Key points
- Cetuximab is an antibody that sticks to the EGFR growth receptor on cancer cells and cuts off the growth signal [1].
- It is used for head and neck cancer, with radiotherapy or chemotherapy or on its own [1, 2, 3].
- In colorectal cancer that has spread, it only works when a genetic test of the tumour shows a normal RAS gene, or together with another drug in tumours with a BRAF change; so a genetic test of the tumour is needed before starting [1, 4, 5].
- The most common side effects: acne-like spots, itching and nail changes, headache, diarrhoea and infection [1].
- The main risk is a severe reaction during the infusion and, rarely, cardiac arrest in head and neck cancer patients; this is why the infusion is given under close supervision [1].
What is this drug and how does it work?
For physicians
Cetuximab (brand name Erbitux) is a chimeric (part human, part mouse) IgG1 monoclonal antibody that binds specifically to the extracellular domain of the epidermal growth factor receptor (EGFR) [1]. EGFR is present in many normal tissues, including skin and hair follicles, and in many cancers such as head and neck, colon and rectal cancer [1].
By occupying the receptor, cetuximab prevents binding of epidermal growth factor (EGF) and related ligands and blocks activation of receptor-associated kinases; in laboratory and animal studies this inhibited cell growth, induced apoptosis and reduced VEGF production [1]. In vitro, cetuximab can also mediate antibody-dependent cellular cytotoxicity (ADCC) against tumour cells [1].
If the tumour has an activating RAS mutation, the mutant RAS protein stays permanently switched on regardless of EGFR [1]; this is why cetuximab has shown no benefit in RAS-mutant colorectal cancer and is not given [1]. In BRAF-mutant colorectal cancer, EGFR-mediated reactivation of the MAPK pathway is one mechanism of resistance to BRAF inhibitors, and cetuximab with encorafenib had greater antitumour activity in animal models than either alone [1].
Which cancers is it used for?
According to the FDA label, cetuximab is used in two groups of cancer: squamous cell carcinoma of the head and neck and metastatic colorectal cancer [1]. In colorectal cancer, patient selection depends on tumour testing (RAS status or a BRAF V600E mutation by an approved test), and cetuximab is not indicated for RAS-mutant tumours or tumours of unknown RAS status [1]. Approvals may differ between countries, and not every patient with these cancers is a candidate for this drug.
Your doctor may prescribe this drug for:
- Squamous cell cancer of the head and neck [1]
- Colorectal cancer that has spread, with wild-type K-Ras and EGFR expression [1]
- Colorectal cancer that has spread, with a BRAF V600E mutation [1, 6]
Whether it suits you depends on the type and stage of your cancer and your test results. Details of each use are in the section for doctors.
For physicians
| Cancer | Conditions of use |
|---|---|
| Squamous cell carcinoma of the head and neck | With radiotherapy, initial treatment of locally or regionally advanced disease [1] |
| Squamous cell carcinoma of the head and neck | First line for recurrent locoregional or metastatic disease, with platinum and fluorouracil chemotherapy [1] |
| Squamous cell carcinoma of the head and neck | Monotherapy for recurrent or metastatic disease after failure of platinum-based therapy [1] |
| Metastatic colorectal cancer, K-Ras wild type and EGFR-expressing | First line with FOLFIRI (irinotecan, fluorouracil, leucovorin) [1] |
| Metastatic colorectal cancer, K-Ras wild type and EGFR-expressing | With irinotecan when refractory to irinotecan-based chemotherapy; or monotherapy after failure of oxaliplatin and irinotecan or intolerance of irinotecan [1] |
| Metastatic colorectal cancer with a BRAF V600E mutation | With encorafenib, after prior therapy [1] |
| Metastatic colorectal cancer with a BRAF V600E mutation | With encorafenib and fluorouracil-based chemotherapy; this use is in the encorafenib (Braftovi) label [6] |
Cetuximab is not indicated for head and neck cancer in combination with radiotherapy and cisplatin; in a 940-patient trial, adding it to this combination did not improve progression-free survival and increased grade 3 and 4 adverse reactions [1].
