Study of Inotuzumab Ozogamicin Combined to Chemotherapy in Older Patients With Philadelphia Chromosome-negative CD22+ B-cell Precursor ALL

Inclusion Criteria: * Patients aged more than 55 years old, * With confirmed diagnosis of BCP-ALL according to World Health Organisation (WHO) criteria expressing the CD22 antigen by flow cytometry (20% or more positive blast cells), * Without central nervous system (CNS) involvement, * Without BCR-ABL fusion by standard cytogenetics, Fluorescence In Situ Hybridization (FISH) analysis and/or RT-PCR, * Previously untreated, * Eligible to intensive chemotherapy, due to general health status, * ECOG performance status ≤ 2, * Patients must have the following laboratory values unless considered due to leukemia: AST and ALT ≤ 2.5 x upper the limit of normal (ULN); estimated GFR ≥ 50 mL/min using the MDRD equation; total and direct serum bilirubin ≤ 1.5 x ULN; electrolyte panel within normal ranges for the institution unless attributed to the underlying disease. * Written informed consent obtained prior to any screening procedures. * Eligible for National Health Insurance in France. Exclusion Criteria: * Concurrent therapy with any other investigational agent or cytotoxic drug, * Prior documented chronic liver disease, * Active Hepatitis B Virus (HBV) or Hepatitis C Virus (HCV) or positive HIV serology, * Female patients who are pregnant or breast feeding or patients of childbearing potential not willing to use a double barrier method of contraception during the study and for 3 months following the last dose of maintenance. * Male patients whose sexual partner(s) are women of childbearing potential who are not willing to use a double barrier method of contraception, one of which includes a condom, during the study and for 3 months following the last dose of maintenance. * Any of concurrent severe and/or uncontrolled medical condition, which could compromise participation in the study.