NCT06874855 · University of California, San Francisco
Lemborexant in Delayed Sleep Phase Syndrome
What this study is about
The purpose of the study is to evaluate whether Lemborexant is more effective than placebo in shortening sleep onset latency in patients with delayed sleep phase syndrome (both type 1 and type 2). This will be tracked using sleep logs as well as actigraphy.
View original scientific description
The purpose of the study is to evaluate whether Lemborexant is more effective than placebo in shortening sleep onset latency in patients with delayed sleep phase syndrome (both type 1 and type 2). This will be tracked using sleep logs as well as actigraphy. In this 2-year study, the investigators will examine if Lemborexant administered 5-10 mg nightly taken at desired bedtime (at least 2 hours prior to self-reported sleep onset habitual time) can improve the symptoms of Delayed Sleep Phase Syndrome.
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
- \- Participants will be required to be 18 years of age or older and have delayed sleep phase syndrome (DSPS). Questionnaires will be used to identify potential confounders and to confirm a potential diagnosis of DSPS based on ICSD3 criteria: a) Sleep is delayed by two hours or more beyond what is considered an acceptable or conventional bedtime for the subject (their desired bedtime). b) Subjects not able to fall asleep if trying to sleep before the later bedtime; c) This is interfering with their wishes/having a social impact. Concomitant medications will be allowed, though dosages will be required to remain fixed throughout participation in the study. The participant also needs to be willing and able to comply with all aspects of the protocol.
Exclusion criteria
- Clinically significant depression (PHQ-9 score of 10 or more), anxiety disorder (GAD- 7 score of 10 or more), substance use disorder, any other sleep disorder, or any medical disorder/therapy that could interfere with the trial
- Use of medications with significant effects on sleep-wake function (insomnia therapies, stimulants)- unless they are discontinued at least 5 half-lives prior to study participation. Non-sedative antidepressants or SSRI will be allowed if at a stable dose in the absence of concomitant severe depression or severe anxiety.
- Use of CYP3A inhibitors and CYP3A inducers, at least 1 week (or five half-lives, whichever is longer) prior to the first day of the baseline phase.
- Pregnancy (verified by urine pregnancy test on visits 1, 2, and 3) or plan to become pregnant in the next 3 months or currently breastfeeding.
- Shift workers or subjects working unusual hours.
- Transmeridian travel across more than 3 time zones 4 weeks prior to the screening phase.
- Transmeridian travel across more than 2 time zones during this trial (including the screening phase).
- Having a positive drug test or being unwilling to refrain from using illegal drugs or marijuana during this trial.
- Any clinically abnormal symptom or organ impairment found by medical history at Screening or Baseline and physical examinations, vital signs, or laboratory test results that require medical treatment.
- Impaired liver function (values for enzymes aspartate transaminase (AST) and alanine transaminase (ALT) \> 1.5 times the Upper Limit of Normal).
- Known to be human immunodeficiency virus positive.
Where
- San Francisco, California
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 Jun 5, 2026 · Source of record for eligibility and locations