Haploidentical T Cell–Replete Transplantation with Post-Transplantation Cyclophosphamide for Patients in or above the Sixth Decade of Age Compared with Allogeneic Hematopoietic Stem Cell Transplantation from an Human Leukocyte Antigen–Matched Related or Unrelated Donor

Improving nutritional status after allogeneic stem cell transplantation: results of phase 2 ALLONUT clinical trial

Malnutrition increases the risk of non-relapse mortality after allogeneic stem cell transplantation (aHSCT). Here are the results of the ALLONUT clinical trial designed to improve the nutritional outcome of patients receiving aHSCT. ALLONUT is a prospective open label phase 2 clinical trial assessing the efficacy of a close tailored nutritional support and management with traditional and original solutions to improve patients nutritional status following aHSCT. Nutritional status evaluation was performed before transplantation, on Day 0, 30, 100 and one year after transplantation. The study involved 70 patients treated by aHSCT. 10% of patients were moderately or severely malnutrition at baseline and 26.9 were severely malnutrition at D30. Patients' nutritional status improved thanks to the cooking classes and the personalized outpatient nutrition program. At D100, 23% were still malnutrition, while only 10.8% were severely malnutrition one year after transplantation. The QLQ-C30 show that quality of life (QoL) decreased until D30, and improve to reach the pre-transplant level on D100 before exceeding it on D360. The study confirmed that a close, personalized nutritional program combining traditional and original measures can improve both nutritional status and QoL for patients suffering from moderate or severe malnutrition after aHCST.

Allogeneic hematopoietic cell transplantation for older patients with AML with active disease. A study from the Acute Leukemia Working Party of the European Society for Blood and Marrow Transplantation (EBMT)

Older adults with acute myeloid leukemia (AML) refractory to initial or reinduction chemotherapy have a dismal prognosis if they do not undergo hematopoietic stem-cell transplantation (HCT). However, data assessing HCT outcomes from different donors are scarce. We evaluated results from a retrospective analysis on patients aged ≥70 years, with AML not in remission who received an allogeneic HCT from HLA-matched sibling donor (MSD), HLA-10/10 matched unrelated donor (MUD), or T-cell replete haploidentical (Haplo) donor, from 2010 to 2021, reported to the ALWP-EBMT database. A total of 360 patients (median age 72 years, range 70-79) were included in the analysis. Median follow-up for the entire population was 35.5 months. Donors were MSD (n = 58), 10/10 HLA-MUD (n = 228), and Haplo (n = 74). A total of 213 (59.2%) patients were primary induction failures, while 147 (40.8%) were in first or subsequent relapse. Graft source was peripheral blood in 92% of the patients. Patients transplanted from Haplo donors more frequently received marrow grafts (p < 0.01) and presented the combination female donor to male recipient (p < 0.01). The overall 2-year rates of overall survival (OS) and leukemia-free survival (LFS) were: 62.4% (95% CI 47.2-74.3) and 47.6% (95% CI 33.1-60.8) for MSD, 43% (95% CI 35.8-49.9), and 37.5% (95% CI 30.7-44.4) for MUD, and 25.9% (95% CI 15.8-37.2), and 26.5% (95% CI 16.3-37.8) for recipients of Haplo transplants. The 2-year cumulative incidence of relapse (RI) was slightly lower for Haplo recipients at 29.6% (95% CI 19-40.9), for MUD it was 30.2% (95% CI 23.9-36.7), and for MSD 34.9% (95% CI 22-48.2); counterbalanced by a higher incidence of non-relapse mortality (NRM) of 43.9% (95% CI 31.6-55.6) for Haplo recipients, 32.2% (95% CI 26-33.1) for MUD and 17.5% (95% CI 8.4-29.3) for MSD. Graft-versus-host disease (GVHD-free, relapse-free survival (GRFS) was 35.3% (95% CI 22.3-48.5) for MSD, 29.6% (95% CI 23.2-36.2) for MUD, and 19.2% (95% CI 10.7-29.6) for Haplo patients. In the multivariate model, compared to the referent group of MSD recipients, the risk of NRM was higher among patients transplanted from Haplo donors ([hazard ratio] HR 5.1, 95% CI 2.23-11.61, p < 0.001) and MUD (HR 3.21, 95% CI 1.48-0.6.94, p = 0.003). Furthermore, both Haplo and MUD were associated with inferior OS, (HR 3.6, 95% CI 1.98-0.6.56, p < 0.001, and HR 2.3, 95% CI 1.37-0.3.88, p = 0.002, respectively), and LFS (HR 2.24, 95% CI 1.31-0.3.84, p = 0.003, and HR 1.64, 95% CI 1.04-0.2.60, p = 0.034, respectively). Patients transplanted from Haplo donors were also associated with worse GFRS (HR 1.72, 95% CI 1.07-2.77, p:0.025) compared with MSD patients. Older adult AML patients with active disease transplanted from MSD experienced prolonged OS and LFS compared to 10/10 MUD and Haplo due to lower NRM. Prospective clinical trials are warranted.

Real-life challenges using personalized prognostic scoring systems in acute myeloid leukemia

Personalized medicine is a challenge for patients with acute myeloid leukemia (AML). The identification of several genetic mutations in several AML trials led to the creation of a personalized prognostic scoring algorithm known as the Knowledge Bank (KB). In this study, we assessed the prognostic value of this algorithm on a cohort of 167 real life AML patients. We compared KB predicted outcomes to real-life outcomes. For patients younger than 60-year-old, OS was similar in favorable and intermediate ELN risk category. However, KB algorithm failed to predict OS for younger patients in the adverse ELN risk category and for patients older than 60 years old in the favorable ELN risk category. These discrepancies may be explained by the emergence of several new therapeutic options as well as the improvement of allogeneic stem cell transplantation (aHSCT) outcomes and supportive cares. Personalized medicine is a major challenge and predictions models are powerful tools to predict patient's outcome. However, the addition of new therapeutic options in the field of AML requires a prospective validation of these scoring systems to include recent therapeutic innovations.

Comparison of haploidentical hematopoietic stem cell transplantation with chemotherapy in older adults with acute myeloid leukemia

Acute myeloid leukemia (AML) outcomes are very poor in older patients. Haploidentical stem cell transplantation (haplo-SCT) helps to achieve long-term survival. However, the benefit of haplo-SCT versus chemotherapy is unclear in older adults with AML. Outcomes were retrospectively compared among patients aged 55‒65 years for chemotherapy consolidation or haplo-SCT for AML in the first complete remission with intermediate to high-risk disease. Forty-six patients who underwent chemotherapy and 38 patients who underwent haplo-SCT were evaluated in the final analysis. Compared with the chemotherapy group, patients in the haplo-SCT group had significantly better overall survival (OS) (74.0% versus 23.9% at 36 months, p = 0.005) and leukemia-free survival (LFS) (74.0% versus 21.6%, p < 0.001). The cumulative incidence of relapse (CIR) was significantly lower in the haplo-SCT group (17.3% versus 75.4%, p < 0.001). Treatment-related mortality (TRM) was similar in the haplo-SCT and chemotherapy groups (7.9% versus 4.8%, p = 0.587). In the multivariate analysis, haplo-SCT was associated with improved OS, LFS, and decreased CIR. Haplo-SCT did not affect TRM. In conclusion, our data suggest that haploidentical transplant may be an alternative to consolidation chemotherapy as post-remission therapy in patients with intermediate or high-risk AML aged 55‒65 years. Further well-designed studies are needed to validate this result.

