<n0:ComplexDefinition xmlns:n0="http://ncicb.nci.nih.gov/xml/owl/EVS/ComplexProperties.xsd#"><n0:def-definition>A drug used to treat chronic lymphocytic leukemia (CLL) that has not gotten better with other chemotherapy. It is also being studied in the treatment of other types of cancer, including follicular non-Hodgkin lymphoma. Arzerra binds to CD20, a protein on the surface of normal B cells and most B-cell tumors. This may kill the cancer cells. It is a type of monoclonal antibody.</n0:def-definition><n0:def-source>NCI-GLOSS</n0:def-source></n0:ComplexDefinition>
<n0:ComplexDefinition xmlns:n0="http://ncicb.nci.nih.gov/xml/owl/EVS/ComplexProperties.xsd#"><n0:def-definition>A fully human, high-affinity IgG1 monoclonal antibody directed against the B cell CD20 cell surface antigen with potential antineoplastic activity. Ofatumumab binds specifically to CD20 on the surfaces of B cells, triggering complement-dependent cell lysis (CDCL) and antibody-dependent cell-mediated cytotoxicity (ADCC) of B cells overexpressing CD20. The CD20 antigen, found on over 90% of B cells, B cell lymphomas, and other B cells of lymphoid tumors of B cell origin, is a non-glycosylated cell surface phosphoprotein that acts a calcium ion channel; it is exclusively expressed on B cells during most stages of B cell development.</n0:def-definition><n0:def-source>NCI</n0:def-source></n0:ComplexDefinition>