Early or Delayed Fludarabine and Rituximab in Treating Patients With Previously Untreated Chronic Lymphocytic Leukemia

Eligibility Criteria for Pre-Registration:

1. Patients must be within 6 months of the initial flow cytometric confirmation of B-cell chronic lymphocytic leukemia (CLL). This interval begins with the initial flow cytometric confirmation of disease.
2. Clinical and immunophenotypic evidence of CLL including:

   2.1 An absolute lymphocytosis of \> 5,000/μL
   * Morphologically, the lymphocytes must appear mature with \< 55% prolymphocytes.
   * Local institution lymphocyte phenotype must reveal a predominant B-cell monoclonal population sharing a B-cell marker (CD19, CD20, CD23) with the CD5 antigen, in the absence of other pan-T-cell markers.
   * Additionally, the B-cells must be monoclonal with regard to expression of either κ or λ and have surface immunoglobulin expression of low density.
   * Patients with bright surface immunoglobulin levels must have CD23 coexpression and absence of t(11;14) on interphase cytogenetics or have negative tumor protein staining for cyclin D1.

   2.2 Staging - Patients must be in the low category (i.e., only stages 0 or I) of the modified three-stage Rai staging system as described in the protocol.
3. Patients should not have evidence of active disease as demonstrated by any of the following criteria:

   * Splenomegaly and/or massive/progressive lymphadenopathy that would require therapy
   * Presence of weight loss \> 10% over the preceding 6 month period
   * Grade 2 or 3 fatigue
   * Fevers \> 100.5°F or night sweats for greater than 2 weeks without evidence of infection
   * Progressive lymphocytosis with an increase of \> 50% over a 2 month period or an anticipated doubling time of less than 6 months.
4. Prior Treatment: No prior therapy for CLL including corticosteroids for autoimmune complications that have developed since the initial diagnosis of CLL.
5. Age ≥ 18 years
6. Performance Status 0 - 1.
7. No HIV disease. Due to alterations in host immunity, patients known to have HIV infection may not be enrolled.
8. Non-pregnant and non-nursing. Due to the unknown teratogenic potential of chemotherapy, pregnant or nursing women may not be enrolled. Women and men of reproductive potential should agree to use an effective means of birth control.
9. Required Initial Laboratory Values:

   * Creatinine ≤ 1.5 x upper limit of normal

Eligibility Criteria for Registration (to Low-Risk Cohort or High-Risk Cohort Randomization between Early Intervention Versus Observation with Later Treatment)

1. Successful determination of IgVH mutational status by reference laboratory.
2. Absence of progression of CLL, i.e., absence of the following:

   * Progressive splenomegaly and/or lymphadenopathy on two independent measures spaced two weeks apart. If one assessment notes progression, this should be repeated prior to re-registration.
   * Development of anemia (hemoglobin \< 11 g/dL) or thrombocytopenia (platelets \< 100,000/μL).
   * Progressive lymphocytosis with an increase of \> 50% over a 2 month period or an anticipated doubling time of less than 6 months.
   * Symptoms referable to CLL, including weight loss \> 10% over the preceding 6 month period; grade 2 or 3 fatigue; or fevers \> 100.5°F and/or night sweats for greater than 2 weeks without evidence of infection.
3. Required Laboratory Value:

   * Creatinine ≤ 1.5 x upper limit of normal