Chronic Lymphocytic Leukemia |
1 Hematology Branch, NHLBI, of the National Institutes of Health, Bethesda, MD
2 Department of Biochemistry and Molecular Genetics, University of Virginia School of Medicine, Charlottesville, VA
3 Department of Pharmacy, Clinical Center, of the National Institutes of Health, Bethesda, MD, USA
Correspondence: Adrian Wiestner MD, PhD, Hematology Branch, NHLBI, NIH Bldg. 10, CRC 3-5140, 10 Center Drive, Bethesda, MD 20892-1202 USA. E-mail: wiestnera{at}mail.nih.gov / Ronald P. Taylor, PhD, Department of Biochemistry and Molecular Genetics, University of Virginia School of Medicine, Charlottesville, VA, USA. E-mail: rpt{at}virginia.edu
A pilot study previously demonstrated that thrice-weekly, fractionated-dose intravenous rituximab (RTX) limits CD20 loss from chronic lymphocytic leukemia (CLL) B cells, thereby enhancing immunotherapeutic targeting. Here, we investigated the feasibility of giving 20 mg rituximab subcutaneously thrice weekly for up to 12 weeks in 4 previously treated CLL patients. Subcutaneous rituximab was well-tolerated with minimal injection site reactions; a variable degree of efficacy was observed, likely influenced by the size of the patients B cell/CD20 burden. Subcutaneous RTX largely preserved CD20 expression on leukemic cells but the most effective therapeutic dosing regimen needs to be established (ClinicalTrials.gov Identifier: NCT00366418).
Key words: rituximab, subcutaneous, CD20 shaving, antigenic modulation, chronic lymphocytic leukemia.