Inclusion Criteria:

- Adult patients >18 years of age

- CD20+ low-grade (indolent) lymphoma of follicular and marginal zone type, small
lymphocytic lymphoma without a B-CLL phenotype, or indolent lymphoma not otherwise
specified

- Stage II (with bulky disease), III, or IV lymphoma

- No previous chemotherapy or a maximum of 6 months chlorambucil or cyclophosphamide

- Indication for treatment: symptomatic enlarged lymph nodes, spleen or other lymphoma
manifestations, progression >6 months of lymphadenopathy or splenomegaly, anemia or
thrombocytopenia or decreased hemoglobin or platelets due to lymphoma, general
symptoms (weight loss, night sweats or fever)

- WHO performance status 0-2

Exclusion Criteria:

- Prior treatment with rituximab or an interferon

- B-CLL, mantle cell lymphoma, lymphoplasmacytic lymphoma (Waldenstroem's disease), or
central nervous system lymphoma

- Indolent lymphoma transformed into aggressive lymphoma

- Indolent lymphoma with bulky tumor requiring urgent therapy

- Prior malignancies, except non-melanoma skin tumors, in situ cervical cancer, or
curative surgery >5 years ago

- Positive for HIV infection

- Uncontrolled asthma or allergy requiring corticosteroids