Impact of graft-versus-host disease on outcomes after unrelated cord blood transplantation

Allogeneic hematopoietic cell transplantation from alternative donors in acute myeloid leukemia

Allogeneic hematopoietic cell transplantation (HCT) potentially provides a cure for patients with acute myeloid leukemia (AML) who are unlikely to be cured with chemotherapy alone. Previously, human leukocyte antigen (HLA)-matched related donors were used exclusively, which made the procedure available for a limited proportion of patients. The introduction of high-resolution HLA-typing technology, innovations in immunosuppressive therapy, and improved supportive care measures have significantly changed the situation. Now, patients without a matched related donor have an ample opportunity to receive allogeneic HCT with the use of matched or mismatched unrelated donors, umbilical cord blood grafts, or haploidentical related donors. The outcomes of alternative donor transplantations have improved over the past decades, and the growth of unrelated donor registries as well as the donor diversification have enhanced the chance of finding a suitable donor. With multiple alternative donor choices available for most patients, the donor selection is becoming increasingly important. To discuss the optimal donor choice in case of unavailability of an HLA-matched related donor, this article reviews the existing literature of retrospective and prospective comparisons of different alternative donor transplantations in AML and discusses the current state-of-art modalities in allogeneic HCT using alternative donors.

Allogeneic transplantation of bone marrow versus peripheral blood stem cells from HLA-identical sibling donors for hematological malignancies in 6064 adults from 2003 to 2020: different impacts on survival according to time period

BACKGROUND

Mobilized peripheral blood stem cells (PBSC) have been widely used instead of bone marrow (BM) as the graft source for allogeneic hematopoietic cell transplantation (HCT). Although early studies demonstrated no significant differences in survival between PBSC transplantation (PBSCT) and BM transplantation (BMT) from human leukocyte antigen (HLA)-identical sibling donors to adults with hematological malignancies, recent results have been unclear.

OBJECTIVE

The objective of this retrospective study was to compare overall survival (OS), relapse, non-relapse mortality (NRM), hematopoietic recovery and graft-versus-host disease (GVHD) between PBSCT and BMT according to the time period of HCT (2003-2008, 2009-2014, or 2015-2020).

STUDY DESIGN

We retrospectively compared the outcomes after PBSCT versus BMT in 6064 adults with hematological malignancies using a Japanese registry database between 2003 and 2020.

RESULTS

The adjusted probability of OS was significantly higher in BMT recipients compared to PBSCT recipients during the early period of 2003-2008 (adjusted hazard ratio [HR], 0.79; 95% confidence interval [CI], 0.70-0.91; P < 0.001) and the middle period of 2009-2014 (adjusted HR, 0.80; 95% CI, 0.70-0.91; P < 0.001). However, during the late period of 2015-2020, the adjusted probability of OS was comparable between BMT and PBSCT recipients (adjusted HR, 0.94; 95% CI, 0.79-1.13; P = 0.564), which were mainly due to the reduction of NRM. There was no significant difference in the relapse rate between the groups, irrespective of the time period. Compared to BMT, PBSCT led to faster neutrophil and platelet recovery and the cumulative incidences of grades II-IV and grades III-IV acute and overall and extensive chronic GVHD were significantly higher in PBSCT recipients, irrespective of the time period.

CONCLUSIONS

PBSCT and BMT had similar survival outcomes and relapse rates in adult patients with hematological malignancies during the late time period of 2015-2020 despite the hematopoietic recovery and acute and chronic GVHD being higher in PBSCT recipients in all time periods.

Effect of Conditioning Regimens and Graft-versus-Host Disease Prophylaxis on the Outcomes of Umbilical Cord Blood Transplantation Performed with Cyclophosphamide/Total Body Irradiation-Based Regimens

Umbilical cord blood (UCB) is a valuable alternative donor source for allogeneic hematopoietic stem cell transplantation. Various conditioning regimens and graft-versus-host disease (GVHD) prophylaxis regimens aimed at improving the outcomes of umbilical cord blood transplantation (UCBT) have been explored; however, the differences in their effects remain unclear. This study was conducted to elucidate the differences in the effects of conditioning and GVHD prophylaxis regimens on UCBT outcomes by disease type in a nationwide, retrospective study. We retrospectively analyzed the effects of conditioning and GVHD prophylaxis regimens on the outcomes of UCBT performed with cyclophosphamide (Cy)/total body irradiation (TBI)-based regimens in patients with acute myeloid leukemia (AML; n = 1126), acute lymphoblastic leukemia (ALL; n = 620), myelodysplastic syndrome (MDS; n = 170), and lymphoma (n = 128). Multivariate analysis for overall survival (OS) demonstrated the benefit of adding high-dose cytarabine to the Cy/TBI regimen for the AML group (relative risk [RR], .76; P = .003) and lymphoma group (RR, .54; P = .02), but not for the ALL and MDS groups. In the ALL group, adding etoposide to the Cy/TBI regimen was associated with a lower OS (RR, 1.45; P = .03). For GVHD prophylaxis, a tacrolimus/methotrexate regimen was associated with a lower OS compared with a cyclosporine/methotrexate regimen in the AML group (RR, 1.26; P = .01); this difference was not observed in the other groups. These differences in OS according to the conditioning and GVHD prophylaxis regimen were attributable mainly to differences in relapse risk. Our data show that the effects of conditioning regimens and GVHD prophylaxis on UCBT outcomes differed according to disease type. UCBT outcomes could be improved by selecting optimal conditioning regimens and GVHD prophylaxis for each disease type.

The impact of malnutrition on mortality and complications of hematopoietic stem cell transplantation in patients with acute leukemia

BACKGROUND & AIMS

Malnutrition is common in hematopoietic stem cell transplantation (HSCT) patients. However, there are few studies on the association between malnutrition and post-transplant outcomes, with inconsistent results. No standard screening tool has been established for malnutrition in these patients. Previous research suggests the Global Leadership Initiative on Malnutrition (GLIM) criteria is effective in predicting outcomes in other cancers. This study investigates the link between malnutrition based on the GLIM criteria with mortality and complications following allogeneic HSCT.

METHODS

This single-center, observational, longitudinal, and prospective study of 98 adult leukemia patients at the Hematology Center of Shariati Hospital in Tehran, Iran, monitored patients before transplantation until 100 days after the procedure, focusing on overall survival and mortality as a primary outcome, and secondary endpoints including oral mucositis, acute GVHD, infection during hospitalization, and readmission rates.

RESULTS

This study involved 98 allogeneic HSCT patients with a median age of 38 years old, 64.3 % with acute myeloid leukemia (AML), and 35.7 % with acute lymphoblastic leukemia (ALL). Among them, 26.5 % were categorized as malnourished based on GLIM criteria. During 100 days of follow-up, 13 patients died, but there was no significant difference in overall survival and mortality between malnourished and well-nourished patients. Malnourished patients demonstrated a noticeable upward trend in the incidence of oral mucositis, hospital readmission, and infection during their hospitalization. It is important to highlight that although this observed trend is discernible, it did not attain statistical significance in statistical analyses (P > 0.05).

CONCLUSION

The current study determined that, when assessed using the GLIM criteria, malnutrition did not exert a statistically significant influence on survival, mortality, or complications within the specified age range of 18-55 years, underscoring its limited impact on this cohort of younger patients.

Hematopoiesis in the spleen after engraftment in unrelated cord blood transplantation evaluated by 18F-FLT PET imaging

Cord blood is an important donor source for allogeneic hematopoietic stem cell transplantation (allo-HSCT), with its unique composition and quality of hematopoietic cells. The proliferation site and potency of infused hematopoietic stem cells in humans may vary between stem cell sources. We investigated this possibility in a prospective, exploratory study to assess hematopoietic dynamics using the radiopharmaceutical 3'-deoxy-3'-18F-fluorothymidine (18F-FLT), a thymidine analog used in positron emission tomography imaging, before allo-HSCT and on days 50 and 180 after allo-HSCT. We evaluated 11 patients with hematological malignancies who underwent allo-HSCT [five with peripheral blood stem cell transplantation (PBSCT) and six with unrelated cord blood transplantation (UCBT)]. Before allo-HSCT, 18F-FLT uptake did not differ between the two groups. At day 50, 18F-FLT uptake in the spleen was significantly greater in the UCBT group than in the PBSCT group (p = 0.0043), with no difference in whole-body bone marrow. At day 180, the differences in spleen uptake had diminished, and there were no differences between groups in whole-body bone marrow or the spleen, except for the sternum. The persistence of splenic hematopoiesis after engraftment in the UCBT group may reflect the complex systemic homing and proliferation mechanisms of cord blood hematopoietic cells.

