Cost-Effectiveness of Canagliflozin versus Sitagliptin as Add-on to Metformin in Patients with Type 2 Diabetes Mellitus in Mexico

Objective: To assess the cost-effectiveness of canagliflozin versus sitagliptin for the treatment of type 2 diabetes mellitus (T2DM) as an add-on to metformin in Mexico. Methods: A validated model (Economic and Health Outcomes [ECHO]-T2DM) was used to estimate the cost-effectiveness of canagliflozin 300 or 100 mg versus sitagliptin 100 mg in patients with T2DM inadequately controlled on metformin monotherapy. Data from a head-to-head, phase III clinical trial, including patients’ baseline demographic characteristics, biomarker values, and treatment effects, were used to simulate outcomes and resource use over 20 years from the perspective of the Mexican health care system. Costs of complications and adverse events were tailored to the Mexican setting and discounted at 5%. Cost-effectiveness was assessed using willingness-to-pay thresholds equivalent to 1 times the gross domestic product per capita (locally perceived to be “very cost-effective”) and 3 times the gross domestic product per capita (locally perceived to be “cost-effective”) on the basis of recommendations of the Mexican government and the World Health Organization. Results: Owing primarily to better glycated hemoglobin (HbA1c), body weight, and systolic blood pressure values, canagliflozin 300 and 100 mg were associated with an incremental benefit of 0.16 and 0.06 quality-adjusted life-years (QALYs) versus sitagliptin 100 mg, respectively, over 20 years. The mean differences in cost for canagliflozin 300 and 100 mg versus sitagliptin 100 mg were Mexican pesos (MXP) 1797 (US $134) and MXP 7262 (US $540), respectively, resulting in a cost per QALY gained of MXP 11,210 (US $834) and MXP 128,883 (US $9590), respectively. Both of these cost-effectiveness ratios are below the very cost-effective willingness-to-pay threshold in Mexico. The general finding that canagliflozin is cost-effective versus sitagliptin in Mexico was supported by sensitivity analyses. Conclusion: In Mexico, both doses of canagliflozin are likely to be cost-effective versus sitagliptin in patients with T2DM who have inadequate glucose control on metformin, primarily because of better biomarker control and higher QALYs.