CEP-32496 (free base)

B-Raf is a MAP kinase kinase kinase, which functions downstream of Ras family GTPases to activate MEK1/2 and ERK1/2 signaling. Mutations of B-Raf, particularly at Val⁶⁰⁰, are common in melanomas and melanocytic nevi. CEP-32496 is a potent inhibitor of B-Raf^V600E (K_d = 14 nM in an in vitro binding assay). It blocks B-Raf^V600E-dependent phosphorylation of MEK in human melanoma A375 and colorectal cancer COLO 205 cells (IC₅₀s = 78 and 60 nM, respectively). CEP-32496 binds kinases other than B-Raf but displays selective cytotoxicity for cells expressing B-Raf^V600E. It displays good oral bioavailability in rats, dogs, and monkeys and has single oral dose pharmacodynamics inhibition of both pMEK and pERK in B-Raf^V600E colon carcinoma xenografts in nude mice.

CEP 32496 is an orally active BRAFV600E inhibitor with selective cellular and in vivo antitumor activity.

[1] rowbottom mw1, faraoni r, chao q, campbell bt, lai ag, setti e, ezawa m, sprankle kg, abraham s, tran l, struss b, gibney m, armstrong rc,gunawardane rn, nepomuceno rr, valenta i, hua h, gardner mf, cramer md, gitnick d, insko de, apuy jl, jones-bolin s, ghose ak, herbertz t, ator ma,dorsey bd, ruggeri b, williams m, bhagwat s, james j, holladay mw. identification of 1-(3-(6,7-dimethoxyquinazolin-4-yloxy)phenyl)-3-(5-(1,1,1-trifluoro-2 -methylpropan- 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 feb 9;55(3):1082-105. doi: 10.1021/jm2009925. epub 2012 jan 23.