Approximately 2000 people with Type 2 diabetes mellitus who were drug-naive or who were treated with metformin for less than 1 month , and who have HbA1c of 48-58 mmol/mol ( 6.5-7 .5 % ) , will be randomized in a 1:1 ratio in VERIFY , a 5-year multinational , double-blind , parallel-group study designed to compare early initiation of a vildagliptin-metformin combination with standard-of-care initiation of metformin monotherapy , followed by the stepwise addition of vildagliptin when glycaemia deteriorates .