Tarloxotinib bromide (TH-4000) is an irreversible EGFR/HER2 inhibitor. In Vitro To confirm the mechanism of action, Tarloxotinib bromide is shown to be metabolized efficiently under hypoxia using a panel of human NSCLC cell lines (rate of TKI release 0.4-2.1 nM/hr/10 6 cells), a process that is inhibited by oxygen (TKI release 80% (538 vs 99 nM/kg; p In Vivo A prototypic WT EGFR driven xenograft model (A431) is used to benchmark Tarloxotinib bromide activity against each EGFR-TKI by “retrotranslation” of reported plasma exposure for each agent in human subjects back to the xenograft model. Only treatment with clinically relevant doses and schedules of Tarloxotinib bromide is associated with tumor regression and durable inhibition of WT EGFR tumor phosphorylation. Consistent with these findings, Tarloxotinib bromide treatment can also regress the WT EGFR NSCLC tumor models H125 and H1648, demonstrating Tarloxotinib bromide provides the necessary therapeutic index to inhibit WT EGFR in vivo . MCE has not independently confirmed the accuracy of these methods. They are for reference only. Form:Solid IC50& Target:EGFR/HER2