Allogeneic stem cell transplantation using lymphoablative rather than myeloablative conditioning regimen for relapsed or refractory lymphomas

In relapsed or refractory non-Hodgkin lymphoma (NHL), allogeneic hematopoietic stem cell transplantation (allo-HSCT) provides graft-versus-lymphoma activity resulting in fewer incidences of relapse. However, therapy-related mortality (TRM) remains an important challenge. We attempted to introduce our reduced-intensity conditioning (RIC) regimen. From 2007 to 2013, we treated 28 relapsed or refractory NHLs with allo-HSCT. All were pre-conditioned with fludarabine [FLU, 180 mg/body surface area (BSA)/6 days] and melphalan (MEL, 70 mg/BSA/1 day); 25 (all but 3) were additionally treated with total body irradiation (TBI, 800 cGy/4Fx/2 days). Peripheral blood stem cells were collected from matched siblings (n = 10) or suitably matched unrelated (n = 18) donors. There were eight diffuse large B-cell lymphomas, seven peripheral T-cell lymphoma not otherwise specified, give lymphoblastic lymphomas, two mantle cell lymphomas, and six various other lymphomas. Of these patients, 10 relapsed after auto-HSCT, 5 relapsed after chemotherapy, and 13 were refractory lymphomas. After allo-HSCT, complete remission was achieved in 22 (78.5%) patients. After a median follow-up of 24.8 months, 3-year overall survival and disease-free survival were 62.4 and 59.2% and the 3-year TRM and relapse incidence were 14.9 and 28.6% respectively. Acute and chronic graft-versus-host diseases (GVHDs) were identified in 17 (≥Grade II in 12 patients) and 18 patients respectively, and the group with chronic GVHD showed favourable survival outcomes. In relapsed or refractory NHL, RIC-allo-HSCT using FLU+MEL+ 800 cGy TBI showed favourable survival outcomes with acceptable TRM and relapse incidence.