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

Aim: To assess the efficacy and safety of alogliptin added to pioglitazone versus pioglitazone monotherapy, in Japanese patients with type 2 diabetes who achieved inadequate glycaemic control on pioglitazone plus diet/exercise. Methods: Patients were stabilized on pioglitazone 15 or 30 mg/day plus diet/exercise during a 16-week screening period. Patients with HbA1c of 6.9-10.4% were randomized to 12 weeks' double-blind treatment with alogliptin 12.5 or 25 mg once daily or placebo, added to their stable pioglitazone regimen. The primary endpoint was the change in HbA1c from baseline to week 12. Patients had an option to continue in a 40-week, open-label extension study, with those originally randomized to alogliptin remaining on the same dosage regimen while patients treated with placebo were randomly allocated to alogliptin 12.5 or 25 mg (added to their stable pioglitazone). Results: The change from baseline in HbA1c after 12 weeks was significantly greater with alogliptin 12.5 mg added to pioglitazone and alogliptin 25 mg added to pioglitazone than with placebo added to pioglitazone (-0.91 and -0.97% vs. -0.19%; p < 0.0001). Responder rates (HbA1c <6.9% and HbA1c <6.2%) and changes in fasting and postprandial blood glucose levels showed a similar positive trend in terms of glycaemic control. The benefits seen with alogliptin were sustained during the 40-week extension period. Alogliptin added to pioglitazone was generally well tolerated; hypoglycaemia was infrequent and increases in body weight were minor. Conclusions: Once-daily alogliptin was effective and generally well tolerated when given as add-on therapy to pioglitazone in Japanese patients with type 2 diabetes who achieved inadequate glycaemic control on pioglitazone plus lifestyle measures. Clinical benefits were maintained for 52 weeks.