Effects of dosing and schedule of sorafenib on tumor growth. Treatment was initiated when tumors reached 12 mm in long axis (volume ~500 mm3) with the administration of vehicle or different doses and schedule of sorafenib orally as indicated. All animals were sacrificed and tumors were dissected ~36 days post treatment with the exception of vehicle treated mice which were sacrificed when tumors reached the mandated 20 mm sacrifice size (~22 days post treatment, volume ~2500 mm3). Figure 1A shows that treatment with high dose intermittent therapy inhibited tumor growth to a greater extent than conventional dose continuous and intermittent therapy. Data are presented as mean tumor volume with SEM. Figure 1B presents the tumor volume on the average day when vehicle treated tumors reached 20 mm in long axis (~22 days post treatment). The tumor volume of mice with high dose intermittent therapy is significantly smaller than that of conventional dose continuous therapy (P < 0.05) while the volume did not differ in the high dose intermittent vs high dose continuous or conventional dose intermittent vs conventional dose continuous arms (P > 0.05).