Efficacy and safety of combination therapy with vildagliptin and metformin versus metformin uptitration in Chinese patients with type 2 diabetes inadequately controlled with metformin monotherapy: a randomized, open-label, prospective study (VISION).

AIMS: To compare the efficacy and safety of combination of vildagliptin and metformin therapy with metformin uptitration in Chinese patients with type 2 diabetes (T2DM) inadequately controlled with low-dose metformin.

METHODS: In this 24-week prospective, randomized, multicentre, open-label study, patients with T2DM inadequately controlled with metformin ≤1000 mg daily were divided 1 : 1 : 1 : 1 into four prespecified subgroups based on age and body mass index (BMI). Patients in each subgroup were randomized 5 : 1 to receive either vildagliptin (50 mg twice daily) plus metformin [500 mg twice daily; vildagliptin and low-dose metformin (VLDM) group] or metformin uptitration [1000 mg twice daily; high-dose metformin (HDM) group]. The primary endpoint was change in glycated haemoglobin (HbA1c) from baseline at week 24. The key secondary endpoints included percentage of patients achieving target HbA1c without adverse gastrointestinal (GI) events and mean change in fasting plasma glucose (FPG) from baseline to week 24.

RESULTS: A total of 3084 patients were randomized. HbA1c reduction of 0.54% at week 24 in the VLDM group was non-inferior and statistically superior compared with 0.40% in the HDM group (P < 0.0001). VLDM's non-inferiority to HDM was confirmed in the four subgroups and its superiority was shown for all subgroups (p < 0.05) except for the subgroup of patients aged <60 years with a BMI of ≥24 kg/m(2) . Compared with HDM, VLDM significantly increased the percentage of patients achieving HbA1c ≤6.5% and HbA1c ≤6.5% without GI events. FPG levels in the VLDM group were lower at week 24 numerically than in the HDM group. The two treatment arms had similar safety profiles.

CONCLUSIONS: VLDM was non-inferior and statistically superior to HDM in glycaemic control in Chinese patients with T2DM inadequately controlled with low-dose metformin.