Effectiveness and Optimal Dose of Eltrombopag in ITP: Real-World Single Site Study
Pisa Phiphitaporn, MD1, Nattiya Teawtrakul, MD1, Chinadol Wanitpongpun, MD1, Theerin Lanamtieng, MD1, Pornpim Tuntibundit, MD1
Affiliation : 1Division of Hematology, Department of Medicine, Srinagarind Hospital, Faculty of Medicine, Khon Kaen University, Khon Kaen, Thailand
Background: Immune thrombocytopenia (ITP) is an autoimmune condition characterized by low platelet counts caused by mechanisms such as antibody-mediated platelet destruction, impaired megakaryocyte production, and inadequate thrombopoietin levels. First-line corticosteroid treatment fails in a significant proportion of patients. Eltrombopag, a thrombopoietin receptor agonist (TPO-RA), is widely used in Thailand and supported by the Civil Servant Medical Benefits Scheme as a second-line treatment. While 50 mg/day is the standard dose in Western populations, studies in East Asia suggest that lower doses may be effective. This study aims to evaluate the effectiveness and safety of eltrombopag in Thai ITP patients, with a focus on dose optimization in real-world settings where clinical data are limited.
Objective: To evaluate the real-world effectiveness of eltrombopag and demonstrate the median time to response for each initial dose (25 mg/day and 50 mg/day) in the treatment of ITP.
Materials and Methods: This 5-year retrospective study analyzed adult ITP patients treated with eltrombopag. Data included patient characteristics, treatment responses, and adverse events. Descriptive statistics and Kaplan–Meier analysis with a log-rank test were used to compare the time to overall response between dose groups.
Results: A total of 25 patients (mean age 57.5 years, 68% female) were included. Eltrombopag was used as a second-line treatment in 72% of patients. The median time from diagnosis to treatment initiation was 280 days, and the mean baseline platelet count was 27.7×10³ mm³. Initial doses were 25 mg/day (52%) and 50 mg/day (48%). The best overall response rate was 92% (80% complete, 12% partial). Both groups had a favorable median time to response (21 vs. 26 days, p=0.92). Adverse events, including hepatitis and deep vein thrombosis, did not significantly differ between dose groups.
Conclusion: The present study confirms the effectiveness of eltrombopag in real-world treatment of ITP, with a high overall response rate. Both 25 mg/day and 50 mg/day initial doses were effective, suggesting that lower initial doses may be sufficient for Thai patients.
Keywords : Immune thrombocytopenia; Eltrombopag; Effectiveness; Initial dose
