Unrelated Donor Transplantation Research Articles

Reply to: Disparities in Allograft Access in the Era of Post-Transplant Cyclophosphamide-Based Mismatched Unrelated Donor Transplantation.

Reply to: Disparities in Allograft Access in the Era of Post-Transplant Cyclophosphamide-Based Mismatched Unrelated Donor Transplantation.

Novel Scoring System for Ranking Hematopoietic Stem Cell Transplantation.

When human leukocyte antigen (HLA)-matched donors are not available for hematopoietic stem cell transplants (HSCT), there are no well-accepted guidelines for ranking 7/8 HLA-matched unrelated donors to achieve optimal transplant outcomes. A novel scoring system for ranking HLA mismatches for these donors was investigated. High-resolution HLA types were used to determine amino acid mismatches located in the HLA antigen-recognition domain. The location and physicochemical properties of mismatched amino acids were used to assign scores for peptide binding, T-cell receptor docking, and HLA structure/function. The scores were tested using a cohort of 2319 patients with leukemia or myelodysplastic syndrome who received their first unrelated donor transplant using conventional graft-versus-host disease (GVHD) prophylaxis between 2000 and 2014. Donors were 7/8 HLA-matched with a single HLA Class I mismatch. Primary outcomes were overall survival and acute GVHD. The scores did not significantly (p<0.01) associate with transplant outcomes, although a Peptide Score = 0 (i.e., no differences in peptide binding; N=146, 6.3%) appears to have lower transplant-related mortality (TRM) compared to higher scores (p=0.019). HLA mismatches with Peptide Score=0 were predominately HLA-C*03:03/03:04 (62%), previously reported to be a permissive mismatch, and a group of 28 other HLA mismatches (38%) that showed similar associations with TRM. This study suggests that HLA mismatches that do not alter peptide binding or orientation (Peptide Score=0) could expand the number of permissive HLA mismatches. Further investigation is needed to confirm this observation and to explore alternative scoring systems for ranking HLA mismatched donors.

Comparison of HLA-haploidentical donors with post-transplant cyclophosphamide versus HLA-matched unrelated donors in peripheral blood stem cell transplantation for acute myeloid leukaemia.

HLA-haploidentical haematopoietic cell transplantation with post-transplant cyclophosphamide (PTCy-haplo) is emerging as an effective alternative due to donor availability and safety. We conducted a nationwide retrospective study comparing the outcomes of PTCy-haplo with both anti-thymocyte globulin (ATG)-free and ATG-administered matched unrelated donors (MUD) transplantation, using peripheral blood stem cells as the first transplantation for acute myeloid leukaemia (AML). Our study showed a lower and slower haematopoietic recovery and a higher incidence of infection-related deaths after PTCy-haplo than after MUD transplantation. In addition, we revealed an increased risk of acute and chronic graft-versus-host disease (GVHD) in ATG-free MUD transplantation in comparison to PTCy-haplo. For grades III-IV acute GVHD, the hazard ratio (HR) was 2.71 (95% CI, 1.46-5.01), and for extensive chronic GVHD, the HR was 3.11 (95% CI, 2.07-4.68). There was no significant difference regarding overall survival amongst the groups. In addition, GVHD-free relapse-free survival (GRFS) was lower in ATG-free MUD transplantation than in PTCy-haplo (HR, 1.46; 95% CI, 1.17-1.82). Notably, ATG-administered MUD transplantation showed no significant difference in GRFS from PTCy-haplo, negating the advantage of PTCy. Our results suggest that PTCy-haplo could be viable for AML patients without an HLA-matched related donor.

Post-transplant cyclophosphamide with post-engraftment anti-thymocyte globulin reduce moderate to severe chronic graft-versus-host disease in peripheral stem cell transplantation from HLA-matched unrelated and haploidentical donors.

