Drugmaker Eli Lilly announced Wednesday that its obesity drug tirzepatide, or Zepbound, provided significant relief to overweight or obese people who had obstructive sleep apnea, or episodes of breathing that stop during sleep.
The results, from a pair of year-long clinical trials, could offer a new treatment option for the roughly 20 million Americans diagnosed with moderate to severe obstructive sleep apnea. Most people with the condition don’t realize they have it, according to the drug’s maker. People with sleep apnea struggle to get enough sleep and are at increased risk for high blood pressure, heart disease, diabetes, stroke and dementia.
The study findings have not been published in a peer-reviewed medical journal. Eli Lilly provided only a summary of its results — companies are required to announce such findings that can affect their share price as soon as they are received. Dr. Daniel M. Skovronsky, Eli Lilly’s chief scientific officer, said the company is still analyzing the data and will provide detailed results at the American Diabetes Association’s 84 Scientific Sessions in June.
But experts not affiliated with Eli Lilly or involved in its studies were encouraged by the summary.
“This is awesome,” said Dr. Henry Clare Yagi, director of the Yale Sleep Medicine Centers in New Haven, Conn.
He added that the most common treatment, a CPAP machine that forces air into the airway, keeping it open during sleep, is effective. About 60 percent of patients who use continuous positive airway pressure continue to use it, he said.
Dr. Eric Landsness, a sleep medicine researcher at Washington University in St. Louis, said Lilly’s results were “phenomenal.”
They suggest, he said, that tirzepatide “is a great alternative for people who are obese and can’t use CPAP or are taking CPAP and want to improve their outcome.”
He added that unlike current treatments that only treat the symptoms of sleep apnea, the stopped breathing, tirzepatide goes after the underlying cause, the blockages in the airway that cause a person to stop breathing.
Tirzepatide, sold under the brand name Zepbound, was approved by the Food and Drug Administration for weight loss in November. The agency previously approved the diabetes drug Mounjaro. Tirzepatide is part of the class of GLP-1 drugs that includes Ozempic and Wegovy, which are sold by Novo Nordisk.
Patients in these Eli Lilly trials were overweight or obese and had moderate to severe obstructive sleep apnea, with moderate defined as stopping breathing at least 15 times an hour during sleep. The trials did not involve people with central sleep apnea, a type that occurs because the brain stops signaling the muscles that control breathing.
One of Lilly’s studies involved about 200 obese people who were unable or unwilling to use a CPAP machine. Half were randomized to tirzepatide, a weekly injection. The others took a placebo.
Those taking tirzepatide had an average of 27.4 fewer apnea events per hour compared with an average reduction of 4.8 events per hour for the placebo.
The other Lilly trial involved about 200 obese people who used a CPAP machine and were encouraged to continue using it in addition to assessments of apnea episodes. Those who received tirzepatide had an average of 30.4 fewer events per hour after one year of using the drug, compared with an average reduction of six events per hour for participants who received a placebo.
In both studies, participants who received tirzepatide lost about 20 percent of their weight. Eli Lilly’s Dr. Skovronsky attributed the results to loss of fat in the tongue and airways.
Many obese people, Dr. Landsness explained, have fat deposits on the tongue and back of the throat. The throat gets bigger with fat that narrows the airway and the tongue grows in all directions, “like blowing up a balloon,” he said. During sleep, the tongue blocks the flow of oxygen, repeatedly waking the person repeatedly.
The researchers hypothesized that weight loss would reduce episodes of obstructive sleep apnea. But before new drugs like tirzepatide, significant and permanent weight loss was nearly impossible for most people with obesity unless they had bariatric surgery.
Marishka Brown, director of the federal National Sleep Disorders Research Center, said it was hard to know how much weight loss would have on people with sleep apnea.
“Sometimes sleep apnea goes away, but not always,” Dr. Brown said.
For this reason, he added, when asked whether weight loss is an effective treatment, “the research community has been a little cautious about saying yes or no.”
Now, with the new results, that test may change, the researchers said.
Of course, everyone in the study was eligible for tirzepatide anyway—it’s approved for people with obesity, meaning people with a body mass index of at least 30, or people with a body mass index of at least 27 and obese medical conditions.
But insurance companies don’t always pay for tirzepatide for weight loss. The drug’s list price is about $1,000 a month, but insurers pay much less. Eli Lilly sells the drug to people without insurance for $550 a month.
Dr. Skovronsky said Eli Lilly planned to apply to the FDA and drug regulatory agencies around the world asking that tirzepatide be approved to reduce sleep apnea in people who are obese or overweight.
“The goal is for insurance to cover it,” said Dr. Skovronsky.