Saxagliptin is non-inferior to glipizide in patients with type 2 diabetes mellitus inadequately controlled on metformin alone: a 52-week randomised controlled trial

Abstract

Aim: To assess the efficacy and safety of saxagliptin vs. glipizide as add-on therapy to metformin in patients with type 2 diabetes mellitus and inadequate glycaemic control on metformin alone.

Methods and patients: A total of 858 patients [age ≥ 18 years; glycated haemoglobin (HbA(1c) ) > 6.5 - 10.0%; on stable metformin doses ≥ 1500 mg/day] were randomised 1 : 1 to saxagliptin 5 mg/day or glipizide up-titrated as needed from 5 to 20 mg/day for 52 weeks. The primary objective was to assess if the change from baseline HbA(1c) achieved with saxagliptin plus metformin was non-inferior to glipizide plus metformin.

Results: The per-protocol analysis demonstrated non-inferiority of saxagliptin vs. glipizide; adjusted mean changes from baseline HbA(1c) were -0.74% vs. -0.80%, respectively; the between-group difference was 0.06% (95% CI, -0.05% to 0.16%). Treatment with saxagliptin vs. glipizide was associated with a significantly smaller proportion of patients with hypoglycaemic events (3.0% vs. 36.3%; p < 0.0001) and a divergent impact on body weight (adjusted mean change from baseline -1.1 kg with saxagliptin vs. 1.1 kg with glipizide; p < 0.0001). There was a significantly smaller rise in HbA(1c) (%/week) from week 24 to 52 with saxagliptin vs. glipizide (0.001% vs. 0.004%; p = 0.04) indicating a sustained glycaemic effect beyond week 24. Excluding hypoglycaemic events, the proportion of patients experiencing adverse events (AEs) was similar (60.0% saxagliptin vs. 56.7% glipizide); treatment-related AEs were less common with saxagliptin vs. glipizide (9.8% vs. 31.2%), attributable to the higher frequency of hypoglycaemia in glipizide patients. Discontinuation rates resulting from AEs were similar (∼4%).

Conclusion: Saxagliptin plus metformin was well tolerated, provided a sustained HbA(1c) reduction over 52 weeks, and was non-inferior to glipizide plus metformin, with reduced body weight and a significantly lower risk of hypoglycaemia.