Defining and Grading Infections in Clinical Trials Involving Hematopoietic Cell Transplantation: A Report From the BMT CTN Infectious Disease Technical Committee

The Blood and Marrow Transplant Clinical Trials Network (BMT-CTN) was established in 2001 to conduct large multi-institutional clinical trials addressing important issues towards improving the outcomes of HCT and other cellular therapies. Trials conducted by the network investigating new advances in HCT and cellular therapy not only assess efficacy but require careful capturing and severity assessment of adverse events and toxicities. Adverse infectious events in cancer clinical trials are typically graded according to the National Cancer Institute's Common Terminology Criteria for Adverse Events (CTCAE). However, there are limitations to this framework as it relates to HCT given the associated immunodeficiency and delayed immune reconstitution. The BMT-CTN Infection Grading System is a monitoring tool developed by the BMT CTN to capture and monitor infectious complications and differs from the CTCAE by its classification of infections based on their potential impact on morbidity and mortality for HCT recipients. Here we offer a report from the BMT CTN Infectious Disease Technical Committee regarding the rationale, development, and revising of BMT-CTN Infection Grading System and future directions as it applies to future clinical trials involving HCT and cellular therapy recipients.

Anti-CD30 CAR T cells as consolidation after autologous haematopoietic stem-cell transplantation in patients with high-risk CD30+ lymphoma: a phase 1 study

BACKGROUND

Chimeric antigen receptor (CAR) T cells targeting CD30 are safe and have promising activity when preceded by lymphodepleting chemotherapy. We aimed to determine the safety of anti-CD30 CAR T cells as consolidation after autologous haematopoietic stem-cell transplantation (HSCT) in patients with CD30+ lymphoma at high risk of relapse.

METHODS

This phase 1 dose-escalation study was performed at two sites in the USA. Patients aged 3 years and older, with classical Hodgkin lymphoma or non-Hodgkin lymphoma with CD30+ disease documented by immunohistochemistry, and a Karnofsky performance score of more than 60% planned for autologous HSCT were eligible if they were considered high risk for relapse as defined by primary refractory disease or relapse within 12 months of initial therapy or extranodal involvement at the start of pre-transplantation salvage therapy. Patients received a single infusion of CAR T cells (2 × 107 CAR T cells per m2, 1 × 108 CAR T cells per m2, or 2 × 108 CAR T cells per m2) as consolidation after trilineage haematopoietic engraftment (defined as absolute neutrophil count ≥500 cells per μL for 3 days, platelet count ≥25 × 109 platelets per L without transfusion for 5 days, and haemoglobin ≥8 g/dL without transfusion for 5 days) following carmustine, etoposide, cytarabine, and melphalan (BEAM) and HSCT. The primary endpoint was the determination of the maximum tolerated dose, which was based on the rate of dose-limiting toxicity in patients who received CAR T-cell infusion. This study is registered with ClinicalTrials.gov (NCT02663297) and enrolment is complete.

FINDINGS

Between June 7, 2016, and Nov 30, 2020, 21 patients were enrolled and 18 patients (11 with Hodgkin lymphoma, six with T-cell lymphoma, one with grey zone lymphoma) were infused with anti-CD30 CAR T cells at a median of 22 days (range 16-44) after autologous HSCT. There were no dose-limiting toxicities observed, so the highest dose tested, 2 × 108 CAR T cells per m2, was determined to be the maximum tolerated dose. One patient had grade 1 cytokine release syndrome. The most common grade 3-4 adverse events were lymphopenia (two [11%] of 18) and leukopenia (two [11%] of 18). There were no treatment-related deaths. Two patients developed secondary malignancies approximately 2 years and 2·5 years following treatment (one stage 4 non-small cell lung cancer and one testicular cancer), but these were judged unrelated to treatment. At a median follow-up of 48·2 months (IQR 27·5-60·7) post-infusion, the median progression-free survival for all treated patients (n=18) was 32·3 months (95% CI 4·6 months to not estimable) and the median progression-free survival for treated patients with Hodgkin lymphoma (n=11) has not been reached. The median overall survival for all treated patients has not been reached.

INTERPRETATION

Anti-CD30 CAR T-cell infusion as consolidation after BEAM and autologous HSCT is safe, with low rates of toxicity and encouraging preliminary activity in patients with Hodgkin lymphoma at high risk of relapse, highlighting the need for larger studies to confirm these findings.

FUNDING

National Heart Lung and Blood Institute, University Cancer Research Fund at the Lineberger Comprehensive Cancer Center.

SARS-CoV-2 vaccination in the first year after hematopoietic cell transplant or chimeric antigen receptor T cell therapy: A prospective, multicenter, observational study (BMT CTN 2101)

Background

The optimal timing of vaccination with SARS-CoV-2 vaccines after cellular therapy is incompletely understood.

Objective

To describe humoral and cellular responses after SARS-CoV-2 vaccination initiated <4 months versus 4-12 months after cellular therapy.

Design

Multicenter prospective observational study.

Setting

34 centers in the United States.

Participants

466 allogeneic hematopoietic cell transplant (HCT; n=231), autologous HCT (n=170), or chimeric antigen receptor T cell (CAR-T cell) therapy (n=65) recipients enrolled between April 2021 and June 2022.

Interventions

SARS-CoV-2 vaccination as part of routine care.

Measurements

We obtained blood prior to and after vaccinations at up to five time points and tested for SARS-CoV-2 spike (anti-S) IgG in all participants and neutralizing antibodies for Wuhan D614G, Delta B.1.617.2, and Omicron B.1.1.529 strains, as well as SARS-CoV-2-specific T cell receptors (TCRs), in a subgroup.

