XELJANZ/XELJANZ XR is the first in a new class of treatments for moderate to severe RA called Janus kinase (JAK) inhibitors. JAK inhibitors work deep inside the cell to disrupt cellular activities that occur in signaling pathways, known as the JAK pathways.

Learn more about the different treatment options and where XELJANZ fits into the mix.

What is a JAK inhibitor and why does it matter for me?