Tositumomab
Tositumomab is a murine IgG2a lambda monoclonal antibody directed against the CD20 antigen, produced in mammalian cells. Combined with radioisotope iodine 131 it was called Iodine I 131 Tositumomab. Unlabelled tositumomab together with iodine-labelled tositumomab was called Bexxar and a personlized regimen using Bexxar was approved for the treatment of relapsed or chemotherapy/rituxan-refractory Non-Hodgkin lymphoma in 2003.