Radioimmunotherapy as a therapeutic option for Non-Hodgkin's lymphoma

Radioimmunotherapy (RIT) represents a relatively new antibody-based radiopharmaceutical treatment for patients with various kinds of tumors. Although the field has a long history of preclinical and clinical investigations using many different agents, to date, only 2 of these immunologically targeted radiopharmaceuticals have been cleared for commercial sale. Both of these agents ((90)Y-ibritumomab tiuxetan or "Zevalin" [Biogen-Idec, Boston, MA] and (131)I-tositumomab or "Bexxar" [GlaxoSmithKline Research, Triangle Park, NC]) are directed against the CD20 surface antigen found on normal mature B cells and greater than 95% of B-cell non-Hodgkin lymphoma (NHL). Both compounds produce similar impressive clinical outcomes (approximately 20%-40% complete response rates and 60%-80% overall response rates for patients with indolent B-cell NHL). Current protocol-based investigations of anti-CD20 RIT relate to new clinical uses and new CD20(+) targets.