Targeting a unique EGFR epitope with monoclonal antibody 806 activates NF-κB and initiates tumour vascular normalization

Abstract

Monoclonal antibodies (mAbs) and tyrosine kinase inhibitors targeting the epidermal growth factor receptor (EGFR), which is often pathogenetically overexpressed or mutated in epithelial malignancies and glioma, have been modestly successful, with some approved for human use. MAb 806 was raised against de2-7EGFR (or EGFRvIII), a constitutively active mutation expressed in gliomas, but also recognizes a subset (<10%) of wild-type (wt) EGFR when it is activated by autocrine loop, overexpression or mutation. It does not bind inactive EGFR in normal tissues like liver. Glioma xenografts expressing the de2-7EGFR treated with mAb 806 show reduced receptor autophosphorylation, increased p27 KIP1 and..