PLX5622 (free base)

PLX5622 is an inhibitor of colony-stimulating factor 1 receptor (CSF1R) tyrosine kinase with a Ki of 5.9 nM. It causes sustained and specific elimination of microglia. As a result of microglial depletion, plaques fail to form in the parenchymal space in the 5xFAD mouse model of Alzheimer’s disease (AD). Inhibition of the CSF1R at lower doses in 3xTg-AD mice prevents microglial association with plaques and improves cognition.