Eltrombopag Enhances Recovery from Cytopenias Due to Poor Graft Function after Hematopoietic Cell Transplantation.

Introduction: Poor graft function (PrGF) is a serious complication of allogeneic hematopoietic cell transplantation (allo-HCT), and current therapies are only partially effective. Eight published reports on the effect of eltrombopag on PrGF showed encouraging results. This study aimed to assess the safety and efficacy of eltrombopag for the treatment of PrGF after allo-HCT.

Methods: A retrospective study was conducted on 23 patients with PrGF following allo-HCT at the King Hussein Cancer Center (KHCC), Amman, Jordan between January 2013 and December 2023. The patient-, disease-, and transplant-related characteristics were obtained from the KHCC-BMT database.

Results: The median age was 47 years (range, 26-68 years), and 13 patients were female. Fourteen patients received reduced-intensity conditioning, and 14 donors were human-leukocyte antigen (HLA) -identical siblings. Median hemoglobin (Hb) concentration pre-eltrombopag administration was 8.5 g/dL (range: 6-14.2 g/dL), granulocytes 7.1 × 10/L (range: 1.6-85 × 10/L), and platelets 18 × 10/L (range: 6-50 × 10/L). Thirteen patients had platelets < 20 × 10/L, and 15 had reduced megakaryocytes. The median CD34-positive cell dose was 6.10 × 10/kg (range: 2.75-9.78 × 10/kg). Eltrombopag was initiated at a median of 105 day (d) post-transplant (range: 29-800 d). The median weekly dose was 488 mg (range: 350-700 mg), and the median treatment duration was 75 d (range: 5-446 d). In total, 65% of patients (n=15) responded at a median of 30 d (range, 7-122 d). Twelve responders were alive at a median follow-up of 30 months (range: 7.0-122 months) with normal blood counts. The 2-year overall rate was 48% (95% confidence intervals, 27-70%), and seven non-responders died because of relapse. No major adverse events were reported.

Conclusion: Eltrombopag improved peripheral blood counts in patients with PrGF following allo-HCT. Thus, response to eltrombopag was predictable and has a significant effect on survival.