The Newest Obesity Drug May Also Combat Sleep Apnea

The newest weight loss drug on the market, Zepbound, might also help keep people’s snoring down. On Wednesday, Eli Lilly announced the preliminary results of two Phase III trials testing its drug tirzepatide for people with both obesity and obstructive sleep apnea. Not only did those taking the drug lose much more weight than those on placebo, they also breathed easier at night and experienced substantially fewer episodes of sleep apnea.

Tirzepatide is the latest in a class of drugs known as incretins, which mimic gut and brain hormones important to regulating our hunger and metabolism. The drug is the first approved incretin medication to combine two of these hormones at once, GLP-1 and GIP—a dual-action mechanism that makes for a more potent effect. In clinical trials, people have lost an average 20% or more of their baseline weight, well above the typical success seen with diet and exercise alone. These results have even surpassed the average 15% weight loss seen with Novo Nordisk’s semaglutide (sold under the names Ozempic and Wegovy), the first of these newer incretin drugs to receive regulatory approval.

The potential benefits of these medications are expanding well beyond weight loss, however. Large-scale trials have shown that incretin therapy can reduce the chance of future heart and kidney problems in obese people at higher risk for them, for instance. And early research has suggested that these drugs might even be able to help treat substance use disorder and reduce people’s depression and anxiety symptoms.

Though scientists are still figuring out exactly how incretins affect the body, much of their benefit is likely tied to the weight loss that comes from taking them. While obesity in of itself is not necessarily unhealthy, it can raise the risk of or worsen many chronic conditions, particularly obstructive sleep apnea. So the hope is that tirzepatide and other incretins might be able to help treat both conditions at the same time.

This latest research is an extension of the trials that secured tirzepatide’s FDA approval for obesity last year (sold under the name Zepbound). Eli Lilly ran two Phase III studies of people living with obesity and moderate-to-severe obstructive sleep apnea for 52 weeks each. Both studies were placebo-controlled and randomized, but in one trial, participants were also taking positive airway pressure therapy, a standard treatment for sleep apnea.

Sleep apnea is defined by the body’s inability to breathe during sleep, which causes the brain to wake the person just enough to start breathing again, only for the cycle to restart once the person falls back asleep. The more severe a person’s apnea, the more these episodes of stopped or reduced breathing occur in a night (though not always associated with apnea, snoring is a sign of having narrow airways while sleeping). Sleep apnea doesn’t just mess up people’s bedtime; it’s known to raise the risk of other serious health conditions, such as heart disease.

Across both trials, tirzepatide was clearly superior to placebo at tamping down apnea by the end of the study period. On average, the drug reduced the frequency of these episodes by up to two thirds, with participants experiencing about 30 fewer episodes a hour. Those taking tirzepatide also lost 18% to 20% of their baseline weight on average during the year-long trial, much higher than the 1% to 2% weight loss experienced by those on placebo.

The findings have yet to be published in a peer-reviewed journal, so they merit added caution for now. But if the results are valid, they should pave the way for Eli Lilly to obtain an additional indication for tirzepatide as a treatment for both obstructive sleep apnea (OSA) and obesity. The company plans to submit its data for approval to the FDA and other regulators by mid-year.

“OSA impacts 80 million adults in the U.S., with more than 20 million living with moderate-to-severe OSA. However, 85% of OSA cases go undiagnosed and therefore untreated,” said Jeff Emmick, Eli Lilly senior vice president of product development, in a statement. “Addressing this unmet need head-on is critical, and while there are pharmaceutical treatments for the excessive sleepiness associated with OSA, tirzepatide has the potential to be the first pharmaceutical treatment for the underlying disease.”