NCT04652882 · Vanda Pharmaceuticals
Evaluating the Effects of Tasimelteon Vs. Placebo in Delayed Sleep-Wake Phase Disorder (DSWPD)
What this study is about
This is a conducted at multiple hospitals, where neither patients nor doctors know which treatment is given, randomly assigned study to evaluate the effectiveness and safety of a daily single taken by mouth dose of tasimelteon and matching placebo in male and female participants with DSWPD.
View original scientific description
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.
Interventions
DRUG
Tasimelteon
oral capsule
DRUG
Placebo
oral capsule
Primary outcome measures
Change in Sleep Onset over the treatment period, as measured by sleep diary.
Time frame: 28 days
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
- 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.
Where
- Los Angeles, California
- Redwood City, California
- Aurora, Colorado
- Boston, Massachusetts
- St Louis, Missouri
- New Hyde Park, New York
- Cincinnati, Ohio
- Cleveland, Ohio
- Columbia, South Carolina
- San Antonio, Texas
- Sherman, Texas
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 Dec 2, 2025 · Source of record for eligibility and locations