Obstructive Sleep ApneaPhase 2NCT05953610
Endotypic Traits and Obstructive Sleep Apnea Surgery
A Phase 2 study testing Acetazolamide 500 MG QHS and Eszopiclone 3 mg QHS in people with Obstructive Sleep Apnea, run by University of California, Los Angeles at 2 sites in United States.
Trial summary
This study will examine factors associated with outcomes after soft palate surgery and medications (acetazolamide, eszopiclone) that may treat other potential causes of obstructive sleep apnea (loop gain, arousal threshold). Read more about this study
- Who is it for?
- Ages 21 years and older
- Conditions the study is for
- Obstructive Sleep Apnea
- What is being tested?
- Acetazolamide 500 MG QHS and Eszopiclone 3 mg QHS
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 150 participants
- Where
- 2 sitesUnited States
- Study dates
- 7 Jan 2024to 31 Aug 2028
- Phase
- Phase 2
- Are there results?
- Not yet: the study is under way
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 years and older
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- age ≥21 years;
- moderate to severe OSA (obstructive AHI ≥ 15 events/hour);
- central/mixed apnea index <5 events/hour;
- intolerance of positive airway pressure (defined as use < 2 hours/night at least 5 nights/week);
- intolerance or poor candidate for oral appliance;
- participant has provided informed consent for palate surgery as part of their standard of care;
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- tonsil size 0-2+ (without markedly enlarged tonsils that have high surgical success rates);
- DISE without evidence of complete tongue-related obstruction (reflecting poorer results with isolated palate surgery);
- medications stable for ≥2 months;
- body mass index <35 kg/m2;
- absence of uncontrolled nasal obstruction;
- no prior pharyngeal surgery other than tonsillectomy;
- no neurologic, cardiac or pulmonary disorders;
- absence of psychiatric disorder except for treated depression or mild anxiety;
- no co-existing sleep disorder, such as narcolepsy, chronic insomnia, or restless legs syndrome;
- no use of hypnotics, anxiolytics, stimulants, or sedating antidepressants;
- no near-miss or prior motor vehicle crash due to sleepiness in past 12 months; and
- <3 caffeinated beverages daily.
Who cannot join
- history of allergic reaction to either of the study drugs;
- subjects with prior serious allergic reaction (such as Stevens-Johnson syndrome) to sulfonamides;
- subjects with a history of hypersensitivity to either of the two study drugs;
- subjects who are on high-dose aspirin therapy due to risk of severe metabolic acidosis;
- subjects with severe kidney disease or severe liver disease;
- subjects with a history of electrolyte imbalance or adrenal insufficiency (due to risks related to acetazolamide);
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- subjects on ketoconazole or other strong CYP3A4 inhibitors (these will increase eszopiclone blood levels);
- pregnancy; and
- alcohol or substance abuse.
Trial locations and contacts
2 sites in 1 country. Contact the study team or a site near you to ask about taking part.
United States2 sites, 2 recruiting
- Recruiting
UCLA Santa Monica Medical Center
Santa Monica, California, 90401
Eric Kezirian, MD, MPH
Eric Kezirian, MD, MPH
- Not yet recruiting
UCLA Westwood
Westwood, Los Angeles, California, 90095
Eric Kezirian, MD, MPH
Eric Kezirian, MD, MPH
About this study
This study will examine factors associated with outcomes after soft palate surgery and medications (acetazolamide, eszopiclone) that may treat other potential causes of obstructive sleep apnea (loop gain, arousal threshold).
Read the detailed description
This is a prospective cohort (observational) study of 150 participants with moderate to severe obstructive sleep apnea (OSA) unable to tolerate positive airway pressure who are undergoing drug-induced sleep endoscopy (DISE), including measurement of upper airway closing pressure (Pclose), and tissue-repositioning soft palate surgery. Before and 6 months after surgery, the investigators will measure OSA severity (apnea-hypopnea index) with sleep studies (polysomnograms). Using a recently-validated polysomnography-based signal processing algorithm, the investigators will systematically assess the underlying mechanisms of OSA (traits) and airflow shape (consistent with palate obstruction). The expected 90 participants without resolution of OSA after surgery (surgery failures) will participate in an experimental randomized crossover study of acetazolamide (1 month) and acetazolamide/eszopiclone combination (1 month). Polysomnograms will be performed with each treatment, with algorithm-based determination of traits.
- Conditions
- Obstructive Sleep Apnea
- Being tested
- Acetazolamide 500 MG QHS, Eszopiclone 3 mg QHS
- Keywords
- surgery, loop gain, arousal threshold
- Medical subject headings
- Sleep Apnea, Obstructive
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Acetazolamide 500 MG QHSDrug
Acetazolamide
Eszopiclone 3 mg QHSDrug
Eszopiclone
| Study group | Role | What they receive |
|---|---|---|
| Acetazolamide | Experimental | Treatment with acetazolamide 500 mg nightly for 1 month. Receives: Drug: Acetazolamide 500 MG QHS |
| Acetazolamide/Eszopiclone | Experimental | Treatment with acetazolamide 500 mg and eszopiclone 3 mg nightly for 1 month. Receives: Drug: Acetazolamide 500 MG QHS; Drug: Eszopiclone 3 mg QHS |
What is being measured
The primary outcome is the main question the study is designed to answer.
Apnea-hypopnea index
apneas plus hypopneas per hour of sleep
Measured: 6 months
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted20 Jul 2023
- Study start7 Jan 2024
- Primary completion31 Aug 2028 (estimated)
- Study completion31 Aug 2028 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Obstructive Sleep ApneaStudies of the same condition, open and under way.
