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Obstructive Sleep ApneaPhase 2ExPRESSIONNCT04875364

Do Endotypes Predict Response and Sequelae in OSA Patients

A Phase 2 study testing Eszopiclone, Supplemental Oxygen and Continuous Positive Airway Pressure (CPAP) in people with Obstructive Sleep Apnea and Sleep Apnea, run by University of California, San Diego at 1 site in United States.

Completed

Finished. The study has ended and is not enrolling. Results may be posted on the official record.

Official record
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Trial summary

This study will investigate why some people have Obstructive Sleep Apnea (OSA) and how the underlying cause may relate to OSA manifestations (including sleepiness and high blood pressure) and response to different therapeutic approaches (ie CPAP, eszopiclone, and supplemental oxygen). Read more about this study

Who is it for?
Ages 21 to 65 years
What is being tested?
Eszopiclone, Supplemental Oxygen and Continuous Positive Airway Pressure (CPAP)
Type of treatment
Medical device
Could I receive a placebo?
No, everyone receives an active treatment
How many people
233 participants
Where
1 siteUnited States
Study dates
1 Aug 2020to 11 Feb 2026
Phase
Phase 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 21 to 65 years
  • All sexes
  • No healthy volunteers
  • Adult, Older adult

Who may be able to join

  • Ages 21-65 years old
  • Men and women with a physician diagnosis of OSA (or strongly suspected to have sleep apnea - * see below)
  • BMI 20 - 35 kg/m2

Who cannot join

  • Pregnancy (current or planned)
  • Nursing
  • Inability to provide self-consent or complete study procedures, such as questionnaires that are only available/validated in English.
  • Already on effective therapy and adherent to treatment for OSA
  • Other known untreated sleep fragmenting disorder, such as periodic limb movement disorder, or narcolepsy
  • Circadian rhythm disorder
Show all 24Show fewer
  • Unrevascularized coronary artery disease, angina, prior heart attack or stroke, congestive heart failure
  • Uncontrolled hypertension (systolic blood pressure >160, diastolic blood pressure >95)
  • Chronic lung disease requiring the use of supplemental oxygen, or with evidence of hypercapnia due to obstructive lung disease.
  • Presence of tracheostomy
  • Hospitalization within the past 90 days
  • Prior peptic ulcer disease, esophageal varices, or gastrointestinal bleeding (< 5 years)
  • Prior gastric bypass surgery
  • Chronic liver disease or end-stage kidney disease
  • Active cancer
  • Allergy to any of the study drug
  • Regular use of medications known to affect control of breathing (opioids, sedatives/hypnotics including benzodiazepines, theophylline)
  • Chronically using study drug (Eszopiclone)
  • Active illicit substance use
  • Alcohol use of >1 standard drink/night for women or >2 standard drinks/night for men nightly alcohol use
  • Active smoking or vaping within the past 6 months
  • Psychiatric disease, other than controlled depression/anxiety
  • Prisoners
  • Subjects who are strongly suspected to have sleep apnea will be offered an overnight home sleep apnea test (HSAT) to verify OSA diagnosis.

Trial locations and contacts

1 site in 1 country.

United States1 site
  • Altman Clinical and Translational Research Institute Building

    La Jolla, California, 92037

Other trials in United States

About this study

This study will investigate why some people have Obstructive Sleep Apnea (OSA) and how the underlying cause may relate to OSA manifestations (including sleepiness and high blood pressure) and response to different therapeutic approaches (ie CPAP, eszopiclone, and supplemental oxygen). Understanding why someone has OSA could affect how best to treat that individual, but may also have an impact on what problems the disease might cause.

Being tested
Eszopiclone, Supplemental Oxygen, Continuous Positive Airway Pressure (CPAP)
Keywords
sleep, sleep apnea, OSA, obstructive sleep apnea, lunesta, cpap, endotype, Eszopiclone
Medical subject headings
Sleep Apnea, Obstructive, Sleep Apnea Syndromes, Sleep Wake Disorders, Microcephaly, Primary Autosomal Recessive, 6

What participants receive

What participants receive. In a randomised study each person is assigned to one group by chance.

