Osimertinib activates TFEB to trigger hepatocyte cytoplasmic vacuolation-associated cell death.

Osimertinib is a first-line treatment for advanced non-small cell lung cancer with epidermal growth factor receptor (EGFR)-sensitive mutations; however, the severe hepatotoxicity of osimertinib is a challenge that has attracted attention. In this study, we found that osimertinib directly caused hepatocyte damage, with cells showing morphological features of vacuolization after treatment. Using transmission electron microscopy and other analytical techniques, we found that excessive activation of the autophagy-lysosome pathway was the main cause of cell vacuolation. Mechanistically, osimertinib causes dephosphorylation of transcription factor EB (TFEB), leading to its translocation into the nucleus to exert transcriptional regulatory functions. TFEB in the nucleus induces autophagy and lysosome biogenesis, thereby causing excessive activation of the autophagy-lysosome pathway subsequently leading to vacuolation-associated cell death. Through this study, we have identified S-adenosyl-L-methionine as a clinical hepatoprotective agent that could mitigate osimertinib-induced hepatocyte damage by inhibiting TFEB activation. Collectively, our findings not only lay the groundwork for addressing the clinical challenges posed by osimertinib hepatotoxicity but also broaden our understanding of drug-induced hepatocyte injury, thereby offering a novel research pathway for the study of drug-induced liver injury.