Haplo Hematopoietic Stem Cell Transplantation Research Articles

Flow Cytometry-Based Pre-Transplant Minimal Residual Disease Detection Strongly Impacts on the Outcome of Haploidentical Transplantation with Αβ T Cell Depletion in Pediatric Acute Lymphoblastic Leukemia

Introduction Allogeneic hematopoietic stem cell transplantation (HSCT) is indicated for patients with relapsed or refractory acute lymphoblastic leukemia. Patients with persistence of minimal residual disease (MRD) before HCT are at increased risk of disease relapse. Multiparameter flow cytometry (MFC) is the most commonly used method of MRD detection in clinical practice. This study aimed to evaluate MRD status before HCT on outcome of ALL patients receiving allogeneic HSCT from haploidentical donors with TCRαβ+/CD19+ depletion of the graft. Materials and methods A total of 120 pts with ALL (T-lineage ALL (T-ALL)- 37, B cell precursor (BCP)-ALL-83, 45 female, 75 male, median age 8.7 years (0.5-20) underwent allogeneic HSCT between June 2013 and June 2019. All pts received Haplo graft and were in morphologic remission. Disease status at transplant was CR1 in 35 pts, CR2 in 68 pts and CR>2 in 17 pts. Transplantation in CR1 was performed according to risk stratification scheme in the current institutional ALL protocol (Moscow-Berlin 2008, 2015). MRD detection in the bone marrow prior to НSСТ was performed in all pts by MFC according the AIEOP BFM FLOW Network SOP. MRD negativity was defined as <0.001% of all bone marrow nucleated cells. Seventy-nine patients were MRD negative before HSCT, 41 were MRD-positive. The median MRD level (among MRD-positive patients) prior HCT was 0.025%. Thirty (25%) pts received treosulfan-based myeloablative preparative regimen, while TBI-based regimen was used in 90 (75%) pts. Two regimens of GvHD prophylaxis were used. Regimen 1 (n=27): thymoglobulin 5mg/kg, rituximab 200 mg/m2 and bortezomib on day +2, +5; regimen 2 (n=93): tocilizumab at 8 mg/kg on day -1 and post-transplant bortezomib, 89 pts receive additional abatacept at 10 mg/kg on day +2, +7, +14, +28. TCR αβ+/CD19+ depletion of HSCT with CliniMACS technology was implemented in all cases. The median dose of CD34+ cells was 9.3 x106/kg (range 4.3-19.8), αβ T cells - 30x103/kg (range 1-361). Median time of follow-up for survivors was 1.6 years (range: 0.13 - 4.8). Results Primary engraftment was achieved in 116 of 120 pts (3 pts died before engraftment due to septic events, one relapsed early), the median time to neutrophil and platelet recovery was 13 and 14 days, respectively. All engrafted pts had verified morphologic remission and achieved sustained complete donor chimerism by day +30, seven of them had detectable MRD (5 of them were MRD-positive before HCT). Transplant-related mortality was 5 % (95% CI: 2-11). The cumulative incidence (CI) of relapse at 1.5 years was 25%(95%CI:18-35) for the whole cohort. Among patients, who had MRD-negative remission prior to HSCT, CI of relapse was 14 % (95%CI:8-26) with median time of relapse of 0.54 months, as compared to MRD-positive cohort, with CI of relapse of 44 % (95%CI:31-63) with median time to relapse 0.29 months, p=0.0004. pEFS (event=death or relapse) was 70% (95%CI: 61-78) for the whole cohort, in MRD (-) group pEFS was 79% (95%CI: 68-88), as compared to 56%(95%CI:40-72) in the MRD(+) group, p=0.025. CI of relapse in BCP-ALL pts, who had MRD-negative remission prior to HCT was 12 %(95%CI:6-25), in MRD(+) group 49% (95%CI:33-72), p=0.0002, in T-ALL pts in MRD (-) and MRD (+) groups CI of relapse was 17 % (95%CI:6-51) and 38 % (95%CI:20-76), respectively, p=0.14. Conclusion These results suggest that MRD detection by multiparameter flow cytometry prior to HSCT is a highly significant prognostic factor in the setting of haploidentical HSCT on the platform of ab T cell depletion. We expect that further improvement of the outcome can be achieved based on the combination of current safe haplo HSCT platform and novel targeted immunotherapy approaches. Figure Disclosures Maschan: Miltenyi Biotec: Other: lecture fee.