Comparison of outcomes for HLA-matched sibling and haplo-identical donors in Myelodysplastic syndromes: report from the chronic malignancies working party of EBMT

Myelodysplastic syndromes (MDS) are the second common indication for an Allo-HCT. We compared the outcomes of 1414 matched sibling (MSD) with 415 haplo-identical donors (HD) transplanted with post-transplant cyclophosphamide (PTCy) as GVHD prophylaxis between 2014 and 2017. The median age at transplant with MSD was 58 and 61 years for HD. The median time to neutrophil engraftment was longer for HD being 20 vs 16 days for MSD (p < 0.001). Two-year overall survival (OS) and PFS (progression free survival) with MSD were significantly better at 58% compared with 50%, p ≤ 0.001, and 51% vs 47%, p = 0.029, with a HD. Relapse at 2 years was lower with a HD 23% than with MSD 29% (p = 0.016). Non relapse mortality (NRM) was higher with HD in the first 6 months post-transplant [HR 2.59 (1.5–4.48) p < 0.001] and was also higher at 2 years being 30% for HD and 20% for MSD, p ≤ 0.001. The incidence of acute GVHD grade II-IV and III–IV at 100 days was comparable for MSD and HD, however, chronic GVHD at 2 years was significantly higher with MSD being 44% vs 32% for HD (p < 0.001). After multivariable analysis, OS and primary graft failure were significantly worse for HD particularly before 6 months [HR 1.93(1.24–3.0)], and HR [3.5(1.5–8.1)]. The median age of HD 37 (IQR 30–47) years was significantly lower than sibling donors 56 (IQR 49–62 years) p < 0.001. However, there was no effect on NRM, relapse or PFS. This data set suggests that a MSD donor remains the preferred choice in MDS over a haplo donor. Transplants with haploidentical donors result in satisfactory long-term outcome, justifying it’s use when no better donor is available.

Conditioning Regimens for Frail Patients with Acute Leukemia Undergoing Allogeneic Stem Cell Transplant: How to Strike Gently

Despite the recent dramatic progress in acute myeloid leukemia (AML) and acute lymphoblastic leukemia (ALL) therapy, allogeneic transplant remains a mainstay of treatment for patients with acute leukemia. The availability of novel compounds and low intensity chemotherapy regimens made it possible for a significant proportion of elderly and comorbid patients with AML or ALL to undergo curative treatment protocols. In addition, the expansion of donor availability and the recent dramatic progress in haploidentical stem cell transplant, allow the identification of an available donor for nearly every patient. Therefore, an increasing number of transplants are currently performed in elderly and frail patients with AML or ALL. However, allo-Hematopoietic stem cell transplant (HSCT) in this delicate setting represents an important challenge, especially regarding the selection of the conditioning protocol. Ideally, conditioning intensity should be reduced as much as possible; however, in patients with acute leukemia relapse remains the major cause of transplant failure. In this article we present modern tools to assess the patient health status before transplant, review the available data on the outcome of frail AML an ALL patients undergoing allo-HSCT, and discuss how preparatory regimens can be optimized in this setting.

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.

Clinical Utility of the Detection of the Loss of the Mismatched HLA in Relapsed Hematological Patients After Haploidentical Stem Cell Transplantation With High-Dose Cyclophosphamide

Haploidentical hematopoietic stem cell transplantation (Haplo-HSCT) with high-dose cyclophosphamide (PTCy) has resulted in a low incidence of graft-vs.-host disease (GVHD), graft failure, and non-relapse mortality. However, post-transplantation relapse remains a common cause of treatment failure in high-risk patients. Unraveling the mechanisms of relapse is therefore crucial for designing effective relapse treatment strategies. One of these mechanisms is the loss of the mismatched HLA on the recipient's leukemic cells. To study the incidence and clinical relevance of this phenomenon, we analyzed 181 patients treated with Haplo-HSCT with PTCy (2007–2019), of which 37 relapsed patients after transplantation. According to the kit employed for HLA-loss analysis, among 22 relapsed patients, we identified HLA loss at relapse in 6 of the 22 patients (27%) studied. Based on the results obtained, the genomic loss of HLA was more common in females than males (66 vs. 33%) and HLA-loss relapses occurred later than classical relapses (345 vs. 166 days). Moreover, the patients with HLA-loss had a greater presence of active disease at the time of transplantation and had undergone a larger number of treatment lines than the group with classical relapses (66 vs. 43% and 66 vs. 18%, respectively). Four of these relapses were studied retrospectively, while two were studied prospectively, the results of which could be considered for patient management. Additionally, two relapsed patients analyzed retrospectively had myeloid neoplasms. One patient had not undergone any treatment, and three had undergone donor lymphocyte infusions (DLIs) and chemotherapy. All presented severe GVHD and disease progression. In contrast, the two patients studied prospectively had a lymphoid neoplasm and were not treated with DLIs. One of them was treated with chemotherapy but died from disease progression, and the other patient underwent a second Haplo-HSCT from a different donor and is still alive. We can conclude that the detection of HLA-loss at the onset of relapse after Haplo-HSCT with PTCy could help in clinical practice to select appropriate rescue treatment, thereby avoiding the use of DLIs or a second transplantation from the same donor.

Considerations for haploidentical versus unrelated donor transplants

Haploidentical transplantation is increasingly performed worldwide due to novel methods to control alloreactivity between the donor and recipient. This major advancement has increased donor availability to almost all patients in need. Outcomes with haploidenitcal donors have also improved and prompted many groups to compare outcomes between haploidentical and HLA-matched donor transplants. In this review, we provide a summary of available data on haploidentical transplants performed with post transplant cyclophosphamide-based graft-versus-host disease (GVHD) prophylaxis and HLA-matched unrelated donor transplants.

Haploidentical related donor vs matched sibling donor allogeneic hematopoietic stem cell transplantation for acute myeloid leukemia and myelodysplastic syndrome aged over 50 years: A single-center retrospective study

Allogeneic hematopoietic stem cell transplantation (allo-HSCT) is a potentially curative therapeutic option for patients with acute myeloid leukemia (AML) or myelodysplastic syndrome (MDS). Increasing data suggest that haploidentical donor (HID) transplantation achieve comparable outcomes with HLA-matched sibling donor (MSD) in adult AML/MDS. This retrospective study compared the outcomes of AML or MDS patients age ≥50 years underwent HID and MSD transplantation. One hundred and fifty-six patients were enrolled in this study, including 75 HID and 81 MSD transplantation. The 100-day cumulative incidence of II-IV° acute graft-versus-host disease (GVHD) was 33.3 ± 5.4% vs 22.2 ± 4.6%, respectively, in HID and MSD groups (P = .066), and III-IV° acute GVHD was not significantly different between two groups (5.3%±2.6% vs 6.2%±2.7%, respectively, P = .823). The 2-year cumulative incidence of limited and extensive chronic GVHD was not statistically different in HID and MSD groups (20.9 ± 5.5% vs 18.9 ± 4.8% and 13.0 ± 4.7% vs 19.7 ± 5.0%, P = .889 and P = .269, respectively). The 2-year cumulative incidences of relapse (27.0 ± 5.6% vs 22.7 ± 5.1%, P = .509), 2-year overall survival (63.0 ± 5.8% vs 66.7 ± 5.4%, P = .454), 2-year transplant-related mortality (17.2 ± 4.6% vs 17.4 ± 4.4%, P = .847), 2-year progression-free survival (59.3 ± 5.8% vs 64.5 ± 5.4%, P = .437), 2-year GVHD-free relapse-free survival (42.6 ± 5.9% vs 40.9 ± 5.6%, P = .964) were not significantly different in the two groups. The present data showed equivalent outcomes in AML or MDS patients age ≥50 years underwent HID and MSD transplantation.

