FDA Approves New Weight Loss Drug

The FDA has approved Eli Lilly’s Zepbound (tirzepatide) to treat adults who are obese as measured by body mass index or those who are overweight and have high blood pressure, diabetes, or high cholesterol. Tirzepatide is already approved with the name Mounjaro to treat adults with type 2 diabetes.

About 70% of American adults have obesity or overweight, and many of those overweight have a weight-related condition. 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.

Zepbound is administered by injection under the skin once weekly. It is expected to be available by the end of the year in six doses at a list price of $1,059.87, which is about 20% lower than semaglutide, Lilly said in a press release. Lilly will also have a savings card program. Those with commercial insurance who have coverage for Zepbound will be eligible to pay as low as $25 for a one-month to three-month prescription. Those with commercial insurance who do not have coverage for Zepbound may be eligible to pay as low as $550 for a one-month prescription of Zepbound, which is about 50% lower than the list price.

This approval sets up a battle of two large manufacturers competing for market dominance in the weight loss category, noted Jeffrey Casberg, vice president of clinical pharmacy at IPD Analytics and a member of the Managed Healthcare Executive editorial advisory board. He suggested that Lilly’s tirzepatide (Mounjaro and Zepbound) could become the largest selling drug of all time, surpassing even Humira.

Zepbound is even more attractive because Wegovy’s cash price is $14,560 per year compared Zepbound at $7,150 per year based on their coupon programs.

“Lilly has priced Zepbound at a very aggressive cash and list price compared with Novo Nordisk’s Wegovy (semaglutide), a 51% and 21% discount, respectively,” he said. “During a recent Lilly earning call, they spoke of improved supply of Mounjaro, the diabetes version of Zepbound. If this is true, combined with Novo’s supply struggles and the lower priced Zepbound, Lilly could be in position to do very well.

The tirzepatide products along with the semaglutide molecules (Ozempic and Wegovy) could be on a path to $100 billion in sales. For perspective, Humira and Enbrel peak combined gross sales were approximately $45 billion.

The approval was based on the phase 3 SURMOUNT-1 and SURMOUNT-2 trials. In SURMOUNT-1, a study in 2,539 adults with patients taking Zepbound experienced substantial weight loss compared with placebo at 72 weeks. At the highest dose, people taking Zepbound lost on average 48 pounds, while at the lowest dose, people lost on average 34 pounds (compared with seven pounds on placebo). Additionally, one in three patients taking Zepbound at the highest dose lost more than 58 pounds (25% of body weight), compared with 1.5% on placebo.

Thomas A. Wadden, Ph.D.

Principal investigator Thomas A. Wadden, Ph.D., said in an interview last month that weight losses of this size will provide much better control of sleep apnea, osteoarthritis, nonalcoholic steatohepatitis (NASH), type 2 diabetes, and other obesity-related complications that are only marginally improved with a traditional 5% to 10% weight loss.

The most common adverse events related to Zepbound were nausea, diarrhea, vomiting, constipation, abdominal pain, dyspepsia, injection-site reactions, fatigue, hypersensitivity reactions, eructation, hair loss and gastroesophageal reflux disease.

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, the FDA said.

While not approved to treat these conditions, in a clinical trial, people who dieted, exercised and took Zepbound for the treatment of obesity or overweight with weight-related medical problems observed changes in cholesterol and reductions in blood pressure and waist size, Lilly said.

“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,” John Sharretts, M.D., director of the Division of Diabetes, Lipid Disorders, and Obesity in the FDA’s Center for Drug Evaluation and Research, said in a press release. “In light of increasing rates of both obesity and overweight in the United States, today’s approval addresses an unmet medical need.”