CRM1 inhibitor increases survival in a human leukemia xenograft model. (A) Survival of MV4-11 xenograft mice after treatment with KPT-276 150 mg/kg (n = 12) or vehicle control (n = 11). Survival comparison was made with log-rank test. (B) White blood cell count (in thousands) in KPT-treated mice versus vehicle control (n = 8) at 21 days. P values obtained using t test. (C) Spleen weights (mg) in KPT-treated mice versus vehicle control (n = 7). P values obtained using t test. (D) Spleen photographs of 3 representative cases (KPT-276 n = 3; vehicle n = 3) at 21 days. (E) FLT3 protein expression in mouse spleen cells as measured by Western blotting after KPT-276 treatment or vehicle control at 21 days.