Eltrombopag for Treatment of Thrombocytopenia Following Hematopoietic Stem Cell Transplantation

Objective: This study aimed to evaluate the efficacy and safety of eltrombopag (ELT) in the treatment of thrombocytopenia following hematopoietic stem cell transplantation (HSCT). Materials and Methods: Forty-eight patients treated with ELT for thrombocytopenia after allogeneic or autologous transplantation at the Erciyes University Bone Marrow Transplantation Center between July 2017 and July 2021 were evaluated retrospectively. Results: Forty-eight HSCT recipients were included in this study. Thirty (62.5%) patients were evaluated as having experienced delayed platelet recovery (DPR) and 18 (37.5%) patients as having experienced secondary failure of platelet recovery (SFPR). The median platelet count before ELT treatment was 13x10(9)/L (range: 3-20x10(9)/L). Twentythree patients responded to treatment and the cumulative incidence of successful platelet recovery was 48%. Patients with both DPR and SFPR responded, but patients with DPR had a higher response rate (50% vs. 44%). The median platelet count of the 23 responding patients was 12x10(9)/L (5-19x10(9)/L) before treatment and 68x10(9)/L (52-266x10(9)/L) after treatment (p<0.0001). While the number of bone marrow megakaryocytes before treatment was adequate in 22 (46%) cases, it was decreased in 26 (54%) cases. Patients with adequate bone marrow megakaryocytes had a better response rate than those without (77% vs. 23%, p<0.0001). The group with adequate megakaryocytes responded to treatment at a median of 33 days (range: 9-174 days). Patients with decreased megakaryocytes responded at a median of 55 days (30-164 days) (p=0.002). No drug-related side effects were observed in any patients. Conclusion: This real-life experience demonstrates that ELT is an effective and safe treatment option for thrombocytopenia after HSCT. The adequacy of bone marrow megakaryocytes before ELT treatment was an important factor affecting response to treatment.