Real-world graft utilization after CTN-1101: a registry-based analysis of haploidentical graft versus umbilical cord blood trends

Randomized clinical trials are expensive and not always practice changing. The Blood and Marrow Transplant Clinical Trials Network (CTN) 1101 trial (2012-2018) showed a lower two-year overall survival after umbilical cord blood (UCB) compared to haploidentical graft (haplo) transplants. To quantify the change in graft utilization after the trial's publication, a cohort of 11,190 U.S. adult HCT recipients selected with inclusion/exclusion criteria similar to CTN-1101's were analyzed across three time periods: 2010-2012 (pre-study), 2013-2018 (during-study), and 2019-2022 (post-study). We found a significant increase in haplo utilization compared to UCB, with the trend beginning around 2013. Compared to non-Hispanic White, Black recipients were more likely to receive haplo, Asian recipients were less likely, and Hispanic recipients had similar rates. We also expanded our analyses to 61,465 patients to assess haplo and UCB utilization compared to other allogeneic donors. In this cohort, utilization of alternative donor grafts increased when compared to HLA-matched related or unrelated donor grafts for Black, Hispanic, and Asian recipients. Our findings demonstrate practice change toward haplo transplants had begun before the CTN-1101 trial's publication and continued to significantly increase afterward. HLA-mismatched donors are vital alternative graft sources, allowing patients of all backgrounds to receive HCT.