Effect of graft-versus-host disease on posttransplant outcomes following single cord blood transplantation in comparison to haploidentical transplantation with posttransplant cyclophosphamide for adult acute myeloid leukemia

BACKGROUND

The possibility that human leukocyte antigen (HLA) mismatches could reduce relapse after alternative HLA-mismatched allogeneic hematopoietic cell transplantation (HCT) is an attractive concept for acute myeloid leukemia (AML). However, it remains unclear whether the prognostic effect of graft-versus-host disease (GVHD) on survival differs between single-unit cord blood transplantation (CBT) or haploidentical HCT using posttransplant cyclophosphamide (PTCy-haplo HCT) for AML.

OBJECTIVE

The objective of this retrospective study was to compare the effect of acute and chronic GVHD on posttransplant outcomes between CBT and PTCy-haplo HCT.

STUDY DESIGN

We retrospectively evaluated the effect of acute and chronic GVHD on posttransplant outcomes following CBT and PTCy-haplo HCT in adults with AML (n=1,981) between 2014 and 2020 using a Japanese registry database.

RESULTS

In the univariate analysis, the probability of overall survival was significantly greater in patients who developed grade I-II acute GVHD (P<0.001 by log-rank test) and limited chronic GVHD (P<0.001 by log-rank test) among CBT recipients, but these effects were not significant among PTCy-haplo HCT recipients. In the multivariate analysis, in which the development of GVHD was treated as a time-dependent covariate, the effect of grade I-II acute GVHD on reducing overall mortality was significant between CBT and PTCy-haplo HCT (adjusted hazard ratio [HR] for CBT: 0.73, 95% confidence interval [CI]: 0.60-0.87; adjusted HR for PTCy-haplo HCT: 1.07, 95% CI: 0.70-1.64; p for interaction=0.038).

CONCLUSION

Our data demonstrate that grade I-II acute GVHD was associated with a significant improvement in overall mortality in adults with AML receiving CBT but not PTCy-haplo HCT.

Advantages of Higher Busulfan Dose Intensity in Fludarabine-Combined Conditioning for Patients with Acute Myeloid Leukemia Undergoing Cord Blood Transplantation

The alkylating agent busulfan is commonly used as conditioning in allogeneic hematopoietic stem cell transplantation for acute myeloid leukemia (AML). However, a consensus has not yet been reached regarding the optimal busulfan dose in cord blood transplantation (CBT). Therefore, we conducted this large nationwide cohort study to retrospectively analyze the outcomes of CBT in patients with AML receiving busulfan at intermediate (6.4 mg/kg i.v.; BU2) or higher (12.8 mg/kg i.v.; BU4) doses within a fludarabine/i.v. busulfan (FLU/BU) regimen. Among 475 patients who underwent their first CBT following FLU/BU conditioning between 2007 and 2018, 162 received BU2 and 313 received BU4. Multivariate analysis identified BU4 as a significant factor for longer disease-free survival (hazard ratio [HR], .85; 95% confidence interval [CI], .75 to .97; P = .014) and a lower relapse rate (HR, .84; 95% CI, .72 to .98; P = .030). No significant differences were observed in non-relapse mortality between BU4 and BU2 (HR, 1.05; 95% CI, .88-1.26; P = .57). Subgroup analyses showed that BU4 provided significant benefits for patients who underwent transplantation while not in complete remission (CR) and those age <60 years. Our present results suggest that higher busulfan doses are preferable in patients undergoing CBT, particularly those not in CR and younger patients.

Intensified conditioning regimens improved disease-free survival and engraftment after unrelated single-unit cord blood transplantation but not after matched sibling or matched unrelated donor allogeneic hematopoietic cell transplantation

The impact of conditioning intensity on different donor groups has been unclear in allogeneic transplantation. The objective of this study was to clarify the effect of conditioning intensity on disease-free survival (DFS), relapse, non-relapse mortality (NRM), neutrophil engraftment, and graft-versus-host disease for each donor type. We retrospectively evaluated the effect of conditioning intensity on transplant outcomes for patients with acute leukemia or myelodysplastic syndrome aged between 16 and 60 years in Japan using the transplant conditioning intensity (TCI) scoring system. A total of 8526 patients who received first allogeneic transplantation from 6/6 antigen-matched sibling donor (MSD, n = 2768), 8/8 allele-matched unrelated donor (MUD, n = 2357), and unrelated single-cord blood (UCB, n = 3401) were eligible for the analyses. Compared to conditioning with TCI score 4.0, which was corresponds to conventional myeloablative conditioning, including cyclophosphamide with total body irradiation 12 Gy or busulfan 12.8 mg, and was considered as the reference group in the multivariate analyses, intensified conditioning with TCI score ≥4.5 improved DFS (hazard ratio [HR],0.81, P < 0.001) and relapse rate (HR, 0.70, P < 0.001) but only after UCB transplants and not MSD and MUD transplants. In contrast, NRM was higher after intensified conditioning with TCI score ≥4.5 for MSD (HR, 1.39, P = 0.008) and MUD (HR, 1.47, P = 0.002) transplants but not UCB transplants (HR, 1.12, P = 0.240). Neutrophil engraftment was also significantly higher after intensified conditioning with TCI score ≥4.5 but only for UCB transplants (HR, 1.24, P < 0.001), whereas it was significantly lower after reduced-intensity conditioning with TCI score ≤3.5 for MSD transplants only (HR, 0.82, P < 0.001). These data demonstrated that an intensified conditioning regimen improved survival and engraftment rate only after a UCB transplants. Therefore, TCI scoring system could enable the optimization of conditioning intensity according to donor type, particularly in terms of survival and engraftment.

Mild Acute Graft-Versus-Host Disease Improves Outcomes After HLA-Haploidentical-Related Donor Transplantation Using Posttransplant Cyclophosphamide and Cord Blood Transplantation

Haploidentical-related donor transplantation using posttransplant cyclophosphamide (PTCy-haplo) and cord blood transplantation (CBT) are valid alternatives for patients with hematological malignancies when HLA-matched donor transplantation (MDT) is unavailable. However, the effects of graft-versus-host disease (GVHD) on outcomes after these transplants have not been fully elucidated. Therefore, we evaluated the effects of acute and chronic GVHD on transplant outcomes after PTCy-haplo transplants and compared them with CBT and MDT. We included a total of 914 adult patients with hematological malignancies in the Kyoto Stem Cell Transplantation Group registry who received PTCy-haplo (N = 120), CBT (N = 402), and MDT (N = 392), and achieved neutrophil engraftment. A multivariate analysis revealed that grade I-II acute GVHD improved of overall survival (OS) after PTCy-haplo [hazard ratio (HR) = 0.39, P = 0.018] and CBT (HR = 0.48, P < 0.001), but not after MDT (HR = 0.80, P = 0.267) compared with patients without acute GVHD. Grade I-II acute GVHD had a trend toward reducing the risk of nonrelapse mortality (NRM) after PTCy-haplo (HR = 0.13, P = 0.060) and this positive effect was significant after CBT (HR = 0.39, P = 0.003). A negative impact of grade III-IV acute GVHD on NRM was observed after CBT and MDT, but not after PTCy-haplo. Limited chronic GVHD had a positive impact on OS after CBT and MDT, but not after PTCy-haplo. In conclusion, mild acute GVHD improved outcomes after PTCy-haplo and CBT, and limited chronic GVHD improved outcomes after CBT and MDT. These data indicated that the effects of GVHD on transplant outcomes depended on transplant platforms.

Single Cord Blood Transplantation Versus HLA-Haploidentical-related Donor Transplantation Using Posttransplant Cyclophosphamide in Patients With Hematological Malignancies

BACKGROUND

Unrelated cord blood (UCB) and haploidentical related donor transplantation using posttransplant cyclophosphamide (PTCy-haplo) have become alternative options to treat patients with hematological malignancies without a HLA-matched donor.

