Eli Lilly reports positive sleep apnea results for obesity pill Foundayo

Eli Lilly announced on Monday that its daily obesity medication, Foundayo, demonstrated a significant reduction in the severity of obstructive sleep apnea during a late-stage clinical trial. The drugmaker intends to submit a request to the U.S. Food and Drug Administration for approval of the pill for moderate-to-severe obstructive sleep apnea in adults who are overweight or have obesity by the end of the year.

Obstructive sleep apnea is a common sleep-related breathing disorder characterized by interrupted breathing during sleep caused by narrowed or blocked airways. These interruptions can lead to drops in oxygen levels and increases in blood pressure, which are linked to serious health complications such as hypertension, heart failure, and stroke. According to the National Council on Aging, the condition affects nearly 1 billion adults globally, including 80 million people aged 20 and older in the United States. Lilly noted that a majority of those affected have never received a diagnosis.

The new trial results position Foundayo, which launched in the U.S. market in April, as one of several treatments from the GLP-1 class showing potential for addressing this condition. Previously, Eli Lilly’s weight loss injection Zepbound became the first medication to receive U.S. approval for obstructive sleep apnea in December 2024. Outside of that specific injection, patients have had limited treatment options, with many relying on positive airway pressure devices to maintain normal breathing patterns.

Dr. Thomas Seck, senior vice president of product development for Lilly Cardiometabolic Health, stated that Foundayo is already making a difference for individuals living with obesity. He added that with plans to submit the trial results to the FDA by year's end, the company sees an opportunity to assist those managing obstructive sleep apnea.

The clinical data came from two independent studies. The first study included 363 patients who were unable or unwilling to use positive airway pressure therapy. The second study comprised 349 individuals who had been using positive airway pressure therapy for at least three months prior to screening and continued that treatment throughout the trial. In both groups, participants started with a low dose of Foundayo and gradually increased it at four-week intervals to reach various maximum dosages.

Researchers focused on the apnea-hypopnea index, a metric that records the number of times per hour a person's breathing is restricted or completely blocked. This index is standard for evaluating the severity of the condition and the effectiveness of treatments. For patients not using positive airway pressure therapy, those taking Foundayo experienced an average reduction of 21.1 events per hour at 52 weeks. In contrast, the placebo group saw an average reduction of only 4.8 events per hour.

The medication also met its secondary goal in the non-device group, resulting in an overall reduction of 43.8% in the apnea-hypopnea index, compared to a 6.3% decrease in the placebo group. Lilly reported that 31.5% of participants in the Foundayo group met the criteria for remission or improvement to mild obstructive sleep apnea.

For patients using both Foundayo and positive airway pressure therapy, the average reduction in events was 18.3 per hour at 52 weeks, compared to 5.5 per hour for the placebo. The overall reduction in the index was approximately 27.5% for the combination group, while the placebo group saw a 3% decrease. Additionally, 19.6% of participants in this group met the criteria for remission or mild disease.

The trial also measured the sleep apnea-specific hypoxic burden, which tracks the depth and duration of oxygen level drops during sleep. This metric decreased by 55.9% in patients not using positive airway pressure therapy and by 45.8% in those who were. Eli Lilly noted that the pill also contributed to weight loss of roughly 11% across groups at the 52-week mark and helped lower a marker of inflammation.

Safety data from the trial were consistent with previous studies of the medication. Approximately 12% of patients on Foundayo without positive airway pressure therapy discontinued the drug due to side effects, compared to 3.8% in the placebo group. Among those using both the pill and the device, 6.8% stopped due to side effects, compared to 0.6% in the placebo group. The most common adverse effects were gastrointestinal in nature, including nausea, diarrhea, constipation, and vomiting, and were generally mild to moderate, a pattern consistent with other GLP-1 medications.