Allogeneic Hematopoietic Cell Transplant for B-Cell Lymphomas in the Era of Novel Cellular Therapies: Experience from a Tertiary Canadian Center.

BACKGROUND

Allogeneic hematopoietic cell transplant (alloHCT) is a curative option for relapsed/refractory B-cell lymphomas (BCLs), but its role in the evolving field of cellular therapy is increasingly unclear as recent advances in transplant procedures have improved outcomes.

METHODS

This retrospective, single-center study included 55 BCL patients (large B-cell lymphoma-LBCL; indolent BCL; and mantle cell lymphoma-MCL) treated with alloHCT from 2015 to 2023 at Hôpital Maisonneuve-Rosemont. Primary endpoints were overall survival (OS) and progression-free survival (PFS); secondary endpoints included NRM and GVHD incidence.

RESULTS

A total of 55 patients were included (25 LBCLs, 16 indolent BCLs, 14 MCLs), and 76% of LBCLs were of indolent origin (Richter transformation, transformed follicular lymphoma). After a median follow-up of 6.1, 5.8 and 2.4 years for LBCLs, indolent BCLs and MCLs, their 5-year PFS and OS were 57.2% (IC 95%: 34.2-74.7) and 62.8% (IC 95%: 37.9-80.0), 81.2% (IC 95%: 52.5-93.5) and 93.8% (IC 95%: 63.2-99.1), and 39.0% (IC 95%: 14.3-63.3) and 68.1% (IC 95%: 35.4-86.8), respectively. The 5-year NRM was 16.9% (IC 95%: 8.2-28.3) with a relapse incidence of 23.4%. Overall/grade 3-4 acute GVHD occurred in 43.6% and 18.1% of patients. At 3 years, overall/moderate or severe chronic GVHD incidence was 49% and 34.5%.

CONCLUSIONS

AlloHCT remains a potentially curative option and should be considered for fit patients with chemosensitive FL or LBCLs of indolent origin and a low comorbidity index.