Efficacy and Safety of Tirzepatide in Japanese Participants With Obesity: A Subpopulation Analysis of the SURMOUNT ‐1 Trial

ABSTRACT Objective This prespecified subpopulation analysis aimed to assess the efficacy and safety of once‐weekly tirzepatide versus placebo alongside lifestyle intervention in Japanese adults with obesity or overweight. Methods Data from 102 Japanese adults in the SURMOUNT‐1 trial with BMI ≥ 30 kg/m 2 or ≥ 27 kg/m 2 and ≥ 1 weight‐related comorbidity were analyzed. Coprimary endpoints were mean percent change in body weight and the proportion of participants who achieved ≥ 5% body weight reduction at week 72. Results Participants in the tirzepatide 5‐, 10‐, and 15‐mg groups had a statistically significantly greater (all p < 0.001) least squares mean (standard error) percent change in body weight compared with those in the placebo group: −12.0% (1.7%), −22.4% (1.7%), −22.1% (1.6%), and −0.3% (1.6%), respectively. Overall, 91.7%, 100%, and 96.6% of participants in the tirzepatide 5‐, 10‐, and 15‐mg groups, respectively, had ≥ 5% weight reduction at week 72, compared with 15.4% in the placebo group. Significant improvements in cardiometabolic measures were also observed with tirzepatide at week 72 compared to placebo. No new safety concerns were identified. Conclusions Once‐weekly treatment with tirzepatide demonstrated significant reductions in body weight and prespecified cardiometabolic measures compared with placebo in Japanese adults with obesity or overweight. Trial Registration ClinicalTrials.gov identifier: NCT04184622 https://clinicaltrials.gov/study/NCT04184622