Decreased Mortality in 1-Year Survivors of Umbilical Cord Blood Transplant vs. Matched Related or Matched Unrelated Donor Transplant in Patients with Hematologic Malignancies.

Allogeneic hematopoietic stem cell transplantation (HCT) has the potential to cure hematologic malignancies but is associated with significant morbidity and mortality. Although deaths during the first year after transplantation are often attributable to treatment toxicities and complications, death after the first year may be due to sequelae of accelerated aging caused by cellular senescence. Cytotoxic therapies and radiation used in cancer treatments and conditioning regimens for HCT can induce aging at the molecular level; HCT patients experience time-dependent effects, such as frailty and aging-associated diseases, more rapidly than people who have not been exposed to these treatments. Consistent with this, recipients of younger cells tend to have decreased markers of aging and improved survival, decreased graft-versus-host disease, and lower relapse rates. Given that umbilical cord blood (UCB) is the youngest donor source available, we studied the outcomes after the first year of UCB transplantation versus matched related donor (MRD) and matched unrelated donor (MUD) transplantation in patients with hematologic malignancies over a 20-year period. In this single-center, retrospective study, we examined the outcomes of all adult patients who underwent their first allogeneic HCT through the Duke Adult Bone Marrow Transplant program from January 1, 1996, to December 31, 2015, to allow for at least 3 years of follow-up. Patients were excluded if they died or were lost to follow-up before day 365 after HCT, received an allogeneic HCT for a disease other than a hematologic malignancy, or received cells from a haploidentical or mismatched adult donor. UCB recipients experienced a better unadjusted overall survival than MRD/MUD recipients (log rank P = .03, median overall survival: UCB not reached, MRD/MUD 7.4 years). After adjusting for selected covariates, UCB recipients who survived at least 1 year after HCT had a hazard of death that was 31% lower than that of MRD/MUD recipients (hazard ratio, 0.69; 95% confidence interval, 0.47-0.99; P = .049). This trend held true in a subset analysis of subjects with acute leukemia. UCB recipients also experienced lower rates of moderate or severe chronic graft-versus-host disease (GVHD) and nonrelapse mortality, and slower time to relapse. UCB and MRD/MUD recipients experienced similar rates of grade 2-4 acute GVHD, chronic GHVD, secondary malignancy, and subsequent allogeneic HCT. UCB is already widely used as a donor source in pediatric HCT; however, adult outcomes and adoption have historically lagged behind in comparison. Recent advancements in UCB transplantation such as the implementation of lower-intensity conditioning regimens, double unit transplants, and ex vivo expansion have improved early mortality, making UCB an increasingly attractive donor source for adults; furthermore, our findings suggest that UCB may actually be a preferred donor source for mitigating late effects of HCT.

Bohannon L ，Tang H ，Page K ，Ren Y ，Jung SH ，Artica A ，Britt A ，Islam P ，Siamakpour-Reihani S ，Giri V ，Lew M ，Kelly M ，Choi T ，Gasparetto C ，Long G ，Lopez R ，Rizzieri D ，Sarantopoulos S ，Chao N ，Horwitz M ，Sung A ... -  《-》

Reduced-intensity allogeneic transplant in patients older than 55 years: unrelated umbilical cord blood is safe and effective for patients without a matched related donor.

Majhail NS ，Brunstein CG ，Tomblyn M ，Thomas AJ ，Miller JS ，Arora M ，Kaufman DS ，Burns LJ ，Slungaard A ，McGlave PB ，Wagner JE ，Weisdorf DJ ... -  《-》

Low-Dose Antithymocyte Globulin for Graft-versus-Host-Disease Prophylaxis in Matched Unrelated Allogeneic Hematopoietic Stem Cell Transplantation.

