Linagliptin 2.5 mg Twice Daily Versus 5 mg Once Daily as add-on Therapy to Twice Daily Metformin in Type 2 Diabetes

12 Week Randomised Double-blind BI 1356 2.5 mg Bid vs 5 mg qd add-on to Metformin

The objective of the study is to investigate the efficacy and safety of linagliptin 2.5 mg twice daily compared to 5 mg once daily compared to placebo given orally for 12 weeks as add-on therapy to metformin in patients with type 2 diabetes mellitus with insufficient glycaemic control. It is planned to show non-inferiority of linagliptin 2.5 mg twice daily compared to 5 mg once daily and each treatment's superiority over placebo.

Inclusion criteria

1. Diagnosis of type 2 diabetes mellitus.
2. Current treatment with metformin alone (>/= 1500 mg or maximally tolerated dose) or metformin plus 1 other antidiabetic drug. Metformin must be administered in twice daily dosing regimen. Patients taking metformin three times daily can be included if posology is switched to twice daily and total daily dose is maintained.
3. Glycosylated haemoglobin (HbA1c) is between 7.0% - 10.0%.
4. Body Mass Index (BMI) </=45 kg/m2.

Exclusion criteria

1. Treatment with extended release metformin.
2. Uncontrolled hyperglycaemia (fasting plasma glucose > 240 mg/dL or 13.3 mmol/L).
3. Myocardial infarction (MI), stroke or transient ischaemic attack (TIA) within 6 months prior to informed consent.
4. Impaired hepatic or renal function, or gastric bypass surgery.
5. Treatment with glitazones, glucagon like peptide-1 (GLP-1) analogues/mimetics, antiobesity agents, or insulin within 3 months of informed consent.
6. Current treatment with systemic steroids or change in dosage of thyroid hormones.
7. Alcohol or drug abuse within 3 months of informed consent.
8. Participation in another trial with investigational drug within 2 months prior to informed consent.
9. Pre-menopausal women who are nursing, pregnant or not practicing an acceptable method of birth control.