Acquired EGFR L718V mutation mediates resistance to osimertinib in non-small cell lung cancer but retains sensitivity to afatinib

We reported that distinct resistance mechanisms could arise in different metastases within the same patient in response to EGFR blockade. We also demonstrated in vitro that EGFR L718V mutation mediates resistance to osimertinib, but retains sensitivity to afatinib. We evidenced that dynamic companion genomic diagnosis offers valuable information to help define the mechanisms of drug resistance and to guide the selection of subsequent treatment.