METHODS

We conducted a retrospective study using registry data from the Kyoto Stem Cell Transplantation Group for patients with hematological malignancies who received their first allogeneic hematopoietic cell transplantation using a single UCB unit (n = 460) or PTCy-haplo (N = 57) between 2013 and 2019.

RESULTS

We found that overall survival in the UCB group was comparable to that in the PTCy-haplo group (hazard ratio, 1.00; 95% confidence interval, 0.66-1.52), although neutrophil and platelet engraftment were significantly delayed. Nonrelapse mortality risk and the incidence of graft-versus-host disease in the UCB group were also comparable to those in the PTCy-haplo group. Although the relapse risk was similar between the UCB group and the PTCy-haplo group regardless of the disease risk, acute myeloid leukemia patients benefit from UCB transplant with a significantly lower relapse rate (hazard ratio, 0.38; 95% confidence interval, 0.18-0.76).

CONCLUSIONS

UCB transplant gives outcomes comparable to PTCy-haplo transplant, and both UCB and PTCy-haplo units are suitable as alternative donor sources for patients without an HLA-matched sibling or unrelated donor.

Improved trends in survival and engraftment after single cord blood transplantation for adult acute myeloid leukemia

Unrelated cord blood transplantation (CBT) is an alternative curative option for adult patients with acute myeloid leukemia (AML) who need allogeneic hematopoietic cell transplantation (HCT) but lack an HLA-matched related or unrelated donor. However, large-scale data are lacking on CBT outcomes for unselected adult AML. To investigate the trends of survival and engraftment after CBT over the past 22 years, we retrospectively evaluated the data of patients with AML in Japan according to the time period of CBT (1998-2007 vs 2008-2013 vs 2014-2019). A total of 5504 patients who received single-unit CBT as first allogeneic HCT for AML were included. Overall survival (OS) at 2 years significantly improved over time. The improved OS among patients in ≥ complete remission (CR)3 and active disease at CBT was mainly due to a reduction of relapse-related mortality, whereas among patients in first or second CR at CBT, this was due mainly to a reduction of non-relapse mortality. The trends of neutrophil engraftment also improved over time. This experience demonstrated that the survival and engraftment rate after CBT for this group has improved over the past 22 years.

Title: Prognostic factors of children and adolescents with T-cell acute lymphoblastic leukemia after allogeneic transplantation

Acute lymphoblastic leukemia (ALL) is the most common cancer during childhood, and some high-risk patients with ALL require hematopoietic stem cell transplantation (HSCT). Mainly due to small patient numbers, studies focusing specifically on children and adolescents with T-cell ALL (T-ALL) are limited. Using a nationwide registry, we retrospectively analyzed data from patients under 20 years old who underwent their first HSCT for T-ALL between 2000 and 2018. As a result, total 484 patients were included, and their median follow-up period was 6.9 years after HSCT for survivors. While patients receiving HSCT at first complete remission (CR) showed relatively good 5-year leukemia free survival (5yLFS, 73.5%), once relapse occurred, their prognosis was much worse (44.4%) even if they attained second remission again (p < 0.001). Among patients receiving HSCT at CR1, grade II-IV acute graft versus host disease was associated with worse overall and LFS than grade 0-I (5yLFS 69.5% vs 82.1%, p = 0.026) mainly due to high non-relapse mortality. Among those patients, patients receiving related bone marrow transplantation, unrelated bone marrow transplantation, or unrelated cord blood transplantation showed similar survival (5yLFS, 73.2%, 76.3%, and 77.0%, respectively). For patients undergoing cord blood transplantation at CR1, total-body irradiation-based myeloablative conditioning was associated with better 5yLFS than other conditioning regimens (85.4% vs 62.2%, p = 0.044), as it reduced the risk of relapse. These results indicate that relapsed patients have much less chance of cure, and that identifying patients who require HSCT for cure and offering them HSCT with optimal settings during CR1 are crucial for children and adolescents with T-ALL. This article is protected by copyright. All rights reserved.

The impact of GVHD on outcomes after adult single cord blood transplantation in European and Japanese populations

The impact of GVHD and graft-versus-leukemia effect in unrelated cord blood transplantation (UCBT) is controversial. In the Eurocord/ALWP EBMT and JSTCT/JDCHCT collaborative study, we evaluated the impact of GVHD on UCBT outcomes in Japanese and European registries. A total of 3,690 adult patients with acute leukemia who received their first single UCBT were included. A multivariate analysis of overall survival (OS) revealed a positive impact of grade II acute GVHD compared with grade 0-I GVHD, in the Japanese cohort (hazard ratio (HR), 0.81; P = 0.001), and an adverse impact in the European cohort (HR, 1.37; P = 0.007). A negative impact of grade III-IV acute GVHD on OS was observed regardless of registries. In the analysis of relapse, a positive impact of grade II acutes GVHD compared with grade 0-I GVHD was observed only in the Japanese cohort, regardless of disease risk. The positive impact of limited chronic GVHD on OS was observed only in the Japanese cohort. In conclusion, a positive impact of mild GVHD after a single UCBT was observed only in the Japanese cohort. This could explain the ethnic difference in UCBT outcomes and might contribute to the preference usage of UCBT in Japan.

Impact of donor types on reduced-intensity conditioning allogeneic stem cell transplant for mature lymphoid malignancies

We retrospectively compared the outcomes of reduced-intensity conditioning (RIC) transplantation from matched related donors (MRD; n = 266), matched unrelated donors (MUD; n = 277), and umbilical cord blood (UCB; n = 513) for mature lymphoid malignancies. The 3-year overall survival rates for the MRD, MUD, and UCB groups were 54%, 59%, and 40%, respectively (P < 0.001). Multivariate analysis showed no differences in survival between the MRD group and the MUD or UCB group. However, survival was significantly affected by the conditioning regimen and graft-versus-host disease (GVHD) prophylaxis in the UCB group, but not in the MRD and MUD groups. Notably, multivariate analysis showed that the risk of overall mortality in the UCB recipients who received the optimal conditioning regimen and GVHD prophylaxis (n = 116) was lower than that in the MRD group (relative risk [RR], 0.69; P = 0.03) and tended to be lower than that in the MUD group (RR, 0.75; P = 0.09). Our results suggest that UCB transplantation performed with the optimal conditioning regimen and GVHD prophylaxis is highly effective. Moreover, UCB is readily available. Thus, UCB transplantation with the optimal conditioning regimen and GVHD prophylaxis is preferable to MUD transplantation when MRD are not available in the setting of RIC transplantation for mature lymphoid malignancies.

Guidelines for the Prevention and Management of Graft-versus-Host Disease after Cord Blood Transplantation

The incidence of graft-versus-host disease (GVHD) after cord blood (CB) transplantation (CBT) is lower than expected given the marked degree of human leukocyte antigen (HLA)-mismatch of CB grafts. While the exact mechanism that underlies this biology remains unclear, it is hypothesized to be due to the low number of mostly immature T-cells infused as part of the graft1,2, and increased tolerance of CB-derived lymphocytes induced by the state of pregnancy. Nevertheless, acute GVHD (aGVHD) is a significant complication of CBT. In contrast, the incidence of chronic GVHD (cGVHD) following CBT is lower than what is observed following matched related or unrelated donor HSC transplantation (HSCT)3-6. This review outlines the guidelines for the prevention and management of acute and chronic GVHD following CBT.

Differential Effect of Graft-versus-Host Disease on Survival in Acute Leukemia according to Donor Type

PURPOSE

The anti-leukemic activity of allogeneic hematopoietic cell transplantation (HCT) depends on both the intensity of conditioning regimen and the strength of the graft-versus-leukemia (GVL) effect. However, it is unclear whether the sensitivity of the GVL effects differs between donor type and graft source.

EXPERIMENTAL DESIGN

We retrospectively evaluated the effect of acute and chronic graft-versus-host disease (GVHD) on transplant outcomes for adults with acute leukemia (n = 6,548) between 2007 and 2017 using a Japanese database. In all analyses, we separately evaluated three distinct cohorts based on donor type [(8/8 allele-matched sibling donor, 8/8 allele-matched unrelated donor, and unrelated single-cord blood (UCB)].

