Pentostatin, Cyclophosphamide, and Rituximab Followed By Campath-1H in Patients With Relapsed or Refractory B-Cell CLL

Inclusion criteria:

* 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
* 18 and over
* ECOG Performance Status 0-2
* Bilirubin no greater than 2 mg/dL (unless secondary to tumor, hemolysis, or Gilbert syndrome)
* Creatinine no greater than 2.0 mg/dL
* Creatinine clearance ≥ 30 mL/min
* 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
* At least 8 weeks since prior rituximab
* 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

Exclusion criteria:

* Bone marrow dysplasia related to prior therapy
* New York Heart Association class III or IV heart failure
* Prior lenalidomide
* Other malignancy within the past 2 years except squamous cell or basal cell skin cancer or carcinoma in situ of the cervix
* Pregnant or nursing
* Concurrent oral or IV antibiotics for active infection