Irinotecan hydrochloride (CPT-11) is a water-soluble semisynthetic derivative of camptothecin. CPT-11 is a prodrug that undergoes deesterification in vivo to produce SN-38, a metabolite that is 1,000-fold more potent than the parent compound in vitro. CPT-11 is a potent topoisomerase I inhibitor with a broad spectrum of experimental antitumor activity. Recent clinical trials also reveal that CPT-11 is very effective in the treatment of cancers including lung cancer, cervix cancer, ovary cancer, etc. Now, comparative trials of combination chemotherapy in responsive tumors are indicated from these excellent clinical results.