Iodine I 131 tositumomab (Corixa Corporation)

Iodine I 131 tositumomab, marketed under the brand name Bexxar, is a radioimmunotherapy regimen developed by Corixa Corporation and GSK for the treatment of CD20-positive follicular non-Hodgkin's lymphoma. The therapy consists of two components: an unlabeled murine monoclonal antibody (tositumomab) and a radiolabeled version (iodine I 131 tositumomab). Tositumomab binds specifically to the CD20 antigen on the surface of normal and malignant B-lymphocytes. The mechanism of action involves antibody-dependent cellular cytotoxicity (ADCC), complement-dependent cytotoxicity (CDC), and apoptosis, supplemented by the targeted delivery of ionizing radiation from the iodine-131 isotope, which induces DNA damage in both the target cells and adjacent cells via the "crossfire" effect. Although FDA-approved in 2003, Bexxar was discontinued by GSK in 2014 due to commercial reasons and the emergence of alternative therapies like rituximab.

Brand names

Bexxar

Other names

tositumomab and iodine I 131 tositumomabI-131 anti-B1 antibodyI131 anti-B1 antibodyI 131 anti-B1 antibody