Outcome of Allogeneic Transplantation for Mature T-cell Lymphomas: Impact of Donor Source and Disease Characteristics.

Mature T-cell lymphomas constitute the most common indication of allogeneic hematopoietic cell transplantation (allo-HCT) in lymphomas. Large studies evaluating contemporary outcomes of allo-HCT in mature T-cell lymphomas, relative to commonly used donor sources are not available. Included in this registry study were adult patients who had undergone allo-HCT for anaplastic large cell lymphoma, angioimmunoblastic T-cell lymphoma (AITL), or peripheral T-cell lymphoma-NOS (PTCL-NOS) between 2008 and 2018. HCT platforms compared were post-transplant cyclophosphamide-based haploidentical (haplo-) HCT, matched sibling donor (MSD) HCT, matched unrelated donor HCT with in-vivo T-cell depletion (MUD TCD+), and MUD HCT without TCD (MUD TCD-). Co-primary endpoints were overall survival (OS) and progression-free survival (PFS); secondary endpoints included non-relapse mortality (NRM), and relapse/progression incidence (RI). 1942 patients were eligible (haplo-HCT 237; MSD 911; MUD-TCD+ 468; MUD TCD- 326). Cohorts were comparable for baseline characteristics except higher proportions of patients with decreased performance status (PS) and marrow graft recipients in the haplo-HCT group. On univariate and multivariate comparisons, OS and PFS, RI, and NRM were not significantly different between haplo-HCT, MSD, MUD-TCD+, and MUD-TCD- cohorts, with 3-year OS and PFS of 60%, 63%, 59%, and 64%; and 50%, 50%, 48%, and 52%, respectively. Significant predictors of inferior OS and PFS on multivariate analysis were active disease status at HCT and decreased PS. AITL was associated with significantly reduced relapse risk and better PFS compared to PTCL-NOS. Allo-HCT can provide durable PFS in patients with mature T-cell lymphoma. Outcomes of haplo-HCT were comparable to that of matched donor allo-HCT.