Decision Analysis of Transplantation for Patients with Myelodysplasia: "Who Should We Transplant Today?"

PURPOSE OF REVIEW

Myelodysplastic syndrome (MDS) is a heterogeneous hematological disorder characterized by a spectrum of clinical presentation, cytogenetic, and somatic gene mutations and the risk of transformation to acute leukemia. Management options include observation, supportive care, blood transfusion, administration of growth factors and/or hypomethylating agents, and hematopoietic cell transplant (HCT) either upfront or after disease progression.

RECENT FINDINGS

Currently, HCT is the only curative therapy available for patients with MDS, with multiple factors such as donor availability, patient, and disease characteristics being involved in making the decision to proceed with transplant. In this article, we summarize (1) overall prognosis and natural history of MDS, (2) currently available non-HCT therapy with a focus on hypomethylating agents (HMA), (3) outcomes after HCT in patients with MDS, (4) factors to be considered to proceed to HCT for treatment of MDS, and (5) more recent/ongoing studies relevant to HCT decision-making processes.

Current Trends on Hemopoietic Stem Cells

Advances in single-cell technology and genetic mouse models have resulted in the identification of new types of hemopoietic stem cells (HSC), resulting in baffling observations, suggesting a reconsideration of the long-held notion that all hematopoietic cells in the adult are derived from HSCs. The existence of long-lived HSC-independent hematopoiesis has led to the conclusion that despite the single hierarchical differentiation route that generates functional blood types, other differentiation routes exist in-vivo. Heterogeneity in the HSC population and the evolving knowledge around HSC has translated to it's improved application as a therapeutic tool for various blood disorders. The reprogramming of non-hematopoietic somatic and mature blood cells to pluripotency with their subsequent differentiation into hematopoietic stem cells/progenitor cells and the introduction of new generation sequencing holds the potential for the resolution of ambiguities involved in HSC bone marrow transplantation. There is a change in the paradigm for HSC transplantation donor selection. Donor choice favors haploidentical HCT than cord blood. This review provides a general overview of the current events around hemopoietic stem cells, with emphasis on the rising trend of HSC transplantation, especially haploidentical stem cell transplantation.

Risk Factors for Graft-versus-Host Disease in Haploidentical Hematopoietic Cell Transplantation Using Post-Transplant Cyclophosphamide

Post-transplant cyclophosphamide (PTCy) has significantly increased the successful use of haploidentical donors with a relatively low incidence of graft-versus-host disease (GVHD). Given its increasing use, we sought to determine risk factors for GVHD after haploidentical hematopoietic cell transplantation (haplo-HCT) using PTCy. Data from the Center for International Blood and Marrow Transplant Research on adult patients with acute myeloid leukemia, acute lymphoblastic leukemia, myelodysplastic syndrome, or chronic myeloid leukemia who underwent PTCy-based haplo-HCT (2013 to 2016) were analyzed and categorized into 4 groups based on myeloablative (MA) or reduced-intensity conditioning (RIC) and bone marrow (BM) or peripheral blood (PB) graft source. In total, 646 patients were identified (MA-BM = 79, MA-PB = 183, RIC-BM = 192, RIC-PB = 192). The incidence of grade 2 to 4 acute GVHD at 6 months was highest in MA-PB (44%), followed by RIC-PB (36%), MA-BM (36%), and RIC-BM (30%) (P = .002). The incidence of chronic GVHD at 1 year was 40%, 34%, 24%, and 20%, respectively (P < .001). In multivariable analysis, there was no impact of stem cell source or conditioning regimen on grade 2 to 4 acute GVHD; however, older donor age (30 to 49 versus <29 years) was significantly associated with higher rates of grade 2 to 4 acute GVHD (hazard ratio [HR], 1.53; 95% confidence interval [CI], 1.11 to 2.12; P = .01). In contrast, PB compared to BM as a stem cell source was a significant risk factor for the development of chronic GVHD (HR, 1.70; 95% CI, 1.11 to 2.62; P = .01) in the RIC setting. There were no differences in relapse or overall survival between groups. Donor age and graft source are risk factors for acute and chronic GVHD, respectively, after PTCy-based haplo-HCT. Our results indicate that in RIC haplo-HCT, the risk of chronic GVHD is higher with PB stem cells, without any difference in relapse or overall survival.

The number of HLA confirmatory tests during unrelated donor search as a driver for the evaluation of back-up haploidentical donor(s)

INTRODUCTION

the identification of a suitable donor in an appropriate timing represents a crucial step in the preparation of allogeneic stem cell transplantation (HSCT). At our Institution, for patients lacking an HLA-identical sibling, a haploidentical donor is considered in the absence of a 10/10-matched or a one-locus HLA-mismatched unrelated donor (UD), but the optimal timing of work-up of potential familiar haploidentical donor(s) by the Apheresis Team is actually unknown.

PATIENTS & METHODS

we analyzed here n = 167 UD searches launched at our Hospital between July 2013 and July 2018 and looked for any correlation between the number of HLA confirmatory tests received and the final type of donor selected for HSCT, in an attempt to identify those situations where prompt evaluation of haploidentical donor(s) is warranted.

RESULTS

a total of n = 117 transplants were performed and haploidentical HSCTs were n = 16 (14 %). In n = 93 cases (56 %) the number of HLA confirmatory tests received were two; they were one, zero and three for n = 52, n = 14 and n = 8 patients, respectively. Only 5 % of haploidentical donors were used when two confirmation test samples were received whereas this percentage rises to 17 % when only one sample reached the HLA lab. When no confirmation tests were available, haploidentical transplant occurred in 100 % of cases.

CONCLUSIONS

besides the situations with no HLA confirmation tests, the evaluation of any haploidentical donor(s) should be promptly started also when only one HLA confirmatory test is received, in order to optimise the potential work-up process and avoid delay in transplantation.

Haploidentical Stem Cell Transplantation With Posttransplant Cyclophosphamide Therapy vs Other Donor Transplantations in Adults With Hematologic Cancers: A Systematic Review and Meta-analysis

Importance

Use of haploidentical (HAPLO) stem cell transplantation with posttransplant cyclophosphamide is rapidly increasing in adults with hematologic cancers. However, its specific role compared with other transplant strategies has yet to be identified.

Objective

To synthesize the existing evidence regarding outcomes of stem cell transplantations comparing HAPLO stem cell transplantation and posttransplant cyclophosphamide therapy with transplantations from matched related donors (MRDs), matched unrelated donors (MUDs), or mismatched unrelated donors (MMUDs).

Data Sources

PubMed, Cochrane Library, ClinicalTrials.gov, and meeting abstracts were searched for the key words haploidentical and cyclophosphamide from inception through March 1, 2019.

Study Selection

Studies comparing HAPLO stem cell transplantation and posttransplant cyclophosphamide therapy with transplantations from other donors in adults with hematologic cancers were eligible for meta-analysis.

Data Extraction and Synthesis

Pooled odds ratios (ORs) and 95% CIs were calculated using a random-effects model.

Main Outcomes and Measures

Main outcomes were all-cause mortality, nonrelapse mortality, and relapse.