Post-transplantation cyclophosphamide (PTCy) has unique advantages for graft-versus-host disease (GVHD) prophylaxis after allogeneic hematopoietic stem cell transplantation (allo-HSCT). In this single-center retrospective landmark analysis, we evaluated chronic GVHD (cGVHD) and clinical outcomes in patients receiving PTCy, tacrolimus, and post-engraftment low-dose anti-thymocyte globulin (PTCy-ATG) as GVHD prophylaxis after HLA-matched unrelated or haploidentical donor transplantation. Two historical patient groups receiving calcineurin inhibitor-based GVHD prophylaxis were used as control groups. A total of 71 patients with myeloid malignancies undergoing allo-HSCT with myeloablative conditioning regimens were included in the analysis. The 3-year cumulative incidences of cGVHD and moderate to severe cGVHD (M/S cGVHD) were 39.2% (95%CI 27.4%-51.0%) and 11.5% (95%CI 4.1%-18.9%), respectively, in the PTCy-ATG group, and only one instance of bronchiolitis obliterans (BO) was observed. The disease-free survival (DFS), overall survival (OS), and GVHD-free and relapse-free survival rates were 94.0% (95%CI 88.3%-99.7%), 93.0% (95%CI 87.1%-98.9%) and 83.8% (95%CI 75.0%-92.6%) respectively. Of note, the PTCy-ATG group presented with a significantly lower incidence of M/S cGVHD and BO, which translated into superior OS in multivariate analysis. In this retrospective analysis, we observed that PTCy-ATG-based GVHD prophylaxis was associated with a lower incidence of M/S cGVHD and better transplantation outcomes beyond day 100, which invites prospective evaluation.

Long-term outcome of 2-year survivors after allogeneic hematopoietic cell transplantation for acute leukemia.

Information on late complications in patients with acute leukemia who have undergone allogeneic hematopoietic cell transplantation (HCT) is limited. We performed a left-truncated analysis of long-term survival in patients with acute leukemia who were alive and disease-free 2 years after HCT. We included 2701 patients with acute lymphoblastic leukemia (ALL) and 9027 patients with acute myeloid leukemia (AML) who underwent HCT between 2005 and 2012. The 10-year overall survival (OS) rate was 81.3% for ALL and 76.2% for AML, with the main causes of late mortality being relapse (ALL-33.9%, AML-44.9%) and chronic graft-versus-host disease (ALL-29%, AML-18%). At 10 years, HCT-related mortality was 16.8% and 20.4%, respectively. Older age and unrelated donor transplantation were associated with a worse prognosis for both types of leukemia. In addition, transplantation in the second or third complete remission and peripheral blood HSC for ALL are associated with worse outcomes. Similarly, adverse cytogenetics, female donor to male patient combination, and reduced intensity conditioning in AML contribute to poor prognosis. We conclude that 2-year survival in remission after HCT for acute leukemia is encouraging, with OS of nearly 80% at 10 years. However, the long-term mortality risk of HCT survivors remains significantly higher than that of the age-matched general population. These findings underscore the importance of tailoring transplantation strategies to improve long-term outcomes in patients with acute leukemia undergoing HCT.

Total Marrow and Lymphoid Irradiation (TMLI) Is Associated with Good Early Outcomes in Patients Undergoing Matched Sibling Donor and Haplo-identical Transplants for Acute Lymphoblastic Leukemia

Total marrow and lymphoid irradiation [TMLI] can deliver higher doses of irradiation without increased toxicity. This study evaluated TMLI and Cyclophosphamide in patients undergoing stem cell transplantation for acute lymphoblastic leukemia [ALL] . Fifty-eight patients underwent matched related, unrelated or haplo-identical donor transplant using TMLI. The graft source was PBSC in all while GVHD prophylaxis consisted of cyclosporine with methotrexate or post-transplant cyclophosphamide. The median age was 20 years [range: 5 - 49] and included 20 children. Engraftment occurred in 56 [96.5%] at median of 15 days [range: 12 - 23] with 2 early deaths. Sinusoidal obstruction syndrome [SOS] was seen in 10 patients while hemorrhagic cystitis and cardiac dysfunction occurred in 2 patients each. Cumulative incidence of grade II - IV acute GVHD was 23.6% while grade III - IV was 10.9%. Chronic GVHD was seen in 46.9% while relapse was seen in 10 patients [17.2%]. The 2-year overall survival [OS] was 65.9 ± 6.8% and 2-year disease free survival [DFS] was 59 ± 6.7%. Outcomes were compared with 52 patients who received either Cy/TBI or Flu/Bu4 for conditioning during the same period. Engraftment rates and time to engraftment were similar. Acute GVHD [p = 0.002], regimen related toxicity [p = 0.043] and Day 100 non-relapse mortality [p = 0.020] were significantly lower with TMLI. TMLI was associated with better OS [p = 0.004] and DFS [p = 0.005] for haplo-identical transplants. Better DFS was seen with TMLI in patients with high-risk disease [p = 0.007] and disease status > CR1 [p = 0.041]. The use of TMLI and cyclophosphamide is associated with good outcomes in patients undergoing HSCT for ALL especially with haploidentical stem cell transplants.

