Blood and marrow transplant clinical trials network state of the Science Symposium 2014

Phase 2 study of natalizumab plus standard corticosteroid treatment for high-risk acute graft-versus-host disease

Graft-versus-host disease (GVHD) of the gastrointestinal (GI) tract is the main cause of nonrelapse mortality (NRM) after allogeneic hematopoietic cell transplantation. Ann Arbor (AA) scores derived from serum biomarkers at onset of GVHD quantify GI crypt damage; AA2/3 scores correlate with resistance to treatment and higher NRM. We conducted a multicenter, phase 2 study using natalizumab, a humanized monoclonal antibody that blocks T-cell trafficking to the GI tract through the α4 subunit of α4β7 integrin, combined with corticosteroids as primary treatment for patients with new onset AA2/3 GVHD. Seventy-five patients who were evaluable were enrolled and treated; 81% received natalizumab within 2 days of starting corticosteroids. Therapy was well tolerated with no treatment emergent adverse events in >10% of patients. Outcomes for patients treated with natalizumab plus corticosteroids were compared with 150 well-matched controls from the MAGIC database whose primary treatment was corticosteroids alone. There were no significant differences in overall or complete response between patients treated with natalizumab plus corticosteroids and those treated with corticosteroids alone (60% vs 58%; P = .67% and 48% vs 48%; P = 1.0, respectively) including relevant subgroups. There were also no significant differences in NRM or overall survival at 12 months in patients treated with natalizumab plus corticosteroids compared with controls treated with corticosteroids alone (38% vs 39%; P = .80% and 46% vs 54%; P = .48, respectively). In this multicenter biomarker-based phase 2 study, natalizumab combined with corticosteroids failed to improve outcome of patients with newly diagnosed high-risk GVHD. This trial was registered at www.clinicaltrials.gov as # NCT02133924.

Blood and Marrow Transplant Clinical Trials Network State of the Science Symposium 2021: Looking Forward as the Network Celebrates its 20th Year

In 2021 the BMT CTN held the 4th State of the Science Symposium where the deliberations of 11 committees concerning major topics pertinent to a particular disease, modality, or complication of transplant, as well as two committees to consider clinical trial design and inclusion, diversity, and access as cross-cutting themes were reviewed. This article summarizes the individual committee reports and their recommendations on the highest priority questions in hematopoietic stem cell transplant and cell therapy to address in multicenter trials.

The role of biomarkers in risk stratification, treatment and outcome in acute GVHD

PURPOSE OF REVIEW

Graft-versus-host disease (GVHD) following hematopoietic cell transplant (HCT) has a significant impact on morbidity and mortality among recipients. Predicting the long-term outcomes at the time of diagnosis of GVHD or even after response to up-front therapy can be challenging and only has modest accuracy. With biomarkers available to help guide decision-making, the landscape of GVHD is evolving.

RECENT FINDINGS

Several acute GVHD biomarkers have been identified, with some better able to categorize patients based on their GVHD severity and potential for refractory disease than standard clinical staging or response criteria.

SUMMARY

Biomarkers are now being incorporated into the clinical trial design for both high and low-risk GVHD. These findings will likely impact how clinical care is delivered in the future as improved risk stratification has the potential to improve outcomes by providing individualized treatment plans for affected patients.

Hematopoietic Cell Transplantation: Practice Predictions for the Year 2023

Research priorities are best determined by the most pressing scientific questions, in the context of current knowledge. However, definitive research studies take time, while real-world experience accumulates. Adoption of new practices before adequate comparison with current treatments threatens successful study conduct and may expose patients to what ultimately turns out to be inferior treatment. We conducted a survey to understand the hematopoietic cell transplantation (HCT) community's predictions about future practice trends in the HCT field and results of ongoing Blood and Marrow Transplant Clinical Trials Network (BMT CTN) trials to gauge how the HCT community views the treatments being studied. The survey was distributed between February and March 2019 to an electronic mailing list of HCT clinicians practicing in the United States maintained by the Center for International Blood and Marrow Transplant Research (CIBMTR). Of 986 clinicians surveyed, 315 responded (32%). They predicted an increase in the number of HCTs performed for malignant hematologic diseases and benign diseases such as sickle cell, autoimmune, and genetic disorders. The majority (63%) predicted that matched related donors will remain the preferred donor source for adult HCT recipients in 2023, but 21% predicted haploidentical (haplo) donors and 17% predicted matched unrelated donors would be the preferred source. Most respondents (65%) predicted a decrease in the use of umbilical cord blood (UCB) as a graft source for HCT. Most respondents also predicted that calcineurin-based graft-versus-host disease (GVHD) prophylaxis would be replaced by post-transplantation cyclophosphamide (PTCy) (55%), biomarker use would become standard practice to guide GVHD therapy (73%), and steroids would be combined with other agents as first-line therapy for newly diagnosed acute (53%) and chronic GVHD (54%). In ongoing BMT CTN trials in which outcomes are not yet known, 60% to 92% of respondents had an opinion about which arm they thought would be superior. However, not all respondents predicted the same outcome, with 44% to 88% choosing the same arm. There was no clear relationship between the proportion predicting the same arm would win and accrual to the trial. Survey respondents were optimistic about an increasing volume of transplantation procedures, and they also expected significant changes in HCT practice over the next few years, including wider adoption of PTCy GVHD prophylaxis, increased use of biomarkers to guide GVHD therapy, and decreased use of UCB HCT. The degree of equipoise in the community about the relative efficacy of therapies being studied did not seem to affect accrual to current BMT CTN trials, but this is an area that needs further investigation.

