Incidence Of Acute Graft-versus-host Disease Research Articles

Comparison of Myeloablative Versus Reduced-Intensity Fludarabine/Busulfan Regimen in Patients with Myelodysplastic Syndrome Undergoing Allogeneic Hematopoietic Stem Cell Transplantation

Comparison of Myeloablative Versus Reduced-Intensity Fludarabine/Busulfan Regimen in Patients with Myelodysplastic Syndrome Undergoing Allogeneic Hematopoietic Stem Cell Transplantation

Maintenance with Hypomethylating Agents after Allogeneic Stem Cell Transplantation in Acute Myeloid Leukemia and Myelodysplastic Syndrome: A Systematic Meta-Analysis

▪Background: After allogeneic hematopoietic stem cell transplantation (allo-SCT), 35%-45% of patients suffer disease relapse, resulting in dismal outcomes. Several strategies have been adopted to prolong disease-free intervals. Hypomethylating agents (HMA) seem to have a range of properties favorable to post-allo-SCT maintenance. They mediate a direct anti-leukemic effect in acute myeloid leukemia (AML) and myelodysplastic syndrome (MDS), regardless of their molecular mutation profile. Moreover, their abilities to induce a CD8+ tumor-specific T cell response, together with the expansion of regulatory T cells, leads to an epigenetically enhanced graft-versus-leukemia effect that is not counterbalanced by an increased risk of graft-versus-host disease (GVHD).Materials and Methods: Two investigators independently searched the Embase and MEDLINE databases for relevant studies published from inception to 31 January 2021. The inclusion criteria were as follows: (1) the studies had to be either randomized controlled trials or cohort studies; (2) the patients underwent allo-SCT for AML or MDS; (3) the studies compared 2 patient groups: one receiving HMA maintenance post-allo-SCT, and the other being an observational group; and (4) the studies needed to report at least one of our primary outcomes of interest; overall survival (OS), relapse-free survival (RFS), grade II-IV acute GVHD, and chronic GVHD.Results: Eleven eligible studies compared HMA maintenance to observation following allo-SCT for AML or MDS. The OS of the HMA maintenance group was superior to the observation group, with a pooled odds ratio (OR) of 2.52 (95% CI, 1.60-3.94; I 2, 51%; Figure 1A). Similarly, a pooled meta-analysis found that the RFS was significantly better for patients receiving HMA maintenance, with a pooled OR of 2.64 (95% CI, 1.79-3.90; I 2, 0%; Figure 1B). Moreover, the cumulative incidence of relapse (CIR) was significantly lower in patients who received HMAs. The HMA group also had lower non-relapse mortality (NRM) compared with the observation group. Overall, the incidences of grade II-IV acute GVHD and chronic GVHD did not differ in both groups. However, when looking specifically at those receiving decitabine maintenance, the rate of chronic GVHD seemed to be lower compared with observation alone.Conclusions: The current systematic review and meta-analysis illustrated that AML and MDS patients receiving HMA maintenance after allo-SCT had better outcomes in regards to OS, RFS, NRM, CIR as well as a reduced incidence of chronic GVHD.Figure 1. Forest plots of the meta-analysis of HMA maintenance compared with observation. (A) OS rate. (B) RFS rate. [Display omitted] DisclosuresNo relevant conflicts of interest to declare.

HLA-Matched Related Hematopoietic Stem Cell Transplantation in Adolescents and Adults with Sickle Cell Disease: Comparison of Myeloablative Versus Non Myeloablative Approaches. Report from the Société Francophone De Greffe De Moelle Et De Thérapie Cellulaire

IntroductionAllogeneic hematopoietic stem cell transplantation (HSCT) is a curative therapy for sickle cell disease (SCD) allowing a SCD-free survival over 95% among children with matched HLA-identical donor (Gluckman E. Blood, 2017; Bernaudin F. Haematologica, 2020). In adults, myeloablative HSCT is associated with more graft-versus host disease (GVHD) and higher toxicity (Cappelli B. Haematologica, 2019). More recent approaches using non myeloablative (NMA) conditioning regimen (3 gray (Gy) total body irradiation (TBI) plus alemtuzumab) followed by HLA-identical peripheral blood stem cells (PBSC) and post-transplant sirolimus appear safe in adults (Hsieh MM. JAMA, 2014), but incidence of graft failure might be higher than the one reported after myeloablative conditioning (MAC) (Alzahrani M. Br J Haematol, 2021). Here, we compare outcomes after MAC or NMA conditioning regimens in patients over 15 years old transplanted from a matched related donor (MRD).Patients and methodsAll consecutive patients transplanted for SCD from a MRD from January 2015 to October 2020 were eligible if they were over 15 years old and received a busulfan-based MAC conditioning regimen or a NMA conditioning regimen.Chimerism was studied by analyzing various polymorphisms after polymerase chain reaction (PCR) amplification of DNA obtained from whole blood cells. Rejection was defined as donor chimerism <5%. Event-free survival (EFS) was defined as the probability to be alive with blood donor chimerism over 20%.ResultsThirty-four patients were included: 20 in the MAC and 14 in the NMA groups. Median age at transplant was 17 years (range 15-46) without difference between groups. Forty four percent of patients had a history of cerebral vasculopathy, 79% of recurrent vaso-occlusive crises and 76% of acute chest syndrome. ABO major incompatibility was present in 15% of patients. There was no difference in patient characteristics according to the conditioning regimen group except for pre-transplant cerebral vasculopathy, more frequently reported in the MAC group: 70% versus 6% in the NMA group (p<0.001).In the MAC group, conditioning regimen associated busulfan (12.8 mg/kg IV), cyclophosphamide (N=17) or fludarabine (N= 3) and anti-thymoglobulin (ATG, mostly 20mg/kg). Stem cell source was bone marrow and post-transplant immunosuppression combined cyclosporine and mycophenolate or methotrexate. In the NMA group, conditioning regimen associated 3Gy TBI and alemtuzumab (1mg/kg), followed by PBSC and post-transplant sirolimus.All patients engrafted and no secondary graft failure was observed. One MAC group patient died from GVHD. The 2-year overall and EFS were 95% (CI 95%: 85.9-100) in the MAC group (median follow-up of 39 months (range 8-63)) and 100% (CI 95%: 100-100) in the NMA group (median follow-up of 17 months (range 9-39)). Incidence of grade II-IV acute GVHD was 0% in the NMA group versus 20% in the MAC group (p=0.12). Incidence of chronic GVHD was 0% in the NMA group versus 25% in the MAC group (p=0.06). From the 27 patients with follow-up>12 months, 17/17 discontinued immunosuppressive therapy in the MAC group versus 8/10 in the NMA group. Hematopoietic recovery was faster in the NMA group with less platelet and red blood cell units transfused (Table). Throughout the follow-up, median donor chimerism was higher after MAC transplantation than after NMA transplantation: 98% (range 69-100) and 86 % (range 50-97) respectively at 1 year (p=0.017). Donor chimerism remained above 50% throughout the follow-up in all patients except 1 of the NMA group who displayed stable chimerism between 40 and 50%. All patients achieved HbS level close to the one of their donors. There was no difference between the 2 groups regarding occurrence of infections. MAC transplant was more often associated with hypertension, neurological complications, severe mucositis and need of enteral or parenteral nutrition. Moreover, duration of hospitalization was longer in MAC group: 54 days (range 39-192) versus 35 days in the NMA group (range 21-52) (p<0.001) (table).ConclusionIn this series of adolescents and adults transplanted for SCD, the survival without SCD was excellent with a faster hematological recovery and a lower toxicity after NMA HSCT. Longer follow-up is required to confirm stable mixed donor chimerism and the cure of SCD after NMA approach. [Display omitted] DisclosuresJoseph: bluebird bio: Consultancy. Boissel: Servier: Consultancy, Honoraria; JAZZ Pharma: Honoraria, Research Funding; Incyte: Honoraria; Amgen: Consultancy, Honoraria, Research Funding; SANOFI: Honoraria; CELGENE: Honoraria; Novartis: Consultancy, Honoraria, Research Funding; Bristol-Myers Squibb: Honoraria, Research Funding; PFIZER: Consultancy, Honoraria. Pondarré: ADDMEDICA: Honoraria.

