Osimertinib and Etoposide as First-Line Treatment in Osimertinib-Resistant Advanced EGFR-Mutant NSCLC

Osimertinib, though a standard first-line treatment for EGFR-mutant advanced NSCLC, shows primary resistance in 10-30% of patients, leading to disease progression within 3-4 months. This resistance is linked to co-mutations in genes like TP53, RB1, and PIK3CA, among others. Studies indicate that Topo II inhibitor Etoposide (VP-16) can reduce cell survival, enhance DNA damage, and delay resistance in Osimertinib-resistant cells, suggesting a potential combination therapy to manage resistance.This study is a single-center, prospective, single-arm study evaluating the efficacy and safety of osimertinib combined with etoposide as a first-line treatment in patients with osimertinib-resistant or -insensitive advanced non-small cell lung cancer (NSCLC). The study focuses on patients with advanced NSCLC (stage IIIB or IV) with EGFR-sensitive mutations who developed slow resistance to osimertinib and for whom secondary biopsy after resistance did not identify any therapeutic targets.