Hematopoietic Stem Cell Transplantation, Where Have We Come and Where Do We Go

Hematopoietic cellular transplantation (HCT) has impacted medicine beyond simply treating certain diseases. Allogeneic HCT was the first documented successful immunological cellular therapy. Its usage continues to increase. The immunological disparity between donor and recipient has been associated with better antitumor efficacy as well as immunological toxicities. Through active clinical trials and research, considerable improvements in HCT therapy have been made over the past 50 years. The HCT international outcomes registry has considerably contributed to these improvements by identifying factors that could never be studied by a single center. With the use of unrelated donors, international collaboration increased as donor cell access through registries was not inhibited by international boundaries. HCT as a field pioneered the development of organizations for self-regulation that were assessing the entire program as an integrated whole rather than simply assessing facilities and providers separately.

Randomized multicenter trial of sirolimus vs prednisone as initial therapy for standard-risk acute GVHD: the BMT CTN 1501 trial

Clinical- and biomarker-based tools may identify a lower-risk acute graft-versus-host disease (GVHD) population amenable to novel, reduced-intensity treatments. Previous data suggest sirolimus may rival standard of care prednisone. We conducted a National Heart, Lung, and Blood Institute/National Cancer Institute-funded Blood and Marrow Transplant Clinical Trials Network multicenter, open-label, randomized phase 2 trial to estimate the difference in day 28 complete response (CR)/partial response (PR) rates for sirolimus vs prednisone as initial treatment of patients with standard risk (SR) acute GVHD as defined by the Minnesota (MN) GVHD Risk Score and Ann Arbor (AA1/2) biomarker status. A total of 127 MN-SR patients were randomized (1:1), and 122 were AA1/2 (sirolimus, n = 58; prednisone, n = 64). Others were AA3 (n = 4), or AA status missing (n = 1). The day 28 CR/PR rates were similar for sirolimus 64.8% (90% confidence interval [CI], 54.1%-75.5%) vs 73% (90% CI, 63.8%-82.2%) for prednisone. The day 28 rate of CR/PR with prednisone ≤0.25 mg/kg/day was significantly higher for sirolimus than prednisone (66.7% vs 31.7%; P < .001). No differences were detected in steroid-refractory acute GVHD, disease-free survival, relapse, nonrelapse mortality, or overall survival. Sirolimus was associated with reduced steroid exposure and hyperglycemia, reduced grade 2 to 3 infections, improvement in immune suppression discontinuation and patient-reported quality of life, and increased risk for thrombotic microangiopathy. For patients with clinical- and biomarker-based SR acute GVHD, sirolimus demonstrates similar overall initial treatment efficacy as prednisone. In addition, sirolimus therapy spares steroid exposure and allied toxicity, does not compromise long-term survival outcomes, and is associated with improved patient-reported quality of life. This trial was registered at www.clinicaltrials.gov as #NCT02806947.

Graft Versus Host Disease Clinical Trials: Is it Time for Patients Centered Outcomes to Be the Primary Objective?

PURPOSE OF REVIEW

Graft versus host disease (GVHD) is a common complication following hematopoietic cell transplant and is associated with a high symptom burden, reduced functional status, and impaired quality of life (QOL). QOL is best assessed by patient-reported outcomes (PRO). Numerous clinical trials for the prevention and treatment of GVHD are available. This review aims to understand the landscape of PRO inclusion in clinical trials for GVHD over the last decade.

RECENT FINDINGS

Consensus bodies, including experts in GVHD, PRO, and clinical trials have made recommendations for a standardized approach for the inclusion of PRO in clinical trials including as primary outcomes, however, these have yet to be implemented in a consistent manner in practice. Consistently applying consensus recommendation in chronic GVHD will ensure that PROs are appropriately included in clinical trials. Development of validated measures in acute GVHD and composite outcomes for all GVHD trials are required.