Results

A total of 30 studies including 22 974 participants were analyzed. HAPLO stem cell transplantation with posttransplant cyclophosphamide therapy was associated with increased all-cause mortality compared with MRDs (OR, 1.17; 95% CI, 1.05-1.30), similar all-cause mortality compared with MUDs (OR, 1.06; 95% CI, 0.96-1.18), and reduced all-cause mortality compared with MMUDs (OR, 0.75; 95% CI, 0.61-0.92). Regarding nonrelapse mortality, HAPLO stem cell transplantation with posttransplant cyclophosphamide was associated with worse outcomes compared with MRDs (OR, 1.20; 95% CI, 1.04-1.40) but better outcomes compared with MUDs (OR, 0.75; 95% CI, 0.61-0.92) and MMUDs (OR, 0.51; 95% CI, 0.25-1.02). In terms of relapse, HAPLO stem cell transplantation with posttransplant cyclophosphamide was associated with similar outcome compared with MRDs (OR, 1.01; 95% CI, 0.86-1.17) and MMUDs (OR, 1.06; 95% CI, 0.77-1.47) but showed increased relapse compared with MUDs (OR, 1.20; 95% CI, 1.03-1.40).

Conclusions and Relevance

Results of this meta-analysis suggest that MRDs, if available, remain the optimal donors regarding mortality and HAPLO stem cell transplantation with posttransplant cyclophosphamide may be preferred over MMUDs. Prospective comparisons with MUDs are needed.

Improved survival after offspring donor transplant compared with older aged-matched siblings for older leukaemia patients

Donor selection for older leukaemia patients undergoing haematopoietic cell transplant (HCT) is not well defined: outcomes might be improved with a younger offspring donor rather than an older human leukocyte antigen (HLA)-matched sibling donor (MSD). We extended our multicentre dataset. A total of 185 acute leukaemia patients (≥ 50 years) transplanted in first complete remission who received HCT from offspring (n = 62) or MSD (n = 123) were included. A 1:1 ratio matched-pair analysis was performed. We were able to match 54 offspring with 54 MSD patients. Outcomes were compared between the two matched-pair groups. The cumulative incidence of grade II/IV acute graft-versus-host disease (GVHD) (26% vs. 35%; P = 0·23) and chronic GVHD (37% vs. 24%; P = 0·19) was comparable between groups (MSD vs. offspring). The lower three-year transplant-related mortality (9% vs. 26%; P = 0·023) and relapse incidence (6% vs. 17%; P = 0·066) resulted in higher overall survival (85% vs. 58%; P = 0·003) and leukaemia-free survival (LFS) (85% vs. 56%; P = 0·001) in offspring HCT compared with that in MSD HCT. These data might favour a young offspring over an older MSD in patients >50 years. The current analyses confirm that non-HLA donor characteristics, such as kinship and donor age, rather than HLA disparity, predominantly influence survival in older acute leukaemia patients.

[Haploidentical hematopoietic stem cell transplant: How to choose the best donor? Guidelines from the Francophone Society of Bone Marrow Transplantation and Cellular Therapy (SFGM-TC)]

Haploidentical hematopoietic stem cell transplantation has been growing steadily since 2012. The SFGM-TC has twice published guidelines concerning T-cell repleted haploidentical grafts with high dose cyclophosphamide post-transplantation. The 2013 workshop recommended using the non-myeloablative Baltimore protocol with bone marrow and developed prospective protocols to evaluate these transplantations. The 2015 workshop reported improved results of reduced conditioning regimens in Hodgkin's lymphoma and intensive conditioning in myeloid hemopathies, and a similar outcome with 10/10 HLA matched donor with the same disease-risk score thus raising the question of the qualifier "alternative" for haploidentical transplants. The current work concerns the criteria for selecting the donor. The main criterion remains the absence of anti-HLA antibodies directed against the donor present in the recipient sera (DSA - Donor Specific Antibodies). In case of DSA and in the absence of an alternative donor, desensitization protocols exist. The other criteria are impossible to prioritize: age, sex, CMV, and blood type. The degree of relatedness and the number of HLA incompatibilities do not seem to be a criterion of choice. The 'ideal' donor would be a young man, CMV-matched, without major ABO incompatibility with a marrow transplant. There is insufficient data for the KIR-ligand and NIMA/NIPA mismatch. Peripheral stem cell grafts appear to yield more acute GVHD than bone marrow grafts after intensive conditioning, but with comparable survival rates. Based on the literature review, the comparison of haploidentical with unrelated donors encourages inclusion in existing national protocols randomizing these different donors.

Is a matched unrelated donor search needed for all allogeneic transplant candidates?

Donor availability for allogeneic transplantation remains an important factor in determining outcomes of a successful transplant. We examined outcomes of 242 patients treated over 3 years who had a matched unrelated donor (MUD) search at our institution. One hundred sixty patients (66%) had a 10 of 10 MUD identified, and 85 (53%) proceeded to MUD transplantation. White patients and those with common haplotypes were more likely to have a MUD identified (odds ratio [OR], 7.4 [P < .0001]; OR, 41.6 [P < .0001]), and were more likely to proceed to transplantation with a MUD (OR, 11.2 [P < .0001]; OR, 85.1 [P = .002]). In addition, patients who were newly diagnosed/in remission at the time of MUD search had a higher probability of receiving a transplant (OR, 2.01 [P = .013]) and better progression-free survival (PFS; P < .0001). In multivariate analysis for patients who received a transplant, donor type did not influence PFS at 3 years, which was 40% for MUD and 57% for haploidentical transplants, respectively (hazard ratio, 1.2 [P = .50]). In conclusion, race, haplotype frequency, and disease status at the time of MUD search influence the probability of identifying a MUD and receiving a transplant. Patients with a low likelihood of receiving a MUD transplant may proceed to a haploidentical transplant as soon as indicated, as this approach does not appear to compromise transplant outcomes.

Comparison of the clinical outcomes of hematologic malignancies after myeloablative haploidentical transplantation with G-CSF/ATG and posttransplant cyclophosphamide: results from the Chinese Bone Marrow Transplantation Registry Group (CBMTRG)

This study compared G-CSF/ATG and PTCy in myeloablative haploidentical hematopoietic stem cell transplantation (haplo-HSCT) for hematologic malignancies between January 2013 and March 2018 reporting to the Chinese Bone Marrow Transplantation Registry Group (CBMTRG). For each PTCy, G-CSF/ATG subjects (1:4) were selected using the nested case-pair method. In total, 220 patients including 176 in G-CSF/ATG group and 44 in PTCy group were analyzed. The incidences of 30-day neutrophil engraftment (88.6% vs. 96.6%, P=0.001), 90-day platelet engraftment (84.1% vs. 94.2%, P=0.04), the median time to neutrophil engraftment (17 days vs. 12 days, P=0.000) and platelet engraftment (22 days vs. 17 days, P=0.001) were significantly inferior in PTCy group. The incidences of grades 2-4 and 3-4 acute graft-versus-host disease (GVHD), chronic GVHD and severe chronic GVHD were comparable. Among G-CSF/ATG and PTCy groups, the 3-year progression-free survival, overall survival, cumulative incidences of nonrelapse mortality and relapse was 74.3% vs. 61% (P=0.045), 78.3% vs. 65.2% (P=0.039), 12% vs. 27.3% (P=0.008), and 14.9% vs. 11.7% (P=0.61), respectively. G-CSF/ATG can achieve better engraftment, PFS and OS, and lower incidence of NRM compared to PTCy in myeloablative haplo-HSCT for hematologic malignancies.

