Twelve- and 52-Week Efficacy of the Dipeptidyl Peptidase IV Inhibitor LAF237 in Metformin-Treated Patients With Type 2 Diabetes

Abstract

OBJECTIVE—To assess the 12- and 52-week efficacy of the dipeptidyl peptidase IV inhibitor LAF237 versus placebo in patients with type 2 diabetes continuing metformin treatment. RESEARCH DESIGN AND METHODS—We conducted a 12-week, randomized, double-blind, placebo-controlled trial in 107 patients with type 2 diabetes with a 40-week extension in those completing the core study and agreeing, together with the investigator, to extend treatment to 1 year. Placebo (n = 51) or LAF237 (50 mg once daily, n = 56) was added to ongoing metformin treatment (1,500–3,000 mg/day). HbA_1c and fasting plasma glucose (FPG) were measured periodically, and standardized meal tests were performed at baseline, week 12, and week 52. RESULTS—In patients randomized to LAF237, baseline HbA_1c averaged 7.7 ± 0.1% and decreased at week 12 (Δ = −0.6 ± 0.1%), whereas HbA_1c did not change from a baseline of 7.9 ± 0.1% in patients given placebo (between-group difference in ΔHbA_1c = −0.7 ± 0.1%, P < 0.0001). Mean prandial glucose and FPG were significantly reduced in patients receiving LAF237 versus placebo by 2.2 ± 0.4 mmol/l (P < 0.0001) and 1.2 ± 0.4 mmol/l (P = 0.0057), respectively, but plasma insulin levels were not affected. At end point of the extension, the between-group differences in change in mean prandial glucose, insulin, and FPG were −2.4 ± 0.6 mmol/l (P = 0.0001), 40 ± 16 pmol/l (P = 0.0153), and −1.1 ± 0.5 mmol/l (P = 0.0312), respectively. HbA_1c did not change from week 12 to week 52 in LAF237-treated patients (n = 42) but increased in participants given placebo (n = 29). The between-group difference in ΔHbA_1c after 1 year was −1.1 ± 0.2% (P < 0.0001). CONCLUSIONS—Data from this study demonstrate that LAF237 effectively prevents deterioration of glycemic control when added to metformin monotherapy in type 2 diabetes.