Standard dose osimertinib for erlotinib refractory T790M-negative EGFR-mutant non-small cell lung cancer with leptomeningeal disease

Abstract

Background: Leptomeningeal spread in non-small cell lung cancer (NSCLC) patients with epidermal growth factor receptor (EGFR) mutations who experience disease progression on TKIs portends a poor prognosis. Mutation profiling of tumour DNA in cerebrospinal fluid (CSF) samples can be used to determine the presence of the EGFR T790M resistance mutation, indicating that osimertinib, a CNS-penetrating 3rd generation TKI may be efficacious. Methods: Eight patients on EGFR TKIs who progressed with cytology-proven leptomeningeal disease at our institution were studied. EGFR mutations were profiled in CSF using droplet digital PCR (ddPCR) and compared to matched plasma samples. Clinical characteristi..