Sibling Donor Hematopoietic Stem Cell Research Articles

Azathioprine/hydroxyurea preconditioning prior to nonmyeloablative matched sibling donor hematopoietic stem cell transplantation in adults with sickle cell disease: A prospective observational cohort study.

Nonmyeloablative, matched sibling donor hematopoietic stem cell transplantation with alemtuzumab/total body irradiation (TBI) conditioning is a curative therapy with low toxicity for adults with sickle cell disease (SCD). However, relatively low donor chimerism levels and graft rejection remain important challenges. We hypothesized that adding azathioprine/hydroxyurea preconditioning will improve donor chimerism levels and reduce graft failure rate. In this prospective cohort study, we enrolled consecutive adult patients with SCD undergoing matched sibling donor transplantation at the Amsterdam UMC. Patients received azathioprine 150 mg/day and hydroxyurea 25 mg/kg/day for 3 months prior to alemtuzumab 1 mg/kg and 300 cGy TBI conditioning. Twenty patients with SCD (median age 26 years [range 19-49], 13 females) were transplanted. Median follow-up was 46.0 months (IQR 21.8-57.9). One-year overall survival and event-free survival (graft failure or death) were both 95% (95% confidence interval 86-100). Mean donor myeloid and T-cell chimerism 1-year post-transplant were 95.2% (SD ±10.6) and 67.3% (±15.3), respectively. One patient (5%) experienced graft failure without autologous regeneration, resulting in infections and death. All other patients had a corrected SCD phenotype and were able to discontinue sirolimus. Three patients were successfully treated with alemtuzumab (1 mg/kg) after the transplant because of declining donor chimerism and cytopenias to revert impending graft rejection. Toxicity was mostly related to sirolimus and alemtuzumab. One patient developed steroid-responsive grade II intestinal acute graft-versus-host disease. Collectively, preconditioning with azathioprine/hydroxyurea prior to nonmyeloablative matched sibling donor transplantation resulted in excellent event-free survival and robust donor T-cell chimerism, enabling the successful withdrawal of sirolimus. ClinicalTrials.gov: NCT05249452.

Outcome and late effects of matched related peripheral-blood stem-cell transplantation in children with severe aplastic anemia

Background Aplastic Anemia (AA) is a life- threatening disease. Cure can be achieved in a large proportion of patients with prompt treatment with matched sibling donor Hematopoietic Stem Cell Transplantation (HSCT) as first line therapy. Aim Study of the outcomes and late effects among children with severe aplastic anemia after receiving matched related peripheral-blood stem-cell (PBSC) transplantation and cyclophosphamide/antithymocyte globulin conditioning regimen at Ain Shams University Pediatric Bone Marrow Transplantation Unit, Cairo, Egypt. Methods Data of 15 patients with severe aplastic anemia who received matched related PBSC transplantation between January 2011 and December 2018 were analysed retrospectively. All long-term survivors were followed up for 2 years. Follow up studies included detailed assessment of growth, graft evaluation, immune reconstitution, long-term effects on the liver, kidney, pulmonary, cardiac, endocrine functions, chronic graft-versus-host disease (GVHD), and infectious complications. Results The median duration of the study was 87 months (43–115 months). The overall survival was 73.3%. Event-free survival was 66.7%. All mortality was within 2 months posttransplant. Blood counts were within normal limits. Chimerism was complete for all except one. Growth assessment revealed Z score of weight, height, and BMI 0 (−1.8–1.6), −0.7 (−1.8–0.95), and 0.34 (−1.29–2). Abnormal thyroid function was found in three (27%) patients. No documented high-grade acute GVHD or extensive chronic GVHD. Cardiac, pulmonary, hepatic, and renal functions showed no abnormality. Immune reconstitution was consistent, and no malignant complications were reported. Conclusion This study confirmed the feasibility and safety of matched related PBSC transplantation in the pediatric population in low-income countries. Overall survival and event-free survival were satisfactory.

Basiliximab Treatment for Patients With Steroid-Refractory Acute Graft-Versus-Host Disease Following Matched Sibling Donor Hematopoietic Stem Cell Transplantation.

Basiliximab is an important treatment for steroid-refractory acute graft-versus-host disease (SR-aGVHD). We performed this retrospective study to evaluate the efficacy and safety of basiliximab treatment in SR-aGVHD patients following matched sibling donor hematopoietic stem cell transplantation (MSD-HSCT) (n = 63). Overall response rate (ORR) was 63.5% and 54% at any time and at day 28 after basiliximab treatment. Grade III-IV aGVHD before basiliximab treatment predicted a poor ORR after basiliximab treatment. The rates of virus, bacteria, and fungi infections were 54%, 23.8%, and 3.1%, respectively. With a median follow-up of 730 (range, 67-3,042) days, the 1-year probability of overall survival and disease-free survival after basiliximab treatment were 58.6% (95% confidence interval [CI] = 47.6%-72.2%) and 55.4% (95% CI = 44.3%-69.2%), respectively. The 3-year cumulative incidence of relapse and non-relapse mortality after basiliximab treatment were 18.9% (95% CI = 8.3%-29.5%) and 33.8% (95% CI = 21.8%-45.7%), respectively. Comorbidities burden before allo-HSCT, severity of aGVHD and liver aGVHD before basiliximab treatment showed negative influences on survival. Thus, basiliximab was safe and effective treatment for SR-aGVHD following MSD-HSCT.

The range of haploidentical transplant protocols in sickle cell disease: all haplos are not created equally.

