Long-term Outcomes of Peripheral Blood Stem Cell Unrelated Donors Mobilized with Filgrastim.

Allogeneic hematopoietic cell transplantation is a life-saving procedure used to treat of a variety of devastating diseases. It requires hematopoietic stem cells collected via filgrastim mobilized peripheral blood stem cells or bone marrow harvest from volunteer unrelated donors. There is a paucity of safety data regarding donors' long-term adverse events. This prospective, observational study combined peripheral blood stem cell donors enrolled on the NMDP Investigational New Drug trial and bone marrow donors between July 1, 1999, and September 30, 2015. The primary objective was to describe the long-term incidence of myeloid malignancies. Secondary objectives included describing the long-term incidence of lymphoid malignancies, non-hematologic malignancies, autoimmune disorders, and thrombotic events. 21643 donors (14530 peripheral blood stem cells and 7123 bone marrow) were included. The incidence rate of myeloid disorders per 100000 person years in donors of peripheral blood stem cells was 2.53 (95% CI: 0.82-7.84) and in donors of bone marrow it was 4.13 (95% CI: 1.33-12.8). The incidence rate ratio of peripheral blood stem cells /bone marrow donors was 0.61 (95% CI: 0.12-3.03; p=0.55). The incidence of other malignancies, autoimmunity, and thrombosis did not differ between donor types. This comprehensive study of long-term effects of filgrastim in unrelated donors of peripheral blood stem cells provides strong evidence that donors who receive filgrastim are not at increased risk of these events compared to bone marrow donors. It also provides reassurance to current donors undergoing stem cell mobilization as well as individuals considering joining stem cell registries such as NMDP.

Clinical Outcomes and Treatment Patterns in Adults With FLT3-ITDmut+ Acute Myeloid Leukemia Undergoing Allogeneic Hemopoietic Cell Transplantation in the US and Canada.

Allogeneic hematopoietic cell transplantation (alloHCT) is used to treat patients with acute myeloid leukemia (AML) with internal tandem duplication of the FMS-like tyrosine kinase 3 gene (FLT3-ITDmut+). However, the effect of different characteristics on outcomes after transplant is not fully understood. To determine the impact of patient, disease, and transplant characteristics on clinical outcomes and trends in maintenance therapy for patients with FLT3-ITDmut+ AML who underwent their first alloHCT. This was an observational cohort study of adults ≥18 years who were recipients of human leukocyte antigen identical sibling, haploidentical, 8/8 or 7/8 unrelated, or cord blood donor alloHCT in the United States and Canada between 2014 and 2019. Patient, disease, and transplant characteristics were collected from Center for International Blood and Marrow Transplant Research between 2014 and 2022. Patients enrolled in the MORPHO clinical trial (NCT02997202) were excluded. Clinical outcomes were measured from the time of alloHCT by disease status: first complete remission (CR1), second or greater complete remission (≥CR2), or relapsed/refractory (R/R). The primary endpoints of this study were overall survival (OS) and leukemia-free survival (LFS). Key secondary endpoints included relapse after alloHCT, nonrelapse mortality (NRM), time from diagnosis to complete remission, time from complete remission to alloHCT, and maintenance therapy before and after alloHCT. Univariate analyses were conducted with Gray's test and log-rank test, while multivariable analyses were conducted using Cox proportional hazards models. A total of 3147 eligible patients (CR1, n = 2389; ≥CR2, n = 340; R/R, n = 418) were included. Most patient, disease, and transplant characteristics were similar between different disease statuses. In univariate analyses, disease status of CR1 compared with ≥CR2 or R/R was significantly (P < .001) associated with improved OS and LFS, and decreased probability of relapse; NRM likely differed across cohorts after alloHCT (P = .003). In multivariable analyses, patients with a disease status of ≥CR2 and R/R compared with CR1 had significantly shorter OS (hazard ratio [HR] 95% confidence interval [CI], 1.43 [1.19 to 1.72], P = .0001, and 2.14 [1.88 to 2.44], P < .0001, respectively). Patients with a disease status of CR1 at ≤2.6 months had better LFS compared with ≥CR2 and R/R (HR [95% CI], 2.03 [1.56 to 2.63], P < .0001 and 3.98 [3.07 to 5.17], P < .0001, respectively). Patients with a ≥CR2 or R/R disease status at ≤2.6 months had an increased likelihood of relapse compared with CR1 (HR [95% CI], 2.46 [1.82 to 3.33], P < .0001 and 4.68 [3.46 to 6.34], P < .0001, respectively). Disease status was not significantly associated with NRM. We also identified several additional patient, disease, and transplant characteristics that may be associated with inferior OS and/or LFS and greater relapse and/or NRM. Maintenance therapy usage after alloHCT increased from 2014 to 2019 primarily due to increased FLT3 inhibitor use. In this largest study to date of patients from the United States and Canada with FLT3-ITDmut+ AML, disease status of CR1 at the time of alloHCT was associated with better clinical outcomes. Additional factors were identified that may also impact clinical outcomes, and in total, have the potential to inform clinical decision-making.

