Rational Design of Triazole Hydrazide Derivatives With Imidazo[2,1‐ <i>b</i> ]thiazole Scaffolds as Targeted EGFR Inhibitors in NSCLC

ABSTRACT A novel series of triazole hydrazide derivatives 8a‐o was rationally designed, synthesized, and systematically evaluated for their anticancer potential. Cytotoxicity screening against A549 lung adenocarcinoma cells identified compounds 8a‐d as the most potent, exhibiting IC 50 values of 3.15–4.93 µM, which are comparable to doxorubicin (IC 50 = 2.77 µM). Mechanistic studies revealed that lead compound 8a induced apoptosis through upregulation of Bax and caspase‐3 and downregulation of Bcl‐2. Additionally, 8a significantly inhibited A549 cell migration (34.46% wound closure vs. 61.61% in controls) and reduced clonogenic survival (surviving fraction = 0.5725). Importantly, 8a displayed low cytotoxicity toward normal lung fibroblasts (WI‐38, IC 50 = 47.21 µM). Enzyme inhibition assays demonstrated potent EGFR kinase inhibition by 8a and 8 d (IC 50 = 74.85 and 75.87 nM, respectively), comparable to erlotinib (IC 50 = 34.89 nM). Moreover, in silico ADMET profiling predicted favorable drug‐likeness and oral bioavailability, while molecular docking supported the stable binding of 8a within the EGFR active site. These findings identify compound 8a as a promising therapeutic lead for the development of targeted EGFR inhibitors in non‐small cell lung cancer (NSCLC) therapy.