Eltrombopag for Post-Transplantation Thrombocytopenia: Results of Phase II Randomized, Double-Blind, Placebo-Controlled Trial

Prolonged thrombocytopenia occurs in up to 37% of patients after hematopoietic stem cell transplantation (HSCT) and is associated with adverse prognosis and increased risk of bleeding. Eltrombopag, a thrombopoietin receptor agonist, can increase platelet counts in thrombocytopenic patients. We conducted a phase II study, adaptively randomizing patients at >= 35 days post-HSCT to receive placebo or eltrombopag at a platelet count <= 20,000/mu L for 7 days or platelet transfusion-dependent and a neutrophil count >= 1500/mu L. Sixty patients were randomized to eltrombopag (n = 42) or placebo (n = 18) and received at least 1 dose. Fifteen patients (36%) in the eltrombopag arm achieved a platelet count of >= 30,000/mu L, compared with 5 patients (28%) in the placebo arm, with a posterior probability of 0.75. (The protocol required this probability to be >0.975 to declare a winner; thus, the results are inconclusive.) However, 9 patients (21%) in the eltrombopag arm achieved a platelet count of >= 50,000/mu L, compared with no patients in the placebo arm (P = .046). The overall survival, progression-free survival, relapse rate, and nonrelapse mortality were similar in the 2 arms. In conclusion, compared with placebo, treatment with eltrombopag led to a higher percentage of patients achieving a platelet count of >= 50,000/mu L in patients with persistent thrombocytopenia after HSCT. (C) 2021 The American Society for Transplantation and Cellular Therapy. Published by Elsevier Inc. All rights reserved.