RESULTS

The multivariate analysis, in which the development of GVHD was treated as a time-dependent covariate, showed a reductive effect of grade I-II acute GVHD on treatment failure (defined as 1-leukemia-free survival; P < 0.001), overall mortality (OM; P < 0.001), relapse (P < 0.001), and non-relapse mortality (NRM; P < 0.001) in patients receiving from UCB. A reductive effect of limited chronic GVHD on treatment failure (P < 0.001), OM (P < 0.001), and NRM (P < 0.001) was also shown in patients receiving from UCB. However, these effects were not always shown in patients receiving from other donors. The beneficial effects of mild acute and chronic GVHD after UCB transplantation on treatment failure were noted relatively in subgroups of patients with acute myelogenous leukemia and a non-remission status.

CONCLUSIONS

These data suggested that the development of mild GVHD could improve survival after UCB transplantation for acute leukemia.

Prognostic impact of the dosage of methotrexate combined with tacrolimus for graft-versus-host disease prophylaxis after cord blood transplantation

The optimal dosage of methotrexate (MTX) for graft-versus-host disease (GVHD) prophylaxis after cord blood transplantation (CBT) has not been well elucidated. Therefore, we conducted a retrospective study comparing a mini-MTX group (5 mg/m² on day 1, 3 and 6) to a short-MTX group (10 mg/m² on day 1 and 7 mg/m² on day 3 and 6) after CBT. Sixty-three patients were classified as the mini-MTX group and 20 as the short-MTX group. The median time and cumulative incidence of neutrophil engraftment did not vary between the two groups. The cumulative incidence of grade 2-4 and grade 3-4 acute GVHD was similar in both groups. Overall survival in the mini-MTX group was significantly lower than in the short-MTX group (46.9% vs. 88.7% at 1 year, p < 0.01), contributing to higher non-relapse mortality (NRM) in the mini-MTX group (32.0% vs. 5.0% at 1 year, p = 0.02). In multivariate analysis, the mini-MTX regimen was the most powerful prognostic factor for OS (hazard ratio 4.11; p = 0.03). Although the reduced dosage of MTX had no effect on neutrophil engraftment, increased NRM due to higher incidence of infection, graft failure, and severe acute GVHD resulted in a lower survival rate in the mini-MTX group after CBT.

A risk score system for stratifying the risk of relapse in B cell acute lymphocytic leukemia patients after allogenic stem cell transplantation

BACKGROUND

For patients with B cell acute lymphocytic leukemia (B-ALL) who underwent allogeneic stem cell transplantation (allo-SCT), many variables have been demonstrated to be associated with leukemia relapse. In this study, we attempted to establish a risk score system to predict transplant outcomes more precisely in patients with B-ALL after allo-SCT.

METHODS

A total of 477 patients with B-ALL who underwent allo-SCT at Peking University People's Hospital from December 2010 to December 2015 were enrolled in this retrospective study. We aimed to evaluate the factors associated with transplant outcomes after allo-SCT, and establish a risk score to identify patients with different probabilities of relapse. The univariate and multivariate analyses were performed with the Cox proportional hazards model with time-dependent variables.

RESULTS

All patients achieved neutrophil engraftment, and 95.4% of patients achieved platelet engraftment. The 5-year cumulative incidence of relapse (CIR), overall survival (OS), leukemia-free survival (LFS), and non-relapse mortality were 20.7%, 70.4%, 65.6%, and 13.9%, respectively. Multivariate analysis showed that patients with positive post-transplantation minimal residual disease (MRD), transplanted beyond the first complete remission (≥CR2), and without chronic graft-versus-host disease (cGVHD) had higher CIR (P  < 0.001, P = 0.004, and P  < 0.001, respectively) and worse LFS (P  < 0.001, P = 0.017, and P  < 0.001, respectively), and OS (P  < 0.001, P = 0.009, and P  < 0.001, respectively) than patients without MRD after transplantation, transplanted in CR1, and with cGVHD. A risk score for predicting relapse was formulated with the three above variables. The 5-year relapse rates were 6.3%, 16.6%, 55.9%, and 81.8% for patients with scores of 0, 1, 2, and 3 (P  < 0.001), respectively, while the 5-year LFS and OS values decreased with increasing risk score.

CONCLUSION

This new risk score system might stratify patients with different risks of relapse, which could guide treatment.

Favorable Outcomes after Single Cord Blood Transplantation for Patients with High-Risk Hematologic Diseases: A Single-Institute Retrospective Analysis

The donor selection algorithm for cord blood (CB) with regards to matched related and unrelated donors has not been fully investigated. To assess the potential of CB transplantation (CBT) in patients with hematologic malignancies, especially for high-risk patients, we performed a single-institute retrospective analysis and compared the clinical outcomes of CBT with those of HLA-matched sibling and unrelated donor transplantation. We included 394 patients aged 16 years and older with hematologic diseases who received their first allogeneic hematopoietic cell transplantation between 1990 and 2018 at Kyoto University Hospital. These included 394 recipients of single unrelated cord blood units (UCB, n = 108), HLA-matched sibling donors (MSDs, n = 143), or HLA-matched unrelated donors (MUDs, n = 143). There was no significant difference in relapse-free survival (RFS) between UCB, MSD, and MUD recipients (P = .975). However, we found a significant interaction between transplant year and CBT outcomes (P = .010), with significantly better outcomes observed in the more recent years. Furthermore, we found that CBT showed better RFS than matched donor transplantation (hazard ratio [HR], 0.50; 95% confidence interval [CI], 0.30 to 0.84). This impact was more prominent in high-risk patients (HR, 0.35; 95% CI, 0.16 to 0.77), with lower relapse rates (HR, 0.25; 95% CI, 0.11 to 0.54), and comparable non-relapse mortality (NRM) compared to matched donor transplantation. Extensive chronic graft-versus-host disease was less frequently observed in CBT (HR, 0.58; 95% CI, 0.26 to 1.28). CBT associated with favorable outcomes, particularly in high-risk patients, with good RFS and low relapse rates without an increase in NRM in the single-institute study. Although the findings should be externally validated, CBT might serve as a reasonable donor choice, particularly in high-risk patients.

Effect of methotrexate dose in graft-versus-host disease prophylaxis after single-unit cord blood transplantation in adult acute myeloid leukemia

To investigate the association between methotrexate (MTX) dosage and engraftment, graft-versus-host disease (GVHD) incidence, and survival in umbilical cord blood transplantation (UCBT), we compared transplant outcomes after UCBT with various GVHD prophylaxis regimens, using registry data with additional data collection. Patients transplanted for acute myeloid leukemia with a calcineurin inhibitor (CNI) and either MTX or mycophenolate mofetil (MMF) combination were selected. In total, 888 single-unit UCBTs (MTX_15-10-10, 415; MTX_10-7-7, 294; MTX_5-5-5, 71; MMF, 108) were included. In multivariate analyses with MTX_15-10-10 as the reference, the likelihood of neutrophil and platelet engraftment was significantly worse in the MTX_10-7-7 group, and similarly better in MMF group compared with MTX_15-10-10. All variables including CyA vs Tac and 4-group GVHD prophylaxis became significant for the risk of grade II-IV acute GVHD in the final multivariate model. We observed significant additional effects of combined MTX dose in the Tac group, which were larger with lower MTX dose and MMF. No significant difference was observed in survival risk among GVHD prophylaxis groups. Despite the potential background differences in the combined CNI and conditioning regimen, we conclude that the recommended GVHD prophylaxis is a combination of CyA plus MTX_15-10-10 or Tac plus MMF.

