The use of venetoclax-based salvage therapy for post-hematopoietic cell transplantation relapse of acute myeloid leukemia.

For patients with high risk myeloid disease, allogeneic hematopoietic cell transplantation (HCT) is the only potentially curative therapy. Unfortunately, many of these patients relapse after HCT and have a limited survival. The recent approval of venetoclax, an orally bioavailable BCL-2 inhibitor, resulted in significant responses in treatment naïve acute myeloid leukemia (AML), and off-label use in the relapsed/refractory setting is increasing. We report the outcomes of 21 patients who underwent allogeneic HCT for myeloid disease, relapsed with AML, and were treated with venetoclax. Several patients had poor risk features including antecedent hematologic malignancy (6/21), complex karyotype (6/21), and TP53 mutations (5/21). The median age was 64.5 years and time from HCT to relapse was 5.7 months (range: 0.9 to 44.9 months). Of the 19 patients who were assessed for response, there were meaningful treatment responses seen in eight patients: five CR, three CRi, zero PR, for an ORR of 42.1%. Treatment effect was seen in six additional patients, including four in the morphologic leukemia-free state. Nine patients maintained their response for ≥3 months and eight were receiving therapy at data cut. Post-HCT AML relapse has an exceedingly poor outcome, and venetoclax-based therapy is a potent therapy option that should be studied prospectively in this setting.

Optimizing Antithymocyte Globulin Dosing for Unrelated Donor Allogeneic Hematopoietic Cell Transplantation Based on Recipient Absolute Lymphocyte Count.

Antithymocyte globulin (ATG) is used as prophylaxis against graft-versus-host disease (GVHD). Current dosing regimens for ATG are empiric and weight-based, and do not account for patient-specific factors. Furthermore, the target of ATG, recipient T cells post-cytotoxic chemotherapy, is not a function of recipient weight. We hypothesized the recipient peripheral blood absolute lymphocyte count (ALC) on the day of ATG administration would interact with the dose of ATG administered to predict transplantation outcomes. We retrospectively analyzed 135 patients who received ATG for GVHD prophylaxis for unrelated allogeneic hematopoietic cell transplantation at 3 different doses: 10 mg/kg, 7.5 mg/kg, and 5 mg/kg. There was no difference in 2-year overall survival (OS) among ATG dosing groups; however, deaths from infectious complications were significantly higher with higher doses of ATG (3.7% versus 19% versus 26.7%; P = .02). Severity of chronic GVHD was lower with higher doses of ATG (28% versus 24% versus 4%; P = .03). In multivariate analysis, the median peripheral blood ALC on day of ATG administration and the total amount of ATG interacted to predict OS (hazard ratio, .09; P = .03). For low recipient ALC (10th percentile, or .56 × 102/µL), a higher total ATG dose was associated with a greater risk of death, whereas for high recipient ALC (90th percentile, or 24.96 × 102/µL), a higher ATG dose was associated with a lower risk of death. Our findings suggest that the interaction between ATG and its target, the recipient lymphocyte, could represent a new paradigm for ATG dosing.

Transplant Outcomes for Secondary Acute Myeloid Leukemia: Acute Leukemia Working Party of the European Society for Blood and Bone Marrow Transplantation Study.

