Inclusion Criteria:

1. male or female patients ≥ 18 years of age.

2. histologically-confirmed diagnosis according to REAL/WHO classification, of the
following B-cell lymphomas :

1. FL

2. MCL

3. DLBCL

4. Other indolent NHL (eg, MZL/MALT)

3. Patients' NHL must have progressed after at least 1 prior rituximab containing
regimen.

4. one site of measurable disease by magnetic resonance imaging (MRI) or computed
tomography (CT) scan defined as at least one lesion that measures at least 1.5 × 1.5
cm,

Exception:

For patients with MCL only, patients with nonmeasurable disease but evaluable sites
(bone marrow, spleen, peripheral blood, gastrointestinal tract) can be enrolled.

5. Patients who have previously received an autologous stem cell transplantation must be
at least 4 weeks post-transplant before study drug administration and must have
exhibited a full haematological recovery

6. discontinued previous monoclonal antibody therapy (except rituximab) or
radioimmunotherapy administration for at least 60 days before study drug
administration.

7. off rituximab for at least 14 days before the screening visit and be confirmed to
have either no response or have disease progression after rituximab treatment.

8. Patients with DLBCL had a positive [18F]fluorodeoxyglucose-positron emission
tomography (FDG-PET) scan at baseline (Cheson response criteria)

9. Life expectancy of > 3 months.

10. ECOG performance status of < 3.

11. laboratory criteria at screening:

1. Absolute neutrophil count (ANC) ≥ 1.0 (1000/mm3)

2. Platelet count ≥ 75 × 109/L without previous transfusion within 10 days of first
study drug administration

3. Haemoglobin ≥ 8.0 g/dL (may have been transfused)

4. Serum creatinine < 2.0 x upper limit of normal (ULN)

5. Total bilirubin ≤ 2.0 × ULN

6. Alanine transaminase (ALT) and aspartate aminotransferase (AST) ≤ 2.5 × ULN.

12. If a female of childbearing potential, a negative pregnancy test must be confirmed
before enrolment and use of double-barrier contraception, oral contraceptive plus
barrier contraceptive, or confirmation of having undergone clinically documented
total hysterectomy and/or oophorectomy, tubal ligation.

13. If a male, an effective barrier method of contraception must be used during the study
and for 3 months after the last dose if the patient is sexually active with a female
of childbearing potential.

14. able to comply with all study-related procedures, medication use, and evaluations.

15. able understand and give written informed consent and comply with the study protocol.

Exclusion Criteria:

1. Previous treatment with cytotoxic chemotherapy, immunotherapy, radiotherapy or other
lymphoma specific therapy within 14 days before the screening visit or patient has
not recovered from side effects of previous lymphoma-specific therapy.

2. Treatment with a systemic investigational agent within 28 days before the screening
visit.

3. Previous treatment with an anti-CD19 antibody or fragments

4. Previous allogenic stem cell transplantation.

5. Known or suspected hypersensitivity to the excipients contained in the study drug
formulation.

6. Clinically significant cardiovascular disease or cardiac
insufficiency,cardiomyopathy, preexisting clinically significant arrhythmia, acute
myocardial infarction within 3 months of enrolment, angina pectoris within 3 months
of enrolment.

7. Clinical or laboratory evidence of active hepatitis B or hepatitis C 8. History of
HIV infection.

9. Any active systemic infection (viral, fungal, or bacterial) requiring active parenteral
antibiotic therapy within 4 weeks of study drug administration.

10. Current treatment with immunosuppressive agents other than prescribed corticosteroids
(not more than 10-mg prednisone equivalent).

11. Major surgery or radiation therapy within 4 weeks before first study drug
administration.

12. Systemic diseases (cardiovascular, renal, hepatic, etc) that would prevent study
treatment in the investigator's opinion.

13. History or clinical evidence of central nervous system (CNS), meningeal, or epidural
disease, including brain metastasis.

14. Active treatment/chemotherapy for another primary malignancy within the past 5 years
15. Pregnancy or breastfeeding in women and women of childbearing potential not using an
acceptable method of birth control.

16. History of noncompliance to medical regimens or patients who are considered
potentially unreliable not cooperative