Sirolimus protein-bound particles (Fyarro)

Mechanism of action

From the NCI Drug Dictionary: The macrolide antibiotic rapamycin bound to nanoparticle albumin with immunosuppressant (see sirolimus) and potential antiangiogenic and antineoplastic activities. Rapamycin binds to the immunophilin FK Binding Protein-12 (FKBP-12) to generate a complex that binds to and inhibits the activation of the mammalian Target Of Rapamycin (mTOR), a key regulatory kinase. In turn, inhibition of mTOR may result in the inhibition of the phosphatidylinositol 3 (PI-3) kinase/Akt pathway and vascular endothelial cell growth factor (VEGF) secretion, which may result in decreased tumor cell proliferation and tumor angiogenesis. The binding of water-insoluble rapamycin to nanoparticle albumin permits the albumin-mediated endocytosis of rapamycin by tumor cells and endothelial cells.

Diseases for which it is used

• PEComa

History of changes in FDA indication

• 11/22/2021: Approved for adult patients with locally advanced unresectable or metastatic malignant perivascular epithelioid cell tumor (PEComa). (Based on AMPECT)

Also known as

• Code name: ABI-009
• Generic names: nab-Rapamycin, nab-Sirolimus
• Brand name: Fyarro