Osimertinib‐related liver injury with successful osimertinib rechallenge: A case report

Osimertinib is approved as the first‐line treatment for advanced non‐small cell lung cancer patients with epidermal growth factor (EGFR) mutation and for patients who develop EGFR T790M mutation during EGFR tyrosine kinase inhibitor (TKI) treatment and disease progression. Asymptomatic elevation of aminotransferase levels is commonly observed during TKI treatment; however, significant hepatotoxicity is infrequent. Here, we report a patient with osimertinib‐related drug‐induced liver injury who was successfully managed with osimertinib rechallenge. We report a patient with osimertinib‐related drug‐induced liver injury, a serious but rare adverse event, who was successfully managed with osimertinib rechallenge. We revealed the trend of serum liver enzymes, bilirubin, and tumor marker before, during, and after osimertinib treatment and retreatment. Liver pathology test performed with the Hematoxylin and Eosin stain and the immunohistochemistry stain was also shown in this study.