Sequential Conditioning Regimen with Thiotepa in Allogeneic Hematopoietic Cell Transplantation for the Treatment of Refractory Myeloid Malignancies

IntroductionThe outcome of conventional allogeneic hematopoietic cell transplantation (HCT) for the treatment of patients with refractory myeloid malignancies remains poor. Thiotepa-based sequential conditioning has shown promising results for various refractory hematological malignancies (Duléry R et al. Biol Blood Marrow Transplant. 2018; 24(5):1013-1021). However, no study has evaluated the outcome of this sequential approach specifically in refractory myeloid malignancies. The optimal dose of chemotherapeutic agents used in the conditioning regimen and the feasibility of this sequential approach in patients aged 60 years and above also need to be assessed.MethodsAll consecutive patients with refractory myeloid malignancy who underwent allogeneic HCT with a thiotepa-based sequential conditioning regimen in Saint Antoine hospital between April 2013 and October 2020 were included. The sequential approach consisted of a broad spectrum cytoreduction with thiotepa, etoposide, and cyclophosphamide (TEC) from day -15 to -10. Then, after a 3-day rest, a reduced-intensity conditioning (RIC) regimen was administered with fludarabine 150 mg/m 2, intravenous busulfan 6.4 mg/kg and thymoglobulin 5 mg/kg from day -6 to -2. From 2013 to 2018, doses of thiotepa (10 mg/kg), etoposide (400 mg/m 2) and/or cyclophosphamide (1600 mg/m 2) could be reduced in patients older than 60 years or with comorbidities. Since September 2018, the use of a reduced TEC-RIC regimen (thiotepa at 5 mg/kg, etoposide 300 mg/m 2 and cyclophosphamide 1200 mg/m 2 from day -13 to -10) became the new standard of care for all patients. After transplant, patients could receive a hypomethylating agent or targeted therapy to prevent relapse. Prophylactic donor lymphocyte infusions were given to enhance the graft-versus-leukemia effect, in the absence of contraindication. Graft-versus-host disease (GVHD) prophylaxis was cyclosporine A and mycophenolate mofetil for all patients. Post-transplant cyclophosphamide was added in the case of haploidentical HCT.ResultsSeventy-one patients (median age 61 years, range 15-76) were included. Diagnoses comprised acute myeloblastic leukemia (n=65) and myelodysplastic syndrome/chronic myelomonocytic leukemia (n=6). Donors were haploidentical (n=36), matched related (n=13), unrelated (n=21) and umbilical cord blood (n=1). A reduced TEC-RIC was administrated to 43 (61%) patients, a full dose TEC-RIC to 18 (25%), and a TEC-RIC with a dose reduction only for thiotepa to 10 (14%). With a median follow-up of 45.4 months (95% CI: 36.7-63.6), the 2-year overall survival (OS), progression-free survival (PFS), and non-relapse mortality (NRM) were 51%, 41%, and 24%, respectively. Patients receiving a reduced TEC-RIC had a lower cumulative incidence of acute and chronic GVHD (acute grade II-IV GVHD: 14%, acute grade III-IV GVHD: 0%, chronic GVHD: 19%) than the other patients (acute grade II-IV GVHD: 29%, acute grade III-IV GVHD: 18%, chronic GVHD: 29%). The outcomes were not significantly different according to the TEC dose in terms of relapse incidence, OS, and PFS, although the NRM was lower with the reduced TEC-RIC (21% versus 28%, p=0.72). Most notably, patients aged 60 years and above had a 2-year OS and PFS of 48% and 39%, respectively, with no significant difference compared to patients younger than 60 years (Figure).ConclusionOur findings endorse the feasibility and efficacy of a thiotepa-based sequential approach for refractory myeloid malignancies undergoing HCT. The dose reduction did not compromise disease control and expanded the transplant option to older patients, ineligible for a higher dose regimen. Thus, a reduced TEC-RIC sequential regimen can be proposed for selected patients older than 60 years and allows promising outcomes for the treatment of refractory myeloid malignancies. [Display omitted] DisclosuresDuléry: Gilead: Other: travel support and meeting fees; Takeda: Consultancy; Novartis: Honoraria. Malard: Therakos/Mallinckrodt: Honoraria; Biocodex: Honoraria; Astellas: Honoraria; JAZZ pharmaceuticals: Honoraria; Sanofi: Honoraria; Janssen: Honoraria. Legrand: Servier: Consultancy. Fenaux: Abbvie: Honoraria, Research Funding; JAZZ: Honoraria, Research Funding; Celgene/BMS: Honoraria, Research Funding; Novartis: Honoraria, Research Funding; Takeda: Honoraria, Research Funding; Janssen: Honoraria, Research Funding; Syros Pharmaceuticals: Honoraria. Labopin: Jazz Pharmaceuticals: Honoraria. Mohty: Sanofi: Honoraria, Research Funding; Pfizer: Honoraria; Novartis: Honoraria; Takeda: Honoraria; Jazz: Honoraria, Research Funding; Janssen: Honoraria, Research Funding; Gilead: Honoraria; Celgene: Honoraria, Research Funding; Bristol Myers Squibb: Honoraria; Astellas: Honoraria; Amgen: Honoraria; Adaptive Biotechnologies: Honoraria.

Post-Transplantation Cyclophosphamide for Graft-Versus-Host Disease Prophylaxis in Allogeneic Hematopoietic Cell Transplantation for Higher-Risk Myelodysplastic Syndrome

Introduction: Allogeneic hematopoietic cell transplantation is an only potentially curative option for patients with higher-risk myelodysplastic syndrome (MDS). Owing to the advances in treatment strategies including reduced intensity conditioning, graft-versus-host disease (GVHD) prevention and supportive care, more elderly patients or those with comorbidities can proceed to allogeneic HCT. However, the long-term survival rate following allogeneic HCT is reported to be less than 50%, and non-relapse mortality (NRM) rate is still high reaching upto 30%. In this study, we aimed to evaluate the feasibility of using post-transplantation cyclophosphamide (PTCy) as a GVHD prophylaxis in allogeneic HCT for higher-risk MDS patients. We also compared the post-transplantation outcomes of PTCy group and those of historical control who received HCT using anti-thymocyte globulin (ATG).Methods: Patients with higher-risk MDS or MDS/myeloproliferative neoplasm (MPN) with bone marrow blast ≥ 5% were included in this study. Higher-risk MDS was defined by MDS with International Prognostic Scoring System >1.0 or bone marrow blast ≥ 5% at any time points before HCT. Conditioning regimen consists of busulfan (4-days for patients aged <55 years, 2-days for 55 years), fludarabine. For GVHD prophylaxis, PTCy (50 mg/kg on days 3 and 4), cyclosporine, and mycophenolate mofetil were administered. In historical group, patients received 2- or 4-days of busulfan, fludarabine, and ATG with short course of methotrexate and cyclosporine.Results: Ninety-two and 144 patients received allogeneic HCT using PTCy and ATG, respectively. The median overall survival were 47.9 and 44.0 months, respectively (P=.383). Cumulative incidence of total and grade II-IV acute GVHD in PTCy and ATG group were 19.6% vs. 37.5% (P=.002), and 2.6% vs. 21.7% (P<.001), respectively. Incidence of total and extensive chronic GVHD (50.0% vs. 49.1%, P=.567; 32.5% vs. 33.4%, P=.581), 1-year NRM (20.8% vs. 22.9%, P=.702), and 2-year relapse (16.0% vs. 18.1%, P=.605) were not different between two groups. Neutrophil and platelet engraftment was significantly faster with ATG than PTCy (median 12 vs. 15 for neutrophil; median 15 vs. 24 days for platelet).Conclusion: Allogeneic HCT using PTCy as GVHD prophylaxis in higher-risk MDS seems feasible in terms of low rate of acute GVHD and relapse incidence. DisclosuresChoi: Ingenium Therapeutics, Daejeon, Korea: Consultancy, Current holder of individual stocks in a privately-held company. Lee: Ingenium Therapeutics, Daejeon, Korea: Consultancy, Current holder of individual stocks in a privately-held company. Lee: Korean Society of Hematology: Membership on an entity's Board of Directors or advisory committees; Astellas Pharma, Inc.: Consultancy, Honoraria, Other: Advisory board; AbbVie: Honoraria, Other: Advisory board.

