Efficacy and safety of teneligliptin added to glimepiride in Japanese patients with type 2 diabetes mellitus: a randomized, double-blind, placebo-controlled study with an open-label, long-term extension

Aims To assess the efficacy and safety of teneligliptin in combination with glimepiride in Japanese patients with type 2 diabetes mellitus (T2DM) inadequately controlled with glimepiride monotherapy. Methods In the initial 12-week, double-blind, placebo-controlled, parallel-group period, 194 patients [haemoglobin A1c (HbA1c): 8.4 +/- 0.8%; fasting plasma glucose (FPG): 164.2 +/- 28.1 mg/dl] were randomized to either teneligliptin 20 mg or placebo once daily while continuing stable glimepiride therapy. This randomized period was then followed by a 40-week, open-label period, where all patients received teneligliptin once daily. The primary endpoint was the change in HbA1c from baseline to week 12. Results Teneligliptin reduced HbA1c significantly compared with placebo at week 12. The placebo-subtracted change in HbA1c was -1.0 +/- 0.1% [least-squares (LS) mean +/- s.e., p < 0.001]. Teneligliptin also significantly reduced FPG and 2-h postprandial glucose (PPG) as compared with placebo at week 12; the placebo-subtracted changes were -27.1 +/- 3.2 and -49.1 +/- 6.2 mg/dl (LS mean +/- s.e., both p < 0.001), respectively. The blood glucose-lowering effects were sustained throughout the 40-week open-label period. The incidence rates of adverse events and adverse drug reactions, including hypoglycaemia, during the double-blind randomized period were similar in both groups. Therefore, teneligliptin was generally well tolerated when used in combination with glimepiride. Conclusions The addition of teneligliptin was effective and generally well tolerated in Japanese patients with T2DM inadequately controlled with glimepiride monotherapy. The improvements in glycaemic control were maintained for up to 52 weeks.