Subjects were randomized to a combination of empagliflozin 25 mg/linagliptin 5 mg ( n = 137 ) , empagliflozin 10 mg/linagliptin 5 mg ( n = 136 ) , empagliflozin 25 mg ( n = 141 ) , empagliflozin 10 mg ( n = 140 ) , or linagliptin 5 mg ( n = 132 ) as add-on to metformin for 52 weeks .