More than just B-cell inhibition

Despite tremendous advances in the therapy of rheumatoid arthritis (RA), there remains interest in oral agents that may off er benefi ts that are similar to, or better than, those of biologic therapies. In their paper, Chang and colleagues demonstrate the eff ectiveness of a Bruton tyrosine kinase (Btk) inhibitor in two models of RA. Btk inhibition impacts several pathways aff ecting both B-cell and macrophage activation, making it a promising target in RA. However, other kinase inhibitors have failed to transition from animal models to human therapy, so it remains to be seen whether a Btk inhibitor will have a role in the RA treatment armamentarium.