Long-term survival after unrelated donor marrow transplantation for aplastic anaemia after optimized conditioning regimen: a retrospective multicentre cohort study

Almost all acquired severe aplastic anaemia is immune mediated and characterised by hypocellular bone marrow and ≥2 affected haematopoietic lineages. The optimal preparartive regimen for unrelated donor transplantation remains to be established. We aimed to study long-term outcomes after unrelated donor transplantation for severe aplastic anaemia with de-escalation of cyclophosphamide (Cy) dose in steps of 50mg/kg (150, 100, 50, 0mg/kg) in combination with total body irradiation (TBI) 2Gy, anti-thymocyte globulin (ATG) and fludarabine. Ninety-six patients with severe aplastic anaemia aged ≤65 years with adequate organ function enrolled on a trial of human leukocyte antigen (HLA)-matched or 1 HLA-locus mismatched unrelated donor marrow transplantation conducted between 02/2006 and 12/2013 in the United States (NCT00326417). Exclusion criteria were Karnofsky performance status of less than 60, clonal cytogenetic abnormalities and inherited marrow failure syndormes. The primary outcome was day-100 engraftment (achievement of absolute neutrophil recovery to at least 0.5×109/L without subsequent decline) and day-100 survival. The trial determined the lowest effective Cydose as 50mg/kg (n=38) for day-100 engraftment and survival. Cy dose 100mg/kg (n=41) was also acceptable. Accrual to Cy doses 150mg/kg (n=15) and 0mg/kg (n=3) was terminated early for toxicities. The current study is an extended follow up of patients enrolled on the trial (NCT00326477) and includes 76 of 96 patients alive ≥1 year after transplantation. There were 20 deaths in the first year after transplantation (Cy 0mg/kg [n=2], Cy 50mg/kg [n=1], Cy 100mg/kg [n=10], Cy 150mg/kg [n=7]). Patients were followed prospectively from transplantation and data reported using standardized data collection forms until death, loss to follow up or last contact through November 2023. The incidence of graft failure was calculated using the cumulative incidence estimator and the probability of survival using the Kaplan-Meier estimator. The median follow up of the cohort is 8.02 (IQR) 5.16-10.12) years. With Cy 50mg/kg, there was one graft failure and five deaths ≥1 year after transplantation. With Cy 100mg/kg there was only one late death and no graft failure. The 8-year probabilities of survival were 85.0% (95% CI 67.3-93.5) and 75.6% (95% CI 59.4-86.1) after Cy50mg/kg and 100mg/kg, respectively, P=0.31. With Cy 0mg/kg and 150mg/kg, there were no graft failures or death ≥1 year after transplantation. Regardless of Cy dose 12 of 15 patients aged ≥50 years died. Cy 50mg/kg or 100mg/kg with TBI 2Gy, ATG and fludarabine are effective conditioning regimens for unrelated donor marrow transplants for aplastic anaemia. Identification of an optimized transplantation approach for patients aged ≥50 years is needed. US National Institutes of Health.

Hematopoietic cell transplantation for DOCK8 deficiency: Results from a prospective clinical trial

DOCK8 deficiency is a primary immunodeficiency in which allogeneic hematopoietic cell transplantation (HCT) represents the only known cure. We tested the ability of a busulfan-based regimen to achieve reliable engraftment and high levels of donor chimerism with acceptable toxicity in a prospective clinical trial in DOCK8 deficiency. To both evaluate the ability of HCT to reverse the clinical phenotype and to correct the immunologic abnormalities by 1 year post HCT. We conducted a prospective HCT trial for recipients with DOCK8 deficiency. Subjects were recruited from October 5, 2010, to December 30, 2022. Donor sources included fully matched related and unrelated donors and haploidentical donors. The reduced toxicity, myeloablative conditioning regimen contained no serotherapy. Graft-versus-host disease (GVHD) prophylaxis included either a calcineurin inhibitor with methotrexate or post-HCT cyclophosphamide (PT/Cy) followed by tacrolimus and mycophenolate mofetil. The trial was later amended to study PT/Cy in all patients. (Pilot Study of Reduced-Intensity Hematopoietic Stem Cell Transplant of DOCK8 [NCT01176006].) RESULTS: Thirty-six subjects, both children and adults (median age 16.4 years), underwent HCT for DOCK8 deficiency. Most patients, 33 of 36 (92%), achieved full (≥98%) donor chimerism in whole blood as early as day+30. With a median potential follow-up of 7.4 years, 29 (80.6%) were alive with no evidence of new DOCK8 deficiency-related complications. PT/Cy was effective in reducing the risk of acute GVHD in patients who had received matched unrelated donor and haploidentical transplants, but it was associated with transient delays in immune-reconstitution and hemorrhagic cystitis. A busulfan-based HCT regimen using PT/Cy for GVHD prophylaxis and a broad range of donor types and hematopoietic cell sources were well tolerated, leading to the reversal of the clinical immunophenotype.

