Retatrutide reduces sleep apnea severity in clinical trials

Two Phase 3 clinical trials published in the New England Journal of Medicine indicate that the investigational weight-loss medication retatrutide may significantly reduce the severity of obstructive sleep apnea (OSA).

The trials, TRIUMPH-1-OSA and TRIUMPH-2-OSA, involved 691 participants with moderate-to-severe OSA and obesity. Participants received once-weekly injections of retatrutide at doses of 4 mg, 9 mg, or 12 mg. Results showed that retatrutide reduced the apnea-hypopnea index (AHI)—the average number of breathing interruptions per hour—more effectively than a placebo across all tested doses.

In participants without type 2 diabetes, AHI reductions ranged from approximately 23 to 34 events per hour, compared to roughly 10 events per hour in the placebo group. Among those with type 2 diabetes, reductions ranged from 19 to 25 events per hour. At higher doses, between 39% and 52% of participants reached a state of mild or no sleep apnea without excessive daytime sleepiness, compared to 13% in the placebo group.

Alongside respiratory improvements, participants experienced substantial weight loss, ranging from 12% to 22%. Retatrutide, developed by Eli Lilly, remains an investigational drug and is not yet approved for public use.