Comparison of Melphalan Dose in Patients with Myelodysplastic Syndrome Undergoing Allogeneic Transplantation with Reduced-Intensity Conditioning

The present study compared lower -dose melphalan (80 mg/m 2 , FM80) and higher -dose melphalan (140 mg/m 2 , FM140) when administering reduced -intensity conditioning with fludarabine in adult patients with myelodysplastic syndrome (MDS) undergoing allogeneic hematopoietic stem cell transplantation (allo-HSCT). We retrospectively analyzed nationwide registry data (2006 to 2019) and compared transplant outcomes between the 2 groups. Ninety-two patients (median age, 61 [interquartile range, 56 to 65] years) were assigned to the FM80 and FM140 groups by propensity score matching. The 3 -year overall survival (OS) rate in the FM140 group (63.9%; 95% con fidence interval [CI], 52.9% to 73.0%) was significantly higher than that in the FM80 group (54.2%; 95% CI, 37.1% to 52.1%) ( P = .038). The FM140 group had a nonsignificantly ( P = .095) lower 3year cumulative incidence of relapse (15.5%; 95% CI, 8.9% to 23.8% versus 26.0%; 95% CI, 17.3% to 35.5%). The 3 -year cumulative incidences of nonrelapse mortality were 22.3% (95% CI, 14.1% to 31.8%) and 23.7% (95% CI, 15.4% to 33.2%) in the FM80 and FM140 groups, respectively ( P = .49). The beneficial effect of FM140 was more evident in patients with a poor cytogenetic risk. Our findings suggest the superiority of FM140 in patients with MDS undergoing allo-HSCT, especially in high -risk patients. (c) 2024 The American Society for Transplantation and Cellular Therapy. Published by Elsevier Inc. All rights reserved.