A phase 2 trial of CD24Fc for prevention of graft-versus-host disease.

ABSTRACT: Patients who undergo human leukocyte antigen-matched unrelated donor (MUD) allogeneic hematopoietic stem cell transplantation (HSCT) with myeloablative conditioning for hematologic malignancies often develop acute graft-versus-host disease (GVHD) despite standard calcineurin inhibitor-based prophylaxis in combination with methotrexate. This trial evaluated a novel human CD24 fusion protein (CD24Fc/MK-7110) that selectively targets and mitigates inflammation due to damage-associated molecular patterns underlying acute GVHD while preserving protective immunity after myeloablative conditioning. This phase 2a, multicenter study evaluated the pharmacokinetics, safety, and efficacy of CD24Fc in combination with tacrolimus and methotrexate in preventing acute GVHD in adults undergoing MUD HSCT for hematologic malignancies. A double-blind, placebo-controlled, dose-escalation phase to identify a recommended dose was followed by an open-label expansion phase with matched controls to further evaluate the efficacy and safety of CD24Fc in preventing acute GVHD. A multidose regimen of CD24Fc produced sustained drug exposure with similar safety outcomes when compared with single-dose regimens. Grade 3 to 4 acute GVHD-free survival at day 180 was 96.2% (95% confidence interval [CI], 75.7-99.4) in the CD24Fc expansion cohort (CD24Fc multidose), compared with 73.6% (95% CI, 63.2-81.4) in matched controls (hazard ratio, 0.1 [95% CI, 0.0-0.6]; log-rank test, P = .03). No participants in the CD24Fc escalation or expansion phases experienced dose-limiting toxicities (DLTs). The multidose regimen of CD24Fc was well tolerated with no DLTs and was associated with high rates of severe acute GVHD-free survival after myeloablative MUD HSCT. This trial was registered at ClinicalTrials.gov as #NCT02663622.

Improved outcomes of UM171-expanded cord blood transplantation compared with other graft sources: real-world evidence.

Cord blood (CB) transplantation is hampered by low cell dose and high nonrelapse mortality (NRM). A phase 1-2 trial of UM171-expanded CB transplants demonstrated safety and favorable preliminary efficacy. The aim of the current analysis was to retrospectively compare results of the phase 1-2 trial with those after unmanipulated CB and matched-unrelated donor (MUD) transplants. Data from recipients of CB and MUD transplants were obtained from the Center for International Blood and Marrow Transplant Research (CIBMTR) database. Patients were directly matched for the number of previous allogeneic hematopoietic stem cell transplants (alloHCT), disease and refined Disease Risk Index. Patients were further matched by propensity score for age, comorbidity index, and performance status. Primary end points included NRM, progression-free survival (PFS), overall survival (OS), and graft-versus-host disease (GVHD)-free relapse-free survival (GRFS) at 1 and 2 years after alloHCT. Overall, 137 patients from CIBMTR (67 CB, 70 MUD) and 22 with UM171-expanded CB were included. NRM at 1 and 2 years was lower, PFS and GRFS at 2 years and OS at 1 year were improved for UM171-expanded CBs compared with CB controls. Compared with MUD controls, UM171 recipients had lower 1- and 2-year NRM, higher 2-year PFS, and higher 1- and 2-year GRFS. Furthermore, UM171-expanded CB recipients experienced less grades 3-4 acute GVHD and chronic GVHD compared with MUD graft recipients. Compared with real-world evidence with CB and MUD alloHCT, this study suggests that UM171-expanded CB recipients may benefit from lower NRM and higher GRFS. This trial was registered at www.clinicaltrials.gov as #NCT02668315.

How do we improve the translation of new evidence into the practice of hematopoietic cell transplantation and cellular therapy?

