Double Umbilical Cord Blood Units Research Articles

Higher survival following transplantation with a mismatched unrelated donor with posttransplant cyclophosphamide-based graft-versus-host disease prophylaxis than with double unit umbilical cord blood in patients with acute myeloid leukemia in first complete remission: A study from the Acute Leukemia Working Party of the European Society for Blood and Marrow Transplantation.

The best donor option for acute myeloid leukemia (AML) patients lacking an HLA-matched donor has remained intensively debated. We herein report the results of a large retrospective registry study comparing hematopoietic cell transplantation (HCT) outcomes between double-unit umbilical cord blood transplantation (dCBT, n = 209) versus 9/10 HLA-matched unrelated donor (UD) with posttransplant cyclophosphamide (PTCy)-based graft-versus-host disease (GVHD) prophylaxis (UD 9/10, n = 270) in patients with AML in first complete remission (CR1). Inclusion criteria consisted of adult patient, AML in CR1 at transplantation, either peripheral blood stem cells (PBSC) from UD 9/10 with PTCy as GVHD prophylaxis or dCBT without PTCy, transplantation between 2013 and 2021, and no in vivo T-cell depletion. The 180-day cumulative incidence of grade II-IV acute GVHD was 29% in UD 9/10 versus 44% in dCBT recipients (p = .001). After adjustment for covariates, dCBT recipients had a higher non-relapse mortality (HR = 2.35, 95% CI: 1.23-4.48; p = .01), comparable relapse incidence (HR = 1.12, 95% CI: 0.67-1.86; p = .66), lower leukemia-free survival (HR = 1.5, 95% CI: 1.01-2.23; p = .047), and lower overall survival (HR = 1.66, 95% CI: 1.08-2.55; p = .02) compared with patients receiving UD 9/10 HCT. In summary, our results suggest that transplantation outcomes are better with UD 9/10 with PTCy-based GVHD prophylaxis than with dCBT for AML patients in CR1. These data might support the use of UD 9/10 with PTCy-based GVHD prophylaxis over dCBT in AML patients lacking an HLA-matched donor.

Mismatched Unrelated Donor Transplantation with Ptcy-Based Gvhd Prophylaxis Is Associated with Better Survival Than Double Unit Umbilical Cord Blood Transplantation in Patients with AML in First CR: A Study from the ALWP of the EBMT

Background: The best donor option for acute myeloid leukemia (AML) patients lacking an HLA-matched donor has remained unknown. The recently reported BNT CTN 1101 trial observed higher non-relapse mortality (NRM) and lower overall survival (OS) in patients randomized to double-unit unrelated umbilical cord blood transplantation (dCBT) in comparison to those randomized to HLA-haploidentical bone marrow transplantation with post-transplant cyclophosphamide (PTCy)-based graft-versus-host disease (GVHD) prophylaxis 1. In addition, recent registry studies observed at least as good transplantation outcomes in AML patients given grafts from 9/10 HLA-matched unrelated donor (UD 9/10) with PTCy-based GVHD prophylaxis as those given grafts from HLA-haploidentical donors 2,3. These observations prompted us to perform a retrospective registry study comparing hematopoietic cell transplantation (HCT) outcomes between UD 9/10 and dCBT. Methods: Inclusion criteria consisted of adult patient, AML in CR1 at transplantation, either peripheral blood stem cells (PBSC) from UD 9/10 with PTCy as GVHD prophylaxis or dCBT, transplantation between 2013 and 2021, and no in vivo T-cell depletion. Results: A total of 208 dCBT patients and 270 UD 9/10 allo-HCT were included. The 180-day cumulative incidence of grade II-IV acute GVHD was 29% in UD 9/10 versus 44% in dCBT recipients (P=0.001). The 2-year cumulative incidences of relapse and of NRM were 23.5% and 12.5%, respectively, in UD 9/10 recipients versus 27% (P=0.39) and 18% (P=0.07), respectively in dCBT recipients. Two-year OS and LFS were 70% and 64%, respectively, in UD 9/10 recipients versus 60% (P=0.016) and 55% (P=0.028), respectively in dCBT recipients. In multivariate analyses, in comparison with UD 9/10 recipients, dCBT patients had a higher non-relapse mortality (HR=2.35, 95% CI: 1.23-4.48; P=0.01), comparable relapse incidence (HR=1.12, 95% CI: 0.67-1.86; P=0.66), lower leukemia-free survival (HR=1.5, 95% CI: 1.01-2.23; P=0.047), and lower overall survival (HR=1.66, 95% CI: 1.08-2.55; P=0.02). Conclusions: In summary, our results suggest that transplantation outcomes are better with UD 9/10 with PTCy-based GVHD prophylaxis than with dCBT for AML patients in CR1. These data might support the use of UD 9/10 with PTCy-based GVHD prophylaxis in AML patients lacking an HLA-matched donor. References Fuchs, E. J. et al. Double unrelated umbilical cord blood vs HLA-haploidentical bone marrow transplantation: the BMT CTN 1101 trial. Blood 137, 420-428 (2021).Baron, F. et al. Comparison of HLA-mismatched unrelated donor transplantation with post-transplant cyclophosphamide versus HLA-haploidentical transplantation in patients with active acute myeloid leukemia. Bone Marrow Transplant. 57, 1657-1663 (2022).Battipaglia, G. et al. Post-transplant cyclophosphamide in one-antigen mismatched unrelated donor transplantation versus haploidentical transplantation in acute myeloid leukemia: a study from the Acute Leukemia Working Party of the EBMT. Bone Marrow Transplant. 57, 562-571 (2022).

