Safety and Efficacy of BI 10773 as add-on to Insulin Regimen in Patients With Type 2 Diabetes Mellitus

Inclusion criteria:

1. Diagnosis of T2DM prior to informed consent

2. Male and female patients on diet and exercise regimen who are pre-treated withmultiple daily injections (MDI) of insulin alone or in combination with immediate orextended release metformin

3. Stable metformin therapy: daily dose >=1500 mg/day or maximum tolerated dose

4. HbA1c >=7.5% and <=10% at screening

Exclusion criteria:

1. Uncontrolled hyperglycemia with a glucose level >240 mg/dl (>13.3 mmol/L) after anovernight fast during placebo run-in

2. Any contraindications to metformin according to the local label

3. Acute coronary syndrome, stroke or TIA within 3 months prior to informed consent