339P - A comparison of survival of patients with relapsed or refractory diffuse large B cell lymphoma undergoing allogeneic stem cell transplantation or receiving CAR-T therapy

Background

The advent of chimeric antigen receptor T cell (CAR-T) therapy has improved the outcomes of many patients with diffuse large B-cell lymphoma (DLBCL). However, it remains unknown whether allogeneic stem cell transplantation (allo-SCT) or CAR-T therapy is better for patients with relapsed/refractory (r/r) DLBCL. We thus retrospectively analyzed the effects of both therapies on the outcomes of r/r DLBCL patients treated at a single institute.

Methods

The medical records of 47 patients treated with tisagenlecleucel (tisa-cel) and 25 who underwent allo-SCT between January 1 2000 and May 31 2023 at Okayama University Hospital were retrospectively reviewed. The primary endpoint was 1-year overall survival (OS). The secondary endpoints included 1-year progression-free survival (PFS), non-relapse mortality (NRM), and the response rate (complete or partial). Data on both groups were subjected to multivariate analysis. Disease was considered to be chemosensitive if at least a partial response was achieved, and chemorefractory if the disease was stable or progressed after the last course of chemotherapy.

Results

There were no between-group differences in age, sex, disease stage, the International Prognostic Index, the number of prior chemotherapies, or central nervous system or disease status. The 1-year OS and PFS of the tisa-cel group were significantly better than those of the allo-SCT group (62.3% vs. 20%; p = 0.0003, 47.3% vs. 12%, p = 0.01 respectively). No significant between-group differences in the response rate were observed (tisa-cel group 72% vs. allo-SCT group; 60%, p = 0.3). NRM was significantly lower in the tisa-cel group (no deaths vs. 46%, p = 0.00002). In multivariate analysis of all r/r DLBCL patients, tisa-cel was associated with a favorable 1-year OS (hazard ratio [HR] 0.32, range 0.17 to 0.61, p = 0.0004) and chemorefractory status was associated with a poor 1-year OS (HR 3.94, range 1.73 to 8.97, p = 0.001).

Conclusions

The OS and NRM of the tisa-cel group were significantly superior to those of the allo-SCT group. Thus, CAR-T therapy may be more effective and less toxic than allo-SCT in patients with r/r DLBCL.

Clinical trial identification

Editorial acknowledgement

Legal entity responsible for the study

The authors.

Funding

Has not received any funding.

Disclosure

All authors have declared no conflicts of interest.