ABSTRACT
Radioimmunotherapy (RIT) has been the subject of investigations since the early
1970s. A tumor antigen-binding protein is labeled with a therapeutic radionuclide
and administered systemically-the radionuclide decay results in lethal radiation
that putatively destroys cancer cells. RIT of lymphoma has shown great promise
(1-5), and two anti-CD20 agents are approved by the Food and Drug Adminis-
tration (FDA) for clinical use. There are no pivotal or phase 3 trials in solid tumor
RIT, partly because the need for nonimmunogenic proteins necessitated the
development of chimeric and humanized antibodies, and also because tumor
radiation-absorbed dose with radiolabeled intact immunoglobulin has been
inadequate in most of the systems studied.
