A selective ETA receptor antagonist (IC50s = 21 and >10,000 nM for human recombinant ETA and ETB, respectively); inhibits ET-1-induced growth of HEY, OVCA 433, SKOV3, and A2780 cells in vitro; reduces ET-1-induced expression of MMP-2, MMP-9, VEGF, COX-1 and COX-2 in HEY cells; reduces tumor growth in an HEY mouse xenograft model in a dose-dependent manner (10-50 mg/kg per day)