Second hematopoietic SCT for leukemia relapsing after myeloablative T cell-depleted transplants does not prolong survival

Outcome of donor-derived TAA-T cell therapy in patients with high-risk or relapsed acute leukemia post allogeneic BMT

Patients with hematologic malignancies relapsing after allogeneic blood or marrow transplantation (BMT) have limited response to conventional salvage therapies, with an expected 1-year overall survival (OS) of <20%. We evaluated the safety and clinical outcomes following administration of a novel T-cell therapeutic targeting 3 tumor-associated antigens (TAA-T) in patients with acute leukemia who relapsed or were at high risk of relapse after allogeneic BMT. Lymphocytes obtained from the BMT donor were manufactured to target TAAs WT1, PRAME, and survivin, which are over-expressed and immunogenic in most hematologic malignancies. Patients received TAA-T infusions at doses of 0.5 to 4 × 107/m2. Twenty-three BMT recipients with relapsed/refractory (n = 11) and/or high-risk (n = 12) acute myeloid leukemia (n = 20) and acute lymphoblastic leukemia (n = 3) were infused posttransplant. No patient developed cytokine-release syndrome or neurotoxicity, and only 1 patient developed grade 3 graft-versus-host disease. Of the patients who relapsed post-BMT and received bridging therapy, the majority (n = 9/11) achieved complete hematologic remission before receiving TAA-T. Relapsed patients exhibited a 1-year OS of 36% and 1-year leukemia-free survival of 27.3% post-TAA-T. The poorest prognosis patients (relapsed <6 months after transplant) exhibited a 1-year OS of 42.8% postrelapse (n = 7). Median survival was not reached for high-risk patients who received preemptive TAA-T posttransplant (n = 12). Although as a phase 1 study, concomitant antileukemic therapy was allowed, TAA-T were safe and well tolerated, and sustained remissions in high-risk and relapsed patients were observed. Moreover, adoptively transferred TAA-T detected by T-cell receptor V-β sequencing persisted up to at least 1 year postinfusion. This trial was registered at clinicaltrials.gov as #NCT02203903.

Second unmanipulated allogeneic transplantation could be used as a salvage option for patients with relapsed acute leukemia post-chemotherapy plus modified donor lymphocyte infusion

Relapse is the main problem after allogeneic hematopoietic stem cell transplantation (allo-HSCT). The outcome of a second allo-HSCT (HSCT2) for relapse post-HSCT has shown promising results in some previous studies. However, little is known about the efficacy of HSCT2 in patients with relapsed/refractory acute leukemia (AL) post-chemotherapy plus modified donor lymphocyte infusion (post-Chemo + m-DLI) after the first allo-HSCT (HSCT1). Therefore, we retrospectively analyzed the efficacy of HSCT2 in 28 patients with relapsed/refractory AL post-Chemo + m-DLI in our center. With a median follow-up of 918 (457-1732) days, 26 patients (92.9%) achieved complete remission, and 2 patients exhibited persistent disease. The probabilities of overall survival (OS) and disease-free survival (DFS) 1 year after HSCT2 were 25.0% and 21.4%, respectively. The cumulative incidences of nonrelapse mortality on day 100 and at 1 year post-HSCT2 were 7.1% ± 4.9% and 25.0% ± 8.4%. The cumulative incidences of relapse were 50.0% ± 9.8% and 53.5% ± 9.9% at 1 and 2 years post-HSCT2, respectively. Risk stratification prior to HSCT1 and percentage of blasts before HSCT2 were independent risk factors for OS post-HSCT2, and relapse within 6 months post-HSCT1 was an independent risk factor for DFS and relapse post-HSCT2. Our findings suggest that HSCT2 could be a salvage option for patients with relapsed AL post-Chemo + m-DLI.

