MEK heterocyclic inhibitors and methods of use thereof

Compound having formula IV: ** Formula ** or a pharmaceutically acceptable salt thereof, wherein: R1 is Cl or F; R3 is H, Me, Et, OH, MeO-, EtO-, HOCH2CH2O-, HOCH2C (Me) 2O-, (S) -MeCH (OH) CH2O-, (R) - HOCH2CH (OH) CH2O-, cyclopropyl- CH2O-, HOCH2CH2-, R7 is methyl or ethyl, wherein said methyl and ethyl are optionally substituted with one or more F; R8 is Br, I or SMe; and R9 is H, C1-C4 alkyl, Cl or CN, wherein said alkyl is optionally substituted with one or more groups independently selected from F or CN, provided that when a) R1 is F, R8 is Br, R9 is H and R7 is either Me or Et, so R3 cannot be HOCH2CH2O; b) R1 is F, R8 is I, R9 is H and R3 is MeO, so R7 cannot be Me; c) R1 is F, R8 is Me, R9 is H and R3 is HOCH2CH2O, so R7 cannot be Me; and d) R1 is F, R8 is Br, R9 is H and R3 is cyclopropyl-CH2O, so R7 cannot be Me.