BI-1622 is an orally active, potent and highly selective HER2 ( ERBB2 ) inhibitor, with an IC 50 of 7 nM. BI-1622 shows greater than 25-fold selectivity over EGFR . BI-1622 shows high antitumor efficacy in vivo in xenograft mouse tumor models with engineered H2170 and PC9 cells and had a favorable agent metabolism and pharmacokinetics profile.