The Impact of Eltrombopag Administration on the Clinical Course of Severe Refractory Fatal Acquired Aplastic Anemia

Severe aplastic anemia (SAA) has an aggressive clinical course and represents a “difficult-to-treat” situation with current medications [1]. Eltrombopag is a c-mpl receptor agonist oral thrombopoietin-mimetic drug, mainly active in immune thrombocytopenic purpura (ITP) [2]. Single-agent oral eltrombopag produced hematological responses in 11 of 25 cases of aplastic pancytopenia, with trilineage responses observed in some, suggesting a stimulatory effect of early myeloid progenitors in a pilot clinical trial [3]. We would like to share our experience with eltrombopag in 2 patients with SAA refractory to conventional immunosuppressive treatment. Since the thrombopoietin/c-mpl receptor system is present in early hematopoiesis and in hematopoietic stem cells (HSCs) [4], SAA is an area of potential clinical application for thrombopoietin receptor agonists, including eltrombopag [5]. A 19-year-old male patient was admitted to our emergency room with the complaints of nasal bleeding and ecchymosis. His medical history was unremarkable. On physical examination, the patient was appropriately alert and oriented, and no abnormality was detected except for mucosal petechial hemorrhages and ecchymosis. Laboratory studies revealed pancytopenia with Hb of 6.4 g/dL, leukocyte count of 1.5x109/L, platelet count of 4x109/L, and reticulocyte count of 0.2%. His absolute neutrophil count was 0.5x109/L. His coagulation profile was normal. The peripheral blood smear was consistent with the complete blood count, without any morphological abnormalities. Additionally, immunologic and virology tests were carried out, revealing no abnormality. He had a negative DEB test. We did not perform molecular genetic analysis tests for DKC1, TERC, or TINF2 because they are not available at our center.