Primary Objective:

To assess the postprandial glucodynamic response to 2 doses of insulin glargine/lixisenatide fixed-ratio combination compared to placebo in Japanese patients with type 2 diabetes mellitus (T2DM).

Secondary Objectives:

• To assess the pharmacokinetics (PK) of lixisenatide following administration of 2 different doses of insulin glargine/lixisenatide fixed-ratio combination in Japanese patients with T2DM.
• To assess the postprandial glucodynamic response to insulin glargine/lixisenatide fixed-ratio combination compared to insulin glargine alone in Japanese patients with T2DM.
• To assess the safety and tolerability of insulin glargine/lixisenatide fixed-ratio combination in Japanese patients with T2DM.

The total study duration per patient will be approximately 6 to 13 weeks that will consist of a 2-28 days of screening period, a 3-day treatment period, a 7-14 days of washout period, and 1-day end of study visit.

Inclusion criteria :

• Japanese male or female patients with T2DM diagnosed for at least 1 year prior to the time of screening as established in the medical history.
• Patients aged 20 to 75 years at screening.
• Body mass index ≤35 kg/m^2 at screening.
• Glycohemoglobin ≥7.0% and ≤10.0% at screening.
• Fasting C-peptide ≥0.6 ng/mL at screening.

Exclusion criteria:

• Diabetes other than T2DM.
• History of metabolic acidosis, including diabetic ketoacidosis within 1 year prior to screening.
• History of hypoglycemia unawareness.
• Hemoglobinopathy or hemolytic anemia.
• History of myocardial infarction, stroke, or heart failure, history or presence of clinically significant diabetic retinopathy, history or presence of macular edema likely to require laser treatment within the study period.
• History of unexplained pancreatitis, chronic pancreatitis, pancreatectomy, stomach/gastric surgery, inflammatory bowel disease.
• Clinically relevant history of gastrointestinal disease associated with prolonged nausea and vomiting, including, but not limited to gastroparesis and gastroesophageal reflux disease requiring medical treatment.
• Personal or family history of medullary thyroid cancer (MTC) or genetic conditions that predispose to MTC (e.g., multiple endocrine neoplasia syndromes).
• If female, pregnancy or breast-feeding.

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