Effects of saxagliptin added to sub-maximal doses of metformin compared with uptitration of metformin in type 2 diabetes: The PROMPT study

Objective: The PROMPT study compared efficacy and tolerability of two treatment intensification strategies: adding saxagliptin or uptitrating metformin monotherapy, in patients with type 2 diabetes (T2D) and inadequate glycaemic control on a sub-maximal metformin dose. Research design and methods: In this double-blind, 24-week study, metformin-tolerant patients with T2D on metformin monotherapy were randomised to receive fixed-dose metformin 1500mg/day, plus either add-on saxagliptin 5mg/day (SAXA-MET) or a two-step metformin uptitration (MET-UP) to a maximum dose (2500mg/day). Clinical trial registration: NCT01006590. Main outcome measures: Primary: absolute change from baseline in glycated haemoglobin A1c (HbA1c) (Week 24). Secondary: proportion of patients achieving a therapeutic glycaemic response (Week 24); change from baseline in fasting plasma glucose (Week 24); safety and tolerability. Exploratory analyses comprised three patient-related questionnaires, including the validated 5-dimension Digestive Health Status Index (DHSI). Results: A total of 286 patients were randomised: (SAXA-MET: 147; MET-UP: 139). Baseline mean (SD) HbA1c: 7.71 (0.85; SAXA-MET); 7.80 (0.82; MET-UP). Adjusted mean reductions from baseline in HbA1c (Week 24):-0.47 (SAXA-MET);-0.38 (MET-UP); mean (95 CI) difference in treatment effect,-0.10 (-0.26, 0.07); p0.260. The proportion of patients (95 CI) achieving a therapeutic glycaemic response (HbA1c