DISEASE CHARACTERISTICS:

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

  • Lymphocytosis of monoclonal B cells co-expressing ≥ 1 B-cell marker (CD19, CD20, or CD23) and CD5 in peripheral blood or lymph node
  • Bone marrow with ≥ 30% mononuclear cells having the CLL/SLL phenotype
  • Prolymphocytes ≤ 55%

• Meets ≥ 1 of the following International Workshop on CLL 2008 "Indications for Treatment" Guidelines:

  • Evidence of progressive marrow failure as manifested by the development or worsening of anemia and/or thrombocytopenia
  • Massive (i.e., > 6 cm below the left costal margin), progressive, or asymptomatic splenomegaly
  • Massive (i.e., > 10 cm in longest diameter), progressive, or symptomatic lymphadenopathy
  • Progressive lymphocytosis with an increase of > 50% over a 2-month period or lymphocyte-doubling time < 6 months (factors contributing to lymphocytosis or lymphadenopathy other than CLL [e.g, infections] must be excluded)
  • Autoimmune anemia and/or thrombocytopenia poorly responsive to corticosteroids or other standard therapy

  • Has ≥ 1 of the following disease-related symptoms*:

    • Unintentional weight loss ≥ 10% within the past 6 months
    • Significant fatigue (i.e., ECOG performance status ≥ 2; cannot work or unable to perform usual activities)
    • Fevers of > 100.5°F or 38.0°C for ≥ 2 weeks without other evidence of infection
    • Night sweats for > 1 month without evidence of infection NOTE: *Hypogammaglobulinemia or monoclonal or oligoclonal paraproteinemia by itself does not constitute a basis to initiate treatment

• Disease resistant or refractory to standard chemotherapy regimens containing alkylating agents and/or purine analogues, as defined by any of the following:

  • Disease progression during treatment with 2 courses of chemotherapy
  • Failed to achieve a partial response or complete response after ≥ 2 courses of chemotherapy
  • No response to treatment or stable disease after ≥ 2 courses of chemotherapy
  • Disease progression within 6 months after completion of chemotherapy
  • CLL with cytogenetic changes documenting the loss of the short arm of chromosome 17 (17p-) associated with the loss of p53
• Measurable disease
• No Richter transformation

PATIENT CHARACTERISTICS:

• ECOG performance status 0-2
• Platelet count ≥ 50,000/mm³
• Hemoglobin ≥ 10 g/dL (erythropoietin or transfusion allowed)
• Total bilirubin ≤ 2.5 times upper limit of normal (ULN)
• ALT ≤ 2.5 times ULN
• PT/INR ≤ 1.5
• PTT ≤ 1.5 times ULN
• Creatinine ≤ 2 times ULN OR creatinine clearance ≥ 30 mL/min
• Not pregnant or nursing
• Negative pregnancy test
• Fertile patients must use effective contraception
• No untreated autoimmune hemolytic anemia or immune thrombocytopenia
• No active symptomatic fungal, bacterial, and/or viral infection
• No HIV-1, HIV-2, HTLV-I, or HTLV-II seropositivity
• No cytomegalovirus seropositivity by PCR
• No syphilis seropositivity by VDRL
• No acute hepatitis A or C seropositivity
• No acute or chronic hepatitis B infection
• No illness or condition that, in the opinion of the investigator, may affect safety of treatment or evaluation of study endpoints

PRIOR CONCURRENT THERAPY:

• See Disease Characteristics
• Recovered from prior antineoplastic therapy
• More than 4 weeks since prior and no other concurrent chemotherapy (e.g., purine analogues, alkylating agents, or corticosteroids), antibody therapy, immunotherapy, radiotherapy, or investigational drugs