RATIONALE: Monoclonal antibodies such as yttrium Y 90 ibritumomab tiuxetan and rituximab can locate cancer cells and either kill them or deliver radioactive cancer-killing substances to them without harming normal cells.

PURPOSE: Phase I trial to study the effectiveness of yttrium Y 90 ibritumomab tiuxetan in treating patients who have Waldenstrom's macroglobulinemia.

OBJECTIVES:

• Determine the maximum tolerated dose of yttrium Y 90 ibritumomab tiuxetan in patients with Waldenstrom's macroglobulinemia.
• Determine, preliminarily, the response of patients treated with this drug.

OUTLINE: This is a multicenter, dose-escalation study of yttrium Y 90 ibritumomab tiuxetan (IDEC-Y2B8).

Patients receive rituximab IV and indium In 111 ibritumomab tiuxetan (IDEC-In2B8) IV over 10 minutes on day 1. Patients then undergo gamma camera scans within 2-24 hours. Approximately 7-14 days after IDEC-In2B8, patients receive rituximab IV and IDEC-Y2B8 IV over 10 minutes. Treatment with IDEC-Y2B8 may repeat every 12 weeks in the absence of unacceptable toxicity or the achievement of a maximum cumulative dose.

Cohorts of 3-6 patients receive escalating doses of IDEC-Y2B8 until the maximum tolerated dose (MTD) is determined. The MTD is defined as the dose preceding that at which 2 of 6 patients experience dose-limiting toxicity.

Patients are followed every 3 months for 4 years.

PROJECTED ACCRUAL: A total of 3-24 patients will be accrued for this study.

Ages Eligible for Study:  18 Years and above,  Genders Eligible for Study:  Both

Criteria

DISEASE CHARACTERISTICS:

• Diagnosis of Waldenstrom's macroglobulinemia confirmed by IgM gammopathy and bone marrow biopsy
• Presence of lymphoplasmacytic cells
• CD20+ plasma cell dyscrasia on the majority of malignant cells
• Bone marrow involvement of 20-50% by core needle biopsy of at least 1.5 cm in length
• Clinical indication for initiation of treatment, including 1 or more of the following characteristics:
• Symptoms associated with the disease (e.g., fatigue, asthenia, or painful adenopathy)
• Anemia
• IgM greater than 3 g/L
• Progression as indicated by a rate of IgM rise of more than 0.5 g over 6 months
• No myelodysplastic syndromes or profound hypocellularity of the bone marrow

PATIENT CHARACTERISTICS: Age

• Over 18

Performance status

• WHO 0-2

Life expectancy

• More than 3 months

Hematopoietic

• Absolute neutrophil count greater than 1,500/mm^3
• Total B-lymphocyte count less than 5,000/mm^3
• Platelet count greater than 100,000/mm^3
• No hyperviscosity syndrome

Hepatic

• Bilirubin no greater than 1.5 mg/dL

Renal

• Not specified

Other

• Not pregnant or nursing
• Negative pregnancy test
• Fertile patients must use effective contraception during and for 1 year after study completion
• No uncontrolled CNS disease
• No serious nonmalignant disease that would preclude study participation
• No other concurrent active malignancy except controlled skin cancer or prostate cancer

PRIOR CONCURRENT THERAPY: Biologic therapy

• More than 2 weeks since prior filgrastim (G-CSF) or sargramostim (GM-CSF)
• More than 4 months since prior rituximab
• No prior radioimmunotherapy

Chemotherapy

• No prior high-dose chemotherapy (unless patient has had prior back-up stem cell collections)
• More than 6 weeks since prior chemotherapy

Endocrine therapy

• More than 4 weeks since prior corticosteroids

Radiotherapy

• No prior radiotherapy

Surgery

• Not specified