To assess the long-term efficacy and safety of saxagliptin in patients with type 2 diabetes mellitus inadequately controlled with thiazolidinedione monotherapy, 565 patients were randomised to saxagliptin (2.5 mg or 5 mg) or placebo added to thiazolidinedione over 76 weeks (24-week short-term + 52-week long-term extension period) in this phase 3, double-blind, placebo-controlled trial; 360 patients completed the study. At 76 weeks, adjusted mean changes from baseline HbA(1C) (repeated measures model; 95% CI) for saxagliptin 2.5 mg, 5 mg, and placebo were -0.59% (-0.75, -0.43), -1.09% (-1.26, -0.93), and -0.20% (-0.39, -0.01), respectively (post hoc and nominal p=0.0019 and p<0.0001 for saxagliptin 2.5 mg and 5 mg vs. placebo, respectively). Adverse event frequency was similar between groups. Confirmed hypoglycaemic events were 1.0% and 0% vs. 0.5% for saxagliptin 2.5 mg and 5 mg vs. placebo, respectively. Results should be interpreted with caution given the proportion of patients who discontinued or required glycaemic rescue therapy during the 76-week course of study. Saxagliptin added to thiazolidinedione provided sustained incremental efficacy vs. placebo with little hypoglycaemia for up to 76 weeks and was generally well tolerated.
Trial registration: ClinicalTrials.gov NCT00295633.