Edicotinib hydrochloride is a potent, selective, brain penetrant and orally active? colony-stimulating factor-1 receptor (CSF-1R) ?inhibitor with an IC 50 of 3.2 nM. Edicotinib hydrochloride exhibits less inhibitory effects on KIT and FLT3 with IC 50 values of 20 nM and 190 nM, respectively. Edicotinib hydrochloride limits microglial expansion and attenuates microglial proliferation and neurodegeneration?in mice. Edicotinib hydrochloride has the potential for Alzheimer’s disease and rheumatoid arthritis research.