EGFR and non-small cell lung carcinoma: Osimertinib is a 3rd-generation EGFR-TKI approved for the treatment of EGFR-mutated NSCLC and is also effective against T790M mutation-positive cases, frequently observed after treatment with 1st- or 2nd-generation EGFR inhibitors, such as gefitinib, erlotinib, or afatinib.