OSAPhase 1/2LOSALATNCT05763329
Effects of Lemborexant as a Treatment for Moderate-to-severe OSA Patients With Low Arousal Threshold
A Phase 1/2 study testing Lemborexant 5 MG Oral Tablet [Dayvigo] Day 1 and Lemborexant 5 MG Oral Tablet [Dayvigo] Day 2 in people with OSA, run by Chulalongkorn University at 1 site in Thailand.
Trial summary
The goal of this randomized, placebo-controlled, double-blind, crossover trial (1-week wash out period) is to compare 1 night of 5 mg Lemborexant to placebo administered before sleep in 10 moderate to severe OSA patients with low arousal threshold The main questions it aims to answer are: 1. Read more about this study
- Who is it for?
- Ages 18 to 65 years
- Conditions the study is for
- OSA
- What is being tested?
- Lemborexant 5 MG Oral Tablet [Dayvigo] Day 1 and Lemborexant 5 MG Oral Tablet [Dayvigo] Day 2
- Type of treatment
- Pill or oral medicine
- Could I receive a placebo?
- Yes, some participants may receive a placebo
- How many people
- 10 participants
- Where
- 1 siteThailand
- Study dates
- 1 Feb 2023to 30 Jun 2025
- Phase
- Phase 1/2
- 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 65 years
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- Untreated OSA patient 18 - 65 years of age(49)
- AHI ≥15 events/h of sleep (moderate to severe)(23, 49)
- Low arousal threshold was defined using previously recommended criteria which allocated a score of 1 to each criterion that was satisfied: (apnea-hypopnea index, <30 events per hour) + (nadir oxygen saturation as measured by pulse oximetry >82.5%) + (fraction of hypopneas >58.3%). A score of 2 or above defined a low arousal threshold(50) (low arousal threshold defined as esophageal pressure values are 0 to -15 cmH2O)(27)
Who cannot join
- Previous allergy or adverse effects with Lemborexant or other sedatives - Taking any medication that affects sleep or other variable measured in this study - Pregnant or nursing mothers - Respiratory disorders other than OSA - Comorbid disease of poor controlled or resistant hypertension, uncontrolled cardiovascular or cerebrovascular disease
- Using CPAP or other dental devices
- Unable to tolerate equipment in this study
Trial locations and contacts
1 site in 1 country.
About this study
Official title: A Randomized, Double-blind, Placebo-Controlled Trial on the Effects of Lemborexant as a Treatment for Moderate-to-severe OSA Patients With Low Arousal Threshold
The goal of this randomized, placebo-controlled, double-blind, crossover trial (1-week wash out period) is to compare 1 night of 5 mg Lemborexant to placebo administered before sleep in 10 moderate to severe OSA patients with low arousal threshold
The main questions it aims to answer are:
Read more
- The effect of Lemborexant on apnea/hypopnea index (AHI) in moderate-to-severe OSA patients with low arousal threshold.
- The effect of Lemborexant on the following parameters in moderate-to-severe OSA patients with low arousal threshold.
- Arousal threshold
- Mean and nadir oxygen saturation
- Sleep latency
- Sleep efficiency
- Wake after sleep onset (WASO)
- Percentage of time spent in NREM stage 1-3 and REM stage
- Stanford Sleepiness Scale Questionnaire in the morning
- The Oxford Sleep Resistance Test (OSLER) test
Participants will
- complete two overnight in-laboratory polysomnography (1-week washout)
- complete the OSLER test in the morning of the two overnight test
Researchers will compare with the placebo group to see if there is a difference in AHI
Read the detailed description
Research Design A randomized, placebo-controlled, double-blind, crossover trial (1-week wash out period) comparing 1 night of 5 mg Lemborexant to placebo administered before sleep.
Research Methodology Participants A total of 10 moderate to severe OSA patients with low arousal threshold are randomized 1:1 to either Lemborexant or placebo. The participants will complete two overnight in-laboratory polysomnography (1-week washout). Next-morning alertness will also be assessed using OSLER test, respectively.
Inclusion criteria
Eligible, healthy individuals with all the followings:
- Untreated OSA patient 18 - 65 years of age
- AHI ≥15 events/h of sleep
- Low arousal threshold
Study protocol All patients who were previously diagnosed with moderate to severe obstructive sleep apnea from baseline polysomnography with a low arousal threshold will be enrolled.
