Vildagliptin add-on to metformin produces similar efficacy and reduced hypoglycaemic risk compared with glimepiride, with no weight gain: results from a 2-year study

Methods: A randomized, double-blind, active-comparator study of patients with type 2 diabetes mellitus inadequately controlled (HbA1c 6.5-8.5%) by metformin monotherapy. Patients received vildagliptin (50 mg twice daily) or glimepiride (up to 6 mg/day) added to metformin. Results: In all, 3118 patients were randomized (vildagliptin, n = 1562; glimepiride, n = 1556). From similar baseline values (7.3%), after 2 years adjusted mean (s.e.) change in HbA1c was comparable between vildagliptin and glimepiride treatment: -0.1% (0.0%) and -0.1% (0.0%), respectively. The primary objective of non-inferiority was met. A similar proportion of patients reached HbA1c < 7% (36.9 and 38.3%, respectively), but with vildagliptin more patients reached this target without hypoglycaemia (36.0% vs. 28.8%; p = 0.004). The initial response (IR) was sustained for a mean (s.d.) of 309 (244) days with vildagliptin versus 270 (223) days for glimepiride (p < 0.001) (IR = nadir HbA1c where change from baseline >= 0.5% or HbA1c < 6.5% within the first six months of treatment. After IR was detected, sustained response = time between nadir and an increase of > 0.3% above IR). Independent of disease duration, age was a predictor of effect sustainability. Fewer patients experienced hypoglycaemia with vildagliptin (2.3% vs. 18.2% with glimepiride) with a 14-fold difference in the number of hypoglycaemic events (59 vs. 838). Vildagliptin had a beneficial effect on body weight [mean (s.e.) change from baseline -0.3 (0.1) kg; between-group difference -1.5 kg; p < 0.001]. Overall, both treatments were well tolerated and displayed similar safety profiles. Conclusions: Vildagliptin add-on has similar efficacy to glimepiride after 2 years' treatment, with markedly reduced hypoglycaemia risk and no weight gain.