Results

Anti-S IgG and neutralizing antibody responses increased with vaccination in HCT recipients irrespective of vaccine initiation timing but were unchanged in CAR-T cell recipients initiating vaccines within 4 months. Anti-S IgG ≥2,500 U/mL was correlated with high neutralizing antibody titers and attained by the last time point in 70%, 69%, and 34% of allogeneic HCT, autologous HCT, and CAR-T cell recipients, respectively. SARS-CoV-2-specific T cell responses were attained in 57%, 83%, and 58%, respectively. Humoral and cellular responses did not significantly differ among participants initiating vaccinations <4 months vs 4-12 months after cellular therapy. Pre-cellular therapy SARS-CoV-2 infection or vaccination were key predictors of post-cellular therapy anti-S IgG levels.

Limitations

The majority of participants were adults and received mRNA vaccines.

Conclusions

These data support starting mRNA SARS-CoV-2 vaccination three to four months after allogeneic HCT, autologous HCT, and CAR-T cell therapy.

Funding

National Marrow Donor Program, Leukemia and Lymphoma Society, Multiple Myeloma Research Foundation, Novartis, LabCorp, American Society for Transplantation and Cellular Therapy, Adaptive Biotechnologies, and the National Institutes of Health.

SARS-CoV-2 vaccination in the first year after allogeneic hematopoietic cell transplant: a prospective, multicentre, observational study

Background

The optimal timing for SARS-CoV-2 vaccines within the first year after allogeneic hematopoietic cell transplant (HCT) is poorly understood.

Methods

We conducted a prospective, multicentre, observational study of allogeneic HCT recipients who initiated SARS-CoV-2 vaccinations within 12 months of HCT. Participants were enrolled at 22 academic cancer centers across the United States. Participants of any age who were planning to receive a first post-HCT SARS-CoV-2 vaccine within 12 months of HCT were eligible. We obtained blood prior to and after each vaccine dose for up to four vaccine doses, with an end-of-study sample seven to nine months after enrollment. We tested for SARS-CoV-2 spike protein (anti-S) IgG; nucleocapsid protein (anti-N) IgG; neutralizing antibodies for Wuhan D614G, Delta B.1.617.2, and Omicron B.1.1.529 strains; and SARS-CoV-2-specific T-cell receptors (TCRs). The primary outcome was a comparison of anti-S IgG titers at the post-V2 time point in participants initiating vaccinations <4 months versus 4-12 months after HCT using a propensity-adjusted analysis. We also evaluated factors associated with high-level anti-S IgG titers (≥2403 U/mL) in logistic regression models.

Findings

Between April 22, 2021 and November 17, 2021, 175 allogeneic HCT recipients were enrolled in the study, of whom all but one received mRNA SARS-CoV-2 vaccines. SARS-CoV-2 anti-S IgG titers, neutralizing antibody titers, and TCR breadth and depth did not significantly differ at all tested time points following the second vaccination among those initiating vaccinations <4 months versus 4-12 months after HCT. Anti-S IgG ≥2403 U/mL correlated with neutralizing antibody levels similar to those observed in a prior study of non-immunocompromised individuals, and 57% of participants achieved anti-S IgG ≥2403 U/mL at the end-of-study time point. In models adjusted for SARS-CoV-2 infection pre-enrollment, SARS-CoV-2 vaccination pre-HCT, CD19+ B-cell count, CD4+ T-cell count, and age (as applicable to the model), vaccine initiation timing was not associated with high-level anti-S IgG titers at the post-V2, post-V3, or end-of-study time points. Notably, prior graft-versus-host-disease (GVHD) or use of immunosuppressive medications were not associated with high-level anti-S IgG titers. Grade ≥3 vaccine-associated adverse events were infrequent.

Interpretation

These data support starting mRNA SARS-CoV-2 vaccination three months after HCT, irrespective of concurrent GVHD or use of immunosuppressive medications. This is one of the largest prospective analyses of vaccination for any pathogen within the first year after allogeneic HCT and supports current guidelines for SARS-CoV-2 vaccination starting three months post-HCT. Additionally, there are few studies of mRNA vaccine formulations for other pathogens in HCT recipients, and these data provide encouraging proof-of-concept for the utility of early vaccination targeting additional pathogens with mRNA vaccine platforms.

Funding

National Marrow Donor Program, Leukemia and Lymphoma Society, Multiple Myeloma Research Foundation, Novartis, LabCorp, American Society for Transplantation and Cellular Therapy, Adaptive Biotechnologies, and the National Institutes of Health.

Real-world data showing trends and outcomes by race and ethnicity in allogeneic hematopoietic cell transplantation: a report from the Center for International Blood and Marrow Transplant Research

BACKGROUND

Use of human leukocyte antigen (HLA)-mismatched donors could enable more patients with ethnically diverse backgrounds to receive allogeneic hematopoietic cell transplantation (HCT) in the United States. However, real-world trends and outcomes following mismatched donor HCT for diverse patients remain largely undefined.

OBJECTIVE

To determine whether mismatched donor platforms have increased access to allogeneic HCT for ethnically diverse patients, particularly through the application of novel graft-versus-host disease (GvHD) prophylaxis regimens, and if outcomes for diverse patients were comparable to those of non-Hispanic White patients.

DESIGN

Observational cross-sectional study using real-world data from the Center for International Blood and Marrow Transplant Research (CIBMTR) registry. All patients receiving their first allogeneic HCT in the U.S. from 2009-2020 with focus on transplants performed in 2020 were included. Data from patients receiving allogeneic HCT using bone marrow, peripheral blood or cord blood from HLA-matched or mismatched related and unrelated donors was analyzed. Specifically, relative proportions of allogeneic HCT were generated as percent of total for donor type and for patient age, disease indication, GvHD prophylaxis, and race and ethnicity. Causes of death were summarized using frequencies, and the Kaplan-Meier estimator was used for estimating overall survival.

