Relapse after Allogeneic Stem Cell Transplantation of Acute Myelogenous Leukemia and Myelodysplastic Syndrome and the Importance of Second Cellular Therapy

Patients with acute myelogenous leukemia (AML) or myelodysplastic syndrome (MDS) who relapse after allogeneic hematopoietic cell transplantation (allo-HCT) generally have poor overall survival (OS). Interventions that result in improved OS after relapse are not well established. The efficacy of second cellular therapy and specific indications are matters of debate. This study was conducted to evaluate factors associated with postrelapse survival and the efficacy of a second course of cellular therapy. We retrospectively analyzed consecutive patients with AML and MDS who underwent a first allo-HCT between 2010 and 2017 at our center but subsequently relapsed. One hundred and four patients with AML and 44 patients with MDS were included (total n = 148). Bone marrow (BM) and peripheral blood stem cell grafts were either unmodified or T cell-depleted (TCD) by CD34⁺ selection ex vivo. Forty-five patients (30.4%) received a second cellular therapy after relapse, either a second allo-HCT (n = 28; 18.9%) or donor leukocyte infusion (DLI) (n = 17; 11.5%). The median age at transplantation was 60 years (range, 24 to 78 years). The median time to relapse (TTR) after transplantation was 6.5 months (range, 1 to 60.9 months), and the ensuing median OS was 6 months (95% confidence interval [CI], 4.8 to 8.9 months). In univariable analysis, longer TTR, relapse type (measurable residual disease versus morphologic), relapse occurring in the most recent years, and receipt of cellular therapy after relapse were associated with better outcomes, whereas adverse cytogenetics and/or abnormality of TP53, as well as NPM1 mutation in patients with AML, were associated with adverse outcomes. Relapse type, year of relapse, and a variable resulting from the combination of TTR and receipt of second cellular therapy remained significantly associated with postrelapse survival in multivariable analysis. In a separate multivariable model, adjusted only for TTR, relapse type, and receipt of second cellular therapy, an adverse effect of NPM1 mutation on survival was confirmed. We could not show an effect of post-transplantation maintenance on survival after relapse. In both univariable and multivariable analysis, we found a positive association for second cellular therapy with survival after relapse in patients who relapsed early (<6 months) after allo-HCT and a similar trend in patients who relapsed late (>12 months) after transplantation. Two-year OS after a second cellular therapy was 44.9% (95% CI, 28.5% to 61.4%), and it was significantly better in patients with <5% BM blasts before cell infusion. We could not show different effects on survival after second cellular therapy for DLI versus second allo-HCT in univariable analysis. Survival after relapse is improving over time, but this remains a challenging event, especially for patients who relapse early after transplantation. We found that a second cellular therapy could offer a benefit even in these cases. Nonetheless, more research is needed to clarify the most appropriate treatment choices after relapse. These are probably driven by underlying genetic and immunologic conditions, which should be the focus of future studies.

Oral Proteasome Inhibitor Ixazomib for Switch-Maintenance Prophylaxis of Recurrent or Late Acute and Chronic Graft-versus-Host Disease after Day 100 in Allogeneic Stem Cell Transplantation

Graft-versus-host disease (GVHD) is a frequent complication in the first year after allogeneic stem cell transplantation (allo-HCT). Recipients of reduced-intensity (RI) or nonmyeloablative (NMA) conditioning combined with calcineurin inhibitor (CNI)-based GVHD prophylaxis frequently develop GVHD in the context of immunosuppression taper. Ixazomib is an oral proteasome inhibitor with a wide safety profile that has demonstrated immunomodulatory properties, inhibition of pro-inflammatory cytokines, and anti-tumor activity. We hypothesized that switch-maintenance GVHD prophylaxis using ixazomib would facilitate CNI taper without increased GVHD frequency and severity while maintaining graft-versus-tumor (GVT) effect and an acceptable safety profile. We conducted an open-label, prospective, single-center pilot study in patients with hematologic malignancies who received an RI or NMA conditioning and CNI-based GVHD prophylaxis that were within day 100 to 150 after HCT (n = 18). Patients were treated with ixazomib once weekly on a 28-day cycle (3 weeks on, 1 week off). Treatment was safe; most adverse events were grade 1 or 2, with cytopenia and elevation in transaminases the most common. Five patients were removed from the study because of toxicity or side effects. Only 5 of 18 patients developed GVHD during the study, and its severity was driven by acute manifestations while chronic involvement was mild. The cumulative incidence of grade II-IV acute and chronic GVHD at 1-year after HCT was 33% (95% confidence interval [CI], 13-55). No patients died during the study, and only 1 had malignant relapse. An additional patient relapsed after completion of the study but within 1 year after HCT. The probability of progression-free survival and GVHD-free/relapse-free survival (composite endpoint) at 1 year were 89% (95% CI, 75-100) and 78% (95% CI, 61-100), respectively. Immune reconstitution analysis showed a rapid and sustained recovery in T-cell subpopulations and B cell reconstitution, and vaccine response in a subset of patients demonstrated continuing or de novo positive protective antibody titers. This study demonstrated low incidence of recurrent and late acute and chronic GVHD within 1 year after HCT possible associated with switch-maintenance GVHD prophylaxis using ixazomib. This approach allowed for CNI taper while preserving GVT effect, without aggravating GVHD. Our findings support further development of this approach and provide a proof-of-concept for switch-maintenance GVHD prophylaxis.

