The primary objective is to determine the maximum tolerated dose of SAR3419 and to characterize the dose limiting toxicity(ies). Secondary objectives are to determine the anti-lymphoma activity, the global safety and the PK profile.

Inclusion Criteria:

• Histologically confirmed CD19-positive non-Hodgkin's B-cell lymphoma, relapsed or refractory after standard treatments, with no curative option with conventional therapy
• ECOG performance status 0 to 2

Exclusion Criteria:

• Burkitt's lymphoma, Lymphoblastic lymphoma, Chronic lymphocytic leukemia (Small lymphocytic lymphoma may be included)
• Chemotherapy or radiation therapy or other investigational agents within 4 weeks prior to entering the study
• Previous radioimmunotherapy within 12 weeks
• Known intolerance to infused protein products or maytansinoids
• Poor kidney, liver and bone marrow functions
• Any serious active disease or co-morbid condition, which in the opinion of the principle investigator, will interfere with the safety or with compliance with the study
• Pregnant or breast-feeding women
• Patient with reproductive potential without effective birth control methods

The above information is not intended to contain all considerations relevant to a patient's potential participation in a clinical trial.