- Design
- Two phase 3, randomised, double-blind, placebo-controlled trials, 80 weeks
- Population
- 691 adults with moderate-to-severe OSA and BMI ≥27, with or without type 2 diabetes
- Primary outcome
- Change in apnoea-hypopnoea index at 80 weeks (9 and 12 mg)
- Effect
- Difference vs placebo -21.9 to -24.4 (no diabetes) and -14.4 to -15.1 (diabetes) events/hour
Two phase 3 placebo-controlled trials, nested in larger obesity programmes, randomised adults with moderate to severe obstructive sleep apnoea (OSA) and a BMI of 27 or more to weekly retatrutide (4, 9 or 12 mg) or placebo. TRIUMPH-1-OSA (243 people) excluded type 2 diabetes; TRIUMPH-2-OSA (448) included it. Retatrutide acts on GIP, GLP-1 and glucagon receptors. Published in the New England Journal of Medicine on 21 October 2026.
Baseline apnoea-hypopnoea index (AHI) was about 56 to 59 events an hour. At 80 weeks, retatrutide 9 mg and 12 mg reduced the AHI by 22 to 24 events an hour more than placebo in people without diabetes, and by 14 to 15 in those with diabetes. Weight fell 12% to 22%, against about 5% on placebo. Side effects were mainly gastrointestinal.
Most of the benefit is likely to come from weight loss, and many participants were still in the moderate range at the end. Retatrutide is not approved anywhere.
- Retatrutide is investigational; it cannot be prescribed
- Treat substantial weight loss as a reason to recheck OSA severity
- Do not stop CPAP in patients losing weight without a repeat sleep study
- Expect smaller OSA improvements in people with type 2 diabetes
- Ask about snoring and daytime sleepiness in every patient with obesity
Why it matters
Sleep apnoea is becoming a condition treated partly with medicines, not only machines.
Don't overread it
Most participants still had sleep apnoea at 80 weeks; this is not a cure.
The statistics, in plain English
The trials report two estimands: a hybrid one that sets aside people whose treatment failed, and an intention-to-treat one that counts everyone. Both gave similar results, which makes the finding more robust.
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