Figure 7. Belinostat potentiates volasertib activity against systemic OCI-Ly18 in a murine xenograft model and prolongs animal survival.

OCI-Ly18/Luciferase cells were injected into NOD/SCID-gamma mice via tail vein (7.5 × 10⁶ cells). The mice were then injected with firefly luciferin and imaged by IVIS twice weekly. Treatment was initiated after tumors (OCI-Ly18/Luc) were visualized and randomly grouped. Studies involved 5 mice per group. Belinostat was administrated at a dose of 80 mg/kg by intraperitoneal injection (i.p.) 5 days a week. Volasertib was administered at a dose of 12 mg/kg via i.p. injection once a week. Control animals were administered equal volumes of vehicle. Treatment was discontinued after day 21. A. Tumor growth was monitored twice weekly by injection luciferin followed by imaging by the IVIS 200 imaging system. d=day, empty boxes represent deceased mice. B. Survival of mice treated as above was evaluated from the first day of treatment until death using Kaplan–Meier curves. The survival of mice treated with the combination was significantly prolonged compared to mice treated with single agents, p< 0.001. C. Cells from bone marrow obtained from one mouse in each group after 2 weeks of treatment were stained with fluorescently-labeled CD45 antibodies, after which they were analyzed by flow cytometry.