The Short-Term Cost-Effectiveness of Once-Daily Liraglutide Versus Once-Weekly Exenatide for the Treatment of Type 2 Diabetes Mellitus in the United States

BACKGROUND: Type 2 diabetes mellitus (T2DM) is a chronic metabolic disease with substantial morbidity, mortality, and economic impacts. Glucagon-like peptide-1 (GLP-1) receptor agonists, such as once-daily (QD) liraglutide and once-weekly (QW) exenatide, are FDA-approved treatment for T2DM. Head-to-head trials and meta-analyses comparing these agents have reported clinically meaningful improvements but small differences in glycemic control between both agents. In this study, we calculate and compare the cost-effectiveness implications of these alternative effectiveness outcomes. METHODS: We developed a decision model to evaluate the short-term cost-effectiveness of exenatide QW 2 mg versus liraglutide QD 1.8 mg in T2DM patients, with effectiveness measured as reduction in glycated hemoglobin (HbA1c). In the base case, the model tracks change in HbA1c and direct medical expenditure over a 6-month time horizon. We calculated and compared the cost per 1% reduction in HbA1c of models populated with clinical data from a head-to-head randomized, controlled trial (DURATION-6) and a network meta-analysis. Expenditure inputs were derived from wholesale acquisition costs and published sources. RESULTS: In the base case, 6-month expenditure for the liraglutide and exenatide strategies were $3,509 and $2,618, respectively. Using clinical data from DURATION-6 and the network meta-analysis, the liraglutide strategy had an incremental cost per 1% reduction in HbA1c of $4,773 and $27,179, respectively. The most influential model parameters were drug costs, magnitude of HbA1c reduction in patients on treatment for >1 month, and liraglutide gastrointestinal adverse event rate. In probabilistic sensitivity analyses (PSA) using DURATION-6 data, the exenatide strategy was optimal at willingness-to-pay levels below $4,800 per 1% reduction in HbA1c. In a PSA using meta-analysis data, the exenatide strategy was dominant. CONCLUSIONS: Our modeled results demonstrate that the effectiveness and cost-effectiveness of liraglutide QD 1.8 mg relative to exenatide QW 2 mg depend largely on the chosen source of the clinical data.