Haploidentical Stem Cell Transplantation after Myeloabaltive Conditioning Is a Valid and Safe Option for Young Patients with Refractory or Relapsed Aggressive Non-Hodgkin Lymphoma: A Study Compared with HLA-Matched Transplant

Purpose: The role of haploidentical hematopoietic stem cell transplantation (haplo-HSCT) therapy for refractory or relapsed (R/R) aggressive non-Hodgkin lymphoma (NHL) patients was still unknown. In this study, we aimed to explore the clinical outcome of R/R aggressive NHL patients received haplo-HSCT treatment. Patients and Methods: 23 R/R aggressive NHL patients who had undergone haplo-HSCT in our center between February 2006 and October 2015 were retrospectively analyzed, and 25 R/R aggressive NHL patients who received HLA-matched HSCT at the same period were also involved in this study. All patients received myeloablative conditioning (MAC) regimen, and antithymocyte globulin, cyclosporine A, mycophenolate mofetil and short course of methotrexate were used as graft-versus-host disease (GVHD) prophylaxis. 12 patients had experienced autologous HSCT prior to allo-HSCT. Results: The median age of the total 48 patients was 33 (16-58) years old, and there were 33 males and 15 females in the total cohorts. The diagonosis were as following: 16 (33%) diffuse large B cell lymphoma and 22 (46%) peripheral T cell lymphoma. There were no difference in sex, age at transplantation, histologic diagnosis, aaIPI score, previous ASCT and conditioning regime between HLA-matched HSCT and Haplo-hsct groups. 44 patients had achieved engrafment, and the median times to neutrophil and platelet recovery were 12 and 15 days, respectively. Incidences of grade 3-4 acute GVHD were 18.3% in haplo-HSCT group and 16.7% in HLA-matched HSCT groups(p=0.87), while 2 years cumulative incidences of chronic GVHD in these two groups were 43.5% and 36.7% (P=0.68). For 16 patients who had chemoresistant disease at transplantation in haplo-HSCT group, four patients achieved complete remission, and ten patients achieved partial remission, while the other two patients experienced disease progression at 21 days and 37 days, respectively. With a median follow-up of 25 months, 12 patients experienced disease recurrence or progression in haplo-HSCT. And four patients died of transplantation related mortality: infection (n=2); acute GVHD (n=1) and multi-organ failure (n=1). There were no differences in overall survival (OS) rate at 2 years (52.8% vs 57.0%, P=0.85) and 2 years progress free survival (PFS) rate (52.7% vs 56.9%, p=0.73) between the haplo-SCT and HLA-matched SCT groups. Multivariate analyses suggested that old age (>45 years)(p=0.02), primarychemorefractory (p=0.04)and occurrence of grade3-4 aGVHD (p=0.01) may contribute to poor prognosis. Conclusion: Haploidentical hematopoietic stem cell transplantation withmyeloablative conditioning regimenachieved satisfactory outcome with acceptable side-effects. This approachcan be a feasible and acceptabletherapy for young patients withR/R NHLwho have no access to a HLA-matched donor. Disclosures No relevant conflicts of interest to declare.