Sleep Wake DisordersPhase 3NCT04652882
Evaluating the Effects of Tasimelteon vs. Placebo in Delayed Sleep-Wake Phase Disorder (DSWPD)
A Phase 3 study testing Tasimelteon in people with Sleep Wake Disorders and Sleep Disorders, Circadian Rhythm, run by Vanda Pharmaceuticals at 17 sites in 3 countries.
Trial summary
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. Read more about this study
- Who is it for?
- Ages 18 to 75 years
- Conditions the study is for
- Sleep Wake Disorders, Sleep Disorders, Circadian Rhythm, Chronobiology Disorders
- What is being tested?
- Tasimelteon
- Type of treatment
- Pill or oral medicine
- Could I receive a placebo?
- Yes, some participants may receive a placebo
- How many people
- 43 participants
- Where
- 17 sitesin 3 countries
- Study dates
- 9 Dec 2020to 4 Sep 2026
- Phase
- Phase 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 75 years
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- 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.
Who cannot join
- 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.
Trial locations and contacts
17 sites in 3 countries.
17 sites in 3 countries
United States11 sites
Vanda Investigational Site
Aurora, Colorado, 80045
Vanda Investigational Site
Boston, Massachusetts, 02115
Vanda Investigational Site
Cincinnati, Ohio, 45212
Vanda Investigational Site
Cleveland, Ohio, 44195
Vanda Investigational Site
Columbia, South Carolina, 29201
Vanda Investigational Site
Los Angeles, California, 90025
Vanda Investigational Site
New Hyde Park, New York, 11042
Vanda Investigational Site
Redwood City, California, 94063
Vanda Investigational Site
San Antonio, Texas, 78229
Vanda Investigational Site
Sherman, Texas, 75092
Vanda Investigational Site
St Louis, Missouri, 63123
Germany4 sites
Vanda Investigational Site
Berlin, 10117
Vanda Investigational Site
Hamburg, 20253
Vanda Investigational Site
Marburg, 35043
Vanda Investigational Site
Schwerin, 19053
Austria2 sites
Vanda Investigational Site
Innsbruck, 6020
Vanda Investigational Site
Vienna, 1090
About this study
Official title: 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.
- Being tested
- Tasimelteon, Placebo
- Medical subject headings
- Sleep Wake Disorders, Sleep Disorders, Circadian Rhythm, Chronobiology Disorders
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
TasimelteonDrug
oral capsule
PlaceboDrug
oral capsule
| Study group | Role | What they receive |
|---|---|---|
| Tasimelteon | Experimental | Not described Receives: Drug: Tasimelteon |
| Placebo | Placebo comparator | Not described Receives: Drug: Placebo |
What is being measured
The primary outcome is the main question the study is designed to answer.
Change in Sleep Onset over the treatment period, as measured by sleep diary.
Measured: 28 days
Secondary outcomes (3)
Change in nighttime objective sleep-wake parameters such as sleep time, as measured by actigraphy.
Measured: 28 days
Change in nighttime subjective sleep-wake parameters such as sleep time, as measured by sleep diary.
Measured: 28 days
Assessment of safety and tolerability of daily single dose of tasimelteon, as measured by spontaneous reporting of adverse events (AEs).
Measured: 28 days
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted3 Dec 2020
- Study start9 Dec 2020
- Primary completion4 Sep 2026
- Study completion4 Sep 2026
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (1)Papers the sponsor has linked to this study.
- Other trials for Sleep Wake DisordersStudies of the same condition, open and under way.
- More trials run by Vanda PharmaceuticalsThe 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 3
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Quadruple blind
- Who is masked
- Participant, Care provider, Investigator, Outcomes assessor
- Enrolment
- 43 participants (actual)
Sponsor and investigators
- Lead sponsor
- Vanda Pharmaceuticals
- Sponsor type
- Industry (pharma, biotech, devices)
- Responsible party
- Sponsor
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT04652882
- Sponsor's protocol ID
- VP-VEC-162-3502
- Status last verified
- Oct 2026
- First submitted
- 19 Nov 2020
- Last updated
- 9 Oct 2026
- Results posted
- No
- FDA-regulated drug
- Yes
- FDA-regulated device
- No
- Individual data sharing
- No
Publications
Smieszek SP, Kaden AR, Johnson CE, Brzezynski JL, Xiao C, Polymeropoulos CM, Birznieks G, Emsellem HA, Polymeropoulos MH. Case report: A patient with Delayed Sleep-Wake Phase Disorder and Optic Nerve Hypoplasia treated with tasimelteon: a case study. Front Neurosci. 2023 Nov 14;17:1287514. doi: 10.3389/fnins.2023.1287514. eCollection 2023.
