Inclusion Criteria

DISEASE CHARACTERISTICS: Diagnosis of B-cell chronic lymphocytic leukemia manifested by
all of the following: Minimum threshold peripheral lymphocyte count of at least 5,000/mm3
Small to medium sized peripheral blood lymphocytes with no greater than 55% prolymphocytes
Bone marrow aspirate and biopsy containing at least 30% lymphoid cells Immunophenotypic
and biopsy evaluation of peripheral blood lymphocytes demonstrating monoclonality of B
lymphocytes B-cell markers with CD5 antigen (e.g., T-1, T-101) in the absence of other pan
T-cell markers (e.g., CD3, CD2) Expression of CD19, CD20, and CD23 B cell surface markers
B-cell expression of kappa or lambda light chains Active disease with at least one of the
following criteria: One or more disease related symptoms: At least 10% weight loss within
the past 6 months Fever greater than 100.5 F for at least 2 weeks without evidence of
infection Night sweats without evidence of infection Evidence of progressive marrow
failure as manifested by the development of or worsening of anemia (hemoglobin less than
11.0 g/dL) and/or thrombocytopenia (platelet count less than 100,000/mm3) (i.e., any stage
III or IV disease) Autoimmune anemia and/or thrombocytopenia poorly responsive to
corticosteroid therapy Massive (i.e., greater than 6 cm below the left costal margin) or
progressive splenomegaly (i.e., a greater than 50% increase over two months) Massive
(i.e., greater than 10 cm in longest diameter) or progressive lymphadenopathy (i.e., a
greater than 50% increase over two months) Progressive lymphocytosis with an increase of
greater than 50% over a 2 month period (unrelated to corticosteroids) or an anticipated
doubling time of less than 6 months No marked hypogammaglobulinemia or the development of
a monoclonal protein in the absence of any criteria for active disease Previously treated
with at least a fludarabine or cladribine based regimen and a prior alkylating agent with
evidence of recurrent or progressive disease

PATIENT CHARACTERISTICS: Age: 18 and over Performance status: ECOG 0-2 Life expectancy:
Not specified Hematopoietic: See Disease Characteristics Platelet count at least
75,000/mm3 Hepatic: Bilirubin no greater than 1.5 times upper limit of normal (ULN) SGOT
no greater than 1.5 times ULN (unless due to hemolysis or chronic lymphocytic leukemia)
Renal: Creatinine no greater than 1.5 times ULN Cardiovascular: No New York Heart
Association class III or IV heart disease No myocardial infarction within the past month
Other: No uncontrolled infection HIV negative No other active malignancy Not pregnant or
nursing Negative pregnancy test Fertile patients must use effective contraception

PRIOR CONCURRENT THERAPY: Biologic therapy: Not specified Chemotherapy: See Disease
Characteristics At least 4 weeks since prior chemotherapy Endocrine therapy: See Disease
Characteristics No concurrent corticosteroids Radiotherapy: At least 4 weeks since prior
radiotherapy Surgery: At least 4 weeks since prior major surgery