Some of the reasons cited for the observed cost efficiencies: better achievement of A1C and composite quality-of-care goals and fewer treatment failures.
When used in combination with metformin and a sulfonylurea, the SGLT2 inhibitor canagliflozin may be more cost- effective than the DPP4 inhibitor sitagliptin, according to the results of a study published recently in the American Journal of Managed Care.
“The results of this 52-week economic analysis suggest that canagliflozin 300 mg may represent a cost-efficient treatment option versus sitagliptin 100 mg for patients with T2DM receiving background therapy of metformin plus a sulfonylurea,” wrote Varun U. Ektare, BPharm, MPH, Pharmerit International, Bethesda, MD, and colleagues. The reasons they cite are “… lower costs; better achievement of A1C, and composite quality-of-care goals including BMI, blood pressure, and LDL-C; and fewer treatment failures.”
The cost-efficacy analysis specifically examined short-term cost-per-outcome for canagliflozin and sitagliptin, both of which are approved for glycemic control of adults with type 2 diabetes.
The study looked at outcomes from 755 patients with inadequately controlled diabetes who participated in a phase III clinical trial. The patients had been randomly assigned to canagliflozin or sitagliptin plus metformin and a sulfonylurea. Results of the study showed that canagliflozin significantly reduced HbA1c compared with sitagliptin at 52 weeks, with a greater percentage of patients assigned to canagliflozin achieving an HbA1C of less than 7%.
In their cost model, the researchers included cost of short-term direct medical and pharmacy costs, as well as costs of treatment for genital mycotic infections and hypoglycemic events.
Botteman and colleagues estimated that the net per-patient per-year costs were lower with canagliflozin ($22,047) than with sitagliptin ($22,263). Total medical costs and drug costs were the largest components of overall expense for both drugs. Looking at just diabetes-related costs, canagliflozin was estimated at approximately $10,449 per patient per year and sitagliptin $10,529 per patient per year.
The researchers also calculated incremental costs per patient who responded to the medication. For example, the average cost per patient who achieved an HbA1c of less than 7% was $46,318 for canagliflozin and $63,068 for sitagliptin.
The researchers noted that since this model used outcomes taken from a clinical trial, it may not reflect outcomes that would occur in a real-world practice.
“Model outcomes such as these provide relatively simple and accessible information to formulary decision makers in the absence of real-world utilization data, focusing on the efficiency of achieving individual and multiple short-term treatment goals that are relevant to payers, providers, and patients,” the researchers wrote.
Ektare VU, Lopez JMS, Martin SC, et al. Cost efficiency of canagliflozin versus sitagliptin for type 2 diabetes mellitus. Am J Manag Care. 2014; published online October 26, 2014.