Use of Thrombopoietin Receptor Agonists in Prolonged Thrombocytopenia after Hematopoietic Stem Cell Transplantation

•Prolonged thrombocytopenia after hematopoietic stem cell transplantation (HSCT) is a strong risk factor for transplantation-related morbidity and mortality.•No common consensus exists for the uniform classification and management of prolonged thrombocytopenia after HSCT. The available literature inconsistently describes post-HSCT thrombocytopenia as either prolonged isolated thrombocytopenia (PIT) or secondary failure of platelet recovery (SFPR).•Thrombopoietin receptor agonists (eltrombopag and romiplostim) are being increasingly to treat patients with prolonged post-HSCT thrombocytopenia.•Our extensive literature review suggests that patients with prolonged post-HSCT thrombocytopenia may respond to both eltrombopag (overall response rate [ORR], 70%) and romiplostim (ORR, 82%), with no evidence of serious adverse effects.•However, the overall strength of evidence is weak in view of retrospective nature of the studies, lack of control groups, heterogeneity of data, and potential for publication bias. Prolonged thrombocytopenia after hematopoietic stem cell transplantation (HSCT) is a strong risk factor for transplantation-related morbidity and mortality, and no standard treatment guideline exists. Thrombopoietin receptor agonists (TPO-RAs), eltrombopag and romiplostim, increases the platelet production, and are being increasingly used in various conditions with thrombocytopenia. In this review, we present an overview of these TPO-RAs and review their efficacy and safety in prolonged post-HSCT thrombocytopenia. Through a systematic literature search, we identified 25 reports describing their use for this indication. Thirteen reports (8 case series and 5 case reports) described the use of eltrombopag in 78 patients with prolonged isolated thrombocytopenia (PIT) and 43 patients with secondary failure of platelet recovery (SFPR). A consistent and durable response with a rise in platelet counts >50 × 10 9/L for 7 consecutive days without platelet transfusion was seen in 85 of 121 patients (overall response rate [ORR], 70%). The responders included 56 patients with PIT (ORR for PIT, 72%) and 29 patients with SFPR (ORR for SFPR, 67%). No serious grade 3 or 4 adverse effects were reported. Similarly, 12 reports (6 case series and 6 case reports) described the use of romiplostim in prolonged post-HSCT thrombocytopenia (in 17 patients with PIT and 32 patients with SFPR). Response with the increment of platelet count was described in 40 out of 49 patients (ORR, 82%)