INTRODUCTION: The relative efficacy and safety of tirzepatide was compared with glucagon-like peptide 1 receptor agonists (GLP-1 RAs) in patients with type 2 diabetes mellitus (T2DM) treated with basal insulin using a network meta-analysis (NMA). METHODS: A systematic literature review was performed to identify randomized controlled trials of GLP-1 RAs in patients with T2DM treated with insulin and an antihyperglycaemic drug. For the NMA, studies included trials with 100% of patients treated with basal insulin background therapy with a titration scheme comparable to the SURPASS-5 trial. The following data were extracted for efficacy and safety assessment at the primary endpoint of each study: changes from baseline in glycated haemoglobin (HbA1c) and body weight and the incidence of nausea, vomiting or diarrhoea, hypoglycaemia, and patients discontinuing treatment because of adverse events. In this study, a comparative analysis of tirzepatide was performed with the GLP-1 RAs dulaglutide, exenatide, and lixisenatide in addition to placebo. RESULTS: A total of six studies were included across the analyses. Tirzepatide 5, 10, and 15 mg showed statistically significant, greater reductions in HbA1c and body weight at the primary endpoint versus all GLP-1 RA comparators and placebo. Tirzepatide 5, 10, and 15 mg showed a statistically significant, higher likelihood of experiencing nausea compared with those who received placebo or exenatide 2 mg
no statistically significant differences were observed when compared with all other GLP-1 RA comparators. No statistically significant differences were observed in the proportions of patients who discontinued treatment because of adverse events when tirzepatide 5, 10, and 15 mg were compared with GLP-1 RA comparators, apart from tirzepatide 10 and 15 mg versus placebo. CONCLUSION: Tirzepatide demonstrated statistically significantly greater reductions in HbA1c and body weight when compared with selected GLP-1 RAs and placebo in patients with T2DM treated with basal insulin. Overall, the safety profile of tirzepatide was similar to that of GLP-1RAs.