Umbilical Cord Blood or HLA-Haploidentical Transplantation: Real-World Outcomes versus Randomized Trial Outcomes. Transplant Cell Ther 2022 Feb;28(2):109.e1-109.e8
Date
11/15/2021Pubmed ID
34775146Pubmed Central ID
PMC8882346DOI
10.1016/j.jtct.2021.11.002Scopus ID
2-s2.0-85121144074 (requires institutional sign-in at Scopus site) 12 CitationsAbstract
Randomized clinical trials offer the highest-quality data for modifying clinical practice. Results of a phase III randomized trial of nonmyeloablative transplantation for adults with high-risk hematologic malignancies with 2 umbilical cord blood (UCB) units (n = 183) or HLA-haploidentical relative bone marrow (Haplo-BM; n = 154) revealed a 2-year progression-free survival (PFS) of 41% after Haplo-BM transplantation and 35% after 2-unit UCB transplantation (P = .41), with overall survival (OS) of 57% and 46%, respectively (P = .04). We sought to examine the generalizability of BMT CTN 1101 to a contemporaneous cohort beyond the trial's prespecified 2-year outcomes. All transplantations were performed between June 2012 and June 2018 in the United States. We hypothesized that the results of a rigorous phase III randomized trial would be generalizable. Changes in graft selection for HLA-haploidentical relative transplantation during the trial period allowed comparison of outcomes after transplantation with Haplo-BM with those after haploidentical peripheral blood (Haplo-PB). The trial's broad eligibility criteria were applied to the data source of the Center for International Blood and Marrow Transplant Research to select nontrial subjects. Extended follow-up of trial subjects was obtained from this data source. Three separate analyses were performed: (1) trial subjects beyond the trial's 2-year endpoint; (2) comparison of trial subjects with a contemporaneous cohort of nontrial subjects (195 2-unit UCB, 358 Haplo-BM, and 403 Haplo-PB); and (3) comparison of nontrial subjects by donor and graft type. Multivariate analyses were performed using Cox proportional hazards models for comparison of outcomes by treatment groups. With longer follow-up of the trial cohorts, 5-year PFS (37% versus 29%; P = .08) and OS (42% versus 36%; P = .06) were not significantly different between the treatment groups. We then compared the trial results with outcomes of comparable real-world transplantations. Five-year OS did not differ between trial and nontrial 2-unit UCB transplantations (36% versus 41%; P = .48) or between trial and nontrial Haplo-BM transplantations (42% versus 47%; P = .80), confirming generalizability. The randomized trial did not accrue as planned and therefore lacked the statistical power to detect a 15% difference in PFS. With substantially larger numbers of nontrial Haplo-BM transplantations, 5-year survival was higher after nontrial Haplo-BM compared with trial 2-unit UCB (47% versus 36%; P = .012). Nontrial patients who underwent Haplo-PB transplantation had higher 5-year survival (54%) compared with trial Haplo-BM (hazard ratio [HR], 0.76; P = .044) and nontrial Haplo-BM (HR, 0.78; P = .026). Similarly, survival was better after Haplo-PB compared with trial UCB (HR, 0.57; P < .0001) and nontrial UCB (HR, 0.63; P = .0002). When considering alternative donor low-intensity conditioning regimen transplantation, a haploidentical relative is preferred, and PB is the preferred graft source.
Author List
O'Donnell PV, Brunstein CG, Fuchs EJ, Zhang MJ, Allbee-Johnson M, Antin JH, Leifer ES, Elmariah H, Grunwald MR, Hashmi H, Horowitz MM, Magenau JM, Majhail N, Milano F, Morris LE, Rezvani AR, McGuirk JP, Jones RJ, Eapen MAuthors
Mary Eapen MBBS, DCh, MRCPI, MS Professor in the Medicine department at Medical College of WisconsinMary M. Horowitz MD, MS Professor in the Medicine department at Medical College of Wisconsin
MESH terms used to index this publication - Major topics in bold
AdultFetal Blood
Graft vs Host Disease
Humans
Transplantation Conditioning
Transplantation, Haploidentical
Unrelated Donors