Sirolimus
RapamunePubChem CID 5284616 · 3D model
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Attaches to a helper protein inside cells and together they switch off mTOR, a signal that tells cells to grow and divide — calming an overactive immune system after a transplant and slowing abnormal cell growth in LAM.
How it works
Sirolimus works differently from most other anti-rejection drugs. Rather than blocking the first signal that switches on immune cells — the way cyclosporine and tacrolimus do — it latches onto a helper protein inside cells, and together they shut down mTOR, a protein that tells cells when to grow and divide. With mTOR turned off, the immune cells that would otherwise multiply to attack a transplanted organ are stopped before they can copy themselves.
What it’s used for
Sirolimus is approved to help prevent a transplanted kidney from being rejected by the body's immune system, usually given alongside other anti-rejection medicines. It's also approved on its own to treat lymphangioleiomyomatosis (LAM), a rare lung disease, by slowing the growth of abnormal cells in the lungs.
- Mechanism
- FKBP-12/mTOR inhibitor
- Drug class
- Small molecule
- Therapeutic area
- Transplant Immunology