First line osimertinib for the treatment of patients with advanced EGFR-mutant NSCLC

Molecular profiling in patients with newly diagnosed advanced non-small cell lung cancer (NSCLC) has become routine in clinical practice, allowing us to provide the most effective treatment to individuals harboring actionable genetic alterations. Activating epidermal growth factor receptor (EGFR) mutations are present in approximately 10–15% of Caucasian patients and 35–40% East Asian patients with NSCLC (1). Together, in frame deletions in exon 19 at the LeuArgGluAla sequence (E746-A750), and the exon 21-point mutation Leu858Arg (L858R), account for nearly 85–90% of all EGFR mutations in NSCLC, and predict exquisite sensitivity to EGFR tyrosine kinase inhibitors (TKIs) (1). On the other hand, 10–18% of all EGFR mutations primarily consist of exon 20 insertions, exon 18 point mutations and complex mutations. Although improved detection techniques have enlarged the spectrum of genetic alteration within the ‘uncommon group’ their predictive role is variable and not yet fully enlighten (2)