A synthetic analogue of the nitrogen mustard cyclophosphamide with antineoplastic activity. Ifosfamide alkylates and forms DNA crosslinks, thereby preventing DNA strand separation and DNA replication. This agent is a prodrug that must be activated through hydroxylation by hepatic microsomal enzymes. or A drug that is used with other drugs to treat germ cell testicular cancer that did not respond to previous treatment with other drugs. It is also being studied in the treatment of other types of cancer. Ifosfamide attaches to DNA in cells and may kill cancer cells. It is a type of alkylating agent and a type of antimetabolite. Also called Ifex.