• Posted November 8, 2023

FDA Approves New Diet Drug Zepbound, a Version of the Diabetes Med Mounjaro

A second injectable diabetes drug has been approved for weight loss in overweight and obese adults, the U.S. Food and Drug Administration announced Wednesday.

The weight-loss drug Zepbound contains the same active ingredient, tirzepatide, as the diabetes drug Mounjaro. Both medications are made by Eli Lilly and Co.

"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,"Dr. John Sharretts, director of the Division of Diabetes, Lipid Disorders, and Obesity in the FDA's Center for Drug Evaluation and Research, said in an agency news release. "In light of increasing rates of both obesity and overweight in the United States, today's approval addresses an unmet medical need."

The approval mirrors the FDA's earlier approval of Wegovy to treat obesity. That blockbuster drug contains the same active ingredient as the diabetes drug Ozempic.

About 7 in 10 American adults are overweight or obese, the FDA said, and many of those folks have at least one weight-related health risk, such as high blood pressure, type 2 diabetes or elevated cholesterol levels.

Losing 5% to 10% of body weight has been associated with a reduced risk of heart disease in adults carrying excess weight, the FDA added.

Zepbound works by activating hormone receptors in the body to reduce appetite and food intake, the agency said. The drug is administered by injection once weekly.

The FDA approved the drug based on two 72-week clinical trials involving more than 2,500 patients who received varying doses of Zepbound and nearly 1,000 patients who got weekly placebo injections.

Patients who got Zepbound at all three dose levels experienced a significant drop in weight compared with those in the placebo group. Greater proportions of patients who received Zepbound achieved at least a 5% weight reduction compared to those getting a placebo.

One trial involving adults without diabetes found that the highest approved dose of Zepbound helped people lose, on average, 18% of their body weight, compared to those receiving placebo.

The other trial, conducted in adults with type 2 diabetes, helped people lose an average of 12% of their body weight compared to those on placebo.

Diana Thiara, medical director of the University of California, San Francisco's Weight Management Program, said Zepbound's effects come close to matching those seen with weight-loss surgeries.

"The high rates of weight loss are really powerful,"Thiara told the Washington Post.

Still, she noted that Zepbound should not be used for short-term weight loss to the exclusion of healthy eating.

"It should be used to calm down that hunger noise, and to focus on nutrition and lifestyle things like exercise,"Thiara explained.

Zepbound's side effects can include nausea, diarrhea, vomiting, constipation, stomach pain, fatigue, allergic reactions, burping, hair loss and acid reflux.

Regulators are also keeping an eye on Zepbound's potential links to thyroid cancer.

The drug has been linked to thyroid C-cell tumors in rats, the FDA said, but it's unknown whether it has a similar effect in humans. Zepbound should not be used in patients with a family history of medullary thyroid cancer or in patients with Multiple Endocrine Neoplasia syndrome type 2.

Zepbound's approval was fast-tracked and received priority review by the FDA.

More information

The U.S. Food and Drug Administration has more about Zepbound.

SOURCE: U.S. Food and Drug Administration, news release, Nov. 8, 2023; Washington Post