ZIO-101 is an organic arsenic derivative. In vitro testing in both the National Cancer Institute (NCI) cancer cell panel and in vivo testing in a leukemia animal model demonstrated substantial activity of SGLU against hematologic cancers. In vitro testing of SGLU using the NCI human cancer cell panel also detected activity against lung, colon and brain cancers, melanoma, and ovary and kidney cancers. Moderate activity was seen against breast and prostate cancers cells. Data suggest that organic arsenic generates reactive oxygen species in the cells to induce apoptosis and cell cycle arrest.