tositumomab

Tositumomab is a murine IgG2a lambda monoclonal antibody that targets the CD20 antigen on B lymphocytes. It is primarily used in combination with the radioactive isotope iodine-131 (I-131) as a radioimmunotherapy regimen for the treatment of CD20-positive, follicular non-Hodgkin's lymphoma, particularly in patients whose disease is refractory to rituximab and has relapsed following chemotherapy. The mechanism of action involves binding to the CD20 antigen on malignant B cells, leading to their destruction through both immune-mediated mechanisms and targeted delivery of cytotoxic radiation from the attached I-131. This dual approach allows for selective killing of cancerous B cells while sparing most other tissues[2][3][4][5].

Brand names

Bexxar

Other names

iodine I 131 tositumomabtositumomab and iodine I 131 tositumomab