Effect of vildagliptin as add-on therapy to a low-dose metformin

AIM:To evaluate the efficacy and safety of the addition of vildagliptin to low-dose metformin and compare it to an uptitration of metformin in type 2 diabetes mellitus(T2DM) patients who have inadequate control with metformin monotherapy.METHODS:Eligible patients were randomized to receive vildagliptin 100 mg qd or metformin(500 mg qd for 2 wk and then 500 mg bid) added to open label me tformin 500 mg bid for the 24 wk.The primary endpoi nt was baseline to endpoint hemoglobin A1c(HbA1c) change.RESULTS:The adjusted mean change from baseline in HbA1c at the 24th wk was-0.51% in the vildagliptin/metformin group(mean baseline HbA1c:7.4%) and-0.37% in the metformin monothera py group(mean baseline HbA1c:7.3%).The mean diffe rence was-0.14% with 95% Confidence Interval(-0.24%,-0.05%).As non-inf e riority(margin of 0.4%) was achieved,a test for superiority was performed.This test showed statistically significant superiority of the combination over monotherapy group(P = 0.002).Gastrointestinal(GI) adverse events were signif icantly more frequent in the metformin group than the combin ation group(21.0% vs 15.4%,P = 0.032).CONCLUSION:In patients with T2DM inadequately controlled with metformin up to 1000 mg daily,the addition of vildagliptin 100 mg daily achieved larger HbA1c reduction with fewer GI events than with increa sing the metformin dose.