Abstract 7 Reduced Intensity Conditioning Umbilical Cord Blood Transplantation in Combination with Splenic Irradiation in a Patient with Secondary Myelofibrosis and Massive Splenomegaly

IntroductionMyelofibrosis (MF) is a bone marrow neoplasm characterized by marrow fibrosis/failure and splenomegaly, causing pain, early satiety, and cytopenia. The only curative option is allogeneic hematopoietic stem cell transplant (allo-HSCT); however, its use is limited due to donor availability and patient age, functional status, and comorbidities. Umbilical cord blood (UCB) has been explored in this population for this reason with variable success, partly related to splenomegaly, which might influence engraftment in MF patients.ObjectiveThe objective was to report the successful use of UCB transplantation in conjunction with splenic irradiation to treat a patient with advanced MF and massive splenomegaly.MethodsA 71-year-old male with post-essential thrombocythemia MF was treated with ruxolitinib for 2 years but developed worsening cytopenia and transfusion dependence. Splenomegaly (19.1×7.1×20.8 cm) was identified. Allo-HSCT was recommended on the basis of high-risk disease (DIPSS Plus score: 4) and few alternative options. Although suitable HLA-matched donors were unattainable, two cord blood units were available. A reduced intensity conditioning regimen of fludarabine, cyclophosphamide, and TBI 300 was chosen. Given the primary resistance to ruxolitinib, the spleen was irradiated with 450 cGy prior to transplant.ResultsNeutrophil and platelet engraftment occurred on days +30 and +49, respectively. The patient developed engraftment syndrome and acute graft versus host disease (GVHD) that resolved with methylprednisolone and early introduction of ruxolitinib. His immunosuppressive medications were discontinued by 6-months without evidence of chronic GVHD thereafter. He is now 1 year post-transplant with 100% donor chimerism and no clinical evidence of MF or GVHD.DiscussionWe present a novel therapeutic approach combining the use of splenic irradiation and a double unit UCB HSCT in a patient with MF and massive splenomegaly. UCB transplant should be considered in patients with MF who do not have an HLA-matched donor with the additional benefit of less chronic GvHD. Massive splenomegaly can negatively impact transplant outcomes due to entrapment of donor stem cells, delayed engraftment, and prolonged cytopenia. Splenic irradiation before UCB transplant can potentially reduce these complications, as it did in this case, and in turn decrease transplant-related mortality. Our future aim is to develop a clinical trial to study this approach.

Comparison of Outcomes after Unrelated Double-Unit Cord Blood and Haploidentical Peripheral Blood Stem Cell Transplantation in Adults with Acute Myelogenous Leukemia: A Study on Behalf of Eurocord and the Acute Leukemia Working Party of the European Society for Blood and Marrow Transplantation

Unmanipulated haploidentical hematopoietic stem cell transplantation (HCT) with post-transplantation cyclophosphamide as graft-versus-host disease (GVHD) prophylaxis (haplo-PTCY) and unrelated double-unit umbilical cord blood transplantation (dUCBT) are feasible options for treating patients with high-risk acute myelogenous leukemia (AML). This study compared outcomes after dUCBT and haplo-HCT using peripheral blood stem cells (PBSCs) in adult patients with AML in complete remission (CR) who underwent transplantation in European Society for Blood and Marrow Transplantation (EBMT)-affiliated centers. In a population of adults with de novo AML in first or second CR, we compared outcomes after dUCBT (n = 165) and after haplo-PTCY PBSC (n = 544) performed between January 2013 and December 2018. Patients receiving in vivo antithymocyte globulin, Campath, or ex vivo T cell depletion were excluded. The median follow-up was 33 months for the haplo-PTCY arm and 52 months for the dUCBT arm. No statistically significant differences were observed between the 2 arms in the rates of grade II-IV acute graft-versus-host disease (GVHD) (hazard ratio [HR], 1.31; P = .18), grade III-IV acute GVHD (HR, 1.17; P = .56), chronic GVHD (HR, .86; P = .48), relapse (HR, 1.07; P = .77), nonrelapse mortality (NRM) (HR, .94; P = .77), leukemia-free survival (LFS) (HR, .99; P = .95), or overall survival (OS) (HR, .99; P = .97). Favorable cytogenetic risk was the sole factor predictive of lower relapse incidence (RI). Younger age at transplantation was associated with lower NRM and higher LFS and OS. Both dUCBT and haplo-PTCY with PBSCs can be considered valid approaches for adult AML patients in CR. New strategies should be investigated in both settings to define the most appropriate conditioning regimen and potentially decrease RI and NRM through better immune reconstitution and optimal supportive care.

Impact of Center Experience with Donor Type on Outcomes: A Secondary Analysis, Blood and Marrow Transplant Clinical Trials Network 1101