Haploidentical Transplantation with Post-Transplant Cyclophosphamide versus Unrelated Donor Hematopoietic Stem Cell Transplantation: A Systematic Review and Meta-Analysis

Hematopoietic stem cell transplantation (HSCT) is the standard treatment for patients with high-risk hematologic malignancies. Only approximately 25% of siblings are HLA-matched, and thus alternative donors-unrelated or haploidentical-are usually the only options available. This meta-analysis aimed to compare haploidentical HSCT with post-transplantation cyclophosphamide and unrelated donor (URD) HSCT. We searched the PubMed and Cochrane databases for pertinent studies indexed between 2008 and 2018. Twenty observational studies (with a total of 1783 haploidentical HSCT recipients and 6077 URD HSCT recipients) were included. Results for overall survival, graft-versus-host disease (GVHD), nonrelapse mortality (NRM), and relapse incidence were pooled. Measures of association used were hazard ratios and risk differences. The median age was 51 years for haploidentical transplant recipients and 52 years for URD transplant recipients. Peripheral blood stem cell (PBSC) grafts were more frequent in the URD transplant recipients (85%) than in the haploidentical transplant recipients (31%). Overall survival was not different between the 2 groups. NRM was lower for haploidentical transplantation. All forms of GVHD (acute grades II-IV and III-IV and moderate, severe, and extensive chronic) were lower with haploidentical donor HSCT. The risk of chronic GVHD was fairly proportional to the differential use of PBSC grafts across studies, however. All included studies were retrospective, representing the major limitation of this meta-analysis. In conclusion, haploidentical HSCT for hematologic malignancies achieved the same overall survival as URD HSCT, with a lower incidence of GVHD and NRM. The increased frequency of PBSC use in the unrelated donor group could partially explain the higher cGVHD rate. Haploidentical transplantation with post-transplantation cyclophosphamide should strongly be considered as the first option for adult patients with hematologic malignancies who do not have matched sibling donors in experienced centers. This systematic review has been registered at PROSPERO (65790).

Influence of Donor Type (Sibling versus Matched Unrelated Donor versus Haploidentical Donor) on Outcomes after Clofarabine-Based Reduced-Intensity Conditioning Allograft for Myeloid Malignancies

Clofarabine-based reduced-intensity conditioning (RIC) regimens are well-established schedules for allograft in patients with myeloid malignancies. A retrospective study was conducted including all adults allografted in our department with such a regimen and disease with the aim to assess whether or not the donor type (matched sibling [MSD], matched unrelated [MUD], or haploidentical [haplo]) impacted outcomes. Between October 2009 and February 2018, 118 patients met the inclusion criteria. Thirty-six, 55, and 27 patients received a graft from an MSD, MUD, or haplo donor, respectively. Peripheral blood stem cells (PBSCs) were the source of graft for all patients. The median age of the entire cohort was 62 years (range, 20 to 73), and the median follow-up was 31 months (range, 4.5 to 106). All patients engrafted except 1 haplo recipient. Neutrophils (>.5 × 10⁹/L) and platelets (50 × 10⁹/L) recoveries were significantly delayed in the haplo group (P = .0003 and P < .0001) compared with MSD and MUD. Acute grades II to IV or III to IV graft-versus-host disease (GVHD) incidences were similar between the 3 groups as well as the incidence of moderate or severe chronic GVHD. Also, similar 2-year overall survival (OS; 64.7% versus 73.9% versus 60.2%, P = .39), disease-free survival (DFS; 57.7% versus 70.9% versus and 53.6%, P = .1), and GVHD relapse-free survival (37.9% versus 54.3% versus 38.9%, P = .23) were observed between MSD versus MUD versus haplo groups. The same was true when considering only acute myeloid leukemia (AML) cases. In multivariate analysis the type of donor remained independent of outcomes in this series, whereas myelodysplastic syndrome (versus AML), high disease risk index, and older donor (≥50 years) were associated with lower OS and DFS. These data suggest that haplo donors are an acceptable alternative for patients receiving a clofarabine-based RIC PBSC allograft for myeloid malignancies who lack an MSD or a MUD.

Impact of conditioning intensity on outcomes of haploidentical stem cell transplantation for patients with acute myeloid leukemia 45 years of age and over

BACKGROUND

T cell-replete haploidentical stem cell transplantation (haplo-SCT) is a valid therapeutic option for adult patients with high-risk acute myeloid leukemia (AML) lacking an HLA-matched sibling or unrelated donor.

METHOD

We retrospectively analyzed the outcomes of 912 AML patients ≥45 years of age who had undergone haplo-SCT with either myeloablative conditioning (MAC; n = 373) or reduced intensity conditioning (RIC; n = 539) regimens.

RESULTS

The median follow-up was 31.1 and 25.7 months for MAC and RIC, respectively. The incidence of relapse and nonrelapse mortality (NRM) were 25.1% versus 28.7% and 31.0% versus 30.3% for MAC and RIC, respectively; 2-year leukemia-free survival (LFS) was 43.9% for MAC versus 41.0% for RIC. In multivariate analysis, the use of MAC versus RIC was not associated with a difference in the outcomes. Results were confirmed in the propensity score-weighted analysis. Disease status and performance status at transplantation were associated with outcomes. Notably, the use of posttransplantation cyclophosphamide was associated with reduced acute graft-versus-host disease (aGVHD) stage III-IV, and NRM and increased overall survival, LFS, and GVHD-free, relapse-free survival. The use of mobilized peripheral blood stem cells was associated with an increased risk of stage II-IV aGVHD.

CONCLUSION

No differences were found between MAC and RIC regimens for haplo-SCT in adults with AML who were ≥45 years of age. The type of GVHD prophylaxis, disease status, and performance status were the major predictors of transplantation outcome. These results may serve as the background for randomized study comparing RIC versus MAC for haplo-SCT in adults with AML.

Allogeneic Hematopoietic Stem Cell Transplantation for Older Patients With Acute Myeloid Leukemia

OPINION STATEMENT

Acute myelogenous leukemia (AML) in the elderly is complex and has a poor prognosis, often characterized by higher risk cytogenetic and molecular features compared to that in younger patients. Rates of transplant have been limited by concern related to non-relapse mortality, as older patients have historically been considered medically unfit for the transplantation process. Reduced-intensity conditioning (RIC) for hematopoietic stem cell transplantation (HSCT) has been shown to provide similar efficacy to myeloablative methods, with decreased non-relapse mortality in the elderly and improved efficacy over non-transplant approaches with cytotoxic chemotherapy alone. Targeted non-cytotoxic and modified cytotoxic agents have emerged to further improve transplant outcomes for older AML patients. Validated comorbidity indices are useful tools to assess an individual's fitness for undergoing HSCT rather than chronological age alone. We believe HSCT is the primary curative treatment approach for many older AML patients, taking into account risk and comorbidities, particularly given the tendency of leukemia in this population to harbor an unfavorable disease profile. We use RIC and advocate for the addition of targeted agents if applicable. With continuing data in support of transplant for older AML patients, we anticipate that transplant rates in this population will continue to rise.

Haploidentical versus matched donor stem cell transplantation for patients with hematological malignancies: a systemic review and meta-analysis

We compared the safety and efficacy of haploidentical stem cell transplantation (haplo-SCT) to matched donor SCT (matched-SCT) in treating hematological malignancies. The Medline, Cochrane, EMBASE, and Google Scholar databases were searched through 21 June 2017 using the search term "(hematological disease) AND matched AND (haploidentical OR haplo-identical OR haplo identical OR haplo transplantation OR haplo transplant OR haplo-SCT OR haplo-HSCT OR haplo-HCT)." Twenty-five studies enrolling 11,359 patients (haplo-SCT: 2677; matched-SCT: 8682) were included. The primary outcomes were acute and chronic graft-versus-host disease (GVHD), non-relapse mortality, and 1-year cumulative incidence of relapse. Haplo-SCT was associated with similar risks as matched-SCT for all primary endpoints. Subgroup analysis of patients who received a matched-SCT from a related donor revealed that patients who received haplo-SCT had a lower risk of acute GVHD. Among patients who received reduced-intensity conditioning (RIC), those who received haplo-SCT had a higher risk of acute grade II-IV GVHD and non-relapse mortality than did patients who received a matched-SCT from a related or unrelated donor. Haplo-SCT should continue to be considered as a safe and effective transplant option when a matched donor is unavailable, but it may not be suitable for patients who receive RIC.

