Single Umbilical Cord Blood Transplantation Research Articles

Immune reconstitution after single-unit umbilical cord blood transplantation using anti-thymoglobulin and myeloablative conditioning in adults with hematological malignancies.

This study aimed to investigate the kinetics of immune recovery following umbilical cord blood transplantation (UCBT) in adults who received a myeloablative conditioning (MAC) regimen and antithymocyte globulin (ATG). While the immune recovery kinetics has been extensively studied in pediatric UCBT recipients, limited data exist for adults. We conducted a comprehensive analysis of 221 consecutive adult patients who underwent UCBT with MAC and ATG at a single institution. Our objective was to evaluate the influence of patient, disease, and transplant factors, along with acute graft-versus-host disease (aGVHD), on immune reconstitution and overall survival. Our findings confirm a delayed recovery of T cells, while B and NK cell reconstitution exhibited rapid progress, with NK cell counts reaching normal levels within 3 months post-transplantation and B cells within 6 months. Within CD3+ T cells, CD8+ T cells also experienced a delayed recovery (12 months), but to a lesser extent compared to CD4+ T cells (18 months). Delayed immune recovery of T-cell subsets was associated with the development of aGVHD grade II-IV, older age, CMV negativity, and a female donor. Patients with lymphoproliferative diseases showed slower NK cell recovery. Our study demonstrates that adult patients undergoing MAC with ATG and receiving a single unit UCBT for hematologic malignancies experienced rapid reconstitution of NK and B cells. However, T cell recovery, particularly CD4+ T cells, was significantly delayed. To enhance T cell recovery, it may be crucial to consider UCB units with higher cellularity and optimize ATG doses in conditioning.

Comparison of long-term outcomes after first HLA-mismatched unrelated donor transplantation with single unrelated cord blood transplantation using reduced-intensity or reduced-toxicity conditioning

BackgroundNo comparative data have shown significant survival differences between HLA-mismatched unrelated donor (MMUD) transplantation and cord blood (CB) transplantation, each with reduced-intensity/reduced-toxicity conditioning (RIC/RTC). However, advances in graft-versus-host disease (GVHD) prophylaxis might help update current strategies. MethodsWe retrospectively compared the outcomes of first allogeneic hematopoietic cell transplantation from MMUDs (n = 15) or single unrelated CB (n = 35) after RIC/RTC. ResultsThe median age was 60 years. The MMUD group had a numerically lower 100-day incidence of grade III–IV acute GVHD (7% vs. 29%, P = 0.079) and non-relapse mortality (0% vs. 40%, P = 0.12). Eight MMUD recipients received anti-thymocyte globulin, bortezomib, or posttransplant cyclophosphamide for GVHD prophylaxis. They did not develop grade III–IV acute GVHD. The MMUD group had significantly better 5-year overall survival than the CB group (62% vs. 31%, P = 0.021), although relapse rates were similar. A multivariable analysis and sensitivity analysis also showed trends toward higher overall survival in the MMUD group. ConclusionMMUD with better GVHD prophylaxis might be preferred over CB in patients with older age and comorbidities.

Comparison of Non-Relapse Mortality after Haploidentical Hematopoietic Stem Cell Transplantation with Post-Transplant Cyclophosphamide Versus Single Umbilical Cord Blood Transplantation for Hematologic Disease

Introduction: Unrelated cord blood transplantation (UCBT) and haploidentical stem cell transplantation with post-transplant cyclophosphamide as graft-versus-host disease (GVHD) prophylaxis (PTCy-haplo) are alternative options for patients with hematologic disease lacking a human leukocyte antigen (HLA)-matched donor. Non-relapse mortality (NRM) after UCBT may vary depending on the cord blood CD34+ cell count, but no study has accounted for CD34+ cell count when comparing the outcomes after UCBT and PTCy-haplo. Therefore, we analyzed transplant outcomes after UCBT and PTCy-haplo in patients with hematologic disease from data of a nationwide registry that included cord blood CD34+ cell count. Methods: Patients with hematologic disease receiving first UCBT or PTCy-haplo between 2014 and 2020 were identified from the nationwide registration data of the Japanese Data for Hematopoietic Cell Transplantation. Acute GVHD-related mortality was defined as death caused primarily by GVHD or occurred secondary to GVHD, and infection-related mortality as death due to graft failure or infection but not acute GVHD. Patients treated by UCBT were stratified by the median CD34+ cell count for comparison (0.84 × 10 5/kg). Results: A total of 7,499 patients were enrolled and classified into 3 groups: PTCy-haplo (n = 1,142), UCBT with high CD34+ cell count (UCB-H; ≥ 0.84 × 10 5/kg, n = 3,185), and UCBT with low CD34+ cell count (UCB-L; < 0.84 × 10 5/kg, n = 3,172). Patients in the PTCy-haplo group were slightly younger than UCB-H and UCB-L patients (median age: 54 vs. 56 and 55 years). The PTCy-haplo group also included a greater proportion of males than the UCB-H group (62.4% vs. 50.0%) but not the UCB-L group (64.2%). A greater proportion of PTCy-haplo patients had a PS score of 0 (53.2% vs. 46.2% and 45.6%), a hematopoietic cell transplantation-specific comorbidity index of 0 (57.6% vs. 52.7% and 54.4%) and donor-specific anti-HLA antibody (2.7% vs. 1.0% and 1.6%), received reduced-intensity conditioning (58.0% vs. 40.5% and 41.6%), calcineurin inhibitor with mycophenolate mofetil (88.5% vs. 38.6% and 38.4%), and underwent transplantation in the later period (82.0% vs. 54.6% and 50.7%). There were no significant differences in disease-risk index between groups. At 2 years post-transplantation, NRM and overall survival (OS) were significantly better in the PTCy-haplo group than the UCB-H and UCB-L groups (NRM: 18.8% vs. 21.6% and 25.3%, P < 0.001; OS: 56.2% vs. 53.3% vs. 49.6%, P < 0.001). Neutrophil engraftment rate at 42 days was also significantly higher in the PTCy-haplo group than the UCB-H and UCB-L groups (93.7% vs. 87.5% and 82.9%, P < 0.001). The PTCy-haplo group less frequently developed grade II-IV (26.4% vs. 37.3% and 34.4%, P < 0.001) and III-IV acute GVHD (7.0% vs. 12.2% and 10.5%, P < 0.001). While neither the differences in NRM nor that in OS remained significant between PTCy-haplo and UCB-H groups in multivariable analysis (NRM: hazard ratio [HR], 1.18, 95% confidence interval [CI], 0.99-1.41, P = 0.073; OS: HR, 1.05, 95% CI, 0.94-1.17, P = 0.42), significant differences were maintained between PTCy-haplo and UCB-L groups (NRM: HR, 1.35, 95% CI, 1.13-1.61, P = 0.001; OS: HR, 1.12, 95% CI, 1.00-1.26, P = 0.042). Regarding the cause-specific mortality, infection-related mortality was also significantly lower in the PTCy-haplo group compared to UCB-H and UCB-L groups (8.1% vs. 11.1% and 13.6%, P < 0.001) while GVHD-related mortality did not differ among groups (5.0% vs. 5.2% and 4.9%, P = 0.69). Conclusion: UCBT-H resulted in similar NRM and OS as patients receiving PTCy-haplo, whereas outcomes were worse in UCBT-L. These findings indicate that high CD34+ cell count in cord blood is a critical criterion for alternative donor selection.

