Allogeneic Hematopoietic Stem Cell Transplantation in R/R B-Cell Non-Hodgkin Lymphoma

Refractory/relapsed B-cell non-Hodgkin lymphoma (R/R B-NHL) presents significant treatment challenges, according to researchers at the 2024 ASH Annual Meeting. While CAR-T cell therapy has emerged as a transformative salvage option for around 40% of patients, long-term data on allogeneic hematopoietic stem cell transplantation (allo-HSCT) remain sparse. Future studies should explore combining allo-HSCT with novel therapies to enhance outcomes further, the researchers noted.. A multicenter study evaluated outcomes for 281 patients with R/R B-NHL who underwent allo-HSCT between 2000 and 2020.

Patients (median age 50 years) included those with indolent lymphomas (43.3%), aggressive B-cell lymphomas (43.7%), and mantle cell lymphoma (MCL, 13%). At transplant, 47.7% were in complete remission (CR). The study’s median follow-up was 16 months for progression-free survival (PFS) and 24 months for overall survival (OS).

Five-year PFS and OS rates were 41.2% and 48.8%, respectively. Positive predictors for PFS included indolent histology and achieving CR at transplant. Indolent lymphomas demonstrated superior outcomes, with a 3-year PFS of 55.6%, compared to 37.9% for aggressive lymphomas and 27.0% for MCL. Patients in CR had markedly better outcomes (3-year PFS, 52.7%) than those with stable or progressive disease. Notably, MCL patients not in CR exhibited the poorest prognosis, with 0% PFS at 2 years.

Disease-related mortality was 19.2% at 5 years, while non-relapse mortality reached 31.9%, including early toxic events (26.1% at 12 months). Grade 3–4 acute graft-versus-host disease (GVHD) occurred in 9.1%, and chronic GVHD requiring therapy affected 13.5% at 3 years.

Overall, 35% of patients became long-term survivors, with 80 achieving continuous CR. These findings underscore that allo-HSCT remains a viable curative option for high-risk R/R B-NHL, particularly for patients in CR or those with indolent disease.

Future studies should explore combining allo-HSCT with novel therapies to enhance outcomes further, the researchers noted.

Reference:

Tarella C, Sammassimo S, Frassoni S, et al. Allogeneic hematopoietic stem cell transplantation for relapsed or refractory b-cell non-Hodgkin lymphoma: A retrospective multicenter analysis on 285 procedures performed between 2000 and 2020. Abstract 194320. Presented at ASH 2024. San Diego, California.