| Cancer | Key evidence |
|---|---|
| Squamous cell carcinoma of the head and neck | Bonner trial: median locoregional control 24.4 vs 14.9 months and median overall survival 49.0 vs 29.3 months compared with radiotherapy alone [1, 2] |
| Squamous cell carcinoma of the head and neck | EXTREME trial: median overall survival 10.1 vs 7.4 months (HR 0.80) [1, 3] |
| Squamous cell carcinoma of the head and neck | Single-arm study EMR 62202-016: objective response rate 13% [1] |
| Metastatic colorectal cancer, K-Ras wild type and EGFR-expressing | CRYSTAL trial, K-Ras wild-type subgroup: median progression-free survival 9.5 vs 8.1 months and median overall survival 23.5 vs 19.5 months [1, 4] |
| Metastatic colorectal cancer, K-Ras wild type and EGFR-expressing | CA225-025 study, K-Ras wild-type subgroup: median overall survival 8.6 vs 5.0 months compared with best supportive care; BOND trial for the combination with irinotecan [1] |
| Metastatic colorectal cancer with a BRAF V600E mutation | BEACON CRC trial: median overall survival 8.4 vs 5.4 months (HR 0.60) [1, 5] |
| Metastatic colorectal cancer with a BRAF V600E mutation | BREAKWATER trial (encorafenib + cetuximab + mFOLFOX6): median overall survival 30.3 vs 15.1 months at the interim analysis (HR 0.49) [7] |
A different cetuximab product was used in the EXTREME and CRYSTAL trials [1].
Place alongside other treatments: in NRG Oncology RTOG 1016 in HPV-positive oropharyngeal cancer, radiotherapy with cetuximab gave lower 5-year overall survival than radiotherapy with cisplatin (77.9% vs 84.6%), and non-inferiority was not shown [8]. In KEYNOTE-048 in recurrent or metastatic head and neck cancer, pembrolizumab (Keytruda) with platinum and fluorouracil gave longer overall survival in the total population than the EXTREME regimen (cetuximab + platinum + fluorouracil) (13.0 vs 10.7 months; HR 0.77) [9].
How it is taken and dosing
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Treatment regimens and doses: index5 regimens
Cetuximab is given as an intravenous infusion (a drip into a vein) at a treatment centre; the first dose over 120 minutes and later weekly doses over 60 minutes, or on the every-2-weeks schedule, each dose over 120 minutes [1]. An intravenous antihistamine is given before the first infusion (and later ones if needed) [1].
- You stay under observation for at least 1 hour after each infusion, because a reaction can happen during the infusion or several hours after it ends [1].
- With radiotherapy, cetuximab starts one week before radiotherapy and is repeated every week during the course of radiotherapy (6 to 7 weeks); otherwise it continues until the disease progresses or side effects cannot be tolerated [1].
- In colorectal cancer, RAS status (or a BRAF V600E mutation) is checked on a tumour sample before starting [1].
- During treatment and for at least 8 weeks after it ends, blood magnesium, calcium and potassium are checked every week [1].
- If you have had tick bites or an allergy to red meat, tell your doctor; these people may be at higher risk of a severe allergic reaction, and your doctor may consider an alpha-gal antibody test before starting [1].
- Be sure to tell your treatment team about any history of coronary heart disease, heart failure or heart rhythm problems [1].
- Patient selection (colorectal): RAS wild type with EGFR expression, or a BRAF V600E mutation by an approved test [1].
- Before starting: a history of tick bites, red meat allergy or anti-alpha-gal IgE increases the risk of anaphylaxis; consider an alpha-gal IgE test (a negative result does not exclude the risk). In head and neck cancer with a history of coronary artery disease, heart failure or arrhythmia, use the combination with radiotherapy or platinum and fluorouracil with caution [1].
- Premedication: an IV H1 antagonist 30 to 60 minutes before the first dose and later doses as needed. About 90% of severe reactions occurred with the first dose despite premedication [1].
- Administration: by infusion pump or syringe pump, never as an IV push or bolus; maximum 10 mg per minute; a low protein-binding 0.22 µm in-line filter; do not dilute or shake the solution. Monitor for at least 1 hour after each infusion in a setting with resuscitation facilities [1].
- Infusion reaction: grade 1–2: reduce the rate by 50%; grade 3–4: stop immediately and permanently [1].
- Grade 3–4 dermatological or infectious toxicity: delay 1 to 2 weeks; if improved, 250 mg/m² after the first occurrence, 200 after the second and 150 after the third; no improvement or a fourth occurrence: discontinue [1].
