SURMOUNT-2: Tirzepatide Treatment Leads to Average 15% Weight Loss in Adults with T2D, Obesity

Among adults with type 2 diabetes (T2D) and obesity, treatment with tirzepatide was associated with an average weight loss of 15.7% over 72 weeks of treatment, according to the highly anticipated findings from SURMOUNT-2 presented today at the 83rd Scientific Sessions of the American Diabetes Association® (ADA) in San Diego, CA and simultaneously published in The Lancet.

“Tirzepatide reduces weight in patients who have both obesity and type 2 diabetes to an extent we haven’t seen before, greater than any other clinical trials and other weight loss medications,” said principal investigator W TImothy Garvey, MD, professor of nutrition sciences at the at the University of Alabama at Birmingham and Director of the UAB Diabetes Research Center.

Approximately 90% of Americans with diabetes have overweight or obesity, known risk factors for T2D. SURMOUNT-2, a randomized placebo-controlled phase 3 clinical trial was designed to evaluate how tirzepatide, a dual GIP (glucose-dependent insulinotropic polypeptide) and GLP-1 (glucagon-like peptide-1) receptor agonist, affects body weight in overweight individuals with type 2 diabetes. Tirzepatide received approval from the US Food and Drug Administration in May 2023 as an adjunct to diet and exercise to improve glycemic control in persons with T2D.

SURMOUNT-2 study investigators randomly assigned 938 participants who had type 2 diabetes and who had overweight or obesity in a 1:1:1 ratio to receive tirzepatide 10 mg, tirzepatide 15 mg, or placebo. The coprimary endpoints were mean percent change from baseline in body weight and the percentage of participants who achieve a reduction in body weight of at least 5%, both outcomes evaluated through 72 weeks.

FINDINGS

Investigators reported that participants in the groups treated with tirzepatide 10 and 15 mg lost an average of 15% of starting body weight after 72 weeks of treatment. Overall mean weight loss among tirzepatide-treated patients was 14.8 kg or 33 pounds. Mean baseline HbA1c of 8% was reduced to 5.9% at week 72. Moreover, the researchers found that half (49%) of SURMOUNT-2 participants who received tirzepatide reach a normal HbA1c of less than 5.7% without no reports of severe hypoglycemia.

“With a new drug like tirzepatide, it becomes clear we need a weight-centric approach to treating type 2 diabetes when obesity is also present, two conditions that are interwoven for so many Americans,” said W Timothy Garvey, MD, professor of medicine in the Department of Nutrition Sciences at the University of Alabama at Birmingham (UAB), and director of the UAB Diabetes Research Center. “We are encouraged by these weight loss and glycemic control results, especially as weight loss interventions are typically less effective in patients [with] diabetes.”

“With a new drug like tirzepatide, it becomes clear we need a weight-centric approach to treating type 2 diabetes when obesity is also present, two conditions that are interwoven for so many Americans.”

The SURMOUNT-2 study authors support aggressive treatment of obesity, a chronic, relapsing disease, and believe future treatment strategies should target reduction of obesity-related complications, including prevention and management of T2D. Future research, they emphasize, should focus on evaluating potential cardioprotective benefits with tirzepatide treatment including whether the dual incretin agonist may also reduce major adverse cardiovascular events.

Findings from SURMOUNT-1, the first investigational phase 3 trial evaluating the safety and efficacy of tirzepatide for the treatment of obesity, were announced at last year’s 82nd Scientific Sessions of the ADA, and simultaneously published in the New England Journal of Medicine.

Reference: SURMOUNT-2 study finds individuals with type 2 diabetes and obesity lost an average of 15% of their body weight when taking tirzepatide. News release. American Diabetes Association. June 23, 2023. Accessed June 23, 2023.