Quick Facts About: Cetuximab
Alternative names
Erbitux
FDA approved?
Yes, in 2004.
Used to treat
Cetuximab is used in metastatic colorectal cancer treatment.
Administration and dosage
*All dosages indicated here are specific to colorectal cancer treatment.
Cetuximab is administered intravenously.
Dosage is dependent on drug combination in the treatment regimen and is based on the patient’s body surface area (milligram per square meter, mg/m2).
Cetuximab can be used in monotherapy or in combination with other treatment drugs. Cetuximab is a treatment option for EGFR-expressing, RAS-wild type patients.
Monotherapy:
In cases where oxaliplatin and irinotecan based treatments fail, and for patients who are intolerant of irinotecan, cetuximab can be administered.
Combination therapy:
Cetuximab may also be considered as a first-line treatment option in combination with FOLFOX (fluorouracil, folinic acid and oxaliplatin) or FOLFIRI (fluorouracil, folinic acid and irinotecan). It may also be used in combination with irinotecan in patients refractory to irinotecan-based chemotherapy.
Dosage is based on the patient’s body surface area (milligram per square meter, mg/m2), and 400 mg/m2 is the recommended loading dose for slow infusion over two hours, at a maximum infusion rate of 5 mg/minute. A maintenance dose can be administered weekly at 250 mg/m2 over one hour, with a maximum infusion rate of 10 mg/minute. Treatment can continue until the disease has progressed, or toxicity levels become unacceptable.
Contraindications and precautions
Special precaution should be taken for patients with:
- A history of
- Cardiovascular diseases such as coronary artery disease, heart failure or arrhythmias
- Tick bites
- Keratitis, ulcerative keratitis or dry eyes
- Pre-existing cardio-pulmonary disease
- Red meat allergy
- Predisposition to, history of recurring, or chronic infections
- Positive test results for IgE antibodies
Side effects
The common side effects of cetuximab treatment include:
- Mild to severe allergic reactions
- Skin reactions such as acne, rash, dry skin, hair growth, itching, and nail changes
- Dehydration
- Loss of appetite and weight loss
- Diarrhea
- Nausea or feeling sick
- Tiredness, lethargy or fatigue
Type of treatment
Cetuximab is a monoclonal antibody produced using recombinant DNA technology and used in immunotherapy.
Treatment mechanism
Cetuximab targets the epidermal growth factor receptor (EGFR) present on the surface of cancer cells.
Cetuximab specifically binds to the EGFR, blocking the signal transduction pathway and inhibiting cancer cell growth. The EGFR is a transmembrane receptor tyrosine kinase that plays a critical role in cell proliferation, differentiation, and survival. It is overexpressed in many cancer types, including colorectal cancer, and is associated with poor prognosis and resistance to chemotherapy.
Cetuximab binds to the extracellular domain of EGFR, preventing the activation of downstream signaling pathways that promote cancer cell growth, survival, and invasion. The drug also induces antibody-dependent cellular cytotoxicity (ADCC), in which immune cells such as natural killer (NK) cells and macrophages recognize and destroy cancer cells coated with cetuximab. ADCC enhances the efficacy of cetuximab and may explain why some patients with low EGFR expression still respond to the drug.
Cetuximab has been shown to improve overall survival, progression-free survival, and response rates in patients with advanced colorectal cancer when used alone or in combination with chemotherapy. However, not all patients respond to cetuximab, and resistance to the drug is a major clinical problem. Several mechanisms of resistance have been identified, including mutations in KRAS and other downstream effectors of the EGFR signaling pathway, as well as upregulation of alternative receptor tyrosine kinases.