What is Cetuximab?

Cetuximab (Erbitux) is a chemotherapy/biotherapy medication known as epidermal growth factor receptor (EGFR) inhibitor. It is used to treat metastatic colorectal cancer and squamous cell head and neck cancer. It is also used to treat non-small cell lung cancer, expressing the EGFR as well as unresectable squamous cell skin cancer; these indications are non-FDA approved, off-label. Cetuximab is formed from both human and murine antibodies to target the epidermal growth factor receptor. When cetuximab binds to the EGFR, the cell essentially no longer receives signal to continue growing, thus leading to cell death. Additionally, nutrients to the cell are cut off to some degree.

How is it administered?

Cetuximab is administered intravenously as an infusion. The first infusion is known as the loading dose; more medication is administered initially to increase the concentration of the medication circulating in the body. This first dose, the loading dose, is administered over two hours. Subsequent doses are administered over 1 hour, depending on tolerability of the first dose. Pre-medications are typically given prior to the start of each infusion to reduce the likelihood of an allergic reaction to cetuximab. It is usually administered every two weeks.

What to expect:

Cetuximab can reduce the body’s ability to fight an infection. The development of a red, acne-like rash is very typical during treatment. Sometimes cetuximab is given at the same time radiation therapy; this may exasperate the rash and its severity. Neuropathy or tingling and numbness in the extremities is another common side effect of cetuximab. Other side effects include: fatigue, weakness, insomnia, weight loss, diarrhea, stomach pain, increases in liver enzymes, muscle pain, eye infections and shortness of breath. It is possible to develop an allergic reaction and form antibodies to cetuximab. A rare but serious side effect is kidney failure. Laboratory tests will be performed routinely throughout the course of therapy to help manage and monitor the development of these side effects.