The glucagon-like peptide 1 receptor agonist albiglutide is superior to placebo in preventing major adverse cardiovascular events in patients with type 2 diabetes mellitus. In the Harmony Outcomes trial, 9,436 patients with diabetes and cardiovascular disease were randomly assigned to a once-weekly subcutaneous injection of albiglutide (30–50 mg) or placebo, in addition to standard care. Over a median duration of 1.6 years, the rate of the primary end point (cardiovascular death, myocardial infarction or stroke) was 7.1% and 9.0% in the albiglutide and placebo groups, respectively (HR 0.78, 95% CI 0.68–0.90, P = 0.0006 for superiority). The rate of adverse events did not differ significantly between the groups.