Foundayo cut sleep apnea events by 21.1 an hour in late-stage trial

By Amara Osei

Eli Lilly said Monday that Foundayo reduced obstructive sleep apnea severity by 21.1 events per hour at 52 weeks in patients not using positive airway pressure, or PAP, therapy, versus 4.8 for placebo. Lilly plans to file by year-end for U.S. approval of the daily pill to treat moderate-to-severe obstructive sleep apnea, or OSA, in adults with obesity or who are overweight.

Lilly rolled out Foundayo in the U.S. in April, the company said. The obesity pill is one of several GLP-1 treatments to show promise in treating OSA, Lilly said.

Zepbound, Lilly’s blockbuster weight-loss injection, became the first medication to win U.S. approval for OSA in December 2024, according to Lilly. Patients have limited treatment options outside that drug, and many use cumbersome PAP machines to provide positive airway pressure during sleep, the company said.

How large is the OSA treatment gap?

OSA is the most common sleep-related breathing disorder, Lilly said. The condition interrupts breathing during sleep because narrowed or blocked airways can trigger oxygen drops and higher blood pressure. Lilly said those effects are associated with serious complications, including hypertension, heart failure and stroke.

Nearly 1 billion adults globally have OSA, including 80 million people ages 20 and over in the U.S., according to the National Council on Aging. Most have never been diagnosed, Lilly said in a release.

Dr. Thomas Seck, senior vice president of product development of Lilly Cardiometabolic Health, said in a Lilly 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.”

How did Lilly structure the two trials?

Lilly tested Foundayo in two independent late-stage studies. The first included 363 patients with obesity who were unable or unwilling to use PAP therapy. The second included 349 people on PAP therapy for at least three months at screening, who continued treatment during the trial.

Patients in both studies started at a low dose and increased it gradually at four-week intervals to different maximum dosages, Lilly said. Researchers examined the apnea-hypopnea index, or AHI, which counts hourly episodes of restricted or completely blocked breathing. Lilly said the index evaluates OSA severity and treatment effectiveness.

What did Foundayo achieve without PAP therapy?

Patients taking Foundayo without PAP averaged 21.1 fewer AHI events per hour at 52 weeks, compared with a 4.8-event average reduction for placebo, Lilly reported. Foundayo also met the trial’s second goal, with overall AHI down 43.8%, compared with a 6.3% decrease for placebo. Lilly said 31.5% met criteria for remission or improvement to mild OSA.

What happened when patients continued PAP?

Patients taking Foundayo with PAP averaged 18.3 fewer AHI events per hour at 52 weeks, compared with a 5.5-event reduction for placebo, Lilly said. Overall AHI declined around 27.5% with Foundayo and PAP, compared with a 3% decrease for placebo. The company said 19.6% of that Foundayo group met criteria for remission or mild OSA.

Foundayo also reduced sleep apnea-specific hypoxic burden, which measures how deeply and for how long oxygen levels fall during sleep, Lilly said. The metric fell 55.9% among patients not using PAP and 45.8% among those using it.

Lilly said patients lost roughly 11% of their weight across both groups at 52 weeks. The company also said Foundayo lowered a marker of inflammation.

What safety tradeoffs emerged?

Lilly said Foundayo’s safety data and patient tolerability were generally consistent with earlier trials of the pill. About 12% of patients taking Foundayo without PAP discontinued because of side effects, versus 3.8% on placebo, the company said.

Among patients taking Foundayo with PAP, 6.8% discontinued because of side effects, compared with 0.6% taking placebo. The most common side effects were gastrointestinal, Lilly said, including nausea, diarrhea, constipation and vomiting. The company said severity was generally mild to moderate and consistent with other GLP-1 medications.

The planned year-end FDA submission is Lilly’s next regulatory step for adding an OSA indication to Foundayo’s U.S. rollout. Approval would make Foundayo another potential treatment alongside Zepbound for a condition affecting nearly 1 billion adults globally, most of whom Lilly says remain undiagnosed.