The ideal curative therapy for sickle cell disease (SCD) must be applicable across all ages and include individuals with strokes and preexisting heart, lung, and kidney disease. Myeloablative, matched sibling donor hematopoietic stem cell transplant (HCT) for children with SCD has shown excellent outcomes over the past 3 decades but has been restricted due to the limited availability of a human leukocyte antigen-matched sibling donor (10%-15%) and increased treatment-related death in adults with myeloablative conditioning. To overcome these 2 significant barriers to curative therapy in SCD, related haploidentical HCT has become an active area of research. The use of related haploidentical donors (first- and second-degree relatives) increases the donor pool to at least 90% of those eligible across the life span. Importantly, most adults, even with strokes or significant comorbidities, can tolerate the nonmyeloablative conditioning regimen without treatment-related death. Since 2013, at least 3 related haploidentical HCT strategies have emerged as potential curative therapies for SCD: (1) a nonmyeloablative, T-cell replete, bone marrow transplant with thiotepa and posttransplant cyclophosphamide with a goal of complete donor chimerism; (2) a nonmyeloablative, in vivo T-cell depletion, using peripheral blood stem cells (PBSCs) with a goal of stable mixed donor-recipient chimerism; and (3) a myeloablative, ex vivo T-cell depletion using PBSCs and advanced-technology graft manipulation, with a goal of complete donor chimerism. We review the similarities, differences, outcomes, and gaps in knowledge with these 3 haploidentical HCT approaches for SCD.

Bone Marrow Versus Peripheral Blood in HLA-Matched Sibling Transplantation: Does the Stem Cell Source Matter in Severe Aplastic Anemia?

Background Selecting a graft source is critical in HLA-matched sibling donor hematopoietic stem cell transplantation (MSD-HCT) for severe aplastic anemia (SAA). Since graft-versus-host-disease (GVHD) is the major cause of mortality after MSD-HCT, and SAA patients do not need the graft-versus-leukemia effect, the selection of a suitable source of stem cells becomes critical. Although bone marrow (BM) is the preferable stem cell source based on the registry-based studies, mobilized peripheral blood stem cells (PBSC) may offer faster engraftment with rapid immune reconstitution. Moreover, the recent advances in conditioning regimens have significantly reduced transplantation-related complications. Here, we compared the long-term outcomes of BM vs PBSC as a graft source in adult patients with SAA who received MSD-HCT with the reduced intensity conditioning (RIC) regimen. Method We conducted a retrospective analysis of 171 consecutive SAA adult patients who received MSD-HCT with Flu6/Cy2/ATG4 RIC regimen (Flu, 30 mg/m 2 IV for 6 days: Cy, 50 mg/kg IV for 2 days; rabbit ATG, 2.5 mg/kg IV for 4 days) or total nodal irradiation (TNI) of 750 cGy combined with ATG as GVHD prophylaxis (TNI-750/ATG) from March 2002 to March 2021 at Seoul St. Mary's Hospital, Seoul, Korea. BM was the primary graft source, but PBSC was used in donors who refused BM harvest, were unsuitable for general anesthesia, or received TNI-750/ATG conditioning. The primary endpoint of this study was to compare the overall survival (OS), and the secondary endpoints included speed of hematologic recovery, primary or secondary graft failure (GF), and failure-free survival (FFS) between the BM and PBSC group. Results The median patient age in the BM group was 38 years (range, 15 - 59) and 44 years (range, 19 - 64) in the PBSC group (p=0.005). There were no differences of baseline characteristics between the two groups except for a donor-to-recipient sex discrepancy (female to male, BM vs. PBSC; 16.4% vs. 30.9%, p=0.029). The majority of BM group (114/116, 98.2%) received the Flu6/Cy2/ATG4 RIC regimen, while 38.2% (21/55) of PBSC group received TNI-750/ATG for the conditioning (p<0.001). The PBSC contained a median 4.71 (range, 1.22 - 17.03) x 10 6/kg CD34 + cells and 368.82 (range, 25.12 - 1234.70) x 10 6/kg CD3 + cells which were about 1.7-fold (BM 2.80 x 10 6/kg CD34 + cells; range, 0.25 - 10.05) and 10-fold (BM 39.61 x 10 6/kg CD3 + cells; range, 1.34 - 463.68) higher than the BM graft (p<0.001). Consequently, the PBSC group exhibited faster engraftment of neutrophils (median 13 vs. 11 days, p<0.001) and platelets (median 18 vs. 12 days, p=0.012). However, there were no differences in the incidence of secondary GF (19.0% vs. 12.7%, p=0.386) and donor-type aplasia (4.3% vs. 10.9%, p=0.178) between two groups. Furthermore, the incidence of acute grade I-II (8.6% vs. 10.9%, p=0.619) and moderate to severe chronic graft-versus-host disease (GVHD) (3.5% vs. 5.5%, p=0.542) were also not significantly different between two groups. However, the BM group has shown more CMV reactivation (44.0% vs. 24.9%, p=0.005), and higher incidence of respiratory infection (14.7% vs. 3.6%, p=0.037) than those of the PBSC group. The incidences of transplantation-related complications between the BM and PBSC group are summarized in Table. The 10-year OS (93.8% vs. 98.1%, p=0.246) and FFS (65.7% vs. 69.0%, p=0.455) were comparable (Figure). Moreover, there was no significant difference in FFS between BM and PBSC group by potential risk factors of patient and donor age at MSD-HCT, sex incompatibility, ABC mismatch, PNH clone presence, HCT-CI ≥3, infused CD34 + cell count, interval from diagnosis to transplant, prior IST history, heavy transfusion before allo-HCT, or severity of AA. Conclusions Our results suggest that survival outcomes of MSD-HCT showed no difference between BM and PBSC as graft sources, and using PBSC may be an efficient alternative offering faster engraftment without significant difference in graft failure or transplantation-related adverse events such as GVHD, and survival. Current analysis and results were drawn from the Asian population with a fludarabine-based conditioning regimen and therefore, need to validate in the Western population. In addition, well-designed prospective studies in a larger cohort are required to confirm our findings.