Unmanipulated haploidentical transplantation for adult patients with hematological malignancies.

Unmanipulated haploidentical transplantation for adult patients with hematological malignancies.

Clinical analysis of bronchiolitis obliterans syndrome after haplo- hematopoietic stem cell transplantation

目的探讨单倍型造血干细胞移植（haplo-HSCT）后闭塞性细支气管炎综合征（BOS）的临床特征、危险因素以及预后。方法回顾性分析苏州大学附属第一医院2013年1月至2015年12月444例行haplo-HSCT且总生存（OS）期>100 d患者的临床资料。结果至2018年1月1日随访结束，共计25例（5.63%）患者发生BOS（BOS组），中位发病时间为移植后448（165~845）d，移植后1、2、3年BOS累积发生率分别为1.6%（95%CI 1.5%~1.6%）、4.8%（95%CI 4.7%~4.8%）、5.8%（95%CI 5.7%~5.8%）；在慢性移植物抗宿主病（cGVHD）患者中，移植后1、2、3年BOS累积发生率分别为2.8%（95%CI 2.7%~2.8%）、9.5%（95%CI 9.4%~9.5%）、11.5%（95%CI 11.4%~11.6%）。多因素分析结果显示疾病高危、Ⅱ~Ⅳ度急性移植物抗宿主病（aGVHD）、BOS发生前存在其他部位cGVHD是BOS发生的独立危险因素。BOS组、非BOS组移植后3年OS率分别为71.8%（95%CI 53.9%~89.6%）、72.4%（95%CI 68.1%~76.7%）（P=0.400）；然而，半标志性分析结果显示，BOS组从BOS诊断至随访截止1、3年OS率分别为78.4%（95%CI 61.5%~95.3%）、37.0%（95%CI 2.5%~71.5%），非BOS组从移植后448 d（标志点）至随访截止1、3年OS率分别为93.9%（95%CI 91.3%~96.4%）、89.3%（95%CI 84.8%~93.0%）（P<0.001）。BOS组3年移植相关死亡率（TRM）显著高于非BOS组（28.2%对10.9%，P<0.001）。重度BOS患者OS率显著低于轻、中度BOS患者（P=0.049）。结论BOS是haplo-HSCT后重要并发症，疾病高危、Ⅱ~Ⅳ度aGVHD、BOS发生前存在其他部位cGVHD是BOS发生的独立危险因素。BOS患者预后较差。

Administration of BPX-501 Cells Following Αβ- T and B-Cell-Depleted HLA-Haploidentical HSCT in Children with Fanconi Anemia

