Preclinical studies for a cationic liposome formulation containing Il-2 Intended for the treatment of Human Tumors

Abstract

Human cervical cancer tumours expressing the IL-2 receptor (IL-2R) were induced in the peritoneal cavity of nude mice. The tumours were signifi cantly reduced by the i.p. administration of either free IL-2 or liposomes containing this growth factor. No toxicity was observed in the mice even at the highest doses of IL-2 in liposomes. We did not detect any IL-2 in the blood plasma pointing to a strong retention of the liposomes on the cavity. We concluded that this preclinical study for the treatment of tumours expressing IL-2R in the peritoneal cavity is effective and safe. The liposomes were stable and their IL-2 active for up to one year when kept at-14 o C in a cryopreservation media approved by the FDA for human use.