Inclusion Criteria:

1. Age ≥ 18 and ≤ 75 years.

2. Patients with follicular lymphoma grade 1, 2 or 3a, CD20 +, histologically confirmed
lymph node biopsy or tissue. Be accepted diagnosis in bone marrow if no accessible
lymph nodes and whether it has discarded the mantle LLC, and NHL.

3. Follicular lymphoma patients treated with the combination of rituximab and
chemotherapy in first line, which have been refractory or relapsed after having
achieved any responses to this first line of pretreatment (excluding radiotherapy).

4. ECOG ≤ 2.

5. Signed written informed consent.

Exclusion Criteria:

1. Clinical suspicion or documentation of histological transformation.

2. Have received prior chemotherapy scheme, first line without Rituximab.

3. Prior autologous or allogeneic.

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 serious immunosuppression.

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

8. Cardiac function in cardiac patient known or prior treatment with anthracyclines with
EF <50%.

9. Impaired renal function (creatinine> 1.5 x Upper Limit of Normal, LSN) or a
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. Women of childbearing potential will be included
prior pregnancy test serum / urine negative. Use effective contraception to be kept
for 1 year after cessation of rituximab.

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.