Tirzepatide Tops Semaglutide for Weight Loss

TOPLINE:

Individuals with overweight or obesity treated with tirzepatide were significantly more likely to achieve at least 5%, 10%, and 15% body weight loss compared with those treated with semaglutide, regardless of diabetes status.

METHODOLOGY:

• The cohort study included adults with overweight or obesity who initiated either semaglutide (Ozempic, Novo Nordisk) or tirzepatide (Mounjaro, Eli Lilly) treatment between May 2022 and September 2023 from US healthcare systems’ electronic health records.
• Propensity score matching resulted in n = 9193 per treatment group, with 52% of each having type 2 diabetes (T2D).
• Mean duration of on-treatment follow-up was 165 days.

TAKEAWAY

• Just over half of each group — 55.9% of tirzepatide and 52.5% of semaglutide — discontinued treatment.
• The proportions achieving at least 5%, 10%, and 15% weight loss within 1 year with tirzepatide vs semaglutide were 81.8% vs 66.5%, 62.1% vs 37.1%, and 42.3% vs 18.1%, respectively.
• Hazard ratios on comparing tirzepatide with semaglutide for at least 5%, 10%, and 15% weight loss, respectively, were 1.76 (95% CI, 1.68-1.84), 2.54 (2.37-2.73), and 3.24 (95% CI, 2.91-3.61).
• After adjusting for residual confounding, the absolute differences in weight loss between tirzepatide and semaglutide at 3, 6, and 12 months of treatment were −2.4% (95% CI, −2.5% to −2.2), −4.3% (−4.7% to −4.0%), and −6.9% (−7.9% to −5.8%), respectively.
• Individuals without T2D had larger weight reductions than those with T2D in both groups, but tirzepatide was still associated with greater weight loss in all analyses.
• There were no significant differences in gastrointestinal adverse events between tirzepatide and semaglutide.

IN PRACTICE:

“To our knowledge, this study represents the first clinical comparative effectiveness study of tirzepatide and semaglutide in adults with overweight or obesity.”

SOURCE:

The study conducted by Patricia J. Rodriguez, PhD, of Truveta Inc., Bellevue, Washington, and colleagues. It was published online on July 8, 2024, in JAMA Internal Medicine.

LIMITATIONS:

The study had certain limitations such as possible unmeasured confounding, reliance on electronic health record reporting, and reliance on brand as dosing proxy. Moreover, health system and payer information was not available. The sample was from just 35 states, and only medications labeled for T2D were included.

DISCLOSURES:

Rodriguez had no disclosures.