Hematopoietic stem cell transplantation for DLBCL: a report from the European Society for Blood and Marrow Transplantation on more than 40,000 patients over 32 years.

Autologous(auto-) and allogeneic(allo-) hematopoietic stem cell transplantation (HSCT) are key treatments for relapsed/refractory diffuse large B-cell lymphoma (DLBCL), although their roles are challenged by CAR-T-cells and other immunotherapies. We examined the transplantation trends and outcomes for DLBCL patients undergoing auto-/allo-HSCT between 1990 and 2021 reported to EBMT. Over this period, 41,148 patients underwent auto-HSCT, peaking at 1911 cases in 2016, while allo-HSCT saw a maximum of 294 cases in 2018. The recent decline in transplants corresponds to increased CAR-T treatments (1117 cases in 2021). Median age for auto-HSCT rose from 42 (1990-1994) to 58 years (2015-2021), with peripheral blood becoming the primary stem cell source post-1994. Allo-HSCT median age increased from 36 (1990-1994) to 54 (2015-2021) years, with mobilized blood as the primary source post-1998 and reduced intensity conditioning post-2000. Unrelated and mismatched allo-HSCT accounted for 50% and 19% of allo-HSCT in 2015-2021. Three-year overall survival (OS) after auto-HSCT improved from 56% (1990-1994) to 70% (2015-2021), p < 0.001, with a decrease in relapse incidence (RI) from 49% to 38%, while non-relapse mortality (NRM) remained unchanged (4%). After allo-HSCT, 3-year-OS increased from 33% (1990-1999) to 46% (2015-2021) (p < 0.001); 3-year RI remained at 39% and 1-year-NRM decreased to 19% (p < 0.001). Our data reflect advancements over 32 years and >40,000 transplants, providing insights for evaluating emerging DLBCL therapies.

Older MRD vs. younger MUD in patients older than 50 years with AML in remission using post-transplant cyclophosphamide.

An increasing number of older patients with acute myeloid leukemia (AML) are offered an allogeneic hematopoietic stem cell transplantation (allo-HSCT). Normally, older patients have older matched related donors (MRD). Matched unrelated donors (MUD) are an important alternative, but it remains unclear whether a younger MUD is associated with better outcomes, especially in the context of post-transplant cyclophosphamide (PTCy). We compared outcomes of patients older than 50 years with AML in first complete remission (CR1) and receiving a first HSCT from a 10/10 MUD aged younger than 40 years to those receiving a graft from a MRD aged older than 50 years, using PTCy and with well-known transplant conditioning intensity (TCI) score. A total of 345 consecutive patients were included and classified according to TCI score as low, intermediate, or high. On multivariable analysis in the TCI-intermediate/high group, MUD was associated with better graft-versus-host disease-free, relapse-free survival, lower non-relapse mortality and lower relapse incidence. For patients receiving a TCI-low regimen, outcomes are independent on the type of donor. In patients with AML in CR1, older than 50 years and receiving a TCI-intermediate/high conditioning regimen using PTCy, a MUD younger than 40 years is preferable over a MRD older than 50 years.

Younger unrelated donors may be preferable over HLA match in the PTCy era: a study from the ALWP of the EBMT.

ABSTRACT: There is a paucity of information on how to select the most appropriate unrelated donor (UD) in hematopoietic stem cell transplantation (HSCT) using posttransplant cyclophosphamide (PTCy). We retrospectively analyzed the characteristics of 10/10 matched UDs (MUDs) and 9/10 mismatched UDs (MMUDs) that may affect transplant outcomes in patients with acute myeloid leukemia (AML) in first or second complete remission (CR1 or CR2). The primary end point was leukemia-free survival (LFS). Overall, 1011 patients were included with a median age of 54 years (range, 18-77). Donors had a median age of 29 years (range, 18-64); 304 (30%) were females, of which 150 (15% of the whole group) were donors to male recipients, and 621 (61%) were MUDs; 522 (52%) had negative cytomegalovirus (CMV-neg) serostatus, of which 189 (19%) were used for CMV-neg recipients. Donor age older than 30 years had a negative impact on relapse (hazard ratio [HR], 1.38; 95% confidence interval [CI], 1.06-1.8), LFS (HR, 1.4; 95% CI, 1.12-1.74), overall survival (HR 1.45; 95% CI, 1.14-1.85) and graft-versus-host disease (GVHD) free, relapse-free survival (HR, 1.29; 95% CI, 1.07-1.56). In addition, CMV-neg donors for CMV-neg recipients were associated with improved LFS (HR, 0.74; 95% CI, 0.55-0.99). The use of MMUD and female donors for male recipients did not significantly impact any transplant outcomes. For patients undergoing HSCT from a UD with PTCy for AML, donor age <30 years significantly improves survival. In this context, donor age might be prioritized over HLA match considerations. In addition, CMV-neg donors are preferable for CMV-neg recipients. However, further research is needed to validate and refine these recommendations.