Novo Nordisk’s STEP UP trial at ECO 2026: Semaglutide 7.2 mg delivers 20.7% weight loss in obesity, with 84% from fat mass and preserved muscle function. Early responders hit 27.7%.
At the European Congress on Obesity (ECO) 2026, Novo Nordisk presented new sub-analyses from the Phase 3 STEP UP trial (NCT05646706), evaluating once-weekly semaglutide 7.2 mg in adults with obesity without type 2 diabetes. The trial compared semaglutide 7.2 mg, semaglutide 2.4 mg, and placebo in more than 1,400 participants over 72 weeks.
Participants receiving semaglutide 7.2 mg achieved an average weight reduction of 20.7%, equivalent to approximately 23 kg from a baseline average weight of 113 kg. Those receiving semaglutide 2.4 mg lost 17.5% of body weight, while placebo recipients lost 2.4%. The safety and tolerability profile of the investigational 7.2 mg dose was consistent with the lower approved dose, with gastrointestinal events reported most frequently, in line with prior STEP trials.
A separate exploratory analysis examined “early responders,” defined as participants who lost at least 15% of body weight within the first 24 weeks of treatment. Early responders represented 27% of participants receiving semaglutide 7.2 mg and 21% of those receiving semaglutide 2.4 mg.
By week 72, early responders in the 7.2 mg group achieved an average weight loss of 27.7%, compared with 24.8% in the 2.4 mg group. Participants who did not meet the early-response threshold still experienced clinically meaningful reductions, with average losses of 15.4% and 13.2% in the 7.2 mg and 2.4 mg groups, respectively.
Dr. Dror Dicker, associate clinical professor of Internal Medicine at Tel-Aviv University, Israel, noted that the findings underscore obesity as a chronic disease needing long-term, individualized therapy, with early weight loss predicting greater reductions yet non-early responders still benefit substantially from semaglutide.
Another STEP UP sub-analysis evaluated body composition in a subgroup of 55 participants using MRI imaging. Results showed that 84% of total weight loss was attributable to reductions in fat mass, with abdominal visceral fat declining by more than 30%. Muscle mass decreased by approximately 10% relative to baseline muscle mass, but muscle quality improved, as indicated by reductions in muscle fat content.
Functional muscle strength was preserved, based on performance in a 30-second sit-to-stand test, which remained stable across semaglutide and placebo groups. Investigators concluded that the findings support favorable changes in body composition alongside preservation of muscle function during significant weight reduction.
Emil Kongshøj Larsen, Novo Nordisk’s EVP and head of International Operations, stated that these analyses support higher-dose Wegovy’s potential for substantial weight loss, primarily via fat reduction while preserving muscle function in people with obesity
Wegovy® (semaglutide) is approved as a once-weekly injection in multiple markets, including FDA and EMA approvals for chronic weight management in adults with obesity or overweight with at least one weight-related comorbidity. The therapy also holds approvals in certain indications related to cardiovascular risk reduction and pediatric obesity management.
The STEP UP program, comprising STEP UP and STEP UP T2D, is designed to evaluate the efficacy and safety of semaglutide 7.2 mg in people with obesity with or without type 2 diabetes. The primary objective of the STEP UP trial was to demonstrate superiority of semaglutide 7.2 mg over placebo for weight loss after 72 weeks of treatment.
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