Eli Lilly and Company announced detailed results from the SURMOUNT-OSA phase 3 clinical trials evaluating tirzepatide injection (10 mg or 15 mg) for the treatment of moderate-to-severe obstructive sleep apnea (OSA) in adults with obesity, with and without positive airway pressure (PAP) therapy. In both studies, tirzepatide achieved all primary and key secondary endpoints for both the efficacyi and treatment-regimenii estimands and demonstrated a mean reduction of up to 62.8% on the apnea-hypopnea index (AHI), or about 30 fewer events restricting or blocking a person's airflow per hour of sleep, compared to placebo. In a key secondary endpoint, the efficacy estimand showed that 43.0% (Study 1) and 51.5% (Study 2) of participants treated with tirzepatide at the highest dose met the criteria for disease resolution.

In this context, "disease resolution" means achieving an AHI of fewer than 5 events per hour, or an AHI of 5-14 events per hour and an Epworth Sleepiness Scale (ESS) score of =10. ESS is a standard questionnaire designed to assess excessive daytime sleepiness.1-4 OSA is a complex disease that can impact the progression of serious cardiometabolic complications, including hypertension, coronary heart disease, stroke, heart failure, atrial fibrillation and type 2 diabetes.5 Participants treated with tirzepatide in both studies experienced significant improvements in all key secondary endpoints including systolic blood pressure, hypoxic burden and high-sensitivity C-reactive protein (hsCRP), an inflammation marker, compared to placebo. The overall safety profile of tirzepatide in SURMOUNT-OSA studies was similar to previously reported SURMOUNT and SURPASS trials.

The most commonly reported adverse events in SURMOUNT-OSA were gastrointestinal related and generally mild to moderate in severity. The most frequent events reported by those on tirzepatide compared with placebo, respectively, were diarrhea (26.3% vs 12.5%), nausea (25.4% vs 10.0%) and vomiting (17.5% vs 4.2%) in SURMOUNT-OSA Study 1, and diarrhea (21.8% vs 8.8%), nausea (21.8% vs 5.3%) and constipation (15.1% vs 4.4%) in SURMOUNT-OSA Study 2. Adverse events led to discontinuation of study treatment in 9 participants taking tirzepatide (5 in Study 1 and 4 in Study 2) and 10 taking placebo (2 in Study 1 and 8 in Study 2). Tirzepatide is the only approved GIP (glucose-dependent insulinotropic polypeptide) and GLP-1 (glucagon-like peptide-1) treatment for chronic weight management, commercialized as Zepbound® in the U.S. and Mounjaro® in some global markets outside the U.S. Lilly submitted tirzepatide for the treatment of moderate-to-severe OSA and obesity to the U.S. Food and Drug Administration (FDA) with regulatory action anticipated as early as the end of this year.

Lilly received FDA Fast Track designation for moderate-to-severe OSA in patients with obesity.