4-Desethyl-4-deshydroxy-4-oxo-topotecan-d6 is a labelled version of 4-Desethyl-4-deshydroxy-4-oxo-topotecan (D291308) which can be obtained from Topotecan Hydrochloride (T542500) which is a DNA topoisomerase I inhibitor; semisynthetic analog of Camptothecin. Antineoplastic. Topotecan hydrochloride is a chemotherapy agent that is a topoisomerase 1 inhibitor.