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Cetuximab is an epidermal growth factor receptor (EGFR) inhibitor with the following FDA-approved indications: colorectal cancer, metastatic, KRAS wild-type (without mutation), and head and neck cancer (squamous cell). Non-FDA-approved uses include colorectal cancer, non-small cell lung cancer (NSCLC), EGFR-expressing, advanced, and squamous cell skin cancer. This activity reviews the mechanism of action, adverse event profile, toxicity, dosing, pharmacodynamics, and monitoring of cetuximab, pertinent for members of the interprofessional team for the treatment of patients with malignancies for which it is indicated. Objectives: Identify the approved and non-approved indications for therapy with cetuximab. Outline the mechanism of action of cetuximab. Describe the adverse effects and monitoring for cetuximab. Summarize the importance of collaboration and communication among interprofessional team members to improve outcomes and treatment efficacy for patients receiving treatment with cetuximab. Access free multiple choice questions on this topic.

Cardiopulmonary arrest: Cardiopulmonary arrest and/or sudden death occurred in 2% of patients. Use with caution in patients with a history of coronary artery disease, heart failure, and arrhythmias. Infusion reactions: Serious infusion reactions occurred with the administration of cetuximab in approximately 3% of patients in clinical trials, with fatal outcomes reported in less than 1 in 1000. Immediately interrupt and permanently discontinue cetuximab infusion for serious infusion reactions. In most subjects with a hypersensitivity reaction to cetuximab, IgE antibodies against cetuximab were present in serum before therapy. The antibodies were specific for galactose alpha-1,3-galactose. The presence of this oligosaccharide is related to the production of cetuximab in a murine cell line. Anaphylaxis in response to cetuximab is a significant clinical problem in the Southeastern United States, with a grade 3/4 infusion reaction rate of 14%.[6] Dermatologic toxicity: An acne-like or maculopapular rash, a characteristic side effect of EGFR blockade, is due to the role of EGFR in maintaining the integrity of the skin. There are reports of acneiform rash in 76% to 88% of patients (severe in 1% to 17%), usually developing within the first two weeks of therapy, may require dose modification, generally resolved after discontinuation in most patients, although persisted beyond 28 days in some patients. The acneiform rash should have treatment with topical and/or oral antibiotics; topical corticosteroids are not recommended. Interstitial lung disease: use with caution in patients with preexisting lung disease. Electrolyte abnormality: Hypomagnesemia is common (may be severe). Because EGFR strongly expresses in the kidney, particularly in the ascending limb of the loop of Henle, where 70% of filtered magnesium gets reabsorbed, EGFR blockade may interfere with magnesium transport. Because symptoms may ameliorate rapidly with supplementation, when fatigue or hypocalcemia occurs during cetuximab therapy, serum magnesium levels should be measured, with repletion as necessary. The onset of electrolyte disturbance may occur within days to months after initiation of treatment; monitor magnesium, calcium, and potassium during treatment and for at least eight weeks after completion.[2]

Cetuximab is an inhibitor of epidermal growth factor receptor (EGFR) utilized for the treatment of several malignancies. Its administration and management require the effort of an interprofessional healthcare team. The drug is usually administered only by the oncologist, but a board-certified oncology pharmacist should play a role in dosing, administration, scheduling, and educating the patient on the potential adverse effects. Also, oncology nurses should be aware of the possible complications that can occur during the infusion and report these to the oncologist when encountered.[7][8][9] The team should monitor vital signs during infusion and observe the patient for at least 1-hour post-infusion. Patients developing dermatologic toxicities should be monitored for the development of complications. It is recommended to continue periodic monitoring of serum magnesium, calcium, and potassium over an interval consistent with the half-life (8 weeks); monitor closely (during and after treatment) for cetuximab plus radiation therapy, and obtain KRAS genotyping of tumor tissue in patients with colorectal cancer.[1][6] This type of interprofessional team approach is necessary to achieve optimal patient outcomes with cetuximab therapy. [Level 5]