Secondary acute myeloid leukemia (sAML) has been associated with inferior outcomes compared with de novo AML. Little is known about patient risk factors and outcomes in sAML after allogeneic hematopoietic stem cell transplantation (HCT); thus, this large systemic analysis of the European Society for Blood and Bone Marrow Transplantation registry was performed. This study included 4997 patients with sAML who received HCT from 2000 to 2016. In univariate analysis the 2-year cumulative incidence of chronic graft-versus-host disease (GVHD), relapse, and nonrelapse mortality (NRM) were 33.5% (95% confidence interval [CI], 32% to 34.9%), 33.7% (95% CI, 32.3% to 35.1%), and 27.5% (95% CI, 26.1% to 28.7%), respectively. Overall survival (OS), leukemia-free survival (LFS), and GVHD-free, relapse-free survival (GRFS) at 2 years were 44.5% (95% CI, 43% to 46%), 38.8% (95% CI, 37.4% to 40.3%), and 27.2% (95% CI, 25.9% to 28.6%), respectively. In multivariate analysis, patients receiving myeloablative regimens had decreased relapse (hazard ratio, .859; 95% CI, .761 to .97; P = .01), higher NRM (hazard ratio, 1.175; 95% CI, 1.03 to 1.341; P = .02), and no differences in OS, LFS, and GRFS compared with patients receiving reduced-intensity conditioning regimens. Active disease, adverse cytogenetics, older age, Karnofsky performance status (≤80%), ex vivo T cell depletion, other malignant hematologic diseases, and patient cytomegalovirus seropositivity were associated with inferior OS and LFS. These variables should be considered in patients with sAML in need of HCT, and further study regarding the impact of conditioning regimens on relapse is needed.

Metabolic Complications Precede Alloreactivity and Are Characterized by Changes in Suppression of Tumorigenicity 2 Signaling.

New-onset post-transplantation diabetes mellitus (PTDM) occurs commonly after allogeneic hematopoietic cell transplantation (HCT) and is associated with inferior survival. We hypothesize that PTDM and nonrelapse mortality (NRM) are related to IL-33/suppression of tumorigenicity 2 (ST2) signaling and that soluble ST2 (sST2) levels will predict PTDM diagnosis. sST2 was measured at engraftment and day +30 in 36 euglycemic HCT recipients followed prospectively for PTDM (cohort 1). Results were confirmed in a validation cohort of 26 patients without pre-existing diabetes analyzed retrospectively for PTDM (cohort 2). Twelve patients with established diabetes before HCT were analyzed in cohort 3. When compared with recipients without PTDM, patients developing PTDM (n = 24) from cohort 1 had elevated sST2 levels at engraftment (P = .02) and at day +30 (P < .01). Cohort 2 confirmed this finding at engraftment (P = .01). Cohort 3 patients with pretransplantation diabetes had higher sST2 at engraftment than patients maintaining euglycemia after HCT from cohort 2 (P = .03). Multivariate analysis of cohorts 1 and 2 showed high engraftment sST2 predicted increased PTDM and NRM risk, independent of conditioning and grades 3 to 4 acute graft-versus-host-disease. sST2 was elevated in PTDM, indicating a relationship between glucose homeostasis and the IL-33/ST2 axis after transplantation. Correction of metabolic complications may decrease sST2 and improve NRM.

Reduced-Intensity Conditioning with Fludarabine, Cyclophosphamide, and Rituximab Is Associated with Improved Outcomes Compared with Fludarabine and Busulfan after Allogeneic Stem Cell Transplantation for B Cell Malignancies.

Reduced-intensity conditioning (RIC) has been used increasingly for allogeneic hematopoietic cell transplantation to minimize transplant-related mortality while maintaining the graft-versus-tumor effect. In B cell lymphoid malignancies, reduced-intensity regimens containing rituximab, an antiCD20 antibody, have been associated with favorable survival; however, the long-term outcomes of rituximab-containing versus nonrituximab-containing regimens for allogeneic hematopoietic cell transplantation in B cell lymphoid malignancies remain to be determined. We retrospectively analyzed 94 patients who received an allogeneic transplant for a B cell lymphoid malignancy. Of these, 33 received RIC with fludarabine, cyclophosphamide, and rituximab (FCR) and graft-versus-host disease (GVHD) prophylaxis with a calcineurin inhibitor and mini-methotrexate, and 61 received RIC with fludarabine and busulfan (FluBu) and GVHD prophylaxis with a calcineurin inhibitor and mycophenolate mofetil. The 2-year overall survival was superior in patients who received FCR versus FluBu (72.7% versus 54.1%, P = .031), and in multivariable analysis adjusted for Disease Risk Index and donor type, only the conditioning regimen (FluBu versus FCR: HR, 2.06; 95% CI, 1.04 to 4.08; P = .037) and Disease Risk Index (low versus intermediate/high: HR, .38; 95% CI, .17 to .86; P = .02) were independent predictors of overall survival. The 2-year cumulative incidence of chronic GVHD was lower in patients who received FCR versus FluBu (24.2% versus 51.7%, P = .01). There was no difference in rate of relapse/progression or acute GVHD. Our results demonstrate that the use of RIC with FCR and GVHD prophylaxis with a calcineurin inhibitor and mini-methotrexate is associated with decreased chronic GVHD and improved overall survival.

