EBMT 2018 | Comparison of safety outcomes between PTCy-based haploidentical and HLA-matched related or unrelated donor transplantation for patients with R/R aggressive NHL

An oral session on lymphoma took place at the 44^th European Society for Blood and Marrow Transplantation (EBMT) annual meeting on 19 March 2018. Abstract OS1-2 was presented by Sarah Haebe, from the Department of Medicine III, Laboratory for Experimental Leukemia and Lymphoma Research, Ludwig-Maximilians University, Munich, Germany which compared the safety and efficacy of post-transplantation cyclophosphamide (PTCy)-based haploidentical donor (haplo-D) transplantation versus HLA-matched related donor (MRD) or unrelated donor (URD) transplantation in refractory or relapsed (R/R) aggressive non-Hodgkin lymphoma (aNHL).

In this study, patients treated with T-cell replete (TCR) HLA-haploidentical hematopoietic stem cell transplantation (haplo-HSCT) were matched-paired with patients receiving HLA-matched transplantation (MRD and URD). The age (± 5 years) and the stage at HSCT (defined as complete response [CR] or non-CR) varied between pair-matched patients in this analysis. The primary endpoints of this study were overall survival (OS), progression-free survival (PFS), non-relapse mortality (NRM) and graft-versus-host disease (GvHD) incidence.

Demographics

• N = 21 patients in each group (TCR/PTCy haplo-HSCT, MRD and URD)
• Successful match-pair single center analysis of 21 haplo-HSCT with 21 MRD and 21 URD patients
• Median age of all patients (range): 48 (20–65)
• Histology (all patients):
  • Aggressive NHL: 62%
  • Indolent NHL: 22%
  • T-cell NHL (T-NHL): 16%
• Median number of prior therapies (range): 4 (2–6)
• Conditioning regimen (all patients):
  • Reduced intensity conditioning (RIC): 58%
  • Non-myeloablative conditioning(NMA): 21%
  • Myeloablative conditioning (MAC): 21%

Key Findings

• Median follow-up: 39 months
• CR at Day +30 (all patients) = 84%;
• Median time to engraftment (days; P = 0.2):
  • MRD = 16
  • URD = 18
  • Haplo = 20
• PFS and OS at 2-years (%):
  • MRD = 33 and 43
  • URD = 19 and 38
  • Haplo = 43 and 52
• PFS and OS at 3-years (%):
  • MRD = 29 and 33
  • URD = 19 and 38
  • Haplo = 38 and 52
• Occurrence of acute GvHD II–IV at 100-days follow-up (%; P = 0.03):
  • MRD = 30
  • URD = 55
  • Haplo = 21
• Occurrence of chronic GvHD (moderate and severe) at one year follow-up (%; P = 0.4):
  • MRD = 39
  • URD = 35
  • Haplo = 20
• Non-relapse mortality (NRM) within one year after transplantation (%):
  • MRD = 2
  • URD = 33
  • Haplo = 24
• Relapse rate within the first year after transplantation (%):
  • MRD = 29
  • URD = 38
  • Haplo = 24
• Death from aplasia = 6 patients

The results from this study demonstrated similar outcomes between patients treated with haplo-HSCT using PTCy and patients who received HLA-matched transplantation. With a higher incidence of acute GvHD and NRM rates after URD transplantation, the authors suggested that haplo-HSCT might be used as an efficient safer alternative regimen for patients with aNHL.