RESULTS

Compared to matched related donor and matched unrelated donor HCT, more ethnically diverse patients received mismatched unrelated donor, haploidentical donor, and cord blood HCT. Matched unrelated donor remains the most common donor type, but use of haploidentical donors has increased significantly over the last 5 years. Paralleling the increase in haploidentical HCT is the increased use of post-transplant cyclophosphamide (PTCy) as GvHD prophylaxis. Relative to older transplant eras, the most contemporary transplant era associates with the highest survival rates following allogeneic HCT irrespective of patient race and ethnicity. However, disease relapse remains the primary cause of death for both adult and pediatric allogeneic HCT recipients by donor type and across all patient race and ethnicity groups.

CONCLUSIONS

Ethnically diverse patients are undergoing allogeneic HCTs at higher rates largely through the use of alternative donor platforms incorporating PTCy. Maintaining access to potential life-saving allogeneic HCT using alternative donors and novel GvHD prophylaxis strategies and improving HCT outcomes, particularly disease relapse, are urgent clinical needs.

Clinical Characteristics and Outcomes of COVID-19 in Pediatric and Early Adolescent and Young Adult Hematopoietic Stem Cell Transplant Recipients: A Cohort Study

Adult hematopoietic stem cell transplantation (HSCT) recipients are at a high risk of adverse outcomes after COVID-19. Although children have had better outcomes after COVID-19 compared to adults, data on risk factors and outcomes of COVID-19 among pediatric HSCT recipients are lacking. We describe outcomes of HSCT recipients who were ≤21 years of age at COVID-19 diagnosis and were reported to the Center for International Blood and Marrow Transplant Research between March 27, 2020, and May 7, 2021. The primary outcome was overall survival after COVID-19 diagnosis. We determined risk factors of COVID-19 as a secondary outcome in a subset of allogeneic HSCT recipients. A total of 167 pediatric HSCT recipients (135 allogeneic; 32 autologous HSCT recipients) were included. Median time from HSCT to COVID-19 was 15 months (interquartile range [IQR] 7-45) for allogeneic HSCT recipients and 16 months (IQR 6-59) for autologous HSCT recipients. Median follow-up from COVID-19 diagnosis was 53 days (range 1-270) and 37 days (1-179) for allogeneic and autologous HSCT recipients, respectively. Although COVID-19 was mild in 87% (n = 146/167), 10% (n = 16/167) of patients required supplemental oxygen or mechanical ventilation. The 45-day overall survival was 95% (95% confidence interval [CI], 90-99) and 90% (74-99) for allogeneic and autologous HSCT recipients, respectively. Cox regression analysis showed that patients with a hematopoietic cell transplant comorbidity index (HCT-CI) score of 1-2 were more likely to be diagnosed with COVID-19 (hazard ratio 1.95; 95% CI, 1.03-3.69, P = .042) compared to those with an HCT-CI of 0. Pediatric and early adolescent and young adult HSCT recipients with pre-HSCT comorbidities were more likely to be diagnosed with COVID-19. Overall mortality, albeit higher than the reported general population estimates, was lower when compared with previously published data focusing on adult HSCT recipients.

Safety and Efficacy of Pembrolizumab Prior to Allogeneic Stem Cell Transplantation for Acute Myelogenous Leukemia

Programmed death 1 (PD-1) is an integral component of acute myelogenous leukemia (AML) immune evasion, chemotherapy resistance, and disease progression. PD-1 inhibitors are being investigated as treatment for AML in combination with hypomethylating agents and cytotoxic chemotherapy with encouraging findings. Although allogeneic stem cell transplantation (alloSCT) remains the most established curative treatment for patients with relapsed and refractory AML in complete remission, there are limited data on the clinical outcomes and safety of immune checkpoint inhibitors (ICIs) prior to alloSCT in AML. In the present study, we compared clinical outcomes of 9 patients with AML receiving high-dose cytarabine followed by pembrolizumab in a phase II clinical trial (NCT02768792) prior to alloSCT versus a historical control group of 18 AML patients who underwent alloSCT without prior ICI exposure. The nonparametric Jonckheere-Terpstra test was used to test for a difference in the ordered severity categories of acute graft-versus-host disease (GVHD) within 100 days of transplantation. Time-to-event estimates for overall survival and relapse-free survival were calculated using the Kaplan-Meier method and compared using a log-rank test. One-year survival was not significantly different between the treatment groups (67% versus 78%; P = .34). 100-day mortality was 0% in the ICI group versus 17% in the control group, and there was no increase in grade III-IV acute GVHD in patients treated with pembrolizumab prior to alloSCT. No chronic GVHD was seen in patients treated with pembrolizumab prior to alloSCT and who received post-transplantation cyclophosphamide (PTCy) as part of their conditioning regimen. These findings reinforce the safety and feasibility of ICI therapy prior to alloSCT in patients with AML, and suggest that PTCy may abrogate GVHD risk and severity in patients who receive ICI prior to undergoing alloSCT for AML.

Planned Granulocyte Colony-Stimulating Factor Adversely Impacts Survival after Allogeneic Hematopoietic Cell Transplantation Performed with Thymoglobulin for Myeloid Malignancy

