T-cell-depleted haploidentical stem cell transplantation results improve with time in adults with acute leukemia: A study from the Acute Leukemia Working Party of the European Society of Blood and Marrow Transplantation (EBMT)

Cytokine Cocktail Promotes Alveolar Macrophage Reconstitution and Functional Maturation in a Murine Model of Haploidentical Bone Marrow Transplantation

Infectious pneumonia is one of the most common complications after bone marrow transplantation (BMT), which is considered to be associated with poor reconstitution and functional maturation of alveolar macrophages (AMs) post-transplantation. Here, we present evidence showing that lack of IL-13-secreting group 2 innate lymphoid cells (ILC2s) in the lungs may underlay poor AM reconstitution in a mouse model of haploidentical BMT (haplo-BMT). Recombinant murine IL-13 was able to potentiate monocyte-derived AM differentiation in vitro. When intranasally administered, a cocktail of granulocyte-macrophage colony-stimulating factor (GM-CSF), IL-13, and CCL2 not only promoted donor monocyte-derived AM reconstitution in haplo-BMT-recipient mice but also enhanced the innate immunity of the recipient animals against pulmonary bacterial infection. These results provide a useful clue for a clinical strategy to prevent pulmonary bacterial infection at the early stage of recipients post-BMT.

Haploidentical stem cell transplantation (HaploSCT) for patients with acute leukemia-an update on behalf of the ALWP of the EBMT

Allogeneic stem cell transplantations (alloSCT) from haploidentical (>2 HLA mismatch) donors (HaploSCT) are constantly increasing in Europe. From 2005 to 2015 numbers of HaploSCT increased by close to 300%. In parallel, there is a major shift from T deplete (CD34+ megadose) to T replete (non-T deplete) HaploSCT. Graft versus host disease (GVHD) prophylaxis also changed from CD34+ cell purifications to anti-thymocyte globulin (ATG) and lately to post-transplantation cyclophosphamide (PTCy). Novel conditioning regimens have been developed incorporating novel drugs and innovative approaches. Results are persistently improving and currently, registry-based and single-center studies showed no statistical significance difference in transplantation outcome between HaploSCT to alloSCT from unrelated donors and even from HLA-matched sibling donors, although the numbers of those studies are small and the lack of randomized studies available so far. HaploSCT have several advantages and such as the possibility to choose between different potential donors. Parameters to consider in the Haplo donor selection are age, gender, kinship, ABO blood group, CMV status, non-shared HLA Haplotypes and killer cell immunoglobulin-like receptor (KIR). Future goals are to further decrease transplant-related mortality currently mainly due to infection complications and reduce relapse rates especially in patients with high-risk acute leukemia.

Comparison of haplo-SCT and chemotherapy for young adults with standard-risk Ph-negative acute lymphoblastic leukemia in CR1

Abstract

Human leukocyte antigen (HLA) haploidentical stem cell transplantation (haplo-SCT) as a postremission treatment for standard risk Philadelphia chromosome-negative acute lymphoblastic leukemia (SR Ph-ALL) in the first complete remission (CR1) has not been defined. In this multicenter, phase 3 study (NCT02042690), of the 131 consecutive Ph-ALL young adult patients (YA, aged 18–39 years) without high-risk features who achieved CR1, 114 patients without HLA-matched donors received consolidation with an adult chemotherapy regimen (n = 55) or haplo-SCT (n = 59). In the landmark analysis, haplo-SCT resulted in a lower 2-year cumulative incidence of relapse (CIR, 12.8% vs 46.7%, P = 0.0017) and superior 2-year leukemia-free survival (LFS, 80.9% vs 51.1%, P = 0.0116) and 2-year overall survival (OS, 91.2% vs 75.7 [64.8–93.2] %, P = 0.0408) than chemotherapy. In the time-dependent multivariate analysis with propensity score adjustment, postremission treatment (haplo-SCT vs chemotherapy) was an independent risk factor for the CIR (HR 0.195, 95% CI 0.076–0.499, P = 0.001), LFS (HR 0.297, 95% CI 0.131–0.675, P = 0.003), and OS (HR 0.346, 95% CI 0.140–0.853, P = 0.011). In all subgroups, CIR was lower in haplo-SCT. Myeloablative haplo-SCT with ATG+G-CSF might be one of the preferred therapies for YA patients with standard-risk Ph-ALL.

Trial registration

ClinicalTrials.gov. Registered on 23 January 2014, https://clinicaltrials.gov/ct2/show/NCT02042690

The Evolution of T Cell Depleted Haploidentical Transplantation

Work on bone marrow transplantation from haploidentical donor has been proceeding for over 20 years all over the world and new transplant procedures have been developed. To control both graft rejection and graft vs. host disease, some centers have preferred to enhance the intensity of the conditioning regimens and the post-transplant immune suppression in the absence of graft manipulation; others have concentrated on manipulating the graft in the absence of any additional post-transplant immune suppressive agent. Due to the current high engraftment rates, the low incidence of graft-vs.-host disease and regimen related mortality, transplantation from haploidentical donors have been progressively offered even to elderly patients. Overall, survivals compare favorably with reports on transplants from unrelated donors. Further improvements will come with successful implementation of strategies to enhance post-transplant immune reconstitution and to prevent leukemia relapse.

