Rituximab

Use

Rituximab (Rituxan, Chimeric) is an MAb directed againstthe CD20 antigen expressed on the surfaces of normal andmalignant B lymphocytes. The MAb is produced in mammalian(CHO) suspension culture and is a chimeric(murine/human) MAb of the IgG1 κ type. The protein is composed of murine light and heavy chain variable regionsand human constant regions. Rituximab is indicated for thetreatment of patients with relapsed or refractory, low-gradeor follicular, CD20(+) B-cell non-Hodgkin lymphoma.Rituximab binds specifically to antigen CD20 (human Blymphocyte–restricted differentiation antigen, a hydrophobictransmembrane protein expressed on pre-B and matureB lymphocytes). CD20 is a protein of 35 to 37 kDa, and itmay play a role in B cell activation and regulation and maybe a calcium ion channel. The antigen is also expressed onmore than 90% of non-Hodgkin lymphoma B cells but is notfound on hematopoietic stem cells, pro-B cells, normalplasma cells, or other normal tissues. CD20 regulates theearly steps in the activation process for cell cycle initiationand differentiation.