Abstract Background Allogeneic hematopoietic stem cell transplantation (HSCT) has been shown to rescue trilineage cytopenias and to prevent occurrence of myeloid malignancies in patients with Fanconi Anemia (FA). HLA-identical family donor HSCT is a recommended treatment strategy with an ≥80% cure rate, and outcomes of HSCT from unrelated donors have progressively improved over time. However, HLA-partially matched (haplo) HSCTs have been historically associated with inferior results. Innovative approaches of graft manipulation, such as selective depletion of αβ-T and B cells, have recently been reported to improve the outcomes of haplo-HSCT in children with non-malignant disorders, however obstacles remain, such as delayed recovery of adaptive immunity with a risk of life-threatening infections. Novel strategies aimed at accelerating immune reconstitution are warranted to optimize the outcomes of patients transplanted from a HLA-haploidentical family donor. BPX-501 is an allogeneic product consisting of T cells modified to express the inducible caspase-9 (iC9) safety switch and truncated CD19 to allow monitoring and expansion of BPX-501 following transplant. The polyclonal nature of the BPX-501 provides broad virus and tumor-specific immunity, while the safety switch provides the unique ability to promptly and durably resolve graft-versus-host disease (GvHD) symptoms following the administration of rimiducid which induces dimerization and activation of iC9, inducing apoptosis of BPX-501. Aims To evaluate the safety and efficacy (acceleration of immune recovery and prevention of transplant-related mortality while maintaining low rates of acute and chronic GvHD) of BPX-501 administered after a αβ T and B-cell depleted haplo-HSCT in pediatric patients with FA. Methods This is a multicenter US (NCT03301168) and EU (NCT02065869), prospective trial utilizing αβ-T- and B-cell-depleted haplo-HSCT followed by infusion of donor lymphocytes genetically modified to express iC9 (BPX-501 T cells). BPX-501 cells were planned to be infused on day14±4 after the allograft per protocol. No post-transplant pharmacological GvHD prophylaxis was employed. Patients who develop GvHD resistant to conventional steroid therapy were eligible to receive ≥1 dose of dimerizing rimiducid activating iC9. The efficacy-evaluable population (EEP) was defined as any patient with FA who received HSCT, BPX-501 infusion and had at least one follow-up assessment. Results At the time of clinical cut-off (June 30th, 2018), 14 patients met the EEP definition. Nine and 5 patients were transplanted in the EU and US, respectively. The median follow-up was 23.5 mos (0.75 - 42 mos). Key baseline and transplant characteristics are detailed in Table 1. The median time for neutrophil and platelet engraftment was 14 (11-15) and 10 (8 - 11) days, respectively. One patient experienced primary graft failure (7.7% [95% CI: 0-22.2%]). Only one patient developed Grade I aGvHD (7.7% [95% CI: 0-22.2%]). Two patients developed cGvHD (19.2% [95% CI: 4-43.2%]), both cases being moderate. Rimiducid was not administered to any patient. One patient died after transplantation due to brain hemorrhage 25 days post HSCT. The event was unrelated to BPX-501 (TRM 7.1% [95% CI: 0-20.6%]). No patients died of infectious complications. The probability of both overall survival (OS) and disease-free survival (DFS) was 92.9% (95% CI: 79.4-100%). The median time from last red blood cell (RBC) transfusion was 23.6 mos (0.2 - 41.9 mos). CD3+ and CD3+CD4+ T cells above 500 cells/ml were achieved by 180 and 360 days, respectively. IgA and IgM levels achieved normal values by 30 and 180 days, respectively. The percentage of circulating and median absolute BPX-501 cells at Day 100 were 3.35% ± 2.94% (0 - 8.4%) and 29.09 ± 39.56 cells/ml (0 - 135 cells/ml), respectively. Conclusion These data indicate that the adoptive transfer of BPX-501 following αβ-T and B-cell depleted haplo-HSCT represents a novel and highly effective transplantation strategy for pediatric patients with FA. Further, despite the addition of BPX-501, low rates and severity of both acute and chronic GvHD was observed, a finding that could translate into significant long-term benefit, in terms of reduction of squamous cell carcinoma a well-known complication occurring in FA patients after HSCT. Disclosures Aldinger: Bellicum Pharmaceuticals, Inc.: Employment. Locatelli:Bellicum: Consultancy, Membership on an entity's Board of Directors or advisory committees; Miltenyi: Honoraria; Novartis: Consultancy, Membership on an entity's Board of Directors or advisory committees; bluebird bio: Consultancy; Amgen: Honoraria, Membership on an entity's Board of Directors or advisory committees.

Thrombospondin-1, Platelet Factor 4, and Galectin-1 Are Associated with Engraftment in Patients with Sickle Cell Disease Who Underwent Haploidentical HSCT

