Watch this instructional video to learn how Nplate® works.
Nplate®, a TPO receptor agonist, is an Fc-peptide fusion protein (peptibody) that contains 2 single-chain subunits, each having a region with 2 TPO receptor-binding domains.1
Nplate® has no amino acid sequence homology to eTPO.1 As with all therapeutic proteins, patients may develop antibodies to the therapeutic protein. In clinical studies of patients with ITP, the incidence of binding antibody development during treatment with Nplate® or a non-US-approved romiplostim product was 4% (50/1112). Of the patients with positive antibodies who developed to romiplostim or to TPO, 5 patients had neutralizing activity to romiplostim and none had neutralizing activity to TPO. No apparent correlation was observed between antibody activity and clinical effectiveness or safety.1,4
In normal thrombopoiesis
In adult ITP, treated with Nplate®
eTPO induces platelet production by binding at the TPO receptor, also known as c-MPL, on megakaryocytes.3
Nplate® binds to the TPO receptor, activating the same signaling pathways as eTPO, resulting in megakaryocyte and platelet development.1
Nplate®, a TPO mimetic, increases platelet production and can outpace platelet destruction in ITP.1,2
ITP, immune thrombocytopenia.
Nplate® administration may increase the risk for development or progression of reticulin fiber formation within the bone marrow. This formation may improve upon discontinuation of Nplate®. In a clinical trial, one patient with ITP and hemolytic anemia developed marrow fibrosis with collagen during Nplate® therapy.
Nplate® is a thrombopoietin receptor agonist indicated for the treatment of thrombocytopenia in adult patients with immune thrombocytopenia (ITP) who have had an insufficient response to corticosteroids, immunoglobulins, or splenectomy. Nplate® is indicated for the treatment of thrombocytopenia in pediatric patients 1 year of age and older with ITP for at least 6 months who have had an insufficient response to corticosteroids, immunoglobulins, or splenectomy.
Nplate® is not indicated for the treatment of thrombocytopenia due to myelodysplastic syndrome (MDS) or any cause of thrombocytopenia other than ITP. Nplate® should be used only in patients with ITP whose degree of thrombocytopenia and clinical condition increase the risk for bleeding. Nplate® should not be used in an attempt to normalize platelet counts.
References: 1. Nplate® (romiplostim) prescribing information, Amgen. 2. Gernsheimer TB, George JN, Aledort LM, et al. Evaluation of bleeding and thrombotic events during long-term use of romiplostim in patients with chronic immune thrombocytopenia (ITP). J Thromb Haemost. 2009;8(6):1372-1382. 3. Kaushansky K. The molecular mechanisms that control thrombopoiesis. J Clin Invest. 2005;115(12):3339-3347. 4. Kuter DJ, Bussel JB, Newland A. Long-term treatment with romiplostim in patients with chronic immune thrombocytopenia: safety and efficacy. Br J Haematol. 2013;161(3):411-423.