Murine IgG2a lambda monoclonal antibody in opposition to CD20 antigen (2 heavy chains of 451 residues, 2 lambda chains of 220 residues). it is produced in an antibiotic-loose subculture of mammalian cells. it is able to be covalently related to Iodine 131 (a radioactive isotope of iodine).
Tositumomab binds to the CD20 antigen, which is predominantly expressed on mature B cells and on >90% of B-cell non-Hodgkin's lympohomas. The antibody leads to selective killing of B-cells.
For treatment of non-Hodgkin's lymphoma (CD20 positive, follicular)
Binds to the CD20 antigen which is found on mature B lymphocytes. The antibody binding appears to induce apoptosis, complement-dependent cytotoxicity and cell death through ionizing radiation.