Post-Transplant Cyclophosphamide-Based GVHD Prophylaxis After Peripheral Blood Stem Cell HLA Identical Transplantation in Patients with Lymphoma: A Prospective Observational Study

Allogeneic stem cell transplantation (allo-SCT) from HLA-identical donors (HLAid) could be an effective salvage treatment for relapsed/refractory lymphoma. In this setting, standard graft-versus-host disease (GVHD) prophylaxis is based on cyclosporine and methotrexate, with the addition of anti-thymocyte globulin, at least for matched, unrelated donors. Promising data using post-transplant cyclophosphamide (PT-Cy) have been reported from retrospective studies in patients receiving allo-SCT from HLAid donors. Here, we report the results of a single-center, prospective observational study exploring the main outcomes of GVHD prophylaxis based on PT-Cy in 27 patients receiving HLAid donor transplantation for relapsed/refractory lymphoma. With a median follow-up of 38 months, 3-year GVHD-relapse-free survival and PFS and OS were 70.4%, 81.5%, and 88.9%, respectively. The 1-year cumulative incidence (CI) of non-relapse mortality (NRM) was 7.4%. The 6-month CI of acute GVHD was 7.4%, and the 1-year CI of extensive chronic GVHD was 7.7%, with no grade IV GVHD events or deaths from GVHD. Relapse was reported in three patients (1-year relapse incidence: 11%), and two died of progressive disease. No graft failure was observed. This study shows that PT-Cy may be an effective strategy to prevent GVHD in patients with lymphoma receiving HLAid transplantation. It is associated with low NRM and reasonable disease control.