CEP-32496 is a selective inhibitor of BRAFV600E with IC50 value of 669 nM .
BRAF is a member of Raf kinase family and plays an important role in sending signals (directing cell growth) inside cells. BRAF involves in regulating MAP kinase/ERKs signaling pathway and mutant BRAFV600E activates MAPK pathway, it has been shown that BRAF mutant BRAFV600E is correlated with several human cancers .
CEP-32496 is a potent BRAFV600E inhibitor and has a different selectivity with the reported BRAFV600E inhibitor RG7204. Using Ambit Kinomescan Assay, it was shown that CEP-32496 potently binding to RAF family with Kd value ranged from 14 to 39 nmol/L. When tested with a panel of BRAF mutant (A375, SK-MEL-28, Colo-679, HT-144, and Colon-205) cell lines, CEP-32496 showed a selective cytotoxicity profile against tumor cell lines with V600E mutant while had no effect on wild type cell lines (HCT116, Hs578T, LNCaP, DU145, PC-3) . CEP-32496 treatment exhibited high cytotoxicity against human tumor cell lines with expression of BRAFV600E while had little effect on wild type BRAF expressed cell lines .
In nude mice model with Colo-205 tumor cells subcutaneous xenograft, oral administration of CEP-32496 significantly inhibited pMEK normalization, induced tumor stasis (40%) while control group did not have this phenomenon in a dose of 30 mg/kg .
CEP-32496 also inhibits MEK phosphorylation with IC 50 value of 60 nM .
.James, J., et al., CEP-32496: a novel orally active BRAF(V600E) inhibitor with selective cellular and in vivo antitumor activity. Mol Cancer Ther, 2012. 11(4): p. 930-41.
.Rowbottom, M.W., et al., Identification of 1-(3-(6,7-dimethoxyquinazolin-4-yloxy)phenyl)-3-(5-(1,1,1-trifluoro-2-methylpropa n-2-yl)isoxazol-3-yl)urea hydrochloride (CEP-32496), a highly potent and orally efficacious inhibitor of V-RAF murine sarcoma viral oncogene homologue B1 (BRAF) V600E. J Med Chem, 2012. 55(3): p. 1082-105.