Treatment of BT549, SK-Br-3 and SK-Ov-3 cells with 250 μg/ml of BP1003 resulted in a 30%-50% decrease in STAT3 expression. Cell viability decreased by 20-35% with 200 μg/ml of BP1003 and by 45-60% in combination with taxol or 5-FU. BP1003 in combination with taxol also decreased the colony formation potential of BT549 cells by 20%. Migration of BT549 cells was reduced by 30% with 200 μg/ml BP1003 alone and by 50% in combination with taxol.BP1003 efficiently reduces STAT3 expression and enhances the sensitivity of breast and ovarian cancer cells to taxol and 5-FU.