Eli Lilly's Foundayo pill cuts sleep apnea severity in late-stage trial, company to seek approval

The results, from two studies involving more than 700 patients, make Foundayo one of several GLP-1-based treatments to show promise against sleep apnea, a condition involving interrupted breathing during sleep. The daily pill rolled out in the U.S. in April.

Obstructive sleep apnea (OSA) is the most common sleep-related breathing disorder, affecting nearly 1 billion adults globally including 80 million people in the U.S. aged 20 and over, according to the National Council on Aging. Most cases have never been diagnosed, Lilly said. The condition can cause drops in oxygen and increases in blood pressure linked to serious complications such as hypertension, heart failure and stroke. Treatment options outside Zepbound have been limited, with many patients using cumbersome positive airway pressure (PAP) machines.

Lilly's injectable weight loss drug Zepbound became the first medication to win U.S. approval for OSA in December 2024.

The trial tested Foundayo in two independent studies. The first included 363 patients who were unable or unwilling to use PAP therapy; the second included 349 patients who had been on PAP therapy for at least three months and continued it during the trial. Patients in both groups started at a low dose of Foundayo and increased it gradually at four-week intervals.

Researchers measured the apnea-hypopnea index (AHI), which records how many times per hour breathing shows a restricted or completely blocked airway. Among patients not using PAP, those on Foundayo had an average of 21.1 fewer AHI events per hour after 52 weeks, compared with 4.8 fewer events per hour for the placebo. Foundayo also led to an overall AHI reduction of 43.8% in that group, versus 6.3% for placebo. Lilly said 31.5% of participants in the Foundayo group met criteria for remission or improvement to mild OSA.

In patients who continued using PAP, those on Foundayo had an average of 18.3 fewer AHI events per hour at 52 weeks, compared with 5.5 fewer for placebo. Foundayo produced an overall AHI reduction of about 27.5% in that group, versus 3% for placebo. Lilly said 19.6% of these patients also met criteria for remission or mild OSA.

The pill also reduced the sleep apnea-specific hypoxic burden, a measure of how deeply and for how long oxygen levels fall during sleep, by 55.9% in those not using PAP and 45.8% in those using it. Lilly said the pill helped patients lose roughly 11% of their weight across groups at 52 weeks and helped lower a marker of inflammation.

Dr. Thomas Seck, senior vice president of product development of Lilly Cardiometabolic Health, said in a release: "Foundayo is already making a difference for people living with obesity, and with plans to submit these results to the FDA by the end of the year, we could have the opportunity to help people living with OSA."

Safety data and how well patients tolerated Foundayo were generally consistent with earlier trials. About 12% of patient not using PAP who took Foundayo discontinued the drug due to side effects, compared with 3.8% on placebo. Among those also using PAP, 6.8% on Foundayo discontinued versus 0.6% on placebo. The most common side effects were gastrointestinal, including nausea, diarrhea, constipation and vomiting, and were generally mild to moderate in severity, consistent with other GLP-1 medications.