Melphalan flufenamide, sold under the brand name Pepaxto, is an anticancer medication used to treat multiple myeloma. The most common adverse reactions include fatigue, nausea, diarrhea, pyrexia and respiratory tract infection. Melphalan flufenamide is a peptidase enhanced cytotoxic (PEnC) that exerts a targeted delivery of melphalan in cells with high expression of aminopeptidases, such as aminopeptidase N, which has been described as over-expressed in human malignancies. Aminopeptidase N plays a functional role in malignant angiogenesis.