Gefitinib is an
anilinoquinazoline with antineoplastic activity. Gefitinib inhibits the catalytic activity of numerous
tyrosine kinases including the epidermal growth factor receptor (EGFR), which may result in inhibition of
tyrosine kinase-dependent tumor growth. Specifically, this agent competes with the binding of
ATP to the
tyrosine kinase domain of EGFR, thereby inhibiting receptor autophosphorylation and resulting in inhibition of signal transduction. Patients with advanced epidermal growth factor receptor (
EGFR) mutated non–small- cell lung cancer (NSCLC)
treated with tyrosine kinase inhibitors (TKIs), such as gefitinib, erlotinib, and afatinib, show improved progression-free survival (PFS) compared with standard chemo-
therapy as first-line
therapy.