Impact of Allele-Level HLA-Matching on Outcomes after Double Cord Blood Transplantation in Adults with Malignancies.

In single unrelated cord blood transplantation (UCBT), an increasing number of HLA allele mismatches (MM) has been associated with inferior overall survival (OS) attributed to higher transplant-related mortali-ty (TRM). Previous studies on the role of allele-level HLA matching following double UCBT (dUCBT) showed conflicting results. Herein we report the impact of allele-level HLA matching on outcomes of a large dUCBT cohort . We included 963 adults with hematologic malignancies, with available allele-level HLA matching at HLA-A, -B, -C and -DRB1, receiving dUCBT between 2006-2019. Assignment of donor-recipient HLA match was performed considering the unit with the highest disparity with the recipient. 392 patients received dUCBT with 0-3 and 571 with ≥4 allele MM. Day-100 and 4-year TRM were 10% and 23%, for recipients of dUCBT with 0-3 MM compared to 16% and 36% for those with ≥4 MM (HR 1.58, p=.002; and HR 1.54, p=.002), respectively. Higher degree of allele MM was also associated with worse neutrophil recovery and lower incidence of relapse; no significant effect on graft-versus-host disease was observed. Patients receiving units with 0-3 MM had a 4-year OS of 54% versus 43% for those with ≥4 MM (HR 1.40, p=.005). The inferior OS associated with higher HLA disparity was only partially mitigated by increased total nucleated cell doses. Our results confirm that allele-level HLA typing is a significant factor for OS following dUCBT and units with ≥4 MM (≤4/8 HLA-matched) should be avoided if possible.

Impact of Allele-Level HLA-Matching on Outcomes after Double Unrelated Cord Blood Transplantation in Adults with Malignant Diseases

