A form of the anticancer drug irinotecan that is contained in very tiny, fat-like particles. It may have fewer side effects and work better than irinotecan alone. Liposomal SN-38 is being studied in the treatment of advanced colorectal cancer and other types of cancer. Liposomal SN-38 blocks the ability of cells to divide and grow. It may stop the growth of tumor cells. It is a type of topoisomerase inhibitor and a type of irinotecan (CPT-11) derivative. Also called SN-38 liposome.