Dimeric IAP inhibitors

A compound of formula (II):

• or a pharmaceutically acceptable salt thereof,
• wherein R1 and R2 are independently H, tert-butoxycarbonyl, benzyloxycarbonyl, acetyl, trifluoroacetyl, alkyl, optionally-substituted alkyl, or
• where R5a and R5b are independently H, alkyl, cycloalkyl, cycloalkylalkyl, aryl, or arylalkyl;
• or each optionally-substituted with hydroxyl, mercapto, halogen, amino, carboxyl, alkyl, haloalkyl, alkoxy, or alkylthio;
• R6a and R6b are independently H, tert-butoxycarbonyl, benzyloxycarbonyl, acetyl, trifluoroacetyl, alkyl, lower alkyl, or optionally-substituted alkyl, or
• where R7a and R7b are independently H, alkyl, cycloalkyl, or haloalkyl;
• R8a and R8b are independently H, hydroxyl, alkyl, aryl, arylalkyl, cycloalkyl, or cycloalkylalkyl, wherein each alkyl, aryl, arylalkyl, cycloalkyl, or cycloalkylalkyl is optionally-substituted with halogen, hydroxyl, mercapto, carboxyl, alkyl, alkoxy, amino, or nitro;
• R3a and R3b are independently H, halogen, alkyl, aryl, arylalkyl, amino, arylamino, arylalkylamino, hydroxy, alkyloxy, aryloxy, arylalkylhydroxy, dialkylamino, amido, sulfonamido, or amidino;
• m and n are 1;
• X and Y are independently N, or C═C;
• R9a and R10a are linked by 4 to 8 optionally-substituted atoms such as C, N, O, or S, to form an aromatic ring;
• R9b and R10b are linked by 4 to 8 optionally-substituted atoms such as C, N, O, or S, to form an aromatic ring;
• Wa and Wb are a bond, alkylene, alkenylene, alkynylene, aryl, arylalkylene, arylalkylalkylene, or an optionally-substituted alkylene, alkenylene, alkynylene chain of 2 to 12 carbon atoms;
• and
• R11a and R11b are independently H, alkyl, optionally-substituted alkyl, hydroxyalkyl, or alkoxyalkyl.