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

The purpose of the study is to evaluate the benefits and risks of lixisenatide (AVE0010), in comparison to placebo, as an add-on treatment to insulin glargine and metformin with or without thiazolidinediones (TZDs), over a period of 24 weeks of treatment. The primary objective is to assess the effects of lixisenatide in comparison to placebo, when added to insulin glargine and metformin, on glycemic control in terms of glycosylated hemoglobin (HbA1c) reduction (absolute change) at Week 24. The secondary objectives are to assess the effects of lixisenatide on the percentage of patients reaching HbA1c less than (\<) 7 percent (%) and less than or equal to (\<=) 6.5%, plasma glucose (fasting, postprandial during a standardized meal challenge test, 7-point self monitored profiles), body weight, insulin glargine doses, to evaluate safety and tolerability (including anti-lixisenatide antibody assessment), and to assess the impact on treatment satisfaction using the Diabetes Treatment Satisfaction Questionnaire (state) (DTSQs) in the participating countries where it is validated.

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.