There have been no substantial studies comparing reduced-intensity/non-myeloablative conditioning (RIC/NMA) to myeloablative conditioning (MAC) regimens in patients with T-cell non-Hodgkin lymphoma (T-NHL) receiving allogeneic transplant (allo-HCT). A total of 803 adults (age 18–65) with peripheral T-cell lymphoma, anaplastic large cell lymphoma, or angioimmunoblastic T-cell lymphoma who received allo-HCT between 2008 and 2019 and reported to the Center for International Blood and Marrow Transplant Research with either MAC (n=258) or RIC/NMA regimens (n=545) were evaluated. In terms of patient sex, race, and performance ratings, there were no significant variations between the two cohorts. When compared to the MAC cohort, the RIC/NMA group had significantly more patients with peripheral blood grafts, a haematopoietic cell transplantation-specific comorbidity index (HCT-CI) of 3, and chemosensitive illness. 

Overall survival (OS) was not substantially different in the RIC/NMA group compared to the MAC cohort on multivariate analysis (hazard ratio (HR)=1.01, 95% CI =0.79–1.29; P=0.95). Similarly, non-relapse mortality (NRM) (HR=0.85, 95% CI=0.61–1.19; P=0.34), risk of progression/relapse (HR=1.29; 95% CI=0.98–1.70; P=0.07), and treatment failure (HR = 1.14; 95% CI = 0.92–1.41, P=0.23) did not vary substantially between the two groups. RIC/NMA was associated with a substantially decreased risk of grade 3–4 acute graft-versus-host disease (HR=0.67; 95% CI=0.46–0.99, P=0.04) when compared to MAC. There was no difference in OS, treatment failure, recurrence, or NRM between the RIC/NMA and MAC regimens in chemorefractory patients. Finally, they discovered no link between training intensity and outcomes following allo-HCT for T-cell NHL.