The liposomal formulation of SN-38 (7-ethyl-10-hydroxy-camptothecin), a biologically active metabolite of the prodrug irinotecan, with potential antineoplastic activity. SN-38 binds to and inhibits topoisomerase I by stabilizing the cleavable complex between topoisomerase I and DNA, resulting in DNA breaks, inhibition of DNA replication, and apoptosis. SN-38 has been reported to exhibit up to 1,000-fold more cytotoxic activity against various cancer cells in vitro than irinotecan. The liposomal formulation of SN-38 increases the solubility of SN-38, which is a relatively insoluble compound, and improves the pharmacodynamic profile as compared to SN-38 alone. or 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.