Efficacy and Safety of the Insulin Glargine/Lixisenatide Fixed Ratio Combination Versus Insulin Glargine in Patients With Type 2 Diabetes

Inclusion criteria : * Type 2 diabetes mellitus diagnosed at least 1 year before the screening visit. * Treatment with basal insulin for at least 6 months before the screening visit. * Stable basal insulin regimen (i.e. type of insulin and time/frequency of the injection) for at least 3 months before the screening visit. * Stable (plus/minus 20 percent) total daily basal insulin dose between 15 and 40 Units/day for at least 2 months prior to the screening visit. * For participants receiving basal insulin and 1 or 2 oral anti-diabetic drugs (OADs): the OAD dose(s) must be stable during the 3 months before the screening visit. The OADs could be 1 to 2 out of: * metformin (more than or equal to 1500 mg/day or maximal tolerated dose), * a sulfonylurea, * a glinide, * a dipeptidyl-peptidase-4 inhibitor, * a sodium glucose co-transporter 2 inhibitor, * Fasting Plasma Glucose (FPG) less than or equal to 180 mg/dL(10.0 mmol/L) at screening visit for participants receiving basal insulin in combination with 2 OADs or with 1 OAD other than metformin; FPG less than or equal to 200 mg/dL (11.1 mmol/L) at screening visit for participants on basal insulin only or basal insulin plus metformin at screening visit. * Signed written informed consent. Exclusion criteria: * Age under legal age of adulthood at screening visit. * HbA1c at screening visit less than 7.5% or above 10%. * Pregnancy or lactation, women of childbearing potential with no effective contraceptive method. * Use of other oral or injectable glucose-lowering agents than stated in the inclusion criteria in a period of 3 months prior to screening. * Previous use of insulin other than basal insulin eg, prandial or pre-mixed insulin, in the year prior to screening. Note: Short term treatment (≤10 days) due to intercurrent illness is allowed. * History discontinuation of a previous treatment with Glucagon Like Peptide -1 Receptor Agonists for safety/tolerability or lack of efficacy. * Participant who had previously participated in any clinical trial with lixisenatide or the insulin glargine/lixisenatide FRC or had previously received lixisenatide. * Use of weight loss drugs within 3 months prior to screening visit. * Within the last 6 months prior to screening visit: history of stroke, myocardial infarction, unstable angina, or heart failure requiring hospitalization. Planned coronary, carotid or peripheral artery revascularisation procedures to be performed during the study period. * History of pancreatitis (unless pancreatitis was related to gallstones and cholecystectomy was already performed), chronic pancreatitis, pancreatitis during a previous treatment with incretin therapies, pancreatectomy, stomach/gastric surgery. * Personal or immediate family history of medullary thyroid cancer (MTC) or genetic conditions that predispose to MTC (eg, multiple endocrine neoplasia syndromes). * Uncontrolled or inadequately controlled hypertension (systolic blood pressure above 180 mmHg or diastolic blood pressure above 95 mmHg) at screening visit. * At screening visit, Body Mass Index (BMI) less than or equal to 20 or above 40 kg/m\^2. * At screening visit amylase and/or lipase more than 3 times the upper limit of the normal (ULN) laboratory range. * At screening visit alanine aminotransferase (ALT) or alkaline phosphatase (AST) more than 3 ULN. * At screening visit calcitonin above or equal to 20 pg/mL (5.9 pmol/L). * Any contraindication to metformin use, according to local labeling, if the participant was taking metformin. * Participant who had a renal function impairment with creatinine clearance less than 30 mL/min (using the Cockcroft and Gault formula) or end-stage renal disease for participants, not treated with metformin. Exclusion criteria for randomization: * HbA1c less than 7% or above 10% . * Mean fasting SMPG calculated from the self-measurements for 7 days the week before randomization visit was above 140 mg/dL (7.8 mmol/L). * Average insulin glargine daily dose less than 20 Units or above 50 Units (in the week before randomization visit). * Amylase and/or lipase more than 3 ULN . The above information is not intended to contain all considerations relevant to a participant's potential participation in a clinical trial.