Reply to “New IFSO/ASMBS Indications for Metabolic and Bariatric Surgery? Yes, After Failure of Best Nonsurgical Therapy”

Obesity is a global health challenge with few pharmacologic options. Whether adults with obesity can achieve weight loss with once-weekly semaglutide at a dose of 2.4 mg as an adjunct to lifestyle intervention has not been confirmed.

Obesity is a chronic disease that results in substantial global morbidity and mortality. The efficacy and safety of tirzepatide, a novel glucose-dependent insulinotropic polypeptide and glucagon-like peptide-1 receptor agonist, in people with obesity are not known.

The STEP 5 trial assessed the efficacy and safety of once-weekly subcutaneous semaglutide 2.4 mg versus placebo (both plus behavioral intervention) for long-term treatment of adults with obesity, or overweight with at least one weight-related comorbidity, without diabetes. The co-primary endpoints were the percentage change in body weight and achievement of weight loss of ≥5% at week 104. Efficacy was assessed among all randomized participants regardless of treatment discontinuation or rescue intervention. From 5 October 2018 to 1 February 2019, 304 participants were randomly assigned to semaglutide 2.4 mg (n = 152) or placebo (n = 152), 92.8% of whom completed the trial (attended the end-of-trial safety visit). Most participants were female (236 (77.6%)) and white (283 (93.1%)), with a mean (s.d.) age of 47.3 (11.0) years, body mass index of 38.5 (6.9) kg m–2 and weight of 106.0 (22.0) kg. The mean change in body weight from baseline to week 104 was −15.2% in the semaglutide group (n = 152) versus −2.6% with placebo (n = 152), for an estimated treatment difference of −12.6 %-points (95% confidence interval, −15.3 to −9.8; P < 0.0001). More participants in the semaglutide group than in the placebo group achieved weight loss ≥5% from baseline at week 104 (77.1% versus 34.4%; P < 0.0001). Gastrointestinal adverse events, mostly mild-to-moderate, were reported more often with semaglutide than with placebo (82.2% versus 53.9%). In summary, in adults with overweight (with at least one weight-related comorbidity) or obesity, semaglutide treatment led to substantial, sustained weight loss over 104 weeks versus placebo. NCT03693430