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Not yet taking people in AustraliaPhase 2/3

Tirzepatide compared with CPAP for obstructive sleep apnoea in people with overweight

Compares tirzepatide with a CPAP breathing machine in adults with obstructive sleep apnoea.

Key facts

Who runs it
Woolcock Institute of Medical Research
Where
Macquarie Park, AustraliaSee the site
Trial code
Registry title
Tirzepatide Versus Positive Airway Pressure for the Treatment of Obstructive Sleep Apnoea
Status
Not yet recruiting
Phase
Phase 2/3
People taking part
256 people, planned
Started
1 Oct 2026
Expected to end
1 Dec 2028
Type of study
Interventional, 2 groupsOne group gets an existing treatment, for comparison.
Treatments tested
  • Continuous Positive Airway Pressure
  • Tirzepatide
Record updated
2 November 2026

Who can take part

AI summary

From the trial's eligibility criteria. Machine-read from the registry text on this page, so it can be wrong. The registry text below and the trial team decide who can take part.

The trial is looking for adults with moderate to severe obstructive sleep apnoea and overweight or obesity. It compares tirzepatide with CPAP.

Age
18 years or older
Sex
Women and men can join.
Disease stage
Moderate to severe sleep apnoea (AHI 15 or more per hour on a Type 1 or 2 sleep study in the last 12 months, with CPAP advised) and a BMI of 27 kg/m2 or more (25 kg/m2 or more for Asian people).
Earlier treatment
Cannot have used CPAP, a mouth device or positional therapy in the last 3 months. Cannot have had a GLP-1 receptor agonist, a glucose-lowering medicine or a weight-loss medicine within 90 days before screening or baseline.
Biomarker or test result
HbA1c must be below 48 mmol/mol (6.5%) at screening.

Main reasons for not taking part

  • Type 1 or type 2 diabetes
  • Breathing failure, obesity hypoventilation syndrome or moderate to severe COPD
  • Central sleep apnoea or Cheyne-Stokes breathing in more than 50% of breathing events
  • Pregnancy, breastfeeding or planning a pregnancy during the trial
  • Any reason that rules out tirzepatide or CPAP, or past surgery for sleep apnoea

The registry criteria, word for word

Show all 21 criteriaShow less

Who can take part

  • Females and Males aged ≥ 18 years at the time of signing informed consent
  • Moderate-severe OSA defined as an AHI ≥ 15/hr determined from a Type 1 or 2 sleep study conducted within the previous 12 months with a clinician recommendation for CPAP therapy
  • Moderate overweight or obesity defined as BMI ≥ 27 kg/m2. (Adjusted to BMI ≥ 25 kg/m2 for Asian populations as per WHO guidelines (WHO Expert Consultation (2004))
  • No contraindication to tirzepatide use as per Australian Product Information
  • Home internet access to enable cloud storage of SleepTracker-AI in-home BDI
  • Fluent English literacy and able to provide informed consent

Who cannot take part

  • Driver occupation with excessive sleepiness (Epworth Sleepiness Scale >=16) or sleepiness-related motor vehicle accident or near accident within 12 months prior to enrolment
  • Current or prior (≤3 months) OSA treatment with mechanical therapy (CPAP, MAS, Positional)
  • Relative or absolute contraindication to CPAP including chronic cranial injury; recurrent pneumothorax; indication for oral-pharyngeal surgery, significant craniofacial abnormalities that may affect breathing, or are unwilling to use CPAP
  • Any previous or planned surgery for OSA or major ear, nose or throat surgery, including tonsillectomy and adenoidectomy that still may affect breathing (NB: Inclusion of a participant with more minor ear, nose or throat surgery (for example, deviated septum) will be at the investigator's discretion); Glycaemia related criteria:
  • Treatment with a GLP-1 receptor agonist within 90 days before screening; Obesity related criteria:
  • A self-reported change in body weight >5 kg or >5% within 90 days before baseline
  • Treatment with medication for the indication of obesity within 90 days before baseline and/or currently enrolled in a weight loss program; Other criteria:
  • Respiratory failure including obesity hypoventilation syndrome (OHS) or daytime hypercapnia or moderate-severe chronic obstructive pulmonary disease (COPD) with FEV1/FVC ratio<0.7 and FEV1<80% predicted (GOLD criteria)
  • Type 1 or type 2 diabetes mellitus
  • HbA1c ≥ 48 mmol/mol (6.5%) at screening
  • Treatment with glucose-lowering agent(s) within 90 days before screening
  • OSA or other respiratory related criteria:
  • >50% respiratory events with Cheyne-Stokes Respiration (CSR) or Central Sleep Apnoea (CSA)
  • Pregnancy/breast feeding or planning a pregnancy during the trial period
  • Relative or absolute contraindication to tirzepatide including needle phobia

Where in Australia

  • Woolcock Institute of Medical ResearchMacquarie Park, AustraliaContact: Greg Kaplan, PhDNo longer taking part

About the trial

What the trial wants to find out

When used, continuous positive airway pressure (CPAP) is an effective treatment for obstructive sleep apnea (OSA), a condition that is mainly caused by overweight and obesity. However, CPAP is plagued by poor adherence and high rates of discontinued use leaving most patients undertreated and at risk of serious health complications. This study aims to test whether new effective weight loss pharmacotherapy is superior to CPAP for alleviating OSA and improving health outcomes.

The 2 groups in the trial

  • Continuous Positive Airway Pressure (CPAP)Existing treatment, for comparison

    Treatment: Continuous Positive Airway Pressure

  • TirzepatideTreatment being tested

Questions to ask the study team

  1. How often do I need to come in, and for how long each time?
  2. Are travel costs paid?
  3. Can I keep my own doctor?
  4. What happens if I want to stop?

Contact the study team: see the registry record → Contacts and Locations

Print a page for my doctor

Data and sources

Registry record
Listed on ClinicalTrials.gov.
Official title
Tirzepatide Versus Positive Airway Pressure for the Treatment of Obstructive Sleep Apnoea: A Randomised Comparative Effectiveness Trial
Plain-language title
Tirzepatide compared with CPAP for obstructive sleep apnoea in people with overweightGenerated from the registry record. The registry title is the official one.
AI summary
From the trial's eligibility criteria. Read by machine on 12 November 2026.
Record updated
2 November 2026