Icotinib Hydrochloride (BPI-2009) is a potent and specific EGFR inhibitor with an IC₅₀ of 5 nM; also inhibits mutant EGFR^L858R, EGFR^L858R/T790M, EGFR^T790M and EGFR^L861Q. IC50 & Target: IC50: 5 nM (EGFR)^[1] In Vitro: Incubation with Iconitib at 0.5 μM results in kinase activity inhibition of 91%, 99%, 96%, 61% and 61%, respectively. Iconitib inhibits the proliferation of A431 and BGC-823 A549, H460 and KB cell lines with IC₅₀s of 1, 4.06, 12.16, 16.08, 40.71 μM. When profiled with 88 kinases, Icotinib only shows meaningful inhibitory activity to EGFR and its mutants. Icotinib blocks EGFR-mediated intracellular tyrosine phosphorylation (IC₅₀=45 nM) in the human epidermoid carcinoma A431 cell line and inhibits tumor cell proliferation^[1]. In Vivo: Icotinib exhibits potent dose-dependent antitumor effects in nude mice carrying a variety of human tumor-derived xenografts. The drug is well tolerated at doses up to 120 mg/kg/day in mice without mortality or significant body weight loss during the treatment. Icotinib inhibits tumor growth at a rate of 25.2%, 45.6% and 51.5% in the A431 cell line groups; 3.4%, 25.9% and 31.0% in the A549 cell line groups; 49.4%, 52.6% and 67.4% in the H460 cell line groups, and 30.3%, 36.4% and 46.5% in the HCT8 cell line groups, at 30, 60 and 120 mg/kg/dose, respectively^[1].