Efficacy and safety of the G protein-coupled receptor 119 agonist DS-8500a in Japanese type 2 diabetes mellitus patients with inadequate glycemic control on sitagliptin: A phase 2 randomized placebo-controlled study

Introduction We evaluated the efficacy and safety of DS-8500a as add-on therapy to sitagliptin in Japanese type 2 diabetes mellitus patients. Materials and Methods This multicenter, randomized, double-blind, placebo-controlled, phase 2 trial randomized patients aged >= 20 years with hemoglobin A1c >= 7.0% and <9.0%, and inadequate glycemic control with sitagliptin 50-mg monotherapy to receive 25 or 75 mg DS-8500a, or a placebo, orally. The primary end-point was change from baseline to day 28 in 24-h weighted mean glucose. Secondary end-points included change from baseline in fasting plasma glucose, 2-h postprandial plasma glucose and lipid profiles. Results Overall, 29, 28 and 27 patients in the placebo, 25- and 75-mg groups, respectively, were analyzed. A significant dose-dependent reduction was observed in 24-h weighted mean glucose (linear: P = 0.0006, saturated at 25 mg: P = 0.0003, responded from 75 mg: P = 0.0176) when compared with the placebo (25 mg: -13.19 mg/dL [-0.73 mmol/L], P = 0.0044 vs placebo and 75 mg: -16.12 mg/dL [-0.89 mmol/L], P = 0.0006 vs placebo). A significant reduction in fasting plasma glucose at 75 mg vs placebo was observed (P < 0.001). At 25 and 75 mg, significant reductions of 2-h postprandial plasma glucose (after breakfast), total cholesterol, low-cholesterol and triglycerides were observed (all P < 0.05), with a (non-significant) trend towards increased high-density lipoprotein cholesterol. Both doses of DS-8500a were well tolerated. There were no significant treatment-emergent adverse events leading to discontinuation during the study. Conclusions DS-8500a was well tolerated, and showed significant glycemic benefits and favorable changes in lipid profile in Japanese type 2 diabetes mellitus patients with inadequate glycemic control with sitagliptin therapy.