For treatment of EGFR-expressing metastatic colorectal cancer in patients who are refractory to other irinotecan-based chemotherapy regimens. Cetuximab is also indicated for treatment of squamous cell carcinoma of the head and neck in conjucntion with radiation therapy.
Used in the treatment of colorectal cancer, cetuximab binds specifically to the epidermal growth factor receptor (EGFr, HER1, c-ErbB-1) on both normal and tumor cells. EGFr is over-expressed in many colorectal cancers. Cetuximab competitively inhibits the binding of epidermal growth factor (EGF) and other ligands, such as transforming growth factor–alpha. Binding of cetuximab to the EGFr blocks phosphorylation and activation of receptor-associated kinases, resulting in inhibition of cell growth, induction of apoptosis, decreased matrix metalloproteinase secretion and reduced vascular endothelial growth factor production.
mechanism of action
Cetuximab binds to the epidermal growth factor receptor (EGFr) on both normal and tumor cells. EGFr is over-expressed in many colorectal cancers. Cetuximab competitively inhibits the binding of epidermal growth factor (EGF) and TGF alpha, thereby reducing their effects on cell growth and metastatic spread.
Single doses of cetuximab higher than 500 mg/m2
have not been tested. There is no experience with overdosage in human clinical trials.