Rituximab (Anti-Human CD20 type I, Chimeric Antibody) (Synonyms: IDEC-C2B8)

Rituximab is a human/murine, chimeric anti-CD20 monoclonal antibody with established efficacy, and a favorable and well-defined safety profile in patients with various CD20-expressing lymphoid malignancies, including indolent and aggressive forms of B-cell non-Hodgkin lymphoma [1].

Intravenously administered rituximab was granted regulatory approval in 1997 by the US Food and Drug Administration and in 1998 by the European Medicines Agency for use in relapsed/refractory indolent non-Hodgkin lymphomas. Approvals for use in chronic lymphocytic leukemia followed in 2009 and 2010, respectively [1].

Rituximab binds with high affinity and specificity to the CD20 antigen, which is expressed on the vast majority of malignant B cells. The apparent affinity constant of rituximab for human CD20, as determined by Scatchard analysis using a human lymphoblastoid cell line, is approximately 5.2 nmol/L [2]. Rituximab provides significant, clinically meaningful benefits to patients with active rheumatoid arthritis also. In patients with active rheumatoid arthritis despite methotrexate treatment, a single course of two infusions of rituximab, alone or in combination with either cyclophosphamide or continued methotrexate, provided significant improvement in disease symptoms at both weeks 24 and 48 [3].

References:
[1]. Salles G, Barrett M, FoÀ R, et al. Rituximab in B-cell hematologic malignancies: a review of 20 years of clinical experience. Adv Ther. 2017;34(10):2232-2273.
[2]. Reff ME, Carner K, Chambers KS, et al. Depletion of B cells in vivo by a chimeric mouse human monoclonal antibody to CD20. Blood. 1994;83:435-45.
[3]. Edwards JC, Szczepanski L, Szechinski J, et al. Efficacy of B-cell-targeted therapy with rituximab in patients with rheumatoid arthritis. N Engl J Med 2004;350:2572-2581