The U.S. FDA has approved Eli Lilly's tirzepatide injection, branded Zepbound, for chronic weight management in adults with obesity or overweight.
Tirzepatide, branded as Mounjaro, was approved by the FDA last May to improve glycemic control in adults with type 2 diabetes. The injectable drug is a glucose-dependent insulinotropic polypeptide (GIP) receptor and glucagon-like peptide-1 (GLP-1) receptor agonist. It is now the first and only obesity treatment to activate both GIP and GLP-1 hormone receptors.
The approval was based on results from the phase 3 SURMOUNT-1 and SURMOUNT-2 trials. In SURMOUNT-1, a study in 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 — compared to 7 pounds on placebo.
The treatment, which Lilly expects to be available in the U.S. by the end of the year, will go head to head against Novo Nordisk's blockbuster, Wegovy, in an surging obesity market now projected to hit $100 billion in sales by 2030. According to Lilly, Zepbound will be sold at a list price of $1,059.87, which is approximately 20% lower than Novo's semaglutide 2.4 mg injection for weight loss.
Analysts say tirzepatide has the potential to usurp Humira to become the best-selling drug of all time. According to UBS analyst Colin Bristow, the drug is expected to generate annual sales of $25 billion — a figure that would exceed the previous record of $20.7 billion set by AbbVie's Humira in 2021.