Priorities for Improving Outcomes for Nonmalignant Blood Diseases: A Report from the Blood and Marrow Transplant Clinical Trials Network

Nonmalignant blood diseases such as bone marrow failure disorders, immune dysregulation disorders, and hemoglobinopathies often lead to shortened life spans and poor quality of life. Many of these diseases can be cured with allogeneic hematopoietic cell transplantation, but patients are often not offered the procedure because of perceived insufficient efficacy and/or excess toxicity. In 2018, the Blood and Marrow Transplant Clinical Trials Network convened a task force to identify the most urgently needed yet feasible clinical trials with potential to improve the outcomes for patients with nonmalignant diseases. This report summarizes the task force discussions and specifies the network plans for clinical trial development for nonmalignant blood diseases.

Patient HLA Germline Variation and Transplant Survivorship

Purpose HLA mismatching increases mortality after unrelated donor hematopoietic cell transplantation. The role of the patient's germline variation on survival is not known. Patients and Methods We previously identified 12 single nucleotide polymorphisms within the HLA region as markers of transplantation determinants and tested these in an independent cohort of 1,555 HLA-mismatched unrelated transplants. Linkage disequilibrium mapping across class II identified candidate susceptibility features. The candidate gene was confirmed in an independent cohort of 3,061 patients. Results Patient rs429916AA/AC was associated with increased transplantation-related mortality compared with rs429916CC (hazard ratio [HR], 1.39; 95% CI, 1.12 to 1.73; P = .003); rs429916A positivity was a proxy for DOA*01:01:05. Mortality increased with one (HR, 1.17; 95% CI, 1.0 to 1.36; P = .05) and two (HR, 2.51; 95% CI, 1.41 to 4.45; P = .002) DOA*01:01:05 alleles. HLA-DOA*01:01:05 was a proxy for HLA-DRB1 alleles encoding FEY ( P < 10E^-15) and FDH ( P < 10E^-15) amino acid substitutions at residues 26/28/30 that influence HLA-DRβ peptide repertoire. FEY- and FDH-positive alleles were positively associated with rs429916A ( P < 10E^-15); FDY-positive alleles were negatively associated. Mortality was increased with FEY (HR, 1.66; 95% CI, 1.29 to 2.13; P = .00008) and FDH (HR, 1.40; 95% CI, 1.02 to 1.93; P = .04), whereas FDY was protective (HR, 0.88; 95% CI, 0.78 to 0.98; P = .02). Of the three candidate motifs, FEY was validated as the susceptibility determinant for mortality (HR, 1.29; 95% CI, 1.00 to 1.67; P = .05). Although FEY was found frequently among African and Hispanic Americans, it increased mortality independently of ancestry. Conclusion Patient germline HLA-DRB1 alleles that encode amino acid substitutions that influence the peptide repertoire of HLA-DRβ predispose to increased death after transplantation. Patient germline variation informs transplantation outcomes across US populations and may provide a means to reduce risks for high-risk patients through pretransplantation screening and evaluation.

The Blood and Marrow Transplant Clinical Trials Network: An Effective Infrastructure for Addressing Important Issues in Hematopoietic Cell Transplantation

Hematopoietic cell transplantation (HCT) is a rapidly evolving field with active preclinical and clinical development of new strategies for patient assessment, graft selection and manipulation, and pre- and post-transplantation drug and cell therapy. New strategies require evaluation in definitive clinical trials; however, HCT trials face unique challenges, including the relatively small number of transplantations performed at any single center, the diverse indications for HCT requiring dissimilar approaches, the complex nature of the intervention itself, the risk of multiple complications in the immediate post-transplantation period, and the risk of important, though infrequent, late effects. The Blood and Marrow Transplant Clinical Trials Network (BMT CTN) was established by the US National Heart Lung and Blood Institute and the National Cancer Institute to meet these challenges. In its 15 years as a network, the BMT CTN has proven to be a successful infrastructure for planning, implementing, and completing such trials and for providing definitive answers to questions leading to improvements in the understanding and practice of HCT. It has opened 37 trials, about one-half phase 2 and one-half phase 3, enrolled more than 8000 patients, and published 57 papers addressing important issues in the treatment of patients with life-threatening malignant and nonmalignant blood disorders. This review describes the network's accomplishments, key components of its success, lessons learned over the past 15 years, and challenges for the future.

