Table.

The major drug classes that have been employed in the treatment or investigation of RA and that have been informative for pathogenesis studies are depicted herein.

Immune Target	Drugs	Key modes of action
TNF	Adalimumab Etanercept Golimumab Certolizumab Infliximab Biosimilars	Reduced endothelial, stromal cell & chondrocyte activation Reduced osteoclast differentiation/activation Modified cellular migration Reduced cytokine expression e.g. IL-6 Reduced metabolic/CVD risk
IL-6	Tocilizumab Multiple Ab in development	Reduced endothelial, stromal cell activation Reduced osteoclast activation Reduced cytokine/chemokine expression Altered lipid metabolism
Co-stimulation (CD28 - CD80/86)	Abatacept	Reduced T cell activation Diminished dendritic cell activation, cytokine production and antigen presentation Reduced osteoclast activation
B cell depletion (anti-CD20)	Rituximab	Depletion of CD20+ B cell lineages, sparing plasma cells. Reduced cytokine production Reduced antigen presentation
JAK inhibitors	Tofacitinib Baricitinib Multiple compounds in development	Inhibition of pivotal cytokine receptors with predictable downstream effects. JAK1, JAK2 and JAK3 thus far targeted
IL-1	Anakinra	Decreased endothelial cell, stromal cell activation Decreased cellular migration Altered T cell differentiation Innate immunity activation
Other cytokines (GM-CSF, IL-17, and others)	Multiple	Multiple