Haploidentical Transplantation for Older Patients with Acute Myeloid Leukemia and Myelodysplastic Syndrome

Allogeneic stem cell transplantation with HLA-matched donors is increasingly used for older patients with acute myeloid leukemia (AML) and myelodysplastic syndrome (MDS). It remains unclear if haploidentical stem cell transplantation (haploSCT) is a suitable option for older patients with this disease. We analyzed 43 patients with AML/MDS (median age, 61 years) who underwent a haploSCT at our institution. All patients received a fludarabine-melphalan-based reduced-intensity conditioning regimen and post-transplant cyclophosphamide-based graft-versus-host disease (GVHD) prophylaxis. Except for 1 patient who had early death, the remaining 42 patients (98%) engrafted donor cells. The cumulative incidences of grades II to IV and III to IV acute GVHD at 6 months were 35% and 5%, respectively, and chronic GVHD at 2 years was 9%. After a median follow-up of 19 months, 2-year overall survival, progression-free survival (PFS), and relapse incidence were 42%, 42%, and 24%, respectively. Best PFS (74% at 2 years) was seen in patients with intermediate-/good-risk cytogenetics, in first or second remission (hazard ratio, .4; P = .05), and with a younger donor (≤40 years; hazard ratio, .2; P = .01). In conclusion, these data suggest that haploidentical transplantation is safe and effective for older AML/MDS patients. Disease status, cytogenetics, and younger donor age are predictors for improved survival in older patients receiving a haploidentical transplant.

Unmanipulated haploidentical in comparison with matched unrelated donor stem cell transplantation in patients 60 years and older with acute myeloid leukemia: a comparative study on behalf of the ALWP of the EBMT

Background

Acute myeloid leukemia (AML) is both more common and with more biologically aggressive phenotype in the elderly. Allogenic stem cell transplantation (allo-SCT) is the best treatment option in fit patients. Either HLA-matched unrelated donor (MUD) or haploidentical (Haplo) donor are possible alternative for patients in need.

Methods

We retrospectively compared non-T-cell-depleted Haplo (n = 250) to 10/10 MUD (n = 2589) in AML patients ≥ 60 years.

Results

Median follow-up was 23 months. Disease status at transplant differs significantly between the two groups (p < 10⁻⁴). Reduced intensity conditioning (RIC) was administrated to 73 and 77% of Haplo and MUD, respectively (p = 0.23). Stem cell source was the bone marrow (BM) in 52% of the Haplo and 6% of MUD (p < 10⁻⁴). Anti-thymocyte globulin (ATG) was most frequently used in MUD (p < 10⁻⁴) while post-Tx cyclophosphamide (PT-Cy) was given in 62% of Haplo. Engraftment was achieved in 90% of the Haplo vs 97% of MUD (p < 10⁻⁴). In multivariate analysis, no significant difference was found between Haplo and MUD for acute (a)graft versus host disease (GVHD) grade II–IV, relapse incidence (RI), non-relapse mortality (NRM), leukemia free survival (LFS), graft-versus-host-free-relapse free survival (GRFS), and overall survival (OS). Extensive chronic (c)GVHD was significantly higher for MUD as compared to Haplo (HR 2, p = 0.01, 95% CI 1.17–3.47). A propensity score analysis confirmed the higher risk of extensive cGVHD for MUD without differences for other outcomes.

Conclusions

Allo-SCT from both Haplo and MUD are valid option for AML patients ≥ 60 years of age with similar results. Transplantation from MUD was associated with higher extensive cGVHD. Our findings suggest that Haplo is a suitable and attractive graft source for patients≥ 60 with AML in need of allo-SCT.

Impact of Donor Type in Patients with AML Given Allogeneic Hematopoietic Cell Transplantation After Low-Dose TBI-Based Regimen

Purpose: We assessed the impact of donor type in acute myeloid leukemia (AML) patients transplanted with 2 Gy total body irradiation (TBI)-based nonmyeloablative conditioning regimen.Patients and Methods: Data from 1,715 adult patients, with AML in CR1 or CR2 were included in this retrospective survey.Results: Donors consisted either of HLA-matched sibling donors (MSD, n = 701), 10/10 HLA-matched unrelated donors (MUD, n = 611), HLA-haploidentical donors (haplo, n = 112) or single or double umbilical cord bloods (CBT, n = 291). Chronic graft-versus-host disease (GVHD) was less frequent in CBT (28%) and in haplo (30%) patients than in MSD (50%) and MUD (51%) recipients (P < 0.001). Two-year incidence of relapse was 32%, 30%, 34%, and 34% in MSD, MUD, CBT and haplo patients, respectively (P = 0.7). Two-year overall (OS) and GVHD-free relapse-free survival (GRFS) were 59% and 29% in MSD patients, 56% and 39% in CBT recipients, 53% and 23% in MUD recipients, and 43% and 37% in haplo patients, respectively. In multivariate analyses, MUD patients had lower GRFS than MSD patients beyond day 100 (HR 1.3, P = 0.001) while CBT was associated with a better GRFS than MSD beyond day 100 (HR 0.6, P = 0.002).Conclusions: In this large cohort of AML patients transplanted following low-dose TBI-based conditioning, the relapse incidence was not affected by donor type suggesting that the intensity of GVL effects might be comparable with these four transplant approaches. Furthermore, CBT was associated with better GRFS beyond day 100 than MSD while the opposite was observed for MUD. Clin Cancer Res; 24(12); 2794-803. ©2018 AACR.

Comparison of outcomes following transplantation with T-replete HLA-haploidentical donors using post-transplant cyclophosphamide to matched related and unrelated donors for patients with AML and MDS aged 60 years or older

Allografting from HLA-haploidentical donors (HID) is being increasingly utilized worldwide for patients lacking a conventional matched donor. However, its efficacy in older patients with AML and MDS is unclear. We analyzed 127 consecutive allografts for AML/MDS patients aged ≥ 60 years at our center to compare outcomes using HID to those of contemporaneous transplants using matched sibling (MRD) or matched unrelated (MUD) donors. Patient characteristics were similar except HID transplants were more likely in non-white patients and were more commonly performed with reduced intensity conditioning and a marrow graft. For MRD, MUD and HID transplants respectively, 2-year estimates of non-relapse mortality (17, 23, and 9%), relapse (32, 34, and 33%), overall survival (OS) (62, 55, and 67%) and disease-free survival (DFS) (51, 43, and 58%) were not significantly different. Maximum cumulative incidences of grade 2-4 acute GVHD were not different (27, 37, 39%), but incidences of NIH grade moderate to severe (39, 35, 15%, p = 0.028 MUD vs. HID, p = 0.026 MRD vs. HID) and severe chronic GVHD (9, 12, 0%, p = 0.030 MUD vs. HID, p = 0.009 MRD vs. HID) were significantly higher in MRD and MUD than in HID transplants. On multivariable analysis, donor type was not a significant determinant of OS, DFS, TRM, or relapse. However, male gender and high/very high Disease Risk Index (DRI) were associated with significantly higher rates of relapse (HR 1.94, p = 0.047 for male gender, HR 2.48, p = 0.004 for high/very high DRI) and lower OS (HR 1.94, p = 0.018 for male gender, HR 1.80, p = 0.025 for high/very high DRI). HIDs are an acceptable alternative to matched donors in older patients with AML and MDS.