Practice Patterns and Preferences Among Hematopoietic Cell Transplantation Clinicians

Hematopoietic cell transplantation can cure many high-risk diseases but is associated with complexity, cost, and risk. Several areas in transplantation practice were identified in the 2014 Blood and Marrow Transplant Clinical Trials Network State of the Science Symposium (BMT CTN SOSS) as high priorities for further study. We developed a survey for hematopoietic cell transplantation clinicians to identify current practices in BMT CTN SOSS priority areas and to understand, more generally, the variation in approach to transplantation and estimation of transplantation benefit in current medical practice. Of 1439 transplantation clinicians surveyed, 305 responded (20% response rate). Clinicians were well represented by age, experience, geography, and size of practice. We found that several techniques identified in the BMT CTN SOSS, such as maintenance therapy for acute myeloid leukemia or myelodysplastic syndromes after allogeneic transplantation, were already being utilized in practice on and off study, with higher rates of use in higher-volume centers. There was significant variation among clinicians in use of transplantation technologies and approaches to common transplantation scenarios. Appraisals of risks and benefits of transplantation appeared to converge upon similar estimates despite the presentation of different hypothetical scenarios. These results suggest overall equipoise in several BMT CTN SOSS high-priority areas and support the need for better data to inform clinical practice.

Up-to-date tools for risk assessment before allogeneic hematopoietic cell transplantation

Cure of malignant and non-malignant hematological diseases is potentially possible after allogeneic hematopoietic stem cell transplantation (HCT). Accurate evaluation of the risk-benefit ratio for an individual patient could improve the decision-making process about transplant, which ultimately would increase the likelihood of success. Several transplant-related models were designed in an effort to optimize decision-making about suitable candidates for allogeneic HCT. In 1998, The European Society for Blood and Marrow Transplantation (EBMT) developed a five-component pretransplantation risk scoring system for patients with CML. The EBMT score was later tested in patients with various hematological disorders, and it was shown to stratify risks of mortality after allogeneic HCT. More recent research efforts focused on models that assess health status before HCT. A HCT-specific comorbidity index was designed to assign weights to 17 relevant comorbidities that were shown to independently predict non-relapse mortality. Performance status scales and comprehensive geriatric assessment tools might uncover additional overall health limitations that affect long-term survival among older recipients of allogeneic HCT. Other models include the pretransplantation assessment of mortality score that summarizes the impacts of eight different pretransplantation patient- and disease-specific variables into a 50-point model that predicts survival. The disease-risk index captures the impact of primary diagnoses and disease status on relapse and survival following allogeneic HCT. The values and limitations of each model are discussed herein. We also provide insight on how to use these models in the clinic to decide about offering allogeneic HCT with the most suitable conditioning regimen intensity.

Prospective Validation of the Predictive Power of the Hematopoietic Cell Transplantation Comorbidity Index: A Center for International Blood and Marrow Transplant Research Study

Prospective validation of the hematopoietic cell transplantation-comorbidity index (HCT-CI) using contemporary patients treated with hematopoietic cell transplantation (HCT) across the Unites States is necessary to confirm its widespread applicability. We performed a prospective observational study including all patients (8115 recipients of allogeneic and 11,652 recipients of autologous HCT) who underwent a first HCT that was reported to the Center for International Blood and Marrow Transplant Research between 2007 and 2009. In proportional hazards models, increased HCT-CI scores were independently associated with increases in hazard ratios for nonrelapse mortality (NRM) (P < .0001) and overall mortality (P < .0001) among recipients of allogeneic HCT. HCT-CI scores of ≥3 were uniformly associated with higher risks for outcomes in both allogeneic and autologous HCT and in all subgroups, regardless of diagnoses, age, and conditioning intensity. Recipients of allogeneic HCT with scores of 1 and 2 who were ages < 18 years or were treated with lower intensity conditioning regimens had similar outcomes compared with those with a score of 0. Higher risks for overall mortality, but not for NRM, were observed among recipients of autologous HCT with scores of 1 and 2 versus 0. Our results confirm the validity the HCT-CI in both allogeneic and autologous HCT. The index should be used as a valid standard-of-care health measure in counseling patients for HCT, in clinical trial design, and in adjusting outcome analyses.

Alternative Donor Transplantation for Acute Myeloid Leukemia

Allogeneic hematopoietic cell transplantation (allo-HCT) is a potentially curative therapy for adult patients with acute myeloid leukemia (AML), but its use for consolidation therapy after first remission with induction chemotherapy used to be limited to younger patients and those with suitable donors. The median age of AML diagnosis is in the late 60s. With the introduction of reduced-intensity conditioning (RIC), many older adults are now eligible to receive allo-HCT, including those who are medically less fit to receive myeloablative conditioning. Furthermore, AML patients commonly have no human leukocyte antigen (HLA)-identical or medically suitable sibling donor available to proceed with allo-HCT. Technical advances in donor matching, suppression of alloreactivity, and supportive care have made it possible to use alternative donors, such as unrelated umbilical cord blood (UCB) and partially HLA-matched related (haploidentical) donors. Outcomes after alternative donor allo-HCT are now approaching the outcomes observed for conventional allo-HCT with matched related and unrelated donors. Thus, with both UCB and haploidentical donors available, lack of donor should rarely be a limiting factor in offering an allo-HCT to adults with AML.