EGFR-IN-1 hydrochloride is an orally active and irreversible L858R/T790M mutant selective EGFR inhibitor. EGFR-IN-1 hydrochloride potently inhibits Gefitinib-resistant EGFR L858R, T790M with 100-fold selectivity over wild-type EGFR. EGFR-IN-1 hydrochloride displays strong antiproliferative activity against the H1975 cells and the first line mutant HCC827 cells. Antitumor activity.