Pentostatin, Cyclophosphamide, and Rituximab Followed By Lenalidomide in Treating Patients With Relapsed or Refractory B-Cell Chronic Lymphocytic Leukemia

DISEASE CHARACTERISTICS:

• Diagnosis of B-cell chronic lymphocytic leukemia (CLL) meeting the following criteria:

  • Peripheral blood absolute lymphocyte count greater than 5,000/mm^3
  • Lymphocytosis must comprise small to moderate size lymphocytes with no greater than 55% prolymphocytes, atypical lymphocytes, or lymphoblasts morphologically

  • Phenotypically characterized CLL defined by the following:

    • Predominant population of cells share B-cell antigens with CD5 in the absence of other pan-T-cell markers (CD3 or CD2)
    • B cell expresses either kappa or lambda light chains
    • Surface immunoglobulin with low cell surface density expression

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

  • Disease-related symptoms

    • Weight loss of 10% or more within the past 6 months
    • Extreme fatigue
    • Fevers greater than 100.5°F for 2 weeks without evidence of infection
    • Night sweats without evidence of infection
  • Evidence of progressive marrow failure manifested by the development of or worsening anemia (hemoglobin no greater than 10 g/dL) and/or thrombocytopenia (platelet count no greater than 100,000/mm^3)
  • Massive (i.e., greater than 6 cm below left costal margin) or progressive splenomegaly
  • Massive nodes or clusters (i.e., greater than 10 cm in longest diameter) or progressive adenopathy
  • Progressive lymphocytosis with an increase of greater than 50% over a 2-month period OR an anticipated doubling time of less than 6 months

• Demonstrated progression after at least 1 course of either an alkylating agent-based or purine nucleoside-based (e.g., fludarabine) regimen OR failed to achieve a meaningful response OR relapsed after prior therapy

  • Patients who have relapsed after a pentostatin-based regimen are eligible provided the response was greater than 12 months prior to study entry
• No bone marrow dysplasia related to prior therapy

PATIENT CHARACTERISTICS:

Age

• 18 and over

Performance status

• ECOG 0-2

Life expectancy

• Not specified

Hematopoietic

• See Disease Characteristics

Hepatic

• Bilirubin no greater than 2 mg/dL (unless secondary to tumor, hemolysis, or Gilbert syndrome)

Renal

• Creatinine no greater than 2.0 mg/dL OR
• Creatinine clearance ≥ 30 mL/min

Cardiovascular

• No New York Heart Association class III or IV heart failure

Other

• Not pregnant or nursing
• Negative pregnancy test
• Fertile patients must use 2 methods of effective contraception (including 1 barrier method) for at least 28 days before starting lenalidomide, while participating in the study, and for at least 28 days after discontinuation/stopping lenalidomide
• No other malignancy within the past 2 years except squamous cell or basal cell skin cancer or carcinoma in situ of the cervix

PRIOR CONCURRENT THERAPY:

Biologic therapy

• See Chemotherapy
• At least 8 weeks since prior rituximab

Chemotherapy

• See Disease Characteristics
• At least 6 weeks since prior chemotherapy

• At least 1 year since prior pentostatin, cyclophosphamide, and rituximab (PCR) therapy

  • PCR therapy at least 1 year prior to study entry allowed
• No prior lenalidomide

Endocrine therapy

• Not specified

Radiotherapy

• Not specified

Surgery

• Not specified

Other

• No concurrent oral or IV antibiotics for active infection