Approximately @ people with Type @ diabetes mellitus who were drug-naive or who were treated with metformin for less than @ month , and who have HbA@c of @-@ mmol/mol ( @-@ @ % ) , will be randomized in a @:@ ratio in VERIFY , a @-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 .