<n0:ComplexDefinition xmlns:n0="http://ncicb.nci.nih.gov/xml/owl/EVS/ComplexProperties.xsd#"><n0:def-definition>A liposome-encapsulated formulation of lurtotecan with antineoplastic activity. Lurtotecan, a semisynthetic analogue of camptothecin, selectively stabilizes the topoisomerase I-DNA covalent complex and forms an enzyme-drug-DNA ternary complex during S phase of the cell cycle, thereby inhibiting religation of topoisomerase I-mediated single-stranded DNA breaks. This ultimately results in an inhibition of DNA replication, inducing double-stranded DNA breakages, obstruction of RNA and protein synthesis and triggering apoptosis. Furthermore, this agent also stimulates degradation of topoisomerase I, likely mediated through ubiquitin-proteasomal pathway. Liposomal delivery of lurtotecan improves its penetration and delivery into tumors while lowering systemic side effects.</n0:def-definition><n0:def-source>NCI</n0:def-source></n0:ComplexDefinition>