Melflufen (Melphalan flufenamide), a dipeptide proagent of Melphalan, is an alkylating agent. Melflufen exhibits significant antitumor activity against multiple myeloma (MM) cells and has been shown to inhibit angiogenesis. Melflufen induces irreversible DNA damage and cytotoxicity in MM cells, thereby contributing to its antitumor efficacy. At equivalent molar concentrations, both the salt and free forms of Melflufen exhibit comparable biological activity. However, the salt form, Melflufen hydrochloride, typically demonstrates enhanced water solubility and stability, which may contribute to its increased therapeutic potential.