Evaluating the Effects of Tasimelteon vs. Placebo in Delayed Sleep-Wake Phase Disorder (DSWPD)
July 24, 2026 updated by: Vanda Pharmaceuticals
A Multicenter, Double-blind, Randomized Study to Evaluate the Effects of Tasimelteon vs. Placebo in Participants With Delayed Sleep-Wake Phase Disorder (DSWPD)
This is a multicenter, double-blind, randomized study to evaluate the efficacy and safety of a daily single oral dose of tasimelteon and matching placebo in male and female participants with DSWPD.
Study Overview
Status
Active, not recruiting
Intervention / Treatment
Study Type
Interventional
Enrollment (Estimated)
70
Phase
- Phase 3
Contacts and Locations
This section provides the contact details for those conducting the study, and information on where this study is being conducted.
Study Locations
-
-
-
Innsbruck, Austria, 6020
- Vanda Investigational Site
-
Vienna, Austria, 1090
- Vanda Investigational Site
-
-
-
-
-
Berlin, Germany, 10117
- Vanda Investigational Site
-
Hamburg, Germany, 20253
- Vanda Investigational Site
-
Marburg, Germany, 35043
- Vanda Investigational Site
-
Schwerin, Germany, 19053
- Vanda Investigational Site
-
-
-
-
California
-
Los Angeles, California, United States, 90025
- Vanda Investigational Site
-
Redwood City, California, United States, 94063
- Vanda Investigational Site
-
-
Colorado
-
Aurora, Colorado, United States, 80045
- Vanda Investigational Site
-
-
Massachusetts
-
Boston, Massachusetts, United States, 02115
- Vanda Investigational Site
-
-
Missouri
-
St Louis, Missouri, United States, 63123
- Vanda Investigational Site
-
-
New York
-
New Hyde Park, New York, United States, 11042
- Vanda Investigational Site
-
-
Ohio
-
Cincinnati, Ohio, United States, 45212
- Vanda Investigational Site
-
Cleveland, Ohio, United States, 44195
- Vanda Investigational Site
-
-
South Carolina
-
Columbia, South Carolina, United States, 29201
- Vanda Investigational Site
-
-
Texas
-
San Antonio, Texas, United States, 78229
- Vanda Investigational Site
-
Sherman, Texas, United States, 75092
- Vanda Investigational Site
-
-
Participation Criteria
Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.
Eligibility Criteria
Ages Eligible for Study
18 years to 75 years (Adult, Older Adult)
Accepts Healthy Volunteers
No
Description
Inclusion Criteria:
- Ability and acceptance to provide written informed consent.
- A confirmed clinical diagnosis of Delayed Sleep-Wake Phase Disorder (DSWPD).
- Men or women between 18 - 75 years, inclusive.
- Body Mass Index (BMI) of ≥ 18 and ≤ 35 kg/m^2.
Exclusion Criteria:
- Exacerbation of an existing psychiatric condition that requires change in treatment or intervention in the past 3 months.
- Major surgery, trauma, illness, general anesthesia, or immobility for 3 or more days within the last 30 days.
- Pregnancy, recent pregnancy (within 6 weeks), or women who are breastfeeding.
- A positive test for substances of abuse.
- Current tobacco user.
Study Plan
This section provides details of the study plan, including how the study is designed and what the study is measuring.
How is the study designed?
Design Details
- Primary Purpose: Treatment
- Allocation: Randomized
- Interventional Model: Parallel Assignment
- Masking: Quadruple
Arms and Interventions
Participant Group / Arm |
Intervention / Treatment |
|---|---|
|
Placebo Comparator: Placebo
|
oral capsule
|
|
Experimental: Tasimelteon
|
oral capsule
|
What is the study measuring?
Primary Outcome Measures
Outcome Measure |
Time Frame |
|---|---|
|
Change in Sleep Onset over the treatment period, as measured by sleep diary.
Time Frame: 28 days
|
28 days
|
Secondary Outcome Measures
Outcome Measure |
Time Frame |
|---|---|
|
Change in nighttime objective sleep-wake parameters such as sleep time, as measured by actigraphy.
Time Frame: 28 days
|
28 days
|
|
Change in nighttime subjective sleep-wake parameters such as sleep time, as measured by sleep diary.
Time Frame: 28 days
|
28 days
|
|
Assessment of safety and tolerability of daily single dose of tasimelteon, as measured by spontaneous reporting of adverse events (AEs).
Time Frame: 28 days
|
28 days
|
Collaborators and Investigators
This is where you will find people and organizations involved with this study.
Sponsor
Publications and helpful links
The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.
Study record dates
These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.
Study Major Dates
Study Start (Actual)
December 9, 2020
Primary Completion (Estimated)
September 1, 2026
Study Completion (Estimated)
September 1, 2026
Study Registration Dates
First Submitted
November 19, 2020
First Submitted That Met QC Criteria
December 2, 2020
First Posted (Actual)
December 3, 2020
Study Record Updates
Last Update Posted (Actual)
July 27, 2026
Last Update Submitted That Met QC Criteria
July 24, 2026
Last Verified
July 1, 2026
More Information
Terms related to this study
Additional Relevant MeSH Terms
Other Study ID Numbers
- VP-VEC-162-3502
Plan for Individual participant data (IPD)
Plan to Share Individual Participant Data (IPD)?
NO
Drug and device information, study documents
Studies a U.S. FDA-regulated drug product
Yes
Studies a U.S. FDA-regulated device product
No
product manufactured in and exported from the U.S.
No
This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.