Evidence into practice: Changes in haploidentical versus double umbilical cord blood graft utilization for hematopoietic cell transplantation in the U.S. in relation to a pivotal randomized clinical trial.

Abstract

e23306 Background: Randomized clinical trials are the “gold standard”, but expensive and not always practice changing. Umbilical cord blood (UCB) and haploidentical (haplo) are donor sources for hematopoietic cell transplant (HCT) patients who do not have a fully matched donor. The Blood and Marrow Transplant Clinical Trials Network (CTN) 1101 trial (2012-2018) compared outcomes of double UCB and haplo bone marrow (BM) transplantation. The trial showed a lower two-year overall survival after UCB compared to haplo (46% vs 57%, p = 0.04). Here, we quantified the change in graft selection in clinical practice in the U.S. after publication of the trial’s primary results. Methods: 11,190 U.S. HCT recipients 18-70 years of age who received either UCB (single or double units) or haplo transplants (BM or peripheral blood stem cells), for leukemias, lymphomas, myelodysplastic syndrome, myeloproliferative neoplasms, who reported to the Center for International Blood and Marrow Transplant Research database, were analyzed. Graft utilization was analyzed in 3 time periods: 2010-2012 (pre-study), 2013-2018 (during study), and 2019-2022 (post-study), using Chi-square test and multivariable logistic regression. Results: Over the 3 time periods, there was a practice change with an increasing proportion of haplo transplants vs UCB (32%, 68% and 91% of transplants, p < 0.001; odds ratio (OR) of 4.67 and 21.38 for during-study and post-study periods, respectively, both with p < 0.001, compared to pre-study period). Males and older patients were more likely to receive haplo (OR = 1.32, p < 0.001, and OR = 1.74, p < 0.001, respectively). Compared to White recipients, Black recipients were more likely to receive haplo (OR = 1.74, p < 0.001), whereas Asian recipients were less likely to receive haplo (OR = 0.75, p = 0.002). Hispanic recipients had a similar likelihood of receiving haplo to White patients (OR = 1.03, p = 0.665). Conclusions: Practice change toward haploidentical graft utilization had begun before the CTN 1101 trial’s publication and continued to increase over time. Black patients were more likely than White patients to receive haplo, and Asian patients were more likely than White patients to receive UCB. Availability of both UCB and haplo as alternative graft sources allowed for HCT for a diverse population. [Table: see text]