We previously reported the results of Blood and Marrow Transplant Clinical Trials Network (BMT CTN) 1101, a randomized comparison of hematopoietic cell transplantation (HCT) performed with double umbilical cord blood units (dUCB) or with haploidentical bone marrow (haplo-BMT) with post-transplantation cyclophosphamide (PTCy) in the nonmyeloablative setting. Those results showed similar progression-free survival in the 2 treatment groups but lower nonrelapse mortality and better overall survival in the haplo-BM arm. In this secondary analysis, we sought to investigate whether transplantation center's previous experience with haplo-BM and/or dUCB HCT had an impact on outcomes. All patients randomized in BMT CTN 1101 were included. Center experience was assigned based on the number of transplantations with each platform performed in the year before initiation of the study according to the Center for International Blood and Marrow Transplant Research. Centers were then classified as a dUCB center (>10 dUCB HCTs; n=117 patients, 10 centers), a haplo-BM center (>10 haplo-BM HCTs and ≤10 dUCB HCTs; n=110 patients, 2 centers), or other center (≤10 haplo and ≤10 dUCB HCTs; n=140 patients, 21 centers). After adjusting for age, Karnofsky Performance Status, and Disease Risk Index, we found that haplo-BM centers had lower overall mortality with this donor type compared with dUCB centers (hazard ratio [HR], 2.56; 95% confidence interval [CI], 1.44 to 4.56). In contrast, there were no differences in overall mortality between haplo-BM and dUCB in centers that were experienced with dUCB HCT (HR, 1.02; 95% CI, .59 to 1.79) or had limited to no experience with either dUCB or haplo-BM HCT (HR, 1.36; 95% CI, .83 to 2.21). The higher risk of treatment failure and overall mortality in dUCB HCT in haplo BM-experienced centers was driven by a significantly higher risk of relapse (HR, 1.78; 95% CI, 1.07 to 2.97). With the exception of worse outcomes among dUCB HCT recipients in haplo-BM centers, transplantation center experience in the year before initiation of BMT CTN 1101 had a limited impact on the outcomes of this randomized clinical trial.

Ruxolitinib for Treating Steroid-Refractory Acute Graft-Versus-Host Disease in an Infant with Malignant Osteopetrosis Who Received Double-Unit Umbilical Cord Blood Transplantation

A 3-month-old male infant was transferred to our hospital due to bicytopenia. His bone marrow biopsy showed irregular bony trabeculae with cartilaginous core, which was consistent with osteopetrosis. In the genetic test, c.242del (p.Pro81Argfs*85) in TCIRG1 was found to be homozygotic, thus he was diagnosed with malignant infantile osteopetrosis. At 6 months of age, he received double-unit umbilical cord blood transplantation (UCBT) with the conditioning regimen including busulfan, cyclophosphamide, and rabbit anti-thymocyte globulin. Initially, single UCB was infused to the patient, but the post infusion viability of the UCB was unexpectedly low. Thus, another UCB was additionally infused. Cyclosporine and mycophenolate mofetil were used for graft-versus-host disease (GVHD) prophylaxis. Neutrophils and platelets were engrafted on day +13 and +33, respectively. With engraftment, he showed overall grade 4 acute GVHD involving the skin and gut, which was refractory to corticosteroids. Despite treating with low-dose weekly methotrexate (10 mg/m2) and oral beclomethasone, his symptoms persisted. After treating with ruxolitinib 2.5 mg/day for 2 weeks, and 5 mg/day thereafter, his diarrhea stopped in 2 weeks and his skin symptoms gradually improved over 3 months. The short tandem repeats showed 100% donor chimerism at 1 and 3 months after UCBT. Currently, 4 months after UCBT, he is 10 months old. The oral prednisolone has been tapered to 0.6 mg/kg/day, and the dose of ruxolitinib was decreased to 2.5 mg/day without recurrence of GVHD. We plan to taper off the immunosuppressive agents if his GVHD symptoms do not recur. Keywords: Child, Cord blood stem cell transplantation, Graft vs host disease, Infant, Osteopetrosis

First-Line Unrelated Double-Unit Umbilical Cord Blood Transplantation for Acquired Severe Aplastic Anemia

We analyzed the outcomes of 14 patients with severe aplastic anemia (SAA) who received first-line double-unit cord blood transplantation (dUCBT). Patients' median age was 24.5 years (range, 10-44 years). The median numbers of infused nucleated and CD34+ cells were 5.48×107/kg (range, 3.33-7.96×107/kg) and 2.30×105/kg (range, 0.86-3.97×105/kg), respectively. One patient died 5 days after transplantation. Three of the 13 patients acquired autologous myeloid recovery. Neutrophil engraftment was observed in 10 patients (76.29%), and the median time of neutrophil recovery was 19 days (range, 15-40 days). Platelet engraftment was observed in 7 cases (53.8%), and 3 patients experienced platelet graft failure. The median time of platelet recovery was 32 days (range, 22-80 days). The cumulative incidence of grade II-IV acute graft-vs-host disease (GVHD) was 38.5%. One patient demonstrated mild chronic GVHD. After a median follow-up of 61 months (range, 18-102 months), 6 patients were alive. The predicted 5-year overall survival and GVHD-free, failure-free survival rates were 42.9% ± 13.2% and 14.3% ± 9.4%, respectively. The first-line dUCBT for SAA is still primarily evaluated through multicenter prospective clinical trials by an optimal conditioning regimen, cell dose, and other graft and transplantation-related factors.

Prognostic Value of Refined Disease Risk Index (rDRI) and Conditioning Regimen in Adult Patients Receiving Unrelated Cord Blood Transplantation (UCBT) for Haematological Malignancies - 15-Year Follow-up of Multicenter Study in Singapore

