What type of monoclonal antibody is Rituximab?

Rituximab is classified as a chimeric monoclonal antibody because it is derived from both human and murine (mouse) sources. Specifically, Rituximab is composed of a mouse variable region that recognizes the CD20 antigen found on B cells, fused with a human constant region. This design allows the antibody to effectively target and mediate destruction of B cells while minimizing the risk of immunogenicity that is often associated with fully murine antibodies.

Chimeric antibodies aim to combine the specificity of murine antibodies with the reduced immune response typically seen with human antibodies, making them more tolerable for human patients. This mix contributes to the therapeutic efficacy of Rituximab in treating conditions like non-Hodgkin lymphoma and rheumatoid arthritis. Understanding the characteristics of different monoclonal antibodies, such as whether they are fully human, murine, chimeric, or humanized, helps clinicians choose the appropriate therapy tailored to patient needs and the specific disease being treated.