Introduction: In single unrelated cord blood transplantation (sCBT), an increasing number of HLA-mismatches (MM) has been associated with inferior overall survival (OS) attributed to higher transplant-related mortality (TRM). These findings have prompted current guidelines to endorse high resolution HLA typing in the selection of CB (cord blood) units, including double CBT (dCBT). However, a comprehensive appraisal of the effect of allele-level HLA matching following dCBT was likely hindered by the relatively small sample sizes in previous studies. Herein we aimed to analyze the impact of allele-level HLA-matching on outcomes of a large cohort of dCBT recipients to improve CB unit selection and further explore the unique dCBT biology. Methods: We included patients ≥18 years-old receiving a dCBT between 2006-2019 with the availability of HLA typing minimally at HLA-A, -B, -C at the antigen-level and HLA-DRB1 at the allele-level for the recipient and both CB units. A validated high-resolution imputation tool, HaploStats, was used to adjudicate allele-level match status for a subset of cord and recipient pairs (n = 173) having only antigen-level typing at HLA-A, -B or -C. A sensitivity analysis for OS was performed excluding imputed cases, and results were unchanged. HLA matching was classified according to the CB unit with the greatest degree of HLA mismatch with the patient, meaning that only the most mismatched unit was considered and that the interunit matching was not considered. Continuous covariates were dichotomized to find an optimal cutoff value by using the Contal-O'Quigley method, except for cryopreserved CD34 and total nucleated cell (TNC) count, whose cutoffs were based on previous findings reported by our group. Pairwise comparisons of the numbers of allele MM showed that receiving units with ≥4 MM had the highest negative impact on OS. Cox and Fine-Gray regression models were built for the different outcomes using the backward elimination method (p<.05 to stay). Results: 963 patients met the eligibility criteria, of which 392 received at least one CB unit with 0-3 allele MM while 571 with ≥4 allele MM. Of those receiving at least one unit with ≥4 allele MM, 18% had a maximum HLA disparity of 5/6 at lower HLA-typing resolution, 69% of 4/6 and 13% of ≤3/6. Median age at dCBT was 49 years old. Acute leukemia and myelodysplastic syndrome (MDS) accounted for 70% of the cases. There was a larger proportion of patients receiving CB units with fewer allele MM after 2012. Other patient-, disease- and CB unit-related characteristics are summarized in Table 1. The day-42 cumulative incidence of neutrophil recovery was 83% (95%CI 81-85). The number of allele MM had no significant impact on neutrophil recovery (≥ 4 MM vs 0-3 MM, multivariate HR 0.94 [0.80-1.11], P=.46). The cumulative incidence of TRM at 4 years was 36% (95% CI 32-40) for patients receiving CB units with ≥4 MM vs. 23% (95% CI 19-28) for those with 0-3 MM (multivariate HR 1.58 [95%CI 1.18-2.11], P=.002] - Fig. 1A). Infectious complications were the most frequent cause of TRM in the group receiving dCBT with ≥ 4 allele MM (40%). Relapse, grade II-IV/III-IV acute and chronic GVHD were not significantly different between the two groups. Patients receiving CB units with 0-3 allele MM had a 4-year survival of 54% (95%CI 49-59) compared to 43% (95%CI 39-47) for those receiving units with ≥4 allele MM (multivariate HR 1.40 [1.11-1.78], P=.005 - Fig. 1B). The inferior OS associated with higher allele HLA disparity was only partially mitigated by increasing the TNC count in multivariate analysis (0-3 MM + TNC ≤ 3.9x10ˆ7/kg vs.0-3 MM + TNC > 3.9x10ˆ7/kg, HR 1.50 [0.97-2.32], P=.07; ≥4 MM + TNC > 4.9x10ˆ7/kg vs. 0-3 MM + TNC > 3.9x10ˆ7/kg, HR 1.42 [1.06-1.89], P=.02; ≥4 MM + TNC ≤ 4.9x10ˆ7/kg vs. 0-3 MM + TNC > 3.9x10ˆ7/kg, HR 1.66 [1.24-2.22], P=<.001 - Fig. 1C). Discussion: Our results confirm that allele-level HLA typing is a significant factor for OS following dCBT. The inferior OS associated with the increasing number of allele-level MM was driven by higher TRM. Selection of CB units with 0-3 allele-level MM is recommended. Figure 1View largeDownload PPTFigure 1View largeDownload PPT Close modal

Umbilical Cord Blood Microtransplantation in Newly Diagnosed, Elderly Patients with Acute Myeloid Leukemia

Objective: We observed the efficacy and safety of umbilical cord blood microtransplantation (UCBMT) in the treatment of newly diagnosed with acute myeloid leukemia (AML) in the elderly.Methods: Prospective one-arm phase I clinical study. The patients should meet the following criteria: 60-80-year-old; newly diagnosed AML; receive the treatment of chemotherapy combined with UCBMT.Result: In total, 11 patients newly diagnosed with AML received chemotherapy in combination with UCBMT, from November, 2019 to January, 2021, including 7 males and 4 females. The average age was 71 (60-80). For the patients, 7 cases with normal chromosome karyotype, and 2 cases with +8 chromosome, 1 case with 7q- chromosome, and 1 case with karyotype of monomer. In the 7 patients with normal chromosome karyotype, 3 cases were FMS-liketyrosine kinease 3 (FLT3) positive (2 of them in combination with nucleophosmin 1 (NPM1) mutation); in addition, in 4 patients of the 7, one showed double mutation of CEBPA, one showed NPM1 mutation, one showed IDH1 mutation, and one showed IDH2 mutation. In 4 patients with chromosomal abnormalities, one patient showed no special gene, one patient showed ASXL1 mutation, one patient was IDH1 mutation, and one patient was TP53 mutation. All of the patients were treated with IA (IDA 8-10 mg/ m 2/day x 3 days, cytarabine 100 mg/ m 2/day x 7 days) for inducing chemotherapy. For the patients with 60-70-year-old, they were treated with IDA (8 mg/ m 2/day); and for the patients with 70-80-year-old, they were treated with darubicin (10 mg/ m 2/day). In the consolidation phase, the patients were treated with cytarabine (1 g/ m 2, q12h) for 3 consecutive days. There were 3 courses of consolidation chemotherapy. Next, patients received single unrelated cord blood transplantation (UCBT) from China's public umbilical cord blood bank, HLA matching was performed for all patients before treatment. A total of 4 units of UCB with HLA 0-3/6（HLA-A,-B,-DR）matching and the ABO blood type matched with the patient were transfused after induction and consolidation chemotherapy for 24-48 hours, then with follow-up. At the same time, the immunological characteristics of these patients were fully analyzed. We demonstrated that, 8 of 11 patients received one course of induction chemotherapy, and achieved a complete response. The complete response rate was 72.7%. What's more, the median time for neutrophils ≥ 0.5 x 10 9/L and platelete ≥ 20 x 10 9/L was 12 days. There were no treatment-related deaths during induction therapy. The median follow-up was 14 (7-31) months. 1 patient showed monomer karyotype with P53 gene mutation, and got complete remission after one course of induction chemotherapy with IA. However, the patient died for AML recurred. For the other 10 patients, they were alive, and the OS of 1 year was 89.8%. Moreover, we found the expression of PD-1 on CD8 +T cells decreased, while the expression of CD38 increased after therapy. Besides, the proportion of NKp30 +NK cells, as well as the IFN-γ +TFN-α +NK cells increased significantly.Conclusion: UCBMT therapy for newly diagnosed elderly AML patients could accelerate the recovery of hematopoietic function and improve the safety of chemotherapy. This method is effective and worthy of further promotion. DisclosuresNo relevant conflicts of interest to declare.

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.

