Synergistic therapeutic activity of chimeric G250-TNF and IFNγ for the treatment of renal cell cancer

16009 Background: Renal cell cancer (RCC) is a chemotherapy and radiation resistant disease with high morbidity and mortality when detected at advanced stage. RCC cells express the G250/CAIX antigen at high levels and can be targeted very efficiently with monoclonal antibodies. To deliver human tumor necrosis factor (TNF) we engineered a modified G250 antibody carrying TNF as dimerized CH2/CH3 truncated IgG1-TNF fusion protein which is able to induce TNF-receptor 1 and TNF-receptor 2 dependent bioactivity in a locally restricted manner. Methods: The N-terminal domain of human TNF was linked to the chimeric G250 antibody by molecular engineering. High-level expression of the recombinant fusion protein using NSO cells was achieved with about a 270 mg/l of culture supernatant. Cytotoxicity assays in vitro and biodistribution and efficacy assays in vivo were performed using standard methods. Results: We established an antibody fusion protein that consists of human TNF and chimeric antibody cG250. Bifunctional...