Eltrombopag Therapy in Children With Rare Disorders Associated With Thrombocytopenia.

Eltrombopag (ELT) is a thrombopoietin receptor activator that has shown efficacy in chronic immune thrombocytopenia. We report the outcome of ELT therapy in 4 children who were treated for rare hematological disorders, including Pearson syndrome, DiGeorge syndrome, posttransplant allogeneic poor graft function (PGF), and Wiskott-Aldrich syndrome. The ELT tolerance in the analyzed group was good, with the exception of the child with Pearson syndrome, who experienced an exacerbation of cataracts and had to discontinue treatment. Thromboembolic events were observed in one child, who continued ELT therapy despite achieving normalized platelet counts. Independence from PLT transfusions was observed at the 4-week timepoint of therapy in patients with DiGeorge syndrome and PGF who responded to ELT. Discontinuation of therapy was successful in one child, who sustained the normal CBC values afterward. In 2 patients, an increase in neutrophil counts was observed during ELT therapy without additional intervention, and a positive correlation between neutrophil and platelet values during ELT therapy was observed in the child with PGF. ELT is effective in rare pediatric disorders, but response patterns are determined by the underlying disease. ELT shows promising results in patients, but constitutional hematopoiesis defects reduce the chances of a response.