592801 Disclosed are compounds of formula (I) which inhibit the activity of anti-apoptotic BCL-2 or BCL-XL proteins, compositions containing the compounds and methods of treating diseases during which are expressed anti-apoptotic BCL-2 protein. Examples of compounds of formula (I) include: 4-(4-((4-chloro-1,1-biphenyl-2-yl)methyl)piperazin-1-yl)-N-((3-nitro-4-((tetrahydro-2Hpyran-4-ylmethyl)amino)phenyl)sulfonyl)-2-phenoxybenzamide 4-(4-((4-chloro-1,1-biphenyl-2-yl)methyl)piperazin-1-yl)-2-phenoxy-N-((4-((tetrahydro-2H-pyran-4-ylmethyl)amino)phenyl)sulfonyl)benzamide 4-(4-((4-chloro-1,1-biphenyl-2-yl)methyl)piperazin-1-yl)-N-((3-nitro-4-((tetrahydro-2H-pyran-4-ylmethyl)amino)phenyl)sulfonyl)-2-(phenylthio)benzamide 4-(4-((4-chloro-1,1-biphenyl-2-yl)methyl)piperazin-1-yl)-2-(phenylthio)-N-((4-((tetrahydro-2H-pyran-4-ylmethyl)amino)phenyl)sulfonyl)benzamide.