Drug-nave , recently diagnosed subjects with type 2 diabetes mellitus ( T2DM ) were randomized in an open-fashion design in a single-centre study to metformin/pioglitazone/exenatide ( triple therapy ; n = 106 ) or an escalating dose of metformin followed by sequential addition of sulfonylurea and glargine insulin ( conventional therapy ; n = 115 ) to maintain HbA1c levels at < 6.5 % for 2years .