Introduction: Umbilical cord blood (UCB) is an established stem cell source for transplantation in patients with hematological diseases who lack suitable related or unrelated donors. Refined Disease Risk Index (rDRI) is a prognostic tool used in hematopoietic cell transplant (HCT), solely based on disease type and status. Its value in patients undergoing UCB transplants (UCBT) with different conditioning regime intensity is unclear. We sought to evaluate the predictive value of rDRI in patients undergoing UCBT. Methods: We performed a retrospective analysis of 107 adult patients with various hematological malignancies who underwent 4-6/6 HLA-matched UCBT using single unit UCB (n=14) or double unit UCB (n=93) between Aug 2006 and Nov 2019 at 2 academic tertiary hospitals in Singapore. Patients received pre-transplant conditioning with either myeloablative conditioning (MAC, n=63) regimen consisting of Fludarabine (Flu) 75mg/m2, Cyclophosphamide (Cy) 120mg/kg and total body irradiation (TBI) 12- 13.2Gy , intensified reduced intensity conditioning (i-RIC, N=22) regimen consisting of Flu 150 mg/m2, Cy 50mg/kg, thiotepa 10mg/kg and TBI 4 Gy, or nonmyeloablative conditioning (NM, n=22) regimen, consisting of Flu 200 mg/m2, Cy 50mg/kg and TBI 2 Gy. The median total nucleated cell dose infused was 5.07 x 107/kg (range, 2.61 to 11.5) Results: Median follow-up was 84 months (range, 6 to 167 months).. Kaplan-Meier estimates of overall (OS) and event-free (EFS) survival at 10 years were 40 % (95% CI, 31-50) and 37% (95% CI, 28-47) respectively. At 2 years, cumulative incidence (CI) of relapse-related mortality (RRM) and non-relapse mortality (NRM) were 27% (95% CI, 18-35) and 35 % (95% CI, 25-45), respectively. In multivariate analysis (MVA), rDRI showed significant correlation with OS (HR 2.41; 95% CI 1.41-4.11; p=0.001), EFS (HR 2.54; 95% CI 1.51-4.28; p=0.0004) and RRM (HR 2.71; 95% 1.36-5.41; p=0.005). Conditioning regimen intensity was found to have significant impact on NRM (p=0.047) and RRM (p=0.002) in MVA. When patients were further stratified into 4 risk groups incorporating both rDRI and conditioning regimen intensity, significant differences in OS (p=0.002) and EFS (p=0.001) were seen. 5-year OS (Figure 1) in patients receiving MAC/i-RIC and NM conditioning with low-intermediate risk rDRI were 52% and 36% respectively, compared with 24% and 13% in patients with high-very high risk rDRI (p=0.002). The corresponding ES were 50%, 29%, 20%, and 13%, respectively (Figure2). Conclusions: Our results confirm that rDRI has good predictive value for relapse and survival in UCBT recipients. Conditioning regime intensity was also found to have a significant impact on patient outcomes when evaluated together with rDRI. Prognostic scoring systems in HSCT are revised constantly with further studies needed to potentially incorporate the intensity of the conditioning regime into the rDRI. Outcomes in rDRI high risk patients remain poor and further studies are needed to define the best strategy that can induce sustained engraftment without increasing risk of relapse and toxicity death. Disclosures No relevant conflicts of interest to declare.

Research Advances on Clinical Application of Umbilical Cord Blood Transplantation in the Treatment of Hematological Diseases--Review

Abstract Umbilical cord blood (UCB) is an alternative source of hematopoietic stem cells (HSCs) for patients who were lack of HLA match related or unrelated donors. Compared with bone marrow and mobilized peripheral blood, UCB has the advantages of easy availability, safety for donors, and low requirement for HLA match between donors and recipients. However, the cell amount in UCB is relatively less, which was associated with increased graft failure, delayed hematologic recovery, immune reconstitution, and higher transplant related mortality after UCB transplantation (UCBT). Double-unit UCB is a straightforward method to augment cell amount in UCB. Compared with single-unit UCBT, double-unit CBT associated with less risk of primary disease relapse and increased incidence rate of graft-versus-host disease (GVHD), but the hematologic recovery and overall survival of recipients were no significantly difference between single and double-unit UCBT. Novel strategies for UCB expansion significantly increased the cell amount in UCB, single-unit expanded UCBT not only increased the sources of UCB, but also decreased the high cost of double-unit UCB. ATG can decrease the risk of graft failure and GVHD rate, but the role of ATG in UCBT is still controversial. Herein, the recent clinical advances on UCBT in the treatment of hematologic diseases are systematically reviewed.

Single- Versus Double-Unit Umbilical Cord Blood Transplantation for Hematologic Diseases: A Systematic Review.

Controversial results exist regarding the clinical benefits of single- vs double-unit umbilical cord blood transplantation (UCBT) in patients with hematologic diseases. A systematic review was conducted to evaluate this issue. The PubMed, Embase, and Cochrane Library databases were searched up to May 2018. A total of 25 studies including 6571 recipients were identified. Although double-unit UCB contained higher doses of total nucleated cells and CD34+ cells, it offered no advantages over single-unit UCB in terms of hematologic recovery, including the rate and speed of neutrophil and platelet engraftment. Double-unit UCBT was associated with higher incidences of grades II-IV acute and extensive chronic graft-vs-host disease, accompanied by a lower relapse incidence, which may be attributed to a graft-vs-graft effect induced by double-unit UCB. However, transplant-related mortality, disease-free survival, and overall survival were comparable between single- and double-unit UCBT. Although double-unit UCBT confers no clinical advantages over single-unit UCBT, certain patients, such as those at high risk of relapse, might benefit from double-unit UCBT, a possibility that needs to be clarified in future randomized trials.

Single-Unit versus Double-Unit Umbilical Cord Blood Transplantation in Children and Young Adults with Residual Leukemic Disease