BackgroundSickle cell disease (SCD) is an inherited red blood cell disorder which leads to significant morbidity and early mortality. The most widely available curative approach remains hematopoietic stem cell transplantation (HSCT). However, <15% SCD patients have human leukocyte antigen (HLA)- matched sibling donors. HLA-haploidentical (haplo) HSCT expands the donor pool considerably and is a practical alternative for these patients, but with an increased risk of allograft rejection. Biomarkers in patient plasma could potentially be helpful in predicting HSCT outcome and allow treatment at an early stage so that graft rejection could be reversed or prevented.ObjectiveThe purpose of the study was to detect variations in the plasma proteomes of engrafted patients as compared to those who rejected their grafts and elucidate mechanisms associated with engraftment.MethodsPatients were conditioned with alemtuzumab, 400cGy total body irradiation, and a dose escalation of post-transplant cyclophosphamide ranging from 0-100mg/kg (Fitzhugh CD et al. Blood Advances, 2017). Tandem Mass Tag (isobaric tags for relative quantification) was performed on plasma samples from engrafted (N=9) and rejected patients (N=10) who underwent haplo HSCT. Proteins with p-values <0.05, relative difference in protein concentration between groups >25%, and total number identified peptide sequences >2 were considered statistically significant. Bioinformatics tools (DAVID, GeneMANIA, STRING and LENS) were used to analyze the identified proteins. Biologically relevant proteins were further evaluated by ELISA to verify their association with the allograft status.ResultsThe proteomics analysis revealed 44 differentially expressed proteins between engrafted and rejected groups. Seven candidate proteins, namely thrombospondin-1 (TSP-1), platelet factor 4 (PF4), talin-1, moesin, cell division control protein 42 homolog, galectin-1 (GAL-1), and CD9 were selected for further analysis. Pathway enrichment analysis revealed that the differentially expressed proteins were mostly related to focal adhesion, rap1 signaling pathway, regulation of actin cytoskeleton platelet activation, and leukocyte transendothelial migration. The interaction network of the identified proteins indicated that the proteins were partially biologically connected.ELISA results of the 7 proteins revealed that TSP-1, PF4, and GAL-1 were significantly higher in the engrafted group as compared with the rejected group, African-American healthy volunteer group, and SCD group who had not been transplanted (see Figure 1). TSP-1 has been found to promote the survival of corneal transplants and is a major activator of transforming growth factor (TGF)-b signaling pathway (Saban DR et al. J Immunol, 2010), an important player in the initiation of immunological tolerance. PF4 has been observed to be associated with improved outcome in cardiac and kidney transplants (Shi G et al. J Clin Invest, 2014 and Zhang L et al. Inflammation, 2015), to enhance proliferation of regulatory T-cells, and to decrease Th17 differentiation (Shi G et al. J Clin Invest, 2014). Lastly, GAL-1 has been found to induce regulatory T- and regulatory B-cell function (Alhabbab R et al. Sci Rep, 2018).ConclusionsWe have shown for the first time that TSP-1, PF4,and GAL-1 are associated with engraftment in patients with SCD who undergo haplo HSCT. The study warrants further validation in a larger sample size as well as in vitro and in vivo analyses to evaluate whether our candidate proteins are associated with tolerance induction. [Display omitted] DisclosuresNo relevant conflicts of interest to declare.

Low Dose Anti-Thymocyte Globulin Plus Low Dose Post-Transplant Cyclophosphamide As Graft-Versus-Host Disease Prophylaxis in Haploidentical Peripheral Blood Stem Cell Transplantation for Patients with Hematologic Malignancies: A Prospective, Phase II Study