Efficacy analysis of anti-thymocyte globulin regimens with different timing strategies for matched sibling donor hematopoietic stem cell transplantation

Objective: To compare the effects of two administration time strategies for rabbit antihuman thymocyte immunoglobulin (rATG) of 5mg/kg total dose in matched sibling donor hematopoietic stem cell transplantation (MSD-HSCT) . Methods: This study retrospectively analyzed the clinical data of 32 patients who received MSD-HSCT with 5 mg/kg rATG conditioning regimen at the Department of Hematology of the First Medical Center of the People's Liberation Army General Hospital from October 2020 to April 2022. The patients were classified into two groups: the 4d-rATG group (16 cases), who received antithymocyte globulin (ATG) from day -5 to day -2, and the 2d-rATG group (16 cases), who received ATG from day -5 to day -4. Between the two groups, the transplantation outcomes, serum concentrations of active antithymocyte globulin (ATG) in patients from -4 days to 28 days after graft infusion (+28 days), and the reconstitution of lymphocyte subsets on days +30, +60, and +90 were compared. Results: The cumulative incidences of acute graft-versus-host disease at 100 days after graft infusion were 25.0% (95% CI 7.8% -47.2% ) and 18.8% (95% CI 4.6% -40.2% ) (P=0.605) in the 4d-rATG group and 2d-rATG group, respectively. The 1-year cumulative incidences of chronic graft-versus-host disease were 25.9% (95% CI 8.0% -48.6% ) and 21.8% (95% CI 5.2% -45.7% ) (P=0.896). The 1-year cumulative incidence of relapse was 37.5% (95% CI 18.9% -65.1% ) and 14.6% (95% CI 3.6% -46.0% ) (P=0.135), and the 1-year probabilities of overall survival were 75.0% (95% CI 46.3% -89.8% ) and 100% (P=0.062). The total area under the curve (AUC) of serum active ATG was 36.11 UE/ml·d and 35.89 UE/ml·d in the 4d-rATG and 2d-rATG groups, respectively (P=0.984). The AUC was higher in the 4d-rATG group than that in the 2d-rATG group (20.76 UE/ml·d vs 15.95 UE/ml·d, P=0.047). Three months after graft infusion, the average absolute count of CD8(+) T lymphocytes in the 4d-rATG group was lower than that in the 2d-rATG group (623 cells/μl vs 852 cells/μl, P=0.037) . Conclusion: The efficiencies of GVHD prophylaxis in MSD-PBSCT receiving 4d-ATG regimen and the 2d-rATG regimen were found to be similar. The reconstruction of CD8(+)T lymphocytes in the 2d-rATG group was better than that in the 4d-rATG group, which is related to the lower AUC of active ATG after transplantation.

Application prospect of low-dose porcine anti-thymocyte globulin in HLA-matched sibling donor transplantation

ABSTRACTObjectiveTo investigate the preventive effect of low-dose porcine anti-thymocyte globulin (P-ATG) on graft versus host disease (GVHD) in patients' donors over 40 years old or female donors undergoing HLA-matched sibling donor hematopoietic stem cell transplantation (MSD-HSCT).MethodsThe clinical data of 30 patients received Low-dose Porcine antithymocyte globulin (P-ATG) as a part of the conditioning regimen (the P-ATG group), while the other 30 patients didn’t receive ATG (the Non-ATG group).ResultsThere was a significant difference in the incidence of aGVHD ([23.3 (10.1–39.7) %] vs [50.0 (30.8–66.5) %], P = 0.028), grade II–IV aGVHD ([16.7 (5.94–32.1) %] vs [40.0 (22.4–57.0) %], P = 0.049) and chronic GVHD (cGVHD) ([22.4 (6.03–45.1) %] vs [69.0 (43.4–84.8) %], P = 0.001) between two groups. But there was no significant difference in terms of moderate-severe cGVHD (P = 0.129), 1-year relapse rate (P = 0.742), non-relapse mortality (P = 0.237), or overall survival (P = 0.441).ConclusionThe application of low-dose P-ATG in patients/donors over 40 years old or female donors undergoing MSD-HSCT for hematological malignancy can significantly reduce the incidence of aGVHD, grade II–IV aGVHD and cGVHD, doesn’t increase the risk of relapse.

561 - Incidence and Outcome of Secondary Graft Failure in Matched Sibling Donor Hematopoietic Stem Cell Transplantation for Severe Aplastic Anemia: A Single Center Study

561 - Incidence and Outcome of Secondary Graft Failure in Matched Sibling Donor Hematopoietic Stem Cell Transplantation for Severe Aplastic Anemia: A Single Center Study

Combination of Cytogenetic Classification and MRD Status Correlates with Outcomes of Autologous Versus Allogeneic Stem Cell Transplantation in Adults with B Cell-Acute Lymphoblastic Leukemia in First Remission