We previously reported in a French prospective randomized study that transplantation of 2 unrelated cord blood (UCB) units instead of 1 unit does not decrease the risk of transplantation failure but may enhance alloreactivity. Here we evaluated the influence of pretransplantation minimal residual disease (MRD) on leukemia relapse and survival after single- versus double-UCB transplantation (UCBT). Among 137 children and young adults who underwent UCBT in this randomized study, 115 had available data on MRD assessment done immediately before initiation of the pretransplantation conditioning regimen. MRD was considered positive at a level of ≥10-4, which was the case of 43 out of 115 patients. Overall, the mean 3-year survival probability was 69.1 ± 4.4%, and it was not significantly influenced by the MRD level: 70.7 ± 5.4% in MRD-negative (<10-4) patients (n = 72), 71.1 ± 9.4% in MRD-positive patients with 10-4 ≤ MRD <10-3 (n = 26) and 58.8 ± 11.9% in MRD-positive patients with ≥10-3 (n = 17). In the MRD-positive group, the mean risk of relapse was significantly lower in the double-UCBT arm compared with the single-UCBT arm (10.5 ± 7.2% versus 41.7 ± 10.4%; P = .025) leading to a higher mean 3-year survival rate (82.6 ± 9.3% versus 53.6 ± 10.3%; P = .031). This difference was observed only in patients who had not received antithymocyte globulin during their conditioning regimen. In the MRD-negative group, there was no differencebetween the single- and the double-UCBT arms. We conclude that even in cases of positive pretransplantation MRD, UCBT in children and young adults with acute leukemia yields a high cure rate, and that a double-unit strategy may enhance the graft-versus-leukemia effect and survival in these patients.

Cord Blood Unit Dominance Analysis and Effect of the Winning Unit on Outcomes after Double-Unit Umbilical Cord Blood Transplantation in Adults with Acute Leukemia: A Retrospective Study on Behalf of Eurocord, the Cord Blood Committee of Cellular Therapy, Immunobiology Working Party, and the Acute Leukemia Working Party of the European Group for Blood and Marrow Transplantation

Usually, after double umbilical cord blood transplantation (DUCBT), only 1 of the transplanted units persists in the long term. The characteristics of the winning cord blood unit (W-CBU) that determine unit dominance and how they influence the outcomes of DUCBT remain unclear. We retrospectively analyzed 347 patients with acute leukemia transplanted with a DUCBT (694 CBU) from 2005 to 2013 who had documented neutrophil engraftment and a W-CBU identified by chimerism analysis, to identify unit characteristics impacting on dominance. Median age at DUCBT was 40 years and median follow-up was 35 months. Among W-CBUs, 41% were ≥5/6 HLA matched to the recipient and 59% were ≤4/6. Multivariate analysis indicated that ≤4/6 HLA-matched W-CBUs led to lower leukemia-free survival (44% versus 56%; hazard ratio [HR], 1.5; P = .032) and overall survival (49% versus 62%; HR, 1.5; P = .028), increased nonrelapse mortality (26% versus 18%; HR, 1.9; P = .027), and acute graft-versus-host disease (46% versus 35%; HR, 1.7; P = .013). We were unable to predict unit dominance, but we demonstrated that outcomes were strongly influenced by the degree of HLA mismatch between W-CBU and recipient. Therefore, selection of both units with the lower number of HLA mismatches with the recipient is indicated.

Angiogenic Factors Correlate with T Cell Immune Reconstitution and Clinical Outcomes after Double-Unit Umbilical Cord Blood Transplantation in Adults

Umbilical cord blood (UCB) is a valuable graft source for allogeneic hematopoietic stem cell transplantation (HSCT) in patients who lack adult donors. UCB transplantation (UCBT) in adults results in delayed immune reconstitution, leading to high infection-related morbidity and mortality. Angiogenic factors and markers of endothelial dysfunction have biologic and prognostic significance in conventional HSCT, but their role in UCBT has not been investigated. Furthermore, the interplay between angiogenesis and immune reconstitution has not been studied. Here we examined whether angiogenic cytokines, angiopoietin-1 (ANG-1) and vascular endothelial growth factor (VEGF), or markers of endothelial injury, thrombomodulin (TM) and angiopoietin-2 (ANG-2), associate with thymic regeneration as determined by T cell receptor excision circle (TREC) values and recovery of T cell subsets, as well as clinical outcomes in adult recipients of UCBT. We found that plasma levels of ANG-1 significantly correlated with the reconstitution of naive CD4+CD45RA+ and CD8+CD45RA+ T cell subsets, whereas plasma levels of VEGF displayed a positive correlation with CD4+CD45RO+ T cells and regulatory T cells and a weak correlation with TRECs. Assessment of TM and ANG-2 revealed a strong inverse correlation of both factors with naive T cells and TRECs. The angiogenic capacity of each patient's plasma, as determined by an in vitro angiogenesis assay, positively correlated with VEGF levels and with reconstitution of CD4+ T cell subsets. Higher VEGF levels were associated with worse progression-free survival and higher risk of relapse, whereas higher levels of TM were associated with chronic graft-versus-host disease and nonrelapse mortality. Thus, angiogenic factors may serve as valuable markers associated with T cell reconstitution and clinical outcomes after UCBT.

Final Results of the First-in-Human Clinical Study Incorporating Hyperbaric Oxygen into Umbilical Cord Blood Transplantation