Cost-effectiveness analysis of haploidentical vs matched unrelated allogeneic hematopoietic stem cells transplantation in patients older than 55 years

Due to limited donor availability, high comorbidities, and cost issues, allogeneic hematopoietic stem cell transplant is not universally accessible. The aim of this study was to conduct a cost-effectiveness analysis of haploidentical vs matched unrelated transplant. This retrospective study included patients with hematological malignancies older than 55 years who underwent haploidentical or matched unrelated transplant between 2011 and 2013 in Marseille. The incremental cost-effectiveness ratio has been calculated using the mean overall survival and the mean transplant costs. Costs were calculated using a micro-costing strategy from the hospital perspective and a time horizon at 2 years. Haploidentical transplant was considered an innovative procedure and matched unrelated transplant as the reference. Probabilistic and sensitivity analyses were performed on the incremental cost-effectiveness ratio. During inclusion, 29 patients underwent haploidentical transplant and 63 matched unrelated transplant. In haploidentical and matched unrelated transplant, the mean overall survival was 19.4 (1.6) months and 15.1 (1.2) months (p = 0.06), respectively, and the mean cost was 98,304 (40,872) € and 151,373 (65,742) € (p < 0.01), respectively. The incremental cost-effectiveness ratio was assessed to -148,485 (-1,265,550; -64,368) € per life year gained. Among older patients suffering from hematological malignancies, haploidentical transplant seemed in our analysis to be cost-effective compared with matched unrelated transplant.

Progressive multifocal leukoencephalopathy after T-cell replete HLA-haploidentical transplantation with post-transplantation cyclophosphamide graft-versus-host disease prophylaxis

A 52-year-old man suffered from progressive multifocal leukoencephalopathy (PML) after human leukocyte antigen (HLA)-haploidentical transplantation with post-transplantation cyclophosphamide (PTCY). Mirtazapine, mefloquine, and cytarabine failed to improve his symptoms, and he finally died 4.5 months after PML onset. This is the first case report of a patient with PML after HLA-haploidentical transplantation with PTCY. Although T-cell replete HLA-haploidentical transplantation with PTCY has enabled early immune reconstitution, PML should be considered if a patient's mental condition deteriorates.

Optimal donor for severe aplastic anemia patient requiring allogeneic hematopoietic stem cell transplantation: A large-sample study from China

HLA-haploidentical hematopoietic stem cell transplantation (HSCT) may be an option for severe aplastic anemia (SAA) patients. However, to date, no large-sample studies have been performed to determine which types of SAA patients are suitable for HLA-haploidentical HSCT. We retrospectively studied 189 consecutive patients with SAA who underwent HLA-identical or HLA-haploidentical HSCT at seven transplant centers in China. Propensity score matching (PSM) was applied in this study to reduce the influence of potential confounders. The 5-year overall survival (OS) rate was 72.0% in the HLA-haploidentical group and 76.5% in the HLA-identical group. The median time to achieve engraftment and the incidence of acute GVHD/chronic GVHD were not significantly different between the two groups. In the subgroup analysis, the outcome of patients older than 40 years in the HLA-haploidentical group was significantly poorer than that of patients younger than 40 years in the same group and that of patients older than 40 years in the HLA-identical group. Based on the above results, we suggest that HLA-haploidentical relative HSCT should be considered as a valid alternative option for patients younger than 40 years with SAA for whom no matched sibling donor is available.

Impact on early outcomes and immune reconstitution of high-dose post-transplant cyclophosphamide vs anti-thymocyte globulin after reduced intensity conditioning peripheral blood stem cell allogeneic transplantation

We have compared prospectively the outcome and immune reconstitution of patients receiving either post-transplant cyclophosphamide (PTCY) (n = 30) or anti-thymocyte globulin ATG (n = 15) as Graft-versus-host disease (GVHD) prophylaxis after reduced-intensity conditioning (RIC) allogeneic peripheral blood stem cell (PBSC) transplantation (allo-SCT). The outcome and immune reconstitution of patients receiving either of these two regimens were compared prospectively. This study allowed also to investigate the impact of PTCY between haplo-identical vs matched donors and of clofarabine as part of the RIC regimen. The γ/δ T-cells, α/β T-cells (CD8⁺ and CD4⁺), NK T-cells, NK cells, B-cells, Tregs and monocytes were analyzed by flow cytometry from a total of 583 samples. In the PTCY group significant delayed platelets recovery, higher CD3+ donor chimerism, higher HHV-6 and lower EBV reactivations were observed. Early survival advantage for CD4+ T-cells, Tregs and α/β T-cells was documented in the PTCY group while it was the case for α/β T-cells, NK cells and monocytes in the ATG group. Higher counts of NK and monocytes were observed at days +30 and/or day+60 in the ATG group. Both results were retained even in the case of mismatched donors. However, higher percentages of CD4+ T-cells, α/β T-cells and Tregs were observed with haplo-identical donors in the PTCY group. Finally, clofarabine was responsible for early survival advantage of NK T-cells in the PTCY group while it abrogated the early survival advantage of γ/δ T-cells in the ATG group. In conclusion, there are marked differences in the immunological effects of ATG vs PTCY as GVHD prophylaxis for RIC PBSC allo-SCT.

Comparable survival using a CMV-matched or a mismatched donor for CMV+ patients undergoing T-replete haplo-HSCT with PT-Cy for acute leukemia: a study of behalf of the infectious diseases and acute leukemia working parties of the EBMT

The role of donor CMV serostatus in the setting of non T-cell depleted haplo-HSCT with post-transplant cyclophosphamide (PT-Cy) has not been specifically addressed so far. Here we analyzed the impact of the donor CMV serological status on the outcome of 983 CMV seropositive (CMV+), acute leukemia patients receiving a first, non T-cell depleted haplo-HSCT registered in the EBMT database. The 1-year NRM was 21.3% (95% CI: 18.4-24.8) and 18.8% (95% CI: 13.8-25.5) in the CMV D+/R+ and D-/R+ pairs, respectively (p = 0.40). Similarly, 1-year OS was 55.1% (95% CI: 50.1-58.0) and 55.7% (95% CI: 48.0-62.8) in the same groups (p = 0.50). The other main outcomes were comparable. No difference in NRM nor OS was observed after stratification for the intensity of conditioning and multivariate anaysis confirmed the lack of significant association with NRM or OS. In conclusion, the choice of a CMV-seronegative donor did not impair early survival of CMV-seropositive patients with acute leukemia after a first, non T-cell depleted haploidentical HSCT and PT-Cy among this series of 983 consecutive patients. Future research may focus on the assessment of the hierarchy of all the donor variables.

Reduced-Intensity Allogeneic Transplant for Acute Myeloid Leukemia and Myelodysplastic Syndrome Using Combined CD34-Selected Haploidentical Graft and a Single Umbilical Cord Unit Compared with Matched Unrelated Donor Stem Cells in Older Adults

Haplo/cord transplantation combines an umbilical cord blood (UCB) graft with CD34-selected haploidentical cells and results in rapid hematopoietic recovery followed by durable UCB engraftment. We compared outcomes of transplants in older patients with acute myeloid leukemia (AML) or high-risk myelodysplastic syndromes (MDS) who received either HLA-matched unrelated donor (MUD) cells or haplo/cord grafts. Between 2007 and 2013, 109 adults ages 50 and older underwent similar reduced-intensity conditioning with fludarabine and melphalan and antibody-mediated T cell depletion for AML (n = 83) or high-risk MDS (n = 26) followed by either a MUD (n = 68) or haplo/cord (n = 41) graft. Patient characteristics were similar for each graft source except for more minority patients receiving a haplo/cord transplant (P = .01). One half of the AML patients were not in remission. Two-year progression-free survival (PFS), overall survival (OS), and graft-versus-host disease-free relapse-free survival were 38%, 48%, and 32.1% for MUD and 33%, 48%, and 33.8% for haplo/cord transplants (P = .62 for PFS; P = .97 for OS; P= .84), respectively. Acute grades II to IV and chronic graft-versus-host-disease rates did not differ at 19.5% and 4.9% in haplo/cord compared with 25% and 7.4% after MUD (P = .53 and P = .62, respectively). Multivariate analysis confirmed no significant differences in transplant outcomes by donor type. Haplo/cord reduced-intensity transplantation achieves similar outcomes relative to MUD in older AML and MDS patients, making this a promising option for those without matched donors.

