Evaluating Tasimelteon for Delayed Sleep-Wake Phase Disorder

A Double-Blind, Randomized, Two-Period Crossover Study to Evaluate the Effects of Tasimelteon Vs. Placebo in Subjects with Delayed Sleep-Wake Phase Disorder (DSWPD) and the CRY1Δ11 Variant

Phase 3 Interventional Vanda Pharmaceuticals · NCT06701396

This study is testing if a new sleep medication called tasimelteon can help people with Delayed Sleep-Wake Phase Disorder who have a specific genetic variant improve their sleep patterns.

Quick facts

PhasePhase 3
Study typeInterventional
Enrollment60 (estimated)
Ages18 Years to 75 Years
SexAll
SponsorVanda Pharmaceuticals Industry-sponsored
Locations1 site (Çankaya, Ankara)
Trial IDNCT06701396 on ClinicalTrials.gov

What this trial studies

This clinical trial is a double-blind, randomized, two-period crossover study designed to assess the efficacy and safety of a single oral dose of tasimelteon compared to a placebo in individuals diagnosed with Delayed Sleep-Wake Phase Disorder (DSWPD) who also carry the CRY1Δ11 genetic variant. Participants will be monitored for improvements in their sleep patterns and overall circadian rhythm. The study aims to gather data on how tasimelteon affects sleep-wake cycles in this specific patient population.

Who should consider this trial

Good fit: Ideal candidates for this study are men and women aged 18 to 75 with a confirmed diagnosis of DSWPD and who are carriers of the CRY1Δ11 variant.

Not a fit: Patients who have had major surgery, trauma, or illness in the past 30 days, or who are pregnant or breastfeeding, may not benefit from this study.

Why it matters

Potential benefit: If successful, this study could provide a new treatment option for patients suffering from DSWPD, potentially improving their quality of life.

How similar studies have performed: Other studies have explored treatments for sleep disorders, but the specific approach of using tasimelteon in this genetic context is relatively novel.

Eligibility criteria

Show full inclusion / exclusion criteria
Inclusion Criteria:

* Ability and acceptance to provide written informed consent.
* A confirmed clinical diagnosis of Delayed Sleep-Wake Phase Disorder (DSWPD).
* Carrier of CRY1Δ11 variant.
* Men or women between 18 - 75 years, inclusive.
* Body Mass Index (BMI) of ≥ 18 and ≤ 40 kg/m\^2.

Exclusion Criteria:

* 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 this trial is running

Çankaya, Ankara

Study contacts

How to participate

  1. Review the eligibility criteria above with your treating physician.
  2. Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
  3. Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.
Conditions Sleep Wake DisordersSleep Disorders, Circadian RhythmChronobiology DisordersGene Mutations and Other Alterations Nec
Last reviewed 2026-06-09 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.