TOPLINE: 

In real-world settings, tirzepatide leads to substantial weight loss; however, patients who have already lost weight prior to initiation experience smaller additional reductions than those near their maximum total body weight (TBW). Among patients switching from semaglutide, those transitioning due to weight-loss plateau achieve greater additional weight loss than those transitioning due to nonresponse.

METHODOLOGY: 

• In clinical practice, patients vary in baseline weight and often switch obesity medications due to tolerability, nonresponse, or insurance issues. Identifying response predictors may help guide patient expectations and treatment decisions.
• Researchers conducted a retrospective cohort study analyzing 6-month weight-loss outcomes in adults treated with tirzepatide at an urban academic weight management center between May 2022 and January 2023.
• Patients were classified as weight-reduced (≥ 10% loss of maximum historical TBW before tirzepatide) or non-weight-reduced.
• Among patients who switched from therapeutic semaglutide (≥ 1.7 mg weekly for ≥ 1 month), reasons for switching were categorized as nonresponse (< 5% weight loss after ≥ 3 months), weight-loss plateau (≥ 5% loss followed by stabilization for ≥ 3 months), or other.
• The primary outcome was mean percentage of TBW loss at 6 months, comparing weight-reduced vs non-weight-reduced groups. Associations between prior weight loss and subsequent percentage TBW loss on tirzepatide were also assessed.

TAKEAWAY: 

• The analysis included 293 adults (mean age, 52 years; 65% female; mean BMI, 36.15), of whom 133 were weight reduced and 160 were non-weight reduced; 70 had switched from therapeutic-dose semaglutide (28 due to plateau, 33 due to nonresponse, and nine for other reasons).
• Mean additional TBW loss was 7.2% in weight-reduced patients vs 10.3% in non-weight-reduced patients (P < .001); 55% vs 80%, respectively, achieved ≥ 5% TBW loss (P < .001).
• Among patients without type 2 diabetes (T2D; n = 193), weight-reduced patients lost 9% TBW vs 11% in non-weight-reduced patients (P = .013); no significant difference was observed between groups among those with T2D (n = 100).
• Greater pre-tirzepatide weight loss was associated with smaller subsequent weight reductions at 6 months (P < .001).
• Among patients switching from therapeutic-dose semaglutide, those switching due to plateau lost an additional 8.1% TBW vs 2.9% among those switching due to nonresponse (P < .001).

IN PRACTICE: 

“These findings suggest that prior treatment response and clinical context may be more informative for setting expectations than isolated clinical characteristics,” the authors wrote.

SOURCE: 

The study was led by Sarah R. Barenbaum, MD, Comprehensive Weight Control Center, Weill Cornell Medicine, New York. It was published online as a brief cutting-edge report in Obesity.

LIMITATIONS: 

The study was retrospective and conducted at a single center, with a limited 6-month follow-up. Patients had varying prior weight-loss trajectories, and lack of detailed data on the timing, duration, and maintenance of prior weight loss limits conclusions regarding mechanisms such as adaptive thermogenesis.

DISCLOSURES: 

One author received partial support from a grant from the Clinical and Translational Science Center at Weill Cornell Medical College. Another author reported research funding from Novo Nordisk, Eli Lilly and Company, and Viking Therapeutics and advisor/consultant roles with Sun Pharmaceuticals, Eli Lilly and Company, and Novo Nordisk.

This article was created using several editorial tools, including AI, as part of the process. Human editors reviewed this content before publication.