N-sulfonylurea apoptosis promoters

A compound of formula (I)

• or a therapeutically acceptable salt thereof, wherein
• A is piperazine;
• R1 is nitro;
• R2 is —NR5R6;
• R3 is hydrogen;
• R4 is selected from the group consisting of aryl and cycloalkyl wherein the aryl group may be optionally substituted with up to 5 substituents selected from the group consisting of alkyl, nitro, halo, phenylalkoxy, morpholinocarbonylalkyl and morpholinoalkyl and the cycloalkyl group may be optionally substituted with up to 5 substituents selected from the group consisting of alkyl, alkoxy and phenylalkyl;
• R5 is hydrogen and R6 is selected from the group consisting of, arylsulfanylalkyl, arylsulfinylalkyl and arylsulfonylalkyl, the alkyl part of each of which is substituted with —NR9R10, wherein R9 and R10 are alkyl;
• and
• R15 is selected from the group consisting of hydrogen, alkoxy, alkyl, and halo.