CP-724714 is obvious selectively against EGFR (IC50: 6.4 μM). CP-724714 is >1,000-fold less potent for IGF-1R, IR, VGFR2, PDGFRβ, Src, ZAP-70, JNK-2/3, and CDK-2/5. CP-724714 markedly reduces the EGF-induced autophosphorylation of the chimera containing the erbB2 kinase domain (IC50: 32 nM). CP-724714 inhibits the proliferation of erbB2-amplified cells including BT-474 (IC50: 0.25 μM) and SKBR3 (IC50: 0.95 μM). CP-724714 (1 μM) induces the accumulation of cells in G1 phase and a marked reduction in S-phase in BT-474 cells. CP-724714 inhibits TC transport in membrane vesicles expressing human bile salt export pump (IC50: 16 μM) and inhibits the major efflux transporter in bile canaliculi, MDR1 (IC50: 28 μM).

CP-724714 (25 mg/kg) is rapidly absorbed after p.o. administration and causes reduction of tumor erbB2 receptor phosphorylation after dosing in FRE-erbB2 or BT-474 xenografts. CP-724,714 induces apoptosis in FRE-erbB2 xenograft-bearing (s.c.) mice and shows 50% tumor growth inhibition at 50 mg/kg, without mortality or weight loss. In MDA-MB-453, MDA-MB-231, LoVo (colon), and Colo-205 (colon) xenografts, CP-724714 also has great antitumor activity. In BT-474 xenografts, CP-724714 (30/100 mg/kg) reduces the extracellular signal-regulated kinase and Akt phosphorylation.