The patients will be subsequently randomized 1:1 to one of the two treatment sequences. Participants will complete two overnight sleep studies and cross-over with 1-week wash-out period. Patients will receive either Lemborexant 5 mg per day or placebo prior 5 minutes before lights-out.
During this 2-night polysomnography, sleep parameters will be analyzed including AHI, mean and nadir oxygen indices, sleep latency, sleep efficiency, wake after sleep onset (WASO), and percentage of time spent in NREM, stage 1-3 and REM stage. The OSLER test to define vigilance will be obtained on the following morning.
- Conditions
- OSA
- Being tested
- Lemborexant 5 MG Oral Tablet [Dayvigo] Day 1, Lemborexant 5 MG Oral Tablet [Dayvigo] Day 2, Placebo Day 1, Placebo Day 2
- Keywords
- Apnea/Hypopnea Index (AHI), Lemborexant, Obstructive Sleep Apnea (OSA), Low Arousal Threshold, Polysomnography
- Medical subject headings
- Apnea, Sleep Apnea, Obstructive
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Lemborexant 5 MG Oral Tablet [Dayvigo] Day 1Drug
Patients will receive Lemborexant 5 mg per day on the first day of sleep test
Lemborexant 5 MG Oral Tablet [Dayvigo] Day 2Drug
Patients will receive Lemborexant 5 mg per day on the second day of sleep test
Placebo Day 1Drug
Patients will receive placebo on the first day of sleep test
Placebo Day 2Drug
Patients will receive placebo on the second day of sleep test
| Study group | Role | What they receive |
|---|---|---|
| Lemborexant | Experimental | Patients will receive two treatment sequences. Participants will complete two overnight sleep studies and cross-over with 1-week wash-out period The participants will receive Lemborexant 5 mg per day 5 minutes before lights-out for one dose for the first overnight sleep test of the experiment. After 1 week wash-out period, the participants will cross to the placebo arm and receive placebo 5 minutes before lights-out for one dose for the second overnight sleep test of the experiment. Receives: Drug: Lemborexant 5 MG Oral Tablet [Dayvigo] Day 1; Drug: Placebo Day 2 |
| Placebo | Placebo comparator | Patients will receive two treatment sequences. Participants will complete two overnight sleep studies and cross-over with 1-week wash-out period The participants will receive placebo 5 minutes before lights-out for one dose for the first overnight sleep test of the experiment. After 1 week wash-out period, the participants will cross to the Lemborexant arm and receive Lemborexant 5 mg per day 5 minutes before lights-out for one dose for the second overnight sleep test of the experiment. Receives: Drug: Lemborexant 5 MG Oral Tablet [Dayvigo] Day 2; Drug: Placebo Day 1 |
What is being measured
The primary outcome is the main question the study is designed to answer.
apnea/hypopnea index (AHI)
AHI
Measured: through study completion, one week
Secondary outcomes (6)
Mean and nadir oxygen saturation
Measured: through study completion, one week
Sleep latency (Time the patients fall asleep)
Time spent from light out to the first 20 consecutive 30-second period of nonwakefulness (minutes)
Measured: through study completion, one week
Sleep efficiency (Time the patients actually sleep through out the experiment)
Time the patient sleep per time in bed which is the total sleep time per time from light out until light on (total record time (TRT) (8 hours) (minutes)
Measured: through study completion, one week
Wake after sleep onset (WASO)
Total time of wakefulness after initial sleep onset until light on
Measured: through study completion, one week
Percentage of time spent in NREM stage 1-3 and REM stage
Measured: through study completion, one week
The Oxford Sleep Resistance Test (OSLER) test
Measured: through study completion, one week
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted10 Mar 2023
- Study start1 Feb 2023
- Primary completion28 Feb 2025
- Study completion30 Jun 2025
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for OSAStudies of the same condition, open and under way.
- More trials run by Chulalongkorn UniversityThe 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 1/2
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Crossover
- Model description
- The patients will be subsequently randomized 1:1 to one of the two treatment sequences. Participants will complete two overnight sleep studies and cross-over with 1-week wash-out period. Patients will receive either Lemborexant 5 mg per day or placebo prior 5 minutes before lights-out. Time of lights out was calculated from the median usual bedtime for each participant from the most recent 5 days (± 1 hour) and was kept constant between the two study nights. During this 2-night polysomnography, sleep parameters will be analyzed. The OSLER test to define vigilance will be obtained on the following morning.
