Cost-Effectiveness Analysis of Empagliflozin in Comparison to Sitagliptin and Saxagliptin Based on Cardiovascular Outcome Trials in Patients with Type 2 Diabetes and Established Cardiovascular Disease

Introduction In the cardiovascular outcome trials (CVOT) EMPA-REG OUTCOME, TECOS and SAVOR-TIMI 53, empagliflozin [sodium/glucose cotransporter 2 (SGLT2) inhibitor], sitagliptin and saxagliptin [both dipeptidyl peptidase 4 (DPP4) inhibitors] + standard of care (SoC) were compared to SoC in patients with type 2 diabetes and established cardiovascular disease (CVD). This study assessed the cost-effectiveness (CE) of empagliflozin + SoC in comparison to sitagliptin + SoC and saxagliptin + SoC based on the respective CVOT. Methods The IQVIA Core Diabetes Model (CDM) was calibrated to reproduce the CVOT outcomes. EMPA-REG OUTCOME baseline characteristics and CVOT specific treatment effects on risk factors for cardiovascular disease [glycated haemogloblin A1c (HbA1c), body mass index (BMI), blood pressure, lipids] were applied. Three-year observed cardiovascular events of empagliflozin + SoC versus sitagliptin + SoC and saxagliptin + SoC were derived from EMPA-REG OUTCOME and an indirect treatment comparison. Relative risk (RR) adjustments to calibrate the CDM were estimated after consecutive attempts of running the model until the observed and CDM-predicted outcomes matched closely. The drug-specific treatment effects were considered up until treatment switch (when HbA1c reached 8.5%), after which, the United Kingdom Prospective Diabetes Study (UKPDS) 82 risk equations predicted events based on co-existing risk factors and treatment intensification to basal-bolus insulin were applied. The analysis was conducted from the perspective of the UK National Health Service. Costs and quality of life data were derived from UK national sources and published literature. A 50-year time horizon and discount rate of 3.5% were applied. Results The CDM projected quality-adjusted life years (QALYs) of 6.408, 5.917 and 5.704 and total costs of 50,801 GBP, 47,627 GBP and 48,071 GBP for empagliflozin + SoC, sitagliptin + SoC and saxagliptin + SoC, respectively. The incremental CE ratio (ICER) of empagliflozin + SoC versus sitagliptin + SoC and saxagliptin + SoC was 6464 GBP/QALY and 3878 GBP/QALY, respectively. One-way and probabilistic sensitivity analyses demonstrated the robustness of the results. Conclusion Results suggest that empagliflozin + SoC is cost-effective compared to sitagliptin + SoC and saxagliptin + SoC at a willingness to pay threshold of 20,000 GBP/QALY. Funding Boehringer Ingelheim International GmbH.