Objectives: To analyze overall survival (OS), leukemia-free survival (LFS), cumulative incidence of relapse (CIR) and non-relapse mortality (NRM) of patients with B cell-acute lymphoblastic leukemia (B-ALL) who received autologous or allogeneic stem cell transplantation and to provide the basis for the choice of transplantation method. Methods: We retrospectively investigated the outcomes of 388 adult patients with B-ALL in our center. The OS, LFS, CIR and NRM rate and the impact of minimal residual disease (MRD) within 3 chemotherapy cycles along with risk classification were explored. Results: Both univariate and multivariate analysis found that negative MRD within 3 chemotherapy cycles was the important factor associated with the prognosis. As to 355 patients who obtained first complete remission (CR1), we divided patients into 3 groups according to the risk stratification and MRD status within 3 chemotherapy cycles. For patients with negative MRD within 3 chemotherapy cycles and standard-risk group, the 3-year OS (82.5% vs 74.1%, P=0.364), LFS (74.5% vs 74.1%, P=0.904), CIR (25.5% vs 17.6%, P=0.648) and NRM rates(0% vs 8.3%, P=0.234) were not significantly different between autologous hematopoietic stem cell transplantation (auto-HSCT) and allogeneic hematopoietic stem cell transplantation (allo-HSCT) group（Figure 1）. In patients with negative MRD and high-risk factors, although auto-HSCT group and allo-HSCT group had similar 3-year OS(72.7% vs 68.5%, P=0.436) and LFS rate (62.8% vs 56.0%, P=0.375) , the lower NRM (1.5% vs 25.1%, P=0.000) was offset by higher CIR(35.7% vs 18.9%, P=0.018) in auto-HSCT group compared with allo-HSCT group（Figure 2）. As for other patients with high-risk factors and positive MRD after 3 chemotherapy cycles, the prognosis of auto-HSCT group was evidently worse than those of allo-HSCT group as there was a lower trend of 3-year OS (50.0% vs 66.0%, P=0.077), LFS rate (30.8% vs 47.1%, P=0.398) and significantly higher CIR rate(71.4% vs 39.1%, P=0.018) in auto-HSCT group compared to allo-HSCT group（Figure 3）. MRD within 3 chemotherapy cycles was also related to the selection of allogeneic transplantation methods and pretreatment schemes. The 3-year OS (67.4% vs 60.8% vs 65.2%, p=0.735), LFS (56.3% vs 48.3% vs 58.3%, P=0.538), CIR (21.7% vs 23.3% vs 13.3%, P=0.784) and NRM rate (22.1% vs 28.4% vs 28.3%, P=0.672) were similar in matched sibling donor hematopoietic stem cell transplantation (MSD-HSCT), haploid hematopoietic stem cell transplantation (haplo-HSCT) and unrelated donor hematopoietic stem cell transplantation (URD-HSCT) group patients who achieved negative MRD within 3 chemotherapy cycles. While MSD-HSCT group tended to have lower 3-year LFS (33.0% vs 54.1% vs 41.7%, P=0.198) and higher CIR rate (53.2% vs 33.7% vs 46.2%, P=0.233) when comparing with haplo-HSCT and URD-HSCT group patients whose MRD were still positive within 3 chemotherapy cycles. Moreover, in patients who achieved negative MRD within 3 chemotherapy cycles, there was no significant difference in 3-year CIR rate (24.5% vs 23.1%, P=0.784) between TBI group and non-TBI group, but the lower OS (64.2% vs 76.3%, P=0.027) and LFS (54.4% vs 71.3%, P=0.091) was mainly due to the higher NRM rate (17.8% vs 5.6%, P=0.062) in TBI group. For MRD positive patients, TBI group had advantages over non-TBI group, demonstrating a trend of higher 3-year OS (65.0% vs 42.9%, P=0.105), LFS (44.8% vs 27.1%, P=0.138), lower CIR (43.6% vs 63.8%, P=0.106) and similar NRM rate (11.7% vs 9.1%, P=0.671). In addition, we found that 8 most frequently mutated genes were KMT2D、FAT1、NRAS、PAX5、KRAS、SETD2、ASXL1、PTPN11 in 175 patients with preliminary second generation sequencing results（Figure 4）. Mutations in CARD11 and NOTCH signaling pathway were correlated with lower LFS (CARD11: 56.3% vs 16.7%, P=0.002; NOTCH signaling pathway: 59.2% vs 38.8%, P=0.049)（Figure 5）. Conclusions: Auto-HSCT with maintenance therapy after HSCT and non-TBI pretreatment schemes appears to be an attractive treatment option for patients with B-ALL especially for those who achieved negative MRD within 3 chemotherapy cycles. For MRD positive patients, allogeneic transplantation and TBI pretreatment schemes may be more effective. Key words: auto-HSCT, allo-HSCT, acute lymphoblastic leukemia, minimal residual disease Figure 1View largeDownload PPTFigure 1View largeDownload PPT Close modal

Post-Transplant Cyclophosphamide after Matched Sibling and Unrelated Donor Hematopoietic Stem Cell Transplantation in Pediatric Patients with Acute Myeloid Leukemia.

Non-relapse mortality due to GVHD and infections represents a major source of morbidity and mortality in pediatric HSCT recipients. Post-transplant cyclophosphamide (PTCy) has emerged as an effective and safe GVHD prophylaxis strategy, with improved GVHD and relapse-free survival in matched (related and unrelated) and mismatched haploidentical HSCT adult recipients. However, there are no published data in pediatric patients with acute myeloid leukemia who received matched-donor HSCT with PTCy. We demonstrate, in this case series, that the use of PTCy in this population is potentially safe, effective in preventing acute GVHD, does not impair engraftment, is associated with reduced non-relapse mortality, and does not hinder immune reconstitution post HSCT.

Frontline Therapy Options for Adults With Newly Diagnosed Severe Aplastic Anemia: Intensive immunosuppressive Therapy Plus Eltrombopag or Matched Sibling Donor Hematopoietic Stem Cell Transplantation?