Real-World Impact of Routine Addition of Antithymocyte Globulin to Standard GVHD Prophylaxis in Myeloablative Unrelated Donor Transplants: Important Gains in Graft-versus-Host Disease Prevention though No Difference in Overall Survival

Introduction: Antithymocyte globulin (ATG) has been demonstrated to reduce the incidence of graft-versus-host disease (GVHD); however, it remains controversial whether these gains are offset by an increase in relapse. Methods: We conducted a retrospective historical control study consisting of patients (n = 210) who underwent myeloablative allogeneic hematopoietic stem-cell transplantation (HSCT) from 2014 to 2020. Results: The incidence of acute GVHD was lower in the ATG group (51.4%) than the non-ATG group (control) (70.0%, p = 0.010). The incidence of chronic GVHD was also lower in the ATG group at 1-year (36.4% vs. 62.9%, p < 0.001) and 2-year (40.0% vs. 65.7%, p < 0.001) post-HSCT. The mortality due to GVHD was higher in the control (18.5%) than the ATG group (4.3%; p = 0.024). The severe GVHD-relapse-free survival was higher in the ATG group (36.4%) than the control (12.9%; p < 0.001). Nevertheless, the 2-year overall survival was similar. Conclusion: Our results confirm the effectiveness of ATG in prevention of GVHD in the real-world setting and enhanced GVHD-free survival. An important result is the equalization of overall survival between the ATG and control groups at 1- and 2-year post-HSCT and implies that earlier GVHD-associated mortality may be offset by later relapse mortality producing similar overall survival over time.

Impact of spliceosome mutation on outcomes of myelodysplastic syndrome and chronic myelomonocytic leukemia patients undergoing allogeneic hematopoietic cell transplantation

IntroductionAllogeneic Hematopoietic cell transplantation (allo-HCT) remains the only curative therapy for myelodysplastic syndrome (MDS) and chronic myelomonocytic leukemia (CMML). The impact of spliceosome mutations on allo-HCT outcome is unclear and further understanding is needed to assess the implications of this class of mutations on risk of relapse, overall survival (OS) and non-relapse mortality (NRM) in order to make decision regarding timing of allo-HCT. We examined the allo-HCT outcomes of MDS/CMML patients based on their spliceosome mutation profile to understand the impact of these mutations on transplant outcomes. ObjectiveTo compare outcomes of MDS/CMML patients with and without spliceosome mutations undergoing allo-HCT. MethodsThis is a single institution, retrospective study of MDS/CMML patients who underwent allo-HCT with myeloablative or reduced intensity conditioning (RIC) regimen at City of Hope from January 2016 to December 2021. Among them, patients who underwent molecular mutation profiling by NGS (Next Generation Sequencing) for a set of genes known to be mutated in myeloid neoplasms are included in this analysis. We compared OS, relapse free survival, NRM and acute/chronic graft versus host disease (GVHD) incidence between the spliceosome-mutated and unmutated groups. ResultsWe identified 258 consecutive MDS/CMML patients who underwent allo-HCT. Of these, 126 (48.8 %) patients had molecular profiling done among whom 57 (45.2 %) patients carried a spliceosome mutation. 84.9 % of patients had MDS and 55.6 % underwent a matched unrelated donor transplant. The median age for the whole cohort was 66 years (range 12–77).78.6 % and 73.7 % received RIC in the spliceosome and non-spliceosome groups, respectively. The 2-year OS for the whole cohort was 66.5 % (95 %CI 0.55–0.75) with a day 100 NRM of 7.1 % and 2-year cumulative incidence of relapse of 20 %. Grade II-IV acute GVHD at day 100 was 36.3 % (95 % CI 0.27–0.44) and any chronic GVHD at 2-years was 48.4 % (95 % CI 0.37–0.58). Patients who carried a spliceosome mutation had a significantly better 2-year survival of 83.8 % vs 55.9 % in the non-spliceosome group (P=0.002) and a better PFS of 73.7 % vs 50.0 % (P=0.007). There was no difference in the cumulative incidence of relapse at 2-years 15.9 % vs 18.5 % (P=0.59) between two groups but the spliceosome group had a significantly lower NRM at 2-years 10.4 % vs 31.5 % (P=0.009). There was no difference in incidence of acute or chronic GVHD between the two groups. ConclusionsAmong patients with MDS or CMML who underwent allo-HCT, our study shows better OS for patients who have spliceosome mutations due to lower NRM compared to those carrying non- spliceosome mutations. This favorable outcome of the spliceosome-mutated patients could have implications for timing of allo-HCT, particularly for patients in the intermediate MDS prognostic risk groups.

