Anti-Human EGFR (Panitumumab)

Epidermal growth factor receptor (EGFR, also known as ErbB1 or HER-1) belongs to the receptor tyrosine kinase superfamily and is a transmembrane glycoprotein that activates various signaling pathways fundamental to cellular proliferation, differentiation, and survival1, 2.

EGFR plays important roles during embryogenesis, organogenesis, and in the growth, differentiation, maintenance, and repair of adult tissues2.

EGFR is also a host factor that facilitates viral entry for hepatitis B4, hepatitis C5, and gastroenteritis6 and plays a role in SARS-CoV-2 infection7, 8, 9.

Dysregulation, somatic mutation, and/or altered signaling of EGFR is associated with neurological diseases (e.g.

Parkinson’s2, Alzheimer’s1, 2, and amyotrophic lateral sclerosis2) and multiple cancers (lung, glioblastoma, brain, breast, colorectal, ovarian)10.

Additionally, in cancer, binding of ligands to EGFR is associated with aberrant cell proliferation, invasion, metastasis, angiogenesis, and decreased apoptosis11.

As such, EGFR is the target of multiple cancer therapies, including monoclonal humanized antibodies, such as panitumumab, as well as selective small molecule inhibitors.

Panitumumab was generated in a XenoMouse IgG2 strain immunized with the human cervical epidermal carcinoma cell line A43112.

Panitumumab binds specifically to EGFR and inhibits the growth and survival of selected human tumor cell lines over-expressing EGFR in vitro and in vivo13.

Panitumumab binds EGFR with high affinity, blocking the binding of both EGF and TGF-α, and preventing EGF-activated EGFR tyrosine autophosphorylation and downstream activation of receptor-associated kinases12.

Panitumumab inhibits cell growth, tumor cell activation, in vitro tumor cell proliferation12, and metastasis13.

Panitumumab also induces apoptosis and decreases proinflammatory cytokine and vascular growth factor production13.

Additionally, upon binding, panitumumab causes EGFR internalization in tumor cells12.

Panitumumab was approved in the United States for the treatment of some patients with EGFR-expressing metastatic colorectal cancer14, 15.