24-week Treatment With Lixisenatide in Type 2 Diabetes Insufficiently Controlled With Metformin and Insulin Glargine

The study comprises 3 periods: * An up to 14-week screening period, which includes an up to 2-week screening phase and a 12-week run-in phase with introduction and titration of insulin glargine on top of metformin +/-TZDs. * At the end of the run-in phase, patients whose HbA1c (centralized assay) is greater than or equal to (\>=) 7% and less than or equal to (\<=) 9% and whose mean fasting self-monitored plasma glucose (SMPG) calculated from the self measurements for the 7 days prior to Visit 12 (Week -1) is \<=140 milligram per deciliter (mg/dL) (7.8 millimole per liter \[mmol/L\]), would enter a 24-week double-blind randomized treatment period comparing lixisenatide to placebo (on top of insulin glargine + metformin +/- TZDs). * A 3-day safety follow up period. Maximum duration is of 39 weeks +/- 7 days.