Inclusion Criteria

DISEASE CHARACTERISTICS:

- Diagnosis of Waldenstrom's macroglobulinemia (lymphoplasmacytic lymphoma)

- Immunoglobulin (Ig) M, IgG, and IgA paraprotein

- Measurable monoclonal paraprotein

- Failed at least 1 prior first-line therapy (alkylator agent, nucleoside analogue, or
rituximab)

- CD52-positive tumor determined by either bone marrow immunohistochemistry or flow
cytometry

PATIENT CHARACTERISTICS:

Age

- Over 18

Performance status

- ECOG 0-2

Life expectancy

- At least 6 months

Hematopoietic

- Absolute neutrophil count ≥ 500/mm^3

- Platelet count ≥ 25,000/mm^3

Hepatic

- SGOT ≤ 2.5 times upper limit of normal (ULN)

- Bilirubin ≤ 2.5 times ULN

Renal

- Creatinine ≤ 2.5 mg/dL (> 2.5 mg/dL allowed if due to disease)

Other

- Not pregnant or nursing

- Negative pregnancy test

- Fertile patients must use effective double-method contraception during and for 6
months after study participation

- No serious comorbid disease

- No uncontrolled bacterial, fungal, or viral infection

- No other active malignancy

PRIOR CONCURRENT THERAPY:

Biologic therapy

- See Disease Characteristics

- No prior alemtuzumab

- More than 3 months since other prior monoclonal antibody therapy

Chemotherapy

- See Disease Characteristics

- More than 21 days since prior chemotherapy

Endocrine therapy

- More than 21 days since prior steroid therapy

Radiotherapy

- More than 21 days since prior radiotherapy

Surgery

- Not specified