The US Food and Drug Administration (FDA) approved Eli Lilly’s Zepbound (tirzepatide) injection for chronic weight management in adults with obesity or those who are overweight and also have at least one weight-related medical condition, such as obstructive sleep apnea (OSA).

The approval was based on results from the phase 3 SURMOUNT-1 and SURMOUNT-2 trials. In SURMOUNT-1, a study of 2,539 adults with obesity or excess weight and weight-related medical problems not including diabetes, people taking Zepbound as an adjunct to diet and exercise experienced substantial weight loss compared with placebo at 72 weeks.

At the highest dose (15 mg), people taking Zepbound lost on average 48 pounds, while at the lowest dose (5 mg), people lost on average 34 pounds. Additionally, 1 in 3 patients taking Zepbound at the highest dose lost over 58 pounds (25% of body weight), compared to 1.5% on placebo, according to data not controlled for type 1 error. The average starting weight was 231 pounds.

A placebo-controlled, 52-week phase 3 clinical trial, SURMOUNT-OSA, currently is underway to investigate the efficacy and safety of tirzepatide for the treatment of moderate to severe OSA in participants with obesity. Approximately 412 participants will be randomly assigned to placebo or tirzepatide to explore whether tirzepatide provides clinically meaningful improvement in obesity-related OSA by targeting an underlying etiology.

Zepbound activates receptors of hormones secreted from the intestine (glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic polypeptide (GIP) to reduce appetite and food intake. “Given that weight loss is recommended for the majority of patients with OSA, GLP-1 agonists have the potential to play a major role in OSA treatment,” according to researchers of a recent study investigating the role of GLP-1 agonists in improving OSA. 

Zepbound is administered by injection under the skin once weekly, and the dosage must be increased over four to 20 weeks to achieve the target dosages of 5 milligrams, 10 milligrams, or 15 milligrams once weekly. The maximum dosage of Zepbound is 15 milligrams once weekly.

“Obesity and overweight are serious conditions that can be associated with some of the leading causes of death such as heart disease, stroke, and diabetes,” says John Sharretts, MD, director of the division of diabetes, lipid disorders, and obesity in the FDA’s Center for Drug Evaluation and Research. “In light of increasing rates of both obesity and overweight in the United States, today’s approval addresses an unmet medical need.” 

Approximately 70% of American adults have obesity or excess weight, and many of those overweight have a weight-related condition. Losing 5% to 10% of body weight through diet and exercise has been associated with a reduced risk of cardiovascular disease in adults with obesity or overweight.

Zepbound received Priority Review and Fast Track designations for this indication.

Photo caption: Zepbound injection

Photo credit: Eli Lilly and Company