Eltrombopag for Inherited Thrombocytopenias

Inherited thrombocytopenias (ITs) are a heterogeneous group of disorders characterized by a reduced number of blood platelets and a consequent bleeding tendency that ranges from mild to life-threatening. Thrombocytopenia is caused by genetic mutations and therefore is present throughout life and can be transmitted to the progeny. Some patients with severely reduced platelet count present spontaneous bleeding, which represents a major clinical problem: in fact, bleeding diathesis exposes these subjects to the risk of severe hemorrhages, affects their quality of life and often requires hospitalization and/or transfusions. Conversely, other patients with ITs have absent or mild spontaneous bleeding tendency. However, even these patients are at risk of major bleeding on the occasion of surgery or other invasive procedures. Therefore, the potential for hemorrhages on the occasion of invasive procedures represent a clinical problem for all patients affected by ITs. Eltrombopag is a drug, available in tablets, which stimulates the production of platelets by the bone marrow. A previous study demonstrated that a short course of eltrombopag was effective in increasing platelet count in most patients with the MYH9-related disease (MYH9-RD), the most frequent form of IT. Eltrombopag was given for 3 to 6 weeks to 12 patients with MYH9-RD and platelet counts lower than 50 x10e9/L. Eleven patients responded to the drug and 8 of them obtained platelet counts higher than 100 x10e9/L or three times the baseline value. Remission of spontaneous bleeding was achieved by 8 of 10 patients and treatment was well tolerated in all the cases. Based on these findings, short-term eltrombopag courses have been successfully used for preparing for major surgery two patients with MYH9-RD and less than 20 x10e9 platelets/L. The present study has two main objectives. - To verify if eltrombopag is effective in transiently increasing platelet count over 100 x 10e9/L and abolishing bleeding tendency i