Unrelated cord blood stem cell transplantation for high-risk/refractory childhood acute myeloid leukemia: a clinical analysis of 160 cases

目的探讨单份非血缘脐血干细胞移植（UCBT）治疗高危/难治儿童急性髓系白血病（AML）的疗效。方法对2008年6月至2018年12月期间接受UCBT的160例高危/难治AML（不含急性早幼粒细胞白血病）患儿进行回顾性分析。全部病例均采用清髓性预处理方案，应用环孢素A（CsA）联合短程霉酚酸酯（MMF）预防移植物抗宿主病（GVHD）。结果160例AML患儿中男103例、女57例，中位年龄7（1～14）岁，中位体重23（8～77）kg。移植后42 d中性粒细胞累积植入率为95.0％（95％CI 90.0％～97.5％），移植后120 d血小板累积植入率为85.5％（95％CI 83.3％～93.4％），中性粒细胞、血小板植入中位时间分别为移植后16（11～38）d、35（13～158）d。Ⅱ～Ⅳ、Ⅲ～Ⅳ度急性GVHD发生率分别为37.3％（95％CI 29.3％～45.2％）、27.3％（95％CI 20.0％～35.0％），慢性GVHD发生率为22.4％（95％CI 15.5％～28.7％）。可评估的移植后360 d移植相关死亡率（TRM）为13.1％（95％CI 8.4％～18.9％）。移植后5年累积复发率为13.8％（95％CI 8.5％～20.3％），无病生存（DFS）率为71.7％（95％CI 62.7％～77.8％）、总生存（OS）率为72.2％（95％CI 64.1％～78.7％），无GVHD无复发生存（GRFS）率为56.1％（95％CI 46.1％～64.9％）。移植前处于第1次完全缓解（CR1）期（95例）、第2次完全缓解（CR2）期（28例）、未缓解患者（37例）的移植后5年累积复发率分别为5.3％（95％CI 1.9％～11.1％）、19.9％（95％CI 6.9％～37.7％）、30.9％（95％CI 14.3％～49.2％）（P＝0.001），移植后5年OS率分别为79.9％（95％CI 70.3％～86.7％）、71.1％（95％CI 50.4％～84.4％）、52.9％（95％CI 33.0％～69.3％）（χ2＝7.552，P＝0.020）。结论UCBT是治愈高危/难治儿童AML安全、有效的治疗方法。第1次完全缓解期进行UCBT有利于改善预后。

Low-Dose ATG Combined with Facybu Conditioning Regimen Followed By Single Unrelated Cord Blood Transplantation in Hematological Malignancies

Objective: This study aims to evaluate the efficacy and safety of low-dose ATG combined with FACyBu conditioning regimen for single unrelated cord blood transplantation in hematological malignanciesMethod: From Jul 2013 to Feb 2017, 30 patients of hematological malignancies (15 patients with ALL,11 patients with AML,3 patients with NHL,1 patient with CML ) who underwent unrelated cord blood transplantation were followed up. The median age was 24(3.16-46)years. Seventeen patients were in complete remission(CR) while 13 patients were in progressive stage. All the patients were pretreated with low dose ATG(Fresenius) (24patients 10.0mg/kg/d, 6 patients 5.0mg/kg/d;d-5,d-4) plus FACyBu(a myeloablative FA-BUCY protocol of 25 mg/m2/day Fludarabine and high-dose 2 g/m2/day Cytarabine for 5 consecutive days from day −13 to day −9, 1.8g/m2/day CY from day −8 to day −7, 3.2mg/kg/day BU from day −6 to day −4 and MCCNU 250mg /m2 d-3). Cyclosporine and mycophenolate were applied for Graft-versus-host disease (GVHD) prophylaxis. The GVHD, RFS, nonrelapse mortality, relapse mortality, OS, DFS and graft-versus-host disease-free/relapse-free survival (GRFS) probabilities were investigated. The side effects of the regimens were also evaluated.Result: The median CD34+ cell infusion quantity was 0.17 (0.07-1.26)*106/Kg. the median neutrophil engraftment time was 18(10-27)days and the median platelet engraftment time was 33(15-49)days. The cumulative incidence of grades II-IV acute GVHD was 23.5%. It's interesting that no grade III-IV acute GVHD was observed. The cumulative incidence of limited chronic GVHD and extensive chronic GVHD was 5.0% , 9.1% respectively. The median follow-up time was 10.8(2.6-46.1) months. The nonrelapse mortality, relapse mortality, OS, DFS and GRFS were 27.6%,10.9%,64.5%,64.4% and 61.4%, respectively. For the CR patients, the OS, DFS and GRFS were 85.9%, 85.9%, 80.2%, respectively. While for the nonremission patients, the OS, DFS and GRFS were 38.5%,28.5%, 38.5%Conclusion: The clinical efficacy of low-dose ATG combined with FACyBu conditioning regimen followed by single unrelated cord blood transplantation in hematological malignancies patients is similar to that of alternative allogeneic bone marrow transplantation as reported. The incidence of GVHD was low .The patients who were treated with this regimen experience good quality of life. DisclosuresNo relevant conflicts of interest to declare.