The in vivo depletion of recipient and donor T lymphocytes using antithymocyte globulin (ATG; Thymoglobulin) is widely adopted in allogeneic hematopoietic stem cell transplantation (HCT) to reduce the incidence of both graft failure and graft-versus-host disease (GVHD). However, excess toxicity to donor lymphocytes may hamper immune reconstitution, compromising antitumor effects and increasing infection. Granulocyte-colony stimulating factor (G-CSF) administered early after HCT may increase ATG-mediated lymphotoxicity. This study aimed to investigate the effect of an interaction between ATG and post-transplantation granulocyte colony-stimulating factor (G-CSF) on allogeneic HCT outcomes, using the Center for International Blood and Marrow Transplant Research (CIBMTR) registry. We studied patients age ≥18 years with acute myelogenous leukemia (AML) and myelodysplastic syndrome (MDS) who received Thymoglobulin-containing preparative regimens for HLA-matched sibling/unrelated or mismatched unrelated donor HCT between 2010 and 2018. The effect of planned G-CSF that was started between pretransplantation day 3 and post-transplantation day 12 was studied in comparison with transplantations that did not include G-CSF. Cox regression models were built to identify risk factors associated with outcomes at 1 year after transplantation. A total of 874 patients met the study eligibility criteria, of whom 459 (53%) received planned G-CSF. HCT with planned G-CSF was associated with a significantly increased risk for nonrelapse mortality (NRM) (hazard ratio [HR] 2.03; P <.0001; 21% versus 12%) compared to HCT without G-CSF. The 6-month incidence of viral infection was higher with G-CSF (56% versus 47%; P = .007), with a particular increase in Epstein-Barr virus infections (19% versus 11%; P = .002). The observed higher NRM with planned G-CSF led to lower overall survival (HR, 1.52; P = .0005; 61% versus 72%). There was no difference in GVHD risk between the treatment groups. We performed 2 subgroup analyses showing that our findings held true in patients age ≥50 years and in centers where G-CSF was used in some, but not all, patients. In allogeneic peripheral blood HCT performed with Thymoglobulin for AML and MDS, G-CSF administered early post-transplantation resulted in a 2-fold increase in NRM and a 10% absolute decrement in survival. The use of planned G-CSF in the early post-transplantation period should be carefully considered on an individual patient basis, weighing any perceived benefits against these risks.

Standardizing Definitions of Hematopoietic Recovery, Graft Rejection, Graft Failure, Poor Graft Function, and Donor Chimerism in Allogeneic Hematopoietic Cell Transplantation: A Report on Behalf of the American Society for Transplantation and Cellular Therapy

Allogeneic hematopoietic cell transplantation (allo-HCT) is potentially curative for certain hematologic malignancies and nonmalignant diseases. The field of allo-HCT has witnessed significant advances, including broadening indications for transplantation, availability of alternative donor sources, less toxic preparative regimens, new cell manipulation techniques, and novel GVHD prevention methods, all of which have expanded the applicability of the procedure. These advances have led to clinical practice conundrums when applying traditional definitions of hematopoietic recovery, graft rejection, graft failure, poor graft function, and donor chimerism, because these may vary based on donor type, cell source, cell dose, primary disease, graft-versus-host disease (GVHD) prophylaxis, and conditioning intensity, among other variables. To address these contemporary challenges, we surveyed a panel of allo-HCT experts in an attempt to standardize these definitions. We analyzed survey responses from adult and pediatric transplantation physicians separately. Consensus was achieved for definitions of neutrophil and platelet recovery, graft rejection, graft failure, poor graft function, and donor chimerism, but not for delayed engraftment. Here we highlight the complexities associated with the management of mixed donor chimerism in malignant and nonmalignant hematologic diseases, which remains an area for future research. We recognize that there are multiple other specific, and at times complex, clinical scenarios for which clinical management must be individualized.

Genetics of HLA Peptide Presentation and Impact on Outcomes in HLA-Matched Allogeneic Hematopoietic Cell Transplantation

Minor histocompatibility antigens (mHAs), recipient-derived peptide epitopes presented on the cell surface, are known to mediate graft-versus-host disease (GVHD); however, there are no current methods to associate mHA features with GVHD risk. This deficiency is due in part to the lack of technological means to accurately predict, let alone confirm, the tremendous number of potential mHAs in each individual transplant. Previous studies have shown that different HLA molecules present varying fractions of candidate peptide epitopes; however, the genetic "distance" between HLA-matched donors and recipients is relatively constrained. From these 2 observations, it is possible that the HLA type for a donor-recipient pair (DRP) would provide a surrogate measurement of the number of predicted mHAs, which could be related to GVHD risk. Because different HLA molecules present variable numbers of peptide antigens, a predicted cumulative peptide-binding efficiency can be calculated for individual DRP based on the pair's HLA type. The purpose of this study was to test whether cumulative peptide-binding efficiency is associated with the risk of acute GVHD (aGVHD) or relapse. In this retrospective Center for International Blood and Marrow Transplant Research study, a total of 3242 HLA-matched DRPs were analyzed for predicted cumulative peptide-binding efficiency using their HLA types and were divided into tertiles based on their scores. Univariable and multivariable analyses was performed to test for associations between cumulative peptide-binding efficiency for DRPs, divided into the HLA-matched related donor (MRD) and HLA-matched unrelated donor (MUD) cohorts, and the primary outcomes of aGVHD and relapse. Secondary outcomes investigated included overall survival, disease-free survival, and transplantation-related mortality. Using a computationally generated peptidome as a test dataset, the tested series of HLA class I displayed peptide-binding frequencies ranging from 0.1% to 3.8% of the full peptidome, and HLA class II molecules had peptide-binding frequencies of 12% to 77% across the HLA-DRB1 allotypes. By increasing binding efficiency tertile, the cumulative incidence of aGVHD at 6 months for MUD patients was 41%, 41%, and 45% for HLA class I (P = .336) and 44%, 41%, and 42% for HLA class II (P = .452). The cumulative incidences of relapse at 3 years for MUD transplant recipients were 36%, 38%, and 38% for HLA class I (P = .533) and 37%, 37%, and 38% for HLA class II (P = .896). The findings were similar for MRD transplant recipients. Multivariable analysis did not identify any impact of peptide-binding efficiency on aGVHD or relapse in MUD or MRD transplant recipients. Whereas GVHD is mediated by minor antigen mismatches in the context of HLA-matched allo-HCT, peptide-binding efficiency, which was used as a surrogate measurement for predicted number of binding antigens, did not provide additional clinical information for GVHD risk assessment. The negative result may be due to the limitations of this surrogate marker, or it is possible that GVHD is driven by a subset of immunogenic mHAs. Further research should be directed at direct mHA epitope and immunogenicity prediction.