Encouraging Survival and High Rates of Toxicity: Allogeneic Hematopoietic Cell Transplantation after Anti-CD19 Chimeric Antigen Receptor T-Cell Therapy in Aggressive Lymphoma Patients

BackgroundApproximately 60% of patients with aggressive large B-cell lymphoma (ALBCL) treated with anti-CD19 chimeric antigen receptor T-cell (CAR T) will ultimately progress or relapse. Allogeneic hematopoietic cell transplantation (Allo-HCT) is a potentially curative treatment for lymphoma patients who relapse after CAR T-cell therapy. However, the efficacy and toxicity profile of allo-HCT following CAR T in aggressive lymphoma patients are not well defined. Herein, we report our experience.Methods and patientsA total of 29 adult patients (median age 45 years [IQR 40-55]) who received allo-HCT for ALBCL between 2017 to 2021 were included. All patients were previously treated with anti-CD19 CAR T-cell (academic CD28-costimulatory domain product [n=23, 79%]; tisagenlecleucel [n=6, 21%]). Twenty-five (86%) and 4 (14%) had a diagnosis of DLBCL and PMBCL, respectively. Median number of previous therapies before CAR T was 3 (IQR 2-4). Eight (28%) patients underwent a previous autologous HCT. No patient underwent a previous allo-HCT. Median hematopoietic cell transplantation-specific comorbidity index (HCT-CI) was 3 (IQR 2-3). Six (21%) patients had a Karnofsky performance status ≤ 80%.Allo-HCT was performed at a median of 4.1 months (IQR 2.2-5.4) post CAR T, with the majority of patients (48%) receiving transplant as first-line post CAR T. Reasons for allo-HCT were consolidation of complete response (CR) to CAR T in high-risk disease (n=4, 14 %), partial response (PR) to CAR T (n=7, 24%) and relapse /progression after CAR T (n=18, 62%). Disease response before allo-HCT was CR (n=11, 38%), PR (n=11, 38%) and progressive disease (n=7, 24%). Donors were matched siblings (n=13, 45%), matched unrelated (n=9, 31%) and mismatched unrelated /haploidentical donors (n=7, 24%). Myeloablative and reduced-intensity conditioning regimens were given in 13 (45%) and 16 (55%) patients, respectively. Methotrexate-based graft versus host disease (GVHD) prophylaxis was used in 20 (69%) patients. Antithymocyte globulin and post-transplantation cyclophosphamide were administered in 13 (45%) and 5 (14%), respectively.ResultsMedian follow-up was 33 months (IQR 13-41). Neutrophil engraftment rate was 93% (two early deaths before engraftment due to infection and multi-organ failure). Two-year overall survival (OS) and progression-free survival were 44% (95% CI: 28-68) and 30% (95% CI: 17-55), respectively. Two-year cumulative relapse incidence and non-relapse mortality were 45% (95% CI: 25-63) and 25% (95% CI: 11-43), respectively (Figure). In a univariable Cox regression, factors significantly associated with a shorter OS were number of interim therapies between CAR T and allo-HCT (Hazard ratio [HR] 2.2 [95% CI: 1.3-3.9], p 0.006) and the length of time between CAR T and allo-HCT (HR 3.8 [95% CI: 1.2-12.1], p 0.02). Best response to CAR T and disease response before allo-HCT were not significant risk factors for a shorter OS.High rates of grade ≥ 3 hyperbilirubinemia (total bilirubin >3 ULN) and hepatic sinusoidal obstruction syndrome (SOS) were observed in 10 (35%) and 5 (17%) patients, respectively. These liver insults were not contributed to acute GVHD. All patients with SOS were treated with defibrotide and two patients died from related complications. Interestingly, 4/5 patients with SOS were conditioned with fludarabine and thiotepa.One-year cumulative incidence of grade II-IV acute GVHD was 34% (n=10; 95% CI: 18-52). Notably, 6 patients had grade IV acute GVHD, 4 of them were refractory to corticosteroids and 3 patients died due to acute GVHD. Two-year cumulative incidence of chronic GVHD was 23% (n=5; 95% CI: 7-46). Chronic GVHD was considered extensive in 4 of them.Bloodstream bacterial infection was documented in 11 (38%) patients. Invasive fungal infection occurred in 6 (21%) patients and included brain aspergillosis, cutaneous aspergillosis, 2 lung aspergillosis, hepatosplenic candidiasis and an ocular mucor mycosis.ConclusionAllogeneic hematopoietic cell transplantation is feasible after failure of CAR T-cell therapy in aggressive lymphoma, although with a relatively high rate of SOS and severe acute GVHD in these heavily pretreated patients. Overall survival is encouraging with approximately 30% of patients remaining alive and disease-free at two years. Larger scale studies are required to better define the role of allo-HCT in this setting. [Display omitted] DisclosuresShouval: Medexus: Consultancy. Jacoby: NOVARTIS: Honoraria, Membership on an entity's Board of Directors or advisory committees. Avigdor: Takeda: Consultancy, Honoraria; Janssen: Research Funding; BMS: Research Funding; Gilead: Consultancy, Honoraria; Pfizer: Consultancy, Honoraria.

Predictive Factors and Outcomes after Allogeneic Stem-Cell Transplantation for Adults with Acute Lymphoblastic Leukemia in Brazil

Introduction: Allogeneic stem-cell transplantation (HSCT) remains a potentially curative approach for acute lymphoblastic leukemia (ALL), especially for high-risk patients and those with relapsed/refractory disease, although its efficacy is offset by a not negligible toxicity. Adult patients with ALL fare worse in developing countries with low data about the HSCT in this setting. In this study, we aim to describe outcomes and examine risk factors for overall survival (OS), disease-free survival (DFS), cumulative incidence of relapse (CIR), non-relapse mortality (NRM) and graft-versus-host disease (GVHD) after HSCT for ALL in Brazilian centers.Methods: This is a retrospective registry study. Patients with ALL or ambiguous lineage leukemia above 16 years who underwent a first HSCT in 5 Brazilian centers between January 2007 and December 2017 were included. Kaplan-Meier method and competing risk analysis were used. Multivariable analysis (MVA) was performed using Cox regression and the Akaike's information criteria was used for model selection. Cut-offs for continuous variables were calculated through “findcut” R function. Center effect was evaluated by using frailty model.Results: Overall, 275 patients were included with a median age of 31y (range, 16-65). Philadelphia chromosome was found in 35%. Baseline characteristics are summarized in Table 1. Matched sibling donor (MSD), matched unrelated donor (MUD), mismatched unrelated donor (MMUD), haploidentical donor and umbilical cord were reported in 53%, 19%, 9%, 19%, and 5%, respectively. Total body irradiation (TBI) was used in 67% of myeloablative HSCT. Median time to HSCT in CR1 was 7.8 months. Engraftment failure rate was 1.5%. Median follow-up time was 6.4 y. Cumulative incidence of acute grade II-IV and chronic GVHD were 54.2% and 26.2%, respectively. In MVA, the use of MUD (HR=2.3) and increased donor age (HR=1.02) were associated with GVHD. Five-year CIR was 28.1% (95% CI 22.9-33.6) and 5-y NRM was 34.1% (95% CI 28.4-39.8). At D+100, NRM incidence was 22.6%. Central nervous system involvement at the diagnosis (HR=2.2), and disease status (HR 1.8 for CR2+, and HR 7.9 for refractory) increased relapse incidence, whereas the use of peripheral blood graft (HR=0.51) and haploidentical donor (HR=0.4) significantly decreased relapse incidence. In MVA, NRM was increased by patient's age (HR=1.04), refractory status (HR=4.2), MUD (HR=3.8) and donor age (HR=1.02). Center effect was significantly associated with relapse and NRM. Five-year OS and DFS were 40.7% (95% CI 35.1-47.1) and 37.8% (95% CI-32.3-44.1), respectively (Figure 1). Patient's age, donor age and disease status were independently associated with OS and DFS (Table 2). When GVHD (as a time-dependent variable) was introduced in the MVA for OS and DFS, it was associated with decreased OS (HR 4.2, p<0.001) but not with DFS. Pre-HSCT positivity of minimal residual disease (>0.01%) was associated with worse DFS in univariate analysis (HR=1.47) in available cases.Conclusions: This is the largest series of ALL adults receiving HSCT from Brazil. While OS and DFS were similar to published data, NRM was higher. Patient's age and donor age outweighed donor type or graft source in our analysis. Interestingly, haploidentical HSCT related to lower CIR, whereas the use of MUD was associated with higher NRM and GVHD rates. These results impact on donor selection strategy in our country, aiming to timely offer HSCT for high-risk ALL patients in our setting. [Display omitted] DisclosuresNo relevant conflicts of interest to declare.

