Sobuzoxane, a novel bis(2,6-dioxopiperazine) derivative, was introduced in
Japan for the treatment of malignant lymphoma and adult T-cell IeukemiaQmphoma
(ATLL), which is resistant to chemotherapy and has a poor prognosis. Sobuzoxane
exhibits 8 broad spectrum of antitumor activity. It is a noncleavable complexstabilizing
topoisomerase II inhibitor and exerts its function via interfering with the
catalytic activity of the enzyme to result in an irreversible inhibition of cell division by
blockade of chromosome condensation and segregation. Due to Its unique mode of
cytocidai activity, it has no cross resistance with many currently available
anticancer agents. Sobuzoxane is reported to significantly inhibit growth of human
colon, lung, gastric, and breast cancers and is in clinical trials for these indications.
