Association of baseline characteristics with clinical outcomes of tirzepatide treatment in Japanese patients with obesity disease: A subgroup analysis of the SURMOUNT-J trial.

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, ≥35 kg/m). 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 subgroup (10 mg, -18.7%; 15 mg, -21.7%) compared with the BMI ≥35 kg/m 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.