A selective antagonist of the activation of VEGFR-3 by VEGF-C (IC50 = 1 µM); does not inhibit ligand-induced autophosphorylation of VEGFR-2, EGFR, IGF-1R, or PDGFRβ; reduces proliferation and induces apoptosis in a variety of cancer cells in vitro and suppresses tumor growth in vivo.