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 × 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 × 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.