Long-Term Molecular Remission Achieved by Antibody Anti-CD22 and Ponatinib in a Patient Affected by Ph'+ Acute Lymphoblastic Leukemia Relapsed after Second Allogeneic Hematopoietic Stem Cell Transplantation: A Case Report

Ph'+ acute lymphoblastic leukemia (Ph'+-ALL) is an oncohematologic disorder for which allogeneic bone marrow transplantation still offers the only chance of cure. However, relapse is the main reason for treatment failure, also after hematopoietic stem cell transplantation (HSCT). New drugs, such as third generation tyrosine kinase inhibitors (TKIs) and monoclonal antibodies, have expanded the therapeutic landscape, especially in patients who relapsed before HSCT. Very few reports, up to now, have described the use of both classes of these new agents in combination with donor lymphocyte infusions (DLI) in the setting of patients who relapsed after HSCT. We report on a young patient affected by Ph'+-ALL, who relapsed after the second HSCT and who reached molecular remission and long-term disease control by treatment with the anti-CD22 monoclonal antibody inotuzumab ozogamicin, DLI, and the 3rd generation TKI ponatinib.

Strategies to enhance the graft versus tumour effect after allogeneic haematopoietic stem cell transplantation

Relapse of haematological malignancies after allogeneic haematopoietic stem cell transplant is a major cause of mortality. The immunological mechanisms that may lead to disease relapse may include immunological immaturity prior to reconstitution of the allogeneic immune system, tumour antigen downregulation or promotion of T-cell exhaustion by interactions with the tumour microenvironment. Current therapeutic strategies for post-transplant relapse are limited in their efficacy and alternative approaches are required. In this review, we discuss the mechanisms of T and NK-cell immune evasion that facilitate relapse of haematological malignancies after allogeneic stem cell transplantation, and explore emerging strategies to augment the allogeneic immune system in order to construct a more potent graft versus tumour response.

Second Hematopoietic Stem Cell Transplantation for Post-Transplantation Relapsed Acute Leukemia in Children: A Retrospective EBMT-PDWP Study

Outcome data were collected from the European Society for Blood and Marrow Transplantation registry on 373 children from 120 centers with relapsed leukemia (214 with acute lymphoblastic leukemia [ALL] and 159 with acute myelogenous leukemia [AML]) who underwent second allogeneic hematopoietic stem cell transplantation (HSCT) between 2004 and 2013. Overall survival (OS) was 38% at 2 years and 29% at 5 years, and leukemia-free survival (LFS) was 30% at 2 years and 25% at 5 years. Median follow-up after second HSCT was 36.4 months in the ALL group and 50.2 months in the AML group. In the ALL group, OS was 43% at 2 years and 33% at 5 years, and LFS was 34% at 2 years and 31% at 5 years. In the AML group, OS was 32% at 2 years and 24% at 5 years, and LFS was 24% at 2 years and 17% at 5 years. The 2-year nonrelapse mortality (NRM) rate was 22% in the ALL group and 18% in the AML group. Favorable prognostic factors (P < .05) for OS and LFS included >12 months between transplantations and chronic graft-versus-host disease after the first HSCT (in both groups), complete response before the second HSCT (ALL group only), and age >12 years (AML group only). Findings were more consistent over time in the ALL group, with no significant differences between 2-year and 5-year rates of relapse, NRM, and LFS. Children with relapsed acute leukemias have a substantial likelihood of long-term survival following second HSCT. Given the many novel targeted and immunomodulation therapies currently under development, it is important to identify specific patient subpopulations that may benefit from a second HSCT compared with those better suited to new approaches.

CD34-Selected Hematopoietic Stem Cell Transplants Conditioned with Myeloablative Regimens and Antithymocyte Globulin for Advanced Myelodysplastic Syndrome: Limited Graft-versus-Host Disease without Increased Relapse

