A synthetic oxazaphosphorine derivative with antineoplastic properties. Mafosfamide alkylates DNA, forming DNA cross-links and inhibiting DNA synthesis. Although closely related to cyclophosphamide, mafosfamide, unlike cyclophosphamide, does not require hepatic activation to generate its active metabolite 4-hydroxy-cyclophosphamide; accordingly, mafosfamide is potentially useful in the intrathecal treatment of neoplastic meningitis. A form of cyclophosphamide that can be administered as an intrathecal infusion. Mafosfamide is being studied as an anticancer drug. It belongs to the family of drugs called alkylating agents.