Darbufelone is a dual inhibitor of cellular PGF2R and LTB4 production. Darbufelone is orally active and nonulcerogenic in animal models of inflammation and arthritis. When mice are treated with Darbufelone at dosage of 80 mg/kg/day, the tumor volumes decrease in a time-dependent manner. In contrast, lower dose of Darbufelone (20 or 40 mg/kg/day) dos not show any significant inhibition of tumor weight. At necropsy, the tumor weight in mice treated with Darbufelone (80 mg/kg/day) is reduced by 30.2% in comparison with control group.