Infusion-Related Reactions: If the patient experiences a mild or moderate infusion-related reaction, the infusion rate may be decreased. It is recommended to maintain this lower infusion rate in all subsequent infusions.
Severe infusion-related reactions have been reported in patients treated with cetuximab (see Adverse Reactions). Symptoms usually occurred during the 1st infusion and up to 1 hr after the end of infusion, but may occur after several hrs or with subsequent infusions. It is recommended to warn patients of the possibility of such a late onset and instruct them to contact their physician if symptoms of an infusion-related reaction occur. Occurrence of a severe infusion-related reaction requires immediate and permanent discontinuation of cetuximab therapy and may necessitate emergency treatment.
Special attention is recommended for patients with reduced performance status and preexisting cardiopulmonary disease.
Respiratory Disorders: Cases of interstitial lung disease have been reported, with the majority of patients from the japanese population. If interstitial lung disease is diagnosed, cetuximab must be discontinued and the patient be treated appropriately.
Skin Reactions: Skin reactions are very common and treatment interruption or discontinuation may be required. According to clinical practice guidelines, prophylactic use of oral tetracyclines (6-8 weeks) and topical application of 1% hydrocortisone cream with moisturiser should be considered. Medium to high-potency topical corticosteroids or oral tetracyclines have been used for the treatment of skin reactions. If a patient experiences a severe skin reaction [≥grade 3; US National Cancer Institute-Common Toxicity Criteria (NCI-CTC)], cetuximab therapy must be interrupted. Treatment may only be resumed if the reaction has resolved to grade 2 (see Adverse Reactions).
If the severe skin reaction occurred for the 1st time, treatment may be resumed without any change in dose level.
With the 2nd and 3rd occurrences of severe skin reactions, cetuximab therapy must again be interrupted. Treatment may only be resumed at a lower dose level (200 mg/m2 body surface area after the 2nd occurrence and 150 mg/m2 after the 3rd occurrence) if the reaction has resolved to grade 2.
If severe skin reactions occur for the 4th time or do not resolve to grade 2 during interruption of treatment, permanent discontinuation of cetuximab treatment is required.
Electrolyte Disturbances: Progressively decreasing serum magnesium levels occur frequently and may lead to severe hypomagnesaemia. Hypomagnesaemia is reversible following discontinuation of cetuximab. In addition, hypokalaemia may develop as a consequence of diarrhoea. Hypocalcaemia may also occur; the frequency of severe hypocalcaemia may be increased particularly when combined with platinum-based chemotherapy.
Determination of serum electrolyte levels is recommended prior to and periodically during cetuximab treatment. Electrolyte repletion is recommended, as appropriate.
Neutropenia and Related Infectious Complications: Patients who receive cetuximab in combination with platinum-based chemotherapy are at an increased risk for the occurrence of severe neutropenia, which may lead to subsequent infectious complications eg, febrile neutropenia, pneumonia or sepsis. Careful monitoring is recommended in such patients, in particular in those who experience skin lesions, mucositis or diarrhoea that may facilitate the occurrence of infections (see Adverse Reactions).
Cardiovascular Disorders: An increased frequency of severe and sometimes fatal cardiovascular events and treatment emergent deaths has been observed in the treatment of non-small cell lung cancer, squamous cell carcinoma of the head and neck and colorectal carcinoma. In some studies, association with age ≥65 years or performance status has been observed. When prescribing cetuximab, the cardiovascular and performance status of the patients and concomitant administration of cardiotoxic compounds eg, fluoropyrimidines should be taken into account.
Eye Disorders: Patients presenting with signs and symptoms suggestive of keratitis eg, acute or worsening: eye inﬂammation, lacrimation, light sensitivity, blurred vision, eye pain and/or red eye should be referred promptly to an ophthalmology specialist.
If a diagnosis of ulcerative keratitis is conﬁrmed, treatment with cetuximab should be interrupted or discontinued. If keratitis is diagnosed, the beneﬁts and risks of continuing treatment should be carefully considered.
Cetuximab should be used with caution in patients with a history of keratitis, ulcerative keratitis or severe dry eye. Contact lens use is also a risk factor for keratitis and ulceration.
Colorectal Cancer Patients with KRAS Mutated Tumours: Cetuximab should not be used in the treatment of colorectal cancer patients whose tumours have KRAS mutations or for whom KRAS tumour status is unknown. Results from clinical studies show a negative benefit-risk balance in tumours with KRAS mutations, in particular, in combination with continuous infusional 5-ﬂuorouracil/folinic acid plus oxaliplatin (see Pharmacology under Actions).
Special Populations: Only patients with adequate renal and hepatic function have been investigated to date (serum creatinine ≤1.5-fold, transaminases ≤5-fold and bilirubin ≤1.5-fold the upper limit of normal).
Cetuximab has not been studied in patients presenting with 1 or more of the following laboratory parameters: Haemoglobin <9 g/dL, leukocyte count <3000/mm3, absolute neutrophil count <1500/mm3 and platelet count <100,000/mm3.
There is limited experience in the use of cetuximab in combination with radiation therapy in colorectal cancer.
Effects on the Ability to Drive or Operate Machinery: No studies on the effects on the ability to drive and use machines have been performed. If patients experience treatment-related symptoms affecting their ability to concentrate and react, it is recommended that they do not drive or use machines until the effect subsides.
Use in pregnancy & lactation: The epidermal growth factor receptor (EGFR) is involved in foetal development. Limited observations in animals are indicative of a placental transfer of cetuximab and other IgG1 antibodies have been found to cross the placental barrier. Animal data revealed no evidence of teratogenicity. However, dependent on the dose, an increased incidence of abortion was observed (see Toxicology under Actions). Sufficient data from pregnant or lactating women are not available.
It is strongly recommended that Erbitux be given during pregnancy or to any woman not employing adequate contraception only if the potential benefit justifies a potential risk to the foetus.
It is recommended that women do not breastfeed during treatment with Erbitux and for 2 months after the last dose, because it is not known whether cetuximab is excreted in breast milk.
Use in children: The safety and effectiveness of cetuximab in paediatric patients <18 years have not been established.