Lower But More Frequent Dose Rituximab to Treat Chronic Lymphocytic Leukemia

This study will test the safety and effectiveness of using lower-dose rituximab given more frequently for treating chronic lymphocytic leukemia (CLL). Studies have shown that, used once a week for 4 weeks, rituximab was effective in up to 25 percent of patients with CLL. New evidence shows that using lower and more frequent doses of rituximab can be more effective in destroying leukemia cells and produce a better treatment response. Patients 21 years of age and older with CLL who have received treatment with fludarabine may be eligible for this study. Participants take rituximab for 12 weeks. One dose of the drug is infused through an arm vein over about 30 minutes on either day 1 (the first dose) or day 3 (the second dose). All other doses are given as an injection under the skin. After the first week, patients can choose to do these injections at home. Rituximab will be given 3 times a week for a total of 12 weeks. Other medications are given to reduce the side effects and allergic reactions to the drug. In addition to treatment, patients undergo the following tests and procedures: Before treatment * Medical history, physical examination, electrocardiogram (EKG) and blood tests. * Bone marrow and lymph node biopsies (surgical removal of a small tissue sample). * Computed tomography (CT) and positron emission tomography (PET) scans. CT uses special x-rays to provide images of the neck, chest, abdomen and pelvis. PET uses a radioactive sugar to identify areas of disease. During treatment (study weeks 1-12) * Medical history and physical examinations at weeks 3, 6 and 12 to evaluate drug side effects, plus weekly telephone checks and interim visits when needed. * Blood tests every other week to evaluate blood counts. Evaluations after treatment (follow-up 3 months to 12 months) * Blood tests at follow-up visits at 3, 6, 9 and 12 months after treatment to evaluate blood counts. * Bone marrow aspiration and biopsy at 3 months after treatment to examine the effe