Graft-versus-host disease (GVHD) is a leading cause of morbidity and mortality in allogeneic hematopoietic stem cell transplantation (alloHCT). Prophylactic in vivo T cell depletion with antithymocyte globulin (ATG) has been associated with decreased GVHD rates in many alloHCT settings. Despite decades of clinical study, optimal ATG dosing has not been established. Understanding that higher rates of GVHD are observed with matched unrelated donor (MUD) versus matched related donor (MRD) alloHCT, at our institution MUD alloHCT recipients have historically had low-dose Thymoglobulin (total dose, 2.5 mg/kg; Genzyme-Sanofi, Cambridge, MA) added to our standard MRD GVHD prophylaxis regimen. In this retrospective cohort study we assessed post-HCT the effectiveness of our uniquely low-dose ATG strategy by comparing ATG exposed (MUD) and unexposed (MRD) alloHCT recipients for GVHD and other clinical HCT outcomes. This retrospective single-center study included all HCT patients transplanted for any malignant indication at The Ottawa Hospital from 2009 to 2014. MUD patients received rabbit ATG (Thymoglobulin) at a total dose of 2.5 mg/kg given over 2 days (.5 mg/kg on day -2; 2.0 mg/kg on day -1 before stem cell infusion) in addition to standard GVHD prophylaxis. Primary outcomes assessed were incidence of acute and chronic GVHD, defined as new-onset GVHD requiring systemic immunosuppressive therapy at less or more than 100 days, respectively. Secondary outcomes included disease relapse and survival. There were 110 and 77 patients in the ATG exposed (MUD) and unexposed (MRD) cohorts, respectively. At baseline there were no significant differences in median age at transplant, sex, disease indication or risk index, graft source, conditioning regimen, or intensity between cohorts. A higher proportion of 7/8 mismatched donor transplants (13% versus 3%, P = .02) and a higher median CD34+ dose (7.9 versus 4.9 × 108 cells; P < .01) was observed in the ATG exposed cohort. No differences were noted in platelet engraftment. ATG exposed patients had significantly shorter time to neutrophil engraftment than the unexposed cohort (16 versus 19 days, respectively; P < .01). ATG exposed patients had significantly lower rates of GVHD than ATG unexposed patients (57% versus 79%; P = .01), with differences predominantly in rates of chronic GVHD (18% versus 44%, P < .01). At median follow-up of 28 (range, 3 to 69) and 25 (range, 2 to 73) months for survivors in ATG exposed and unexposed cohorts, respectively, no significant differences in overall survival (median overall survival not met for either cohort), relapse incidence (26% versus 29%, P = .73), or relapse-free survival (RFS) (not met in ATG exposed and 26 months in ATG unexposed, P = .22) were observed between groups. The ATG exposed cohort had significantly higher GVHD-free RFS (GRFS) with a 2-year GRFS of 23% versus 3% (P = .003). There were no significant differences between cohorts in proportion of patientswith post-HCT infectious episodes or intensive care unit admissions. Here we report significantly lower rates of chronic GVHD and significant improvement in GRFS in an ATG exposed MUD alloHCT cohort compared with an ATG unexposed MRD cohort. These findings were observed without differences in relapse, survival, infectious complications, or intensive care unit admissions. Our findings highlight the association of unconventionally low-dose ATG with improved GVHD outcomes and suggest a need for prospective study of ATG use in lower doses.

Bryant A ，Mallick R ，Huebsch L ，Allan D ，Atkins H ，Anstee G ，Sabloff M ，Scrivens N ，Maze D ，Bredeson C ，Kekre N ... -  《-》

Poor outcome with nonmyeloablative conditioning regimen before cord blood transplantation for patients with high-risk acute myeloid leukemia compared with matched related or unrelated donor transplantation.

