THERAPY OF CANCER METASTASIS BY TUMORICIDAL ACTIVATION OF TISSUE MACROPHAGES USING LIPOSOME-ENCAPSULATED IMMUNOMODULATORS

The therapy of cancer requires strategies that can eradicate metastati c disease. Metastases consist of unique subpopulations of tumor cells that are able to colonize distant organs and become autonomous from ho meostatic mechanisms. Conventional therapies generally have been unsuc cessful due to biological heterogeneity in metastatic tumors. It is po ssible to circumvent this heterogeneity by the tumoricidal activation of tissue macrophages. Activation can be achieved by encapsulation of immunomodulators, e.g., muramyl tripeptide analogues, into liposomes, and this form of immunomodulation leads to eradication of established tumor metastases in numerous animal tumor models. Modulation of the tu mor microenvironment by activated macrophages may prove to be an addit ional modality in therapy that combines the use of biological response modifiers with conventional therapies. (C) 1998 Elsevier Science Inc.