High progression-free survival after intermediate intensity double unit cord blood transplantation in adults

Cord blood transplantation (CBT) after high intensity or nonmyeloablative conditioning has limitations. We investigated cyclosporine-A/mycophenolate mofetil-based intermediate intensity (cyclophosphamide 50 mg/kg, fludarabine 150 mg/m2, thiotepa 10 mg/kg, total body irradiation 400 cGy) unmanipulated double-unit CBT (dCBT) with prioritization of unit quality and CD34+ cell dose in graft selection. Ninety adults (median age, 47 years [range, 21-63]; median hematopoietic cell transplantation comorbidity index, 2 [range, 0-8]; 61 [68%] acute leukemia) received double-unit grafts (median CD34+ cell dose, 1.3 × 105/kg per unit [range, 0.2-8.3]; median donor-recipient human leukocyte antigen (HLA) match, 5/8 [range 3-7/8]). The cumulative incidences of sustained CB engraftment, day 180 grade III-IV acute, and 3-year chronic graft-versus-host disease were 99%, 24%, and 7%, respectively. Three-year transplant-related mortality (TRM) and relapse incidences were 15% and 9%, respectively. Three-year overall survival (OS) is 82%, and progression-free survival (PFS) is 76%. Younger age and higher engrafting unit CD34+ cell dose both improved TRM and OS, although neither impacted PFS. Engrafting unit-recipient HLA match was not associated with any outcome with a 3-year PFS of 79% in 39 patients engrafting with 3-4/8 HLA-matched units. In 52 remission acute leukemia patients, there was no association between minimal residual disease (MRD) and 3-year PFS: MRD negative of 88% vs MRD positive of 77% (P = .375). Intermediate intensity dCBT is associated with high PFS. Use of highly HLA mismatched and unmanipulated grafts permits wide application of this therapy, and the low relapse rates support robust graft-versus-leukemia effects even in patients with MRD.

Randomised controlled trial of conditioning regimen for cord blood transplantation for adult myeloid malignancies comparing high-dose cytarabine/cyclophosphamide/total body irradiation with versus without G-CSF priming: G-CONCORD study protocol

INTRODUCTION

A better long-term quality of life after umbilical cord blood transplantation (CBT) is observed compared with transplants from other alternative donors, whereas graft failure and relapses after CBT are still major issues. To minimise graft failure and relapse after CBT, intensification of conditioning by the addition of high-dose cytosine arabinoside (CA) and concomitant continuous use of granulocyte-colony stimulating factor (G-CSF) are reported to convey a significantly better survival after CBT in some retrospective studies. To confirm the effect of G-CSF plus CA combination, in addition to the standard conditioning regimen, cyclophosphamide (CY)/total body irradiation (TBI), we design a randomised controlled study comparing CA/CY/TBI with versus without G-CSF priming (G-CSF combined conditioned cord blood transplantation [G-CONCORD] study).

METHODS AND ANALYSIS

This is a multicentre, open-label, randomised phase III study that aimed to compare G-CSF+CA/CY/TBI as a conditioning regimen for CBT with CA/CY/TBI. Patients with acute myeloid leukaemia or myelodysplastic syndrome, aged 16-55 years, are eligible. The target sample size is 160 and the registration period is 4 years. The primary endpoint is the 2-year disease-free survival rate after CBT. The secondary endpoints are overall survival, relapse, non-relapse mortality, acute and chronic graft-versus-host disease, engraftment rate, time to neutrophil recovery, short-term adverse events, incidence of infections and causes of death.This study employs a single one-to-one web-based randomisation between the with-G-CSF versus without-G-CSF groups after patient registration. Combination of high-dose CA and CY/TBI in both groups is used for conditioning.

ETHICS AND DISSEMINATION

The study protocol was approved by the central review board, Nagoya University Certified Review Board, after the enforcement of the Clinical Trials Act in Japan. The manuscripts presenting data from this study will be submitted for publication in quality peer-reviewed medical journals. Study findings will be disseminated via presentations at national/international conferences and peer-reviewed journals.

TRIAL REGISTRATION NUMBERS

UMIN000029947 and jRCTs041180059.

Effect of allogeneic HCT from unrelated donors in AML patients with intermediate- or poor-risk cytogenetics: a retrospective study from the Japanese Society for HCT

This study aimed to analyze the factors associated with outcomes of bone marrow transplantation (UR-BMT) or cord blood stem cell transplantation from unrelated donors (UR-CBT). We assessed the time from diagnosis to transplantation among acute myeloid leukemia (AML) patients with intermediate- or poor-risk cytogenetics to identify the potential clinical efficacy of transplantation. We retrospectively analyzed 5331 patients who received UR-BMT or UR-CBT between 2008 and 2017. Patients were divided into four groups according to time from diagnosis to transplantation: (1) UR-BMT and > 5 months (n = 2353), (2) UR-BMT and ≤ 5 months (n = 379), (3) UR-CBT and > 5 months (n = 1494), and (4) UR-CBT and ≤ 5 months (n = 1106). There was no difference in overall survival (OS) for transplantation at ≤5 months and > 5 months in patients with first complete remission for both UR-BMT and UR-CBT, but OS in patients with primary induction failure (PIF) and transplantation at ≤ 5 months was significantly higher in the UR-CBT group compared with that at >5 months (P < 0.001). Multivariate Cox regression analysis also showed that transplantation at >5 months in patients with PIF was an independent predictor of poorer OS. Therefore, UR-CBT at ≤ 5 months after diagnosis is an alternative option for AML patients with PIF.

Effects of Acute and Chronic Graft-versus-myelodysplastic Syndrome on Long-term Outcomes Following Allogeneic Hematopoietic Cell Transplantation

PURPOSE

Potent graft-versus-tumor (GVT) effects associated with graft-versus-host disease (GVHD) might be dependent on hematologic disease type and status. However, the data regarding the impact of GVHD on transplant outcomes for patients with myelodysplastic syndrome (MDS) are limited.

EXPERIMENTAL DESIGN

We retrospectively evaluated the impact of acute and chronic GVHD on transplant outcomes for a large cohort of adult patients with a low-risk (n = 1,193) and high-risk (n = 1,926) MDS treated by first allogeneic hematopoietic cell transplantation between 2001 and 2017.

RESULTS

The multivariate analysis, in which development of GVHD was treated as a time-dependent covariate, showed that acute and chronic GVHD at any grade or severity did not improve overall mortality, relapse, or nonrelapse mortality (NRM) in low-risk MDS. For patients with high-risk MDS, development of limited chronic GVHD was significantly associated with lower overall mortality [HR, 0.66; 95% confidence interval (CI), 0.50-0.86; P = 0.002]. This is probably due to that the reduced risk of relapse with grade III-IV acute GVHD (HR, 0.41; 95% CI, 0.25-0.65; P = 0.0002), or limited (HR, 0.57; 95% CI, 0.39-0.83; P = 0.003) or extensive (HR, 0.56; 95% CI, 0.41-0.77; P = 0.0004) chronic GVHD was offset by increased NRM with grade III-IV acute GVHD or extensive chronic GVHD in high-risk MDS.

CONCLUSIONS

These data demonstrated a survival benefit of the graft-versus-MDS effect is present only in high-risk MDS patients with limited chronic GVHD.See related commentary by Eckel and Deeg, p. 6404.

Soluble Interleukin-2 Receptor Index Predicts Outcomes After Cord Blood Transplantation

BACKGROUND

Our previous study demonstrated that the soluble interleukin-2 receptor (sIL-2R) index, defined as the ratio of serum sIL-2R levels at neutrophil engraftment to that before conditioning, is a biomarker that can predict acute graft-vs-host disease (GVHD) after unrelated bone marrow transplantation. In the present study, we evaluated the significance of the sIL-2R index among patients who underwent cord blood transplantation (CBT).

METHODS

We retrospectively analyzed 31 patients who underwent single-unit CBT as their first transplantation for hematologic malignancies.

RESULTS

The median sIL-2R index was 4.2. The cumulative incidence of grade II to IV acute GVHD was not associated with the sIL-2R index. However, the cumulative incidence of relapse at 3 years after transplantation was significantly lower, with an sIL-2R index ≥ 3.7 than with an index < 3.7 (12.8% vs 50.0%; P = .04). As a result, the probability of overall survival at 3 years after transplantation was significantly higher in the former group than in the latter (79.8% vs 20.0%; P < .01). Only the dose of corticosteroid administered in the pre-engraftment period influenced the sIL-2 index.

CONCLUSION

The sIL-2R index can predict the incidence of relapse and probability of survival after CBT, possibly reflecting a graft-vs-leukemia effect.

