Tirzepatide for Weight Reduction in Chinese Adults With Obesity: The SURMOUNT-CN Randomized Clinical Trial

Abstract

Importance: Obesity has become a global public health concern and China has the largest number of affected people worldwide.

Objective: To assess the efficacy and safety of treatment with tirzepatide for weight reduction in Chinese adults with obesity or overweight and weight-related comorbidities.

Design, setting, and participants: This randomized, double-blind, placebo-controlled, phase 3 clinical trial conducted at 29 centers in China from September 2021 to December 2022 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 1 weight-related comorbidity, excluding diabetes.

Interventions: Participants were randomly assigned (1:1:1) 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.

Main outcomes and measures: Co-primary end points were the percent change in body weight from baseline and weight reduction of at least 5% at week 52. Efficacy and safety analyses were performed on an intention-to-treat population.

Results: Of 210 randomized participants (103 [49.0%] female; mean [SD] age, 36.1 [9.1] years; body weight, 91.8 [16.0] kg; BMI, 32.3 [3.8]), 201 (95.7%) completed the trial. The mean change in body weight at week 52 was -13.6% (95% CI, -15.8% to -11.4%) with tirzepatide 10 mg, -17.5% (95% CI, -19.7% to -15.3%) with tirzepatide 15 mg, and -2.3% with placebo (difference between 10 mg and placebo, -11.3% [95% CI, -14.3% to -8.3%; P < .001]; difference between 15 mg and placebo, -15.1% [95% CI, -18.2% to -12.1%; P < .001]). 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 (P < .001 for comparisons 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%).

Conclusions and relevance: In Chinese adults with obesity or overweight, once-weekly treatment with tirzepatide 10 mg or 15 mg resulted in statistically significant and clinically meaningful weight reduction with an acceptable safety profile.

Trial registration: ClinicalTrials.gov Identifier: NCT05024032.

Figure 1.. Flow of Participants in the SURMOUNT-CN Trial

^aIncludes 1 participant who was not able to commit to the study visit schedule due to time conflicts and failed screening. ^bRandomization was stratified by sex (female, male) according to fixed selection categories and the presence of weight-related comorbidities (yes, no). ^cSee Table 3 for details of the adverse events that led to treatment discontinuation. ^dGuided by the treatment regimen estimand.

Figure 2.. Effect of Tirzepatide vs Placebo on Body Weight and Waist Circumference

Data are observed (as-measured) changes during treatment (time from randomization to last contact with trial site, irrespective of treatment discontinuation) for each participant in the full analysis set. The lines in each box represent the median; small squares, the mean. Box tops and bottoms represent the IQR; whiskers extend to most extreme observed values with 1.5× the IQR of the nearer quartile; and symbols beyond these points are values outside that range. A and C, More negative values indicate greater reductions. Numbers in the key represent the full analysis set. B shows participants at baseline (gray lines) and with measurement at 52 weeks. Overall n’s are the same as in panels A and C.