“Semaglutide vs Tirzepatide for Weight Loss in Adults With Overweight or Obesity”, 2024-07-08 (; similar):
Question: How does weight loss differ between patients receiving tirzepatide compared with semaglutide among a clinical population of adults with overweight or obesity?
Findings: In this cohort study of 18,386 propensity-score matched patients initiating tirzepatide or semaglutide labeled for type 2 diabetes, discontinuation was common; most achieved weight loss of 5% or greater within 1 year of treatment.
Meaning: Although most adults with overweight or obesity experienced 5% or greater weight loss with treatment, the benefit was greater with tirzepatide.
Importance: Although tirzepatide and semaglutide were shown to reduce weight in randomized clinical trials, data from head-to-head comparisons in populations with overweight or obesity are not yet available.
Objective: To compare on-treatment weight loss and rates of gastrointestinal adverse events (AEs) among adults with overweight or obesity receiving tirzepatide or semaglutide labeled for type 2 diabetes (T2D) in a clinical setting.
Design, Setting, & Participants: In this cohort study, adults with overweight or obesity receiving semaglutide or tirzepatide between May 2022 and September 2023 were identified using electronic health record (EHR) data linked to dispensing information from a collective of US health care systems. On-treatment weight outcomes through November 3, 2023, were assessed. Adults with overweight or obesity and regular care in the year before initiation, no prior glucagon-like peptide 1 receptor agonist receptor agonist use, a prescription within 60 days prior to initiation, and an available baseline weight were identified. The analysis was completed on April 3, 2024.
Exposures: Tirzepatide or semaglutide in formulations labeled for T2D, on or off label.
Main Outcomes & Measures: On-treatment weight change in a propensity score-matched population, assessed as hazard of achieving 5% or greater, 10% or greater, and 15% or greater weight loss, and percentage change in weight at 3, 6, and 12 months. Hazards of gastrointestinal AEs were compared.
Results: Among 41,222 adults meeting the study criteria (semaglutide, 32,029; tirzepatide, 9,193), 18,386 remained after propensity score matching. The mean (SD) age was 52.0 (12.9) years, 12,970 were female (70.5%), 14,182 were white (77.1%), 2,171 Black (11.8%), 354 Asian (1.9%), 1,679 were of other or unknown race, and 9,563 (52.0%) had T2D. The mean (SD) baseline weight was 110 (25.8) kg.
Follow-up was ended by discontinuation for 5,140 patients (55.9%) receiving tirzepatide and 4,823 (52.5%) receiving semaglutide…Rates of gastrointestinal AEs were similar between groups.
Patients receiving tirzepatide were statistically-significantly more likely to achieve weight loss (≥5%; hazard ratio [HR], 1.76, 95% CI, 1.68, 1.84; ≥10%; HR, 2.54; 95% CI, 2.37, 2.73; and ≥15%; HR, 3.24; 95% CI, 2.91, 3.61).
On-treatment changes in weight were larger for patients receiving tirzepatide at 3 months (difference, −2.4%; 95% CI −2.5% to −2.2%), 6 months (difference, −4.3%; 95% CI, −4.7% to −4.0%), and 12 months (difference, −6.9%; 95% CI, −7.9% to −5.8%).
Conclusion & Relevance: In this population of adults with overweight or obesity, use of tirzepatide was associated with statistically-significantly greater weight loss than semaglutide. Future study is needed to understand differences in other important outcomes.