Does FLT3 mutation impact survival after hematopoietic stem cell transplantation for acute myeloid leukemia? A Center for International Blood and Marrow Transplant Research (CIBMTR) analysis.

BACKGROUND: Patients with FMS like tyrosine kinase 3 (FLT3)-mutated acute myeloid leukemia (AML) have a poor prognosis and are referred for early allogeneic hematopoietic stem cell transplantation (HCT). METHODS: Data from the Center for International Blood and Marrow Transplant Research (CIBMTR) were used to evaluate 511 adult patients with de novo AML who underwent HCT during 2008 through 2011 to determine whether FLT3 mutations had an impact on HCT outcomes. RESULTS: In total, 158 patients (31%) had FLT3 mutations. Univariate and multivariate analyses revealed an increased risk of relapse at 3 years in the FLT3 mutated group compared with the wild-type (WT) group (38% [95% confidence interval (CI), 30%-45%] vs 28% [95% CI, 24%-33%]; P = .04; relative risk, 1.60 [95% CI, 1.15-2.22]; P = .0048). However, FLT3 mutation status was not significantly associated with nonrelapse mortality, leukemia-free survival, or overall survival. Although more patients in the FLT3 mutated group died from relapsed primary disease compared with those in the WT group (60% vs 46%), the 3-year overall survival rate was comparable for the 2 groups (mutated group: 49%; 95% CI, 40%-57%; WT group: 55%, 95% CI, 50%-60%; P = .20). CONCLUSIONS: The current data indicate that FLT3 mutation status did not adversely impact overall survival after HCT, and about 50% of patients with this mutation who underwent HCT were long-term survivors. Cancer 2016;122:3005-3014. © 2016 American Cancer Society.

Hematopoietic Stem Cell Transplantation for Multiple Myeloma: Guidelines from the American Society for Blood and Marrow Transplantation.

Therapeutic strategies for multiple myeloma (MM) have changed dramatically over the past decade. Thus, the role of hematopoietic stem cell transplantation (HCT) must be considered in the context of this evolution. In this evidence-based review, we have critically analyzed the data from the most recent clinical trials to better understand how to incorporate HCT and when HCT is indicated. We have provided our recommendations based on strength of evidence with the knowledge that ongoing clinical trials make this a dynamic field. Within this document, we discuss the decision to proceed with autologous HCT, factors to consider before proceeding to HCT, the role of tandem autologous HCT, post-HCT maintenance therapy, and the role of allogeneic HCT for patients with MM.

Reduced intensity conditioning allogeneic hematopoietic cell transplantation for adult acute myeloid leukemia in complete remission - a review from the Acute Leukemia Working Party of the EBMT.

Acute myeloid leukemia is the most common indication for an allogeneic hematopoietic cell transplant. The introduction of reduced intensity conditioning has expanded the recipient pool for transplantation, which has importantly made transplant an option for the more commonly affected older age groups. Reduced intensity conditioning allogeneic transplantation is currently the standard of care for patients with intermediate or high-risk acute myeloid leukemia and is now most often employed in older patients and those with medical comorbidities. Despite being curative for a significant proportion of patients, post-transplant relapse remains a challenge in the reduced intensity conditioning setting. Herein we discuss the studies that demonstrate the feasibility of reduced intensity conditioning allogeneic transplants, compare the outcomes of reduced intensity conditioning versus chemotherapy and conventional myeloablative conditioning regimens, describe the optimal donor and stem cell source, and consider the impact of post-remission consolidation, comorbidities, center experience, and more intensive (reduced toxicity conditioning) regimens on outcomes. Additionally, we discuss the need for further prospective studies to optimize transplant outcomes.

