Alogliptin as a third oral antidiabetic drug in patients with type 2 diabetes and inadequate glycaemic control on metformin and pioglitazone: a 52-week, randomized, double-blind, active-controlled, parallel-group study

Aim: To assess the efficacy and safety of adding alogliptin versus uptitrating pioglitazone in patients with type 2 diabetes and inadequate glycaemic control on metformin and pioglitazone. Methods: In this randomized, double‐blind, active‐controlled, parallel‐group study, patients with type 2 diabetes and A1c ≥7.0 and ≤10.0% on metformin (≥1500 mg or maximum tolerated dose; Met) and pioglitazone 30 mg (Pio30) received alogliptin 25 mg (Alo25; n = 404) or pioglitazone 15 mg (n = 399) added to Met+Pio30 for 52 weeks. The primary endpoint was change from baseline (CFB) in A1c at weeks 26 and 52, with sequential testing for non‐inferiority of Met+Pio30+Alo25 at weeks 26 and 52 and then for superiority at week 52. Results: Met+Pio30+Alo25 showed superior glycaemic control versus Met+Pio45 at week 52 least squares (LS) mean CFB in A1c, ?0.70 vs. ?0.29%; p < 0.001]. At week 52, Met+Pio30+Alo25 resulted in greater CFB in A1c regardless of baseline A1c (p < 0.001); higher proportions of patients achieving A1c ≤7.0 (33.2 vs. 21.3%) and ≤6.5% (8.7 vs. 4.3%; p < 0.001); greater CFB in fasting plasma glucose (FPG; LS mean CFB, ?0.8 vs. ?0.2 mmol/L; p < 0.001); and greater improvements in measures of β‐cell function (p < 0.001). Hypoglycaemia incidence was low (Met+Pio30+Alo25, 4.5%; Met+Pio45, 1.5%), mostly mild to moderate, but with two severe events in the Met+Pio30+Alo25 group. No meaningful differences in incidences of individual adverse events were observed between treatments. Conclusions: Adding alogliptin to an existing metformin–pioglitazone regimen provided superior glycaemic control and potentially improved β‐cell function versus uptitrating pioglitazone in patients with type 2 diabetes, with no clinically important differences in safety.