The expansion of hematopoietic cell transplantation in patients aged >75 years: A CIBMTR analysis, 2019–2023.

e13769 Background: Hematopoietic cell transplantation (HCT) is increasingly utilized in older adults; however, patients aged > 75 years have historically been excluded due to concerns regarding frailty and treatment-related toxicity. Advances in supportive care and reduced-intensity conditioning (RIC) have challenged these paradigms, prompting evaluation of real-world HCT utilization in the super-elderly population. Methods: We analyzed aggregate Center for International Blood and Marrow Transplant Research (CIBMTR) data for U.S. HCT recipients aged > 75 years between 2019 and 2023. Transplant activity was summarized by donor type, cell source, disease indication, and state. Temporal trends were assessed descriptively and modeled using Poisson regression, with results reported as incidence rate ratios (IRRs) and 95% confidence intervals. State-level transplant volumes were aggregated to assess geographic distribution. Results: Between 2019 and 2023, 1,670 HCTs were performed in patients aged > 75 years. Peripheral blood stem cells (PBSC) constituted the dominant graft source for both autologous and allogeneic transplantation throughout the study period, with minimal and stable use of bone marrow and cord blood. HCT utilization increased significantly over time(IRR 1.32 per year; p 75 years is accelerating, particularly within plasma cell disorders and myeloid malignancies, challenging historical age cutoffs. This expansion, facilitated by adoption of RIC and PBSC-based platforms, reflects a safety-conscious evolution in expanding access to older candidates. However, persistent geographic disparities necessitate broader access, particularly in states with aging populations. Integrating aging domains (frailty, cognition) into registries is critical to distinguish candidates benefiting from HCT versus those at risk for functional decline. Poisson regression analysis of HCT utilization in adults aged >75 years (2019–2023). Category Poisson IRR (95% CI) p Value Overall (per year) 1.32 (1.27–1.37) <0.001 Autologous vs allogeneic 1.15 (1.04–1.26) 0.005 Plasma cell disorders 71.2 <0.001 AML 18.2 <0.001 MDS 16.5 <0.001 NHL 16.0 <0.001 Acute leukemia, other, served as the reference category for disease-specific analyses. IRRs represent relative utilization compared with the reference group.