Phenotypic characteristics of hMPLW515L mice treated with vehicle versus INCB16562 at varying doses over time. (A)Treatment with INCB16562 resulted in significant increase in survival at 60 mg/kg and 120 mg/kg doses compared with vehicle as shown by Kaplan-Meier survival curve (P < .001, log-rank test). (B) Mice treated with INCB16562 regained weight lost after tail vein injections compared with vehicle-treated mice, which continued to lose weight. This difference in weights were statistically significant starting at 17 days of treatment with 120 mg/kg per day (P = .007, Mann-Whitney U test) and after 18 days of treatment with 60 mg/kg per day (P = .004, Mann-Whitney U test). (C) Measurement of hematologic parameters at various time points in INCB16562 treatment reveal significant improvement in WBC and platelet counts with 60 mg/kg and 120 mg/kg of INCB16562 at day 14 after treatment initiation. (D) Treatment with INCB16562 resulted in decreased hepatosplenomegaly as measured in organ weight at 12 days of treatment. *P < .05 compared with vehicle-treated mice. (B-D) Error bars denote SD.