Associations between early loss of skeletal muscle and osimertinib trough concentrations in patients with advanced EGFR-mutated NSCLC

INTRODUCTION: This study explores the associations between computed tomography (CT)-derived changes in body composition during the first three months of osimertinib monotherapy, systemic osimertinib exposure, and treatment outcomes in patients with advanced EGFR+ NSCLC. MATERIALS AND METHODS: were estimated using linear mixed-effects modeling, while progression-free survival (PFS) and overall survival (OS) were evaluated using Cox proportional hazards models. RESULTS: and TP53 mutation status. CONCLUSION: Early loss of SMI was not associated with osimertinib exposure, yet an independent predictor of shorter OS. Future research should explore whether nutritional interventions to preserve muscle mass improve osimertinib effectiveness.