Eltrombopag: a review of its use in the treatment of thrombocytopenia in patients with chronic hepatitis C.

Eltrombopag (Revolade(®); Promacta(®)) is an orally bioavailable, small-molecule, thrombopoietin receptor agonist that selectively binds to thrombopoietin receptors on megakaryocyte precursors and megakaryocytes leading to increased platelet production. It is approved in a number of countries for the treatment of thrombocytopenia, including adult patients with chronic hepatitis C virus (HCV) infection to allow for the initiation and maintenance of peginterferon-based therapy, which is the focus of this review. In two, well-designed, randomized controlled trials in adults with chronic HCV infection and thrombocytopenia (ENABLE-1 and ENABLE-2), eltrombopag increased platelet counts to sufficient levels to allow for the initiation of peginterferon-based antiviral therapy in 95 % of patients whose baseline platelet counts would have made them ineligible or marginal candidates for peginterferon therapy. Moreover, a significantly higher proportion of eltrombopag recipients than placebo recipients achieved a sustained virological response (primary endpoint) 24 weeks after the completion of antiviral therapy. Of note, the additional benefit over placebo was relatively small (<10 %). Compared with placebo, eltrombopag was associated with fewer patients discontinuing antiviral therapy early and a numerically greater proportion of patients not requiring antiviral dose reduction. Oral eltrombopag had an acceptable tolerability profile; however, there is an increased risk of adverse events, including potentially fatal hepatic decompensation and thromboembolic events. Eltrombopag provides a new treatment option for thrombocytopenia in patients with chronic HCV infection to allow for optimal antiviral therapy.