Severe aplastic anemia (SAA) is a life-threatening bone marrow failure disease. Allogeneic hematopoietic stem cell transplantation from a matched sibling donor (MSD-HSCT) and intensive immunosuppressive therapy (IST) are 2 major comparable treatments for SAA. As the addition of eltrombopag (EPAG) to standard IST therapy has greatly improved the survival prognosis of SAA, whether MSD-HSCT or IST/EPAG is the better choice has become a matter of debate. A study was performed involving 99 patients with newly diagnosed acquired SAA from 5 medical centers, including 48 MSD-HSCT cases and 51 IST/EPAG cases, which consisted of rabbit antithymocyte globulin or porcine-antilymphocyte globulin, cyclosporine plus eltrombopag. The results suggested that patients treated with MSD-HSCT or IST/EPAG had similar overall survival (OS) rates exceeding 95% (P = .97). However, the event-free survival rate (EFS) of IST/EPAG (71.0%) was significantly lower than that of MSD-HSCT (89.6%), P = .04. Subgroup analysis indicated that the OS of the MSD-HSCT group was superior to that of the IST/EPAG group (100% versus 85.7%, P = .04) among those with very severe aplastic anemia (VSAA). Both the complete response rate (CR) and overall response rate (OR) with MSD-HSCT were significantly higher than those with IST/EPAG (CR: 79.2% versus 15.7%, P < .001; OR: 97.9% versus 72.6%, P = .001). In conclusion, IST/EPAG or MSD-HSCT treatment achieves an equally high OS in SAA, but MSD-HSCT leads to a better OS in patients with VSAA and shows advantages in improving EFS and accelerating hematopoietic reconstruction in patients with SAA.

A retrospective comparative study of haplotype hematopoietic stem cell transplantation and human leukocyte antigen-matched sibling donor hematopoietic stem cell transplantation in the treatment of acute B-lymphocyte leukemia

目的探讨单倍型造血干细胞移植（haplo-HSCT）治疗移植前微小残留病（Pre-MRD）阳性急性B淋巴细胞白血病（B-ALL）是否较全相合同胞造血干细胞移植（MSDT）具有生存优势，以及该作用是否受Pre-MRD的影响。方法对2009年6月至2018年6月在北京大学血液病研究所接受异基因造血干细胞移植（allo-HSCT）的998例移植前处于完全缓解（CR）的B-ALL患者进行回顾性分析，其中haplo-HSCT组788例、MSDT组210例，移植前用多参数流式细胞术（MFC）检测MRD水平。结果①全部998例B-ALL患者中，997例获得持续的完全供者嵌合状态，移植后100 d中性粒细胞、血小板植入率分别为99.9％（997/998）、95.3％（951/998），Ⅱ～Ⅳ度急性移植物抗宿主病（GVHD）发生率为26.6％（95％CI 23.8％～29.4％），3年慢性GVHD累积发生率为49.1％（95％CI 45.7％～52.4％），移植后3年白血病累积复发率（CIR）为17.3％（95％CI 15.0％～19.7％），非复发死亡率（NRM）为13.8％（95％ CI 11.6％～16.0％），移植后3年无白血病生存（LFS）率、总生存（OS）率分别为69.1％（95％CI 66.1％～72.1％）、73.0％（95％CI 70.2％～75.8％）。②Pre-MRD阳性组（282例）患者移植后3年CIR高于Pre-MRD阴性组（716例）［31.6％（95％CI 25.8％～37.5％）对14.3％（95％CI 11.4％～17.2％），P<0.001］。③在Pre-MRD阳性组中，haplo-HSCT患者（219例）移植后3年CIR低于MSDT患者（63例）［27.2％（95％CI 21.0％～33.4％）对47.0％（95％CI 33.8％～60.2％），P＝0.002］。④全部998例患者按照Pre-MRD结果分为阴性组（716例）、<0.01％组（46例）、0.01％～<0.1％组（117组）、0.1％～<1％组（87例）、≥1％组（32例）；5组患者中，<0.01％组haplo-HSCT患者（40例）移植后3年CIR低于MSDT患者（6例）［10.0％（95％CI 0.4％～19.6％）对32.3％（95％CI 0％～69.9％），P＝0.017］，0.01％～<0.1％组haplo-HSCT患者（81例）移植后3年CIR也低于MSDT患者（36例）［20.4％（95％CI 10.4％～30.4％）对47.0％（95％CI 29.2％～64.8％），P＝0.004］；其他三组中，haplo-HSCT和MSDT患者移植后3年CIR差异无统计学意义。⑤在Pre-MRD<0.1％组（163例）中，haplo-HSCT患者（121例）移植后3年CIR低于MSDT患者（42例）［16.0％（95％CI 9.4％～22.7％）对40.5％（95％ CI 25.2％～55.8％），P<0.001］，3年LFS率、OS率均高于MSDT组［78.2％（95％CI 70.6％～85.8％）对47.6％（95％CI 32.2％～63.0％），P<0.001；80.5％（95％CI 73.1％～87.9％）对54.6％（95％CI 39.2％～70.0％），P<0.001］，两组3年NRM差异无统计学意义［5.8％（95％CI 1.6％～10.0％）对11.9％（95％CI 2.0％～21.8％），P＝0.188］。多因素分析显示，haplo-HSCT是Pre-MRD<0.1％组移植后低CIR（HR＝0.248，95％CI 0.131～0.472，P<0.001）、高LFS率（HR＝0.275，95％CI 0.157～0.483，P<0.001）和高OS率（HR＝0.286，95％CI 0.159～0.513，P<0.001）的独立影响因素。结论haplo-HSCT治疗Pre-MRD<0.1％的B-ALL患者较MSDT具有生存优势。

