Abstract Aims This analysis aimed to assess the influence of selected baseline factors on tirzepatide treatment response in Japanese patients with obesity disease. Materials and Methods This was a prespecified subgroup analysis of the SURMOUNT‐J trial. Japanese adults with obesity disease, excluding diabetes, were randomised 1:1:1 to receive once‐weekly subcutaneous tirzepatide 10 mg, tirzepatide 15 mg, or placebo. Key safety and efficacy outcomes at week 72 were analysed by baseline characteristics, including sex, age (<65, ≥65 years), and body mass index (BMI; <35 kg/m 2 , ≥35 kg/m 2 ). Post hoc analyses were conducted to examine cardiometabolic parameters by subgroup. Results Overall, 225 participants were examined (tirzepatide 10 mg: n = 73; tirzepatide 15 mg: n = 77; placebo: n = 75). Weight reduction at week 72 was generally similar across subgroups. Numerically greater reductions in percent body weight at week 72 were observed in females (estimated treatment differences: 10 mg, −17.5%; 15 mg, −24.9%) compared with males (10 mg, −15.1%; 15 mg, −18.1%) and in the BMI <35 kg/m 2 subgroup (10 mg, −18.7%; 15 mg, −21.7%) compared with the BMI ≥35 kg/m 2 subgroup (10 mg, −11.7%; 15 mg, −20.4%) with tirzepatide compared with placebo. Higher proportions of participants achieved ≥5% weight reduction following week 72 of tirzepatide (86%–100%) compared with placebo (18%–30%) across subgroups, and all subgroups showed improvements in cardiometabolic parameters with tirzepatide. Safety profiles did not substantially differ by subgroup. Conclusions These results suggest that tailored interventions such as tirzepatide dosage adjustments may help optimise the treatment management of Japanese patients with obesity disease. Study registration ClinicalTrials.gov , NCT04844918.
Yokote et al. (2025) studied this question.