An integrin αVβ3 receptor antagonist; inhibits adhesion and induces apoptosis of U87MG and U373MG, but not U251MG cells that lack the integrin αVβ3 receptor, in vitro at a concentration of 20 μg/ml; delays tumor implantation time, reduces tumor growth, and prolongs survival in a U87MG mouse model of glioblastoma when administered at a dose of 200 μg/animal per day