Rituximab, Pentostatin, Cyclophosphamide, and Lenalidomide in Treating Patients With Previously Untreated B-Cell Chronic Lymphocytic Leukemia or Small Lymphocytic Lymphoma

DISEASE CHARACTERISTICS:

Diagnosis of chronic lymphocytic leukemia (CLL) or small lymphocytic lymphoma (SLL), meeting the following criteria:

Biopsy-proven SLL according to WHO criteria

CLL diagnosis* according to NCI working group criteria as evidenced by all of the following:

Peripheral blood lymphocyte count of > 5,000/mm³
Small to moderate peripheral blood lymphocyte with < 55% prolymphocytes

Immunophenotyping consistent with CLL defined as:

B-cell markers with CD5 antigen in the absence of other pan-T-cell markers (e.g., CD3, CD2)
CD19, CD20, or CD23
Dim surface immunoglobulin expression
Exclusively kappa or lambda light chains
Diagnosis of mantle cell lymphoma must be excluded by negative FISH analysis for t(11;14)(IgH/CCND1) on peripheral blood or tissue biopsy or negative immunohistochemical stains for cyclin D1 on involved tissue biopsy NOTE: *Splenomegaly, hepatomegaly, or lymphadenopathy are not required for the diagnosis of CLL

Previously untreated disease and meets ≥ 1 of the following criteria*:

At least 1 or more of the following disease-related symptoms:

Weight loss > 10% within the previous 6 months
Extreme fatigue attributed to CLL
Fevers > 100.5º F for 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 anemia (i.e., hemoglobin ≤ 11 g/dL) and/or thrombocytopenia (i.e., platelet count ≤ 100,000/mm³) not due to autoimmune disease
Symptomatic or progressive lymphadenopathy, splenomegaly, or hepatomegaly
Progressive lymphocytosis due to CLL with an increase of > 50% over a 2-month period or an anticipated doubling time < 6 months NOTE: *Marked hypogammaglobulinemia or the development of a monoclonal protein in the absence of any of the above criteria for active disease are not sufficient for protocol therapy

PATIENT CHARACTERISTICS:

ECOG performance status 0-3
Serum creatinine ≤ 1.5 times upper limit of normal (ULN)

Total bilirubin ≤ 3.0 times ULN (unless due to Gilbert disease)

Direct bilirubin < 1.5 mg/dL for Gilbert disease to be diagnosed if total bilirubin > 3.0 times ULN
AST and ALT ≤ 3.0 times ULN (unless due to hemolysis or CLL)
Willing to provide blood samples
Able to take acetylsalicylic acid (ASA) (81 or 325 mg) daily as prophylactic anticoagulation (patients intolerant to ASA may use low molecular weight heparin)
Not pregnant or nursing
Negative pregnancy test
Female patients must use effective double-method contraception beginning 1 month prior to, during, and for 4 weeks after completion of study treatment
Male patients must use effective contraception during and for 4 weeks after completion of study treatment

No comorbid conditions, including any of the following:

New York Heart Association class III or IV heart disease
Recent myocardial infarction (< 1 month)
Uncontrolled infection
Infection with HIV/AIDS
No other active primary malignancy requiring treatment or that limits survival to ≤ 2 years
No history of deep venous thrombosis or pulmonary embolism ≤ 12 months prior to study registration
No active hemolytic anemia requiring immunosuppressive or other pharmacologic therapy

PRIOR CONCURRENT THERAPY:

See Disease Characteristics
No prior chemotherapy or monoclonal antibody-based therapy for treatment of CLL
Nutraceutical treatments with no established benefit in CLL (e.g., epigallocatechin gallate or other herbal treatments) are not considered prior therapy
More than 4 weeks since prior radiotherapy
At least 4 weeks since prior major surgery

No concurrent corticosteroids

Concurrent low doses of steroids (e.g., < 10 mg of prednisone or equivalent dose of other steroid) used for treatment of non-hematologic medical conditions allowed
Prior use of corticosteroids allowed
No prior thalidomide or lenalidomide

No concurrent therapeutic doses of coumadin-derivative anticoagulants (e.g., warfarin)

Doses of ≤ 2 mg daily allowed for thrombosis prophylaxis
Prophylactic doses of low molecular weight heparin allowed