BIO-8169 is a selective inhibitor for interleukin receptor-associated kinase 4 ( IRAK 4 ), with an IC 50 of 0.23 nM. BIO-8169 exhibits good pharmacokinetic character, reduces the production of pro-inflammatory cytokines, and attenuates the autoimmune encephalomyelitis in EAE mice model. BIO-8169 exhibits good blood brain penetrant with a rat Kpu,u of 0.7.