Tofacitinib
XeljanzPubChem CID 9926791 · 3D model
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Blocks JAK enzymes inside immune cells that relay signals from inflammatory messenger proteins to the cell's nucleus, dialing down an overactive immune system's inflammatory activity.
How it works
Tofacitinib works by blocking JAK enzymes inside immune cells — enzymes that normally relay a 'turn up inflammation' signal from messenger proteins outside the cell to the cell's genetic machinery inside. By blocking that relay, tofacitinib dials down the overactive immune response that drives diseases like rheumatoid arthritis and ulcerative colitis.
What it’s used for
Tofacitinib is prescribed for several autoimmune and inflammatory conditions — rheumatoid arthritis, psoriatic arthritis, ankylosing spondylitis, a form of juvenile arthritis, and ulcerative colitis — generally only after a patient has already tried a TNF blocker (an older class of biologic drug) and it either didn't work well enough or couldn't be tolerated. It carries a boxed warning — the FDA's strongest safety warning — based on a large safety study in older rheumatoid arthritis patients with heart-related risk factors, which found higher rates, compared with TNF blockers, of serious infections, death, certain cancers, major heart problems, and blood clots.
- Mechanism
- JAK inhibitor, blocks cytokine signaling that drives inflammation
- Drug class
- Small molecule
- Therapeutic area
- Immunology