The use of a vitamin A analog called 4-HPR, or fenretinide, in combination with certain other drugs, or ‘partnering agents’, is reportedly showing promise for selectively killing certain types of cancer cells. Fenretinide works by stimulating overproduction of normal cellular waxes in cancer cells, that when produced in excess are lethal to cancer cells.
Fenretinide, either as a single agent or in combination with a partnering drug that slows degradation of the lethal waxes, appears to be therapeutic, especially in the case of recurring or relapsed malignant disease. The application would be for both adults and children, according to the John Wayne Cancer Institute.
Intravenous fenretinide emulsion is in Phase I trials for pediatric neuroblastomas and leukemia, and in adult solid tumor and blood cancers. In a Phase II study of recurrent ovarian cancer, high plasma levels of fenretinide were associated with improved outcome.