Background: Umbilical cord blood (UCB) transplantation is associated with delayed blood count recovery and engraftment. We have demonstrated that pre-treatment with hyperbaric oxygen (HBO) therapy to the recipient mice improved engraftment of intravenously infused human UCB CD34+ in a murine transplant model. Further studies from our laboratory attribute HBO effects on engraftment to HBO-induced low erythropoietin (EPO) state in the host, resulting in early UCB CD34+ cell bone marrow homing and an increase in myeloid to erythroid differentiation. These results lead to the first in-human pilot clinical trial investigating the safety of HBO in the setting of UCB transplantation and secondarily evaluating time to blood count recovery. Herein, we report the final results of this study in comparison to our historic institutional data to determine the impact of HBO on blood count recovery and day +100 survival.Materials/methods: Enrolled patients had hematologic malignancies that required reduced intensity conditioning (RIC) or myeloablative conditioning (MAC) and UCB transplantation. They received HBO therapy on day 0 consisting of exposure to 2.5 atmosphere absolutes for a total of 2 hours, in a single hyperbaric chamber, breathing 100% oxygen. Six hours from the start of HBO, single or double UCB units were intravenously infused and patients were followed daily for toxicity and blood count recovery. Serum EPO levels were measured by enzyme-linked immunosorbent assay (ELISA). Mycophenolate mofetil and cyclosporine were used for GVHD prophylaxis. Charts of 48 patients who received UCB transplantation at our institution for hematologic malignancies between 2008 and 2013 were reviewed for comparison.Results: 15 patients, 9 males (60%) and 6 females (40%), with a median age of 44 years (17-70) were treated. One patient had lymphoma and 14 patients had acute leukemia; 10 in first remission and 4 in second remission. Eight patients received one UCB unit and 7 received two units. Patients received a median total nucleated cell dose of 3.02(1.67-4.51) ×107/Kg recipient body weight (BWT), a median CD34 cell dose of 1.2 (0.7-6.5) ×105/Kg recipient BWT, and 9/15 patients received RIC. 14/15 treated patients completed the planned therapy, while one patient did not finish the last 15 minutes due to nausea. None of the patients experienced an unexpected toxicity. All patients engrafted except for one patient who demonstrated prompt autologous blood count recovery. Full donor chimerism was achieved in 7/8 (88%) of engrafted RIC patients 30 days post-transplant. Eleven of the 15 (67%) patients developed acute graft versus host disease at time of engraftment; 36% developed grade I, 54% had grade II and 9% had grade III. On average, EPO levels 8-hours post HBO were 56 (27-92) % of their pre-HBO values. Median time to neutrophil count recovery, median time to platelet count recovery, day +100 survival (Figure-1), percentage of patients who achieved neutrophil recovery and platelet count recovery in the HBO and historic cohorts are summarized in table-1.Conclusions: HBO therapy prior to UCB cell infusion appears to be safe and well-tolerated in the setting of clinical UCB transplantation. Given the potential benefits of relatively fast recovery and lack of toxicity, HBO should be further evaluated as a strategy to promote engraftment in UCB transplantation.Table 1Summary of transplant outcomes in HBO and historic cohorts.AllMACRICHBO (n=15)Historic (n=48)P valueHBO (n=6)Historic (n=21)P valueHBO (n=9)Historic (n=27)P valueDay 100 survival (n/%)No- (0%)11 (24%)0.051- (0%)10 (48%)0.03- (0%)1 (4%)NSYes15 (100%)34 (76%)6 (100%)11 (52%)9 (100%)23 (96%)Neutrophil recovery (n/%)No- (0%)6 (12%)NS- (0%)4 (19%)NS- (0%)2 (7%)NSYes15 (100%)42 (88%)6 (100%)17 (81%)9 (100%)25 (93%)Platelet recovery (n/%)No- (0%)15 (31%)0.013- (0%)11 (52%)0.023- (0%)4 (15%)NSYes15 (100%)33 (69%)6 (100%)10 (48%)9 (100%)23 (85%)Median time to neutrophil recovery (Range)14 (6-45)20.5 (5-71)NS24.5 (16-45)33 (13-71)NS7 (6-17)14 (5-28)NSMedian time to platelet recovery (Range)37.5 (0-85)38 (0-161)NS54.5 (30-84)50 (29-161)NS32 (0-85)38 (0-112)NS [Display omitted] DisclosuresNo relevant conflicts of interest to declare.

Pilot Clinical Study Incorporating Hyperbaric Oxygen into Umbilical Cord Blood Transplantation

▪Background: Umbilical cord blood (UCB) is a rich source of hematopoietic stem cells and may be the only allogeneic transplant option for some patients with hematologic malignancies. However, UCB transplantation is associated with delayed blood count recovery and engraftment. In preclinical studies, we have demonstrated that hyperbaric oxygen (HBO) therapy, given prior to cytokine expanded and gene-transduced UCB CD34+ cell infusion, improves peripheral blood, bone marrow, and spleen engraftment in a murine model. Based on these results, we started a pilot clinical trial primarily investigating the safety of HBO in the setting of UCB transplantation. Secondarily, we are evaluating the time to neutrophil and platelet count recovery and engraftment.As a potential marker for effective HBO therapy, we also evaluated serum erythropoietin (EPO) levels in transplanted patients prior to HBO therapy and again at time of transplantation.Materials/methods: Patients with hematological malignancies that require UCB transplantation, either reduced intensity or myeloablative, were included. On day 0, patients received HBO treatment consisting of exposure to 2.5 atmosphere absolutes for a total of 2 hours, in a single hyperbaric chamber, breathing 100% oxygen. Six hours from the start of HBO, single or double UCB units were infused and patients were followed daily for toxicity and blood count recovery. Serum EPO levels were measured by enzyme-linked immunosorbent assay (ELISA).Results: 18 patients were screened for this study, 9 were enrolled, and 9 were treated. The treated subjects were 5 males (56%) and 4 females (44%) with median age of 44 (23-70) who had acute myeloid leukemia (n=6), non-Hodgkin’s lymphoma (n=1), and acute lymphoblastic leukemia (n=2); all patients were in first (n=8) or second (n=1) complete remission. All but two patients received one UCB unit with a median total nucleated cell dose of 3.3 (2.7-4.5) ×107 /Kg recipient body weight and 6 of 9 patients received reduced intensity conditioning. All treated patients completed the planned therapy without a treatment limiting toxicity defined as the occurrence of any of the following complications within 24 hours of HBO: seizure disorder, pneumothorax, death or irreversible grade III or any grade IV toxicity that is determined by the treating physician to be, at least, likely related to HBO therapy. None of the patients experienced an unexpected toxicity. All patients engrafted except for one patient who demonstrated prompt autologous blood count recovery. Platelet count recovery was not assessable in one patient. Time to neutrophil count recovery (defined as the first of 3 consecutive days of an absolute neutrophil count (ANC) of greater than 500/μL) and time to platelet count recovery (defined as the first day of a sustained platelet count greater than 20 K/UL) were 16 (6-25) and 32 (8-87), respectively. 90% or higher donor chimerism was documented in peripheral blood/bone marrow of engrafted patients receiving reduced intensity regimen at a median of 18 (15-31) days post-transplant. Six of the 9 (67%) patients developed acute graft versus host disease at time of engraftment; 50% developed grade I, 33% had grade II and 17% had grade III. In 7 patients who had serum EPO levels assessed, median EPO levels at time of UCB infusion were lower than their median levels prior to HBO therapy (11.3 vs. 25.2 mU/mL).Conclusions: HBO therapy prior to UCB cell infusion appears to be well-tolerated in the setting of clinical umbilical cord blood transplantation. Time to neutrophil recovery/engraftment as well as platelet count recovery appear to be encouraging. HBO therapy resulted in lower EPO serum levels at time of UCB infusion. DisclosuresNo relevant conflicts of interest to declare.

