Efficacy and safety of once-weekly semaglutide versus once-daily sitagliptin as add-on to metformin in patients with type 2 diabetes in SUSTAIN China: A 30-week, double-blind, phase 3a, randomized trial

Aim: To evaluate the efficacy and safety of once-weekly subcutaneous semaglutide, a glucagon-like peptide-1 (GLP-1) analogue, versus once-daily sitagliptin as add-on to metformin in patients with type 2 diabetes (T2D) in a multiregional clinical trial. Materials and Methods: In the 30-week, randomized, double-blind, double-dummy, active comparator SUSTAIN China trial, 868 adults with T2D inadequately controlled on metformin (HbA1c 7.0%-10.5%) were randomized to receive once-weekly semaglutide 0.5 mg (n = 288), semaglutide 1.0 mg (n = 290) or once-daily sitagliptin 100 mg (n = 290). The primary and confirmatory secondary endpoints were change from baseline to week 30 in HbA_1c and body weight, respectively. Results: The trial enrolled ~70% (605/868) of the patients in China, and the remaining patients from four other countries, including the Republic of Korea. Both doses of semaglutide were superior to sitagliptin in reducing HbA_1c and body weight after 30 weeks of treatment. The odds of achieving target HbA_1c of less than 7.0% (53 mmol/mol), weight loss of 5% or higher, or 10% or higher, and the composite endpoint of HbA_1c less than 7.0% (53 mmol/mol) without severe or blood glucose-confirmed symptomatic hypoglycaemia no weight gain, were all significantly higher with both semaglutide doses compared with sitagliptin. The safety profile for semaglutide was consistent with the known class effects of GLP-1 receptor agonists (RAs). Consistent efficacy and safety findings were seen in the Chinese subpopulation. Conclusions: Once-weekly semaglutide was superior to sitagliptin in improving glycaemic control and reducing body weight in patients with T2D inadequately controlled on metformin. The safety and tolerability profiles were consistent with those of semaglutide and other GLP-1 RAs. Semaglutide is an effective once-weekly treatment option for the Chinese population.