Usefulness of thrombopoietin receptor agonists for persistent clinically-relevant thrombocytopenia after allogeneic stem cell transplantation.

Objective and MethodsSevere postengraftment thrombocytopenia is a common complication after allogeneic stem cell transplantation (alloSCT). A few studies have suggested that the use of thrombopoietin agonists (TPOa) may be useful in this setting. Our retrospective study is the largest series published to date; we retrospectively evaluated TPOa efficacy and safety in 20 adult alloSCT recipients who received TPOa as a compassionate use for clinically relevant thrombocytopenia. ResultsTwelve of 20 patients (60%) responded, with a 180-day cumulative incidence of successful platelet recovery to 30 and 50x10(9)/L of 57% (95% CI: 44%-71%) and 32% (95% CI: 18%-46%), respectively, which were reached at a median of 28 and 34days from the start of therapy. Fifty percent of the responders were able to discontinue the TPOa without recurrence of severe thrombocytopenia and its associated hemorrhagic complications. No serious adverse events were reported. Possible variables associated with higher response to TPOa were as follows: age<40years, presence of megakaryocytes in the bone marrow aspirate, and/or prior response to other hematopoietic growth factors. ConclusionThis study adds further enthusiasm for continued research on the use of these agents for the treatment of persistent thrombocytopenia in alloSCT recipients.