Improved glycaemic control with dipeptidyl peptidase-4 inhibition in patients with type 2 diabetes: vildagliptin (LAF237) dose response

OBJECTIVE: A novel treatment option for diabetic patients is the enhancement of incretin hormone activity by inhibition of the enzyme dipeptidyl peptidase-4 (DPP-4). This study was designed to establish a dose of the DPP-4-inhibitor vildagliptin (LAF237) that was effective in reducing HbA1c levels and was safe and well tolerated in patients with type 2 diabetes. PATIENTS AND METHODS: The study of 279 patients with type 2 diabetes consisted of a 4-week run-in phase where patients received placebo and a 12-week active treatment phase where they received one of the following dosages of vildagliptin: 25 mg twice daily, 25, 50 or 100 mg once daily (qd), or placebo. RESULTS: There was a statistically significant reduction in HbA1c levels in the vildagliptin 50 mg qd (p=0.003) and 100 mg qd groups (p=0.004) compared with the placebo group. The mean 4-h postprandial glucose level was significantly reduced from placebo in the vildagliptin 50 mg qd group (p = 0.012) and mean 4-h postprandial insulin was significantly increased from baseline vs. placebo in the vildagliptin 100 mg qd group (p=0.022). The assessment of beta-cell function (HOMA-B) was significantly increased in the vildagliptin 100 mg qd treatment group (p=0.007). The incidence of adverse events was similar in all treatment groups including placebo. CONCLUSIONS: Vildagliptin, at 50 and 100 mg qd, was effective in reducing HbA1c levels compared with placebo in patients with type 2 diabetes. Vildagliptin at dosages up to 100 mg qd appeared safe and well tolerated.