- Acute or worsening pulmonary symptoms: delay 1 to 2 weeks and resume at the same dose if improved; no improvement within 2 weeks or confirmed ILD: discontinue [1].
- Monitoring: magnesium, potassium and calcium during treatment and for at least 8 weeks after, with replacement as needed (cardiopulmonary arrest and sudden death have been reported in head and neck cancer) [1].
For physicians
Standard dosing and regimens (FDA label)
Cetuximab + radiotherapy
Locally or regionally advanced squamous cell carcinoma of the head and neck, initial treatmentCycle length: Weekly
Locally or regionally advanced squamous cell carcinoma of the head and neck, initial treatment
Before prescribing: Prescribing notes| Drug | Dose | Route | Schedule |
|---|---|---|---|
| One week before radiotherapy | |||
| Cetuximab | 400 mg/m² | IV, 120 minutes | Once |
| During radiotherapy | |||
| Cetuximab | 250 mg/m² | IV, 60 minutes | Every week |
Complete the infusion 1 hour before radiotherapy [1].
Cetuximab ± platinum and fluorouracil
Recurrent locoregional or metastatic head and neck cancer: first line with platinum and fluorouracil; or monotherapy after platinum failure
Recurrent locoregional or metastatic head and neck cancer: first line with platinum and fluorouracil; or monotherapy after platinum failure
Before prescribing: Prescribing notes| Drug | Dose | Route | Schedule |
|---|---|---|---|
| Weekly: first dose | |||
| Cetuximab | 400 mg/m² | IV, 120 minutes | |
| Weekly: later doses | |||
| Cetuximab | 250 mg/m² | IV, 60 minutes | Every week |
| Or every 2 weeks | |||
| Cetuximab | 500 mg/m² (first and later doses) | IV, 120 minutes | Every 2 weeks |
Complete the infusion 1 hour before chemotherapy; platinum and fluorouracil doses as per those drugs' labels [1].
Cetuximab ± FOLFIRI or irinotecan
RAS wild-type (K-Ras wild-type) EGFR-expressing metastatic colorectal cancer: first line with FOLFIRI; with irinotecan when refractory to irinotecan; monotherapy after failure of oxaliplatin and irinotecan or intolerance of irinotecan
RAS wild-type (K-Ras wild-type) EGFR-expressing metastatic colorectal cancer: first line with FOLFIRI; with irinotecan when refractory to irinotecan; monotherapy after failure of oxaliplatin and irinotecan or intolerance of irinotecan
Before prescribing: Prescribing notes| Drug | Dose | Route | Schedule |
|---|---|---|---|
| Weekly: first dose | |||
| Cetuximab | 400 mg/m² | IV, 120 minutes | |
| Weekly: later doses | |||
| Cetuximab | 250 mg/m² | IV, 60 minutes | Every week |
| Or every 2 weeks | |||
| Cetuximab | 500 mg/m² (first and later doses) | IV, 120 minutes | Every 2 weeks |
Complete the infusion 1 hour before irinotecan or FOLFIRI. Not indicated for RAS-mutant or unknown RAS status (more progression and deaths) [1].
Cetuximab + encorafenib
BRAF V600E-mutant metastatic colorectal cancer after prior therapyCycle length: Weekly
BRAF V600E-mutant metastatic colorectal cancer after prior therapy
Before prescribing: Prescribing notes| Drug | Dose | Route | Schedule |
|---|---|---|---|
| Weekly: first dose | |||
| Cetuximab | 400 mg/m² | IV, 120 minutes | |
| Weekly: later doses | |||
| Cetuximab | 250 mg/m² | IV, 60 minutes | Every week |
| Encorafenib | 300 mg (4 capsules of 75 mg) once daily | Oral, with or without food | Every day |
Cetuximab + encorafenib + mFOLFOX6 or FOLFIRI
BRAF V600E-mutant metastatic colorectal cancer (as per the encorafenib label)Each drug’s schedule in the table
BRAF V600E-mutant metastatic colorectal cancer (as per the encorafenib label)
Before prescribing: Prescribing notes| Drug | Dose | Route | Schedule |
|---|---|---|---|
| Cetuximab | 500 mg/m² | IV, 120 minutes | Every 2 weeks |
| Encorafenib | 300 mg once daily | Oral | Every day |
| mFOLFOX6 or FOLFIRI | As per the drug labels | IV | Every 2 weeks |
Doses follow the trial protocol, guideline or official drug label (source given in the notes of each regimen). Before prescribing, check blood counts, renal and hepatic function, drug interactions and the patient’s condition, and adjust the dose according to the drug label.
