Efficacy and safety of once-weekly glucagon-like peptide-1 receptor agonists compared with exenatide and liraglutide in type 2 diabetes: a systemic review of randomised controlled trials

Background Once-weekly glucagon-like peptide-1 receptor agonists (GLP-1RAs) have shown promising results in the treatment of type 2 diabetes. Herein, we compared the efficacy and safety of once-weekly GLP-1RAs with exenatide and liraglutide separately. Methods We systematically surveyed the pertinent literature using various databases. The randomised controlled trials that compared once-weekly GLP-1RAs with exenatide and liraglutide in type 2 diabetes were included. Our main end-points were control of glycaemia, body weight, hypoglycaemia and gastrointestinal adverse events (AEs). Results Our analysis included eight trials involving 5531 patients. Exenatide-long-acting release (LAR), dulaglutide and taspoglutide were more effective than twice-daily exenatide in reducing glycosylated haemoglobin A1c (HbA1c) and fasting blood glucose (FBG) levels and achieving HbA1c targets (< 7.0% and ≤ 6.5%). Liraglutide was as effective as dulaglutide and more effective than exenatide-LAR and albiglutide in controlling glycaemia. With regard to the effectiveness in decreasing body weight, exenatide-LAR, dulaglutide and taspoglutide were similar to exenatide whereas exenatide-LAR, dulaglutide and albiglutide were inferior to liraglutide. Once-weekly GLP-1RAs, exenatide and liraglutide resulted in a similar incidence of hypoglycaemia and of gastrointestinal, serious, or other AEs. Conclusions Once-weekly GLP-1RAs were more effective in controlling glycaemia and equally effective in decreasing body weight than twice-daily exenatide but were inferior to liraglutide in controlling these two parameters (dulaglutide was similar with liraglutide in controlling glycaemia). Once-weekly GLP-1RAs, exenatide and liraglutide had a similar risk of causing AEs.