Clinical characteristics and outcomes of COVID-19 in haematopoietic stem-cell transplantation recipients: an observational cohort study

Background

Haematopoietic stem-cell transplantation (HSCT) recipients are considered at high risk of poor outcomes after COVID-19 on the basis of their immunosuppressed status, but data from large studies in HSCT recipients are lacking. This study describes the characteristics and outcomes of HSCT recipients after developing COVID-19.

Methods

In response to the pandemic, the Center for International Blood and Marrow Transplant Research (CIBMTR) implemented a special form for COVID-19-related data capture on March 27, 2020. All patients—irrespective of age, diagnosis, donor type, graft source, or conditioning regimens—were included in the analysis with data cutoff of Aug 12, 2020. The main outcome was overall survival 30 days after a COVID-19 diagnosis. Overall survival probabilities were calculated using Kaplan-Meier estimator. Factors associated with mortality after COVID-19 diagnosis were examined using Cox proportional hazard models.

Findings

318 HSCT recipients diagnosed with COVID-19 were reported to the CIBMTR. The median time from HSCT to COVID-19 diagnosis was 17 months (IQR 8–46) for allogeneic HSCT recipients and 23 months (8–51) for autologous HSCT recipients. The median follow-up of survivors was 21 days (IQR 8–41) for allogeneic HSCT recipients and 25 days (12–35) for autologous HSCT recipients. 34 (18%) of 184 allogeneic HSCT recipients were receiving immunosuppression within 6 months of COVID-19 diagnosis. Disease severity was mild in 155 (49%) of 318 patients, while severe disease requiring mechanical ventilation occurred in 45 (14%) of 318 patients—ie, 28 (15%) of 184 allogeneic HSCT recipients and 17 (13%) of 134 autologous HSCT recipients. At 30 days after the diagnosis of COVID-19, overall survival was 68% (95% CI 58–77) for recipients of allogeneic HSCT and 67% (55–78) for recipients of autologous HSCT. Age 50 years or older (hazard ratio 2·53, 95% CI 1·16–5·52; p=0·020); male sex (3·53; 1·44–8·67; p=0·006), and development of COVID-19 within 12 months of transplantation (2·67, 1·33–5·36; p=0·005) were associated with a higher risk of mortality among allogeneic HSCT recipients, and a disease indication of lymphoma was associated with a higher risk of mortality compared with plasma cell disorder or myeloma (2·41, [1·08–5·38]; p=0·033) in autologous HSCT recipients.

Interpretation

Recipients of autologous and allogeneic HSCT who develop COVID-19 have poor overall survival. These data emphasise the need for stringent surveillance and aggressive treatment measures in HSCT recipients who develop COVID-19.

Funding

American Society of Hematology; Leukemia and Lymphoma Society; National Cancer Institute; National Heart, Lung and Blood Institute; National Institute of Allergy and Infectious Diseases; National Institutes of Health; National Cancer Institute; Health Resources and Services Administration; Office of Naval Research.

Bloodstream Infection Due to Vancomycin-resistant Enterococcus Is Associated With Increased Mortality After Hematopoietic Cell Transplantation for Acute Leukemia and Myelodysplastic Syndrome: A Multicenter, Retrospective Cohort Study

BACKGROUND

We examined the impact of vancomycin-resistant Enterococcus (VRE) bloodstream infection (BSI) on outcomes of allogeneic hematopoietic cell transplantation (HCT) utilizing the Center for International Blood and Marrow Transplant Research database.

METHODS

Adult and pediatric patients (N = 7128) who underwent first HCT for acute leukemia or myelodysplastic syndrome from 2008 through 2012 were analyzed as 3 groups-VRE BSI, non-VRE BSI, without BSI-according to BSI status at 100 days (D100) after allogeneic HCT. Multivariable models examined the effect of VRE BSI for overall survival (OS) and nonrelapse mortality (NRM) at 1 year.

RESULTS

Of 7128 patients, 258 (3.2%) had VRE BSI, 2398 (33.6%) had non-VRE BSI, and 4472 (63%) had no BSI. The median time to VRE BSI and non-VRE BSI were D11 and D15, respectively. Compared with non-VRE BSI patients, VRE BSI patients were older, had advanced-stage acute leukemia, and received umbilical cord blood (UCB) allografts. In multivariable models, VRE BSI was associated with lower OS (relative risk [RR], 2.9;(99% confidence interval [CI], 2.2-3.7) and increased NRM (RR, 4.7; 99% CI, 3.6-6.2) (P < .0001) for both. Other predictors for worse OS and increased NRM were non-VRE BSI, older age, advanced disease stage, UCB allograft, - mismatch, comorbidity index ≥3, and cytomegalovirus seropositivity (P < .001 for all variables).

CONCLUSIONS

VRE BSI is associated with lowest OS and highest NRM compared with patients without BSI or non-VRE BSI. Novel interventions that address the pathophysiology of VRE BSI have the potential of improving survival after HCT.

Current Use of and Trends in Hematopoietic Cell Transplantation in the United States

Hematopoietic cell transplantation (HCT) is a well-established treatment to control and/or cure many malignant and nonmalignant diseases involving the hematopoietic system and some solid tumors. We report information about HCT procedures performed in the United States in 2018 and analyze trends and outcomes of HCT as reported to the Center for International Blood and Marrow Transplant Research (CIBMTR). Overall, compared with 2017, the number of allogeneic HCTs performed in the United States increased by 1%, and the number of autologous HCTs decreased by 5%. Key findings are fewer autologous HCTs performed for non-Hodgkin lymphoma and increasing numbers of haploidentical HCTs, nearly all of which use post-transplantation cyclophosphamide for graft-versus-host disease prophylaxis. There is a continuing increase in HCT in adults age >70 years, particularly for acute myelogenous leukemia and myelodysplastic syndromes. Survival rates by disease, disease stage, donor type, and age are presented. This report, prepared annually by the CIBMTR, provides a snapshot of current transplant activity in the United States.