Outcomes of Cord Blood Transplantation for Adult Patients with Hodgkin Lymphoma, a Eurocord and EBMT Lymphoma Working Party Study

Allogeneic stem cell transplantation represents an alternative for relapsed or refractory patients (pts) with Hodgkin Lymphoma (HL). In this setting, only limited data on unrelated umbilical cord blood transplantation (UCBT) are available. We analyzed 133 adult pts with HL who underwent UCBT in EBMT centers. Histological subtype was nodular sclerosis in 65% of the pts. Median age at UCBT was 29 (18-65) years. Median follow-up was 37 (2-119) months and median year of UCBT was 2010 (2003-2015). Ninety pts had received a previous autologous transplantation (ASCT), while 19 had received 2 ASCT before UCBT; median time from ASCT to UCBT was 15 (2-281) months. Disease status at UCBT was complete remission (CR) in 45%, partial remission (PR) in 28% and relapse or refractory disease in 27% of the pts. Sixty percent of pts were male and 54% had a positive cytomegalovirus serology. Fifty-one percent (n=68) received a single UCBT and 49% (n=65) a double UCBT; 58% of pts received a graft with 2 or more HLA mismatch. The majority of the pts (n=104, 77%) underwent a reduced intensity conditioning regimen, the most frequent conditioning regimen (n=69) being Cyclophosphamide + Fludarabine + Total Body Irradiation (TBI) (2 Gy). Forty percent (n=46) of pts received anti-thymocyte globulin and Cyclosporine A + mycophenolate mofetil prophylaxis was given to 60% (n=80) of the pts. Median total nucleated cell (TNC) dose at cryopreservation was 3.99 (1.5-12.2) x107/Kg.The cumulative incidence (CI) of neutrophil engraftment at 60 days was 87% (81%-93%). The 100-day CI of acute grade II-IV GVHD was 26% (19%-35%). At 3 years, chronic GVHD was 30% (21%-41%). Relapse incidence (RI) and non-relapse mortality (NRM) were 40% (32%-50%) and 30% (23%-40%) at 3 years, respectively. The overall survival (OS) was 48% (39%-57%) and progression free survival (PFS) was 28% (21%-37%) at 3 years. Sixty-nine patients died: 27 of relapse and 39 of transplant related causes (infections, n=13, GVHD, n=7, idiopathic pneumonia syndrome n=6, EBV-PTLD n=2, VOD n=2 and others causes, n=9). According to disease status at UCBT, OS at 3 years was 68% (55%-79%) for pts in CR, 31% (18%-50%) for pts in PR and 26% (14%-44%) for pts in relapsed or refractory disease.In multivariate analysis, adjusted for median year of UCBT, Cyclophosphamide + Fludarabine + low dose TBI conditioning regimen, disease status at UCBT, conditioning intensity and type of UCBT, none of these factors were found to be associated with acute or chronic GVHD. 3-year RI and NRM were higher for pts in relapse or refractory disease at UCBT compared to pts in CR (HR=2.62, 95%CI 1.12-6.11, p=0.03 and HR=3.66, 95%CI 1.52-8.80, p=0.004, respectively). The use of Cyclophosphamide + Fludarabine + low dose TBI conditioning regimen was associated with a lower risk of NRM (HR=0.38, 95%CI 0.15-0.95, p=0.04) and also with a better OS (HR=0.37, 95%CI 0.18-0.76, p=0.006). OS was significantly worse for pts who underwent UCBT in PR (HR=1.97, 95%CI 1.02-3.80, p=0.04) and for those in relapse or refractory disease at transplant (HR=2.86, 95%CI 1.41-5.81, p=0.004). Pts transplanted in relapse or refractory disease have also a lower PFS (HR=3.12, 95%CI 1.71-5.71, p<0.001).In conclusion, UCBT is feasible in heavily pretreated pts with HL, if there are no other alternative donors. Conditioning with Cyclophosphamide + Fludarabine + low dose TBI is associated with a better OS and NRM. However, outcomes are poor for patients not in CR at the time of UCBT and one might consider the use of new therapeutic agents earlier before UCBT in this setting. DisclosuresZuckerman:BioSight Ltd.: Consultancy. Snowden:Sanofi: Honoraria. Robinson:Gilead: Honoraria, Other: Travel Grants; Takeda: Consultancy, Honoraria, Other: Travel Grants; Roche: Honoraria, Other: Travel Grants; Riemser: Consultancy.

Incidence and risk factors of late-onset hemorrhagic cystitis after single umbilical cord blood transplantation with myeloablative conditioning regimen.

To explore the incidence and risk factors of late-onset hemorrhagic cystitis (LOHC) in patients undergoing single umbilical cord blood transplantation for hematological malignancies. Clinical data from 234 patients who consecutively underwent single UCBT using a myeloablative conditioning regimen without antithymocyte globulin in our center were retrospectively analyzed. In total, 64 (27.4%) patients developed LOHC with a median onset time of 40.5 (range 8-154) days, and 15 (6.4%) patients gradually developed grade III-IV LOHC. The incidence of LOHC was marginally higher in adults (31.0%) than in children (23.7%) (p = 0.248). HLA matching ≤ 6/8 (HR = 2.624, 95% CI 1.112-6.191, p = 0.028) was an independent risk factor for LOHC. The overall survival of LOHC patients (59.8%, 95% CI 61.7-85.5%) was significantly lower than that of patients without LOHC (86.8%, 95% CI 79.6-91.6%) at 130days post transplantation (p = 0.036). Patients with less well-matched grafts have a higher incidence of LOHC. Inherent deficiencies in immunity in the context of HLA disparity and more intense pharmacologic immunosuppression after severe acute graft-versus-host disease may contribute to viral activation. Prevention and treatment of LOHC have the potential to prolong long-term survival.

