Combination Chemotherapy and Rituximab in Treating Patients With Chronic Lymphocytic Leukemia or Lymphocytic Lymphoma

DISEASE CHARACTERISTICS:

Diagnosis of B-cell chronic lymphocytic leukemia (CLL) or small B-cell lymphocytic lymphoma (SLL) with the following:

Lymph node biopsy interpreted as SLL or consistent with CLL or all of the following:

Peripheral lymphocyte count greater than 5,000/mm^3 with small to moderate peripheral lymphocytes and no more than 55% prolymphocytes
Bone marrow aspirate containing at least 30% lymphoid cells

Immunophenotypic evaluation of peripheral blood lymphocytes demonstrating monoclonality of B lymphocytes with all of the following:

CD19 or CD20 coexpressed with CD5 antigen in the absence of other pan-T- cell markers (e.g., CD2 or CD3)
Expression of CD23 on CLL cells or Dim B-cell expression of kappa or lambda light chains

Measurable disease with any of the following:

1 or more lymph nodes at least 1.5 cm by CT scan
Splenomegaly by CT scan
Peripheral lymphocyte count greater than 5,000/mm3 with coexpression of CD5 and B-cell markers
Bone marrow aspirate with at least 30% lymphoid cells
No mantle cell lymphoma

PATIENT CHARACTERISTICS:

Age

18 and over

Performance status

ECOG 0-2

Life expectancy

At least 2 years

Hematopoietic

See Disease Characteristics
No immune thrombocytopenia
No hemolytic anemia

Hepatic

Bilirubin no greater than 3 times upper limit of normal (ULN)
SGOT no greater than 3 times ULN (unless due to hemolysis or CLL)
No hepatitis

Renal

Creatinine no greater than 1.5 times ULN

Cardiovascular

No cardiac dysfunction
No New York Heart Association class III or IV heart disease
No myocardial infarction within the past month

Other

HIV negative
No active acute or chronic infection
No immunosuppressive diseases
No autoimmune disorder
No secondary malignancy that is projected to limit life expectancy
Not pregnant or nursing
Negative pregnancy test
Fertile patients must use effective contraception

PRIOR CONCURRENT THERAPY:

Biologic therapy

See Chemotherapy
No prior rituximab
At least 4 weeks since prior biologic therapy

Chemotherapy

At least 4 weeks since prior chemotherapy
No prior combination chemotherapy and rituximab or other antibody therapy
No prior combination chemotherapy comprising an alkylating agent and a purine nucleoside analog (i.e., cyclophosphamide or chlorambucil in combination with fludarabine, cladribine, or pentostatin)
No prior pentostatin

Endocrine therapy

At least 4 weeks since prior corticosteroids
No concurrent supra-physiologic doses of corticosteroids

Radiotherapy

At least 4 weeks since prior radiotherapy

Surgery

At least 4 weeks since prior major surgery

Other

No concurrent immunosuppressive therapy (e.g., cyclosporine)