Outcomes of adult T-Cell leukemia/lymphoma with allogeneic stem cell transplantation: single-institution experience

Few publications exist concerning allogeneic hematopoietic cell transplant (alloHCT) outcomes in non-Japanese patients with HTLV-1-associated ATLL. We detail the patient and disease characteristics, transplant approach, and clinical outcomes in 17 patients with ATLL at our institution who underwent alloHCT. We report favorable outcomes, with 8/17 in ongoing remission, 2/17 with prolonged (>6 years) disease-free survival, and a low incidence of transplant-related mortality (2/17). These results validate the feasibility and efficacy of alloHCT in non-Japanese patients with ATLL.

Combining the Disease Risk Index and Hematopoietic Cell Transplant Co-Morbidity Index provides a comprehensive prognostic model for CD34+-selected allogeneic transplantation

T cell depletion by CD34⁺ cell selection of hematopoietic stem cell allografts ex vivo reduces the incidence and severity of GvHD, without increased risk of relapse in patients with acute leukemia in remission or MDS. The optimal candidate for CD34⁺-selected HCT remains unknown, however.

OBJECTIVE

To determine outcomes based on both disease- and patient-specific factors, we evaluated a prognostic model combining the Disease Risk Index (DRI) and Hematopoietic Cell Transplantation Comorbidity Index (HCT-CI), an approach recently shown to predicted overall survival in a broad population of allograft recipients (1).

METHODS

This was a retrospective analysis of 506 adult recipients of first allogeneic HCT with CD34+ selected PBSCs from 7/8- or 8/8-matched donors for AML (n = 290), ALL (n = 72), or MDS (n = 144). The Kaplan-Meier method estimated OS and RFS. The cumulative incidence method for competing risks estimated relapse and non-relapse mortality (NRM). We evaluated the univariate association between variables of interest and OS and RFS using the log-rank test. Cox regression models assessed the adjusted effect of covariates on OS/RFS.

RESULTS

Stratification of patients based on a composite of DRI (low/intermediate vs. high/very high) and HCT-CI (0-2 vs. ≥ 3) revealed differences in OS and RFS between the 4 groups. Compared with reference groups of patients with low/intermediate DRI and low or high HCT-CI, those with high DRI had a greater risk of death (HR 2.30; 95% CI 1.39, 3.81) and relapse or death (HR 2.50; 95% CI 1.55, 4.05) than patients with any HCT-CI but low/intermediate DRI (HR death 1.80; 95% CI 1.34, 2.43; HR relapse/death 1.68; 95% CI 1.26, 2.24).

CONCLUSIONS AND CLINICAL IMPLICATIONS

A model combining DRI and HCT-CI predicted survival after CD34⁺ cell-selected HCT. Application of this combined model to other cohorts, both in retrospective analyses and prospective trials, will enhance clinical decision making and patient selection for different transplant approaches.

DATA AVAILABILITY STATEMENT

The data that support the findings of this study are available on request from the corresponding author, C Cho. In order to protect the privacy of research participants, the data are not publicly available.

High progression-free survival after intermediate intensity double unit cord blood transplantation in adults

