EGFR and non-small cell lung carcinoma: In the light of osimertinib’s impressive activity against the dominant biological (i.e., T790M mutation) and pharmacological (i.e., poor CNS penetration) resistance mechanisms to earlier-generation EGFR TKIs in EGFR mutant advanced NSCLC, there were subsequent studies that evaluated the efficacy of osimertinib as a first-line therapy.