Phase I Dose-Finding, Safety, and Tolerability Trial of Romiplostim to Improve Platelet Recovery After UCB Transplantation

Platelet recovery is delayed after umbilical cord blood transplant (UCBT). Romiplostim is a thrombopoietin receptor agonist that has the potential to improve platelet engraftment after UCBT. The purpose of this study was to determine the safety profile and maximum tolerated dose (MTD) of romiplostim and to investigate whether romiplostim accelerates platelet recovery post-UCBT. It was a single-center, dose-finding, safety and tolerability phase I trial of weekly romiplostim in 20 adult patients who failed to achieve an un-transfused platelet count of 20×109/L by day +28 post-UCBT. Romiplostim was administered at the assigned dose as 6 weekly injections beginning by day +42 post-UCBT. Four dose levels (4, 6, 8, and 10 µg/kg per dose) were evaluated. The MTD of romiplostim was determined by the continual reassessment method, with a goal to identify a dose level with desired toxicity rate of ≤20%. Median age of the patients was 59.5 years, and 60% were female. Eleven patients received nonmyeloablative (NMA) double UCBT, seven patients received myeloablative single UCBT, and two patients received NMA single UCBT. Two patients received 4 µg/kg per dose, two received 6 µg/kg per dose, four received 8 µg/kg per dose, and the remaining 12 received 10 µg/kg per dose. Only five patients completed the full six doses of treatment. Of the 15 patients who received fewer than six doses, 12 were due to a platelet count of >100×109/L, two were due to platelet count of >400×109/L, and one was due to right upper extremity edema without thrombosis. All romiplostim-treated patients achieved platelet engraftment to 20×109/L at a median of 45 days post-UCBT compared to 90% of controls at a median of 45 days (P=.08). Similarly, 90% of romiplostim-treated patients achieved platelet engraftment to 50×109/L at a median of 48 days compared to 75% of controls at a median of 52 days (P=.09). All dose levels were effective with low toxicity; therefore, the MTD of romiplostim was 10 µg/kg per dose, and romiplostim is a safe and potentially effective therapy to counter delayed platelet recovery post-UCBT.

An Encouraging Successful Result of Allogeneic Hematopoietic Stem Cell Transplantation in a Boy Both with Juvenile Myelomonocytic Leukemia and Osteogenesis Imperfecta : A Case Report

Background: Juvenile myelomonocytic leukemia (JMML) is a rare hematologic malignancy in young children that is classified as a myelodysplastic/myeloproliferative neoplasm and not only characterized by young age, hepatosplenomegaly, thrombocytopenia and monocytosis, but also by molecular aberrations in the RAS-RAF-MEK-ERK signaling pathway and GM-CSF-hypersensitivity. Most children with JMML experience an aggressive clinical course and the only curative treatment option for these children is stem cell transplantation (SCT). Osteogenesis imperfect (OI) is also an orphan inherited monogenic bone fragility disorder that usually is caused by mutations in one of the two genes coding for collagen type I alpha chains, COL1A1 or COL1A2. A common issue associated with the molecular abnormality is a disturbance in bone matrix synthesis and homeostasis inducing bone fragility. In very early life, this can lead to multiple fractures and progressive bone deformities. Current multidisciplinary management could only improve quality of life for patients, including physical therapy, drug treatment and orthopaedic surgery. Innovative therapies, such as progenitor and mesenchymal stem cell or bone marrow transplantation, targeting the specific altered pathway rather than the symptoms, may develop new curative treatments. Here we report a 3-year-old boy who suffered from both JMML and OI, was successfully transplanted and kept presenting an encouraging outcome up to now. Aims:To investigate the possible efficacy and safety of Allogeneic Hematopoietic Stem Cell Transplantation in a boy both with Juvenile Myelomonocytic Leukemia and Osteogenesis Imperfecta. Methods:A 3-year-old boy presented with fatigue, fever, petechia and rash in Aug 2019, accompanying with loss of appetite, joint pain and severe hepatosplenomegaly. The boy had a special appearance of short stature and blue sclerae, meanwhile he suffered intermittent eczema and bone fracture twice since he was 2 years old. Similar characteristics were also positive in his grandmother, father and father's sister. The blood cell counts revealed anemia, thrombocytopenia and leukocytosis especially monocytosis. Bone marrow aspirate showed excessive proliferation of myelomonocytic cells and hypersensitivity to granulocyte-macrophage colony-stimulating factor in vitro. Somatic mutation of gene NF1, PTPN11 and COL1A1 were identified by Next Generation Sequencing.Therefore, the little boy was diagnosed with two rare diseases of Juvenile Myelomonocytic Leukemia and Osteogenesis Imperfecta at the same time. After 4 courses of hypomethylating agents therapy, the boy underwent haploidentical allogeneic bone marrow stem cell transplantation combined with allogeneic single umbilical cord blood transplant in May 2020. The myeloablative conditioning regimen was composed of Decitabine (20mg/m2/day, days -13 to -9), Cyclophosphamide (25mg/kg/day, days -8 and -7), Busulfan(100mg/m2/day, days -6 to -3), Fludarabine (40mg/m2/day, days -6 to -2) and Cytarabine (100mg/m2/day, days -6 to -2). Post-Cyclophosphamide (50mg/kg/day, days +3 and +4), tacrolimus and mycophenolate mofetil were used for prophylaxis of graft-versus-host disease (GVHD). Results:The number of infused TNCs from haplo-bone marrow and cord blood unit was 41.4×10^8/kg and 9.72×10^7/kg, respectively, while the number of infused CD34+ cells was 11.84×10^6/kg and 2.33×10^5/kg, respectively. The boy achieved sustained engraftment of both neutrophils and platelets at 16 days and 24 days, respectively, with complete haplo-donor chimerism of confirmed at 14 days. He developed grade III acute GVHD (skin, gut and liver) and recovered at 39 days after transplant. Clinical symptoms such as rash, joint pain and hepatosplenomegaly got complete remission, and the mutated genes like NF1, PTPN11 and COL1A1 all disappeared at 30 days. At the time of this report, the boy was alive with negative MRD and good quality of life with a follow-up of 3 months after HCT. Conclusion:To our knowledge, this is the first report that a child both with Juvenile Myelomonocytic Leukemia and Osteogenesis Imperfecta was cured by allogeneic hematopoietic stem cell transplantation.Our experience suggests that allogeneic bone marrow transplantation may be a novel safe and effective therapeutic strategy for OI patients. Disclosures No relevant conflicts of interest to declare.