Incidence, Risk Factors, and Outcomes of Patients Who Develop Mucosal Barrier Injury-Laboratory Confirmed Bloodstream Infections in the First 100 Days After Allogeneic Hematopoietic Stem Cell Transplant

IMPORTANCE

Patients undergoing hematopoietic stem cell transplant (HSCT) are at risk for bloodstream infection (BSI) secondary to translocation of bacteria through the injured mucosa, termed mucosal barrier injury-laboratory confirmed bloodstream infection (MBI-LCBI), in addition to BSI secondary to indwelling catheters and infection at other sites (BSI-other).

OBJECTIVE

To determine the incidence, timing, risk factors, and outcomes of patients who develop MBI-LCBI in the first 100 days after HSCT.

DESIGN, SETTING, AND PARTICIPANTS

A case-cohort retrospective analysis was performed using data from the Center for International Blood and Marrow Transplant Research database on 16 875 consecutive pediatric and adult patients receiving a first allogeneic HSCT from January 1, 2009, to December 31, 2016. Patients were classified into 4 categories: MBI-LCBI (1481 [8.8%]), MBI-LCBI and BSI-other (698 [4.1%]), BSI-other only (2928 [17.4%]), and controls with no BSI (11 768 [69.7%]). Statistical analysis was performed from April 5 to July 17, 2018.

MAIN OUTCOMES AND MEASURES

Demographic characteristics and outcomes, including overall survival, chronic graft-vs-host disease, and transplant-related mortality (only for patients with malignant disease), were compared among groups.

RESULTS

Of the 16 875 patients in the study (9737 [57.7%] male; median [range] age, 47 [0.04-82] years) 13 686 (81.1%) underwent HSCT for a malignant neoplasm, and 3189 (18.9%) underwent HSCT for a nonmalignant condition. The cumulative incidence of MBI-LCBI was 13% (99% CI, 12%-13%) by day 100, and the cumulative incidence of BSI-other was 21% (99% CI, 21%-22%) by day 100. Median (range) time from transplant to first MBI-LCBI was 8 (<1 to 98) days vs 29 (<1 to 100) days for BSI-other. Multivariable analysis revealed an increased risk of MBI-LCBI with poor Karnofsky/Lansky performance status (hazard ratio [HR], 1.21 [99% CI, 1.04-1.41]), cord blood grafts (HR, 2.89 [99% CI, 1.97-4.24]), myeloablative conditioning (HR, 1.46 [99% CI, 1.19-1.78]), and posttransplant cyclophosphamide graft-vs-host disease prophylaxis (HR, 1.85 [99% CI, 1.38-2.48]). One-year mortality was significantly higher for patients with MBI-LCBI (HR, 1.81 [99% CI, 1.56-2.12]), BSI-other (HR, 1.81 [99% CI, 1.60-2.06]), and MBI-LCBI plus BSI-other (HR, 2.65 [99% CI, 2.17-3.24]) compared with controls. Infection was more commonly reported as a cause of death for patients with MBI-LCBI (139 of 740 [18.8%]), BSI (251 of 1537 [16.3%]), and MBI-LCBI plus BSI (94 of 435 [21.6%]) than for controls (566 of 4740 [11.9%]).

CONCLUSIONS AND RELEVANCE

In this cohort study, MBI-LCBI, in addition to any BSIs, were associated with significant morbidity and mortality after HSCT. Further investigation into risk reduction should be a clinical and scientific priority in this patient population.

Higher Risks of Toxicity and Incomplete Recovery in 13- to 17-Year-Old Females after Marrow Donation: RDSafe Peds Results

Although donation of bone marrow (BM) or peripheral blood stem cells (PBSCs) from children to family members undergoing allogeneic transplantation are well-established procedures, studies detailing levels of pain, symptoms, and long-term recovery are lacking. To address this lack, we prospectively enrolled 294 donors age <18 years at 25 pediatric transplantation centers in North America, assessing them predonation, peridonation, and at 1 month, 6 months, and 1 year postdonation. We noted that 71% of children reported pain and 59% reported other symptoms peridonation, with resolution to 14% and 12% at 1 month postdonation. Both older age (age 13 to 17 years versus younger) and female sex were associated with higher levels of pain peridonation, with the highest rates in older females (57% with grade 2-4 pain and 17% with grade 3-4 pain). Multivariate analyses showed a 4-fold increase in risk for older females compared with males age <13 years (P <.001). At 1 year, 11% of 13- to 17-year-old females reported grade 2-4 pain, compared with 3% of males age 13 to 17 years, 0% of females age <13 years, and 1% of males age <13 years (P = .01). Males and females age 13 to 17 years failed to return to predonation pain levels at 1 year 22% and 23% of the time, respectively, compared with 3% and 10% in males and females age <13 years (P = .002). Our data show that females age 13 to 17 years are at increased risk of grade 2-4 pain at 1 year and >20% of females and males age 13 to 17 years do not return to baseline pain levels by 1 year after BM donation. Studies aimed at decreasing symptoms and improving recovery in older children are warranted.

Related peripheral blood stem cell donors experience more severe symptoms and less complete recovery at one year compared to unrelated donors

Unlike unrelated donor registries, transplant centers lack uniform approaches to related donor assessment and deferral. To test whether related donors are at increased risk for donation-related toxicities, we conducted a prospective observational trial of 11,942 related and unrelated donors aged 18-60 years. Bone marrow (BM) was collected at 37 transplant and 78 National Marrow Donor Program centers, and peripheral blood stem cells (PBSC) were collected at 42 transplant and 87 unrelated donor centers in North America. Possible presence of medical comorbidities was verified prior to donation, and standardized pain and toxicity measures were assessed pre-donation, peri-donation, and one year following. Multivariate analyses showed similar experiences for BM collection in related and unrelated donors; however, related stem cell donors had increased risk of moderate [odds ratios (ORs) 1.42; P<0.001] and severe (OR 8.91; P<0.001) pain and toxicities (OR 1.84; P<0.001) with collection. Related stem cell donors were at increased risk of persistent toxicities (OR 1.56; P=0.021) and non-recovery from pain (OR 1.42; P=0.001) at one year. Related donors with more significant comorbidities were at especially high risk for grade 2-4 pain (OR 3.43; P<0.001) and non-recovery from toxicities (OR 3.71; P<0.001) at one year. Related donors with more significant comorbidities were at especially high risk for grade 2-4 pain (OR 3.43; P<0.001) and non-recovery from toxicities (OR 3.71; P<0.001) at one year. Related donors reporting grade ≥2 pain had significant decreases in Health-Related Quality of Life (HR-QoL) scores at one month and one year post donation (P=0.004). In conclusion, related PBSC donors with comorbidities are at increased risk for pain, toxicity, and non-recovery at one year after donation. Risk profiles described in this study should be used for donor education, planning studies to improve the related donor experience, and decisions regarding donor deferral. Registered at clinicaltrials.gov identifier:00948636.

