p38R MAP kinase is a key anti-inflammatory target for rheumatoid arthritis, influencing biosynthesis of pro-inflammatory cytokines TNFR and IL-1β at a translational and transcriptional level. In this paper, we describe how we have optimized a series of novel p38R/β inhibitors using crystal structures of our inhibitors bound to p38R, classical medicinal chemistry, and modeling of virtual libraries to derive a molecule suitable for progression ...