Representativeness of Blood and Marrow Transplant Clinical Trials Network (BMT CTN) Trial Participants

Underrepresentation by race and ethnicity in oncology clinical trials, including those of hematopoietic cell transplantation (HCT), is a known challenge. This analysis studied accrual on Blood and Marrow Transplant Clinical Trials Network (BMT CTN) trials conducted in 2014 to 2020 by race/ethnicity, age, and sex, comparing these characteristics with those of potentially eligible patients identified from the Surveillance, Epidemiology, and End Results (SEER) and Center for International Blood and Marrow Transplant Research (CIBMTR) databases for the disease, age, and years of interest of BMT CTN studies. Five BMT CTN trials met the inclusion criteria, including 1 autologous HCT trial and 4 allogeneic HCT trials. Two studies focused on multiple myeloma (BMT CTN 1302 and 1401), 2 studies focused on graft-versus-host disease (GVHD) treatment (BMT CTN 1301 and 1501), and 1 study focused on post-HCT maintenance therapy in FLT3⁺ acute myelogenous leukemia (BMT CTN 1506). A decline in the proportion of patients from minority racial and ethnic groups was seen from the SEER population to trial enrollees, with the largest drop seen between the SEER population and all patients who underwent HCT (on or off trial) at US transplant centers. Allogeneic HCT trials that allowed alternative donor graft sources had less decrease from the SEER population. No decrease in clinical trial enrollment was seen with respect to older age and female HCT recipients. This study provides insight into the underrepresentation of racial and ethnic minority patients in BMT CTN clinical trials, owing largely to lack of access to HCT in general. Pathways expanding access to donors and improving the outreach of HCT programs to underserved populations are needed to improve access to clinical trials.