Approaching untargetable tumor-associated antigens with antibodies

Approved therapeutic antineoplastic antibodies have targeted extracellular or cell-surface molecules. ESK1 is the first fully human T-cell receptor-like antibody targeting an intracellular tumor-associated antigen, Wilm's tumor 1 (WT1). In murine xenograft models, ESK1 exhibits a high specificity and exert robust antineoplastic effects against human cancers that express WT1 epitopes on HLA-A201 molecules.