Multiple Ascending Dose Study in Healthy Male Subjects and Overweight to Obese Male and Female Type 2 Diabetes Mellitus (T2DM) Patients

Primary Objective: To assess in healthy adult male subjects: * The tolerability and safety of 21-day repeated subcutaneous (SC) doses of SAR425899 including two up titration steps. * Pharmacokinetic (PK) parameters of SAR425899 after ascending repeated SC doses in plasma. * Pharmacodynamic (PD) effects on fasting and postprandial plasma glucose, insulin, biomarkers of lipid metabolism and fibroblast growth factor 21 (FGF21). To assess in overweight to obese T2DM mellitus patients: * The tolerability and safety after 28-day repeated SC doses of SAR425899 including 2 up titration steps. * PK parameters of SAR425899 after ascending repeated SC doses in plasma and urine. * PD effects on fasting and postprandial plasma glucose, insulin, C-peptide, incretin panel (total and active ghrelin, total peptide YY \[PYY\], total and active glucagon-like peptide -1 \[GLP-1\], glucagon and total gastric inhibitory polypeptide-1 \[GIP\]), body weight, FGF21, biomarkers of lipid metabolism and HbA1c.