Autologous Transplant versus Chimeric Antigen Receptor T-cell Therapy for Relapsed DLBCL in Partial Remission.

Abstract Background The relative efficacy of autologous hematopoietic cell transplant (auto-HCT) versus chimeric antigen receptor T-cell (CAR-T) therapy in diffuse large B-cell lymphoma (DLBCL) patients who achieve a partial remission (PR) after salvage chemotherapy is not known. Methods Using the Center for International Blood & Marrow Transplant Research registry database, we identified adult DLBCL patients who received either an auto-HCT (2013-2019) or CAR-T treatment with axicabtagene ciloleucel (2018-2019) while in a PR by CT or PET scan. We compared the clinical outcomes between the two cohorts using univariable and multivariable regression models after adjustment for relevant baseline and clinical factors. Results In the univariable analysis, the 2-year progression-free survival (52% vs. 42%; p=0.1) and the rate of 100-day non-relapse mortality (4% vs. 2%; p=0.3) were not different between the 2 cohorts but consolidation with auto-HCT was associated with a lower rate of relapse/progression (40% vs. 53%; p=0.05) and a superior overall survival (OS) (69% vs. 47%; p=0.004) at 2-years. In the multivariable regression analysis, treatment with auto-HCT was associated with a significantly lower risk of relapse/progression rate (HR=1.49; p=0.01) and a superior OS (HR=1.63; p=0.008). Conclusions In patients with DLBCL in a PR after salvage therapy, treatment with auto-HCT was associated with a lower incidence of relapse and a superior OS compared with CAR-T. These data support the role of auto-HCT as the standard-of-care in transplant-eligible patients with relapsed DLBCL in PR after salvage therapy.