- More trials run by University of California, Los AngelesThe 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 2
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Crossover
- Model description
- Prospective cohort study will include an anticipated 150 study participants undergoing soft palate surgery. The randomized crossover (interventional) study will include the anticipated 90 who do not achieve successful treatment of their obstructive sleep apnea with surgery.
- Masking
- None (open label)
- Enrolment
- 150 participants (estimated)
Sponsor and investigators
- Lead sponsor
- University of California, Los Angeles
- Sponsor type
- University, hospital or other
- Collaborators
- National Heart, Lung, and Blood Institute (NHLBI)
- Responsible party
- Principal investigator, Eric J. Kezirian, MD, MPH, University of California, Los Angeles
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT05953610
- Sponsor's protocol ID
- 1.0
- Other IDs
- R01HL160993
- Status last verified
- Jun 2026
- First submitted
- 8 May 2023
- Last updated
- 1 Jul 2026
- Results posted
- No
- Data monitoring committee
- Yes
- FDA-regulated drug
- Yes
- FDA-regulated device
- No
Study at a glance
From the registry record, last updated by the sponsor on 1 Jul 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Endotypic Traits and Obstructive Sleep Apnea Surgery
- ClinicalTrials.gov ID
- NCT05953610
- Acronym / sponsor ID
- 1.0
- Conditions
- Obstructive Sleep Apnea
- Keywords
- surgery, loop gain, arousal threshold
- Phase
- Phase 2
- Study type
- Interventional
- Recruitment status
- Recruiting
- Enrolment
- 150 participants (estimated)
- Lead sponsor
- University of California, Los AngelesUniversity, hospital or other
- Collaborators
- National Heart, Lung, and Blood Institute (NHLBI)
- Study start
- 7 Jan 2024 (actual)
- Primary completion
- 31 Aug 2028 (estimated)
- Study completion
- 31 Aug 2028 (estimated)
- First posted
- 20 Jul 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.
This study will examine factors associated with outcomes after soft palate surgery and medications (acetazolamide, eszopiclone) that may treat other potential causes of obstructive sleep apnea (loop gain, arousal threshold).
Detailed description
This is a prospective cohort (observational) study of 150 participants with moderate to severe obstructive sleep apnea (OSA) unable to tolerate positive airway pressure who are undergoing drug-induced sleep endoscopy (DISE), including measurement of upper airway closing pressure (Pclose), and tissue-repositioning soft palate surgery. Before and 6 months after surgery, the investigators will measure OSA severity (apnea-hypopnea index) with sleep studies (polysomnograms). Using a recently-validated polysomnography-based signal processing algorithm, the investigators will systematically assess the underlying mechanisms of OSA (traits) and airflow shape (consistent with palate obstruction). The expected 90 participants without resolution of OSA after surgery (surgery failures) will participate in an experimental randomized crossover study of acetazolamide (1 month) and acetazolamide/eszopiclone combination (1 month). Polysomnograms will be performed with each treatment, with algorithm-based determination of traits.
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Crossover
- Masking
- None (open label)
- Number of arms
- 2
- Model description
- Prospective cohort study will include an anticipated 150 study participants undergoing soft palate surgery. The randomized crossover (interventional) study will include the anticipated 90 who do not achieve successful treatment of their obstructive sleep apnea with surgery.
| Arm | Type | Receives |
|---|---|---|
| Acetazolamide | Experimental | Drug: Acetazolamide 500 MG QHSTreatment with acetazolamide 500 mg nightly for 1 month. |
| Acetazolamide/Eszopiclone | Experimental | Drug: Acetazolamide 500 MG QHS, Drug: Eszopiclone 3 mg QHSTreatment with acetazolamide 500 mg and eszopiclone 3 mg nightly for 1 month. |
Who may qualify
- Ages
- 21 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (18 listed)
- age ≥21 years;
- moderate to severe OSA (obstructive AHI ≥ 15 events/hour);
- central/mixed apnea index <5 events/hour;
- intolerance of positive airway pressure (defined as use < 2 hours/night at least 5 nights/week);
- intolerance or poor candidate for oral appliance;
Key exclusion criteria (9 listed)
- history of allergic reaction to either of the study drugs;
- subjects with prior serious allergic reaction (such as Stevens-Johnson syndrome) to sulfonamides;
- subjects with a history of hypersensitivity to either of the two study drugs;
- subjects who are on high-dose aspirin therapy due to risk of severe metabolic acidosis;
- subjects with severe kidney disease or severe liver disease;
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 |
|---|---|---|
| Acetazolamide 500 MG QHSAcetazolamide | Drug | Acetazolamide, Acetazolamide/Eszopiclone |
| Eszopiclone 3 mg QHSEszopiclone | Drug | Acetazolamide/Eszopiclone |
Primary outcome
Apnea-hypopnea index
Time frame: 6 months
apneas plus hypopneas per hour of sleep
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 1 Jul 2026.
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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.
2 sites in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Phase 2 study testing Acetazolamide 500 MG QHS and Eszopiclone 3 mg QHS in people with Obstructive Sleep Apnea, run by University of California, Los Angeles at 2 sites 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 18 inclusion and 9 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: looking for participants now, as of the sponsor's last update on 1 Jul 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 2 sites 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?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Eric J Kezirian, MD, MPH (32344257904242596559, EKezirian@mednet.ucla.edu), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Apnea-hypopnea index (time frame: 6 months). 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 1 Jul 2026.