Thiotepa

Thiotepa is an anti-cancer medication sold under the brand name Tepadina, an organophosphorus compound with the formula tris(aziridin-1-yl)phosphine sulfide. It acts as an alkylating agent: its aziridine rings open to form reactive aziridinium ions that attack guanine bases in DNA, both alkylating single sites and crosslinking the two DNA strands, which blocks replication and stops cells from dividing. It is used as conditioning therapy before stem cell transplantation for blood cancers such as Hodgkin lymphoma and leukemia, for solid tumors in adults and children, for palliative treatment of breast, ovarian, thyroid and bladder cancers, and, particularly in Japan, for high risk neuroblastoma. American Cyanamid patented the compound in 1952 and it entered human trials the following year.