WZ4002

WZ4002 is a novel mutant-selective epidermal growth factor receptor (EGFR) kinase inhibitor that potently and irreversibly suppresses the ATP-dependent auto-phosphorylation of both wild-type EGFR and EGFR mutants, including EGFR delE746_A750/T790M, EGFR L858R/T790M, EGFR T790M, EGFR delE746_A750 and EGFR L858R, with inhibition constant Ki of 13.6 nM, 1.8 nM, 4 nM, 5 nM, 3.9 nM and 8.5 nM respectively. Although WZ4002 is actively against EGFR mutants rather than wild-type EGFR at lower concentrations resulting in less toxicity in normal tissues, wild-type EGFR is susceptible to higher concentrations of WZ4002 as well as prolonged administration of WZ4002, especially in tissues where it accumulates.

References:
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WZ4002, a third-generation EGFR inhibitor, can overcome anoikis resistance in EGFR-mutant lung adenocarcinomas more efficiently than Src inhibitors.[Pubmed:22157722]

Lab Invest. 2012 Mar;92(3):371-83.

Src has a role in the anoikis resistance in lung adenocarcinomas. We focused on two epidermal growth factor receptor (EGFR)-mutant lung adenocarcinoma cell lines, HCC827 (E746-A750 deletion) and H1975 (L858R+T790M), in suspension to elucidate whether suspended lung adenocarcinoma cells are eradicated by long-term treatment with Src tyrosine kinase inhibitors (TKIs). We also examined metastasis-positive lymph nodes from 16 EGFR-mutant lung adenocarcinoma patients for immunohistochemical expression of mutant-specific EGFR. Almost all suspended HCC827 cells underwent apoptosis after 144 h of combination treatment with AZD0530, trichostatin A (TSA), and ABT-263, whereas many suspended H1975 cells survived the treatment. AZD0530 is a Src TKI, TSA is a histone deacetylase inhibitor, and ABT-263 is a Bcl-2 inhibitor. During the therapy, the phosphorylation of EGFR decreased in HCC827 cells and remained stable in H1975 cells. The phosphorylated EGFR of Src TKI-resistant H1975 cells, as well as HCC827 cells, was completely suppressed by the third generation EGFR TKI, WZ4002. Consequently, both the suspended cell lines were almost completely eradicated within 144 h, with the combined therapy of WZ4002, ABT-263, and TSA. Interestingly, treated suspended cells underwent apoptosis to a greater extent than did adherent cells. Intrasinus floating lung adenocarcinoma cells in the lymph nodes expressed a mutant-specific EGFR. These findings suggest that suspended EGFR-mutant lung adenocarcinoma cells depend significantly more on EGFR activation for survival than attached cells do. The tumor cells circulating in vessels, which express mutant-specific EGFR, would be highly susceptible to the combination therapy of WZ4002, ABT-263, and TSA.