Allogeneic hematopoietic stem cell transplantation (Allo-HSCT) is recommended for patients with high-risk acute myeloid leukemia (AML). In many situations, a matched related (MRD) or matched unrelated donor (MUD) is lacking, in which case unrelated cord blood units (UCB) provide an alternative. We analyzed the outcome of consecutive high-risk AML patients prepared with reduced-intensity conditioning (RIC) regimens and allografted with UCB (n = 32) and compared their outcome with high-risk AML patients who underwent transplantation with MRD/MUD (n = 49) in the same period of time. Grade III to IV acute graft-versus-host disease (GVHD) occurred slightly more frequently in the UCB group (25%) than in the MRD/MUD group (8%) (P = .069). Conversely, we found a lower incidence of extensive chronic GVHD in the UCB group (6%) than in the MRD/MUD group (20%, P = .085). Nonrelapse mortality at 4 years was 16% and 22% in the UCB and MRD/MUD groups, respectively (P = .529). The cumulative incidence of relapse at 4 years was significantly higher in the UCB group (60%) than in the MRD/MUD group (27%, P = .006). Leukemia-free survival (LFS) and overall survival (OS) at 4 years were 25% and 34%, respectively, in the UCB group and 50% and 56%, respectively, in the MRD/MUD group (LFS, P = .029; OS, P = .072). Multivariate analyses adjusted by cytogenetics and disease status at the time of Allo-HSCT revealed that use of UCB remained an independent predictive factor of shorter LFS (hazard ratio, 2.0; 95% confidence interval, 1.1 to 3.6; P = .018), and was associated with a trend for shorter OS (hazard ratio, 1.7; 95% confidence interval, .9 to 3.2; P = .093). Whereas UCB provides an alternative for patients with high-risk AML lacking an MRD/MUD, the high incidence of relapse after RIC-based UCB Allo-HSCT is a concern. Attempts to improve leukemic control with UCB Allo-HSCT are warranted, as well as the evaluation of other alternative donors in this context.

Devillier R ，Harbi S ，Fürst S ，Crocchiolo R ，El-Cheikh J ，Castagna L ，Etienne A ，Calmels B ，Lemarie C ，Prebet T ，Granata A ，Charbonnier A ，Rey J ，Chabannon C ，Faucher C ，Vey N ，Blaise D ... -  《-》

Effect of graft source on unrelated donor hemopoietic stem cell transplantation in adults with acute myeloid leukemia after reduced-intensity or nonmyeloablative conditioning: a study from the Société Francaise de Greffe de Moelle et de Thérapie Cellulair

This retrospective report compared the 4-year outcomes of allogeneic stem cell transplantation (allo-SCT) in 651 adult patients with acute myeloid leukemia receiving a reduced-intensity (RIC) or nonmyeloablative conditioning (NMA) regimen according to the type of unrelated donors. These were either umbilical cord blood (UCB, n = 205), a 9/10 mismatched unrelated donor (MisMUD, n = 99), or a 10/10 matched unrelated donor (MUD, n = 347) graft. Neutrophil recovery was slower in UCB (74.5% by day 42) compared with MisMUD (94.8%) and MUD (95.6%) (P < .001). There was no significant difference in nonrelapse mortality between UCB and both MUD (hazard ratio [HR], 1.05; 95% confidence interval [CI], .62 to 1.78; P = .85) and MisMUD (HR, 1.58; 95% CI, .88 to 2.83; P = .13) The relapse/progression was similar between UCB and MisMUD (HR, .62; 95% CI, .37 to 1.03; P = .07), but was significantly lower in MUD compared with UCB (HR, .60; 95% CI, .39 to .92; P = .02). The rate of extensive chronic graft-versus-host disease (GVHD) was similar between UCB and both MUD (HR, 2.15; 95% CI, .93 to 4.97; P = .08) and MisMUD (HR, 1.84; 95% CI, .68 to 4.95; P = .23). The rate of severe grade III and IV acute GVHD was significantly increased in MisMUD compared with UCB (HR, 2.61; 95% CI, 1.30 to 5.23; P = .007). There was no significant difference in overall survival between UCB and both MisMUD (HR, .98; 95% CI, .66 to 1.45; P = .92) and MUD (HR, .74; 95% CI, .52 to 1.03; P = .08). These data suggest that in the setting of RIC/NMA, allo-SCT UCB is a valid alternative graft source, with significantly less chronic GVHD, compared with MisMUD, when there is no MUD available or when urgent transplantation is needed.

Malard F ，Milpied N ，Blaise D ，Chevallier P ，Michallet M ，Lioure B ，Clément L ，Hicheri Y ，Cordonnier C ，Huynh A ，Yakoub-Agha I ，Peffault de Latour R ，Mohty M ... -  《-》