Haploidentical Versus Cord Blood Stem Cell Transplantation As the Second Transplant for Relapsed Acute Myeloid Leukemia Patients after the First Stem Cell Transplantation

Haploidentical Versus Cord Blood Stem Cell Transplantation As the Second Transplant for Relapsed Acute Myeloid Leukemia Patients after the First Stem Cell Transplantation

Excellent Outcomes of the Second Allogeneic Hematopoietic Stem Cell Transplantation in Hematological Malignancies with Reduced Toxicity Conditioning and Donor Change

Introduction: High relapse rate and transplant-related mortality (TRM) are the major obstacles for the second allogeneic hematopoietic stem cell transplantation (allo-HSCT). Reduced-toxicity conditioning (RTC) can decrease TRM and healthier donor may provide stronger anti-leukemia and anti-infection effects.Objective:In current clinical study, the safety and efficacy of the second allo-HSCT with RTC and donor change were examined.Methods: Between April 2018 and June 2021, total 48 patients with hematological malignancies (B-ALL 26, T-ALL/LBL 4,AML16,MDS 2) who failed to the first allo-HSCT(relapsed 47, secondary rejection 1) and underwent the second allo-HSCT in our hospital were enrolled. The median age was 25(5-55) years old. Male to female was 25:23. Before the second allo-HSCT, 35 (72.9%) patients were in complete remission (CR) (minimal residual disease (MRD) negative in 28, MRD positive in 7), and 13 (27.1%) cases (B-ALL7,T-ALL/LBL2,AML3,MDS1) in non-remission(NR). The median interval between twoallo-HSCTs was 19.5 (8-77) months. For better donor selection, the functions of hematopoiesis and immune (subsets of lymphocyte, immune globulin,and granzyme and perforin of NK cell) as well as hematological and immunological hereditary predisposition gene variants for potential donors were tested. The types of the first allo-HSCT included haploidentical (n=33), unrelated (n=8), identical sibling (n=5), and unrelated cord blood (n=2). All donors were changed for the second allo-HSCT(haploidentical 35, unrelated 13)except one recipient no other donor available. RTC regimens were mainly total body irradiation(TBI)/fludarabine (FLU)-based(n=39) or busulfan (BU)/FLU-based (n=7).Two patients were with total marrow irradiation (TMI)/FLU-basedregimen. For TBI/FLU regimen, fractionated TBI (8Gy in 32, 10Gy in 7), cytarabine 1-2g/m 2 for 3 days,FLU 30mg/m 2 for 5 days, Me-CCNU 250mg/m 2 for 1 day, and ATG were used. For BU/FLU regimen, BU 0.8mg/kg q6h for 3 days, cytarabine 1-2g/m 2 for 3 days,FLU 30mg/m 2 for 5 days, Me-CCNU 250mg/m 2 for 1 day, and ATG were used. For TMI/FLU regimen, the same conditioning as TBI/FLU was used except fractionated TMI 10-12Gy instead of TBI. Decitabine (20mg/m 2, 3 days) or etoposide (200mg/m 2, 2 days) were administrated in some patients in NR or MRD positive. Cyclosporine, mycophenolate mofetil and short-term methotrexate were employed for graft-versus-host disease (GVHD) prophylaxis. Some patients received maintenance therapy post-transplant with targeted medicine based on their fusion genes or gene mutations.Results: ALL patients became full donor chimerism. The median time for neutrophil and platelet recovery was 15 (11-22) days and 16 (10-240) days. The incidences of grade II-IV acute GVHD (aGVHD) and chronic GVHD(cGVHD) were 18.8%, 47.5% (limited 25%, extensive 22.5%), respectively. The incidences of CMV and EBV reactivation were 31.3% and 6.3%. No severe hemorrhagic cystitis occurred. The median follow-up was 13(1-38) months. One-year disease-free survival (DFS) and overall survival (OS) of all patients were 68.7% (95% CI:0.511;0.811) and 78.9% (95% CI:0.62;0.889) . Nine patients died(relapse 7,GVHD and infection 2).The relapse rate was 22.9%.TRM was only 4.2%. NR before transplant and TP53 mutation were high risk for disease recurrence post-HSCT. Relapse rates were 53.8% vs. 11.4% in NR and CR patients, and 50% vs. 17.5% in the patients with or without TP53 mutation. Disease status before transplant was key impact factor for survival after the second allo-HSCT. One-year OS in CR and NR settings were81.4 % and 70%, respectively, p=0.13. One-year DFS in CR and NR settingswere79.6%, and 41.9%, respectively, p=0.005. No significant difference of DFS was seen in haploidentical and unrelated transplants(68.1% vs.71.8%, p=0.627).Conclusions: With our strategy of RTC regimens and donor change, excellent outcomes of the second allo-HSCT in hematological malignancies have been achieved. One-year DFS and OS are 68.7% and 78.9%. Both TRM and relapse rate are low (4.2%, 22.9%). The most important factor on prognosis of the second allo-HSCT is disease status before transplant but not donor type. TP53 mutation also has negative impact on DFS after the second allo-HSCT. DisclosuresNo relevant conflicts of interest to declare.