Effect of Aging and Predonation Comorbidities on the Related Peripheral Blood Stem Cell Donor Experience: Report from the Related Donor Safety Study

The development of reduced-intensity approaches for allogeneic hematopoietic cell transplantation has resulted in growing numbers of older related donors (RDs) of peripheral blood stem cells (PBSCs). The effects of age on donation efficacy, toxicity, and long-term recovery in RDs are poorly understood. To address this we analyzed hematologic variables, pain, donation-related symptoms, and recovery in 1211 PBSC RDs aged 18 to 79 enrolled in the Related Donor Safety Study. RDs aged > 60 had a lower median CD34+ level before apheresis compared with younger RDs (age > 60, 59 × 106/L; age 41 to 60, 81 × 106/L; age 18 to 40, 121 × 106/L; P < .001). This resulted in older donors undergoing more apheresis procedures (49% versus 30% ≥ 2 collections, P < .001) and higher collection volumes (52% versus 32% > 24 L, P < .001), leading to high percentages of donors aged > 60 with postcollection thrombocytopenia <50 × 109/L (26% and 57% after 2 and 3days of collection, respectively). RDs aged 18 to 40 had a higher risk of grades 2 to 4 pain and symptoms pericollection, but donors over age 40 had more persistent pain at 1, 6, and 12 months (odds ratio [OR], 1.7; P = 0.02) and a higher rate of nonrecovery to predonation levels (OR, 1.7; P = .01). Donors reporting comorbidities increased significantly with age, and those with comorbidities that would have led to deferral by National Marrow Donor Program unrelated donor standards had an increased risk for persistent grades 2 to 4 pain (OR, 2.41; P < .001) and failure to recover to predonation baseline for other symptoms (OR, 2.34; P = .004). This information should be used in counseling RDs regarding risk and can assist in developing practice approaches aimed at improving the RD experience for high-risk individuals.

Characteristics of Late Fatal Infections after Allogeneic Hematopoietic Cell Transplantation

We analyzed late fatal infections (LFIs) in allogeneic stem cell transplantation (HCT) recipients reported to the Center for International Blood and Marrow Transplant Research. We analyzed the incidence, infection types, and risk factors contributing to LFI in 10,336 adult and 5088 pediatric subjects surviving for ≥2 years after first HCT without relapse. Among 2245 adult and 377 pediatric patients who died, infections were a primary or contributory cause of death in 687 (31%) and 110 (29%), respectively. At 12 years post-HCT, the cumulative incidence of LFIs was 6.4% (95% confidence interval [CI], 5.8% to 7.0%) in adults, compared with 1.8% (95% CI, 1.4% to 2.3%) in pediatric subjects; P < .001). In adults, the 2 most significant risks for developing LFI were increasing age (20 to 39, 40 to 54, and ≥55 years versus 18 to 19 years) with hazard ratios (HRs) of 3.12 (95% CI, 1.33 to 7.32), 3.86 (95% CI, 1.66 to 8.95), and 5.49 (95% CI, 2.32 to 12.99) and a history of chronic graft-versus-host disease GVHD (cGVHD) with ongoing immunosuppression at 2 years post-HCT compared with no history of GVHD with (HR, 3.87; 95% CI, 2.59 to 5.78). In pediatric subjects, the 3 most significant risks for developing LFI were a history of cGVHD with ongoing immunosuppression (HR, 9.49; 95% CI, 4.39 to 20.51) or without ongoing immunosuppression (HR, 2.7; 95% CI, 1.05 to 7.43) at 2 years post-HCT compared with no history of GVHD, diagnosis of inherited abnormalities of erythrocyte function compared with diagnosis of acute myelogenous leukemia (HR, 2.30; 95% CI, 1.19 to 4.42), and age >10 years (HR, 1.92; 95% CI, 1.15 to 3.2). This study emphasizes the importance of continued vigilance for late infections after HCT and institution of support strategies aimed at decreasing the risk of cGVHD.

Infection Rates among Acute Leukemia Patients Receiving Alternative Donor Hematopoietic Cell Transplantation

Alternative graft sources (umbilical cord blood [UCB], matched unrelated donors [MUD], or mismatched unrelated donors [MMUD]) enable patients without a matched sibling donor to receive potentially curative hematopoietic cell transplantation (HCT). Retrospective studies demonstrate comparable outcomes among different graft sources. However, the risk and types of infections have not been compared among graft sources. Such information may influence the choice of a particular graft source. We compared the incidence of bacterial, viral, and fungal infections in 1781 adults with acute leukemia who received alternative donor HCT (UCB, n= 568; MUD, n = 930; MMUD, n = 283) between 2008 and 2011. The incidences of bacterial infection at 1 year were 72%, 59%, and 65% (P < .0001) for UCB, MUD, and MMUD, respectively. Incidences of viral infection at 1 year were 68%, 45%, and 53% (P < .0001) for UCB, MUD, and MMUD, respectively. In multivariable analysis, bacterial, fungal, and viral infections were more common after either UCB or MMUD than after MUD (P < .0001). Bacterial and viral but not fungal infections were more common after UCB than MMUD (P = .0009 and <.0001, respectively). The presence of viral infection was not associated with an increased mortality. Overall survival (OS) was comparable among UCB and MMUD patients with Karnofsky performance status (KPS) ≥ 90% but was inferior for UCB for patients with KPS < 90%. Bacterial and fungal infections were associated with poorer OS. Future strategies focusing on infection prevention and treatment are indicated to improve HCT outcomes.