Favorable Effect of Cytomegalovirus Reactivation on Outcomes in Cord Blood Transplant and Its Differences Among Disease Risk or Type

The effects of cytomegalovirus (CMV) reactivation on cord blood transplant (CBT) are unclear. We assessed the effect of CMV reactivation in adult single-unit CBT without in vivo T cell depletion. Of 3147 eligible cases, 2052 were acute myeloid leukemia (AML), 643 acute lymphoblastic leukemia (ALL), and 452 myelodysplastic syndrome (MDS). CMV reactivation up to 100 days after CBT was associated with better overall survival (OS) compared with no reactivation cases (57.3% versus 52.6% at 3 years after CBT), whereas nonrelapse mortality (NRM) was increased in ALL (16.2% versus 8.9%) and standard disease risk (17.1% versus 10.6%, P = .014) by CMV reactivation. On multivariate analysis, CMV reactivation had favorable effects on relapse in MDS (hazard ratio [HR], .55; P = .044) and high disease risk (HR, .77; P = .047). In NRM, only standard-risk cases showed adverse effects of CMV reactivation (HR, 1.56; P = .026). OS was significantly improved with CMV reactivation in a subgroup of patients with AML (HR, .84; P = .044), MDS (HR, .68; P = .048), and high disease risk (HR, .81; P = .013). This favorable effect of CMV reactivation on OS in AML and high disease risk cases was maintained even after considering the effect of grades II to IV acute graft-versus-host disease. Thus, CMV reactivation might have beneficial or adverse effects on relapse, NRM, and OS, depending on the disease type or disease risk.

Effect of graft-versus-host disease on outcomes after pediatric single cord blood transplantation

The effect of GVHD on transplant outcomes after unrelated cord blood transplantation (UCBT) is not yet fully understood. Pediatric patients aged 0-15 years with acute leukemia or myelodysplastic syndrome who underwent their first UCBT (n = 740) were selected from the Japanese registry. Fifty percent of the patients received a UCB unit containing more than 5.0 × 10⁷/kg total nucleated cells. The occurrence of grade III-IV acute GVHD was associated with a higher risk of non-relapse mortality (NRM, hazard ratio [HR] 4.07, P < 0.001) compared with no acute GVHD. Grade I-II acute GVHD was not associated with NRM. The occurrence of grade I-II or grade III-IV acute GVHD was not associated with a relapse risk. These findings showed that grade I-II acute GVHD carried no survival benefit and grade III-IV acute GVHD had an adverse effect (HR 1.68, P = 0.007). The occurrence of limited chronic GVHD was associated with a low risk of overall mortality (HR 0.60, P = 0.045). Severe acute GVHD should be prevented because of its association with high overall mortality and NRM in pediatric single UCBT. Mild acute GVHD provides no overall benefit. Mild chronic GVHD may be beneficial for survival.

Impact of graft-versus-host disease and graft-versus-leukemia effect based on minimal residual disease in Philadelphia chromosome-positive acute lymphoblastic leukemia

The impacts of graft-versus-host disease (GVHD) and graft-versus-leukemia (GVL) effect might differ depending on minimal residual disease (MRD). Therefore, we examined 1,022 recipients who underwent their first allogeneic hematopoietic stem cell transplantation (HSCT) for Philadelphia chromosome-positive acute lymphoblastic leukemia (Ph-positive ALL) in first complete remission. MRD status at HSCT was negative in 791 (77·4%) and positive in 231 (22·6%). The impact of GVHD as a time-dependent covariate on transplant outcomes were analyzed while adjusting for other possible variables. Mild acute GVHD [hazard ratio (HR), 0·90; 95% confidence interval (CI), 0·70-1·16; P = 0·901] and chronic GVHD (HR, 0·82, 95% CI, 0·58-1·14; P = 0·238) were not significantly associated with overall mortality, whereas severe acute GVHD (HR, 2·26, 95% CI, 1·64-3·11; P < 0·001) resulted in inferior overall survival due to high non-relapse mortality. Moreover, even in the subgroup analyses stratified according to MRD status, acute and chronic GVHD were not significantly associated with better overall survival. Therefore, less intensive GVHD prophylaxis to achieve a GVL effect is not recommended for Ph-positive ALL.

Impact of graft-versus-host disease on the clinical outcome of allogeneic hematopoietic stem cell transplantation for non-malignant diseases

The impact of acute and chronic graft-versus-host disease (GVHD) on clinical outcomes was retrospectively analyzed in 960 patients with non-malignant diseases (NMD) who underwent a first allogeneic hematopoietic stem cell transplantation (HSCT). Grade III-IV acute GVHD (but not grade I-II) was significantly associated with a lower rate of overall survival (OS), and higher non-relapse mortality (NRM) than that seen in patients without acute GVHD. Extensive (but not limited) GVHD was significantly associated with a lower OS rate and higher NRM than that seen in patients without chronic GVHD. Any grade of acute (but not chronic) GVHD was significantly associated with a lower incidence of relapse and a lower proportion of patients requiring a second HSCT or donor lymphocyte infusion for graft failure or mixed chimerism, but its impact on OS was almost negligible. Acute GVHD was significantly associated with lower OS rates in all disease groups, whereas chronic GVHD was significantly associated with lower OS rates in the primary immunodeficiency and histiocytosis groups. In conclusion, acute and chronic GVHD, even if mild, was associated with reduced OS in patients receiving HSCT for NMD and effective strategies should, therefore, be implemented to minimize GVHD.

Post transplant cyclophosphamide based haplo-identical transplant versus umbilical cord blood transplant; a meta-analysis

OBJECTIVES

Both haplo-identical transplant (haplo) and umbilical cord transplant (UC) are valuable graft options for patients without available matched relative. Previous studies showed inconsistent outcomes comparing Post transplant Cyclophosphamide based haplo (PTCy-haplo) and UC; therefore, we attempt to compare the studies by mean of meta-analysis.

METHODS

We searched for titles of articles in MEDLINE (PubMed), Cochrane library, EMBASE database and Google scholar that compared transplantation with PTCy-haplo versus UC. We conducted a random-effect meta-analysis of seven studies involving a total of 3434 participants and reported the pooled odd ratios (OR) of acute graft-versus-host disease (aGVHD), chronic graft-versus-host disease (cGVHD), relapse and overall survival (OS) between PTCy-haplo and UC groups.

RESULTS

We found a significantly decreased risk of aGVHD and relapse in the PTCy-haplo group compared to the UC group with a pooled OR of 0.78, 95% Confidence Interval (CI) 0.67-0.92, I2=0%, and 0.74, 95% CI 0.57-0.97, I2=23.9% respectively. We also found a significantly increased rate of cGVHD and OS with a pooled OR of 1.41, 95% CI 1.02-1.95, I2=56.8%, and 1.77, 95% CI 1.1-2.87, I2=82.5%, respectively.

CONCLUSION

Our meta-analysis of clinical trials demonstrated superior outcome from PTCy-haplo group compared to the UC group in terms of decreased rate of aGVHD and relapse as well as the increased rate of OS but inferior in terms of increased cGVHD risk compared to UC transplant.

Single cord blood transplantation in Japan; expanding the possibilities of CBT

Cord blood (CB) has been an alternative stem cell source for patients with a wide variety of hematological diseases. Cord blood confers the advantages of rapid availability and higher tolerance to two HLA antigen mismatches compared with unrelated donors, and this has increased opportunities for patients who do not have suitable donors or require urgent transplantation. Although the higher rate of engraftment failure remains a serious concern after cord blood transplantation (CBT), the mechanisms underlying this risk have gradually been clarified, which has helped to improve engraftment. Recent studies of CBT and other alternatives have reported comparable outcomes. Moreover, CBT shows promise even when patients are in a non-remission status, which may reflect the potent graft-versus-leukemia effect of CB. Here we compare the most recent outcomes of CBT with those of other stem cell sources and discuss the potential of CB and several outstanding issues that require resolution.

