Efficacy and safety of alogliptin added to metformin in Japanese patients with type 2 diabetes: a randomized, double‐blind, placebo‐controlled trial with an open‐label, long‐term extension study

Aims To evaluate the efficacy and safety of alogliptin added to metformin versus metformin monotherapy in Japanese patients with type 2 diabetes who achieved inadequate glycaemic control on metformin (500 or 750 mg/day) + diet/exercise. Methods In a randomized, double‐blind trial, 288 patients with type 2 diabetes mellitus T2DM received either 12.5 or 25 mg alogliptin once daily + metformin or placebo + metformin for 12 weeks. Thereafter, 276 patients continued on one of the two alogliptin dosages + metformin in an open‐label extension for 40 weeks. The primary efficacy endpoint in the randomized, double‐blind phase was the change in HbA1c from baseline (week 0) to the end of treatment (week 12). The primary endpoint during the long‐term extension phase was adverse events. Results After 12 weeks both dosages of alogliptin + metformin produced significantly greater changes from baseline in HbA1c than placebo (metformin monotherapy: with changes in LS means − 0.55 and − 0.64% vs. 0.22%, respectively; p < 0.0001). Incidences of adverse effects were comparable between groups, with no increases in hypoglycaemia. Over 52 weeks, there were no safety or tolerability concerns with alogliptin when added to metformin. Conclusions Alogliptin 12.5 and 25 mg once daily was safe and effective when added to metformin (500 or 750 mg/day) in Japanese patients with inadequately controlled type 2 diabetes on metformin alone.