Expanding Therapeutic Opportunities for Hematopoietic Stem Cell Transplantation: T Cell Depletion as a Model for the Targeted Allograft

Allogeneic hematopoietic cell transplantation is a fundamental part of the treatment of hematologic malignancies and marrow failure syndromes, but complications including graft-versus-host disease, prolonged immune deficiency and infection, and organ toxicities, as well as relapse, remain obstacles to improved overall survival. As the cellular characteristics of the allograft can exert significant impact on outcomes, the development of more strategically designed grafts represents a rich area for therapeutic intervention. We describe the use of ex vivo T cell–depleted grafts as a model for the targeted graft and review evolving knowledge and approaches for further refinement of allografts to improve patient outcomes.

Myeloablative Haploidentical Transplantation Is Superior to Chemotherapy for Patients with Intermediate-risk Acute Myelogenous Leukemia in First Complete Remission

PURPOSE

Although myeloablative HLA haploidentical hematopoietic stem cell transplantation (haplo-HSCT) following pretransplant anti-thymocyte globulin (ATG) and granulocyte colony-stimulating factor (G-CSF) stimulated grafts (ATG+G-CSF) has been confirmed as an alternative to HSCT from HLA-matched sibling donors (MSD), the effect of haplo-HSCT on postremission treatment of patients with acute myeloid leukemia (AML) with intermediate risk (int-risk AML) who achieved first complete remission (CR1) has not been defined.

PATIENTS AND METHODS

In this prospective trial, among 443 consecutive patients ages 16-60 years with newly diagnosed de novo AML with int-risk cytogenetics, 147 patients with molecular int-risk AML who achieved CR1 within two courses of induction and remained in CR1 at 4 months postremission either received chemotherapy (n = 69) or underwent haplo-HSCT (n = 78).

RESULTS

The 3-year leukemia-free survival (LFS) and overall survival (OS) were significantly higher in the haplo-HSCT group than in the chemotherapy group (74.3% vs. 47.3%; P = 0.0004 and 80.8% vs. 53.5%; P = 0.0001, respectively). In the multivariate analysis with propensity score adjustment, postremission treatment (haplo-HSCT vs. chemotherapy) was an independent risk factor affecting the LFS [HR 0.360; 95% confidence interval (CI), 0.163-0.793; P = 0.011], OS (HR 0.361; 95% CI, 0.156-0.832; P = 0.017), and cumulative incidence of relapse (HR 0.161; 95% CI, 0.057-0.459; P = 0.001) either in entire cohort or stratified by minimal residual disease after the second consolidation.

CONCLUSIONS

Myeloablative haplo-HSCT with ATG+G-CSF is superior to chemotherapy as a postremission treatment in patients with int-risk AML during CR1. Haplo-HSCT might be a first-line postremission therapy for int-risk AML in the absence of HLA-MSDs. Haplo-HSCT might be superior to chemotherapy as a first-line postremission treatment of intermediate-risk AML in CR1.

Second allogeneic hematopoietic cell transplantation enables long-term disease-free survival in relapsed acute leukemia

Allogeneic hematopoietic cell transplantation (HCT) is the treatment of choice for high-risk myeloid and lymphoid leukemias. Relapse after allogeneic HCT is associated with a dismal prognosis and further therapeutic options are limited. One potential curative approach is a second allogeneic HCT. However, there is no consensus about optimal transplant modalities, suitable patients, and entities. We performed a retrospective analysis of our institutional database to evaluate risk factors that influence survival after a second allogeneic HCT for the treatment of relapsed acute myeloid leukemia (AML) and acute lymphoblastic leukemia (ALL). We identified 40 patients (AML, n = 29; ALL, n = 11) that received a second allogeneic HCT at our institution. At time of second HCT, 48% of patients were in complete remission (CR). Current overall survival (OS) was 14/40 patients with a median follow-up of 64 months (range 4-140) of patients alive resulting in a Kaplan-Meier estimated 2-year event-free survival (EFS) and OS of 32%, respectively. Cumulative incidence of non-relapse mortality (NRM) and relapse at 2 years was 31 and 37%, respectively. We identified several independent risk factors influencing OS: > 6 months from first to second transplant (p = 0.02), complete remission prior to transplant (p = 0.003), and the subsequent occurrence of chronic graft-versus-host disease (p = 0.003) were associated with a significantly improved OS. In conclusion, our data suggest that a second allogeneic HCT is a curative treatment option for relapsed acute leukemias in selected patients.