Haploidentical Versus Matched Sibling Donor Hematopoietic Stem Cell Transplantation for Adult Patients with Relapsed/Refractory Acute Lymphoblastic Leukemia: A Study from the Acute Leukemia Working Party of the European Society for Blood and Marrow Transplantation

Haploidentical Versus Matched Sibling Donor Hematopoietic Stem Cell Transplantation for Adult Patients with Relapsed/Refractory Acute Lymphoblastic Leukemia: A Study from the Acute Leukemia Working Party of the European Society for Blood and Marrow Transplantation

Comparable Outcome of CD3+-/CD19+ Depleted Haploidentical with Matched Sibling Donor Hematopoietic Stem Cell Transplantation for Advanced Stage Sickle Cell Disease: Result of a Pilot Study

IntroductionSickle cell disease (SCD) is an inherited disorder with an estimate of 300.000 affected newborns per year worldwide. Despite significant improvements in preventive measures, supportive care and conventional therapy, substantial morbidity and mortality with a reduced life expectancy persists. Allogeneic hematopoietic stem cell transplantation (HSCT) with a matched sibling donor (MSD) is currently the curative standard of care for SCD patients (pts). But MSD and unrelated matched donor availability is <20% and graft- versus-host disease (GvHD) remains to be associated with significant morbidity and mortality with T cell repleted grafts and standard GvHD prophylaxis, which is unacceptable, particularly in pts with non-malignant diseases. A T cell depleted haploidentical HSCT (T-haplo-SCT) expands donor availability while exhibiting low GvHD rates. In our single center pilot study, we compared T-haplo-SCT with a MSD HSCT in pts with advanced stage SCD, using almost identical transplant conditions except donor source and GvHD prophylaxis.Methods17 pts were transplanted for advanced stage SCD-related complications. Five SCD pts received bone marrow (BM) from a MSD and 12 peripheral blood stem cells (PBSC) from a haploidentical donor. The conditioning regimen for both groups consisted of thiotepa (2x5mg/kg), fludarabine (4x40mg/m2), treosulfan (3x14g/m2) and anti-thymocyte globulin (ATG, Neovii, 3x15mg/kg), given on day -9 to -7 for T-haplo-SCT and on days -3 to -1 for MSD. In addition, Cyclosporine A (CSA) or Tacrolimus and MMF was applied for GvHD prophylaxis. All pts underwent exchange transfusions prior to conditioning and means of fertility preservation. The MSD pts included four females and one male, median age 22 years (range 9 to 25 years). Three suffered from homozygous SCD, two from HbS/ß-thalassemia. The BM graft consisted of a median of 2,2 x 106 CD34+ cells/kg bodyweight, with a A/S in three and a A/A genotype in two donors. In T-haplo-SCT, five were females and seven were males. Median age was 18 yrs (range 3 to 28 yrs). Nine had homozygous SCD, three HbS/ß-thalassemia. The PB grafts consisted of a median of 12,2 x 106 CD34+ cells, 11,2 x 103 CD3+ and 23,3 x 103 CD19+ cells/kg. Haploidentical donors were fully haplotype mismatched relatives (1 mother, 8 fathers, 1 cousin, 1 sister and one step sister). Donor genotype was Hb A/A in one and Hb A/S in all others.ResultsThe median follow-up was 21 months in the MSD group and 26 months in T-haplo-SCT group. The median hospitalization was 38 days for both. The median time to engraftment was faster in T-haplo-SCT versus MSD: 16 versus 23 days for leukocytes, 18 versus 23 days for granulocytes and 11 versus 21 days for thrombocytes. The median T (>500/µl) and B cell recovery (>100/µl) in T-haplo-SCT versus MSD was 115 versus 103 days and 85 versus 140 days, respectively.Two pts in the T-haplo-SCT group developed a stable mixed PB chimerism with no SCD-related complications off immunosuppression. Lineage specific chimerism analyses of red cell precursors (CD235a, glycophorine A) in the BM of these pts showed a complete red cell chimerism. The median HbS level off immunosuppression was comparable in both groups (37-38%). In all 17 pts, the conditioning regimen was well tolerated. Mild veno-occlusive disease (VOD/SOS) was diagnosed in 1 MSD patient and a transient thromboembolic event in one T-haplo-SCT patient. One patient developed a life threatening capillary leak syndrome during ATG treatment and subsequent PRES and was rescued by a switch to everolimus MMF prophylaxis. One patient from the T-haplo-SCT succumbed to a CMV pneumonitis combined with rotavirus gastroenteritis. None of our pts developed a grade III-IV acute GvHD. Five T-haplo-SCT and one MSD patient developed steroid responsive grade I-II acute GvHD. One of five MSD and three of twelve T-haplo-SCT pts developed mild to moderate steroid responsive chronic GvHD, which resolved in the meantime. CMV and EBV reactivations were observed but could be treated with standard of care except one patient mentioned above. One patient after T-haplo-SCT developed BK virus nephritis. All pts are stably engrafted off immunosuppression and free of SCD-related complications.ConclusionsIn our experience T-haplo-SCT with CD3+/CD19+ depleted PBSC is safe and efficient with a very low incidence of GvHD and is at least comparable to MSD HSCT, even for advanced stage SCD pts. DisclosuresCorbacioglu:Jazz Pharmaceuticals: Consultancy, Honoraria.