Unrelated donor transplantation with posttransplant cyclophosphamide vs ATG for myelodysplastic neoplasms

AbstractIt has been reported in prospective randomized trials that antithymocyte globulin (ATG)–based graft-versus-host disease (GVHD) prophylaxis has benefits in the setting of allogeneic hematopoietic stem cell transplantation (allo-HSCT) with unrelated donors (UDs). However, the optimal GVHD prophylaxis strategy has been challenged recently by the increasing use of posttransplant cyclophosphamide (PTCY). We report from the European Society for Blood and Marrow Transplantation registry the outcomes of 960 patients with myelodysplastic neoplasms who underwent allo-HSCT from UD with PTCY or ATG as GVHD prophylaxis. The primary outcomes were overall survival (OS) and progression-free survival (PFS). The disease characteristics were similar in both groups. Day 28 neutrophil engraftment was significantly better with ATG (93% vs 85%). Over a median follow-up of 4.4 years, the 5-year OS was 58% with PTCY, and 49% in the ATG group. The 5-year PFS was higher for PTCY at 53% vs 44% for ATG. Grade 2 to 4 acute GVHD incidence was lower when PTCY was used (23%), whereas there was no difference in the incidence of chronic GVHD at 5 years. Multivariable analyses confirmed better OS and PFS with PTCY with a hazard ratio (HR) for ATG of 1.32 (1-1.74) and a better PFS for PTCY with a HR for ATG of 1.33. This study suggests that GVHD prophylaxis using PTCY instead of ATG in this setting remains a valid option. Further prospective randomized studies would be essential to confirm these results.

Anti-T-lymphocyte globulin improves GvHD-free and relapse-free survival in myelofibrosis after matched related or unrelated donor transplantation

Acute and chronic graft-versus-host disease (GvHD) are major complications of allogeneic hematopoietic cell transplantation (alloHCT). In vivo T-cell depletion with anti-T-lymphocyte globulin (ATLG) as part of the conditioning regimen prior to alloHCT is frequently used as GvHD prophylaxis, but data on its role in myelofibrosis is scarce. We took advantage of an international collaborative network to investigate the impact of ATLG in myelofibrosis undergoing first alloHCT. We included 707 patients (n = 469 ATLG and n = 238 non-ATLG prophylaxis). The cumulative incidence of acute GvHD grade II-IV was 30% for the ATLG group vs. 56% for the non-ATLG group (P < 0.001). Acute GvHD grade III-IV occurred in 20% vs. 25%, respectively (P = 0.01). Incidence of mild-to-severe chronic GvHD was 49% vs. 50% (P = 0.52), while ATLG showed significantly lower rates of severe chronic GvHD (7% vs. 18%; P = 0.04). GvHD-free and relapse-free survival (GRFS) at 6 years was 45% for the ATLG group vs. 37% for the non-ATLG group (P = 0.02), driven by significantly improved GRFS of ATLG in matched related and matched unrelated donors. No significant differences in risk for relapse, non-relapse mortality, and overall survival were observed. Multivariable modeling for GRFS showed a 48% reduced risk of GvHD, relapse, or death when using ATLG.

