Selective focal adhesion kinase (FAK) inhibitor that displays no significant activity at a range of other kinases including EGFR, PDGFR and IGF-RI. Prevents FAK autophosphorylation at Y397 (IC50 = 1 μM), promotes cell detachment and inhibits cell adhesion in vitro. Exhibits antiproliferative activity in a variety of human tumor cell lines in vitro and in breast cancer cells in vivo.