Cetuximab by Ray Sahelian, M.D.

Erbitux ( cetuximab ) is a pharmaceutical drug used to treat patients with advanced colon cancer that has spread to other parts of the body. Cetuximab is the first monoclonal antibody approved to treat this type of cancer and is indicated as a combination treatment to be given intravenously with irinotecan, another drug approved to fight colorectal cancer, or alone if patients cannot tolerate irinotecan.

Cetuximab mechanism of action
The role of epidermal growth factor receptor (EGFR)-driven signaling in different stages of colorectal carcinogenesis, as well in the acquisition of therapy resistance, has been established. Multiple strategies have been developed for the therapeutic targeting of EGFR. Cetuximab is a chimeric monoclonal antibody selective for EGFR with efficacy alone or in combination with irinotecan in the treatment of metastatic colorectal cancer patients, who have progressed to using irinotecan-containing chemotherapy. The combination of cetuximab with standard chemotherapy regimens such as irinotecan/ 5-FU/folinic acid (FA) or oxaliplatin/5-FU/FA are currently being investigated in Phase III trials for chemotherapy-naive patients with metastatic colorectal cancer.

Cetuximab Side Effect
A 71-year-old man exhibited an acute acneiform rash affecting the face and the upper trunk about 2 weeks after starting cetuximab, an epidermal growth factor (EGF) receptor antagonist treatment for metastatic colon cancer. The skin eruption faded after stopping cetuximab and applying topical corticosteroids. The reexposure to cetuximab 3 weeks later provoked a more extended relapse of the skin rash, which then clinically and histologically corresponded to transient acantholytic dermatosis . While the acneiform cutaneous side effects of the EGF receptor antagonists are interpreted as a result of the direct interference with pilosebaceous follicle homeostasis, in this case an acrosyringium-related pathogenesis might be postulated. Applying topical corticosteroids and emollients, the cetuximab therapy could be pursued.

Erbitux cetuximab