Efficacy and tolerability of initial combination therapy with vildagliptin and pioglitazone compared with component monotherapy in patients with type 2 diabetes

Aim: The aim of this study was to compare efficacy and tolerability of initial combination therapy with vildagliptin/pioglitazone to component monotherapy. Methods: This 24-week, multicentre, randomized, double-blind, active-controlled study assessed the effects of the dipeptidyl peptidase-4 inhibitor vildagliptin (100 mg q.d.), pioglitazone (30 mg q.d.) and vildagliptin combined with pioglitazone (100/30 mg q.d. or 50/15 mg q.d.) in 607 drug-naive patients with type 2 diabetes (T2DM). The primary outcome measure was change from baseline in HbA(1c) in patients receiving initial combination therapy compared with pioglitazone monotherapy. Results: After 24-week treatment, adjusted mean changes in HbA(1c) from baseline (approximately 8.7%) in patients receiving pioglitazone monotherapy, 50/15 mg combination, 100/30 mg combination and vildagliptin monotherapy were -1.4 +/- 0.1%, -1.7 +/- 0.1%, -1.9 +/- 0.1% and -1.1 +/- 0.1% respectively. Both low-dose and high-dose combinations were significantly more efficacious than pioglitazone alone (p = 0.039 and p < 0.001 respectively). Adjusted mean changes in fasting plasma glucose were -1.9 +/- 0.2, -2.4 +/- 0.2, -2.8 +/- 0.2 and -1.3 +/- 0.2 mmol/l respectively, and both combination groups were significantly more effective than pioglitazone monotherapy (p = 0.022 and p < 0.001 respectively). The overall incidence of adverse events ranged from 45.8% in the low-dose combination to 51.6% in the pioglitazone monotherapy group. The incidence of peripheral oedema was highest in patients receiving pioglitazone monotherapy (9.3%) and lowest in those receiving low-dose combination (3.5%). One mild hypoglycaemic event was reported by one patient receiving high-dose combination and one patient receiving vildagliptin monotherapy. Conclusions: First-line treatment with vildagliptin/pioglitazone combination in patients with T2DM provides better glycaemic control than either monotherapy component yet has minimal risk of hypoglycaemia and a tolerability profile comparable with component monotherapy.