title: Thrombopoietin receptor agonists in primary immune thrombocytopenia.
abstract: Thrombopoietin (TPO) regulates thrombopoiesis through activation of TPO receptors on the megakaryocyte cell surface, resulting in increased platelet production. The TPO receptor agonists are novel treatments for patients with chronic ITP aimed at increasing platelet production through interactions with the TPO receptor on megakaryocytes. Two TPO receptor agonists, romiplostim and eltrombopag, have received regulatory approval. In patients with chronic ITP who remain at risk of bleeding following treatment with first-line therapies, these agents have been shown to increase platelet counts, decrease bleeding events, and reduce the need for adjunctive or rescue treatments. The TPO receptor agonists are well-tolerated, though uncertainty remains regarding the risk of thromboembolism and bone marrow fibrosis. Comparative clinical trial data addressing the efficacy, safety, cost-effectiveness, and impact on health-related quality of life of TPO receptor agonists relative to other second-line treatment options are needed to guide treatment decisions in chronic ITP patients who fail first-line therapies.
authors.affiliation: Division of Hematology and Thromboembolism, Department of Medicine, McMaster University, Hamilton, Ontario, Canada.
authors.forename: Deborah
authors.initials: D
authors.lastname: Siegal
authors.forename: Mark
authors.initials: M
authors.lastname: Crowther
authors.forename: Adam
authors.initials: A
authors.lastname: Cuker
mesh_terms: D001565:Benzoates / Q000494:pharmacology / Q000627:therapeutic use; D017326:Clinical Trials, Phase III as Topic; D006801:Humans; D006834:Hydrazines / Q000494:pharmacology / Q000627:therapeutic use; D011720:Pyrazoles / Q000494:pharmacology / Q000627:therapeutic use; D016032:Randomized Controlled Trials as Topic; D011961:Receptors, Fc / Q000627:therapeutic use; D053628:Receptors, Thrombopoietin / Q000819:agonists* / Q000276:immunology; D011993:Recombinant Fusion Proteins / Q000494:pharmacology / Q000627:therapeutic use; D013921:Thrombocytopenia / Q000188:drug therapy* / Q000276:immunology; D034061:Thrombopoiesis / Q000187:drug effects; D013926:Thrombopoietin / Q000494:pharmacology / Q000627:therapeutic use
chemical_list: D001565:Benzoates; D006834:Hydrazines; D011720:Pyrazoles; D011961:Receptors, Fc; D053628:Receptors, Thrombopoietin; D011993:Recombinant Fusion Proteins; D013926:Thrombopoietin; C488777:romiplostim; C520809:eltrombopag