- Masking
- Double blind
- Who is masked
- Participant, Care provider
- Enrolment
- 10 participants (actual)
Sponsor and investigators
- Lead sponsor
- Chulalongkorn University
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor
- Investigators
- Sarocha Vivatvakin, MD, Principal investigator, Department of Medicine, Faculty of Medicine, Chulalongkorn University
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT05763329
- Sponsor's protocol ID
- 218/64
- Acronym
- LOSALAT
- Status last verified
- Feb 2025
- First submitted
- 9 Feb 2023
- Last updated
- 17 Sep 2025
- Results posted
- No
- Data monitoring committee
- Yes
- FDA-regulated drug
- Yes
- FDA-regulated device
- No
- Individual data sharing
- No
Study at a glance
From the registry record, last updated by the sponsor on 17 Sep 2025. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- A Randomized, Double-blind, Placebo-Controlled Trial on the Effects of Lemborexant as a Treatment for Moderate-to-severe OSA Patients With Low Arousal Threshold
- ClinicalTrials.gov ID
- NCT05763329
- Acronym / sponsor ID
- LOSALAT / 218/64
- Conditions
- OSA
- Keywords
- Apnea/Hypopnea Index (AHI), Lemborexant, Obstructive Sleep Apnea (OSA), Low Arousal Threshold, Polysomnography
- Phase
- Phase 1/2
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 10 participants (actual)
- Lead sponsor
- Chulalongkorn UniversityUniversity, hospital or other
- Study start
- 1 Feb 2023 (actual)
- Primary completion
- 28 Feb 2025 (actual)
- Study completion
- 30 Jun 2025 (actual)
- First posted
- 10 Mar 2023 (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.
The goal of this randomized, placebo-controlled, double-blind, crossover trial (1-week wash out period) is to compare 1 night of 5 mg Lemborexant to placebo administered before sleep in 10 moderate to severe OSA patients with low arousal threshold
The main questions it aims to answer are:
- The effect of Lemborexant on apnea/hypopnea index (AHI) in moderate-to-severe OSA patients with low arousal threshold.
- The effect of Lemborexant on the following parameters in moderate-to-severe OSA patients with low arousal threshold.
- Arousal threshold
- Mean and nadir oxygen saturation
- Sleep latency
- Sleep efficiency
- Wake after sleep onset (WASO)
- Percentage of time spent in NREM stage 1-3 and REM stage
- Stanford Sleepiness Scale Questionnaire in the morning
- The Oxford Sleep Resistance Test (OSLER) test
Participants will
- complete two overnight in-laboratory polysomnography (1-week washout)
- complete the OSLER test in the morning of the two overnight test
Researchers will compare with the placebo group to see if there is a difference in AHI
Detailed description
Research Design A randomized, placebo-controlled, double-blind, crossover trial (1-week wash out period) comparing 1 night of 5 mg Lemborexant to placebo administered before sleep.
Research Methodology Participants A total of 10 moderate to severe OSA patients with low arousal threshold are randomized 1:1 to either Lemborexant or placebo. The participants will complete two overnight in-laboratory polysomnography (1-week washout). Next-morning alertness will also be assessed using OSLER test, respectively.
Inclusion criteria
Eligible, healthy individuals with all the followings:
- Untreated OSA patient 18 - 65 years of age
- AHI ≥15 events/h of sleep
- Low arousal threshold
Study protocol All patients who were previously diagnosed with moderate to severe obstructive sleep apnea from baseline polysomnography with a low arousal threshold will be enrolled.
The patients will be subsequently randomized 1:1 to one of the two treatment sequences. Participants will complete two overnight sleep studies and cross-over with 1-week wash-out period. Patients will receive either Lemborexant 5 mg per day or placebo prior 5 minutes before lights-out.
During this 2-night polysomnography, sleep parameters will be analyzed including AHI, mean and nadir oxygen indices, sleep latency, sleep efficiency, wake after sleep onset (WASO), and percentage of time spent in NREM, stage 1-3 and REM stage. The OSLER test to define vigilance will be obtained on the following morning.
