In vitro activity: WZ8040 is 30- to 100-fold more potent against EGFR T790M, and up to 100-fold less potent against wild-type EGFR, than quinazoline-based EGFR inhibitors such as CL-387785 and HKI-272. WZ8040 treatment potently inhibits the growth of HCC827 (EGFR Del E746_A750), PC9 (EGFR Del E746_A750), H3255 (EGFR L858R), H1975 (EGFR L858R/T790M), and PC9 GR (EGFR Del E746_A750/T790M) with IC50 of 1 nM, 6 nM, 66 nM, 9 nM, and 8 nM, respectively. WZ8040 weakly inhibits the growth of HCC827 GR (EGFR E746_A750/MET amp), H1819 (ERBB2 amp), Calu-3 (ERBB2 amp), H1781 (ERBB2 Ins G776V, C), and HN11 (EGFR & ERBB2 WT) with IC50 of>3.3 μM, 738 nM, 915 nM, 744 nM, and 1.82 μM, respectively. WZ8040 is not toxic up to 10 μM against A549 (KRAS mutant) or H3122 (EML4-ALK) cells.

Cell Assay: Cells (HCC827, H3255, HCC827 GR, H1975, PC9, PC9 GR, Calu-3, H1819, and Ba/F3) are exposed to increasing concentrations of WZ8040 for 72 hours. Growth is assessed using the MTS survival assay.