Therapeutics: Colony-stimulating factor 1 receptor (CSF1R; C-FMS; CD115)

Mouse studies suggest the CSF1R inhibitor PLX3397 could help treat brain injury-induced neuroinflammation. CSF1R is expressed only on microglial cells in the brain and induces their proliferation. In a mouse model of diphtheria toxin-induced hippocampal injury, PLX3397 decreased the number of microglia and expression of inflammatory genes and increased performance on memory tasks compared with no treatment. Next steps include determining concentrations and dosing schedules of the inhibitor that could be used in clinical trials.

Daiichi Sankyo Co. Ltd. has PLX3397, a small molecule inhibitor of CSF1R, stem cell factor (SCF) receptor tyrosine kinase (c-Kit; KIT; CD117) and FMS-like tyrosine kinase 3 (FLT3; CD135), in Phase II testing to treat acute myelogenous leukemia (AML), brain cancer, breast cancer, Hodgkin's lymphoma, melanoma and prostate cancer, and in Phase I testing to treat solid tumors...