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Crossover
- Masking
- Double blind (participant, care provider)
- Number of arms
- 2
- Model description
- The patients will be subsequently randomized 1:1 to one of the two treatment sequences. Participants will complete two overnight sleep studies and cross-over with 1-week wash-out period. Patients will receive either Lemborexant 5 mg per day or placebo prior 5 minutes before lights-out. Time of lights out was calculated from the median usual bedtime for each participant from the most recent 5 days (± 1 hour) and was kept constant between the two study nights. During this 2-night polysomnography, sleep parameters will be analyzed. The OSLER test to define vigilance will be obtained on the following morning.
| Arm | Type | Receives |
|---|---|---|
| Lemborexant | Experimental | Drug: Lemborexant 5 MG Oral Tablet [Dayvigo] Day 1, Drug: Placebo Day 2Patients will receive two treatment sequences. Participants will complete two overnight sleep studies and cross-over with 1-week wash-out period The participants will receive Lemborexant 5 mg per day 5 minutes before lights-out for one dose for the first overnight sleep test of the experiment. After 1 week wash-out period, the participants will cross to the placebo arm and receive placebo 5 minutes before lights-out for one dose for the second overnight sleep test of the experiment. |
| Placebo | Placebo comparator | Drug: Lemborexant 5 MG Oral Tablet [Dayvigo] Day 2, Drug: Placebo Day 1Patients will receive two treatment sequences. Participants will complete two overnight sleep studies and cross-over with 1-week wash-out period The participants will receive placebo 5 minutes before lights-out for one dose for the first overnight sleep test of the experiment. After 1 week wash-out period, the participants will cross to the Lemborexant arm and receive Lemborexant 5 mg per day 5 minutes before lights-out for one dose for the second overnight sleep test of the experiment. |
Who may qualify
- Ages
- 18 to 65 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (3 listed)
- Untreated OSA patient 18 - 65 years of age(49)
- AHI ≥15 events/h of sleep (moderate to severe)(23, 49)
- Low arousal threshold was defined using previously recommended criteria which allocated a score of 1 to each criterion that was satisfied: (apnea-hypopnea index, <30 events per hour) + (nadir oxygen saturation as measured by pulse oximetry >82.5%) + (fraction of hypopneas >58.3%). A score of 2 or above defined a low arousal threshold(50) (low arousal threshold defined as esophageal pressure values are 0 to -15 cmH2O)(27)
Key exclusion criteria (3 listed)
- Previous allergy or adverse effects with Lemborexant or other sedatives - Taking any medication that affects sleep or other variable measured in this study - Pregnant or nursing mothers - Respiratory disorders other than OSA - Comorbid disease of poor controlled or resistant hypertension, uncontrolled cardiovascular or cerebrovascular disease
- Using CPAP or other dental devices
- Unable to tolerate equipment in this study
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 |
|---|---|---|
| Lemborexant 5 MG Oral Tablet [Dayvigo] Day 1Patients will receive Lemborexant 5 mg per day on the first day of sleep test | Drug | Lemborexant |
| Lemborexant 5 MG Oral Tablet [Dayvigo] Day 2Patients will receive Lemborexant 5 mg per day on the second day of sleep test | Drug | Placebo |
| Placebo Day 1Patients will receive placebo on the first day of sleep test | Drug | Placebo |
| Placebo Day 2Patients will receive placebo on the second day of sleep test | Drug | Lemborexant |
Primary outcome
apnea/hypopnea index (AHI)
Time frame: through study completion, one week
AHI
6 secondary outcomes
Mean and nadir oxygen saturation
Time frame: through study completion, one week
Sleep latency (Time the patients fall asleep)
Time frame: through study completion, one week
Sleep efficiency (Time the patients actually sleep through out the experiment)
Time frame: through study completion, one week
Wake after sleep onset (WASO)
Time frame: through study completion, one week
Percentage of time spent in NREM stage 1-3 and REM stage
Time frame: through study completion, one week
The Oxford Sleep Resistance Test (OSLER) test
Time frame: through study completion, one week
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 17 Sep 2025.
- Individual participant dataSharing planned: No
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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.
Sarocha Vivatvakin, MD principal investigator
Department of Medicine, Faculty of Medicine, Chulalongkorn University
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Phase 1/2 study testing Lemborexant 5 MG Oral Tablet [Dayvigo] Day 1 and Lemborexant 5 MG Oral Tablet [Dayvigo] Day 2 in people with OSA, run by Chulalongkorn University at 1 site in Thailand.
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 3 inclusion and 3 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 17 Sep 2025. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in Thailand. 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 combined phase mean?
Phase 1 studies test a treatment in a small group of people for the first time or in a new way, mainly to check safety and find the right dose.
Phase 2 studies give the treatment to a larger group to see whether it has the intended effect and to keep checking safety.
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?
apnea/hypopnea index (AHI) (time frame: through study completion, one week). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
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 17 Sep 2025.