Liposome Encapsulated SN38 (LE-SN38) is an oncology drug product consisting of the active metabolite of irinotecan (CPT-11), a known anticancer drug, encapsulated in a liposome. Formulation of a relatively insoluble compound (SN38) and improvement in drug delivery (pharmacodynamic profile) may be obtained with liposomal formulations. An improved safety and efficacy profile, compared with the pro-drug CPT-11, may be possible. This rationale is supported by the results from animal toxicity studies in both the mouse and dog.