360P ELIOS: A multicentre, molecular profiling study of patients (pts) with epidermal growth factor receptor-mutated (EGFRm) advanced NSCLC treated with first-line (1L) osimertinib

Osimertinib – a 3rd-generation EGFR-TKI – is the preferred 1L treatment for EGFRm advanced NSCLC; however, pts can eventually develop progressive disease (PD). ELIOS (NCT03239340) characterised resistance mechanisms to 1L osimertinib. To our knowledge, this is the first prospective study with a primary objective comparing paired baseline and post-PD tumour tissue biopsies.