Skin Rash Can Be a Useful Marker for Afatinib Efficacy.

BACKGROUND/AIM: Although afatinib has a strong efficacy, it can be toxic; hence, we aimed to determine markers of response to afatinib in order to assess prognosis. PATIENTS AND METHODS: Information on clinical background, therapeutic effects, and adverse events was collected retrospectively at one Institution from patients treated with afatinib as initial epidermal growth factor receptor (EGFR)-tyrosine kinase inhibitor (TKI). We examined the relationship between different adverse events and their effects on prognosis. RESULTS: Afatinib was used in 32 patients as the initial EGFR-TKI. Adverse events of grade 3 or higher including diarrhoea (12.5%), paronychia (6.3%), and stomatitis (3.1%) were experienced by patients. The median progression-free survival (PFS) was 15.4 months. A relationship between skin rash severity and PFS was observed. CONCLUSION: Grade 2 or higher skin rash might be a marker for long-term efficacy of afatinib when administered as a first-line treatment.