A Phase II Trial of Alemtuzumab and Rituximab in Patients With Previously Untreated CLL

DISEASE CHARACTERISTICS: * Diagnosis of B-cell chronic lymphocytic leukemia (CLL)\*, as defined by the following criteria: * Peripheral blood absolute lymphocyte count \> 5,000/mm³ * Small- to moderate-size lymphocytes with \< 55% prolymphocytes, atypical lymphocytes, or lymphoblasts * Phenotypically characterized B-CLL expressing CD20 and CD52, as defined by the following: * Predominant population of cells share B-cell antigens with CD-5 in the absence of other pan-T-cell markers (e.g., CD-3, CD-2) * B-cell expresses either lambda or kappa light chains * Surface immunoglobulin with low-cell surface density expression NOTE: \*Presence of splenomegaly, hepatomegaly, or lymphadenopathy are not required for the diagnosis of CLL * Requires therapy, as indicated by ≥ 1 of the following criteria: * Unintentional weight loss \> 10% within the past 6 months * Extreme fatigue (i.e., ECOG performance status 2) * Fevers \> 100.5°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 of anemia (hemoglobin \< 10 g/dL) and/or thrombocytopenia (platelet count \< 100,000/mm³) * Massive (i.e., \> 6 cm below left costal margin) or progressive splenomegaly * Massive nodes/clusters (\> 5 cm), progressive symptomatic adenopathy, or adenopathy resulting in end-organ damage * Progressive lymphocytosis with an increase of \> 50% over 2 months or an anticipated doubling time \< 6 months * Marked hypogammaglobulinemia or the development of a monoclonal protein in the absence of any of the above criteria for active disease is not sufficient for eligibility PATIENT CHARACTERISTICS: * ECOG performance status 0-2 * ANC ≥ 1,000/mm³\* * Platelet count ≥ 50,000/mm³\* * Hemoglobin ≥ 10 g/dL\* * Serum creatinine ≤ 2.0 mg/dL OR creatinine clearance \> 40 mL/min * Bilirubin \< 2 mg/dL * AST and ALT ≤ 2 times normal (unless secondary to tumor infiltration/lymphadenopathy) * Not pregnant or nursing * Negative pregnancy test * Fertile patients must use effective contraception during and for 6 months after completion of study treatment * No active autoimmune anemia or thrombocytopenia * No active infection requiring oral or intravenous antibiotics * No second malignancy, other than basal cell carcinoma of the skin or in situ carcinoma of the cervix, unless curatively treated ≥ 2 years ago NOTE: \*If cytopenias are due to degree of bone marrow involvement, patient may be eligible at the discretion of the principal investigator. PRIOR CONCURRENT THERAPY: * Prior corticosteroid therapy allowed * No prior cytotoxic therapy (other than corticosteroids)