Background:Nowadays, the most wildly used regimens for graft-versus-host disease (GvHD) prophylaxis in haplo-hematopoietic stem cell transplantation (Haplo-HSCT) were based on in vivo T cell depletion (TCD) with anti-thymocyte globulin (ATG) or post-transplant cyclophosphamide (PTCy). To improve the efficiency of GvHD prophylaxis in haploidentical peripheral blood stem cell transplantation (Haplo-PBSCT), a novel regimen, which is composed of low dose of ATG (5 mg/kg) and low dose PTCy (50mg/kg) for GvHD prophylaxis, was evaluated in a prospective phase II clinical trial (Clinicaltrials.org NCT03395860).Method:Thirty-two patients with hematological malignancies were enrolled in this trial. Median age was 37 years (range, 20 to 62 years). At the time of transplantation, a total of fourteen patients with AML/ALL reached first or subsequent complete response (CR1, ≥CR2); the other eighteen patients had active disease including three ALL, three MDS-EB II, two CMML and ten AML patients. All patients received myeloablative conditioning regimens except for three patients. The GvHD prophylaxis contained ATG 2.5mg/kg administered on day -2 to -1 and cyclophosphamide (Cy) 50 mg/kg on day +3, cyclosporine A (CsA) and mycophenolate mofetil (MMF) initiating on day +4. The PBSC grafts for all patients were mobilized with G-CSF. Unrelated cord blood (UBC) was infused as the third party cells at 4 hours before PBSC graft infusionResults: All patients received PBSC grafts with MNCs 15.5 (7.5-28.3) ×108/kg and CD34+ cells 13.39 (2.4-31.7) ×106/kg. The median nuclear cell number and CD34+ cell number of unrelated third party cord blood were 2.1 (1.4-4.14) ×107/kg and 5.6 (1.52-11.2) ×104/kg, respectively. The median time for neutrophil and platelet engraftment was 12 days (range 9-20) and 16 days (range 12-25), respectively. Chimerism monitoring showed that all the patients were fully donor chimerism between days 14 to 28 after transplantation. There was no chimerism of cord blood cells in all patients on days 14 after transplantation. Primary graft failure occurred in one patient (3.1%).One patient with AML experienced secondary graft failure after CMV pneumonia at day 90. The cumulative incidences (CIs) of grades II-IV and III-IV acute GvHD were 19.4% (95% CI, 5.5-33.3%) (Figure A) and 6.9% (95% CI 0-16.3%) (Figure B) by day 100, respectively. The CIs within six months of moderate-to-severe cGVHD were 18.8% (5/27 cases) (95% CI, 3.9%-33.7%)(Figure C). No patient died from acute and chronic GvHD. The one-year probability of relapse was 25.1% (95% CI, 7.3-42.9%)(Figure D). The one-year probabilities of disease free-survival (DFS) and overall survival (OS) were 59% (95% CI, 33.3%-84.7%) and 78.4% (95% CI, 63%-93.8%)(Figure E), respectively. The CIs of CMV reactivation and EBV reactivation by day 180 were 37.5% (95% CI, 19.8-55.2%) and 40.6% (95% CI, 22.6-58.6%), respectively. Non-relapse mortality (NRM) was 9.4 %.Conclusion: The results suggested that low dose ATG with low dose PTCy as GvHD prophylaxis in Haplo-PBSCT had promising activity. [Display omitted] DisclosuresNo relevant conflicts of interest to declare.

Low-dose anti-thymocyte globulin plus low-dose posttransplant cyclophosphamide as graft-versus-host disease prophylaxis in haploidentical peripheral blood stem cell transplantation combined with unrelated cord blood for patients with hematologic malignancies: a prospective, phase II study

Nowadays, the most wildly used regimens for graft-versus-host disease (GvHD) prophylaxis in haplo-hematopoietic stem cell transplantation (Haplo-HSCT) are based on in vivo T-cell depletion (TCD) with anti-thymocyte globulin (ATG) or posttransplant cyclophosphamide (PTCy). To improve the efficiency of GvHD prophylaxis in haploidentical peripheral blood stem cell transplantation combined with unrelated cord blood (Haplo-PBSCT-Cord), a novel regimen, which is composed of low dose of ATG (5 mg/kg) and low-dose PTCy (50 mg/kg) for GvHD prophylaxis, was evaluated in a prospective phase II clinical trial (Clinicaltrials.org NCT03395860). Thirty-two patients diagnosed with hematological malignancies were enrolled in this trial. All patients received myeloablative conditioning regimens except for three patients. The cumulative incidences (CIs) of grades II-IV and III-IV acute GvHD were 19.4% (95% CI, 5.5−33.3%) and 6.9% (95% CI, 0−16.3%) by day 100, respectively. The 1-year probability of relapse, disease free survival (DFS) and overall survival (OS) was 25.1% (95% CI, 7.3−42.9%), 59% (95% CI, 33.3−84.7%) and 78.4% (95% CI, 63−93.8%), respectively. The CIs of CMV and EBV reactivation by day 180 were 37.5% (95% CI, 19.8−55.2%) and 40.6% (95% CI, 22.6−58.6%), respectively. The results suggested that low-dose ATG with low-dose PTCy as GvHD prophylaxis in Haplo-PBSCT-Cord had promising activity.

