Dutogliptin, a selective DPP4 inhibitor, improves glycaemic control in patients with type 2 diabetes: a 12-week, double-blind, randomized, placebo-controlled, multicentre trial.

AIM: To determine efficacy and tolerability of dutogliptin, a dipeptidyl peptidase 4 (DPP4) inhibitor, in patients with type 2 diabetes mellitus. METHODS: This was a 12-week, multicentre, randomized, double-blind, placebo-controlled trial in 423 patients with type 2 diabetes with suboptimal metabolic control. Following a 2-week single-blind placebo run-in, patients aged 18-75 years with a body mass index of 25-48 kg/m(2) and baseline HbA1c of 7.3-11.0% were randomized 2:2:1 to receive once-daily oral therapy with either dutogliptin (400 or 200 mg) or placebo on a background medication of either metformin alone, a thiazolidinedione (TZD) alone or a combination of metformin plus a TZD. RESULTS: Average HbA1c at baseline was 8.4%. Administration of dutogliptin 400 and 200 mg for 12 weeks decreased HbA1c by -0.52% (p < 0.001) and -0.35% (p = 0.006), respectively (placebo-corrected values), with absolute changes in HbA1c for the 400 mg, 200 mg and placebo groups of -0.82, -0.64 and -0.3%, respectively. The proportion of patients achieving an HbA1c < 7% was 27, 21 and 12% at dutogliptin doses of 400 and 200 mg or placebo, respectively (p = 0.008 for comparison of 400 mg vs. placebo). Fasting plasma glucose (FPG) levels were significantly reduced in both active treatment groups compared to placebo: the placebo-corrected difference was -1.00 mmol/l (p < 0.001) for the 400 mg group and -0.88 mmol/l (p = 0.003) for the 200 mg group. Dutogliptin caused significantly greater reductions in postprandial glucose AUC (0-2h) in both the 400 and 200 mg groups (placebo corrected values -2.58 mmol/l/h, p < 0.001 and -1.63 mmol/l/h, p = 0.032, respectively). In general, patients tolerated the study drug well. There were minor, not clinically meaningful differences in adverse events (AEs) between dutogliptin-treated patients and placebo controls, and 60% of all reported AEs were mild. Vital signs and body weight were stable, and routine safety laboratory parameters did not change compared with placebo. Trough ex vivo DPP4 inhibition at the end of the 12-week treatment period was 80 and 70%, at the 400 and 200 mg doses of dutogliptin, respectively. CONCLUSIONS: Dutogliptin treatment for 12 weeks improved glycaemic control in patients with type 2 diabetes who were on a background medication of metformin, a TZD or metformin plus a TZD. Tolerability was favourable for both doses tested. The 400 mg dose of dutogliptin resulted in larger changes of HbA1c and FPG and more subjects reached an HbA1c target of < 7% than the 200 mg dose.

The dipeptidyl peptidase-4 inhibitor PHX1149 improves blood glucose control in patients with type 2 diabetes mellitus.

AIM: To determine the efficacy and tolerability of PHX1149, a novel dipeptidyl peptidase-4 (DPP4) inhibitor, in patients with type 2 diabetes. METHODS: This is a multicentre, randomized, double-blind, placebo-controlled, 4-week study in patients with type 2 diabetes with suboptimal metabolic control. Patients with a baseline haemoglobin A(1c) (HbA(1c)) of 7.3 to 11.0% were randomized 1 : 1 : 1 : 1 to receive once-daily oral therapy with either PHX1149 (100, 200 or 400 mg) or placebo; patients were on a constant background therapy of either metformin alone or metformin plus a glitazone. RESULTS: Treatment with 100, 200 or 400 mg of PHX1149 significantly decreased postprandial glucose area under the curve AUC(0-2 h) by approximately 20% (+0.11 +/- 0.50, -2.08 +/- 0.51, -1.73 +/- 0.49 and -1.88 +/- 0.48 mmol/l x h, respectively, for placebo and 100, 200 and 400 mg (p = 0.002, 0.008 and 0.004 vs. placebo). Postprandial AUC(0-2 h) of intact glucagon-like peptide-1, the principal mediator of the biological effects of DPP4 inhibitors, was increased by 3.90 +/- 2.83, 11.63 +/- 2.86, 16.42 +/- 2.72 and 15.75 +/- 2.71 pmol/l x h, respectively, for placebo and 100, 200 and 400 mg (p = 0.053, 0.001 and 0.002 vs. placebo). Mean HbA(1c) was lower in all dose groups; the placebo-corrected change in the groups receiving 400 mg PHX1149 was -0.28% (p = 0.02). DPP4 inhibition on day 28 was 53, 73 and 78% at 24 h postdose in the groups receiving 100, 200 and 400 mg PHX1149, respectively. There were no differences in adverse events between PHX1149-treated and placebo subjects. CONCLUSIONS: Addition of the DPP4 inhibitor PHX1149 to a stable regimen of metformin or metformin plus a glitazone in patients with type 2 diabetes was well tolerated and improved blood glucose control.