Risk Stratification and Prognosticators of Acute Myeloid Leukemia with Myelodysplasia-Related Changes in Patients Undergoing Allogeneic Stem Cell Transplantation: A Retrospective Study of the Adult Acute Myeloid Leukemia Working Group of the Japan Society for Hematopoietic Cell Transplantation

Although the prognosis of acute myeloid leukemia with myelodysplasia-related changes (AML-MRC) is worse than that of AML not otherwise specified (AML-NOS), transplantation outcomes and prognosticators of AML-MRC patients undergoing allogeneic stem cell transplantation (allo-SCT) remain unclear. Transplantation outcomes of AML-MRC (n = 4091) were compared with those of AML-NOS (n = 3964) in patients who underwent allo-SCT between 2003 and 2016 using a nationwide registration database. The 3-year overall survival (OS; 35.5% versus 50.6%) was lower and the relapse (42.3% versus 32.1%) and nonrelapse mortality (26.3% versus 22.0%) rates were higher in the AML-MRC group than in the AML-NOS group. Based on the hierarchical AML-MRC classification, myelodysplasia as the sole criterion was associated with better OS compared with AML-NOS, whereas monosomal or complex karyotype and -5/del(5q) were associated with poor OS. A history of myelodysplastic syndrome and -7/del(7q) did not affect OS. Accordingly, AML-MRC with complex karyotype or -5/del(5q) and that with monosomal karyotype were classified as intermediate and high risks, respectively, whereas the remaining cases were classified as low risk. The 3-year OS rates were 50.7%, 36.9%, and 13.8% in the low-, intermediate-, and high-risk groups, respectively (P < .001). Risk classification, older age, and low performance status score were significant risk factors for survival in AML-MRC, independently of the disease status. Grades I to II acute graft-versus-host disease significantly reduced the 3-year relapse (24.7% versus 31.6%), leading to better survival (hazard ratio, .64). Our prognostic risk stratification can potentially aid in elucidating the diverse transplantation outcomes in patients with AML-MRC.

Development of Pre-Engraftment Syndrome, but Not Acute Graft-versus-Host Disease, Reduces Relapse Rate of Acute Myelogenous Leukemia after Single Cord Blood Transplantation

The different effects of pre-engraftment syndrome (PES) and acute graft-versus-host disease (aGVHD) on outcomes after cord blood transplantation (CBT) are unclear. We retrospectively evaluated the impact of PES and aGVHD on relapse and survival after single-unit CBT in 138 adult patients with hematologic malignancies at our institution between 2004 and 2016. Multivariate analysis demonstrated that development of grade III-IV aGVHD, particularly with gut or liver involvement, significantly contributed to higher nonrelapse mortality (P < .001), but PES and grade II-IV aGVHD did not. In subgroup analyses of underlying disease type, the development of PES had a significant effect on decreased relapse (P = .032) and better disease-free survival (DFS) (P = .046) in patients with acute myelogenous leukemia (AML). These data suggest that PES is associated with a reduced relapse rate and better DFS in AML, indicating that the early immune reaction before neutrophil engraftment may provide a unique graft-versus-leukemia effect after single-unit CBT.

Development of Grade II Acute Graft-versus-Host Disease Is Associated with Improved Survival after Myeloablative HLA-Matched Bone Marrow Transplantation using Single-Agent Post-Transplant Cyclophosphamide

Post-transplant cyclophosphamide (PTCy) can be used as the sole immunosuppression after myeloablative conditioning (MAC) for HLA-matched bone marrow transplantation (BMT). However, the effects of graft-versus-host disease (GVHD) with this platform are undefined. We retrospectively analyzed 298 consecutive adult patients with hematologic malignancies who engrafted after MAC HLA-matched sibling donor (MSD; n = 187) or HLA-matched unrelated donor (MUD; n = 111) T-cell-replete BMT with PTCy 50 mg/kg on days +3 and +4. After MSD and MUD BMT, 35% and 57% of patients, respectively, developed grade II acute GVHD (aGVHD) by 100 days, 11% and 14% grade III to IV aGVHD by 100 days, and 9% and 16% chronic GVHD (cGVHD) by 1 year. In landmark analyses at 100 days after HLA-matched BMT, 4-year overall survival (OS) and progression-free survival (PFS) were 57% (95% confidence interval [CI], .49 to .67) and 40% (95% CI, .31 to .51) in patients without grades II to IV aGVHD, and 68% (95% CI, .59 to .78) and 54% (95% CI, .44 to .65) in patients with grade II aGVHD. In adjusted time-dependent multivariable analyses, grade II aGVHD was associated with improved OS (hazard ratio, .58; 95% CI, .37 to .89; P = .01) and PFS (hazard ratio, .50; 95% CI, .34 to .74; P < .001) after HLA-matched BMT with PTCy. The ability of PTCy to limit grades III to IV aGVHD and cGVHD while maintaining grade II aGVHD may contribute to its effectiveness, and further attempts to reduce aGVHD may be detrimental.

Second allogeneic hematopoietic cell transplantation enables long-term disease-free survival in relapsed acute leukemia

Allogeneic hematopoietic cell transplantation (HCT) is the treatment of choice for high-risk myeloid and lymphoid leukemias. Relapse after allogeneic HCT is associated with a dismal prognosis and further therapeutic options are limited. One potential curative approach is a second allogeneic HCT. However, there is no consensus about optimal transplant modalities, suitable patients, and entities. We performed a retrospective analysis of our institutional database to evaluate risk factors that influence survival after a second allogeneic HCT for the treatment of relapsed acute myeloid leukemia (AML) and acute lymphoblastic leukemia (ALL). We identified 40 patients (AML, n = 29; ALL, n = 11) that received a second allogeneic HCT at our institution. At time of second HCT, 48% of patients were in complete remission (CR). Current overall survival (OS) was 14/40 patients with a median follow-up of 64 months (range 4-140) of patients alive resulting in a Kaplan-Meier estimated 2-year event-free survival (EFS) and OS of 32%, respectively. Cumulative incidence of non-relapse mortality (NRM) and relapse at 2 years was 31 and 37%, respectively. We identified several independent risk factors influencing OS: > 6 months from first to second transplant (p = 0.02), complete remission prior to transplant (p = 0.003), and the subsequent occurrence of chronic graft-versus-host disease (p = 0.003) were associated with a significantly improved OS. In conclusion, our data suggest that a second allogeneic HCT is a curative treatment option for relapsed acute leukemias in selected patients.

Impact of graft-versus-host disease on relapse and survival after allogeneic stem cell transplantation for pediatric leukemia

Graft-versus-host disease (GVHD) occasionally leads to morbidity and mortality but is thought to reduce the risk of relapses in patients with a hematological malignancy. However, information on the effect of GVHD in pediatric leukemia is limited. Using a nationwide registry, we retrospectively analyzed 1526 children who underwent allogeneic stem cell transplantation for leukemia. Grades 0-I acute GVHD were associated with a higher relapse rate at three years after transplantation, at 25.4 and 24.3%, respectively, than grades II, III, or IV acute GVHD at 18.9%, 21.2%, and 2.6%, respectively. In contrast, the overall survival curve of the grades 0 and I GVHD groups (79.0% and 79.5%, respectively) approximated that of the grade II GVHD group (76.3%), and the probability of survival was worst in the severe GVHD groups (66.9% for grade III and 42.5% for grade IV). Chronic GVHD also reduced the relapse risk but conferred no survival advantage. Acute lymphoblastic leukemia was more sensitive to acute GVHD than acute myeloid leukemia (AML) while AML was more sensitive to chronic GVHD. Our study reproduced the preventive effects of GVHD against pediatric leukemia relapses but failed to demonstrate a significant survival advantage.

Occurrence of graft-versus-host disease increases mortality after umbilical cord blood transplantation for acute myeloid leukaemia: a report from Eurocord and the ALWP of the EBMT

BACKGROUND

The efficacy of umbilical cord blood transplantation (UCBT) as treatment for acute myeloid leukaemia (AML) relies on immune-mediated graft-versus-leukaemia effects. Previous studies have suggested a strong association between graft-versus-host disease (GVHD) occurrence and graft-versus-leukaemia effects after allogeneic hematopoietic cell transplantation.

METHODS

Here, we evaluated the kinetics of relapse rate in correlation with GVHD occurrence after UCBT. The kinetics of relapse rate over time in correlation to GVHD occurrence were assessed by calculating the relapse rate per patient-year within sequential 90-day intervals. The impact of GVHD on relapse and mortality was further studied in multivariate Cox models handling GVHD as a time-dependent covariate.

RESULTS

The study included data from 1068 patients given single (n = 567) or double (n = 501) UCBT. The proportion of patients with grade II, III and IV acute GVHD was 20%, 7% and 4%, respectively. At 2 years, the cumulative incidence of chronic GVHD was 42%, the cumulative incidence of relapse was 32%, and overall survival was 32% as well. Relapse rates declined gradually over time during the first 30 months after transplantation. There was a possible suggestion that grade II-IV acute (HR = 0.8, P = 0.1) and chronic (HR = 0.65, P = 0.1) GVHD decreased relapse risk. However, grade II-IV acute GVHD significantly increased early (the first 18 months after UCBT) mortality (HR = 1.3, P = 0.02), whilst chronic GVHD increased each early (HR = 2.7, P < 0.001) and late (HR = 4.9, P < 0.001) mortality after UCBT.

