SURMOUNT-5
Trial question
What is the effect of tirzepatide compared to semaglutide in patients with obesity?
Study design
Multi-center
Open label
RCT
Population
Characteristics of study participants
65.0% female
35.0% male
N = 750
750 patients (485 female, 265 male).
Inclusion criteria: adult patients with obesity without T2DM.
Key exclusion criteria: diabetes; previous or planned surgical treatment for obesity; treatment with a medication for weight reduction or a GLP-1 receptor agonist in the past 90 days; change in body weight of > 5 kg in the past 90 days.
Interventions
N=374 tirzepatide (at a dose of 10 mg or 15 mg SC once weekly for 72 weeks).
N=376 semaglutide (at a dose of 1.7 mg or 2.4 mg SC once weekly for 72 weeks).
Primary outcome
Reduction in weight at week 72
20.2%
13.7%
20.2 %
15.1 %
10.1 %
5.0 %
0.0 %
Tirzepatide
Semaglutide
Significant
increase ▲
NNT = 15
Significantly greater reduction in weight at week 72 (20.2% vs. 13.7%; MD 6.5, 95% CI 4.9 to 8.1).
Secondary outcomes
Significantly greater reduction in waist circumference at week 72 (18.4 cm vs. 13 cm; MD 5.4, 95% CI 3.6 to 7.1).
Significant increase in the percentage of patients achieving a weight reduction of ≥ 10% (81.6% vs. 60.5%; RR 1.3, 95% CI 1.2 to 1.5).
Significant increase in the percentage of patients achieving a weight reduction of ≥ 25% (31.6% vs. 16.1%; RR 2, 95% CI 1.5 to 2.6).
Safety outcomes
No significant difference in adverse and serious adverse events.
Conclusion
In adult patients with obesity without T2DM, tirzepatide was superior to semaglutide with respect to reduction in weight at week 72.
Reference
Louis J Aronne, Deborah Bade Horn, Carel W le Roux et al. Tirzepatide as Compared with Semaglutide for the Treatment of Obesity. N Engl J Med. 2025 May 11. Online ahead of print.
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