A small, cyclic pentapeptide vascular-targeting agent with potential antineoplastic and antiangiogenic activities. ADH-1 selectively and competitively binds to and blocks N-cadherin, which may result in disruption of tumor vasculature, inhibition of tumor cell growth, and the induction of tumor cell and endothelial cell apoptosis. N-cadherin, a cell- surface transmembrane glycoprotein of the cadherin superfamily of proteins involved in calcium-mediated cell-cell adhesion and signaling mechanisms; may be upregulated in some aggressive tumors and the endothelial cells and pericytes of some tumor blood vessels.