Dual T-cell depletion with ATG and PTCy for peripheral blood reduced intensity conditioning allo-HSCT results in very low rates of GVHD.

The efficacy of posttransplant cyclophosphamide (PTCy) and antithymocyte globulin (ATG) in controlling GVHD has been previously reported. We aim to study the safety and efficacy of the use of dual T-cell depletion with ATG and PTCy for peripheral blood reduced intensity conditioning regimen allo-HSCT in 270 patients with hematological malignancies. Median follow-up was 12.7 months. Nineteen percent of patients received grafts from a matched related donor, 46% from 10/10 matched unrelated donors (MUD), 16% from 9/10 MUD and 19% from haploidentical donors. Graft failure rate was 9%. CMV and EBV reactivation rates were 58 and 64%. The cumulative incidence of grade II-IV and III-IV acute GVHD at day + 100 was 20.1% and 4.6%, respectively. The CI of moderate/severe chronic GVHD at 1 year was 12.4%. There were no differences in the incidence of GVHD according to donor type. One-year OS, RFS, NRM, CIR, and GVHD-free/RFS respectively were 65.2%, 56.9%, 22.7%, 20.3%, and 47.6%. Higher disease-risk index and worse Karnofsky performance status were significant factors for poor outcomes. In conclusion, the use of T-cell dual depletion with ATG and PTCy results in very low rates of acute and chronic GVHD and acceptable relapse rates and NRM.