Patients with HbA1c levels of 7 % to 10 % ( 53 to 86 mmol/mol ) while receiving metformin ( 1,500 mg/day ) were randomized and treated with once-daily treatment with empagliflozin 10 mg ( n = 217 ) , empagliflozin 25 mg ( n = 213 ) , or placebo ( n = 207 ) for 24 weeks .