The sodium salt form of tasisulam, an acyl-sulfonamide compound with potential antiproliferative activity. Tasisulam activates, through an as of yet not fully elucidated mechanism, the intrinsic mitochondrial-mediated cell death pathway as manifested by decreased adenosine triphosphate (ATP), cytochrome C release, activation of caspases, loss of mitochondrial membrane potential, production of reactive oxygen species (ROS) and eventually apoptosis.