Cord blood transplantation (CBT) after high intensity or nonmyeloablative conditioning has limitations. We investigated cyclosporine-A/mycophenolate mofetil-based intermediate intensity (cyclophosphamide 50 mg/kg, fludarabine 150 mg/m2, thiotepa 10 mg/kg, total body irradiation 400 cGy) unmanipulated double-unit CBT (dCBT) with prioritization of unit quality and CD34+ cell dose in graft selection. Ninety adults (median age, 47 years [range, 21-63]; median hematopoietic cell transplantation comorbidity index, 2 [range, 0-8]; 61 [68%] acute leukemia) received double-unit grafts (median CD34+ cell dose, 1.3 × 105/kg per unit [range, 0.2-8.3]; median donor-recipient human leukocyte antigen (HLA) match, 5/8 [range 3-7/8]). The cumulative incidences of sustained CB engraftment, day 180 grade III-IV acute, and 3-year chronic graft-versus-host disease were 99%, 24%, and 7%, respectively. Three-year transplant-related mortality (TRM) and relapse incidences were 15% and 9%, respectively. Three-year overall survival (OS) is 82%, and progression-free survival (PFS) is 76%. Younger age and higher engrafting unit CD34+ cell dose both improved TRM and OS, although neither impacted PFS. Engrafting unit-recipient HLA match was not associated with any outcome with a 3-year PFS of 79% in 39 patients engrafting with 3-4/8 HLA-matched units. In 52 remission acute leukemia patients, there was no association between minimal residual disease (MRD) and 3-year PFS: MRD negative of 88% vs MRD positive of 77% (P = .375). Intermediate intensity dCBT is associated with high PFS. Use of highly HLA mismatched and unmanipulated grafts permits wide application of this therapy, and the low relapse rates support robust graft-versus-leukemia effects even in patients with MRD.

The microbe-derived short-chain fatty acids butyrate and propionate are associated with protection from chronic GVHD

Studies of the relationship between the gastrointestinal microbiota and outcomes in allogeneic hematopoietic stem cell transplantation (allo-HCT) have thus far largely focused on early complications, predominantly infection and acute graft-versus-host disease (GVHD). We examined the potential relationship of the microbiome with chronic GVHD (cGVHD) by analyzing stool and plasma samples collected late after allo-HCT using a case-control study design. We found lower circulating concentrations of the microbe-derived short-chain fatty acids (SCFAs) propionate and butyrate in day 100 plasma samples from patients who developed cGVHD, compared with those who remained free of this complication, in the initial case-control cohort of transplant patients and in a further cross-sectional cohort from an independent transplant center. An additional cross-sectional patient cohort from a third transplant center was analyzed; however, serum (rather than plasma) was available, and the differences in SCFAs observed in the plasma samples were not recapitulated. In sum, our findings from the primary case-control cohort and 1 of 2 cross-sectional cohorts explored suggest that the gastrointestinal microbiome may exert immunomodulatory effects in allo-HCT patients at least in part due to control of systemic concentrations of microbe-derived SCFAs.

Engraftment kinetics after transplantation of double unit cord blood grafts combined with haplo-identical CD34+ cells without antithymocyte globulin

Double unit cord blood (dCB) transplantation (dCBT) is associated with high engraftment rates but delayed myeloid recovery. We investigated adding haplo-identical CD34+ cells to dCB grafts to facilitate early haplo-identical donor-derived neutrophil recovery (optimal bridging) prior to CB engraftment. Seventy-eight adults underwent myeloablation with cyclosporine-A/mycophenolate mofetil immunoprophylaxis (no antithymocyte globulin, ATG). CB units (median CD34+ dose 1.1 × 10⁵/kg/unit) had a median 5/8 unit-recipient human leukocyte antigen (HLA)-match. Haplo-identical grafts had a median CD34+ dose of 5.2 × 10⁶/kg. Of 77 evaluable patients, 75 had sustained CB engraftment that was mediated by a dominant unit and heralded by dominant unit-derived T cells. Optimal haplo-identical donor-derived myeloid bridging was observed in 34/77 (44%) patients (median recovery 12 days). Other engrafting patients had transient bridging with second nadir preceding CB engraftment (20/77 (26%), median first recovery 12 and second 26.5 days) or no bridge (21/77 (27%), median recovery 25 days). The 2 (3%) remaining patients had graft failure. Higher haplo-CD34+ dose and better dominant unit-haplo-CD34+ HLA-match significantly improved the likelihood of optimal bridging. Optimally bridged patients were discharged earlier (median 28 versus 36 days). ATG-free haplo-dCBT can speed neutrophil recovery but successful bridging is not guaranteed due to rapid haplo-identical graft rejection.

Intestinal dysbiosis predicts lower gastrointestinal tract acute graft-versus-host (aGVHD) disease development

Introduction

aGVHD is a major complication after hematopoietic cell transplantation (HCT) and is driven by alloimmune targeting of intestine, liver, and skin. As aGVHD has been linked to intestinal dysbiosis and the majority of the intestinal microbiota biomass resides within the colon, we hypothesized that certain microbiota features confer protection to the lower GI tract.