Clinical analysis of hemorrhagic cystitis in children and adolescents with hematological diseases post haplo-hematopoietic stem cell transplantation

目的观察儿童及青少年血液病患者单倍型造血干细胞移植（haplo-HSCT）后出血性膀胱炎（HC）的临床特征并探讨其影响因素。方法回顾性分析2015至2016年接受haplo-HSCT的89例儿童及青少年血液病患者的临床资料。结果全部89例患者中，≤14岁62例（儿童组）、>14~<18岁27例（青少年组）；男56例，女33例；中位移植年龄10（1~17）岁；急性淋巴细胞白血病（ALL）44例，急性髓系白血病（AML）33例，急性混合细胞白血病（AHL）3例，骨髓增生异常综合征（MDS）9例。移植物来源均为骨髓+外周血干细胞。全部89例患者中32例（36%）发生HC，其中迟发型31例，早发型1例；Ⅰ度6例、Ⅱ度16例、Ⅲ度8例、Ⅳ度2例；HC发病中位时间为移植后25（2~55）d，中位持续时间为19（3~95）d；所有患儿均获得治愈。儿童组HC发病率低于青少年组[27.4%（17/62）对55.6%（15/27），χ2=6.466，P<0.05]。儿童组中<5岁组HC发生率低于5~14岁组[0（0/12）对34%（17/50），χ2=4.043，P<0.05]。结论HC是儿童及青少年血液病患者haplo-HSCT的常见并发症，总体预后良好，年龄是其发生的影响因素。

Preemptive Therapy of HHV-6 Encephalitis with Foscarnet Sodium for High Risk Patients After Hematopoietic Stem Cell Transplantation.

Abstract 4655Umbilical cord blood from unrelated donors has been successfully used as an alternative hematopoietic stem cell source to treat hematologic malignancies in patients lacking HLA-matched donors. However, umbilical cord blood transplantation (UCBT) is associated with a higher risk of engraftment failure and more delayed immunological recovery than bone marrow transplantation and peripheral blood stem cell transplantation (PBSCT). Recently, human herpesvirus-6 (HHV-6) has been recognized as an important pathogen in allogeneic hematopoietic stem cell transplantation (HSCT). In particular, HHV-6 reactivation often causes limbic encephalitis with a dismal prognosis. We conducted a prospective, multicenter study to assess the safety and efficacy of preemptive therapy with foscarnet sodium (PFA) to prevent HHV-6 encephalitis after HSCT. Materials and methodsEligible patients were aged from 16 to 75 years with hematologic disorders refractory to conventional therapy and considered to require UCBT or HLA 1-haplotype mismatched HSCT (haplo HSCT) due to the unavailability of an HLA-identical relatives or a suitable unrelated donor. Informed consent was obtained from all subjects according to the Declaration of Helsinki, and this study protocol was approved by the institutional ethical committee. The amount of plasma HHV-6 DNA was measured 3 times per week between day 7 and day 36 after UCBT or PBSCT from HLA-haploidentical relative donors. PFA, 90 mg/kg/day, was given when the amount of HHV-6 DNA exceeded 5 ×102 copies/ml. ResultsOf 20 cases registered between September 2007 and January 2009, 12 of 15 UCBT recipients (80%) became positive for HHV-6 DNAemia, and 7 cases exceeded 5×102 copies/ml, while none of the 5 patients who received haplo HSCT became positive (UCBT vs. haplo HSCT; p<0.004). HHV-6 reactivation occurred earlier in patients who eventually required PFA due to an increase in the HHV-6 DNA copy number greater than 5×102 copies/ml than in patients who did not require PFA treatment (median date of developing HHV-6 DNAemia, day 17 vs. day 22 after HSCT, p<0.02). PFA was given to 7 patients whose HHV-6 DNA copy number exceeded 5×102 copies/ml on day 15 to day 20 (median, day 17) after UCBT. The amount of HHV-6 DNA in the plasma decreased the day after PFA administration in 4 of 7 patients, while the other 3 patients required 3-4 days until the copy number decreased. Two patients showed an increase in HHV-6 DNA copy number greater than 1×104 /ml prior to the initiation of PFA without accompanying symptoms suggestive of encephalitis. One patient developed limbic encephalitis with mild symptoms just after initial PFA administration, but the encephalitis resolved without any neurologic sequelae. Mild and transient adverse effects were associated with PFA in only 2 of 8 patients. ConclusionPFA administration guided by the HHV-6 copy number in the early posttransplant period is safe and may reduce the risk of severe limbic encephalitis. Disclosures:Nakao:Alexion: Research Funding.