Outcome of Allogeneic HSCT after Chemo-Based Conditioning in Infants with Acute Myeloid Leukemia in First Complete Remission: A Multicenter EBMT-PDWP Study

Background: Pediatric patients younger than two years of age with acute myeloid leukemia (AML) commonly receive a chemotherapy-based myeloablative conditioning regimen before allogeneic hematopoietic stem cell transplantation (HSCT). The optimal choice of cytotoxic agents is still controversial.Methods: A retrospective EBMT-registry based study was conducted to investigate the impact of different chemotherapy-based conditionings on the outcomes in young children. Children younger than two years of age receiving a first HSCT of bone marrow (BM), peripheral blood stem cells (PBSC) or cord blood (CB) from matched siblings (MSD) or unrelated donors (UD) in first complete remission (CR1) between 2000 and 2019 were included. Busulfan/Cyclophosphamide (BuCy) and BuCy/Melphalan (BuCyMel) were the most frequent combinations on which this analysis focused. The primary endpoint was leukemia-free survival (LFS). Multivariate analysis adjusting for differences between the conditioning regimens and risk factors influencing outcome was performed using the Cox's proportional hazards regression model.Results: 289 patients (56% male) transplanted at a median age of 1.2 years (IQR 0.9-1.6) after BuCy (164, 57%) or BuCyMel (125, 43%) were included. 184 (64%) patients received BM, 71 (24%) CB and 34 (12%) PBSC from UD (201, 70%) and MSD (88, 30%). In-vivo T-cell-depletion (TCD) was performed in 160 (58%, missing data 14) of the HSCTs with anti-thymocyte-globulin (ATG, 153) or alemtuzumab (7). Ex-vivo TCD was performed in 13 (5%, missing data 3) of the HSCTs. Graft-versus-host-disease (GvHD)-prophylaxis was Cyclosporin-A-based in 90% of the HSCTs. Median follow-up (FU) was 4.9 years (95% CI 3.9-5.5).After a median FU of 4 years, 4-y-LFS after BuCyMel (74.3%, 95% CI 65.1-81.4) was significantly better compared to BuCy (59.7%, 95% CI 51.2-67.2), hazard ratio (HR) 0.56 (95% CI 0.35-0.90, P=0.02). Overall survival (4-y-OS) after BuCyMel (77.2%, 95% CI 68.1-84.0) was significantly better compared to BuCy (66.6%, 95% CI 58.0-73.8), HR=0.58 (95% CI 0.35-0.97, P=0.04).No significant differences were found in the probability of relapse (4-y-RI (whole cohort) 26.2% (95% CI 21.0-31.7), HR of BuCyMel 0.59 (95% CI 0.34-1.02), P=0.06), non-relapse mortality (4-y-NRM (whole cohort) 7.8% (95% CI 5.0-11.4), HR of BuCyMel 0.49 (95% CI 0.19-1.24), P=0.13) and incidence of acute grade II-IV GvHD at day 100 (day-100-aGvHD II-IV (whole cohort) 36.8% (95% CI 31.2-42.5), HR of BuCyMel 0.59 (95% CI 0.35-1.01), P=0.06). Incidence of chronic GvHD (4-y-cGvHD (whole cohort)) was 9.8% (95%-CI 6.3-14.2). The donor type had no significant influence on the outcome.Conclusion: Bu-based conditionings of HSCT for infants with AML at high risk of relapse offer a high probability of cure. Conditioning with three alkylators (BuCyMel) resulted in better LFS and OS compared with two alkylators (BuCy) without significantly increasing the risk of both NRM and aGvHD. Future trials will evaluate the impact of the more recently introduced alkylator Treosulfan within the conditioning of HSCT in pediatric AML. DisclosuresPeters: Amgen: Membership on an entity's Board of Directors or advisory committees, Other: Travel grants. Locatelli: Amgen: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Novartis: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Miltenyi: Speakers Bureau; Medac: Speakers Bureau; Jazz Pharamceutical: Speakers Bureau; Takeda: Speakers Bureau. Moraleda: Pfizer: Other: Educational Grants, Research Funding; Sanofi: Other: Educational Grants, Research Funding; MSD: Other: Educational Grants, Research Funding; ROCHE: Consultancy, Honoraria, Other: Educational Grants, Research Funding; Takeda: Consultancy, Honoraria, Other: Educational Grants, Research Funding; Sandoz: Consultancy, Honoraria; Novartis: Consultancy, Honoraria, Other: Educational Grants, Research Funding; Gilead: Consultancy, Honoraria, Other: Educational Grants, Research Funding; Jazz Pharmaceuticals: Consultancy, Honoraria, Other: Educational Grants, Research Funding; NovoNordisk: Other: Educational Grants, Research Funding; Janssen: Other: Educational Grants, Research Funding; Celgene: Other: Educational Grants, Research Funding; Amgen: Other: Educational Grants, Research Funding. Biffi: BlueBirdBio: Consultancy, Other: Advisory Board. Corbacioglu: Gentium/Jazz Pharmaceuticals: Consultancy, Honoraria.

Outcomes with Mismatched Unrelated Donor Allogeneic Hematopoietic Stem Cell Transplantation: A Systematic Review and Meta-Analysis

BackgroundAllogeneic hematopoietic stem cell transplantation (HCT) is the optimal and potentially curative therapy in various high-risk hematologic malignancies. Although a human leukocyte antigen (HLA)-matched sibling or unrelated donor is a clinically preferred stem cell source, the use of haploidentical family donors and umbilical cord blood HCT now offers the option of HCT in patients lacking a matched donor. However, many patients lack an appropriate donor, in particular the ethnic minorities. Mismatched unrelated donors (MMUD) have historically been utilized as alternative donor source for these patients due to ease of donor availability but is associated with increased risk of graft versus host disease (GVHD) and non-relapse mortality (NRM). In this systematic review and meta-analysis, we aimed to assess the outcomes with MMUD HCT.Methods:Following the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines, a comprehensive literature search was performed on three databases (PubMed, Cochrane Library, and ClinicalTrials.gov) from date of inception through February 2021 using the MeSH and entry terms for “hematopoietic stem cell transplantation”, OR “hematologic neoplasms”, AND unrelated donors“ AND ”treatment outcome“. A total of 2477 records were identified and primary and secondary screening was done. After excluding review, duplicate, and non-relevant articles, we included 13 studies (11 retrospective, 2 prospective) reporting outcomes following MMUD HCT. The Joanna Briggs Institute (JBI) critical appraisal checklist for studies reporting prevalence data and randomized control trial was used for quality assessment, and all studies were reported as good. Proportions along with a 95% confidence interval (CI) were extracted to compute pooled analysis using the ‘meta’ package by Schwarzer et al. in the R programming language (version 4.16-2). The variance between the studies was calculated using Der Simonian-Laird Estimator.Results:We identified 2588 patients from 13 included studies who had MMUD HCT. (Table 1) Median age was 51.7 (18-76) years and 52% (n=1347) were males. Source of primary graft was bone marrow (BM) in 19% (n=478/2508) and peripheral blood (PB) in 81% (n=2030/2508) HCT recipients. Median time to transplant was 10.45 (1.5-139.6) months and median follow up was 41.5 (0.4-136.5) months. Reduced intensity conditioning (RIC) conditioning was used for 73% (n=1884) of the patients while 27.2% (n= 704) patients received myeloablative conditioning (MAC). We estimated a pooled overall survival (OS) of 59% (95% CI 0.52-0.66, I 2 = 92%, n=2563) at one year and 44% (0.36-0.53, I 2=92%, n=1972) at three years. The pooled incidence of acute GVHD (grade II-IV), acute GVHD (grade III-IV), and chronic GVHD were 39% (95% CI 0.33-0.44, I 2=84%, n=2282), 19% (95% CI 0.15-0.23, I 2=65%, n=1417), and 38% (95% CI 0.32-0.47, I 2=93%, n=2477) respectively. Progression free survival (PFS) was 39.5% (95% CI 0.31-0.48, I 2=94% n=2505). The pooled incidence of relapse rate (RR) and NRM were 31% (95% CI 0.25-0.38, I 2=90%, n=2482) and 27% (95% CI 0.21-0.34, I 2 =90% n=2448) respectively.Conclusion:Mismatched unrelated donor HCT has shown favorable outcomes with acceptable toxicity profile. MMUD HCT represents a promising option for patients lacking an HLA-matched donor and has expanded access to HCT in patients with ethnic minorities who often lack a matched donor. [Display omitted] DisclosuresAbhyankar: Incyte/Therakos: Consultancy, Research Funding, Speakers Bureau. McGuirk: Juno Therapeutics: Consultancy, Honoraria, Research Funding; Fresenius Biotech: Research Funding; Novartis: Research Funding; Gamida Cell: Research Funding; Magenta Therapeutics: Consultancy, Honoraria, Research Funding; Pluristem Therapeutics: Research Funding; Allovir: Consultancy, Honoraria, Research Funding; EcoR1 Capital: Consultancy; Kite/ Gilead: Consultancy, Honoraria, Other: travel accommodations, expense, Kite a Gilead company, Research Funding, Speakers Bureau; Astelllas Pharma: Research Funding; Bellicum Pharmaceuticals: Research Funding; Novartis: Research Funding.