Cytotoxic T-lymphocyte antigen-4 single nucleotide polymorphisms are not associated with outcomes after unrelated donor transplantation: a center for international blood and marrow transplant research analysis.

Cytotoxic T-lymphocyte antigen-4 (CTLA-4) plays an essential role in T cell homeostasis by restraining immune responses. AG and GG genotypes of donor CTLA-4 SNP rs4553808 in patients after unrelated donor hematopoietic stem cell transplantations (HSCT) have been shown to be an independent predictor of inferior relapse-free survival (RFS) and overall survival (OS) compared with those with the AA genotype, in single-center studies. We tested the hypothesis that SNP rs4553808 is associated with RFS, OS, nonrelapse mortality (NRM) and the cumulative incidence of acute graft-versus-host disease (GVHD) and chronic GVHD in adults with acute myeloid leukemia and advanced myelodysplastic syndrome undergoing a first 8/8 or 7/8 HLA-matched unrelated donor HSCT. Multivariable analysis adjusting for relevant donor and recipient characteristics showed no significant association between SNP rs4553808 and OS, RFS, NRM, and incidence of acute and chronic GVHD. An exploratory analysis of other CTLA-4 SNPs, as well as studying the interaction with antithymocyte globulin, also demonstrated no significant associations. Our results indicate that CTLA-4 SNPs are not associated with HSCT outcomes.

Efficacy and safety of outpatient fludarabine, cyclophosphamide, and rituximab based allogeneic hematopoietic cell transplantation in adults with severe aplastic anemia.

The age effect in severe aplastic anemia (SAA) following allogeneic hematopoietic cell transplantation (HCT) favors the use of reduced intensity conditioning (RIC) regimens in older adults. We implemented a non-myeloablative regimen consisting of fludarabine, cyclophosphamide, and rituximab (FCR) to improve HCT outcomes in SAA. Patients who underwent first HCT for SAA utilizing an FCR regimen between January 2016 and May 2022 were included. Outcomes analyzed included time to engraftment, incidence of graft failure, GVHD, viral reactivation, disease recurrence, and GVHD-free, relapse-free survival (GRFS). Among 24 patients included, median age was 43.5 years (22-62) and a variety of donor types and stem cell sources were represented. At median follow-up of 26.9 months (2.4-72.7), no cases of grade III-IV acute (aGVHD) or severe chronic GVHD (cGVHD) were recorded. Viral reactivation was minimal, and there were no cases of graft failure or PTLD, with 100% disease-free and overall survival at last follow up. The estimate of 1-year GRFS was 86.3% (95% CI: 72.8-100%), with moderate cGVHD accounting for all events. The FCR regimen in SAA was well tolerated, even in older adults, with 100% disease-free survival with low GVHD and infection rates. These encouraging findings should be validated in larger prospective trials.

New allergies after cord blood transplantation.

BACKGROUND AIMS: Umbilical cord blood transplantation (CBT) is an effective treatment for benign and malignant diseases. Late effects of CBT are not well described in the literature. In the present study, we present our experience of new-onset allergies in long-term survivors after CBT. METHODS: After an initial patient had a severe peanut allergic reaction after CBT, all CBT patients were prospectively followed for new allergy development. Fifty patients received CBT between March 2006 and June 2011. RESULTS: The median follow-up after CBT was 447 days (range, 12-2022). At the time of analysis, 30 patients were alive, with 3-year survival of 55.5%; median follow-up of surviving patients was 910 days (range, 68-2022). The allergic syndrome developed in five patients, with the cumulative incidence of new allergies at 2 years of 18.4% (95% confidence interval, 10.8-26). The median time to onset of new allergy after transplantation was 298 days (range, 250-809). CONCLUSIONS: Allergy development has been linked to a delayed maturation of the immune system in several studies. We present the first case series of patients who had new allergies after CBT. Further study of this novel complication as well as counseling of patients after CBT would be important.

