Inclusion Criteria:

1. Age ≥ 18 years.

2. Patients with follicular lymphoma grade 1, 2 or 3a, CD20 +, histologically confirmed
lymph node biopsy or tissue.

3. Follicular lymphoma patients previously treated with the combination of rituximab and
chemotherapy (R-CHOP, R-CVP, R-fludarabine), having received rituximab maintenance,
refractory to a first line (excluding radiotherapy) or relapsed after having achieved
any response to previous treatment.

4. ECOG ≤ 2.

5. Signed written informed consent

Exclusion Criteria:

1. Clinical suspicion or documentation of histological transformation.

2. Patients with hypersensitivity to rituximab.

3. Prior autologous or allogeneic transplant.

4. CNS infiltration by LF (primary CNS lymphoma or lymphomatous meningitis).

5. Past or active Hepatitis B (at least one of the following markers HBsAg, HBe Ag,
anti-HBc, HBV DNA).

6. HCV infection. HIV infection or other conditions of severe immunosuppression.

7. Previous neoplasms except non-melanoma skin cancer of the cervix or adequately
treated.

8. Congestive heart failure> NYHA grade 1.

9. Impaired renal function (creatinine> 1.5 x Upper Limit of Normal, ULN) or creatinine
clearance <50 ml / h, not related to lymphoma.

10. Impaired liver function (bilirubin, AST / ALT or GGT> 2 x ULN) were not related to
lymphoma.

11. Women who are nursing or pregnant.

12. Patients with heart disease, pulmonary, neurological, psychiatric or severe metabolic
and not secondary to lymphoma.

13. Severe acute or chronic infection in activity.

14. Any other concurrent medical or psychological comorbidity that might interfere with
participation in this study.