Irinotecan HCl

Irinotecan is a semi-synthetic derivative of camptothecin that is an FDA approved anticancer drug. It is a prodrug that is converted by tissue esterases to 7-ethyl-10-hydroxycamptothecin (SN-38), a potent inhibitor of DNA topoisomerase I.1,2 Although irinotecan is also a topoisomerase inhibitor, SN-38 is approximately 1000 times as potent in purified enzyme studies. In vitro cytotoxicity assays show much greater variability in potency between the two (2-2000 fold) .3