Reduced-Intensity Conditioning with Fludarabine, Cyclophosphamide, and High-Dose Rituximab for Allogeneic Hematopoietic Cell Transplantation for Follicular Lymphoma: A Phase Two Multicenter Trial from the Blood and Marrow Transplant Clinical Trials Network

Allogeneic (allo) hematopoietic cell transplantation (HCT) can induce long-term remissions in chemosensitive relapsed follicular lymphoma (FL). The Blood and Marrow Transplant Clinical Trials Network conducted a multicenter phase 2 trial to examine the efficacy of alloHCT using reduced-intensity conditioning with rituximab (RTX) in multiply relapsed, chemosensitive FL. The primary endpoint was 2-year progression-free survival (PFS). The conditioning regimen consisted of fludarabine, cyclophosphamide, and high-dose RTX (FCR), in which 3 of the 4 doses of RTX were administered at a dose of 1 gm/m(2). Graft-versus-host disease (GVHD) prophylaxis was with tacrolimus and methotrexate. Sixty-five patients were enrolled and 62 were evaluable. Median age was 55 years (range, 29 to 74). This group was heavily pretreated: 77% had received ≥ 3 prior regimens, 32% had received ≥ 5 prior regimens, and 11% had received prior autologous HCT. Donors were HLA-matched siblings (n = 33) or HLA-matched unrelated adults (n = 29). No graft failures occurred. The overall response rate after HCT was 94% with 90% in complete remission (CR), including 24 patients not in CR before alloHCT. With a median follow-up of 47 months (range, 30 to 73), 3-year PFS and overall survival rates were 71% (95% confidence interval, 58% to 81%) and 82% (95% confidence interval, 70% to 90%), respectively. Three-year cumulative incidences of relapse/progression and nonrelapse mortality were 13% and 16%, respectively. Two-year cumulative incidences of grades 2 to 4 and grades 3 or 4 acute GVHD were 27% and 10%, respectively, and extensive chronic GVHD incidence was 55%. Serum RTX concentrations peaked at day +28 and remained detectable as late as 1 year in 59% of patients with available data. In conclusion, alloHCT with FCR conditioning confers high CR rates, a low incidence of relapse/progression, and excellent survival probabilities in heavily pretreated FL patients.

Phase 3 trial of defibrotide for the treatment of severe veno-occlusive disease and multi-organ failure

Hepatic veno-occlusive disease (VOD), also called sinusoidal obstruction syndrome (SOS), is a potentially life-threatening complication of hematopoietic stem cell transplantation (HSCT). Untreated hepatic VOD/SOS with multi-organ failure (MOF) is associated with >80% mortality. Defibrotide has shown promising efficacy treating hepatic VOD/SOS with MOF in phase 2 studies. This phase 3 study investigated safety and efficacy of defibrotide in patients with established hepatic VOD/SOS and advanced MOF. Patients (n = 102) given defibrotide 25 mg/kg per day were compared with 32 historical controls identified out of 6867 medical charts of HSCT patients by blinded independent reviewers. Baseline characteristics between groups were well balanced. The primary endpoint was survival at day +100 post-HSCT; observed rates equaled 38.2% in the defibrotide group and 25% in the controls (23% estimated difference; 95.1% confidence interval [CI], 5.2-40.8;P= .0109, using a propensity-adjusted analysis). Observed day +100 complete response (CR) rates equaled 25.5% for defibrotide and 12.5% for controls (19% difference using similar methodology; 95.1% CI, 3.5-34.6;P= .0160). Defibrotide was generally well tolerated with manageable toxicity. Related adverse events (AEs) included hemorrhage or hypotension; incidence of common hemorrhagic AEs (including pulmonary alveolar [11.8% and 15.6%] and gastrointestinal bleeding [7.8% and 9.4%]) was similar between the defibrotide and control groups, respectively. Defibrotide was associated with significant improvement in day +100 survival and CR rate. The historical-control methodology offers a novel, meaningful approach for phase 3 evaluation of orphan diseases associated with high mortality. This trial was registered at www.clinicaltrials.gov as #.

Risk factors and impact of non-Aspergillus mold infections following allogeneic HCT: a CIBMTR infection and immune reconstitution analysis

Risk factors for non-Aspergillus mold infection (NAMI) and the impact on transplant outcome are poorly assessed in the current era of antifungal agents. Outcomes of 124 patients receiving allogeneic HCT diagnosed with either mucormycosis [n=72] or fusariosis [n=52] between days 0-365 after HCT are described and compared to a control cohort (n=11856). Patients with NAMI had more advanced disease [mucormycois 25%, fusariosis 23%, controls 18%; p = 0.004] and were more likely to have a KPS<90% at HCT [mucormycosis 42%, fusariosis 38%, controls 28%; p=0.048]. The 1-year survival after HCT was 22% (15–29%) for cases and was significantly inferior compared to controls [65%(64–65%); p < 0.001]. Survival from infection was similarly dismal regardless of mucormycosis [15% (8-25%)] and fusariosis [21% (11-33%)].

In multivariable analysis, NAMI was associated with a 6-fold higher risk of death (p<0.0001) regardless of the site or timing of infection. Risk factors for mucormycosis include preceding acute GVHD, prior aspergillus infection, and older age. For fusariosis, increased risks including receipt of cord blood, prior CMV infection, and transplant prior to May 2002. In conclusion, NAMI occurs infrequently, is associated with high mortality, and appears with similar frequency in the current antifungal era.