cetuximab
Erbitux (cetuximab) is a chimeric antibody that blocks the epidermal growth factor receptor (EGFR), a growth switch many cancers lean on. With chemotherapy or radiation, it is used in RAS wild-type metastatic colorectal cancer and squamous cell carcinoma of the head and neck.
This page is based on FDA prescribing information and the EMA medicine record for cetuximab, cross-checked with DailyMed and the National Cancer Institute dictionary; the mechanism is explained in plain language, and analogies are used only where they stay accurate.
How it works
Explains what the medicine does in the body, not dosing, side effects, or safety.
An analogy
EGFR is a doorbell that cancer cells keep pressing to tell themselves to grow. Cetuximab is a cover plate screwed over the button - growth factors can press all they want, but the bell never rings, and the cell stops getting instructions to multiply.
In simple terms
Many cancers display large numbers of EGFR molecules on their surface, and growth signals arriving through them drive the tumour to grow and resist treatment. Cetuximab binds the outside of EGFR and blocks those signals. It also flags the cancer cells for immune attack. Combined with chemotherapy or radiation, this slows tumour growth and improves outcomes in selected colorectal and head-and-neck cancers.
In depth
Cetuximab is a chimeric IgG1 monoclonal antibody that binds the extracellular domain of EGFR, preventing ligand-induced receptor activation and dimerisation and promoting receptor internalisation. It inhibits downstream RAS-MAPK and PI3K-AKT signalling, inducing apoptosis and reducing angiogenesis, and engages Fc-gamma receptors for antibody-dependent cellular cytotoxicity. Benefit in colorectal cancer is restricted to RAS wild-type tumours, because activating RAS mutations bypass EGFR blockade.
See it in motion
A schematic animation of the mechanism — simplified for clarity, not drawn to scale.
EGFR is a doorbell
- Many cancers display large numbers of EGFR molecules on their surface, and growth signals arriving through them drive the tumour to grow and resist treatment.
- Cetuximab binds the outside of EGFR and blocks those signals.
- It inhibits downstream RAS-MAPK and PI3K-AKT signalling, inducing apoptosis and reducing angiogenesis, and engages Fc-gamma receptors for antibody-dependent cellular cytotoxicity.
- It also flags the cancer cells for immune attack.
Target: Epidermal growth factor receptor (EGFR)
A cell-surface receptor that, when activated by growth factors, tells cells to divide and survive; many colorectal and head-and-neck cancers overuse this switch.
Approved uses
Approved uses differ by country and change over time. Always follow your local prescribing information.
Approved uses in United States
FDA- With radiation therapy, for the initial treatment of locally or regionally advanced squamous cell carcinoma of the head and neck
- With platinum-based therapy and fluorouracil, for first-line treatment of recurrent locoregional or metastatic squamous cell carcinoma of the head and neck
- As a single agent, for recurrent or metastatic squamous cell carcinoma of the head and neck after prior platinum-based therapy has failed
- For K-Ras wild-type, EGFR-expressing metastatic colorectal cancer, with FOLFIRI as first-line treatment, with irinotecan in patients refractory to irinotecan-based chemotherapy, or as a single agent after failure of oxaliplatin- and irinotecan-based therapy
Approved uses in European Union
EMA- For EGFR-expressing, RAS wild-type metastatic colorectal cancer, in combination with irinotecan-based chemotherapy, in first-line in combination with FOLFOX, or as a single agent in patients who have failed oxaliplatin- and irinotecan-based therapy and are intolerant to irinotecan
Official sources
The statements on this page trace back to these records.
- Erbitux (cetuximab) — Summary of product characteristics and package leaflet, English version
European Medicines Agency
- DailyMed: Erbitux (cetuximab) label
DailyMed, U.S. National Library of Medicine
- U.S. Food and Drug Administration: cetuximab prescribing information
U.S. Food and Drug Administration
- National Cancer Institute: cetuximab
National Cancer Institute
This page explains how the medicine works — it isn’t the patient leaflet. For anything that applies to you, read the leaflet that came with your medicine or ask your pharmacist.
MedUnfold provides educational content and is not medical advice. Always follow your local prescribing information and healthcare professional.