Outcomes with Mismatched Unrelated Donor Allogeneic Hematopoietic Stem Cell Transplantation Following Reduced Intensity Conditioning: A Systematic Review and Meta-Analysis

Background:Allogeneic hematopoietic cell transplantation (HSCT) is often the optimal and only potentially curative therapy in several high-risk hematologic malignancies. Although human leukocyte antigen (HLA)-matched donors remain the preferred choice for HSCT recipients, haploidentical and umbilical cord blood HSCT has increased access to transplantation. Despite these advances, many patients lack an appropriate donor, in particular the ethnic minorities. The use of mismatched unrelated donors (MMUD) has increased over the years but concerns regarding increased risk of graft versus host disease (GVHD) and non-relapse mortality (NRM) limits the utility of MMUD HSCT. The intensity of the conditioning regimen has a significant impact on survival in case of mismatched donors. We conducted a systematic review and meta-analysis aimed to investigate the outcomes with MMUD HSCT using reduced intensity conditioning (RIC).Methods:Following the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines, a comprehensive literature search was performed on three databases (PubMed, Cochrane Library, and ClinicalTrials.gov) from date of inception through February 2021 using the MeSH and entry terms for “hematopoietic stem cell transplantation”, OR “hematologic neoplasms”, AND unrelated donors“ AND ”treatment outcome“. A total of 2477 records were identified and primary and secondary screening was done. After excluding review, duplicate, and non-relevant articles, we included 6 (4 retrospective, 2 prospective) studies reporting outcomes following RIC MMUD HSCT. The Joanna Briggs Institute (JBI) critical appraisal checklist for studies reporting prevalence data and randomized control trial was used for quality assessment, and all studies were reported as good. Proportions along with a 95% confidence interval (CI) were extracted to compute pooled analysis using the ‘meta’ package by Schwarzer et al. in the R programming language (version 4.16-2). The variance between the studies was calculated using Der Simonian Laird Estimator.Results:We identified 895 participants in the 6 studies, who had MMUD HSCT with RIC. (Table 1) Median age was 57.5 (18-76) years and 56% (n= 415) were males as reported by four studies (n=740). In five studies with available data (n=855), source of the primary graft was peripheral blood (PB) and bone marrow (BM) in 72% (n=614) and 28% (n=241) of the HSCT recipients respectively. After a median follow-up of 48 (3-125) months, we estimated a pooled overall survival (OS) of 62% (95% CI 0.52-0.72, I 2=84%, n=895) at one year and 43.5% (95% CI 0.33-0.54, I 2 =84% n=855) at three years. The pooled incidence of acute GVHD (grade II-IV), acute GVHD (grade III-IV), and chronic GVHD were 37% (95% CI 0.26-0.49, I 2=81%, n=610), 16% (95% CI 0.07-0.29, I 2=87%, n=542), and 28% (95% CI 0.13-0.47, I 2=95%, n=848) respectively. Progression free survival (PFS) and relapse rates (RR) were 46% (95% CI 0.30-0.62, I 2=92%, n=814) and 31% (95% CI 0.24-0.39, I 2=65%, n=814) respectively. The pooled incidence of non-relapse mortality (NRM) was 23% (95% CI 0.09-0.40, I 2=91%, n=707). Kasamon et al. and Shaw et al. reported 1-year OS of 75-79% with MMUD HSCT using fludarabine, cyclophosphamide and 2 Gy total body irradiation RIC, bone marrow graft and post-transplant cyclophosphamide, sirolimus and mycophenolate for GVHD prophylaxis.Conclusion:Mismatched unrelated donor HSCT has shown favorable outcomes with reduced intensity conditioning using a post-transplant cyclophosphamide-based regimen, comparable to the historical outcomes with mismatched related donor (haploidentical) HSCT. MMUD HSCT with RIC can be considered in patients lacking an HLA-matched donor. This strategy will expand access to HSCT in patients with ethnic minorities who often lack a matched donor. [Display omitted] DisclosuresMcGuirk: EcoR1 Capital: Consultancy; Allovir: Consultancy, Honoraria, Research Funding; Gamida Cell: Research Funding; Novartis: Research Funding; Kite/ Gilead: Consultancy, Honoraria, Other: travel accommodations, expense, Kite a Gilead company, Research Funding, Speakers Bureau; Astelllas Pharma: Research Funding; Fresenius Biotech: Research Funding; Bellicum Pharmaceuticals: Research Funding; Juno Therapeutics: Consultancy, Honoraria, Research Funding; Novartis: Research Funding; Magenta Therapeutics: Consultancy, Honoraria, Research Funding; Pluristem Therapeutics: Research Funding.

Outcomes with Natural Killer Cells Infusion after Allogeneic Hematopoietic Stem Cell Transplantation: A Systematic Review and Meta-Analysis

Background:Natural killer cells (NK) are known to be the first cells that recover after allogeneic hematopoietic stem cell transplant (HCT). NK cells have anti-leukemic and anti-viral properties and are also implicated in the graft versus leukemia (GVL) effect without causing graft versus host disease (GVHD). There is emerging evidence supporting the use of NK cells post-transplant as adoptive immunotherapy to prevent or treat the relapse of hematologic malignancies. Here, we present a systematic review and meta-analysis aimed to investigate the outcomes with NK cells infusion after HCT.Methods:A detailed literature search was conducted for the systematic review and meta-analysis according to the guidelines mentioned in the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA). Population, intervention, comparison, and outcome (PICO) table was developed and three electronic databases (PubMed, Cochrane Library, and ClinicalTrials.gov) were searched through January 2021 using MeSH terms and keywords for “hematologic malignancy and natural killer cells” and “hematopoietic stem cell transplantation and natural killer cells”. No filters or publication time limits were applied for the search. A total of 988 records were identified through database searching. After excluding duplicates, review, and non-relevant articles, we selected 9 studies that reported outcomes with NK cells infusion after HCT. Quality evaluation was done using the NIH quality assessment tool and Inter-study variance was calculated using the Der Simonian-Laird Estimator. Pooled analysis was done using the ‘meta’ package (Schwarzer et al, R programming language) and proportions with 95% confidence intervals (CI) were computed.Results:We identified 9 studies with a total of 149 participants. Out of these, 53 patients were from 4 studies using NK cells for the treatment of relapsed disease after HCT (therapeutic studies) and 96 patients were from 5 studies using NK cells to prevent relapse after HCT (pre-emptive studies).Therapeutic use of NK cells for relapsed disease after HCT: A total of 53 patients from 4 studies were evaluated. The median age of patients was 44.5 (1.9-69) years, and 40% patients were male. The median follow-up was 20 (1-69) months. Overall survival (OS) was reported by two studies at 2 years and was 36.3% and 55%. The pooled complete response (CR) was 18% (95% CI 0.06-0.33, I 2 =0%, n=37) and overall response rate (ORR) was 45% (95% CI 0.20-0.71, I 2 =71%, n=53). The pooled relapse rate was 65% (95% CI 0.32-0.92, I 2 =75%, n=42). The pooled incidence of acute GVHD and chronic GVHD was 15% (95% CI 0.03-0.31, I 2 =41%, n=53) and 8% (95% CI 0.01-0.18, I 2 =0%, n=53) respectively.Pre-emptive use of NK cells to prevent relapse after HCT: A total of 96 patients from 5 studies were evaluated. The median age of patients was 33.5 (2-75) years, and 48% patients were males. The median follow-up was 23.1 (8-81.6) months. The median OS was 1 (0.63-5) years. The pooled CR was 45% (95% CI 0.21-0.70, I 2 =76%, n=83) and ORR was 89% (95% CI 0.57-1.00, I 2 =77%, n=42). The pooled relapse rate was 35% (95% CI 0.20-0.52, I 2 =55%, n=96). The pooled incidence of acute GVHD and chronic GVHD was 30% (95%CI 0.14-0.48, I 2 =61%, n=96) and 8% (95%CI 0.00-0.24, I 2 =73%, n=96) respectively.Conclusion:Infusion of NK cells after HCT to prevent relapsed disease results in favorable outcomes with an acceptable toxicity profile. Optimal use of NK cells infusions after HCT is in a pre-emptive fashion to prevent relapsed disease and the efficacy of NK cells infusions after HCT in the setting of overt hematologic relapse is modest. Our findings suggest the need for large prospective clinical trials to establish the potential benefit of NK cells infusion after HCT to prevent relapse of hematologic malignancies without increased non-relapse mortality. [Display omitted] DisclosuresAbhyankar: Incyte/Therakos: Consultancy, Research Funding, Speakers Bureau. McGuirk: Bellicum Pharmaceuticals: Research Funding; Gamida Cell: Research Funding; Novartis: Research Funding; Novartis: Research Funding; EcoR1 Capital: Consultancy; Fresenius Biotech: Research Funding; Astelllas Pharma: Research Funding; Magenta Therapeutics: Consultancy, Honoraria, Research Funding; Juno Therapeutics: Consultancy, Honoraria, Research Funding; Allovir: Consultancy, Honoraria, Research Funding; Pluristem Therapeutics: Research Funding; Kite/ Gilead: Consultancy, Honoraria, Other: travel accommodations, expense, Kite a Gilead company, Research Funding, Speakers Bureau.