Comparable Outcomes After Alternative and Matched Sibling Donor Hematopoietic Stem Cell Transplantation and the Role of Molecular Measurable Residual Disease for Acute Myeloid Leukemia in Elderly Patients

Allogeneic hematopoietic stem cell transplantation (HSCT) remains the most effective postremission therapy conferring the chance of cure for acute myeloid leukemia (AML), including elderly patients. Although the number of transplantations for elderly patients with AML (eAML) is increasing owing to greater availability of various graft sources together with the adoption of advanced supportive care and reduced-intensity conditioning (RIC) regimen, there are relatively limited data on the impact of donor type in eAML compared to younger patients. In addition, few studies have evaluated the role of pretransplantation measurable residual disease (MRD) in the elderly population. Given the lack of prospective comparative study, we retrospectively compared transplantation outcomes of elderly patient with AML receiving allo-HSCT from matched sibling donor (MSD-HSCT), matched unrelated donor (MUD-HSCT) or haploidentical related donor (Haplo-HSCT), or autologous HSCT (Auto-HSCT). A total of 154 patients with a median age of 63 years (range 60-74) underwent MSD-HSCT (n = 41), MUD-HSCT (n = 36), Haplo-HSCT (n = 55), or Auto-HSCT (n = 22) for AML. RIC regimens were used in the majority of patients. In Haplo-HSCT, T-cell-replete peripheral blood stem cells with unique RIC regimens using anti-thymocyte globulin (ATG)-based GVHD prophylaxis was used. In the analysis, adjustment for MRD status at the time of transplantation was performed. MRD was measured by the quantitative molecular assays of the targets, including RUNX1-RUNX1T1, CBFB-MYH11, and NPM1, or WT1 in the absence of abnormalities in the aforementioned targets. At a median follow-up of 48 months, survival rates were similar between different donor types, whereas nonrelapse mortality (NRM) was lower in MUD-HSCT compared to MSD-HSCT (P = .002). MSD-HSCT, in which the majority of patients received a conditioning regimen not including ATG, showed more frequent severe chronic graft-versus-host disease (cGVHD). The major causes of non-relapse deaths in MSD-HSCT were related to cGVHD (71%), whereas infectious complications were mainly related to NRM in Haplo-HSCT (50%) or Auto-HSCT (100%). In the MUD-HSCT, GVHD (57%) and infection (43%) contributed similarly to non-relapse death. Cytomegalovirus infection was more frequent in Haplo-HSCT. In multivariate models, pre-transplant MRD-positivity was an independent risk factor for relapse (P = .001), whereas older age (P = .002) and the hematopoietic cell transplantation-comorbidity index (P = .009) were useful in predicting NRM. The current study demonstrated comparable outcomes after alternative and matched sibling donor HSCT in eAML aged 60 years or older, and the results also suggest the necessity for more sophisticated strategies to reduce NRM or relapse according to each donor type. The usefulness of molecular MRD assays demonstrated herein will facilitate trials for MRD-driven decision-making or risk-adaptive approaches in eAML.

G-CSF-Primed Peripheral Blood Stem Cell Haploidentical Transplantation Could Achieve Satisfactory Clinical Outcomes for Acute Leukemia Patients in the First Complete Remission: A Registered Study.

G-CSF-mobilized peripheral blood (G-PB) harvest is the predominant graft for identical sibling donor and unrelated donor allogeneic hematopoietic stem cell transplantation (HSCT) recipients, but it was controversial in haploidentical related donor (HID) HSCT. In this registry study, we aimed to identify the efficacy of HID G-PB HSCT (HID-PBSCT) for acute leukemia (AL) patients in first complete remission (CR1). Also, we reported the outcomes for the use of G-PB grafts in comparison with the combination of G-BM and G-PB grafts in HID HSCT recipients. Sixty-seven AL patients in CR1 who received HID-PBSCT were recruited at Institute of Hematology, Peking University. Patients who received haploidentical HSCT using the combination of G-BM and G-PB harvests in the same period were enrolled as controls (n=392). The median time from HSCT to neutrophil and platelet engraftment was 12 days (range, 9–19 days) and 12 days (range, 8–171 days), respectively. The 28-day cumulative incidence of neutrophil and platelet engraftment after HSCT was 98.5% and 95.5%, respectively. The cumulative incidences of grade II–IV and grade III–IV acute graft-versus-host disease (GVHD) were 29.9% (95%CI 18.8–40.9%) and 7.5% (95%CI 1.1–13.8%), respectively. The cumulative incidences of total and moderate-severe chronic GVHD were 54.9% (95%CI 40.9–68.8%) and 17.4% (95%CI 6.7–28.0%), respectively. The cumulative incidences of relapse and non-relapse mortality were 13.9% (95%CI 5.4–22.5%) and 3.4% (95%CI 0–8.1%), respectively. The probabilities of overall survival (OS) and leukemia-free survival (LFS) were 84.7% (95%CI 74.7–94.7%) and 82.7% (95%CI 73.3–92.1%) respectively. Compared with the HID HSCT recipients using the combination of G-BM and G-PB grafts, the engraftments of neutrophil and platelet were both significantly faster for the G-PB group, and the other clinical outcomes were all comparable between the groups. In multivariate analysis, graft types did not influence the clinical outcomes. Overall, for the patients with AL CR1, G-PB graft could be considered an acceptable graft for HID HSCT recipients. This study was registered at https://clinicaltrials.gov as NCT03756675.

