Management of cetuximab-induced skin toxicity with the prophylactic use of topical vitamin K1 cream

Cetuximab is an immunoglobulin G1 monoclonal antibody that binds to the extracellular domain of the epidermal growth factor receptor (EGFR) blocking ligand-induced auto-phosphorylation and subsequent receptor mediated signalling.1,2 Cetuximab in combination with chemotherapy is effective in the treatment of EGFR-expressing tumors including metastatic colorectal cancer (mCRC).2,3 EGFR is strongly expressed in the keratinocytes, cells of eccrine and sebacceous glands and in the epithelium of hair follicles, and is important for normal skin development and function.4 Blocking cutaneous EGFR signalling with EGFR inhibitors leads to a spectrum of skin reactions which occur in ≥80% of patients, the most common being acneiform rash which occurs most frequently on the head and neck regions and on the trunk. Other less frequent reactions include, pruritus, dry skin, desquamation, hypertrichosis, and paronychia.1,2 Approximately 15% of cutaneous reactions are severe (≥ grade 3; US National Cancer Institute– Common Toxicity Criteria)5, causing cetuximab therapy to be interrupted.6 We have investigated the prophylactic treatment of patients with a topically applied skin cream containing urea and 0.1% vitamin K1 (Renconval K1®) during cetuximab therapy. The aim of the study was to continue cetuximab without treatment delays or dose reductions, which may impact on tumour response rates.7 Four patients with mCRC receiving first-line cetuximab in combination with chemotherapy, had applied vitamin K1 cream facially twice daily for 8 weeks from the first infusion of cetuximab. Patients were screened weekly