Haploidentical hematopoietic cell transplantation for adult acute myeloid leukemia: a position statement from the Acute Leukemia Working Party of the European Society for Blood and Marrow Transplantation

Allogeneic blood or marrow hematopoietic cell transplantation continues to be the most potent anti-leukemic treatment for adult patients with standard, high-risk, or chemo-refractory acute myeloid leukemia. Until recently, this procedure was generally limited to those recipients who had an available matched-sibling donor or matched-unrelated donor. Technical advances in graft cell processing and manipulation, control of bidirectional T cell alloreactivity, graft-versus-host disease prophylaxis, and other supportive measures in haploidentical transplantation now enable nearly all patients with acute myeloid leukemia to benefit from the graft-versus-leukemia effect with substantial reduction in procedure-related mortality. Over recent years, haploidentical donors have been increasingly adopted as a valid donor source in allogeneic hematopoietic cell transplantation for acute myeloid leukemia in the absence of an HLA-matched donor. Among centers of the European Society for Blood and Marrow Transplantation, the use of haploidentical related donor transplantation has increased by 250% since 2010, and 291% since 2005. On behalf of the Acute Leukemia Working Party of the European Society for Blood and Marrow Transplantation, we summarize recent utilization trends in haploidentical transplantation for acute myeloid leukemia and describe the transformative changes in haploidentical hematopoietic cell transplantation techniques over the past decade, which have led to the current widespread use of this procedure. Furthermore, we review the efficacy of haploidentical hematopoietic cell transplantation for acute myeloid leukemia from available studies, including preliminary comparative studies, and bring attention to remaining unanswered questions and directions for future research. We conclude this report with our recommendations for the role of haploidentical hematopoietic cell transplantation in acute myeloid leukemia.

Similar outcomes after haploidentical transplantation with post-transplant cyclophosphamide versus HLA-matched transplantation: a meta-analysis of case-control studies

Background

Outcomes of haploidentical hematopoietic cell transplantation (haplo-HCT) with post-transplant cyclophosphamide (PT-Cy) have greatly improved. It remains unknown whether haplo-HCT with PT-Cy was associated with poor outcomes when compared with HLA-matched HCT. To address this issue, we performed a meta-analysis to compare outcomes of haplo-HCT with PT-Cy with those of HLA-matched HCT.

Methods

A systematic search for case-control studies were performed in PubMed, Embase and Cochrane Library databases. Using a random model, the risk ratios (RRs) and 95% confidence intervals (95% CI) were pooled for the final analysis.

Results

Nine case-control studies including 2258 patients (827 patients in the haplo-HCT with PT-Cy group, 748 controls from HLA-matched related donors (MRD), and 683 controls from HLA-matched unrelated donors (MUD)) met the inclusion criteria. No differences were found between haplo-HCT with PT-Cy and HLA-matched HCT with regard to acute graft-versus-host-disease (GVHD), non-relapse mortality, relapse, progression free survival and overall survival. However, haplo-HCT with PT-Cy was found to be associated with a lower incidence of moderate to severe chronic GVHD (Haplo vs MRD: RR=0.54; 95% CI=0.39-0.75; Haplo vs MUD: RR=0.70; 95% CI=0.56-0.88).

Conclusions

The results of this meta-analysis suggest that haplo-HCT with PT-Cy can achieve comparable outcomes with those of HLA-matched HCT. Haploidentical donors can be a feasible and valid alternative when conventional HLA-matched donors are unavailable.

Single-agent GvHD prophylaxis with tacrolimus after post-transplant high-dose cyclophosphamide is a valid option for haploidentical transplantation in adults with hematological malignancies

Eighty-one patients with high-risk hematological malignancies received unmanipulated haploidentical stem cell transplants (haploSCT) using the same protocol at four Spanish institutions. The conditioning regimen was thiotepa, busulfan and fludarabine; following bone marrow or peripheral blood infusion. GvHD prophylaxis with high-dose cyclophosphamide on days +3 and +4, and IV tacrolimus from day +5 was administered. 62% were in complete remission, 17% had received previous allogeneic SCT and 44% had a high-very high refined disease risk index. One patient had primary graft failure and three more died before +21. The median days to neutrophil and platelet recoveries were +18 and +23, respectively, and 93% achieved a full donor chimerism on day +30. At 1 year, cumulative incidences (CumInc) of non-relapse mortality and relapse were 27 and 19%. One-year overall survival and PFS were 61 and 51%. CumInc of grade II-IV and III-IV were 23 and 14%. At 30 months, CumInc of limited and extensive GvHD were 20 and 22%. In conclusion, patients with hematological malignancies who receive an unmanipulated haploSCT with post-transplant cyclophosphamide may benefit from less intense pharmacological prophylaxis for GvHD prophylaxis. Whether this approach potentiates the graft-versus-tumor effect and decreases relapses requires further investigation.

Minimal Residual Disease in Acute Myeloid Leukemia: Still a Work in Progress?

Minimal residual disease evaluation refers to a series of molecular and immunophenotypical techniques aimed at detecting submicroscopic disease after therapy. As such, its application in acute myeloid leukemia has greatly increased our ability to quantify treatment response, and to determine the chemosensitivity of the disease, as the final product of the drug schedule, dose intensity, biodistribution, and the pharmakogenetic profile of the patient. There is now consistent evidence for the prognostic power of minimal residual disease evaluation in acute myeloid leukemia, which is complementary to the baseline prognostic assessment of the disease. The focus for its use is therefore shifting to individualize treatment based on a deeper evaluation of chemosensitivity and residual tumor burden. In this review, we will summarize the results of the major clinical studies evaluating minimal residual disease in acute myeloid leukemia in adults in recent years and address the technical and practical issues still hampering the spread of these techniques outside controlled clinical trials. We will also briefly speculate on future developments and offer our point of view, and a word of caution, on the present use of minimal residual disease measurements in “real-life” practice. Still, as final standardization and diffusion of the methods are sorted out, we believe that minimal residual disease will soon become the new standard for evaluating response in the treatment of acute myeloid leukemia.

Outcomes of haploidentical transplant compared with matched donor allogeneic stem cell transplant

The risk of acute and chronic graft-versus-host disease (GVHD) with haploidentical transplant with post-transplant high-dose cyclophosphamide may be lower compared with matched unrelated donor transplant and largely similar to matched related donor transplant. The lower probability of GVHD with the haploidentical donor may result in a risk of nonrelapse mortality that is at least similar to or even lower than the matched donor. The incidence of relapse and survival are also largely similar to different donor types. Haploidentical transplant may be associated with slower engraftment. Given a lower risk of GVHD, haploidentical transplant has gained popularity. Additionally, the use of post-transplant high-dose cyclophosphamide has been extended to lower the risk of GVHD with matched donor and mismatched unrelated donor transplant.