Immune thrombocytopenia: Pathophysiology and impacts of Romiplostim treatment.

Immune thrombocytopenia (ITP) is an autoimmune bleeding disease caused by immune-mediated platelet destruction and decreased platelet production. ITP is characterized by an isolated thrombocytopenia (<100 × 109/L) and increased risk of bleeding. The disease has a complex pathophysiology wherein immune tolerance breakdown leads to platelet and megakaryocyte destruction. Therapeutics such as corticosteroids, intravenous immunoglobulins (IVIg), rituximab, and thrombopoietin receptor agonists (TPO-RAs) aim to increase platelet counts to prevent hemorrhage and increase quality of life. TPO-RAs act via stimulation of TPO receptors on megakaryocytes to directly stimulate platelet production. Romiplostim is a TPO-RA that has become a mainstay in the treatment of ITP. Treatment significantly increases megakaryocyte maturation and growth leading to improved platelet production and it has recently been shown to have additional immunomodulatory effects in treated patients. This review will highlight the complex pathophysiology of ITP and discuss the usage of Romiplostim in ITP and its ability to potentially immunomodulate autoimmunity.

Semple JW ，Schifferli A ，Cooper N ，Saad H ，Mytych DT ，Chea LS ，Newland A ... -  《-》

Romiplostim in chronic immune thrombocytopenic purpura.

Cersosimo RJ 《-》

Romiplostim in children with newly diagnosed or persistent primary immune thrombocytopenia.

Immune thrombocytopenia (ITP) is a disease of heterogenous origin characterized by low platelet counts and an increased bleeding tendency. Three disease phases have been described: newly diagnosed (≤ 3 months after diagnosis), persistent (> 3-12 months after diagnosis), and chronic (> 12 months after diagnosis). The majority of children with ITP have short-lived disease and will not need treatment. For children with newly diagnosed ITP, who have increased bleeding symptoms, short courses of steroids are recommended. In children who do not respond to first-line treatment or who become steroid dependent, thrombopoietin receptor agonists (TPO-RAs) are recommended because of their efficacy and safety profiles. In this narrative review, we evaluate the available evidence on the use of the TPO-RA romiplostim to treat children with newly diagnosed or persistent ITP and identify data from five clinical trials, five real-world studies, and a case report. While the data are more limited for children with newly diagnosed ITP than for persistent ITP, the collective body of evidence suggests that romiplostim is efficacious in increasing platelet counts in children with newly diagnosed or persistent ITP and may result in long-lasting treatment-free responses in some patients. Furthermore, romiplostim was found to be well tolerated in the identified studies. Collectively, the data suggest that earlier treatment with romiplostim may help children to avoid the side effects associated with corticosteroid use and reduce the need for subsequent treatment.

Grainger JD ，Kühne T ，Hippenmeyer J ，Cooper N ... -  《-》

The burden of immune thrombocytopenia in adults: evaluation of the thrombopoietin receptor agonist romiplostim.

Deuson R ，Danese M ，Mathias SD ，Schoonen M ，Fryzek J ... -  《-》

Thrombopoietin receptor agonists for preparing adult patients with immune thrombocytopenia to splenectomy: results of a retrospective, observational GIMEMA study.

In patients with immune thrombocytopenia (ITP) refractory to corticosteroids and intravenous immunoglobulins (IVIG), splenectomy may result at higher risk of peri-operative complications and, for this reason, potentially contraindicated. The thrombopoietin receptor agonists (TPO-RAs) romiplostim and eltrombopag have shown high therapeutic activity in primary ITP, but data of efficacy and safety regarding their use in preparation for splenectomy are missing. Thirty-one adult patients, median age 50 years, with corticosteroids and/or IVIG refractory persistent and chronic ITP who were treated with TPO-RAs (romiplostim= 24; eltrombopag= 7) with the aim to increase platelet count and allow a safer execution of splenectomy were retrospectively evaluated. Twenty-four patients (77%) responded to the use of TPO-RAs with a median platelet count that increased from 11 × 10(9) /L before starting TPO-RAs to 114 × 10(9) /L pre-splenectomy, but a concomitant treatment with corticosteroids and/or IVIG was required in 19 patients. Twenty-nine patients underwent splenectomy while two patients who responded to TPO-RAs subsequently refused surgery. Post-splenectomy complications were characterized by two Grade 3 thrombotic events (1 portal vein thrombosis in the patient with previous history of HCV hepatitis and 1 pulmonary embolism), with a platelet count at the time of thrombosis of 260 and 167 × 10(9) /L, respectively and one Grade 3 infectious event. TPO-RAs may represent a therapeutic option to improve platelet count and reduce the risk of peri-operative complications in ITP candidates to splenectomy. An increased risk of post-splenectomy thromboembolic events cannot be ruled out and thromboprophylaxis with low-molecular weight heparin is generally recommended.

Zaja F ，Barcellini W ，Cantoni S ，Carpenedo M ，Caparrotti G ，Carrai V ，Di Renzo N ，Santoro C ，Di Nicola M ，Veneri D ，Simonetti F ，Liberati AM ，Ferla V ，Paoloni F ，Crea E ，Volpetti S ，Tuniz E ，Fanin R ... -  《-》