Tirzepatide (Mounjaro) Wins FDA Approval for Type 2 Diabetes

The US Food and Drug Administration (FDA) has granted approval to tirzepatide (Mounjaro) as an adjunct therapy to diet and exercise for improving glycemic control in adults with type 2 diabetes, according to a release from the FDA.

Announced on May 13, approval of the first-in-class, once-weekly dual GLP-1/GIP agonist, which is expected to be available in 2.5 mg, 5 mg, 7.5 mg, 10 mg, 12.5 mg, and 15 mg doses, is based on data from the SURPASS program.

“Given the challenges many patients experience in achieving their target blood sugar goals, today’s approval of Mounjaro is an important advance in the treatment of type 2 diabetes,” said Patrick Archdeacon, MD, associate director of the Division of Diabetes, Lipid Disorders, and Obesity in the FDA’s Center for Drug Evaluation and Research, in the FDA’s announcement.

In the SURPASS program, tirzepatide’s ability to improve glycemic control as a stand-alone agent or adjunct therapyin 5 trials comparing the agent against placebo therapy and other diabetes medications, including semaglutide and 2 long-acting insulin analogs.

In these trials, patients receiving 15 mg tirzepatide experienced a mean HbA1c reduction that was 1.6% greater than those observed with placebo when used as a stand-alone therapy and 1.5% greater than placebo therapy when used in combination with a long-acting insulin. In the trials comparing tirzepatide 15 mg against other diabetes medications, results suggested those receiving tirzepatide had an HbA1c reduction 0.5% greater than semaglutide, 0.9% more than insulin degludec, and 1.0% more than insulin glargine.

In their release, the FDA also touched upon tirzepatide’s effects on obesity and body weight. In the SURPASS program, those randomized to tirzepatide 15 mg had a mean weight loss Han was 15 pounds greater than that observed with placebo when neither were used with insulin and 23 pounds more than placebo when both were used with insulin. In trials comparing tirzepatide to other agents, use of tirzepatide was associated with weight loss that was 12 pounds greater than was observed semaglutide, 29 pounds greater than insulin degludec, and 27 greater than insulin glargine.

"Mounjaro delivered superior and consistent A1C reductions against all of the comparators throughout the SURPASS program, which was designed to assess Mounjaro's efficacy and safety in a broad range of adults with type 2 diabetes who could be treated in clinical practice. The approval of Mounjaro is an exciting step forward for people living with type 2 diabetes given the results seen in these clinical trials," said Juan Pablo Frías, MD, medical director of the National Research Institute and Investigator in the SURPASS program, in a statement from Eli Lilly and Company.

In their release, the FDA noted commonly reported adverse events with tirzepatide included nausea, vomiting, diarrhea, decreased appetite, constipation, upper abdominal discomfort, and abdominal pain. The FDA also noted tirzepatide caused thyroid C-cell tumors in rates but it is not known whether it causes such tumors in humans and should not be used in those with a personal or family history of medullary thyroid cancer or in patients with Multiple Endocrine Neoplasia syndrome type 2. Additionally, the agent has not been studied in patients with a history of pancreas inflammation and is not indicated for use in patients with type 1 diabetes.