Disclosed is a composition comprising (a) a plurality of intact, bacterially-derived minicells, wherein each minicell of said plurality encompasses regulatory RNA that is packaged in said minicell, and (b) a pharmaceutically acceptable carrier therefor, wherein there is an absence from said minicells of a construct for in situ expression of said regulatory RNA, wherein said regulatory RNA is selected from the group consisting of siRNA, miRNA and shRNA, and wherein said plurality contains a therapeutically effective amount of said regulatory RNA. Also disclosed is the use of the said composition in the preparation of a medicament for the treatment of cancer.