Second Allogeneic Stem Cell Transplantation for Hematologic Malignancies Using Chemotherapy Only Cytoreduction with Clofarabine, Melphalan, and Thiotepa

Background:Allogeneic hematopoietic stem cell transplantation (alloHSCT) plays an important role in the treatment of patients with high-risk hematologic malignancies. However, relapse of disease remains the primary cause of mortality post HSCT. Treatment options for these patients remain limited, and outcomes after salvage attempts are often poor, due to both increased toxicity and high rates of relapse. We describe a chemotherapy-only cytoreductive regimen consisting of clofarabine (Clo), melphalan (Mel) and Thiotepa (Thio) for the treatment of patients undergoing a second or third HSCT (HSCT2 or HSCT3).Methods: Between November 2005 and December 2012, 19 patients with hematologic malignancies who had relapsed after prior alloHSCT received a HSCT2 (N=17) or HSCT3 (N=2) using this regimen. There were 12 males and 7 females aged 4.5-44 years (median 20.2 years). Diagnoses and stages at the time of HSCT2/3 included: ALL in second complete remission (CR2; N=4) or CR3 (N=8); AML in CR2 (N=2) or CR3 (N=4); and CML in 2nd chronic phase (N=1). Seven patients had extramedullary disease, including CNS (N=5), testicle (N=1), and bone (N=1). Time to relapse following prior HSCT was 0-6 months (N=6), 6-12 months (N=7), or >12 months (N=6). Median time between most recent and present HSCT was 15 months (range 8.5 – 225 months). Thirteen patients received allografts from the same donor used for prior alloHSCT, while 6 pts received allografts from different donors. Grafts comprised conventional/unmodified marrow (cBMT) (N=7), peripheral blood (cPBSCT) (N=6), double umbilical cord blood units (N=1), or T-cell depleted (TCD) PBSCT (N=5). Cytoreduction included Clo 20 (N=18) or 30 (N=1) mg/m2/dose x 5, Thio 10 mg/m2 x 1, and Mel 70 mg/m2/dose x 2. GvHD prophylaxis included tacrolimus + methotrexate or mycophenolate for the unmodified grafts, while recipients of TCD grafts received ATG only pre-transplant for rejection prophylaxis. TCD was achieved by CD34+ selection, with the addition of E-rosetting in one case. All patients received filgrastim from day +7 until neutrophil engraftment.Results: Neutrophil engraftment occurred in all patients at a median of 12 days (range 9-25). Platelet recovery occurred in 17 evaluable patients at a median of 22 days (range 14-98). Transplant related mortality was limited to 2 patients, one who died of veno-occlusive disease 27 days post-transplant and the other of EBV lymphoma 11 weeks post-transplant. Neither of these patients recovered their platelet counts. Regimen related toxicity included: grade 3-4 mucositis (N=5), grade 4 renal toxicity (N=2), grade 3-4 hypoxia (N=3). Fifteen patients developed grade 3-4 transaminitis beginning immediately following clofarabine administration, which completely resolved in 14/15 cases. Five patients, all recipients of unmodified grafts, developed grade 2-4 acute GvHD, two of whom developed chronic GvHD; one patient who received a cPBSCT developed de novo chronic GvHD.Seven patients relapsed at a median of 14.6 months (range: 3.5-25.3 months) post-HSCT2/3, and all died of their disease. Ten of 19 patients are alive and disease free with median follow-up of 50.1 months (range 22.8-90.4). Overall and disease-free survival probabilities were 51.5% and 52.6% respectively. There were no statistically significant difference in OS or DFS for the following factors: (1) patient age < or ≥ 21 years, (2) grafts from same or different donor, (3) myeloid vs. lymphoid disease, (4) CR2 vs. CR3 at HSCT, (5) TCD vs. unmodified grafts. Outcome was significantly superior for patients whose relapse occurred > 6 months from prior HSCT, with an OS of 75.2% compared with 0% (p<0.0001) in patients whose relapse was ≤ 6 months. Of the 6 patients who received HSCT2/3 for relapse within 6 months of their first HSCT, 4 died from relapse, and 2 died from transplant related mortality.Conclusions: This cytoreductive regimen has allowed secondary transplants in a cohort of high-risk patients with ALL and AML who relapsed following a prior transplant using various graft and donor options. Overall, the regimen is well tolerated and has yielded promising results, specifically in patients who relapse more than 6 months from their prior transplant. This salvage treatment merits further study and evaluation in collaborative group studies. DisclosuresOff Label Use: Clofarabine, melphalan, and thiotepa all off label for bone marrow transplant.. Boulad:Genzyme Sanofi: Trials partially funded by Genzyme Sanofi Other.