  • EszopicloneDrug

    Also called Lunesta

    2mg of Eszopiclone just before going to sleep.

  • Supplemental OxygenOther

    Constant oxygen flow at 4 Liters per minutes for the duration of time in bed via nasal cannula.

  • Continuous Positive Airway Pressure (CPAP)Device

    A standard CPAP device will be provided using the settings as prescribed by the treating physician.

Study groups in NCT04875364
Study groupRoleWhat they receive
Early PAP StartExperimentalAfter two initial baseline overnight studies, and two experimental overnight studies during which subjects will receive Eszopiclone (2mg before bedtime) or oxygen (4L/min via nasal cannula for the duration of the time in bed) in random order, subjects will be set up with a loaner CPAP for 8 weeks to initiate therapy right away.
Receives: Drug: Eszopiclone; Other: Supplemental Oxygen; Device: Continuous Positive Airway Pressure (CPAP)
Usual PAP StartExperimentalAfter two initial baseline overnight studies, and two experimental overnight studies during which subjects will receive Eszopiclone (2mg before bedtime) or oxygen (4L/min via nasal cannula for the duration of the time in bed) in random order, subjects will remain untreated until they are set up with their clinically prescribed CPAP (typically takes about 8 weeks).
Receives: Drug: Eszopiclone; Other: Supplemental Oxygen

What is being measured

The primary outcome is the main question the study is designed to answer.

  1. Psychomotor Vigilance Test

    A 10-minutes, computerized reaction test asking subject to press a button every time a prompt appears. Faster times indicate better reactions and higher alertness.

    Measured: 8 weeks

  2. Endothelial Dysfunction

    Using a device called EndoPAT for a non-invasive bloodflow measure before, during, and after 5-minutes of occlusion to one arm. Differences in EndoPAT results will be compared between treatments.

    Measured: 8 weeks

Secondary outcomes (14)
  1. Neurocognitive Assessment: NIH Toolbox

    This battery yields three composite scores: overall cognitive function, crystallized cognition and fluid cognition. The two tests of "crystallized cognition" are less sensitive to acquired brain dysfunction and reflect past learning experiences (Oral Reading Recognition and Picture Vocabulary). The five tests of "fluid cognition" assess multiple cognitive domains that are vulnerable to acquired brain dysfunction (i.e., Picture Sequence Memory Task = episodic memory, Dimensional Change Card Sort Task = executive function/flexibility, Pattern Comparison Task = processing speed, Flanker Inhibitory Control and Attention Task = executive function/inhibitory control, and List Sorting Task = working memory).

    Measured: 8 weeks

  2. Epworth Sleepiness Scale (ESS)

    A self-administered questionnaire with 8 questions. Respondents are asked to rate, on a 4-point scale (0-3), their usual chances of dozing off or falling asleep while engaged in eight different activities. The ESS score (the sum of 8 item scores, 0-3) can range from 0 to 24. The higher the ESS score, the higher that person's average sleep propensity in daily life (ASP), or their 'daytime sleepiness'.

    Measured: 8 weeks

  3. Pittsburgh Sleep Quality Index (PSQI)

    A 19-item, self-rated questionnaire designed to measure sleep quality and disturbance over the past month. The sleep component scores are summed to yield a total score ranging from 0 to 21 with the higher total score (referred to as global score) indicating worse sleep quality.

    Measured: 8 weeks

  4. Insomnia Severity Index (ISI)

    A 7-item self-report form to assess insomnia severity. Total score categories: 0-7 = No clinically significant insomnia, 8-14 = Subthreshold insomnia, 15-21 = Clinical insomnia (moderate severity), 22-28 = Clinical insomnia (severe).

