Umirolimus

Umirolimus is a semi-synthetic macrocyclic lactone and a derivative of rapamycin that has immunosuppressive and anti-inflammatory effects. It halts the cell cycle at the G1 phase through an IL-2/mTOR-mediated pathway and inhibits proliferation of human smooth muscle cells. In a porcine overstretch model, coronary stents containing umirolimus for localized delivery to the vessel wall reduced stenosis by 50% and led to less thickening of the vessel wall than a bare metal stent. Rapamycin, and likely its derivatives, binds to the cytosolic FK-binding protein 12 (FKBP12) to inhibit the mammalian target of rapamycin (mTOR) pathway. Formulations containing umirolimus have been used in coronary stents for localized delivery to the vessel wall.