Side effects
The most common side effects:
For physicians
Across trials, the most common adverse reactions to cetuximab alone or with radiotherapy or chemotherapy (incidence 25% or more) were skin reactions (rash, pruritus and nail changes), headache, diarrhoea and infection [1]. Acneiform rash occurred in 82% of 1373 patients and was severe (grade 3 or 4) in 10%; it usually appears in the first two weeks of treatment and in most patients persisted more than 28 days after stopping the drug [1].
The frequency of adverse reactions (all grades) varies with the partner treatment:
- With radiotherapy in head and neck cancer (Bonner trial): acneiform rash 87%, weight loss 84%, asthenia 56%, nausea 49%, fever 29%, vomiting 29%, diarrhoea 19%, headache 19% and infusion reaction 15% [1].
- Monotherapy in colorectal cancer (CA225-025 study): rash/desquamation 95%, fatigue 91%, nausea 64%, dry skin 57%, constipation 53%, pruritus 47%, diarrhoea 42%, headache 38% and nail changes 31%; some of these (for example fatigue in 79%) were also seen with best supportive care alone [1].
- With FOLFIRI (CRYSTAL trial): acneiform rash 86%, diarrhoea 66%, neutropenia 49%, stomatitis 31% and paronychia 20% [1].
- With encorafenib (BEACON CRC trial): fatigue 51%, nausea 34%, diarrhoea 33%, acneiform dermatitis 32% and abdominal pain 30% [1].
Serious side effects
These are less common but serious; tell your team early if you notice any sign of them:
- A reaction during the infusion: mostly with the first infusion; wheezing, a hoarse voice, shortness of breath, dizziness or fainting. Tell the nurse straight away [1].
- Heart problems and cardiac arrest (rare), especially in head and neck cancer with radiotherapy or chemotherapy [1].
- Skin infection or severe spots, blisters or widespread peeling [1].
- Low magnesium: muscle cramps, weakness or palpitations; regular blood tests are needed [1].
- Lung inflammation (a new cough or shortness of breath, rare) and harm to an unborn baby [1].
For physicians
Boxed warning: cetuximab can cause serious and fatal infusion reactions, and cardiopulmonary arrest or sudden death has occurred in patients with head and neck cancer treated with radiotherapy or with platinum and fluorouracil [1].
- Infusion reactions: in 8.4% of 1373 patients (severe in 2.2%); about 90% of severe reactions occurred with the first infusion despite antihistamine premedication. Symptoms include rapid airway obstruction (wheezing, hoarseness), hypotension, shock, loss of consciousness, myocardial infarction or cardiac arrest [1].
- Cardiopulmonary arrest: in 2% of 208 patients receiving radiotherapy with cetuximab in the Bonner trial; in EXTREME, fatal cardiac disorders or sudden death were reported in 3% of 219 patients [1].
- Pulmonary toxicity (interstitial lung disease, ILD): in less than 0.5% of 1570 patients, including one fatal case [1].
- Dermatological toxicity: besides rash, dry and fissured skin, paronychia and secondary infections (such as staphylococcal sepsis, abscess, cellulitis, blepharitis, conjunctivitis and keratitis); life-threatening and fatal bullous mucocutaneous disease has also been reported [1].
- Hypomagnesaemia and other electrolyte disturbances: hypomagnesaemia in 55% of 365 patients (grade 3 and 4 in 6% to 17%); it may occur days to months after starting treatment [1].
- Embryo-fetal toxicity: based on animal studies and mechanism of action, cetuximab can harm a fetus [1].
When should I call my doctor?
Contact your treatment team straight away if you have any of these symptoms:
- Fever, chills or breathing problems during the infusion or even several hours after it (a delayed infusion reaction) [1]
- A new or worsening cough, chest pain or shortness of breath [1]
- Acne-like spots, itchy, dry, scaly or cracked skin, inflammation, infection or swelling around the nails, or nails falling off [1]
- Red, inflamed eyes or eyelids, or reduced vision [1]
- Pregnancy or a possible pregnancy [1]
In severe cases (for example severe shortness of breath, reduced consciousness or severe chest pain), call your local emergency number.
