Lilly's Zepbound eyes FDA approval for sleep apnea amid competition with Novo's Wegovy

Eli Lilly has taken significant strides towards expanding the usage of its weight-loss medication, Zepbound, also known as tirzepatide. The company recently revealed promising outcomes from its phase 3 SURMOUNT-OSA study, which evaluated Zepbound's effectiveness in treating obese patients with obstructive sleep apnea (OSA). The detailed findings were shared in The New England Journal of Medicine and presented at the American Diabetes Association’s 84th Scientific Sessions in Orlando, Florida.

Zepbound had previously received approval for obesity treatment in November and is also marketed as Mounjaro for type 2 diabetes at lower doses. In some countries outside the U.S., it is known as Mounjaro for both weight loss and diabetes treatments. Encouraged by these positive trial results, Lilly has submitted an application for Zepbound to the U.S. Food and Drug Administration (FDA) for its use in sleep apnea. The company anticipates a regulatory decision by the end of the year, supported by the drug's fast-track designation for moderate-to-severe OSA in obese patients.

The trial results are compelling. Zepbound demonstrated a mean reduction of up to 62.8% on the apnea-hypopnea index (AHI), which measures the severity of OSA by tracking sleep-related breathing issues per hour of sleep. This reduction translated to approximately 30 fewer events of blocked or restricted airflow per hour compared to a placebo. Additionally, 43% of patients not using positive airway pressure (PAP) therapy and 51.5% of those using PAP machines who received the highest dose of Zepbound met criteria for disease resolution. Disease resolution was defined as an AHI of fewer than five events per hour or an AHI of 5 to 14 events per hour with an Epworth Sleepiness Scale (ESS) score of up to 10, a questionnaire assessing excessive daytime sleepiness.

In the United States, approximately 80 million people struggle with obstructive sleep apnea, a condition lacking dedicated pharmaceutical treatments to address its underlying causes. Dr. Jeff Emmick, Lilly’s senior vice president of product development, emphasized the significance of these findings, noting that OSA can exacerbate serious cardiometabolic complications, including hypertension, coronary heart disease, stroke, heart failure, atrial fibrillation, and type 2 diabetes.

Moreover, patients treated with Zepbound in both studies experienced significant improvements across various secondary endpoints, such as systolic blood pressure, hypoxic burden, and high-sensitivity C-reactive protein (hsCRP), an inflammation marker, compared to a placebo.

This milestone for Zepbound is part of a broader success story for tirzepatide. Earlier this month, three doses of the drug helped more than half of metabolic dysfunction-associated steatohepatitis (MASH) patients reduce their fibrosis by at least one stage without disease worsening. Beyond sleep apnea and fatty liver disease, Lilly is also investigating tirzepatide's potential in treating heart failure with preserved ejection fraction.

Despite these advancements, Lilly is still catching up to Novo Nordisk in the diabetes and obesity markets. In March, Novo’s Wegovy became the first weight loss treatment to receive FDA approval for reducing the risk of cardiovascular death, heart attack, and stroke in adults with cardiovascular disease who are obese or overweight.

In terms of financial performance, Mounjaro generated $5.16 billion for Lilly in the treatment of type 2 diabetes throughout 2023, while Zepbound contributed $175.8 million. Meanwhile, Novo’s Ozempic brought in approximately $13.8 billion, and Wegovy added around $4.5 billion to Novo Nordisk’s 2023 sales.

Lilly's recent progress with Zepbound highlights its potential to address a significant unmet medical need in patients with obstructive sleep apnea, marking another step forward in the competitive landscape of weight-loss and diabetes treatments.