The present invention relates to methods of treating cancer using a combination of a compound which is an antineoplastic agent and a compound which is a inhibitor of prenyl-protein transferase, which methods comprise administering to said mammal, either sequentially in any order or simultaneously, amounts of at least two therapeutic agents selected from a group consisting of a compound which is an antineoplastic agent and a compound which is a inhibitor of prenyl-protein transferase. The invention also relates to methods of preparing such compositions.