How do these drugs compare in achieving updated diabetes-related quality measures?
The HEDIS Comprehensive Care quality measures created by the National Committee for Quality Assurance were updated in 2015 to bring them into line with recent clinical guidelines. Very few studies have compared the attainment of quality measures between different classes of antihyperglycemic agents, especially between older and newer agents. The current study by C.A. Patel, et al, is a post-hoc analysis of the CANTATA-SU trial; the objective is to compare the efficacy of canagliflozin and glimepiride in achieving updated diabetes-related quality measures (QMs).
The CANTATA-SU trial was a randomized, double-blind, Phase 3 trial that compared the use of canagliflozin and glimepiride over 104 weeks in patients with T2DM who were not adequately controlled on metformin. Primary outcomes of this analysis were the change in A1C from baseline, as well as the proportion of study population that achieved HbA1c <7.0%, <8.0%, or >9.0%. Secondary outcomes included change in BP from baseline and the proportion of study population that achieved QMs related to BP and body weight. Outcomes were evaluated at 52 and 104 weeks.
A total of 1,452 patients were randomized into one of 3 treatment arms; canagliflozin 100 mg daily, 300 mg daily, or maximally tolerated dose of glimepiride up to 8 mg daily in a 1:1:1 ratio. Baseline characteristics were well balanced between groups. The majority of patients were caucasian, obese, and slightly more than half were male. The mean age was 56 years, mean duration of diabetes was 6.6 years, and mean HbA1c at baseline was 7.8%
Overall, the canagliflozin groups and the glimepiride group had similar rates of QM goal attainment for A1c <7.0% and A1C<8.0%, but there was a statistically significant reduction in the proportion of poorly controlled patients (A1c >9.0%) at 104 weeks in the canagliflozin groups compared with glimepiride. Although glycemic outcomes were similar, the canagliflozin groups achieved statistically significant improvements in attainment of QMs related to blood pressure and weight compared to glimepiride.
Significantly more patients in the canagliflozin groups attained a blood pressure < 140/90 mmHg compared with glimepiride at week 52, and this effect persisted in the high-dose canagliflozin arm at week 104, but was not significant at week 104 in the low-dose canagliflozin arm. Both canagliflozin arms demonstrated a significant decrease in the proportion of patients with a BMI ≥30 kg/m2 at 52 and 104 weeks, while glimepiride had an increase in patients with a BMI ≥30 kg/m2. Additionally there was a statistically significant difference in the proportion of patients who were overweight, but had at least a 10-pound weight loss from baseline in the canagliflozin groups versus glimepiride, which was maintained at both 52 and 104 weeks as well.
In comparison with glimepiride, canagliflozin demonstrated similar achievement of glycemic quality measures, but with a statistically significant improvement in quality measures for blood pressure and weight reduction. However, canagliflozin is often more costly for patients, and therefore less utilized than glimepiride and other sulfonylureas at this time. Additional pharmacoeconomic analyses would be helpful to determine if the increased cost is worth the benefits of using canagliflozin over glimepiride given the additional benefits on weight and blood pressure.
- Patients not achieving adequate glycemic control on metformin monotherapy can attain similar glycemic control with canagliflozin or glimepiride.
- This study demonstrated an increase in the proportion of patients achieving blood pressure and weight quality measures with canagliflozin compared with glimepiride.
- Canagliflozin may be preferable as a second-line agent over glimepiride (or other sulfonuylreas) if obesity or hypertension is a comorbid issue in a patient with type 2 diabetes inadequately controlled on metformin monotherapy.
Patel CA, Bailey RA, Vijapurkar U, Meininger G, Blonde L. A post-hoc analysis of the comparative efficacy of canagliflozin and glimepiride in the attainment of type 2 diabetes-related quality measures. BMC Health Services Research 2016;16:356.
Researched and prepared by Rebecca Tourtellotte, URI College of Pharmacy Pharm.D. Candidate, Class of 2017. Reviewed by Michelle Caetano, Pharm.D., BCPS, BCACP, CDOE, CVDOE.