Treatment patterns of thrombopoietin receptor agonists among adults with primary immune thrombocytopenia: A Korean nationwide population-based study
Introduction
Immune thrombocytopenia (ITP) is an acquired autoimmune disorder characterized by a low platelet count resulting from antibody-mediated platelet destruction and impaired platelet production of megakaryocytes depending on the degree of thrombocytopenia, with an increased risk of bleeding [1], [2].
For adult patients with newly diagnosed ITP, the guidelines recommend corticosteroids (CS), intravenous immunoglobulin (IVIg), and anti-D immunoglobulin (anti-D) as first-line treatments [3], [4]. However, as many as 80% of adult patients with ITP experience treatment failure with CS or become dependent on them and require a second-line therapy [5], [6]. According to the recent American Society of Hematology (ASH) ITP clinical guidelines, thrombopoietin receptor agonists (TPO-RAs) are highly recommended for adults with a ≥ 3-month history of ITP who are CS-dependent or who have no response to CS [4]. However, the choice of second-line therapy is based on patient values and priorities as well as available resources.
In Korea, newly diagnosed ITP patients receive CS and/or IVIg. When the first-line therapy is ineffective or intolerable for the patient, second-line treatment options include splenectomy, rituximab, and TPO-RAs. To date, rituximab is not covered by the Korean National Health Insurance System (NHIS) and is used at the patient's expense. TPO-RAs such as eltrombopag or romiplostim have been covered by the NHIS since March 2016 in Korea when used in treatment of adult patients with ITP relapse after splenectomy or patients who are refractory to CS and IVIg and for whom splenectomy is medically contraindicated. Despite an increase in TPO-RA treatment, the treatment pattern for TPO-RAs among adults with ITP is not well understood [7], [8], [9]. In this study, we aimed to investigate the nationwide practice patterns of TPO-RA use for ITP based on the Korean Health Insurance Review and Assessment Service databases.
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Data sources
The Health Insurance Review and Assessment Service (HIRA) is a government-affiliated organization that has received claims made by all medical institutions in Korea since 2000 [10]. HIRA databases are open for all investigators with academic purposes and include patient demographic information, diagnoses, procedures, and prescriptions obtained from inpatient and outpatient records of approximately 50 million Koreans.
This study was approved by the Institutional Review Board of Seoul National
Patient demographic and clinical characteristics
We identified 3885 patients with incident ITP during the four-year study period. Clinical characteristics of ITP patients are summarized in Table 1. Overall, the median age was 53 years, and 61.8% of patients were female. Of the total 3885 patients, 1745 (44.9%) required treatment for ITP, with a median follow-up duration of 31.4 months (range, 0.1–59.8 months). Patients undergoing treatment were older, more likely to be female, and more likely to have a high CCI score than those not receiving
Discussion
TPO-RAs are effective and well-tolerated treatment options for second-line ITP treatment. This study provides real-world data on treatment patterns, especially TPO-RAs, among adults with primary ITP in a nationally representative population being treated in a real-world clinical practice setting.
Consistent with previous studies [5], [12], [13], CS are the most commonly used therapy after diagnosis, reflecting their continued importance in the initial management of ITP. In this study, of all
Conclusion
This population-based study is one of the first to describe the treatment pattern of TPO-RAs for ITP patients in Korea. Considering the significant reduction in platelet transfusion among patients treated with TPO-RAs, especially those who were heavily pretreated, TPO-RAs seem to be a suitable therapeutic option in refractory cases. Further randomized and controlled clinical studies are warranted to provide a comprehensive and updated view of the evidence regarding medication safety and
Funding
This research was supported by the Seoul National University Bundang Hospital Research Fund (16-2017-006).
Declaration of competing interest
The authors have no conflicts of interest to declare regarding the content of this article.
Acknowledgments
The authors would like to thank the Big Data Division, Korean Health Insurance Review & Assessment Services, for data retrieval.
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