cetuximab: clinical use

Prescribing considerations

• Confirm validated RAS status before use in metastatic colorectal cancer; do not treat RAS-mutated or unknown-status disease.
• Confirm BRAF V600E status before combining with encorafenib.
• Assess previous severe hypersensitivity and ask about red-meat or tick-bite allergy, which may indicate increased anaphylaxis risk.
• Consider performance status, cardiopulmonary disease, baseline organ function and accompanying treatment toxicities.
• Record the product name and batch number for traceability.

Contraindications and cautions

• Known severe hypersensitivity reaction to cetuximab.
• Use with oxaliplatin-containing chemotherapy in mutant-RAS metastatic colorectal cancer or when RAS status is unknown.
• Any contraindication applying to accompanying chemotherapy or radiotherapy.

Monitoring

• Observe closely during infusion and afterwards, with resuscitation facilities available.
• Check magnesium, calcium and potassium before treatment and periodically; replace electrolytes when appropriate.
• Monitor blood counts and infection risk closely with platinum-based chemotherapy.
• Assess skin and nail toxicity, including secondary bacterial infection.
• Investigate new dyspnoea, cough or fever promptly for interstitial lung disease.
• Refer acute or worsening eye pain, redness, light sensitivity or blurred vision promptly for ophthalmic assessment.
• Review cardiovascular risk and symptoms, particularly with fluoropyrimidines.

Clinical pharmacology

Cetuximab is a chimeric IgG1 monoclonal antibody that binds EGFR, blocks ligand-driven signalling, promotes receptor internalisation and supports antibody-dependent cellular cytotoxicity. It is degraded to peptides and amino acids rather than undergoing conventional hepatic metabolism.

Formulation and product differences

• The selected product is a colourless, preservative-free solution for intravenous infusion in single-use vials.
• It may be administered using a gravity drip, infusion pump or syringe pump through a separate line.
• It must not be mixed with other medicines and is refrigerated before use.

Solution for infusion

Route: Intravenous

Strengths: 5 mg/mL