Methods

We evaluated 16S stool profiles of 849 samples from 215 recipients of unmodified allo-HCT. Patients were classified in four groups according to aGVHD organ involvement: upper GI only (UGI, n =53), lower GI with/without upper GI (LGI, n=56), no GI involvement (non-GI, n=30) and no GVHD (n=76). Samples were grouped into pre-onset (day −20 to 0) and post-onset (day 1 to 20) aGVHD.

Results

Pre-onset, LGI patients showed a decreased strict anaerobes to facultative anaerobes (A/F) ratio vs. non-GI (p=0.036) and a low A/F ratio was associated with reduced overall survival (p=0.004) from aGVHD onset. After aGVHD onset, LGI patients had reduced microbial alpha diversity, abundance of predicted butyrate-producing (BP) bacteria and A/F ratio vs. non-GI patients (p=0.017, p=0.003 and p=0.020, respectively). LGI patients also had less BP bacteria, members of genus Blautia, and lower A/F ratio (p=0.0.017, p=0.008 and p=0.048 respectively) vs. UGI patients.

Conclusions

LGI patients had distinct microbial features consistent with dysbiosis, when compared to UGI and non-GI patients. Importantly, we observed microbiota disruption in the 20 days preceding aGVHD onset, suggesting a predictive marker of LGI aGVHD and an association with overall survival, which have potential practical implications for GVHD risk stratification and therapeutic interventions.

Graft vs. host disease leads to elimination of tissue-resident innate lymphoid cells following experimental and clinical allogeneic transplantation

Innate lymphoid cells (ILCs) are associated with protective mucosal responses after allogeneic bone marrow transplantation (allo-BMT). However, the specific in vivo roles of ILCs after BMT remain unclear. We thus sought to characterize the kinetics and significance of ILC reconstitution after allo-BMT.

In a sex-mismatched acute graft-vs-host-disease (GVHD) model, depletion of recipient ILCs induced significantly worse systemic signs of GVHD, as well as increased thymic injury and intestinal pathology, indicating a contributory role for ILCs in tissue protection post-BMT.

Analysis of ILCs in distinct GVHD target organs after T-cell-depleted BMT demonstrated a high frequency of NK cells and ILC1s in the liver, a higher proportion of ILC2s in lungs, and a higher proportion of ILC3s in the small intestine post-transplant in the absence of GVHD. For all tissues analyzed, the majority of ILCs were host-derived. In contrast, in the presence of GVHD, all ILC subsets were significantly reduced in all tissues analyzed. Furthermore, ILC precursors were significantly reduced in the bone marrow of mice with GVHD, suggesting that alloreactive immunity can impair ILC reconstitution by targeting both mature ILCs and their developmental niche.

To examine the clinical relevance of these findings, human ILCs were analyzed by FACS of lamina propria lymphocytes isolated from patient duodenal biopsy specimens obtained to evaluate symptoms of acute GI GVHD. Consistent with experimental findings, duodenal ILC frequencies were significantly lower in patients with histologic evidence of GVHD.

In conclusion, tissue-resident ILCs contribute to tissue protection after allo-BMT, but GVHD leads to ILC elimination and impairs their reconstitution.

Characteristics and Impact of Post-Transplant Interdisciplinary Palliative Care Consultation in Older Allogeneic Hematopoietic Cell Transplant Recipients

Context and Objectives: The myriad of benefits of early palliative care (PC) integration in oncology are well established, and emerging evidence suggests that PC improves symptom burden, mood, and quality of life for hematopoietic cell transplant (HCT) recipients. Specific impact of PC consultation on outcomes of older allogeneic HCT (allo-HCT) recipients, a historically high-risk population vulnerable to transplant-related complications and mortality, has not been explored. Design and Methods: In this single institution, retrospective analysis of 527 first allo-HCT recipients aged ≥60 years, we characterized 75 patients who had received post-HCT PC consultation and its association with geriatric vulnerabilities identified by pre-HCT geriatric assessment. We also examined end-of-life care outcomes among patients who died within one-year of allo-hematopoietic cell transplantation. Results: In multivariate analysis, higher disease risk, female gender, and, importantly, pre-HCT functional limitation (hazard ratio 2.35, 95% confidence interval, 1.35-4.09, p = 0.003) were associated with post-HCT PC utilization. Within one-year of hematopoietic cell transplantation, 127 patients died; among those, recipients of early PC consultation had significantly higher rates of hospice enrollment (25% vs. 9%, p = 0.019) and lower rates of hospital death (71% vs. 90%, p = 0.013), intensive care unit admission (44% vs. 75%, p = 0.001), and high-intensity medical care in last 30 days of life (46% vs. 77%, p = 0.001). Conclusions: Our results highlight important pre-HCT risk factors associated with increased PC needs posthematopoietic cell transplantation and benefits of PC involvement for older allo-HCT recipients at the end of life. Prospective studies should examine the optimal timing of PC consultation and its multidimensional benefits for older allo-HCT patients.

