A multi-centric study on the efficacy of eltrombopag in management of refractory chronic immune thrombocytopenia

Abstract

The aim of the present study was to evaluate the efficacy and safety of eltrombopag, an oral thrombopoietin receptor agonist, in patients with chronic immune thrombocytopenia (ITP).A total of 285 chronic ITP patients (187 women, 65.6%; 98 men, 34.4 %) followed-up in 55 centers were enrolled in this retrospective cohort. Response to treatment was assesed according to platelet count (/mm) and defined as complete (platelet count > 100.000/mm), partial (platelet count: 30.000-100.000/mm or doubling of platelet count after treatment), and unresponsive (< 30.000/mm). Clinical findings, descriptive features, response to treatment and side effects were collected. Correlations between descriptive, clinical and hematological parameters were analyzed.The median age at diagnosis was 43.9 ± 20.6 (3-95) years and the duration of follow-up was 18.0 ± 6.4 (6 to 28.2) months. Overall response rate was 86,7% (n=247). Complete and partial responses were observed in 182 (63.8 %) and 65 (22.8 %) patients, respectively. Thirty-eight patients (13.4 %) did not respond to eltrombopag treatment. For patients above 60 years old (n=68), overall response rate was 89,7% (n=61) and above 80 years old (n=12) overall response rate was 83% (n=10). Considering thrombocyte count before treatment, eltrombopag significantly increased platelet count at the 1, 2, 3, 4 and 8 weeks of treatment. As the time required for partial or complete response increased, response to treatment was significantly reduced. The time to reach the maximum platelet levels after treatment was quite variable (1-202 weeks). Notably, the higher the maximum platelet count after eltrombopag treatment, the more likely the side effects couldoccur. The most common side effects were headache (21.6 %), weakness (13.7 %), hepatotoxicity (11.8 %) and thrombosis (5,9%).Results of the current study imply that eltrombopag is an effective therapeutic option in even elderly patients with chronic ITP. However, patients must be closely monitored for response and side effects during treatment. Since both response and side effects may be variable throughout the follow-up period, patients should be evaluated dynamically, especially in terms of thrombosis risk factors.