RATIONALE: Monoclonal antibodies such as rituximab can locate cancer cells and either kill them or deliver cancer-killing substances to them without harming normal cells. Drugs used in chemotherapy use different way to stop cancer cells from dividing so they stop growing or die. Combining monoclonal antibody therapy with chemotherapy may kill more cancer cells.

PURPOSE: Phase II trial to study the effectiveness of rituximab plus fludarabine in treating patients who have Waldenstrom's macroglobulinemia.

OBJECTIVES:

• Determine the objective response and time to treatment failure in patients with Waldenstrom's macroglobulinemia treated with rituximab and fludarabine.
• Determine the toxicity of this regimen in these patients.
• Determine if molecular remissions are achievable in patients attaining a clinical complete response when treated with this regimen.

OUTLINE: This is a multicenter study.

Patients receive rituximab IV over 3-6 hours once weekly on weeks 1-4, 17, 18, 30, and 31 and fludarabine IV over 10-30 minutes once daily for 5 days on weeks 5, 9, 13, 19, 23, and 27.

Patients are followed at least every 2 months for 2 years.

PROJECTED ACCRUAL: A total of 40 patients will be accrued for this study.

• Biological: rituximab
• Drug: fludarabine phosphate

DISEASE CHARACTERISTICS:

• Diagnosis of Waldenstrom's macroglobulinemia
• CD20 positive by bone marrow immunohistochemistry or flow cytometry
• Presence of monoclonal paraprotein
• IgM level at least 2 times upper limit of normal (ULN)

PATIENT CHARACTERISTICS:

Age:

• Over 18

Performance status:

• ECOG 0-2

Life expectancy:

• At least 6 months

Hematopoietic:

• Absolute neutrophil count greater than 1,000/mm^3
• Platelet count greater than 25,000/mm^3

Hepatic:

• Bilirubin less than 2.5 times ULN
• SGOT less than 2.5 times ULN

Renal:

• Creatinine less than 2.5 mg/dL

Other:

• Not pregnant or nursing
• Fertile patients must use effective contraception during and for 6 months after study
• No serious comorbid disease
• No uncontrolled bacterial, fungal, or viral infection
• No other active malignancy

PRIOR CONCURRENT THERAPY:

Biologic therapy:

• No prior rituximab
• No prior nucleoside analogue therapy

Chemotherapy:

• At least 30 days since prior chemotherapy

Endocrine therapy:

• At least 30 days since prior steroid therapy
• No concurrent corticosteroids

Radiotherapy:

• At least 30 days since prior radiotherapy

Surgery:

• Not specified

Other:

• No more than 2 prior courses of therapy