Allogeneic hematopoietic stem cell transplantation (allo-HSCT) is the only curative therapy for patients with myelodysplastic syndrome (MDS). Donor T cells are critical for the graft-versus-tumor effect but carry the risk of graft-versus-host disease (GVHD). CD34 selection with immunomagnetic beads has been an effective method of depleting alloreactive donor T cells from the peripheral blood graft and has been shown to result in significant reduction in acute and chronic GVHD. We analyzed the outcomes of 102 adults (median age, 57.6 years) with advanced MDS who received a CD34-selected allo-HSCT between January 1997 and April 2012 at Memorial Sloan Kettering Cancer Center. The cumulative incidences of grades II to IV acute GVHD were 9.8% at day 100 (95% confidence interval [CI], 5.0% to 16.5%) and 15.7% at day 180 (95% CI, 9.4% to 23.4%). The cumulative incidence of chronic GVHD at 1 year was 3.9% (95% CI, 1.3% to 9.0%). The cumulative incidences of relapse were 11.8% at 1 year (95% CI, 6.4% to 18.9%) and 15.7% at 2 years (95% CI, 9.4% to 23.4%). Forty-eight patients were alive with a median follow-up of 71.7 months. Rates of overall survival (OS) were 56.9% at 2 years (95% CI, 48% to 67.3%) and 49.3% at 5 years (95% CI, 40.4% to 60.2%). Rates of relapse-free survival (RFS) were 52.0% at 2 years (95% CI, 41.9% to 61.1%) and 47.6% at 5 years (95% CI, 37.5% to 56.9%). The cumulative incidences of nonrelapse mortality were 7.8% at day 100 (95% CI, 3.7% to 14.1%), 22.5% at 1 year (95% CI, 15.0% to 31.1%), and 33.4% at 5 years (95% CI, 24.2% to 42.6%) post-transplant. The incidence of chronic GVHD/RFS overlapped with RFS. These findings demonstrate that ex vivo T cell-depleted allo-HSCT by CD34 selection offers long-term OS and RFS with low incidences of acute and chronic GVHD and without an increased risk of relapse.

Outcomes of Cord Blood Transplantation as Salvage Therapy after Graft Failure or Relapse after Prior Allogeneic Transplantation

For patients with disease relapse or graft failure after allogeneic hematopoietic cell transplantation (HCT), there are few treatment options and survival rates are exceedingly low. Because of the unacceptably high risk of transplantation-related mortality, second allogeneic HCTs are often not considered. Herein, we report the outcomes of 23 patients (median age, 33 years) undergoing a second allogeneic transplantation with unrelated cord blood donor grafts between 2006 and 2013. Indications for second HCT were relapse (n = 19), graft failure (n = 3), and donor-derived myelodysplastic syndrome (n = 1). Ten patients received reduced-intensity conditioning and 13 patients received either myeloablative (MAC) or middle-intensity (MIDI) conditioning. Twenty patients received a double cord blood transplantation. All patients engrafted at a median of 22 days (range, day 6 to 49). Death before day 100 occurred in 5 patients. Overall disease-free survival (DFS), treatment-related mortality, and relapse at 2 years were 31%, 33%, and 35%, respectively. Two-year DFS in the 13 patients receiving MAC or MIDI conditioning was slightly higher at 46%. Our results demonstrate that second allogeneic HCT using cord blood as the graft source should be considered in patients who have relapsed or experience graft failure after an allogeneic HCT.

Management of relapses after hematopoietic cell transplantation in T-cell non-Hodgkin lymphomas

T-cell non-Hodgkin lymphomas (NHLs) are a heterogeneous group of malignancies that represent 10%-15% of all NHLs. The prognosis of relapsed T-cell NHL is poor, especially for those relapsing after an autologous (auto-) or allogeneic (allo-) hematopoietic cell transplantation (HCT). Disease relapse post auto-HCT is best managed on a clinical trial. In the absence of an investigational protocol, the choice of salvage therapies should take into account patient performance status, eligibility for an allo-HCT, and surface CD30 expression. CD30-directed therapies or aggressive salvage regimens can be used as a bridge to allo-HCT in medically fit patients. In the elderly or more infirm patients, single-agent therapies could be offered, aiming at palliation. Similarly, relapse after an allo-HCT is not uncommon and is a real challenge. Reduction in ongoing immune suppression or donor lymphocyte infusion are often considered in this setting to augment graft-versus-lymphoma (GVL) effects and can occasionally provide durable disease control. Clinical trials designed to investigate novel therapeutic agents with immunomodulatory properties to augment GVL effects (eg, histone deacetylase [HDAC] inhibitors, proteasome inhibitor, lenalidomide) or targeted therapies (eg, aurora A kinase inhibitors, anaplastic lymphoma kinase [ALK] inhibitors) are sorely needed to improve the dismal outcomes of T-cell NHL relapsing after an allo-HCT.