Graft-versus-host disease in patients treated with allogenic hematopoetic cell transplantation: experience from North Macedonia

Introduction: Graft-versus-host disease (GvHD) is the major complication arising after allogeneic hematopoietic cell transplantation (allo-HCT). It can be presented as acute and/or chronic GvHD. The purpose of this study was describe the incidence of acute and chronic GvHD in patients treated with allo-HCT. Materials and methods: This study was designed as a retrospective study, which included 65 patients treated with allogeneic transplantation from human leukocyte antigen identical donor at University Clinic of Hematology in Skopje, North Macedonia. Results: Acute GvHD (aGvHD) was observed in 28 patients, with the most common localization on the skin (75%). Post-transplant phase had significant effect on the frequency of skin aGvHD ( p =0.038). Also statistically significant difference was confirmed between patients with and without acute skin GvHD in terms of conditioning regimen ( p =0.034). Chronic GvHD (cGvHD) was diagnosed in 10 patients, mostly progressing from the previous acute GvHD (9.23%). Post-transplant phase had also significant effect on the frequency of skin cGvHD ( p =0.018). Patients with higher European Society for Blood and Marrow Transplantation risk score had significantly more frequent skin cGvHD than the others. Conclusions: Acute and chronic GvHD were one of the main causes of morbidity and mortality of patients after aloo-HCT. GvHD remains a major risk for patients with allo-HCT regardless of diagnosis and type of transplantation.

Haploidentical transplantation is feasible and associated with reasonable outcomes despite major infective complications–A single center experience from India

Haploidentical stem cell transplantation (SCT) using post-transplantation cyclophosphamide for graft-versus-host disease (GVHD) prophylaxis is a reasonable therapeutic option for patients who do not have a matched sibling donor. Between 2010 and June 2020, 257 patients underwent 269 Haploidentical transplantations, including 122 children. Indications included both malignant (56.8%) and non-malignant (43.2%) diseases. Conditioning regimens included both myeloablative (57.6%) and nonmyeloablative regimens (42.4%). Peripheral blood stem cells were the predominant graft source (96.2%). Based on the disease risk index, patients were classified into early-, intermediate-, and late-stage disease. Engraftment was seen in 205 patients (76.2%) whereas 39 (14.4%) died before engraftment and 23 (8.6%) had primary graft failure. The cumulative incidence of grade II-IV acute GVHD was 47.8% with a 23.9% incidence of grade III-IV acute GVHD. Chronic GVHD was seen in 41.9% with a 15.4% incidence of extensive chronic GVHD. More than 90% had at least 1 documented infection with a 44% incidence of bacterial, 71% viral, and 38% fungal infection. The 2-year overall survival is 40.5% ± 3.2% with a higher survival among children (48.2% ± 3.4%) compared to adults (34.2% ± 4.1%). Survival was poor with late-stage disease (23.6% ± 4.3%) compared to early- (62.5% ± 7.5%) and intermediate-stage (50.3% ± 4.3%). Factors adversely affecting survival included older age of patient (P = .007), late disease status (P = .000), nonmyeloablative conditioning regimen (P = .003), bone marrow as graft source (P = .006), presence of acute GVHD (P = .069), primary graft failure (P = .000), and presence of a documented bacterial (P = .000) and fungal infection (P = .000). On multivariate analysis, older age (P = .027), presence of acute GVHD (P = .033), documented bacterial infection (P = .000), documented fungal infection (P = .000) and primary graft failure (P = .012) continued to remain significant. Haploidentical SCT offers a reasonable chance of cure for patients with both malignant and nonmalignant hematological diseases. Strategies to reduce aGVHD and infection related mortality needs to be explored further.© 20XX American Society for Blood and Marrow Transplantation. Published by Elsevier Inc. All rights reserved.

Donor source and post-transplantation cyclophosphamide influence outcome in allogeneic stem cell transplantation for GATA2 deficiency.

GATA2 deficiency was described in 2011, and shortly thereafter allogeneic hematopoietic stem cell transplantation (HSCT) was shown to reverse the hematologic disease phenotype. However, there remain major unanswered questions regarding the type of conditioning regimen, type of donors, and graft-versus-host disease (GVHD) prophylaxis. We report 59 patients with GATA2 mutations undergoing HSCT at National Institutes of Health between 2013 and 2020. Primary endpoints were engraftment, reverse of the clinical phenotype, secondary endpoints were overall survival (OS), event-free survival (EFS), and the incidence of acute and chronic GVHD. The OS and EFS at 4 years were 85·1% and 82·1% respectively. Ninety-six percent of surviving patients had reversal of the hematologic disease phenotype by one-year post-transplant. Incidence of grade III-IV aGVHD in matched related donor (MRD) and matched unrelated donor recipients (URD) patients receiving Tacrolimus/Methotrexate for GVHD prophylaxis was 32%. In contrast, in the MRD and URD who received post-transplant cyclophosphamide (PT/Cy), no patient developed grade III-IV aGVHD. Six percent of haploidentical related donor (HRD) recipients developed grade III-IV aGVHD. In summary, a busulfan-based HSCT regimen in GATA2 deficiency reverses the hematologic disease phenotype, and the use of PT/Cy reduced the risk of both aGVHD and cGVHD.

Fludarabine–Cyclophosphamide-Based Conditioning with Antithymocyte Globulin Serotherapy Is Associated with Durable Engraftment and Manageable Infections in Children with Severe Aplastic Anemia

Severe aplastic anemia (SAA) is a bone marrow failure syndrome that can be treated with hematopoietic cell transplantation (HCT) or immunosuppressive (IS) therapy. A retrospective cohort of 56 children with SAA undergoing transplantation with fludarabine–cyclophosphamide–ATG-based conditioning (FluCyATG) was analyzed. The endpoints were overall survival (OS), event-free survival (EFS), cumulative incidence (CI) of graft versus host disease (GVHD) and CI of viral replication. Engraftment was achieved in 53/56 patients, and four patients died (two due to fungal infection, and two of neuroinfection). The median time to neutrophil engraftment was 14 days and to platelet engraftment was 16 days, and median donor chimerism was above 98%. The overall incidence of acute GVHD was 41.5%, and that of grade III-IV acute GVHD was 14.3%. Chronic GVHD was diagnosed in 14.2% of children. The probability of 2-year GVHD-free survival was 76.1%. In the univariate analysis, a higher dose of cyclophosphamide and previous IS therapy were significant risk factors for worse overall survival. Episodes of viral replication occurred in 33/56 (58.9%) patients, but did not influence OS. The main advantages of FluCyATG include early engraftment with a very high level of donor chimerism, high overall survival and a low risk of viral replication after HCT.

