Lemborexant in Delayed Sleep Phase Syndrome

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.

NCT Number	NCT06874855
Lead Sponsor	University of California, San Francisco Collaborators: Eisai Co., Ltd., Stanford University
Conditions	Delayed Sleep Phase Syndrome
Enrollment	15 participants
Start Date	2023-03-13
Primary Completion	2027-05-31 (estimated)
Study Completion	2027-05-31 (estimated)
Updated on ClinicalTrials.gov	2026-06-05