebo-controlled
- Masking
- Quadruple blind
- Who is masked
- Participant, Care provider, Investigator, Outcomes assessor
- Enrolment
- 434 participants (actual)
Sponsor and investigators
- Sponsor type
- Industry (pharma, biotech, devices)
- Responsible party
- Sponsor
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT05729373
- Sponsor's protocol ID
- SEP361-226
- Other IDs
- 2022-502077-42-00, jRCT2031230152
- Status last verified
- Oct 2025
- First submitted
- 6 Feb 2023
- Last updated
- 10 Oct 2025
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- Yes
- FDA-regulated device
- No
- Individual data sharing
- Yes: Anonymized Individual participant data (IPD) that underlie the results of this study will be shared with researchers to achieve aims pre-specified in a methodologically sound research proposal. Small studies with less than 25 participants are excluded from data sharing.
Study at a glance
From the registry record, last updated by the sponsor on 10 Oct 2025. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- A Phase 2/3, Randomized, Double-blind, Parallel Group, Placebo-controlled, Flexible-dose, Multicenter Study to Evaluate the Efficacy and Safety of SEP-363856 in the Treatment of Adults With Generalized Anxiety Disorder
- ClinicalTrials.gov ID
- NCT05729373
- Acronym / sponsor ID
- SEP361-226
- Conditions
- Generalized Anxiety Disorder
- Keywords
- Generalized Anxiety Disorder
- Phase
- Phase 2/3
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 434 participants (actual)
- Lead sponsor
- Otsuka Pharmaceutical Development & Commercialization, Inc.Industry (pharma, biotech, devices)
- Study start
- 8 Mar 2023 (actual)
- Primary completion
- 26 Sep 2025 (actual)
- Study completion
- 26 Sep 2025 (actual)
- First posted
- 15 Feb 2023 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
A clinical study that will meaure how well SEP-363856 works and how safe it is in adults with Generalized Anixety Disorder. This study will be accepting both male and female subjects between the ages of 18 years and 65 years old. The study will be held in Approximately 50 global study centers and approximately 15 additional centers for a separate Japan population. Participation in the study can be up to approximately 12 weeks.
Detailed description
This is a multicenter, randomized, double-blind, parallel-group, flexible dose, outpatient study evaluating the efficacy and safety of SEP-363856 flexibly dosed (50 - 75 mg/day) versus placebo over an 8-week Treatment Period in subjects with GAD. This study is projected to randomize approximately 434 subjects to 2 treatment groups (SEP-363856 [50 - 75 mg/day] or placebo) in a 1:1 ratio.
Approximately 30 additional subjects (N = 15 per treatment group) are projected to enroll in the Japan Cohort. Treatment assignment will be stratified by country. Study drug will be taken at approximately the same time each evening at bedtime .
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Quadruple blind (participant, care provider, investigator, outcomes assessor)
- Number of arms
- 2
- Model description
- Randomized, Double-blind, Parallel group, Placebo-controlled
| Arm | Type | Receives |
|---|---|---|
| SEP-363856 | Experimental | Drug: SEP-363856dosed once daily tablet |
| Placebo | Placebo comparator | Drug: Placebodosed once daily tablet |
Who may qualify
- Ages
- 18 to 65 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (3 listed)
- Male or female subject between 18 to 65 years of age.
- Subject meets DSM-5 criteria for a diagnosis of Generalized Anxiety Disorder.
- Subject must be willing and able to comply with the study procedures and visit schedule and must be able to understand and follow verbal and written instructions.
Key exclusion criteria (5 listed)
- Subject has DSM-5-based diagnosis of any disorder other than Generalized Anxiety Disorder that was the primary focus of treatment within 12 months before Screening.
- Subjects who report an inadequate response to more than 3 antidepressant treatments
- Subject is at significant risk of harming self or others based on Investigator's judgment.
- Subject has any clinically significant unstable medical condition or any clinically significant chronic disease that in the opinion of the Investigator, would limit the subject's ability to complete and/or participate in the study.
- Female subject who is pregnant, lactating, or plans to get pregnant during the study.
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| SEP-363856once daily tablet | Drug | SEP-363856 |
| Placeboonce daily tablet | Drug | Placebo |
Primary outcome
Change from Baseline in Hamilton Anxiety Rating Scale (HAM-A) total score at Endpoint
Time frame: Week 8
The HAM-A scale consists of 14 items, each defined by a series of symptoms. Each item is rated on a 5-point (0-4) scale, with higher scores indicating greater severity.
1 secondary outcome
Change from Baseline in Clinical Global Impression-Severity (CGI-S) score at Endpoint
Time frame: Week 8
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 10 Oct 2025.
- Individual participant dataSharing planned: Yes. Anonymized Individual participant data (IPD) that underlie the results of this study will be shared with researchers to achieve aims pre-specified in a methodologically sound research proposal. Small studies with less than 25 participants are excluded from data sharing.
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
The record lists no contact. Use the official record to reach the sponsor.
83 sites in 8 countries: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Phase 2/3 study testing SEP-363856 in people with Generalized Anxiety Disorder, run by Otsuka Pharmaceutical Development & Commercialization, Inc. at 83 sites in 8 countries.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 3 inclusion and 5 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 10 Oct 2025. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 83 sites in United States, Japan, Bulgaria, Spain, Finland and 3 more countries. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. Some participants in this study may receive a placebo. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
What does this combined phase mean?
Phase 2 studies give the treatment to a larger group to see whether it has the intended effect and to keep checking safety.
Phase 3 studies compare the treatment with the current standard treatment or a placebo in a large group, to confirm how well it works and watch for side effects.
Not every study follows the same path, and some studies (observational studies, device studies) have no phase.
Are results available for this study?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Change from Baseline in Hamilton Anxiety Rating Scale (HAM-A) total score at Endpoint (time frame: Week 8). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 10 Oct 2025.