April 17, 2024 – Preliminary clinical trial results showed the obesity drug tirzepatide was highly effective at treating obstructive sleep apnea, according to information sent to investors of the pharmaceutical company Eli Lilly.
Indiana-based Eli Lilly sells tirzepatide under the brand name Zepbound, which was approved by the FDA in November to treat overweight and obesity. Tirzepatide is also marketed under the name Mounjaro to treat diabetes, and it's among the same class of drugs as other well-known weight loss and diabetes drugs like Ozempic and Wegovy.
Sleep apnea is a disorder where regular breathing is interrupted or obstructed during sleep, and it's linked to serious health problems affecting the heart, kidneys, and metabolic system. Many people with sleep apnea use a device called a continuous positive airway pressure (CPAP) machine while they sleep to treat the condition.
The newly announced results came from a pair of studies that followed people with moderate to severe obstructive sleep apnea who also had obesity. People in the study took tirzepatide, which is given by injection, for one year. One study evaluated people who were using a sleep apnea device called positive airway pressure during sleep, and another study included people who didn’t use the device. People in both studies taking tirzepatide had significant reductions in sleep events and also lost about 20% of body weight. About 70% of people in the studies were men.
The findings have not yet been published in a peer-reviewed medical journal, and the preliminary results were announced by Eli Lilly because of reporting requirements related to information that could affect stock prices. The company indicated that detailed results will be presented at a conference of the American Diabetes Association in June and will be submitted to a peer-reviewed journal for consideration of publication. The company also plans to submit the information to the FDA for approval consideration mid-year, the investor news release stated.
People in the study taking tirzepatide on average experienced 63% fewer instances of reduced oxygen due to breathing changes, or events when breathing entirely stopped, Eli Lilly reported. The reduction was the equivalent of 30 fewer events per hour. The severity of sleep apnea is measured by the number of events per hour, often referred to as the Apnea Hypopnea Index:
- 30 or more hourly events is severe
- 15 to 29 per hour is moderate
- 5 to 14 per hour is mild
- Less than 5 events per hour is minimal
A sleep expert from Washington University in St. Louis told The New York Times that the initial findings were extremely positive and noted that tirzepatide works to treat the underlying cause of sleep apnea, rather than current treatments that just address symptoms.
Tirzepatide “is a great alternative for people who are obese and can’t use CPAP or are on CPAP and want to improve the effect,” Eric Landsness, MD, PhD, told the Times.
Eli Lilly indicated that the most commonly reported adverse events in the studies were diarrhea, nausea, vomiting, and constipation.
An estimated 39 million people have obstructive sleep apnea and about 33 million people use CPAP machines, according to The National Council on Aging. The condition has been increasingly diagnosed in recent years and becomes more likely to affect people as they get older.