RETRACTED: Silencing EGFR/HER3 signaling with a novel anti-EGFR domain II/IV antibody.

Dysfunction of the epidermal growth factor receptor (EGFR) family, is the key process in tumorigenesis, and anti-EGFR therapeutic strategies such as cetuximab therapy now are used in the treatment of cancer. However, resistance to cetuximab is commonly reported. Comprehensive blockade of EGFR signaling using different antibodies might be critical to treat cancer effectively and limit drug resistance with potent novel mechanisms. Here, we launch a screen of a phage display library to isolate a novel anti-EGFR antibody, YAH627. YAH627 exhibits superior efficacy in inhibiting EGFR activation, particularly by blocking EGF/HRG-induced EGFR/HER3 heterodimerization and signaling, verifying it as an impressive candidate for clinical translation as a therapeutic antibody. Moreover, we use epitope analysis validates that the epitope of this antibody is within domains II and IV of EGFR and traps EGFR in a silent conformation. Moreover, combining YAH627 with cetuximab produces synergistic antitumor activity in vitro and in vivo. Taken together, our report establishes that YAH627 possesses a novel mechanism of action that, in combination with cetuximab, may achieve clinical efficacy in EGFR-driven cancers.