Retrospective study to compare the outcomes of matched related donor vs matched unrelated donor in patient with acute myeloid leukaemia

BackgroundIndia's need for bone marrow donation and transplantation is increasing in the context of the rising incidence of haematological neoplasms like acute myeloid leukaemia (AML). The use of matched related donors (MRD) for hematopoietic stem cell transplantation (HSCT) is a feasible option, but the lack of HLA-matched donors in India remains a significant obstacle to successful treatment. MethodologyThis retrospective study was conducted at the Department of Hemato-Oncology & Bone Marrow Transplant, Rajiv Gandhi Cancer Institute in New Delhi, India over a period of 6 months. The study enrolled 77 AML MRD and 19 AML MUD patients based on the inclusion and exclusion criteria. ResultThe one-year survival rate was higher in MRD than in MUD, but there was no significant difference in mortality in multivariate analysis. The study also found that chronic graft-versus-host disease (GVHD) and relapse were associated with worse survival outcomes in both MRD and MUD HSCT. ConclusionThis study supports the use of matched unrelated donor (MUD) transplant for HSCT in AML patients when a matched sibling donor is not available.

A single-center retrospective study of salvage allogeneic hematopoietic stem cell transplantation pretreated with MeCBA regimen for refractory/relapsed acute myeloid leukemia

Thirty refractory relapsed acute myeloid leukemia (R/R AML) patients who received salvage allo-HSCT with MeCBA conditioning regimen from January 2018 to June 2022 at Henan Cancer Hospital were included, and their clinical data were reviewed. There were 16 males and 14 females among the 30 patients with a median age of 37 (16-53) years. There were 3 sibling allograft donor transplants, 1 unrelated donor transplant, and 26 haplotype transplants. The median course of pre-transplant chemotherapy was 4 (3-22). The time of neutrophil engraftment was 14 (9-22) days and 18 (10-40) days for platelet. The 30-day cumulative incidence of neutrophil engraftment was 100% and the 100-day cumulative incidence of platelet engraftment was 96.7% (95% CI 85.4% -97.5% ). 22 (73.3% ) patients experienced grade 1-2 gastrointestinal reactions, and there was no grade 3-4 organ toxicity. With a median follow-up of 37.1 months, the overall survival (OS) rate, event-free survival (EFS) rate, cumulative recurrence rate (CIR), and non-recurrence mortality (NRM) rate at 3 years after transplantation were 70.0% (95% CI 50.3% -83.1% ), 65.3% (95% CI 44.8% -79.8% ), 21.2% (95% CI 9.2% -44.4% ) and 16.7% (95% CI 7.3% -35.5% ), respectively.

High CD34-positive cell dose in matched unrelated donor allogeneic hematopoietic stem cell transplant is not associated with graft-versus-host disease or mortality.

CD34+ stem cells serve as the primary graft source for allogeneic transplants, with a minimum of 2-4 × 106 cells/kg needed for engraftment. There are conflicting data on outcomes at high stem cell doses, with studies limited by few patients receiving doses far above the minimum target. In this retrospective, single-center study of patients with hematologic malignancies who underwent matched unrelated donor transplants, we assessed outcomes for engraftment, survival, relapse, and graft-versus-host disease (GVHD) for the highest CD34+ dose quintile (>13 × 106 cells/kg, n = 36) compared to the remaining patients (n = 139). Similar analysis was performed correlating T cell dose and outcomes. There was no difference between the groups in neutrophil engraftment, with a trend toward faster platelet engraftment. There was no significant difference in mortality (adjusted risk ratio [aRR] = 1.02, 95% confidence interval [CI] = 0.85-1.22), relapse (aRR = 1.10, 95% CI = 0.85-1.42), or overall survival by Kaplan-Meier analysis (p = .44). High CD34+ dose was not associated with higher incidence of acute GVHD (aRR = 0.99 grades II-IV, aRR = 1.18 grades III-IV) or chronic GVHD (aRR = 0.87 overall, RR = 1.21 severe). There was limited correlation between CD34+ and T cell dose (R2 = .073), and there was no significant difference in survival, relapse, or GVHD in the highest T cell dose quintile (n = 33) compared to the remaining quintiles (n = 132). We found no difference in survival, relapse, or GVHD incidence or severity in patients receiving CD34+ doses above prior cutoffs reported in the literature. These data do not support the routine use of graft CD34+ dose reduction.

