Real world evidence on drug utilization patterns of eltrombopag in adult patients with immune thrombocytopenia: Revieu (revolade™ [eltrombopag] in selected countries in the european union) study

Background: Immune thrombocytopenia (ITP) is an autoimmune disorder characterized by isolated thrombocytopenia, with platelet counts <100 × 109/L. Eltrombopag is an oral small-molecule nonpeptide thrombopoietin-receptor agonist that has shown to increase platelet production. It is approved for the management of patients with chronic ITP (aged ≥1 year) who are refractory to other treatments (eg, corticosteroids, immunoglobulins). The recommended eltrombopag dose in patients with chronic ITP is 25mg once daily, OD (East Asians, 12.5mg OD or 25mg every other day) in pediatrics aged 1-5 years, and 50mg OD (East Asians, 25mg OD) in adults and pediatrics aged 6-17 years at initiation, followed by dose adjustment to a maximum of 75mg OD based on platelet counts. REVIEU study was conducted in accordance with risk management plan in five European Union (EU) countries to document eltrombopag utilization patterns in real-world practice. Here, we report the eltrombopag data on the subset of adult patients (aged ≥18 years) with ITP as primary diagnosis. Aims: To evaluate the real-world data to determine drug utilization patterns among adult patients with ITP receiving eltrombopag within five EU countries. Methods: REVIEU study was a multinational, multicenter, retrospective, medical chart review in patients with a documented past treatment with eltrombopag between the period immediately after first approval/launch in May 2010 and September 2014 (ie, dispensed at least once by the pharmacy and patient received at least one dose) for whatever reason. Patients who participated or were participating in a randomized eltrombopag clinical trial were excluded.(Table Presented) Results: Overall, 287 adult patients with ITP (chronic [>12 months], 75.3%; persistent [3-12 months], 10.8%; acute [<3 months], 13.6%; unknown [n=1]) were included, majority in Spain (n=128) followed by Italy (n=67), Greece (n=36), France (n=29), and Germany (n=27). Eltrombopag was the first treatment with no prior ITP therapies in 12 (4.2%) [acute, 10.3%; persistent, 6.5%; chronic, 2.8%] patients. A total of 99 (34.6%) patients received one prior therapy (corticosteroids, 79 [27.6%]), 128 (44.8%) patients received two prior therapies (corticosteroids+immunoglobulin, 114 [39.9%]), and 47 (16.4%) patients received three prior therapies (corticosteroids, immunoglobulins, and splenectomy). In total, the majority of patients received at least one prescription of corticosteroids (252, 88.1%) followed by immunoglobulins (180, 62.9%), and splenectomy (64, 22.4%) prior to eltrombopag initiation. Patients received an average daily dose of eltrombopag 45.6mg (chronic ITP, 44.6mg; persistent ITP, 43.1mg; acute ITP, 53.0mg) during the study. Overall, dose changes were reported in 749 adult ITP prescriptions (down-titration, 53.7%; up-titration, 43.7%; no change in dose, 2.7%). 49.1% of dose changes were reported during the first 6 months of treatment (35% in first 3 months). The main reasons for dose change included: disease improvement (30.4%), no treatment response (26.8%) and others (27.1%). Disease improvement accounted for down-titration in 51.2% (206/402) and up-titration in 4.6% (15/327), and no treatment response for up-titration in 54.4% (178/327) and down-titration in 5.0% (20/402) of adult patients with ITP. Proportion of patients with platelet counts by ITP disease phase, and by eltrombopag dose are reported in Table 1. Summary/Conclusions: The majority of adult patients with ITP (75.3%) were diagnosed with chronic ITP, and were treated with eltrombopag as second-line or greater therapy after corticosteroids and immunoglobulins, in line with the approved indication. Eltrombopag was also prescribed in 24.4% of adult patients with acute and persistent ITP. The starting dose followed the summary of product characteristics (SmPC) recommendations in the majority of cases and dose modifications were generally according to platelet counts. Data from REVIEU study have shown that eltrombopag use in the real world setting is largely consistent with the EU label and is considered part of ITP medical therapies.