Romiplostim

Romiplostim is a recombinant “peptibody”-type thrombopoietin receptor (TPO‑R, MPL) agonist, used for chronic immune thrombocytopenia, etc. It binds to TPO‑R on the surface of hematopoietic progenitor cells and mature megakaryocytes, activates pathways such as JAK2/STAT5, PI3K/AKT, and MAPK, promotes megakaryocyte proliferation, maturation, and terminal polyploidization, and increases peripheral platelet production. Unlike recombinant TPO, Romiplostim has an epitope different from endogenous TPO, reducing the risk of cross-immunoneutralization. Animal studies suggest that long-term high doses may induce bone marrow reticulin fibrosis, and monitoring is required.