SURMOUNT-1 (tirzepatide 5 mg)
Trial question
What is the role of low-dose tirzepatide in people with obesity?
Study design
Multi-center
Double blinded
RCT
Population
Characteristics of study participants
68.0% female
32.0% male
N = 1273
1273 patients (862 female, 411 male).
Inclusion criteria: adults with a BMI > 30 kg/m², or > 27 kg/m² and at least one weight-related complication, excluding diabetes.
Key exclusion criteria: diabetes; a change in body weight > 5 kg within 90 days before screening; previous or planned surgical treatment for obesity; treatment with a medication that promotes weight loss within 90 days before screening.
Interventions
N=630 low-dose of tirzepatide (at a subcutaneous dose of 5 mg once weekly for 72 weeks).
N=643 placebo (matching placebo once weekly).
Primary outcome
Reduction in weight at week 72
15%
3.1%
15.0 %
11.3 %
7.5 %
3.8 %
0.0 %
Low-dose of
tirzepatide
Placebo
Significant
increase ▲
NNT = 8
Significantly greater reduction in weight at week 72 (15% vs. 3.1%; AD 11.9%, 95% CI 10.4 to 13.4).
Secondary outcomes
Significant increase in the percentage of patients achieving a weight reduction of ≥ 5% at week 72 (85.1% vs. 34.5%; AD 50.6%, 95% CI 20.58 to 80.62).
Significant increase in the percentage of patients achieving a weight reduction of ≥ 10% at week 72 (68.5% vs. 18.8%; AD 49.7%, 95% CI 20.21 to 79.19).
Significantly greater reduction in waist circumference (14 cm vs. 4 cm; AD 10.1 cm, 95% CI 4.11 to 16.09).
Safety outcomes
No significant difference in serious adverse events.
Conclusion
In adults with a BMI > 30 kg/m², or > 27 kg/m² and at least one weight-related complication, excluding diabetes, low-dose of tirzepatide was superior to placebo with respect to reduction in weight at week 72.
Reference
Ania M Jastreboff, Louis J Aronne, Nadia N Ahmad et al. Tirzepatide Once Weekly for the Treatment of Obesity. N Engl J Med. 2022 Jul 21;387(3):205-216.
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