e14017 Background: The ability of Natural Killer (NK) cells to kill tumor targets has been extensively studied in various hematological malignancies. However, NK cell therapy directed against solid tumors is under early development. Epidermal growth factor receptor (EGFR) targeted therapies using monoclonal antibodies (moAbs) such as Cetuximab and Panitumumab are widely used for the treatment of colorectal cancer and head and neck squamous cell carcinoma. The clinical efficacy of this approach has been hampered by several factors, including mutations in RAS, allowing tumors to escape from anti-EGFR moAb therapy. It is well established that NK cells can kill tumor cells by natural cytotoxicity and additionally be activated upon binding of moAbs through Fc receptors (FcγRIIIa) mediating antibody dependent cellular cytotoxicity (ADCC). Methods: In the current setting we combined isolated and activated Peripheral Blood NK cells (PBNK) with anti-EGFR moAbs to increase killing of EGFR+cancer cell lines, includi...