In vivo anti-MM activity of plinabulin. (A) MM.1S cells (5 × 106 in 100 μL of serum-free RPMI-1640 medium) were implanted subcutaneously in mice (7 mice/group); average and standard deviation of tumor volume (mm3) were monitored every third day. Mice were treated intraperitoneally with plinabulin (7.5 mg/kg) or vehicle alone twice weekly for 3 weeks. Bars indicate mean ± SD (P = .05). (B) Body weight of plinabulin-treated versus control mice was monitored once a week. Data show ± SD of 6 different mice/group. (C) Kaplan-Meier plot showing survival of mice treated with plinabulin compared with vehicle-treated controls. (D) Tumors from control and plinabulin-treated mice were subjected to immunostaining with antibodies against cleaved caspase-3 and factor VIII. Photographs are representative of similar observations in 2 different mice receiving the same treatment.
