DISEASE CHARACTERISTICS:

• Diagnosis of B-cell chronic lymphocytic leukemia (CLL)*, as defined by the following phenotypic characteristics:

  • Predominant population of cells share both B-cell antigens (CD19, CD20, or CD23) as well as the T-cell antigen (CD-5), in the absence of other pan-T-cell markers (CD-3, CD-2, etc.)

    • Mantle cell lymphoma must be excluded by demonstrating the absence of the t(11;14) by fluorescent in situ hybridization (FISH)
  • Dim surface immunoglobulin expression
  • Exclusively kappa and lambda light chains NOTE: *Splenomegaly, hepatomegaly, or lymphadenopathy are not required for the diagnosis of CLL

• Peripheral blood absolute lymphocyte count > 5,000/mm^3

  • Lymphocytosis must consist of small to moderate size lymphocytes, with ≤ 55% prolymphocytes, atypical lymphocytes, or lymphoblasts morphologically

• Requires chemotherapy, as indicated by any of the following:

  • Disease related symptoms, including the following:

    • Weight loss ≥ 10% within the previous 6 months
    • Extreme fatigue
    • 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 anemia (hemoglobin ≤ 10 g/dL) and/or thrombocytopenia (platelet count ≤ 100,000/mm^3)
  • Massive (i.e., > 6 cm below left costal margin) or progressive splenomegaly
  • Measurable and progressive lymphadenopathy
  • Measurable (i.e., > 5,000/mm^3) and progressive lymphocytosis
• Progressive disease or relapsed after or refractory to 1 course of an alkylating agent-based or purine nucleoside-based (e.g., fludarabine) regimen
• No marrow function attributable to dysplasia related to prior therapy

PATIENT CHARACTERISTICS:

• ECOG performance status 0, 1, or 2

• Serum creatinine < 2 mg/dL

  • If serum creatinine > 1.5 mg/dL but < 2 mg/dL, creatinine clearance must be ≥ 30 mL/min
• Platelet count > 30,000/mm^3
• Direct bilirubin ≤ 2 mg/dL
• Not pregnant or nursing
• Negative pregnancy test
• Fertile patients must use effective contraception
• No other second malignancy within the past 2 years except squamous cell or basal cell carcinoma of the skin or in situ carcinoma of the cervix
• No New York Heart Association class III or IV heart failure
• No blood pressure > 150/90 mm Hg
• No unstable angina
• No myocardial infarction or stroke within the past 6 months
• No clinically significant peripheral vascular disease
• No evidence of bleeding diathesis or coagulopathy
• No significant traumatic injury within the past 28 days

• Urine protein:creatinine (UPC) ratio ≤ 1.0

  • Patients with a UPC ratio > 1.0 must undergo a 23-hour urine collection and must demonstrate < 1 gram of protein per day
• No abdominal fistula, gastrointestinal perforation, or intra-abdominal abscess within the past 6 months
• No serious, non-healing wound, ulcer, or bone fracture
• No active infections requiring oral or intravenous antibiotics
• No active bleeding or pathological conditions that carry a high risk of bleeding (e.g., known varices)
• No thrombocytopenia requiring transfusion

PRIOR CONCURRENT THERAPY:

• See Disease Characteristics
• More than 4 weeks since prior participation in an experimental drug study
• At least 8 weeks since prior rituximab
• At least 6 weeks since prior chemotherapy
• More than 28 days since prior major surgery or open biopsy
• More than 7 days since prior minor surgery, fine needle aspirations, or core biopsies
• No concurrent major surgery
• No concurrent participation in another experimental drug study
• Concurrent full-dose warfarin or low molecular weight heparin allowed provided patient is on a stable dose AND INR is in range