Inclusion Criteria:

- Histologically confirmed:

- Follicular lymphoma grade 1, 2, 3a

- Marginal zone lymphoma, including MALT type

- Small lymphocytic lymphoma (BM inv. < 30%)

- Lymphoplasmacytic lymphoma

- Clinical stage II-IV (Ann Arbor). Stage I is allowed if bulky (Ø > 7 cm) or if
radiotherapy is not appropriate in judgment of treating physician

- Measurable lesion(s) in at least one site

- Patients previously untreated

- Patients presenting with symptoms requiring treatment:

- Progressive disease

- Symptoms related to tumor bulk

- Cytopenias related to bone marrow and/or spleen involvement B symptoms

- Age ≥ 18 years

- Performance status
- Written informed consent

Exclusion Criteria:

- Grade 3b FL

- Transformed lymphoma

- CNS involvement

- Patient taking steroids for > 2 weeks during last 4 weeks at a dose equivalent to ≥
20 mg prednisone

- Other malignancy

- Major surgery within 4 weeks

- Hb < 8 g/dl, ANC < 1.5 x 109/L, Plt <100 109/L unless due to lymphoma

- Impairment of renal function (creatinine > 1.5 x UNV) or liver function (total
bilirubin 1.5 x UNV, SGOT > 2.5 x UNV not due to lymphoma

- Known infection, with HBV, HCV (acute < 6 mos. or chronic hepatitis) or HIV

- Serious underlying medical conditions

- Life expectancy < 6 months

- Known allergy to murine protein