Primary objective:

To compare long-term glycemic control and preservation of beta cell function when basal insulin or sulfonylurea is added on metformin in the early Type 2 Diabetes Mellitus patients

Secondary objective:

To assess the change of insulin resistance, microvascular complication incidence, patient satisfaction with treatment

List of Inclusion and Exclusion Criteria:

Inclusion Criteria:

• Type 2 Diabetes Mellitus patients on metformin monotherapy
• 7% ≤ HbA1c ≤ 12%
• 20 kg/m² ≤BMI ≤ 35 kg/m²
• Diabetes duration: at least 6 months

Exclusion Criteria:

• Type 1 Diabetes Mellitus patients
• Clinical evidence of active liver disease, or serum Alanine AminoTransferase 3 times the upper limit of the normal range
• Serum creatinine: 1.5 mg/dl for males, 1.4 mg/dl for females
• Acute and chronic metabolic acidosis, including diabetic ketoacidosis
• History of alcohol or other substance abuse
• Pregnancy or not using contraceptive in childbearing aged women
• Known hypersensitivity to Lantus, SU or metformin
• Any disease or condition that in the opinion of the investigator may interfere with completion of the study

The above information is not intended to contain all considerations relevant to a patient's potential participation in a clinical trial.