Microbiota as Predictor of Mortality in Allogeneic Hematopoietic-Cell Transplantation

BACKGROUND

Relationships between microbiota composition and clinical outcomes after allogeneic hematopoietic-cell transplantation have been described in single-center studies. Geographic variations in the composition of human microbial communities and differences in clinical practices across institutions raise the question of whether these associations are generalizable.

METHODS

The microbiota composition of fecal samples obtained from patients who were undergoing allogeneic hematopoietic-cell transplantation at four centers was profiled by means of 16S ribosomal RNA gene sequencing. In an observational study, we examined associations between microbiota diversity and mortality using Cox proportional-hazards analysis. For stratification of the cohorts into higher- and lower-diversity groups, the median diversity value that was observed at the study center in New York was used. In the analysis of independent cohorts, the New York center was cohort 1, and three centers in Germany, Japan, and North Carolina composed cohort 2. Cohort 1 and subgroups within it were analyzed for additional outcomes, including transplantation-related death.

RESULTS

We profiled 8767 fecal samples obtained from 1362 patients undergoing allogeneic hematopoietic-cell transplantation at the four centers. We observed patterns of microbiota disruption characterized by loss of diversity and domination by single taxa. Higher diversity of intestinal microbiota was associated with a lower risk of death in independent cohorts (cohort 1: 104 deaths among 354 patients in the higher-diversity group vs. 136 deaths among 350 patients in the lower-diversity group; adjusted hazard ratio, 0.71; 95% confidence interval [CI], 0.55 to 0.92; cohort 2: 18 deaths among 87 patients in the higher-diversity group vs. 35 deaths among 92 patients in the lower-diversity group; adjusted hazard ratio, 0.49; 95% CI, 0.27 to 0.90). Subgroup analyses identified an association between lower intestinal diversity and higher risks of transplantation-related death and death attributable to graft-versus-host disease. Baseline samples obtained before transplantation already showed evidence of microbiome disruption, and lower diversity before transplantation was associated with poor survival.

CONCLUSIONS

Patterns of microbiota disruption during allogeneic hematopoietic-cell transplantation were similar across transplantation centers and geographic locations; patterns were characterized by loss of diversity and domination by single taxa. Higher diversity of intestinal microbiota at the time of neutrophil engraftment was associated with lower mortality. (Funded by the National Cancer Institute and others.).

Lactose drives Enterococcus expansion to promote graft-versus-host disease

Disruption of intestinal microbial communities appears to underlie many human illnesses, but the mechanisms that promote this dysbiosis and its adverse consequences are poorly understood. In patients who received allogeneic hematopoietic cell transplantation (allo-HCT), we describe a high incidence of enterococcal expansion, which was associated with graft-versus-host disease (GVHD) and mortality. We found that Enterococcus also expands in the mouse gastrointestinal tract after allo-HCT and exacerbates disease severity in gnotobiotic models. Enterococcus growth is dependent on the disaccharide lactose, and dietary lactose depletion attenuates Enterococcus outgrowth and reduces the severity of GVHD in mice. Allo-HCT patients carrying lactose-nonabsorber genotypes showed compromised clearance of postantibiotic Enterococcus domination. We report lactose as a common nutrient that drives expansion of a commensal bacterium that exacerbates an intestinal and systemic inflammatory disease.

Establishing a standardized system for review and adjudication of chronic graft-vs-host disease data in accordance with the National Institutes Consensus criteria

GVHD is a frequent complication following allo-HCT. The NIH consensus group established new guidelines for the evaluation of chronic GVHD. However, GVHD assessment remains challenging due its complexity and requirement for laborious evaluation. We, therefore, established a standardized approach for the assessment of chronic GVHD in accordance with the NCC guidelines. At a single institution, all allograft recipients were evaluated for GVHD within the first-year post allo-HCT following a 3-step workflow (real-time assessment, consensus review, and documentation). A GVHD adjudication committee was created and a dynamic electronic GVHD data capture form was developed guiding the clinician through a comprehensive review of systems following the NCC guidelines. We found that the assessment and reporting of GVHD reached 100% compliance. The establishment of an institutional GVHD adjudication committee enabled standardized assessment of GVHD. Our workflow can be adopted by other centers to create a similar framework for dedicated GVHD evaluation.