<unk>  is an alkylating agent that is FDA approved for the treatment of multiple myeloma and for the palliation of non-resectable epithelial carcinoma of the ovary. There is a Black Box Warning for this drug as shown here.  Common adverse reactions include stomatitis.
Melphalan
Ifosfamide
Mafosfamide
Busulfan 
Carmustine 
Lomustine
Fotemustine
Semustine