Eltrombopag. Idiopathic thrombocytopenic purpura after treatment failure: romiplostim is a better option.

When corticosteroid therapy, immunoglobulin and splenectomy fail to control chronic idiopathic thrombocytopenic purpura and the risk of bleeding remains high, romiplostim is an acceptable option but close monitoring is needed to evaluate long-term risks. Eltrombopag (Revolade, GlaxoSmithKline) is a synthetic non-peptide agonist of endogenous receptors for thrombopoietin, a platelet growth factor. Clinical evaluation of eltrombopag in this setting is mainly based on a double-blind placebo-controlled trial in a heterogeneous group of 114 patients. The platelet count rose to at least 50,000/mm3 for five weeks in about one-quarter of patients receiving oral eltrombopag 50 mg/day. An indirect comparison providing weak evidence suggests that romiplostim is more effective. Clinical trials did not provide evidence that either drug reduced the frequency of bleeding. The haematological risks associated with eltrombopag are poorly evaluated, and mainly include: thrombosis, bone marrow disorders, and aggravation of thrombocytopenia after drug withdrawal. Aggravation of myelodysplastic syndrome cannot be ruled out in the long term. Hepatic disorders such as photosensitisation are frequent. The risk of cataract formation and renal impairment requires further study. There appears to be a high risk of pharmacokinetic interactions through a variety of mechanisms, including enzyme competition and cation binding, but this risk is not well documented. Eltrombopag is administered orally, making it more convenient than romiplostim, which necessitates weekly subcutaneous injections. In practice, when standard treatments fail in patients with chronic idiopathic thrombocytopenic purpura and a high risk of bleeding, it is better to use romiplostim, which appears to be somewhat more effective than eltrombopag. Eltrombopag also seems to carry a higher risk of non-haematological adverse effects and drug interactions.