Introduction Glucagon-like peptide-1 (GLP-1) receptor agonists are used successfully in the treatment of patients with type 2 diabetes as they are associated with low hypoglycemia rates, weight loss and improved glycemic control. This study compared, in the Spanish setting, the cost-effectiveness of liraglutide 1.8 mg versus lixisenatide 20 μg, both GLP-1 receptor agonists, for patients with type 2 diabetes who had not achieved glycemic control targets on metformin monotherapy.MethodsThe IMS CORE Diabetes Model was used to project clinical outcomes and costs, expressed in 2015 Euros, over patient lifetimes. Baseline cohort data and treatment effects were taken from the 26-week, open-label LIRA-LIXI™ trial (NCT01973231). Treatment and management costs of diabetes-related complications were retrieved from published sources and databases. Future benefits and costs were discounted by 3% annually. Sensitivity analyses were conducted.ResultsCompared with lixisenatide 20 μg, liraglutide 1.8 mg was associated with higher life expectancy (14.42 vs. 14.29 years), higher quality-adjusted life expectancy [9.40 versus 9.26 quality-adjusted life years (QALYs)] and a reduced incidence of diabetes-related complications. Higher acquisition costs resulted in higher total costs for liraglutide 1.8 mg (EUR 42,689) than for lixisenatide 20 μg (EUR 42,143), but these were partly offset by reduced costs of treating diabetes-related complications (EUR 29,613 vs. EUR 30,636). Projected clinical outcomes and costs resulted in an incremental cost-effectiveness ratio of EUR 4113 per QALY gained for liraglutide 1.8 mg versus lixisenatide 20 μg.ConclusionsLong-term projections in the Spanish setting suggest that liraglutide 1.8 mg is likely to be cost-effective compared with lixisenatide 20 μg in type 2 diabetes patients who have not achieved glycemic control targets on metformin monotherapy. Liraglutide 1.8 mg presents a clinically and economically attractive treatment option in the Spanish setting.