Bone Marrow versus Peripheral Blood Grafts for Haploidentical Hematopoietic Cell Transplantation with Post-Transplantation Cyclophosphamide

In the coronavirus disease 19 (COVID-19) pandemic era, the number of haploidentical hematopoietic cell transplantations (HCTs) with peripheral blood (PB) grafts increased significantly compared with HCTs with bone marrow (BM) grafts, which may be associated with adverse outcomes. We compared outcomes of HCT in BM graft and PB graft recipients age ≥18 years with hematologic malignancies who underwent T cell- replete haploidentical HCT and received graft-versus-host disease (GVHD) prophylaxis with post-transplantation cyclophosphamide, tacrolimus, and mycophenolate mofetil. Among the 264 patients, 180 (68%) received a BM graft and 84 (32%) received a PB graft. The median patient age was 50 years in both groups. The majority (n = 199; 75%) received reduced-intensity conditioning. The rate of acute leukemia or myelodysplastic syndrome was higher in the BM graft recipients compared with the PB graft recipients (85% [n = 152] versus 55% [n = 46]; P < .01). The median times to neutrophil and platelet engraftment and the incidence of grade II-IV and grade III-IV acute GVHD (aGVHD) were comparable in the 2 groups. Among the patients with grade II-IV aGVHD, the rate of steroid-refractory aGVHD was 9% (95% confidence interval [CI], 5% to 18%) in the BM group versus 32% (95% CI, 19% to 54%) in the PB group (hazard ratio [HR], 3.7, 95% CI, 1.5 to 9.3; P = .006). At 1 year post-HCT, the rate of chronic GVHD (cGVHD) was 8% (95% CI, 4% to 13%) in the BM group versus 22% (95% CI, 14% to 36%) in the PB group (HR, 3.0; 95% CI, 1.4-6.6; P = .005), and the rate of systemic therapy-requiring cGVHD was 2.5% (95% CI, 1% to 7%) versus 14% (95% CI, 7% to 27%), respectively (HR, 5.6; 95% CI, 1.7 to 18; P = .004). The PB group had a significantly higher risk of bacterial and viral infections, with no appreciable advantage in the duration of hospitalization, immune reconstitution, relapse, nonrelapse mortality, or survival. Our data suggest a benefit of the use of BM grafts over PB grafts for haplo-HCT.

Nonmyeloablative, HLA-Mismatched Unrelated Peripheral Blood Transplantation with High-Dose Post-Transplantation Cyclophosphamide

High-dose post-transplantation cyclophosphamide (PTCy) is an effective platform for prevention of severe graft-versus-host disease (GVHD) after allogeneic bone marrow (BM) transplantation with mismatched unrelated donors (mMUDs). Previous studies evaluating PTCy with mMUDs favored BM allografts over peripheral blood stem cell transplantation (PBSCT) due to concerns that PBSCT may be associated with an increased risk of acute and chronic GVHD. In addition, haploidentical PBSCT is associated with high rates of cytokine release syndrome (CRS), which is another concern with mMUD PBSCT. This study was conducted to determine the feasibility and safety of using mMUD PBSCT with PTCy as GVHD prophylaxis. Patients who received mMUD PBSCT using a PTCy-based GVHD prophylaxis at Johns Hopkins Hospital as part of a prospective clinical trial of mMUD and non-first-degree relative haploidentical transplantation with PTCy (ClinicalTrials.gov identifier NCT01203722) were included. All patients underwent T cell-replete PBSCT between November 2012 and August 2020. Statistical analyses were performed using the Kaplan-Meier method and proportional subdistribution hazard regression model for competing risks. The 29 patients in the study had a median age of 54 years, with 10 patients (34%) age ≥60 years. Nineteen grafts (66%) were matched for 9/10 HLA loci, 6 (21%) were match for 8/10, and 4 (14%) were matched for 7/10. No primary or secondary graft failure occurred. The median time to neutrophil recovery (≥500/µL) was 17 days, and that to platelet recovery (≥20,000/µL) was 28 days. Full donor chimerism was achieved in all patients by day +60. The cumulative incidence (CuI) of grade II-IV acute GVHD at 180 days was 15% (90% confidence interval [CI], 3% to 26%). There were no cases of severe chronic GVHD, 3 cases of mild chronic GVHD, and 1 case of moderate chronic GVHD. The CuI of nonrelapse mortality (NRM) was 7% (90% CI, NA to 18%) at 1 year. Eighteen patients (62%) experienced mild CRS (grade 1-2), and 1 patient (3%) experienced severe CRS (grade 3-5). At 1 year, the CuI of relapse was 29% (90% CI, 8% to 50%), overall survival was 93% (90% CI, 85% to 100%), progression-free survival was 64% (90% CI, 46% to 88%), GVHD-free relapse-free survival was 41% (90% CI, 23% to 73%), and chronic GVHD-free relapse-free survival was 64% (90% CI, 46% to 88%). Our data indicate that mMUD PBSCT using PTCy-based GVHD prophylaxis is safe and feasible. All patients engrafted, and rates of NRM (7%) and acute GVHD (15%) at 1 year were low. There was only 1 case (3%) of severe CRS. Compared with previously published outcomes, mMUD PBSCT using PTCy-based GVHD prophylaxis has a safety and efficacy profile that may not be different from that of PBSCT from matched donors. These results further solidify that all patients who require blood or BM transplantation should be able to find an acceptable donor.

FLAMSA-Busulfan-Melphalan as a Sequential Conditioning Regimen in HLA-Matched or Haploidentical Hematopoietic Stem Cell Transplantation for High-Risk Myeloid Diseases

Given the poor prognosis of relapsed/refractory myeloid malignancies, the concept of sequential conditioning before allogeneic hematopoietic stem cell transplantation (allo-HSCT) has proven to be an effective approach. We sought to evaluate a sequential scheme combining fludarabine, amsacrine, and cytarabine (FLAMSA) for cytoreduction, followed by reduced-intensity conditioning with busulfan and melphalan (FLAMSA-BuMel), which was designed to be suitable for both HLA-matched and haploidentical HSCT. This single-center retrospective study included 36 adult patients with high-risk myeloid malignancies who underwent allo-HSCT from HLA-matched (n=19) or haploidentical (n=17) donors. Along with the standard prophylaxis for graft-versus-host disease (GVHD), patients with a haploidentical donor received post-transplantation high-dose cyclophosphamide. A post-transplantation consolidation treatment with low-dose 5-azacytidine and prophylactic donor lymphocyte infusions was provided whenever possible. Thirty patients (83%) achieved complete remission on day +30. With a median follow-up of 30.0 months, the 2-year overall survival was 89% in the HLA-matched group versus 34% in the haploidentical group (P=.0018). The 2-year disease-free survival in these 2 groups was 68% and 34%, respectively (P=.013). At 2 years, the probability of relapse was 32% and 20%, respectively, and nonrelapse mortality was 0% and 58%, respectively (P=.0003). The leading cause of death was relapse in the HLA-matched group (3 of 19) and hemorrhagic events (5 of 17) in the haploidentical group, favored by significantly delayed platelet reconstitution and a severe GVHD context. These data confirm the feasibility of FLAMSA-BuMel as a sequential conditioning in allo-HSCT for high-risk myeloid malignancies. The use of bone marrow as the preferred graft source might reduce the incidence of acute GVHD and nonrelapse mortality in the haploidentical transplantation setting.