Cilengitide hydrochloride sis the salt form of Cilengitide, a cyclic Arg-Gly-Asp peptide with potential antineoplastic activity. Cilengitide binds to and inhibits the activities of the alpha(v)beta(3) and alpha(v)beta(5) integrins, thereby inhibiting endothelial cell-cell interactions, endothelial cell-matrix interactions, and angiogenesis.