Reduced intensity allogeneic stem cell transplant with anti-thymocyte globulin and post-transplant cyclophosphamide in acute myeloid leukemia

Objectives We aimed to study the efficacy of reduced intensity conditioning (RIC) allo-HSCT combined with anti-thymocyte globulin (ATG) and post-transplant cyclophosphamide (PTCy) for graft-versus-host disease (GVHD) prophylaxis in AML. Methods One hundred forty-seven patients were included. All patients underwent unmanipulated peripheral blood stem cell RIC allo-HSCT. Median follow-up was 12.8 months (range 0.5-39). Results Median age was 58 years. Twenty-nine (20%) recipients received 10/10 MRD grafts, 69 (47%) 10/10 MUD grafts, 20 (13.6%) 9/10 MMUD, and 29 (20%) haploidentical grafts. The cumulative incidence of grade II-IV and III-IV acute GVHD at day +100, and moderate/severe chronic GVHD at 1-year were as follow: 14.3%, 1.4%, and 8.3%. There were no significant differences according to donor type (P = .46) and cumulative incidence of GVHD. One-year overall survival (OS), relapse-free survival (RFS), non-relapse mortality, and GVHD-free/Relapse-free survival were as follows: 66.9% (95% CI 58.4-74), 59.9%, and 18.7% and 53.7%. KPS <= 80 was predictive of worst OS (P = .04). Those recipients who received MUD transplants had better RFS (P = .01). Conclusions RIC allo-HSCT combined with ATG and PTCy is safe and a potentially curative strategy and it is associated with impressive GRFS in AML.