PYZD-4409 delays tumor growth in mouse model of leukemia. (A) MDAY-D2 murine leukemia cells (1 × 105) were injected subcutaneously into male SCID mice (n = 20). Starting the next day, animals were treated with PYZD-4409 (10 mg/kg; n = 10) in saline by intraperitoneal injection or vehicle alone (n = 10) once every other day over 8 days. Tumor growth was monitored at least every other day by external calipers. (B) At 16 days after tumor injection, mice were killed, and tumors were excised and weighed. Data represent the mean tumor weight ± SD. A representative experiment is shown.