Differential Toxicities of Kinase Inhibitors (KI) on Bone Marrow Progenitors from Different Species

Myelotoxicity is often a side effect of kinase inhibitors.  We reported a correlation (R2 = 0.81) between in vitro human CFU-GM IC50 values and clinical neutropenia. When these values were obtained from other species, non-human primate and dog values compared well with human data, but rat and mouse IC50 values differed significantly. This suggests rodent assays may not accurately predict toxicity to the human hematopoietic system.