Reduced-Intensity versus Myeloablative Conditioning in Cord Blood Transplantation for Acute Myeloid Leukemia (40-60 years) across Highly Mismatched HLA Barriers-On Behalf of Eurocord and the Cellular Therapy & Immunobiology Working Party (CTIWP) of EBMT.

The use of myeloablative conditioning (MAC) in umbilical cord blood transplantation (UCBT) has been associated with high nonrelapse mortality (NRM) in patients aged >40 years, especially those having a high HLA disparity, thus limiting wider applications. We hypothesized that the NRM advantage of reduced-intensity conditioning (RIC) and higher graft-versus-leukemia effect associated with greater HLA disparities would expand its use for patients (aged 40 to 60 years) without compromising efficacy and compared outcomes between RIC and MAC regimens. In total, 288 patients aged 40 to 60 years, with de novo acute myeloid leukemia, receiving UCBT with at least 2 HLA mismatches with RIC (n=166) or MAC (n=122) regimens were included. As compared to RIC, the MAC cohort included relatively younger patients, having received more single UCBT, with lower total nucleated cell counts and more in vivo T cell depletion. Median time to neutrophil engraftment, infections (bacterial, viral, and fungal), and grade II to IV acute and chronic graft-versus-host disease were similar in both groups. In the multivariate analysis, overall survival (hazard ratio [HR], 0.98; P=.9), NRM (HR, 0.68; P=.2), and relapse (HR, 1.24; P=.5) were not different between RIC and MAC. Refractory disease was associated with worse survival. Outcomes of UBCT for patients aged 40 to 60 years having ≥2 HLA mismatches are comparable after the RIC or MAC regimen.

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.

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.

Effect of KIR/HLA receptor-ligand mode on prognosis of single unrelated cord blood transplantation in patients with hematological malignancies

目的探讨自然杀伤细胞免疫球蛋白样受体（KIR）与人类白细胞抗原（HLA）受配体模式对血液病患者单份非血缘脐血移植（sUCBT）预后的影响。方法回顾性分析2012年7月至2018年6月270例接受sUCBT的血液病患者。移植前脐血及患者均进行HLA12个位点高分辨配型，选择移植物（脐血）的KIR均同时表达2DL1和2DL2/2DL3抑制性基因，根据患者KIR配体情况分为缺失组（C1/C1或C2/C2）和无缺失组（C1/C2）。结果270例血液病患者中男146例（54.1％），女124例（45.9％），中位年龄13（1～62）岁；缺失组174例（64.4％），无缺失组96例（35.6％）。全部患者均采用不含抗胸腺细胞球蛋白（ATG）清髓性预处理方案。缺失组、无缺失组粒细胞植入率均为98.9％（172/174、95/96），中位植入时间分别为16（10～41）d、17（11～33）d（P＝0.705）；血小板植入率分别为88.5％（154/174）、87.5％（84/96），中位植入时间分别为35（11～113）d、38.5（13～96）d（P＝0.317）；缺失组、无缺失组Ⅱ～Ⅳ级急性GVHD发生率分别为38.7％（95％CI 31.4％～45.9％）、50.0％（95％CI 39.6％～59.6％）（P＝0.075），多因素分析显示KIR配体缺失是影响Ⅱ～Ⅳ度急性GVHD发生的独立保护性因素（P＝0.036）。移植后3年累积复发率分别为17.7％（95％CI 11.7％～24.9％）、22.7％（95％CI14.4％～32.2％）（P＝0.288）。中位随访时间742（335～2 512）d，缺失组、无缺失组3年总生存率分别为72.1％（95％CI 64.1％～78.6％）、60.5％（95％CI 47.9％～69.2％）（χ2＝3.629，P＝0.079），3年无病生存率分别为64.9％（95％CI 56.2％～72.3％）、55.4％（95％CI 44.4％～65.0％）（χ2＝3.027，P＝0.082），移植后180 d 非复发死亡率分别为12.1％（95％CI 7.7％～17.4％）、16.7％（95％CI 10.0％～24.8％）（P＝0.328）。结论在不含ATG清髓性预处理sUCBT血液病治疗体系中，缺失抑制性KIR配体患者移植后急性GVHD发生率更低。

Role of HLA Matching in Single Umbilical Cord Blood Transplantation Outcomes.

Role of HLA Matching in Single Umbilical Cord Blood Transplantation Outcomes.

Unlicensed Umbilical Cord Blood Units Provide a Safe and Effective Graft Source for a Diverse Population: A Study of 2456 Umbilical Cord Blood Recipients.

Umbilical cord blood (UCB) transplantation (UCBT) is a curative procedure for patients with hematologic malignancies and genetic disorders and expands access to transplantation for non-Caucasian patients unable to find a fully matched unrelated donor. In 2011, the US Food and Drug Administration required that unrelated UCBT be performed using either licensed UCB or unlicensed UCB under the Investigational New Drug (IND) program. The National Marrow Donor Program manages an IND under which 2456 patients (1499 adults and 957 children, 564 with malignant diseases and 393 with nonmalignant diseases) underwent single or double UCBT between October 2011 and December 2016. The median patient age was 31 years (range, <1 to 81 years), and 50% of children and 36% of adults were non-Caucasian. The median time to neutrophil engraftment (ie, absolute neutrophil count ≥500/mm3) was 22 days for adults, 20 days for pediatric patients with malignant diseases, and 19 days for pediatric patients with nonmalignant diseases, with corresponding rates of engraftment at 42 days of 89%, 88%, and 90%. In these 3 groups of patients, the incidence of acute graft-versus-host disease (GVHD) grade II-IV was 35%, 32%, and 24%; the incidence of chronic GVHD was 24%, 26%, and 24%; and 1-year overall survival (OS) was 57%, 71%, and 79%, respectively. In multivariate analysis, younger age, lower Hematopoietic Cell Transplantation-Specific Comorbidity Index, early-stage chemotherapy-sensitive disease, and higher performance score were predictive of improved OS for adults. In a subset analysis of children with malignancies undergoing single UCBT, the use of either licensed UCB (n=48) or unlicensed UCB (n=382) was associated with similar engraftment and survival. The use of unlicensed UCB units is safe and effective and provides an important graft source for a diverse population.

