Successful treatment with osimertinib for leptomeningeal carcinomatosis from NSCLC with the EGFR T790M mutation

Abstract

Abstract Osimertinib is a third-generation tyrosine kinase inhibitor (TKI) of the epidermal growth factor receptor (EGFR) that has been approved for the treatment of metastatic non-small cell lung cancer (NSCLC) with EGFR mutation, and positive for the secondary T790M mutation of EGFR. In a preclinical study, it also showed efficacy against leptomeningeal carcinomatosis (LMC) derived from NSCLC resistant to first-generation and second-generation EGFR-TKIs. We report the case of a patient aged 55 years with symptomatic LMC derived from NSCLC. We detected T790M mutation of EGFR by liquid biopsy with blood sample. He showed a clinical and radiographic response to osimertinib.