Abatacept
OrenciaRCSB PDB 3OSK · 3D model
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A lab-made fusion protein that steps into an immune handshake between cells, blocking the second signal T-cells need to fully switch on, calming the overactive immune response that drives joint inflammation.
How it works
Immune cells called T-cells need two separate go signals before they fully activate — one is like a key fitting a lock, the other is a secondary handshake that confirms the threat is real. Abatacept gets between the cells involved in that handshake and occupies the connection points, so the second signal never completes. Without full activation, T-cells stay in a lower-alert state instead of driving ongoing inflammation.
What it’s used for
Used to treat moderate-to-severe rheumatoid arthritis in adults, a similar form of joint arthritis in children and teens, and psoriatic arthritis in patients 2 and older. Also given alongside other medicines to help prevent a serious complication in patients undergoing certain stem cell transplants.
- Mechanism
- CTLA-4-Ig fusion protein (T-cell costimulation blocker)
- Drug class
- Fusion protein
- Therapeutic area
- Immunology