Aims/hypothesis  

Type 2 diabetes is difficult to manage in patients with a long history of disease requiring insulin therapy. Moreover, addition of most currently available oral antidiabetic agents increases the risk of hypoglycaemia. Vildagliptin is a dipeptidyl peptidase-IV inhibitor, which improves glycaemic control by increasing pancreatic beta cell responsiveness to glucose and suppressing inappropriate glucagon secretion. This study assessed the efficacy and tolerability of vildagliptin added to insulin therapy in patients with type 2 diabetes.

Materials and methods  

This was a multicentre, 24-week, double-blind, randomised, placebo-controlled, parallel-group study in patients with type 2 diabetes that was inadequately controlled (HbA_1c = 7.5–11%) by insulin. Patients received vildagliptin (n = 144; 50 mg twice daily) or placebo (n = 152) while continuing insulin therapy.

Results  

Baseline HbA_1c averaged 8.4 ± 0.1% in both groups. The adjusted mean change from baseline to endpoint (AMΔ) in HbA_1c was −0.5 ± 0.1% and −0.2 ± 0.1% in patients receiving vildagliptin or placebo, respectively, with a significant between-treatment difference (p = 0.01). In patients aged ≥65 years, the AMΔ HbA_1c was −0.7 ± 0.1% in the vildagliptin group vs −0.1 ± 0.1% in the placebo group (p < 0.001). The incidence of adverse events was similar in the vildagliptin (81.3%) and placebo (82.9%) groups. However, hypoglycaemic events were less common (p < 0.001) and less severe (p < 0.05) in patients receiving vildagliptin than in those receiving placebo.

Conclusions/interpretation  

Vildagliptin decreases HbA_1c in patients whose type 2 diabetes is poorly controlled with high doses of insulin. Addition of vildagliptin to insulin therapy is also associated with reduced confirmed and severe hypoglycaemia. ClinicalTrials.gov ID no.: NCT 00099931.