Semaglutide once-weekly: improved efficacy with a new safety warning

Introduction: Semaglutide once-weekly glucagon-like peptide-1 receptor agonist (GLP-1 RA) injection has been approved as an adjunct to diet and exercise to improve glycemic control in type 2 diabetes mellitus (T2DM). Areas Covered: The safety and efficacy of the semaglutide once-weekly injection are reviewed using results from preliminary pharmacology studies and later-phase randomized control trials (RCTs) and meta-analyses. Semaglutide once-weekly is compared to placebo and active comparators for T2DM in the SUSTAIN clinical trial series, with outcomes of: glycemic control, weight loss, major adverse cardiovascular events, and adverse effects. Risk for diabetic retinopathy complications (DRCs) is reviewed in detail, due to significantly higher risk for DRCs seen in SUSTAIN 6. SUSTAIN 6 is the first instance of a GLP-1 RA demonstrating significantly increased risk for DRCs. Semaglutide's current regulatory approvals, practice considerations, and cost-effectiveness compared to similar therapies are also considered. Expert Commentary: Semaglutide demonstrates high glycemic efficacy and favorable safety profile, and reduces the risk for cardiovascular events. Mild to moderate gastrointestinal events and retinopathy complications were more common with semaglutide compared to placebo, though serious adverse events were similar to controls and infrequent. Improved clinical efficacy should be carefully weighed against the risk for GI and retinopathy complications.