CP-724714

CP-724714 is a potent, selective and orally active ErbB2 (HER2) tyrosine kinase inhibitor, with an IC₅₀ of 10 nM. CP-724714 displays a marked selectivity against EGFR kinase (IC₅₀=6400 nM). CP-724714 potently inhibits ErbB2 receptor autophosphorylation in intact cells. Antitumor activities^[1][2]. In Vitro: CP-724714 is >1,000-fold less potent for insulin receptor, insulin-like growth factor-I receptor, platelet-derived growth factor β, vascular endothelial growth factor 2, Abl, Src, c-Met, JNK-2, JNK-3, ZAP-70, Cdk-2, and Cdk-5^[1].
CP-724714 potently reduces the EGF-induced autophosphorylation of the chimera containing the erbB2 kinase domain at a concentration as low as 50 nmol/L (IC₅₀=32 nM) but is markedly less potent against EGFR^[1].
CP-724714 (1 μM; 24 hours) induces G1 cell cycle block in vitro in erbB2-overexpressing BT-474 human breast carcinoma cells^[1]. In Vivo: CP-724714 (3.25-100 mg/kg; p.o.; 0.5-8 hours) results in a concentration-dependent reduction of ErbB2 receptor phosphorylation^[1].
CP-724714 (6.25-100 mg/kg; p.o.; q.d; for 8 to 40 day) inhibits FRE-erbB2 xenograft growth^[1].
CP-724714 (Athymic, female FRE-erbB2 xenograft-bearing mice; 30 or 100 mg/kg; p.o.) treatments results in a time- and dose- dependent induction of apoptosis, which was evident as early as 4 to 8 h after dosing. Approximately 75% more tumor cells exhibited apoptotic changes in the 100 mg/kg treatment group compared with vehicle control group at 8 h after dosing. CP-724714 induces regression of BT-474 tumors and significant inhibition in a number of other human tumor xenografts. Additionally, CP-724714 showed a favorable nonclinical toxicity profile with no apparent effects on cardiac tissue^[1].