Impact of conditioning regimen intensity on the outcomes of peripheral T-cell lymphoma, anaplastic large cell lymphoma and angioimmunoblastic T-cell lymphoma patients undergoing allogeneic transplant.

Abstract

There have been no large studies comparing reduced-intensity/non-myeloablative conditioning (RIC/NMA) to myeloablative conditioning (MAC) regimens in T-cell non-Hodgkin lymphoma (T-NHL) patients undergoing allogeneic transplant (allo-HCT). A total of 803 adults with peripheral T-cell lymphoma, anaplastic large cell lymphoma and angioimmunoblastic T-cell lymphoma (age 18-65years), undergoing allo-HCT between 2008-2019 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. There were no significant differences between the two cohorts in terms of patient sex, race and performance scores. Significantly more patients in the RIC/NMA cohort had peripheral blood grafts, haematopoietic cell transplantation-specific comorbidity index (HCT-CI) of ≥3 and chemosensitive disease compared to the MAC cohort. On multivariate analysis, overall survival (OS) was not significantly different in the RIC/NMA cohort compared to the MAC cohort (hazard ratio (HR)=1.01, 95% confidence interval (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 therapy failure (HR=1.14; 95% CI=0.92-1.41, p=0.23) were not significantly different between the two cohorts. Relative to MAC, RIC/NMA was associated with a significantly lower risk of grade 3-4 acute graft-versus-host disease (HR=0.67; 95% CI=0.46-0.99, p=0.04). Among chemorefractory patients, there was no difference in OS, therapy failure, relapse, or NRM between RIC/NMA and MAC regimens. In conclusion, we found no association between conditioning intensity and outcomes after allo-HCT for T-cell NHL.