Pelitinib (EKB-569; WAY-EKB 569) is a potent irreversible EGFR inhibitor with IC50 of 38.5 nM.
IC50 value: 38.5 nM [1]
Target: EGFR
in vitro: Pelitinib displays much higher inhibitory activity against EGFR, compared with the closely related c-erbB-2, as well as other kinases such as Src, Cdk4, c-Met, Raf, and MEK/ERK, with IC50 ranging from 282 nM for Src to >20 μM for Cdk4. Consistently, Pelitinib treatment significantly inhibits the autophosphorylation of EGFR but not c-Met in A431 cells [1]. Pelitinib potently inhibits the proliferation of normal human keratinocytes (NHEK), as well as A431 and MDA-468 tumor cells with IC50 of 61 nM, 125 nM, and 260 nM, respectively, while displaying little activity against MCF-7 cells with IC50 of 3.6 μM. Pelitinib inhibits EGF-induced phosphorylation of EGFR in A431 and NHEK cells with IC50 of 20-80 nM, as well as the phosphorylation of STAT3 with IC50 of 30-70 nM. Pelitinib at 75-500 nM also specifically inhibits the activation of AKT and ERK1/2, without affecting NF-κB pathway. In NHEK cells, Pelitinib also potently inhibits TGF-α mediated EGFR activation with IC50 of 56 nM, as well as activation of STAT3 and ERK1/2 with IC50 of 60 nM and 62 nM, respectively [2].
in vivo: A single oral dose of 10 mg/kg Pelitinib potently inhibits the EGFR phosphorylation in A431 xenografts with over-expressed EGFR, by 90% within 1 hour, and by >50% after 24 hours. Administration of Pelitinib at 20 mg/kg/day inhibits tumorigenesis in APCMin/+ mice by 87%, equivalent to the effect of used with 2 times doses of EKI-785 (40 mg/kg/day), consistent with greater in vivo potency [1]. Pelitinib selectively inhibits EGFR signaling in airway epithelial cells in vivo. In the mouse model of airway epithelial remodeling that is inducible by viral infection and features a delayed but permanent switch to goblet cell metaplasia, Pelitinib treatment at 20 mg/kg/day corrects all 3 aspects of epithelial remodeling, by completely blocking the increase of ciliated cells and decrease of Clara cells, and significantly inhibiting the metaplasia of goblet cells [3]. |
