A potent and selective inhibitor of insulin-like growth factor 1 receptor (IGF1R) which is non-competitive with ATP. Displays no activity at IR, EGFR, FGFR or PDGFR. Inhibits IGF1R autophosphorylation IC₅₀ ~ 1 nM. Displays antiproliferative activity in numerous tumor cell lines, IC₅₀ = 0.05 - 15 mM. Exhibits antiangiogenic activitiy.