MAP855 is a highly potent, selective, ATP-competitive and orally active MEK1/2 kinase inhibitor (MEK1 ERK2 cascade IC 50 =3 nM, pERK EC 50 =5 nM). MAP855 shows equipotent inhibition of wild-type and mutant MEK1/2 In Vitro MAP855 (compound 30) has single-digit nM inhibition of pERK and proliferation in A375 cells (pERK EC 50 =5 nM). MCE has not independently confirmed the accuracy of these methods. They are for reference only. Cell Proliferation Assay Cell Line: A375 cellsConcentration: 0-10 nM Incubation Time: 72 hours Result: Showed single-digit nM inhibition of pERK and proliferation in A375 cells (pERK EC 50 =5 nM). In Vivo MAP855 (3 mg/kg for i.v., 10 mg/kg for p.o.; single) has good oral bioavailability and medium clearance in rodents . MAP855 (30 mg/kg; p.o., b.i.d, 14 days) achieves comparable efficacy to trametinib dosed at the mouse MTD without any body weight loss . Pharmacokinetic Parameters of MAP855 in mouse, rat and dog . mouse rat dog CL [mL/min*kg] 32 35 22 V ss [l/kg] 2.6 2.0 1.8 AUC po d.n. [μM*h] 0.4 0.6 1.4 Oral BAV [% F ] 44 65 100 MCE has not independently confirmed the accuracy of these methods. They are for reference only. Animal Model: Male Wistar Rats Dosage: 3 mg/kg for i.v., 10 mg/kg for p.o. Administration: i.v. and p.o., single Result: Showed good oral bioavailability and medium clearance. Animal Model: A375 Tumor Bearing Mice Dosage: 30 mg/kg Administration: p.o., b.i.d, 14 days Result: Achieved comparable efficacy to trametinib dosed at the mouse MTD without any body weight loss. Form:Solid IC50& Target:ERK 5 nM (EC 50 ) MEK1 3 nM (IC 50 )