Eli Lilly's tirzepatide scores again, this time in 2 sleep apnea trials

In addition to their acclaimed efficacy against diabetes and obesity, GLP-1 drugs are gaining traction for their potential to treat a variety of other common disorders.

Add another to the list as two trials have shown that Eli Lilly’s weight loss product Zepbound (tirzepatide) can help patients overcome obstructive sleep apnea (OSA), a condition that disrupts breathing during sleep and has been diagnosed in 20 million in the United States.

The phase 3 studies, both a year long, demonstrated that patients taking tirzepatide had about 30 fewer sleep apnea events per hour than those on placebo. Both trials—one for patients using continuous positive airway pressure (CPAP) and the other without—met all primary and secondary endpoints.

All patients in the studies were obese and had moderate-to-severe OSA. Those who received a 10 mg or 15 mg injection of tirzepatide saw a median reduction in their apnea-hypopnea index (API) of up to 63%, the company said. The index measures the number of times a person’s breathing shows a restricted or complete block of airflow per hour and is the primary tool in evaluating the severity of OSA and the effectiveness of treatments.

In the SURMOUNT-OSA Study 1, which evaluated the effectiveness of tirzepatide among those not using CPAP machines, the Lilly drug was associated with a mean reduction from baseline of 27.4 events per hour, compared to 4.8 for placebo. Investigators also recorded an 18.1% mean weight reduction for tirzepatide versus 1.3% for those on placebo.

In the SURMOUNT-OSA Study 2 for patients on CPAP, there was a mean reduction of 30.4 events per hour compared to 6.0 for placebo. Additionally, the mean weight loss was 20.1% for tirzepatide versus 2.3% for those on placebo.

OSA is characterized by collapses of the upper airway during sleep, which can lead to a decrease in oxygen saturation and waking from sleep. By forcing air into the system, CPAP machines can keep the airway open. OSA can have serious complications, including high blood pressure, heart disease, stroke, heart failure, atrial fibrillation and type 2 diabetes.

Lilly’s chief of product development, Jeff Emmick, M.D., Ph.D., said in a release that 85% of those with sleep apnea are “undiagnosed and untreated.”

“Addressing this unmet need head-on is critical, and while there are pharmaceutical treatments for the excessive sleepiness associated with OSA, tirzepatide has the potential to be the first pharmaceutical treatment for the underlying disease,” Emmick added.

Lilly released only partial results from the studies and said it will present more data at the American Diabetes Association’s 84th Scientific Sessions on June 21. The company, which has already received FDA fast-track designation for tirzepatide to treat OSA, will submit the results to regulatory authorities beginning in the middle of this year, it added.

Analysts at Leerink Partners noted that there are no drugs approved to treat OSA, with standard of care including central nervous system stimulants and dopamine/norepinephrine reuptake inhibitors.

"We assume that these data could result in priority review and approval by early 2025," the analysts wrote. "The addition of OSA to the label could provide a meaningful entry-point for access and we note that 70% of OSA patients are obese."

Zepbound, which was approved in November, is Lilly’s obesity therapy which contains the same compound as the company’s type 2 diabetes drug Mounjaro, which also has been commonly prescribed off label as a weight-loss treatment.

Novo Nordisk’s comparable drugs Wegovy, for weight loss, and Ozempic, for type 2 diabetes, are GLP-1 (glucagon-like peptide-1) treatments while Lilly’s drugs combine the dual action of GLP-1 and GIP (glucose-dependent insulinotropic polypeptide).

Last month, the FDA expanded Wegovy’s label to reduce the risk of cardiovascular risk, heart attack and stroke in those who are overweight.

Two months ago, Lilly presented data from a mid-stage trial that demonstrated tirzepatide's potential to treat the fatty liver disease metabolic dysfunction-associated steatohepatitis (MASH).