Romiplostim Improves Platelet Recovery after UCB Transplant

Background: Prolonged thrombocytopenia after hematopoietic stem cell transplant is a relatively common complication associated with intricate mechanisms including impaired thrombopoiesis and increased platelet turnover. Platelet recovery is particularly delayed after umbilical cord blood transplant (UCBT). Romiplostim is a thrombopoietin receptor agonist that is FDA approved for the treatment of chronic ITP. Although an increasing number of studies recently show promising results on the use of romiplostim in chemotherapy induced thrombocytopenia, the effect of romiplostim on platelet recovery in patients with persistent thrombocytopenia after UCBT remains unknown. Objectives: The primary objective of the study was to determine the maximum tolerated dose (MTD) of romiplostim in patients who failed to achieve platelet recovery by day +28 after UCBT. Secondary objectives were to determine if romiplostim influences the speed of platelet recovery, decreases the risk of thrombocytopenia related complications or affects the incidence of bone marrow (BM) fibrosis or relapse. Methods: This was a single center dose escalation trial of weekly romiplostim in patients &gt;18 years who failed to achieve an untransfused platelet count (PLT) of 20 x 109/L by day +28 after myeloablative (MA) or nonmyeloablative (NMA) UCBT. A total of 21 patients were enrolled from April 2015 to December 2018. One patient withdrew and was replaced so 20 patients are included in the analysis. Romiplostim was administered at the assigned dose as 6 weekly injections beginning by day +42 post UCBT with an end date by day +100. Four dose levels (4, 6, 8, and 10 mcg/kg/dose) were evaluated. There was no intra-patient dose escalation. The MTD of romiplostim was determined by the Continual Reassessment Method, with a goal to identify a dose level which corresponds to the desired toxicity rate of £ 20%. Toxicities of interest included thrombosis, PLT&gt;400x109/L and any grade 4-5 adverse event (AE) attributed to romiplostim. The comparison group were historical controls selected from our prospectively collected database based on age, gender, underlying disease, conditioning intensity and transplant type (1:1 matching). Results: Median (range) age of the patients was 59.5 (18-68) years and 60% were female. Ten patients had AML, 5 ALL, 3 MDS, 1 NHL and 1 MM. Of those, 11 received NMA double UCBT, 7 MA single UCBT and 2 received NMA single UCBT. Two patients received 4 mcg/kg/dose, two 6 mcg/kg/dose, four 8 mcg/kg/dose and the remaining 12 received 10 mcg/kg/dose. Only 5 patients completed the full 6 doses of treatment. Of the 15 patients who received less than 6 doses, 12 were due to a PLT&gt;100×109/L, 2 due to PLT&gt;400×109/L, and 1 was due to physician choice after the subject developed right upper extremity edema (without thrombosis). As shown in figure 1, 100% of romiplostim treated patients achieved platelet engraftment to 20 x 10^9/L at a median of 45 days post UCBT compared to 85% of controls who achieved platelet engraftment at a median of 49 days (p=0.07). Similarly, 90% of romiplostim treated patients achieved platelet engraftment to 50 x 10^9/L at a median of 48 days compared to 70% of historical controls who achieved platelet engraftment at a median of 52 days (p=0.04). The most common AEs were insomnia (30%), arthralgia (25%), myalgia (20%), headache (20%), dizziness and abdominal pain (15%). Only three patients experienced serious AEs requiring discontinuation of the drug: two had a PLT&gt;400x109 /L (without complications) and one developed right upper extremity edema. Bleeding episodes improved with the use of the drug as well as need of transfusions (patients vs controls, p&lt;0.05). All dose levels appear to be effective with overall low toxicity. Therefore, the MTD of romiplostim was 10mcg/kg/dose. All study patients were evaluated for BM fibrosis and relapse at regular intervals. There were no BM findings suggestive of increased fibrosis or relapse by day +100, and peripheral blood morphology was normal (no significant dacryocytosis, normal platelet morphology). Conclusion: Our study showed that romiplostim was well tolerated and accelerates platelet engraftment in patients undergoing UCBT, with the MTD being 10mcg/kg/dose. These results indicate that romiplostim is safe and potentially effective therapy to improve platelet recovery after UCBT. Further studies in larger numbers of patients are needed to confirm these observations. Disclosures Wagner: BlueRock: Research Funding; Rocket Pharmaceuticals: Consultancy; Novartis: Research Funding; Magenta: Consultancy, Research Funding; Gadeta: Membership on an entity's Board of Directors or advisory committees. Brunstein:Gamida: Research Funding; Magenta: Research Funding; Astex: Research Funding. Bejanyan:Kiadis Pharma: Other: advisory board. Smith:Amgen: Research Funding; Jazz Pharmaceuticals: Research Funding. OffLabel Disclosure: Romiplostim (Nplate) is an FDA approved drug for chronic ITP. In this study (phase I trial) we aimed to evaluate the safety and effectiveness of romiplostim on platelet recovery following UCBT.