    Measured: 8 weeks

  5. Richard's Campbell Sleep Questionnaire (RCSQ)

    A five-item self-report questionnaire that is used in order to assess perceived sleep depth, sleep latency (time to fall asleep), and number of awakenings, as well as sleep efficiency and quality. Each item is scored on a visual analog scale ranging from 0 mm to 100 mm, with higher scores representing better sleep. The mean score of the five items is known as the total score and represents the overall perception of sleep.

    Measured: 8 weeks

  6. Functional Assessment of Chronic Illness Therapy Fatigue Scale (FACIT-F)

    A 40-item questionnaire to assesses self-reported fatigue and its impact upon daily activities and function. The score ranges from 0 to 160 with greater values indicating better quality of life.

    Measured: 8 weeks

  7. Beck Depression Index-II

    The questionnaire assesses mental health (i.e. depression). Each of the 21 items are given weighted values corresponding to a symptom of depression and summed to give a single score. Total score of 0-13 is considered minimal range, 14-19 is mild, 20-28 is moderate, and 29-63 is severe.

    Measured: 8 weeks

  8. SF-36 Item Health Survey (SF-36)

    A set of 36 generic, coherent, and easily administered quality-of-life measures. Scoring consists of eight scaled scores, which are the weighted sums of the questions in their section. Each scale is directly transformed into a 0-100 scale on the assumption that each question carries equal weight. The lower the score the more disability.

    Measured: 8 weeks

  9. Brief Pain Inventory (Short Form)

    A 9 item self-administered questionnaire used to evaluate the severity of a patient's pain and the impact of this pain on the patient's daily functioning. The patient is asked to rate their worst, least, average, and current pain intensity, list current treatments and their perceived effectiveness, and rate the degree that pain interferes with general activity, mood, walking ability, normal work, relations with other persons, sleep, and enjoyment of life on a 10 point scale with 10 being the most pain.

    Measured: 8 weeks

  10. PROMIS (Patient-Reported Outcomes Measurement Information System) pain intensity

    A self-reported form to assess how much pain a person is feeling.

    Measured: 8 weeks

  11. Systolic Blood Pressure

    Measured at rest following standard guidelines.

    Measured: 8 weeks

  12. Diastolic Blood Pressure

    Measured at rest following standard guidelines.

    Measured: 8 weeks

  13. Patient's Assessment of Own Function Inventory (PAOF) questionnaire

    A subjective measure of cognitive function that asks participants to rate how often they experience difficulty in four areas: memory, language/communication, sensory-motor ability, and executive function with response options from 0 ("almost never") to 5 ("almost always").

    Measured: 8 weeks

  14. PROMIS (Patient-Reported Outcomes Measurement Information System) pain interference

    A self-reported measure the self-reported consequences of pain on relevant aspects of a person's life and may include the extent to which pain hinders engagement with social, cognitive, emotional, physical, and recreational activities.

    Measured: 8 weeks

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

  1. First posted6 May 2021
  2. Study start1 Aug 2020
  3. Primary completion11 Feb 2026
  4. Study completion11 Feb 2026

Resources

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 2
Primary purpose
Treatment
Allocation
Randomised
Intervention model
Parallel groups
Masking
None (open label)
Enrolment
233 participants (actual)
IDs, dates and publications
ClinicalTrials.gov ID
NCT04875364
Sponsor's protocol ID
201432
Acronym
ExPRESSION
Status last verified
Jun 2026
First submitted
27 Apr 2021
Last updated
18 Jun 2026
Results posted
No
Data monitoring committee
Yes
FDA-regulated drug
Yes
FDA-regulated device
No

Questions about this trial

What is this clinical trial studying?

A Phase 2 study testing Eszopiclone, Supplemental Oxygen and Continuous Positive Airway Pressure (CPAP) in people with Obstructive Sleep Apnea and Sleep Apnea, run by University of California, San Diego at 1 site in United States.

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 24 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 18 Jun 2026. 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 United States. 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. 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 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?

Psychomotor Vigilance Test (time frame: 8 weeks). The study lists 2 primary outcomes in all. 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 18 Jun 2026.

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