Five compounds which were identified as potential new anticancer drugs in in vitro screening with the human tumor colony forming assay were selected for further evaluation using in vitro and in vivo models of human ovarian cancer. Three of five compounds were found to inhibit in vitro colony formation of ovarian cancer cell lines derived from both untreated and combination chemotherapy refractory patients. One compound was also found to prolong survival in a human ovarian carcinoma xenograft model system. This compound, chloroquinoxaline sulfonamide, was selected for development and has shown preliminary indication of activity in phase I clinical testing.