Modulating microbiome-immune axis in the deployment-related chronic diseases of Veterans: report of an expert meeting.

The present report summarizes the United States Department of Veterans Affairs (VA) field-based meeting titled "Modulating microbiome-immune axis in the deployment-related chronic diseases of Veterans." Our Veteran patient population experiences a high incidence of service-related chronic physical and mental health problems, such as infection, irritable bowel syndrome (IBS), inflammatory bowel disease (IBD), various forms of hematological and non-hematological malignancies, neurologic conditions, end-stage organ failure, requiring transplantation, and posttraumatic stress disorder (PTSD). We report the views of a group of scientists who focus on the current state of scientific knowledge elucidating the mechanisms underlying the aforementioned disorders, novel therapeutic targets, and development of new approaches for clinical intervention. In conclusion, we dovetailed on four research areas of interest: 1) microbiome interaction with immune cells after hematopoietic cell and/or solid organ transplantation, graft-versus-host disease (GVHD) and graft rejection, 2) intestinal inflammation and its modification in IBD and cancer, 3) microbiome-neuron-immunity interplay in mental and physical health, and 4) microbiome-micronutrient-immune interactions during homeostasis and infectious diseases. At this VA field-based meeting, we proposed to explore a multi-disciplinary, multi-institutional, collaborative strategy to initiate a roadmap, specifically focusing on host microbiome-immune interactions among those with service-related chronic diseases to potentially identify novel and translatable therapeutic targets.

Time to explore preventive and novel therapies for bronchiolitis obliterans syndrome after allogeneic hematopoietic stem cell transplantation.

Although allogeneic hematopoietic stem cell transplant (allo-HSCT) is performed to treat otherwise incurable and fatal diseases, transplantation itself can lead to life-threatening complications due to organ damage. Pulmonary complications remain a significant barrier to the success of allo-HSCT. Lung injury, a frequent complication after allo-HSCT, and noninfectious pulmonary deaths account for a significant proportion of non-relapse mortality. Bronchiolitis obliterans syndrome (BOS) is a common and potentially devastating complication. BOS is now considered a diagnostic criterion of chronic graft-versus-host-disease (cGVHD), and National Institutes of Health (NIH) consensus has been published to establish guidelines for diagnosis and monitoring of BOS. It usually occurs within the first 2 years but may develop as late as 5 years after transplantation. Recent prevalence estimates suggest that BOS is likely underdiagnosed, and when severe BOS does occur, current treatments have been largely ineffective. Prevention and effective novel approaches remain the primary tools in the clinician's arsenal in managing BOS. This article provides an overview of the currently available and novel strategies for BOS, and we also discuss specific preventive interventions to reduce severe BOS after allo-HSCT. Therapeutic trials continue to be needed for this orphan disease.

Overview of approved CAR-T therapies, ongoing clinical trials, and its impact on clinical practice.

In recent years, we have seen rapid expansion of chimeric antigen receptor T-cell (CAR-T) therapies in multiple malignancies. CAR-T therapy has profoundly altered the treatment landscape of non-Hodgkin lymphoma, B-cell acute lymphoblastic leukemia, and multiple myeloma. Currently available CD19 and B-cell maturation antigen-directed CAR-T therapies have shown high overall response rate and durable remissions in patients who have failed standard therapies. Multiple studies are underway exploring the role of CAR-T-cell therapy as earlier line of treatment. In high-grade B-cell lymphoma, CD19 CAR-T therapy may replace autologous hematopoietic cell transplantation as second line therapy in near future. CAR-T-cell therapy targeting novel tumor-associated antigens will help expand utility of this treatment modality in other hematological malignancies. It may also help overcome limitations of currently approved CAR-T-cell therapies. In this review, we have provided an overview of currently approved CAR-T therapies and upcoming clinical trials which may potentially impact the clinical practice.

