Lower But More Frequent Dose Rituximab to Treat Chronic Lymphocytic Leukemia

Rituximab is FDA approved for the treatment of relapsed or refractory low grade or follicular CD20+ B cell non Hodgkin's lymphoma (375 mg/m(2) IV infusion once weekly for 4 or 8 doses). Recently, rituximab (anti CD20) has been introduced to CLL treatment regimens and has become an attractive choice in combination chemotherapy or as single agent treatment. Rituximab has been shown to be effective at lower doses than 375 mg/m(2) when given more frequently. Several theoretical considerations and supporting laboratory evidence suggest that a fractionated dosing schedule using low-dose rituximab could be more effective than the current i.v. schedule of high-dose rituximab. Indeed, preliminary clinical evidence suggests that low-dose rituximab at 20mg/m2 i.v. 3-times per week can lead to steady clearance of leukemic cells without inducing substantial loss of targeted CD20. This is a Phase I/II , single agent study which will evaluate the safety and feasibility of subcutaneous rituximab (Rituxan) administered at 20 mg/day three times a week for 12 weeks in subjects with CLL. Patients need to have had prior treatment with fludarabine, and have an elevated absolute lymphocyte count. The primary objective will be to test the safety and feasibility of giving rituximab subcutaneously. We will also obtain as a secondary endpoint an early estimate of efficacy as evidenced by (a) shrinkage of lymphadenopathy and/or (b) improvement in blood values and bone marrow biopsy findings.