ERBITUX SOLUTION FOR INFUSION

Indications

• Metastatic colorectal cancer (in combination with chemotherapy)
• Head and neck squamous cell carcinoma (HNSCC)
• Locally advanced squamous cell carcinoma of the head and neck
• Epidermal growth factor receptor (EGFR) expressing malignancies

Dosage

Adults: The recommended dosage of cetuximab for adults is an initial dose of

Mechanism of action

Cetuximab binds specifically to the extracellular domain of the epidermal growth factor receptor (EGFR), inhibiting its activation by natural ligands such as EGF and transforming growth factor-alpha (TGF-alpha). This blockade prevents receptor dimerization and subsequent activation of intracellular signaling pathways, including the RAS-RAF-MAPK and PI3K-AKT pathways, which are critical for cell proliferation and survival. The inhibition of these pathways leads to reduced tumor cell growth and may enhance the effectiveness of chemotherapy and radiation.

Pharmacodynamics

The pharmacodynamics of cetuximab involve its ability to inhibit tumor growth by blocking EGFR signaling. This results in decreased cell proliferation, increased apoptosis, and potential enhancement of immune-mediated antitumor activity. Cetuximab has been shown to be effective in tumors that express high levels of EGFR, but its efficacy is diminished in patients with RAS mutations, particularly in colorectal cancer.

Pharmacokinetics

Cetuximab is administered via intravenous infusion, and its pharmacokinetics can be impacted by the patient's body weight and the presence of anti-cetuximab antibodies. The half-life of cetuximab is approximately 112 hours after the first dose and may increase with subsequent doses due to saturation of binding sites. The drug is primarily eliminated via the reticuloendothelial system, and its clearance may be reduced in patients with liver dysfunction.

Adverse effects

• Infusion-related reactions
• Nausea
• Vomiting
• Skin eruption
• Severe cutaneous adverse reactions
• Embolism and thrombosis
• Interstitial lung disease
• Meningitis
• Aseptic superinfection of skin lesions
• Keratitis
• Ulcerative keratitis

Interactions

• Monoclonal antibodies may have additive effects when used in combination

Precautions

• Resuscitation facilities should be available during treatment
• Monitor for signs and symptoms of infusion-related side effects
• Patients presenting with acute or worsening signs suggestive of keratitis should be referred to an ophthalmology specialist
• Treatment should be interrupted or discontinued if ulcerative keratitis is diagnosed
• A patient alert card should be provided to patients

Pregnancy

Manufacturer advises discontinuation of breastfeeding during treatment and for at least 4 months after stopping. No information available on risks in pregnancy.

Breast-feeding

Manufacturer advises discontinuation of breastfeeding during treatment and for at least 4 months after stopping.

Storage

Store in a refrigerator at 2 to 8 degrees Celsius.

Formulations

• Solution for infusion: Libtayo (Sanofi Genzyme) - 50 mg per 1 ml and 350 mg/7 ml concentrate for solution