Long term results of a prospective multicenter observational study on the use of anti-human T-lymphocyte immunoglobulin (ATLG) in unrelated donor transplantation (ATOS study)

ATOS is a prospective observational study evaluating the outcome of patients receiving anti-human T-lymphocyte immunoglobulin (ATLG) in unrelated donor transplantation. Primary endpoint was severe GvHD and relapse-free survival (SGRFS). GvHD prophylaxis consisted of ATLG and CSA/ MTX or MMF. Outcome was compared to the ATLG arm of our prospective randomized phase III multicenter trial trial (RCT) [1, 2]. 165 patients, median age 54 (18; 77) years, with haematological malignancies with early (45.5%), intermediate (17.6%), and advanced (37.0%) disease were included. ATLG dose differed between centers according to local practise (median total ATLG dose of 46 (IQR 32–60, range 15–91) mg/kg). Median follow-up was 70 months. Estimated probabilities at 5 years follow up were for SGRFS 0.27, OS 0.52, DFS 0.43, NRM 0.23, relapse 0.34, acute GvhD °III/IV 0.13, severe chronic GvHD 0.27. OS rates differed dependent on disease status. An effect of the given ATLG dose could not be separated from potential center effects. Despite higher age and more advanced disease in ATOS, outcome was similar to the ATLG arm of our RCT. This long-term, multicenter, experience in routine clinical practice confirms the GvHD-protective effect of ATLG without compromising relapse and non-relapse mortality rates.Clinical Trial Registry: German clinical trials register DRKS00004581.

Haploidentical donor peripheral blood stem cell transplantation using third-party cord blood compared with matched unrelated donor transplantation for patients with hematologic malignancies

Objectives: To assess the efficacy of cord blood-assisted haploid peripheral blood stem cell transplantation (haplo-cord-PBSCT) versus unrelated donor peripheral blood stem cell transplantation (UD-PBSCT) in the treatment of malignant hematological diseases. Methods: A retrospective analysis was performed on one hundred and four patients with malignant hematological diseases who underwent haplo-cord-PBSCT and fifty-two patients who underwent UD-PBSCT at Xiangya Hospital of Central South University between January 2016 and December 2021. Results: ①The median implantation time for neutrophils in the haplo-cord-PBSCT and UD-PBSCT groups was 13 (9-22) days and 13 (10-24) days, respectively (P=0.834), whereas the median implantation time for platelets was 15 (7-103) days and 14 (8-38) days, respectively (P=0.816). The cumulative implantation rate of neutrophils at 30 days after transplantation in the haplo-cord-PBSCT group and the UD-PBSCT group was 100% (P=0.314), and the cumulative platelet implantation rate at 100 days after transplantation was 95.2% (95% CI 88.3% - 98.1% ) and 100% (P=0.927), respectively. 30 days after transplantation, both groups of patients achieved complete donor chimerism, and no umbilical cord blood stem cells were implanted. ②The cumulative incidence rates of grade Ⅱ-Ⅳ acute GVHD within 100 days after transplantation in the haplo-cord-PBSCT group and the UD-PBSCT group were 29.1% (95% CI 20.1% -38.1% ) and 28.8% (95% CI 17.2% -41.6% (P=0.965), respectively. The cumulative incidence rates of grade Ⅲ/Ⅳ acute GVHD were 7.8% (95% CI 3.6% -14.0% ) and 9.6% (95% CI 3.5% -19.5% ) (P=0.725). The cumulative incidence rates of 2-year chronic GVHD in the haplo-cord-PBSCT group and the UD-PBSCT group were 45.3% (95% CI 36.1% -56.1% ) and 35.1% (95% CI 21.6% -44.1% ), respectively (P=0.237). The cumulative incidence rates of severe chronic GVHD at 2 years after transplantation were 13.6% (95% CI 7.6% -21.3% ) and 12.9% (95% CI 5.1% -24.3% ), respectively (P=0.840). ③The 2-year CIR after transplantation in the haplo-cord-PBSCT group and UD-PBSCT group were 12.8% (95% CI 7.0% -20.5% ) and 10.0% (95% CI 3.6% -20.2% ), respectively (P=0.341), and the NRM were 14.7% (95% CI 8.4% -22.6% ) and 16.2% (95% CI 7.4% -28.0% ), respectively (P=0.681). ④The 2-year OS rates in the haplo-cord-PBSCT and UD-PBSCT groups after transplantation were 82.2% (95% CI 74.8% -90.3% ) and 75.5% (95% CI 64.2% -88.7% ), respectively (P=0.276). The 2-year DFS rates were 69.9% (95% CI 61.2% -79.8% ) and 73.8% (95% CI 62.4% -87.3% ), respectively (P=0.551). The 2-year rates of GVHD-free/recurrence-free survival (GRFS) were 55.3% (95% CI 44.8% -64.8% ) and 64.7% (95% CI 52.8% -79.3% ), respectively (P=0.284) . Conclusion: The findings of this study indicate that haplo-cord-PBSCT and UD-PBSCT have comparable efficacy and safety in the treatment of malignant hematological diseases and can be used as an alternative treatment options.

