Flubendazole delays tumor growth and reduces tumor weight in leukemia and myeloma mouse xenografts. Sublethally irradiated SCID mice were injected subcutaneously with OCI-AML2 cells (n = 20; 10 per group). After implantation, mice were treated with 50 mg/kg flubendazole (A), 20 mg/kg flubendazole (B), or vehicle control by intraperitoneal injection daily. Tumor volume was measured over time. After 16 days (20 mg/kg dose) or 18 days (50 mg/kg dose), mice were killed and tumors were excised, measured, and weighed. (C) Sublethally irradiated SCID mice were injected subcutaneously with OPM2 cells (n = 20; 10 per group). Mice were treated with 50 mg/kg flubendazole or vehicle control by intraperitoneal injection twice daily. Tumor volume and body weight were measured over time. After 17 days, mice were killed and tumors were excised, measured, and weighed. Data are mean ± SEM. Differences in tumor volume and tumor weight were analyzed by an unpaired t test **P < .001, *P < .05.