Primary Objective:

To compare the efficacy of a new formulation of insulin glargine and Lantus in terms of change of HbA1c from baseline to endpoint (scheduled at month 6 [week 26]) in japanese patients with type 2 diabetes mellitus.

Secondary Objectives:

To compare a new formulation of insulin glargine and Lantus in terms of change in fasting plasma glucose (FPG), preinjection plasma glucose, 8-point self-measured plasma glucose (SMPG) profile.

To compare a new formulation of insulin glargine and Lantus in terms of occurrence of hypoglycemia

The duration of study will consist of:

• Up to 2-week screening period;
• 6-month open-label comparative efficacy and safety treatment period;
• 6-month open-label comparative safety extension period;
• 4-week post-treatment safety follow-up period

Inclusion criteria :

o Patients with type 2 diabetes mellitus diagnosed for at least 1 year at the time of screening visit treated with basal insulin in combination with oral antihyperglycemic drugs (OADs) for at least 6 months before screening visit;

Exclusion criteria:

• Age < 18 years at screening visit;
• BMI(body mass index) ≥ 35 kg/m2 at screening visit;
• HbA1c < 7.0% or > 10% (national glycohemoglobin standardization program [NGSP] value) at screening visit;
• Diabetes other than type 2 diabetes mellitus;
• Patients on self-monitoring of blood glucose less than 6 months before screening visit;
• Patients using pre-mix insulins, insulin detemir at 2 times or more a day, or GLP 1 receptor agonists in the last 3 months before screening visit;
• Patients using mealtime insulin (rapid-acting insulin analogue and short-acting insulin) for more than 10 days in the last 3 months before screening visit;
• Use of insulin pump in the last 6 months before screening visit;
• Initiation of new glucose-lowering medications and/or weight loss drugs in the last 3 months before screening visit;
• Severe hypoglycemia resulting in coma/seizures, and/or hospitalization for diabetic ketoacidosis in the last 6 months before screening visit;
• Unstable proliferative diabetic retinopathy or any other rapidly progressive diabetic retinopathy or macular edema likely to require treatment (eg, laser, surgical treatment or injectable drugs) during the study period.

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