Breakthrough in Obesity Treatment: Tirzepatide Shows Promise in Chinese Adults - SURMOUNT-CN Trial

The study, published in the Journal of the American Medical Association (JAMA), showed a greater reduction in body weight with tirzepatide (Zepbound) than with placebo among Chinese adults with obesity or overweight. Participants on tirzepatide and lifestyle intervention lost an average of 15.1% more body weight with the highest dose compared with placebo after 52 weeks.

"In the study of 210 adults without diabetes, mean percent change in body weight at week 52 was −13.6% and −17.5% with tirzepatide 10 mg and 15 mg, respectively, compared with −2.3% with placebo; the differences between each tirzepatide group and the placebo group were statistically significant," the researchers reported.

Obesity, a complex condition with multifactorial origins, has reached epidemic proportions globally, posing significant health risks and economic burdens. Traditional approaches to weight management, including diet and exercise interventions, often fall short of achieving sustainable outcomes for many individuals. As such, the quest for effective pharmacological interventions remains a pressing priority.

Tirzepatide, a dual glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide-1 (GLP-1) receptor agonist has garnered attention for its potent effects on glycemic control and weight reduction in individuals with type 2 diabetes mellitus (T2DM). Lin Zhao, Department of Endocrinology and Metabolism, Zhongshan Hospital, Fudan University, Shanghai, China, and colleagues aimed to assess the safety and efficacy of treatment with tirzepatide for weight reduction in Chinese adults with overweight or obesity and weight-related comorbidities.

For this purpose, the researchers conducted a randomized, double-blind, placebo-controlled, phase 3 clinical trial at 29 centers in China from 2021 to 2022. It included Chinese adults (aged ≥18 years) with a body mass index (BMI) greater than or equal to 28 or greater than or equal to 24 and at least one weight-related comorbidity, excluding diabetes.

Participants were randomly assigned in a 1:1:1 ratio to receive once-weekly, subcutaneous 10-mg (n = 70) or 15-mg (n = 71) tirzepatide or placebo (n = 69), plus a lifestyle intervention, for 52 weeks.

Co-primary endpoints included the percent change in body weight from baseline and weight reduction of at least 5% at week 52. Safety and efficacy analyses were performed on an intention-to-treat population.

The following were the key findings of the study:

• Of 210 randomized participants (49.0% female; mean age, 36.1 years; body weight, 91.8 kg; BMI, 32.3), 95.7% completed the trial.
• The mean change in body weight at week 52 was −13.6% with tirzepatide 10 mg, −17.5% with tirzepatide 15 mg, and −2.3% with placebo (difference between 10 mg and placebo, −11.3%; the difference between 15 mg and placebo, −15.1%).
• The percentage of participants achieving body weight reductions of 5% or greater was 87.7% with tirzepatide 10 mg, 85.8% with tirzepatide 15 mg, and 29.3% with placebo.
• The most frequent treatment-emergent adverse events with tirzepatide were gastrointestinal. Most were mild to moderate in severity, with few events leading to treatment discontinuation (<5%).

"In Chinese adults with overweight or obesity, once-weekly treatment with tirzepatide 10 mg or 15 mg led to statistically significant and clinically meaningful weight reduction with an acceptable safety profile," the researchers wrote.

Reference:

Zhao L, Cheng Z, Lu Y, et al. Tirzepatide for Weight Reduction in Chinese Adults With Obesity: The SURMOUNT-CN Randomized Clinical Trial. JAMA. Published online May 31, 2024. doi:10.1001/jama.2024.9217