Role of bridging therapy during chimeric antigen receptor T cell therapy.

Chimeric antigen receptor (CAR) T-cell therapy has been approved for use in several relapsed/refractory hematologic malignancies and has significantly improved outcomes for these diseases. A number of different CAR T products are now being used in clinical practice and have demonstrated excellent outcomes to those in clinical trials. However, increased real-world use of CAR T therapy has uncovered a number of barriers that can lead to significant delays in treatment. As a result, bridging therapy has become a widely used tool to stabilize or debulk disease between leukapheresis and CAR T cell administration. Here we review the available data regarding bridging therapy, with a focus on patient selection, choice of therapy, timing of therapy, and potential pitfalls.

CAR T cell therapy in solid tumors: A review of current clinical trials.

Chimeric antigen receptor (CAR) T cell therapy has made tremendous strides in the arena of hematological malignancies with approved therapies in certain leukemias, lymphomas, and recently myeloma with overall highly favorable response rates. While numerous clinical studies are still ongoing for hematological malignancies, research is developing to translate the feasibility of CAR T therapy in solid organ malignancies. Unfortunately, the majority of diagnosed cancers are primarily solid tumors. Thus, a highly unmet clinical need for further research and development exists in this field. This review article highlights currently active clinical trials and a few pertinent preclinical studies involving CAR T cell therapy in solid tumors while briefly discussing study outcomes and potential key targets that may allow for the feasibility of this therapy option. Finally, we mention critical challenges existing in the solid tumor environment and discuss developing strategies that may potentially overcome the existing barriers to CAR T cell progress in solid tumors.

Reduction in the Prevalence of Thrombotic Events in Sickle Cell Disease after Allogeneic Hematopoietic Transplantation.

Thrombosis is a recognized complication in sickle cell disease (SCD). Allogeneic hematopoietic cell transplantation (allo-HCT) remains the sole curative option for patients with severe SCD phenotypes. Data describing the effects of allo-HCT on recurrent thrombotic events (venous and arterial events) are limited, however. We evaluated 31 patients with SCD who underwent allo-HCT with a median follow-up of 34.5 months (range, 13 to 115) post-transplantation. No patient continued anticoagulation or antiplatelet therapy after allo-HCT. There was an absolute difference of 32% (95% confidence interval [CI], 12.3% to 32.2%; P = .002) in the prevalence of venous thromboembolic (VTE) events before and after allo-HSCT. In addition, there was an absolute difference of 38.5% (95% CI, 10.63 to 45.96; P = .006) in the number of ischemic cerebrovascular accidents (CVAs) occurring before and after allo-HSCT. Patients with severe SCD who undergo allo-HCT are less likely to develop recurrent thrombotic events compared with a control cohort of patients matched for age and genotype (odds ratio, 0.22; 95% CI, 0.058 to 0.83; P = .025). Following curative therapy with allo-HCT, there is a reduction in recurrent arterial and venous thrombosis in patients with severe SCD phenotypes.

New-onset post-transplant diabetes mellitus after haploidentical hematopoietic cell transplant with post-transplant cyclophosphamide.

Haploidentical hematopoietic cell transplant (haplo-HCT) with post-transplant cyclophosphamide (PTCY) is utilized for patients with hematological disorders but without conventional donors. The effects of new-onset post-transplant diabetes mellitus (PTDM) following haplo-HCT are unknown. We examined PTDM incidence and outcomes after haplo-HCT with PTCY. Patients without diabetes receiving haplo-HCT (n=64) were analyzed for PTDM diagnosis (defined as blood glucose≥ 200 mg/dL). By day 100, 14 (22%) patients developed PTDM (median, 18 days). Hyperglycemia (blood glucose ≥ 200 mg/dL) preceded corticosteroids in 11 (79%) individuals. PTDM patients had increased death/relapse (p=0.029). PTDM occurs frequently, precedes corticosteroids, and leads to inferior outcomes following haplo-HCT. PTDM prophylaxis/treatment may improve HCT survival.