Prognostic Value of TREC, IL-7 and SCF Levels on Clinical Outcomes after Double Umbilical Cord Blood Transplantation in Adults

Umbilical cord blood (UCB) is an alternative source of hematopoietic stem cells (HSC) for allogeneic HSC transplantation but reconstitution of T cell immunity remains problematic even with double unit UCB transplantation (dUCBT). We previously reported that reconstitution of thymopoiesis plays a critical role in the clearance of CMV viremia, and is associated with improved overall survival in dUCBT recipients. Furthermore, we determined that T cell subset recovery after dUCBT depends on the production of IL-7 and SCF. In the present study we investigated whether thymic reconstitution after dUCBT depends on IL-7 and SCF and examined the prognostic role of T-cell receptor excision circles (TRECs), IL-7 and SCF on clinical outcomes after dUCBT. We analyzed 52 adult patients with hematologic malignancies who enrolled in parallel Phase I/II clinical trials of dUCBT at the Dana-Farber/Harvard Cancer Center. Forty three patients received reduced intensity conditioning with fludarabine, melphalan and antithymocyte globulin; nine patients received myeloablative conditioning with fludarabine, cyclophosphamide and TBI. Thirteen of these patients received human PTH and 13 patients received one untreated and one ex-vivo PGE2 treated UCB unit, per study protocols. GvHD prophylaxis was tacrolimus in combination with sirolimus or mycophenolate mofetil. Assessments were performed at baseline (before conditioning) and at 1, 2, 3, 6 and 12 months after dUCBT. The median follow-up time among survivors was 71 months (range 24-96). The incidence of grade II-IV aGvHD was 15.4% and 14 out of 48 patients (29%) alive after 3 months developed cGvHD. The cumulative incidence of relapse at 5 years was 43%. The 5-year non-relapse mortality (NRM), progression-free survival (PFS) and overall survival (OS) were 31%, 26%, and 41% respectively. Plasma levels of IL-7 increased 3-fold from baseline at 1 month after dUCBT (median 26.4 pg/mL), remained elevated during the first three months, and gradually declined to pre-transplant levels by 1 year. SCF increased more slowly reaching peak levels at 2 months after dUCBT (median 1335.7 pg/mL), and gradually decreased thereafter. All but one evaluable patient had detectable TRECs at baseline with a median value of 3304 copies/ug DNA. TRECs were absent or extremely low during the first 3 months after dUCBT. At 6 months, 69.7% of patients had detectable TRECs, albeit below normal range (median value of 248 copies/ug DNA), but at 12 months 86.6% of the patients had detectable levels with a normal median value of 2404 copies/ug. We observed a statistically significant inverse correlation between IL-7 and TREC levels at 2 months after UCBT (r=-0.48, p=0.036). Similarly, SCF inversely correlated with TRECs at 6 months (r=-0.5, p=.004) and 12 months after dUCBT (r=-0.48, p=.02). We hypothesize that this inverse correlation is likely due to the uptake of IL-7 and SCF by thymocytes leading to their differentiation into TREC-containing Recent Thymic Emigrants (RTE). In support of this hypothesis, IL-7 and SCF inversely correlated with naïve CD4CD45RA+ T cells at various time points after dUCBT. Next, we examined whether TREC, IL-7 and SCF levels might have a prognostic value for clinical outcomes after UCBT. In multivariable models, higher TREC levels were found to be independently associated with improved progression-free survival (PFS) (p=0.02) and overall survival (OS) (p=0.02), and with less non-relapse mortality (NRM) (p=0.002). In contrast, higher levels of IL-7 and SCF were associated with lower OS (p=0.005 and p&lt;.0001 respectively) and a trend towards lower PFS. Furthermore, higher levels of IL-7 and SCF were adverse prognostic factors for NRM (p=0.07 and p=0.007) but not for relapse. Taken together, our findings suggest that adult dUCBT recipients develop thymic reconstitution as early as 6 months after transplantation and TREC values correlate with improved clinical outcomes of dUCBT. In contrast, higher levels of IL-7 and SCF are associated with poor quantitative T cell and thymic reconstitution and they are negative prognostic factors for OS and NRM, which mainly reflects mortality due to infections and GvHD. These findings emphasize the link between cytokine-mediated immune reconstitution of post-thymic T cells and clinical outcomes of transplantation in adult dUCBT recipients. Disclosures No relevant conflicts of interest to declare.

KIR and HLA genotypes have no identifiable role in single-unit dominance following double-unit umbilical cord blood transplantation.

KIR and HLA genotypes have no identifiable role in single-unit dominance following double-unit umbilical cord blood transplantation

Outcomes of Double Unit Umbilical Cord Blood Transplantation Using Fludarabine/Busulfan Based Reduced Intensity Conditioning Regimen

Outcomes of Double Unit Umbilical Cord Blood Transplantation Using Fludarabine/Busulfan Based Reduced Intensity Conditioning Regimen

Double Unit Umbilical Cord Blood Transplant for Adults with Acute Leukemia and Myelodysplastic Syndrome Results in Comparable Outcome As Matched Sibling or Unrelated Donor Transplant Only after Myeloablative Conditioning but Not Reduced Intensity Conditio

Double Unit Umbilical Cord Blood Transplant for Adults with Acute Leukemia and Myelodysplastic Syndrome Results in Comparable Outcome As Matched Sibling or Unrelated Donor Transplant Only after Myeloablative Conditioning but Not Reduced Intensity Conditio