PubMed 38033548
Study at a glance
From the registry record, last updated by the sponsor on 9 Oct 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- A Multicenter, Double-blind, Randomized Study to Evaluate the Effects of Tasimelteon vs. Placebo in Participants With Delayed Sleep-Wake Phase Disorder (DSWPD)
- ClinicalTrials.gov ID
- NCT04652882
- Acronym / sponsor ID
- VP-VEC-162-3502
- Phase
- Phase 3
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 43 participants (actual)
- Lead sponsor
- Vanda PharmaceuticalsIndustry (pharma, biotech, devices)
- Study start
- 9 Dec 2020 (actual)
- Primary completion
- 4 Sep 2026 (actual)
- Study completion
- 4 Sep 2026 (actual)
- First posted
- 3 Dec 2020 (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.
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 design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Quadruple blind (participant, care provider, investigator, outcomes assessor)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Tasimelteon | Experimental | Drug: Tasimelteon |
| Placebo | Placebo comparator | Drug: Placebo |
Who may qualify
- Ages
- 18 to 75 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (4 listed)
- 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.
Key exclusion criteria (5 listed)
- 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.
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 |
|---|---|---|
| Tasimelteonoral capsule | Drug | Tasimelteon |
| Placebooral capsule | Drug | Placebo |
Primary outcome
Change in Sleep Onset over the treatment period, as measured by sleep diary.
Time frame: 28 days
3 secondary outcomes
Change in nighttime objective sleep-wake parameters such as sleep time, as measured by actigraphy.
Time frame: 28 days
Change in nighttime subjective sleep-wake parameters such as sleep time, as measured by sleep diary.
Time frame: 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
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 9 Oct 2026.
- Derived from this study: PubMed 38033548Smieszek SP, Kaden AR, Johnson CE, Brzezynski JL, Xiao C, Polymeropoulos CM, Birznieks G, Emsellem HA, Polymeropoulos MH. Case report: A patient with Delayed Sleep-Wake Phase Disorder and Optic Nerve Hypoplasia treated with tasimelteon: a case study. Front Neurosci. 2023 Nov 14;17:1287514. doi: 10.3389/fnins.2023.1287514. eCollection 2023.
- Individual participant dataSharing planned: No
Related trials for Sleep Wake Disorders
Recruiting
Addressing Nocturia in Older Women Utilizing Behavioral Sleep Intervention and Brief Mindfulness
Nocturia, Insomnia
Recruiting
Investigation of the Effects of Sleep Deprivation on Itch and Pain Sensitivity
Histamine, Cowhage
RecruitingObservational study
Locus Coeruleus and CCHS (Congenital Central Hypoventilation Syndrome)
Ondine Syndrome (Congenital Central Hypoventilation Syndrome)
Not yet recruiting
A Transdiagnostic Sleep Health Intervention for Veterans With PTSD
Stress Disorders, Post-Traumatic, Sleep Initiation and Maintenance Disorders
RecruitingObservational study
Development and Validation of a Multimodal Deep Learning Model Using Peripheral Oxygen Saturation and Ballistocardiography Signals for Predicting Apnea-Hypopnea Index in Obstructive Sleep Apnea
Obstructive Sleep Apnea
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.
17 sites in 3 countries: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Phase 3 study testing Tasimelteon in people with Sleep Wake Disorders and Sleep Disorders, Circadian Rhythm, run by Vanda Pharmaceuticals at 17 sites in 3 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 4 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 9 Oct 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 17 sites in United States, Germany, Austria. 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 phase mean?
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 in Sleep Onset over the treatment period, as measured by sleep diary. (time frame: 28 days). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT04652882, which also lists 1 linked publication.
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 9 Oct 2026.