Allogenic hematopoietic stem cell transplantation outcomes of patients aged ≥ 55 years with acute myeloid leukemia or myelodysplastic syndromes in China: a retrospective study

BackgroundElderly patients with acute myeloid leukemia or myelodysplastic syndromes (AML/MDS) have historically had poor prognoses. However, there has been a recent increase in the use of allogenic hematopoietic stem cell transplantation (allo-HSCT) are in this patient population. Nevertheless, the optimal choice of donor type for the patients remains an unmet need. Limited data exist on the use of allo-HSCT in elderly patients with AML/MDS from China. To better understand and optimize the selection of donor type for the elderly patients, particularly for those with refractory or relapsed disease, in comparison with the previous studies in the US and Europe.MethodsOur retrospective study enrolled 259 patients aged over 55 years who underwent their first allo-HSCT between April 2015 and August 2022. These patients were divided into three groups based on donor type: haploidentical related donor group (haploidentical related donor transplantation [HID], n = 184), matched sibling donor group (matched sibling donor transplantation [MSD], n = 39), and matched unrelated donor group (matched unrelated donor transplantation [MUD], n = 36). Statistics were performed with the chi-square test, the log-rank and Fine-Gray tests.ResultsThe median age of the cohort was 57 years (range: 55–75) and 26.25% of patients were over 60 years old. Younger patients had a higher incidence of acute graft-versus-host disease (HR = 1.942, P = 0.035), faster neutrophil recovery (HR = 1.387, P = 0.012), and better overall survival (HR = 0.567, P = 0.043) than patients aged ≥ 60 years across the entire cohort. Patients with refractory or relapsed (R/R) diseases had delayed neutrophil engraftment (P = 0.010, HR = 0.752) and platelet engraftment (P < 0.001, HR = 0.596), higher incidence of relapses (HR = 2.300, P = 0.013), and inferior relapse-free survival (RFS) (HR = 1.740, HR = 0.016) regardless of donor type. When it came to graft-versus-host-disease-free, relapse-free survival (GRFS), MUDs turned out to be superior to HIDs (HR = 0.472, P = 0.026) according to the multivariable analysis. In contrast, we found MSDs had an inferior GRFS to HIDs in parallel (HR = 1.621, P = 0.043).ConclusionThe choice of donor type did not significantly affect the outcomes of allo-HSCT. However, when considering the quality of post-transplant life, MUDs or HIDs from younger donors may be the optimal choice for elderly patients.

Individualized dose of anti-thymocyte globulin based on weight and pre-transplantation lymphocyte counts in pediatric patients: a single center experience.

Anti-thymocyte globulin (ATG) has become a standard in preventing GVHD in related and unrelated donor transplantation, but there is no consensus on the best administration schedule. The PARACHUTE trial reported excellent CD4 immune reconstitution (CD4 IR) using a dosing schedule based on the patient's weight and pre-conditioning absolute lymphocyte count (ALC). In 2015 we introduced the PARACHUTE dosing schedule for pediatric patients at our center. One hundred one patients were transplanted for malignant and non-malignant diseases. In this non-concurrent cohort CD4 IR+, defined by a single CD4 count >50/µL on day 90, was seen in 81% of patients. The incidence of grade II-IV and III to IV aGvHD was 26.6% and 15.3% and 5% for cGvHD with no severe cases. We found no difference in aGvHD between donor type and stem cell sources. Five-year EFS and OS were 77.5% and 83.5%. Grade III-IV GFRS was 75.2%. CD4 IR+ patients had better EFS (93.1% vs. 77.7%, p = 0.04) and lower non-relapse mortality (2.7% vs. 22.2%, p = 0.002). The PARACHUTE ATG dosing schedule individualized by weight and ALC results in good early immune reconstitution, low incidence of cGvHD, and favorable survival for patients with different disease groups, donor types, and stem cell sources.

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.