AstraZeneca today announced results from an observational, retrospective study which found no evidence of increased risk of hospitalization for heart failure (hHF) with saxagliptin, compared with sitagliptin, both of which are dipeptidyl peptidase-4 (DPP-4) inhibitors, in patients with type 2 diabetes. A similar finding was obtained when comparing the overall DPP-4 class to sulfonylureas. The analysis included patients with and without prior cardiovascular disease (CVD), and among those patients without prior cardiovascular disease (CVD), DPP-4 treatment was associated with statistically significant lower risk for hHF compared to treatment with sulfonylureas.
The data were presented during a late-breaker poster session at the 75th Scientific Sessions of the American Diabetes Association (ADA) in Boston, 5-9 June 2015.
“These new data provide valuable real-world information regarding the cardiovascular safety of the DPP-4 inhibitor class in patients with type 2 diabetes,” said Alex Fu, PhD, Principal Investigator for this study and Associate Professor, Georgetown University Medical Center, Washington, D.C. “In particular, the study findings provide new information on the risk of hospitalization for heart failure for DPP-4 inhibitors, and specifically for saxagliptin relative to sitagliptin, within this class.”
The real-world evidence study used a retrospective, observational, new-user cohort design comprised of US inpatient medical, outpatient medical, and outpatient pharmacy insurance claims data for patients with type 2 diabetes from August 2010 to August 2013. Both commercial and Medicare databases were part of the analysis. Analyses of the claims were stratified by the presence or absence of baseline CVD, which was defined as patients having at least one medical claim with any CVD code, and those without CVD. Patients in the comparator groups were matched for demographic, clinical and hHF risk factors using propensity score matching.
For the comparison of saxagliptin versus sitagliptin for the risk of hHF, more than 100,000 patients were included. For patients with baseline CVD, the hazard ratio (HR) was 0.95: 95% confidence interval (CI): 0.70, 1.28. For patients with no baseline CVD, the HR was 0.99: 95% CI: 0.56, 1.75.
For the comparison of DPP-4 inhibitors versus sulfonylureas, more than 200,000 patients were included. For patients with CVD at baseline, the HR was 0.95: 95% CI: 0.78, 1.15. For patients with no baseline CVD, the HR was 0.59: 95% CI: 0.38, 0.89.
Secondary outcomes of this retrospective, observational analysis, including hospitalization for acute myocardial infarction, stroke, unstable angina; coronary revascularization; and a composite of all outcomes together, including hHF, were consistent with the primary findings of this study. While the study observations provide important information, all retrospective claims database studies have inherent limitations that include the potential for bias due to their retrospective non-randomised design and the potential for incomplete or inaccurate claims data.