Interactions, pregnancy and precautions
- Drug interactions: in studies, no pharmacokinetic interaction was seen between cetuximab and irinotecan, cisplatin or carboplatin, and with encorafenib there was no clinically important difference in the levels of either drug [1]. Even so, give your treatment team a list of all your medicines and supplements.
- Sun: limit sun exposure during treatment and for 2 months after the last dose [1].
- Pregnancy and contraception: pregnancy status is checked before starting; women who could become pregnant should use effective contraception during treatment and for 2 months after the last dose [1].
- Breastfeeding: do not breastfeed during treatment and for 2 months after the last dose [1].
- Fertility: based on animal studies, cetuximab may reduce female fertility [1].
- Vaccines: the FDA label gives no specific advice about vaccines; talk to your treatment team before any vaccination.
- Missing a dose: because the drug is given at a treatment centre, if you miss an appointment, arrange a new time with your treatment team as soon as possible.
Frequently asked questions
Is cetuximab chemotherapy?
No. Cetuximab is a monoclonal antibody, a targeted treatment that binds the EGFR receptor; in many cases, though, it is given with chemotherapy or radiotherapy [1].
Why is a genetic test of the tumour needed before starting in colorectal cancer?
In patients whose tumour has a RAS mutation, cetuximab has given no clinical benefit and only caused side effects; so the FDA label stresses that RAS mutation status must be confirmed in a tumour sample before starting [1].
Does cetuximab cause hair loss?
Hair loss is not a main side effect of this drug; in a large study, hair loss was slightly more common with cetuximab and chemotherapy than with chemotherapy alone, but most patients did not have it [1]. On the other hand, excess hair growth (hypertrichosis) is also listed among the skin side effects [1].
When do the skin spots appear and how long do they last?
How long does cetuximab treatment last?
With radiotherapy, the drug is given during the course of radiotherapy (6 to 7 weeks); in other uses it continues until the disease progresses or side effects cannot be tolerated [1].
Scientific evidence
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Key studies
3 itemsRadiotherapy plus cetuximab or cisplatin in human papillomavirus-positive oropharyngeal cancer (NRG Oncology RTOG 1016): a randomised, multicentre, non-inferiority trial
Encorafenib, Cetuximab, and mFOLFOX6 in BRAF-Mutated Colorectal Cancer
Pembrolizumab alone or with chemotherapy versus cetuximab with chemotherapy for recurrent or metastatic squamous cell carcinoma of the head and neck (KEYNOTE-048): a randomised, open-label, phase 3 study
Related cancer types
Treatment regimens (physicians)
References
9 referencesShow all references, 7 with a study cardClose the reference list
Numbers in the text, such as [1], refer to these sources. Sources with a “Study card” button are summarised in the site’s evidence library.
- 1ERBITUX (cetuximab) injection, for intravenous use: Prescribing Information
- 2Radiotherapy plus Cetuximab for Squamous-Cell Carcinoma of the Head and Neck
- 3Platinum-Based Chemotherapy plus Cetuximab in Head and Neck Cancer
- 4Cetuximab and Chemotherapy as Initial Treatment for Metastatic Colorectal Cancer
- 5Encorafenib, Binimetinib, and Cetuximab in BRAF V600E–Mutated Colorectal Cancer
- 6
- 7Encorafenib, Cetuximab, and mFOLFOX6 in BRAF-Mutated Colorectal Cancer
- 8Radiotherapy plus cetuximab or cisplatin in human papillomavirus-positive oropharyngeal cancer (NRG Oncology RTOG 1016): a randomised, multicentre, non-inferiority trial
- 9Pembrolizumab alone or with chemotherapy versus cetuximab with chemotherapy for recurrent or metastatic squamous cell carcinoma of the head and neck (KEYNOTE-048): a randomised, open-label, phase 3 study
This page is based on reputable scientific sources and was last updated on 27 October 2026. The content of this website is for educational and informational purposes only and does not replace consultation, diagnosis or treatment by a specialist physician. Consult your treating physician about any treatment decision.
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