Inclusion Criteria:

- Diagnosis of B-cell non Hodgkin's lymphoma

- Relapsed or refractory after standard treatments and with no curative option with
conventional therapy (Patients having undergone stem cell transplantation may be
included)

- CD19 positive disease by flow cytometry or immunohistochemistry

Exclusion Criteria:

- Burkitt's lymphoma, Lymphoblastic lymphoma, Chronic lymphocytic leukemia (Small
lymphocytic lymphoma may be included)

- Evidence of cerebral or meningeal involvement by lymphoma

- Patients without bi-dimensionally measurable disease

- ECOG performance status > 2

- Life expectancy less than 3 months

- Chemotherapy or radiation therapy or other investigational agents within 4 weeks
prior to entering the study

- Previous radioimmunotherapy within 12 weeks

- Known anaphylaxis to infused proteins

- HIV, HBV and HCV positivity

- 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 the compliance with the
study

- Pregnant or breast-feeding women

- Patients 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.