CONCLUSIONS

The occurrence of grade II-IV acute or chronic GVHD each increases overall mortality after UCBT for AML mitigating the possible graft-versus-leukemia effect of GVHD.

Grade II Acute Graft-versus-Host Disease and Higher Nucleated Cell Graft Dose Improve Progression-Free Survival after HLA-Haploidentical Transplant with Post-Transplant Cyclophosphamide

Compared with standard graft-versus-host disease (GVHD) prophylaxis platforms, post-transplantation cyclophosphamide (PTCy) after T cell-replete HLA-haploidentical (haplo) bone marrow transplantation (BMT) reduces the risk of grades III to IV acute (a) and chronic (c) GVHD, but maintains similar rates of grade II aGVHD. Given that mild GVHD has been associated with reduced treatment failure in HLA-matched BMT, we evaluated the risk factors for and effects of GVHD on survival in 340 adults with hematologic malignancies who engrafted after nonmyeloablative haplo-BMT with PTCy, mycophenolate mofetil, and tacrolimus. The cumulative incidence at 100 days of grade II and grades III to IV aGVHD were 30% (95% confidence interval [CI], 25% to 35%) and 2% (95% CI, 1% to 4%), respectively. The 1-year cumulative incidence of cGVHD was 10% (95% CI, 7% to 13%). In landmark analyses at 100 days, the 4-year probabilities of overall survival (OS) and progression-free survival (PFS) were, 48% (95% CI, 41% to 56%) and 39% (95% CI, 32% to 47%) for patients without grades II to IV aGVHD, compared with 63% (95% CI, 53% to 73%) and 59% (95% CI, 50% to 71%) for patients with grade II aGVHD (P = .05 and P = .009). In multivariable modeling, when compared with patients who never experienced GVHD, the hazard ratio (HR) for OS and PFS in patients with grade II aGVHD was .78 (95% CI, .54 to 1.13; P = .19) and .69 (95% CI, .48 to .98; P = .04). Higher nucleated cell graft dose was also associated with improved OS (HR, .88; 95% CI, .78 to 1.00; P = .05) and PFS (HR, .89; 95% CI, .79 to 1.0; P = .05) and decreased risk of grades III to IV aGVHD (subdistribution HR, .66; 95% CI, .46 to .96; P = .03). PTCy reduces grades III to IV aGVHD and cGVHD, but retains similar incidence of grade II aGVHD, the development of which improves PFS. Higher nucleated cell graft dose goals may also improve survival after nonmyeloablative haplo-BMT with PTCy.

Hematopoietic stem cell transplantation for acute myeloid leukemia

Although allogeneic hematopoietic stem cell transplantation (allo-HSCT) yields a high rate of curability for acute myeloid leukemia (AML), it is also associated with transplant-related morbidity and mortality (TRM). The risk and severity of TRM increase with the use of an alternative donor graft in the absence of an HLA-matched sibling donor (MSD). With the declining birthrate and aging of the population, the numbers of patients with an MSD are decreasing, and alternative donor transplants, including the post-transplant cyclophosphamide method using haplo-identical donors, are increasing. Autologous (auto)-HSCT, which enables the intensification of chemotherapy, has the advantage of high availability of a transplant graft, and is associated with a lower TRM, but these benefits may be offset by a higher rate of relapse due to the lack of a graft-versus-leukemia (GVL) effect. Although allo-HSCT remains the first-line treatment for poor and very-poor-risk patients, auto-HSCT is again gaining increased attention. It has also recently been suggested that cord blood grafts may induce a stronger GVL effect than other grafts; as such, the positioning of cord blood transplantation should also be reconsidered for AML patients.

Phase II study of intrabone single unit cord blood transplantation for hematological malignancies

The outcomes of cord blood transplantation with non‐irradiated reduced‐intensity conditioning for hematological malignancies need to be improved because of graft failure and delayed engraftment. Intrabone infusion of cord blood cells has the potential to resolve the problems. In this phase II study, 21 adult patients with hematological malignancy received intrabone transplantation of serological HLA‐A, B, and DR ≥4/6 matched single cord blood with a median number of cryopreserved total nucleated cells of 2.7 × 10⁷/kg (range, 2.0–4.9 × 10⁷/kg) following non‐irradiated fludarabine‐based reduced‐intensity conditioning. Short‐term methotrexate and tacrolimus were given as graft‐versus‐host disease prophylaxis, and granulocyte colony‐stimulating factor was given after transplantation. No severe adverse events related to intrabone injection were observed. The cumulative incidences of neutrophils ≥0.5 × 10⁹/L, reticulocytes ≥1%, and platelets ≥20 × 10⁹/L recoveries were 76.2%, 71.4%, and 76.2%, respectively, with median time to recoveries of 17, 28, and 32 days after transplantation, respectively. The probability of survival with neutrophil engraftment on day 60 was 71.4%, and overall survival at 1 year after transplantation was 52.4%. The incidences of grade II–IV and III–IV acute graft‐versus‐host disease were 44% and 19%, respectively, with no cases of chronic graft‐versus‐host disease. The present study showed the safety of direct intrabone infusion of cord blood. Further analysis is required to confirm the efficacy of intrabone single cord blood transplantation with non‐irradiated reduced‐intensity conditioning for adult patients with hematological malignancy. This study was registered with UMIN‐CTR, number 000000865.

HLA-DPB1 mismatch induces a graft-versus-leukemia effect without severe acute GVHD after single-unit umbilical cord blood transplantation

Although it is known that human leukocyte antigen (HLA)-DPB1 disparity has a strong impact on outcomes in unrelated hematopoietic transplantation with induction of acute graft-versus-host disease (GVHD) and a graft-versus-leukemia (GVL) effect, its role in unrelated umbilical cord blood transplantation (UR-CBT) has yet to be fully clarified. Our current study is being conducted to elucidate the impact of HLA-DPB1 mismatch, along with the effect of other HLA loci mismatches at the allele level. HLA six loci alleles were retrospectively typed in 1157 Japanese donors and patients with leukemia or myelodysplastic syndrome who underwent transplantation with a single unit of cord blood. HLA-DPB1 mismatch was associated with a significant reduction in leukemia relapse (hazard ratio 0.61, P<0.001), whereas the other HLA loci allele-level mismatches did not. No significant effect of HLA-DPB1 mismatch was observed in the risk of acute GVHD, engraftment or mortality. This HLA-DPB1 GVL effect without induction of severe acute GVHD or deterioration of survival rate has not been reported in unrelated bone marrow or peripheral blood stem cell transplantations, suggesting apparent advantages of UR-CBT. Accordingly, selection of an HLA-DPB1 mismatch cord blood might be the preferable choice for single-unit UR-CBT.

Single umbilical cord blood with or without CD34+ cells from a third-party donor in adults with leukemia

We retrospectively compared the clinical outcomes of adults with acute leukemia who received single-unit umbilical cord blood (UCB) transplantation (sUCBT) (n = 135) or stem cell transplant using coinfusion of a UCB graft with CD34⁺ cells from a third-party donor (Haplo-Cord) (n = 72) at different institutions within the Grupo Español de Trasplante Hematopoyético. In multivariable analysis, patients in the Haplo-Cord group showed more rapid neutrophil (hazard ratio [HR], 2.3; 95% confidence interval [CI], 1.5-3.3; P < .001) and platelet recovery (HR, 1.6; 95% CI, 1.2-2.3; P = .015) and lower incidence of chronic graft-versus-host disease (GVHD) (relative risk, 0.5; 95% CI, 0.3-0.8; P = .01). Nonrelapse mortality, relapse, disease-free survival (DFS), and GVHD/relapse-free survival were similar in the 2 groups. Regarding disease-specific outcomes, DFS in both acute myeloid leukemia (AML) and acute lymphoblastic leukemia patients was not significantly different; however, a significantly higher relapse rate was found in patients with AML treated with Haplo-Cord (HR, 2.3; 95% CI, 1-5.4; P = .04). Our study confirms that Haplo-Cord was an effective strategy to accelerate neutrophil and platelet recovery and shows that, in the context of specific treatment platforms, sUCBT and Haplo-Cord offer similar long-term outcomes.