32 - Non T–Cell Depleted Haploidentical Versus Matched Sibling Donor Hematopoietic Stem Cell Transplantation in Adult Patients with Acute Lymphoblastic Leukemia in Remission: A Study from the Acute Leukemia Working Party of the European Society for Blood and Marrow Transplantation

32 - Non T–Cell Depleted Haploidentical Versus Matched Sibling Donor Hematopoietic Stem Cell Transplantation in Adult Patients with Acute Lymphoblastic Leukemia in Remission: A Study from the Acute Leukemia Working Party of the European Society for Blood and Marrow Transplantation

Feasibility of reduced-dose posttransplant cyclophosphamide and cotransplantation of peripheral blood stem cells and umbilical cord-derived mesenchymal stem cells for SAA

Posttransplant cyclophosphamide (PTCy) as graft-versus-host disease (GVHD) prophylaxis is an effective strategie for patients receiving matched sibling donor hematopoietic stem cell transplantation (MSD-HSCT) and haploidentical HSCT (haplo-HSCT). We evaluated the effectiveness and safety of reduced-dose cyclophosphamide, 20 mg/kg for 13 patients in MSD-HSCT cohort and 25 mg/kg for 22 patients in haplo-HSCT cohort, on days + 3, + 4 combined with cotransplantation of peripheral blood stem cells (PBSCs) and human umbilical cord-derived mesenchymal stem cells (UC-MSCs) for severe aplastic anemia (SAA). In MSD-PTCy cohort, the times to neutrophil and platelet engraftment were significantly shorter than those in the MSD-control cohort (P < 0.05). The cumulative incidence of acute GVHD (aGVHD) at day + 100 (15.4%) was lower than that in the MSD-control cohort (P = 0.050). No patient developed chronic GVHD (cGVHD). The 1-year overall survival (OS) and event-free survival (EFS) rates were 100% and 92.3%. In haplo-PTCy cohort, the times to neutrophil and platelet engraftment were significantly shorter than those in the haplo-control cohort (P < 0.05). The cumulative incidences of aGVHD at day + 100 and 1-year cGVHD were 31.8% and 18.2%, and the 1-year OS and EFS rates were 81.8% and 66.9%. Reduced-dose PTCy and cotransplantation of PBSCs and UC-MSCs is an acceptable alternative to patients with SAA.

Impact of Low-Dose rATG Prior to Matched Sibling Donor Hematopoietic Stem Cell Transplantation for Hematologic Malignancies: Reduced Risk of Chronic Graft-versus-Host Disease and Improved Survival Outcomes.

PurposeTo explore the efficacy of low-dose rabbit antithymocyte globulin (rATG) in matched sibling donor hematopoietic stem cell transplantation (MSD-HSCT) for patients with acute leukemia or myelodysplastic syndrome.Patients and MethodsWe performed a retrospective study of 79 patients with hematologic malignancies who received MSD-HSCT. All patients received standard graft-versus-host disease (GVHD) prophylaxis comprising cyclosporine, mycophenolate mofetil and short-term methotrexate. Among them, 38 were administered 5 mg/kg rATG as part of GVHD prophylaxis. Clinical outcomes including overall survival (OS), GVHD and relapse were analyzed.ResultsNo graft failure occurred in the antithymocyte globulin (ATG) or non-ATG group. The cumulative incidences of grade 2–4 and 3–4 acute GVHD at day +100 were 13.3% versus 19.5% (p=0.507) and 5.7% versus 15.2% (p=0.196), respectively. The 2-year cumulative incidences of chronic GVHD (cGVHD) were 35.4% and 60.4% (p=0.039), and those of extensive cGVHD were 12.9% and 40.0% (p=0.015), respectively. In a multivariate analysis, the use of low-dose rATG was an independent protective factor for extensive cGVHD (hazard ratio [HR] 0.256; 95% confidence interval [CI], 0.080 to 0.822, p=0.022). The 2-year OS was 88.1% and 68.4% (p=0.038), respectively, and the use of low-dose rATG was the only protective factor in the multivariate analysis (HR 0.216; 95% CI, 0.059 to 0.792, p=0.021). There was no significant difference between the two groups in terms of the 2-year cumulative incidence of relapse, leukemia-free survival or GVHD-free and relapse-free survival.ConclusionLow-dose rATG used in MSD-HSCT as part of the conditioning regimen results in a reduced incidence of cGVHD and improves survival outcomes.

Efficacy of Haploidentical Hematopoietic Stem Cell Transplantation in Treatment of Intermediate Risk Acute Myeloid Leukemia with Negative for FLT3-ITD, NPM1 or Biallelic CEBPA Mutation

To compare the efficacy of haploidentical hematopoietic stem cell transplantation (hi-HSCT) HLA-matched sibling donor hematopoietic stem cell transplantation (MSD-HSCT) and post-remission chemotherapy (PR-CT) in treatment of intermediate risk acute myeloid leukemia with negative for FLT3-ITD, NPM1 or biallelic CEBPA mutation. The clinical data of patients with intermediate risk NPM1wt/non-CEBPAdm/FLT3-ITDneg AML from October 2009 to May 2016 were retrospectively analyzed. The overall survival rate of the patients treated with PR-CT, MSD-HSCT or hi-HSCT was 63.7%, 71.7%, 75.5%, respectively (P＜0.05); the disease-free survival (DFS) rate was 52.8%, 67.1%, 71.3% respectively (P＜0.001); the cumulative incidence of relapse was 24.7%, 16.9%, 14.4% respectively (P＜0.05); the non-relapse mortality was 26.2%, 17.3%, 14.4% reapectively (P＞0.05). The analysis of transplantation, related adverse events showed that II-IV grade of aGVHD in the MSD-HSCT group and hi-HSCT group was 48.9% and 45.6% respectively (P＞0.05); the extensive cGVHD event was 21.6% and 8.8% (P＜0.05) respectively. The efficiency of hi-HSCT and MSD-HSCT is superior to that of PR-CT for treatment of patients with intermediate risk NPM1wt/non-CEBPAdm/FLT3-ITDneg AML after CR1, there is no statistically significant difference in the efficiency of consolidatorg treatment and the transplantation-related mortality between hi-HSCT and MSD-HSCT.