The field of hematopoietic cell transplantation and cell therapy (HCT/CT) is advancing rapidly to bring an ever-expanding collection of potentially curative therapies to patients with malignant and non-malignant diseases. The impact of these therapies depends on our ability to implement them as new evidence becomes available to advance the quality of care. There is often a long delay between evidence development and adoption of therapies based on that evidence into clinical practice. In this review, we describe the potential factors based on an implementation framework that could act as facilitators or barriers to adoption of therapies in the context of HCT/CT. We highlight two examples, the first to showcase the efforts to improve the efficiency of adoption of new findings and accelerate improvement in care of HCT/CT patients and the second to discuss the challenges in real world implementation of chimeric antigen receptor T cell therapy. We conclude by reviewing strategies to improve translation of evidence and ways to measure their success.

What do patients think about palliative care? A national survey of hematopoietic stem cell transplant recipients.

Palliative care (PC) benefits patients undergoing hematopoietic stem cell transplantation (HSCT), but it remains underutilized. Although transplant physicians report concerns regarding how patients perceive PC, HSCT recipients' perceptions about PC remain unaddressed. We conducted a multisite, cross-sectional survey of autologous and allogeneic HSCT recipients 3 to 12 months after transplant to assess their familiarity, knowledge, and perception of PC, as well as their unmet PC needs. We computed a composite score of patients' perceptions of PC and used a generalized linear regression model to examine factors associated with these perceptions. We enrolled 69.6% (250/359) of potential participants (median age = 58.1; 63.1% autologous HSCT). Overall, 44.3.8% (109/249) reported limited knowledge about PC and 52% (127/245) endorsed familiarity with PC. Most patients felt hopeful (54%) and reassured (50%) when they heard the term PC; 83% saw referral as a sign their doctor cared about what was happening to them. In multivariate analyses, patients who were more knowledgeable about PC were more likely to have positive perceptions of PC (B = 7.54, standard error = 1.61, P < .001). Patients' demographics, HSCT features, quality of life, and symptom burden were not significantly associated with perceptions of PC. HSCT recipients have positive perceptions of PC, though many have limited knowledge about its role. Patients who were more knowledgeable about PC were more likely to have positive perceptions of PC. These data do not support transplant physicians' negative concerns about how patients perceive PC and underscore the need to further educate patients and transplant physicians about PC.

Three-Year Outcomes in Recipients of Mismatched Unrelated Bone Marrow Donor Transplants Using Post-Transplantation Cyclophosphamide: Follow-Up from a National Marrow Donor Program-Sponsored Prospective Clinical Trial.

The use of post-transplantation cyclophosphamide (PTCy) as graft-versus-host disease (GVHD) prophylaxis has resulted in reductions in GVHD and improved outcomes in allogeneic hematopoietic cell transplantation (HCT) using HLA-mismatched related donors. We report the 3-year outcomes of the first multicenter prospective clinical trial using PTCy in the setting of mismatched unrelated donor (MMUD) bone marrow HCT. The study enrolled 80 patients, treated with either myeloablative conditioning (MAC; n = 40) or reduced-intensity conditioning (RIC; n = 40), with the primary endpoint of 1-year overall survival (OS). The median follow-up for this study was 34 months (range, 12 to 46 months) in the RIC group and 36 months (range, 18 to 49 months) in the MAC group. Three-year OS and nonrelapse mortality were 70% and 15%, respectively, in the RIC group and 62% and 10% in the MAC group. No GVHD was reported after 1 year. The incidence of relapse was 29% in the RIC group and 51% in the MAC group. OS did not differ based on HLA match grade (63% in the 7/8 strata and 71% in the 4 to 6/8 strata). These encouraging outcomes, which were sustained for 3 years post-HCT, support the continued exploration of MMUD HCT using a PTCy platform. Important future areas to address include relapse reduction and furthering our understanding of optimal donor selection based on HLA and non-HLA factors.

Male-specific late effects in adult hematopoietic cell transplantation recipients: a systematic review from the Late Effects and Quality of Life Working Committee of the Center for International Blood and Marrow Transplant Research and Transplant Complications Working Party of the European Society of Blood and Marrow Transplantation.

Male-specific late effects after hematopoietic cell transplantation (HCT) include genital chronic graft-versus-host disease (GvHD), hypogonadism, sexual dysfunction, infertility, and subsequent malignancies. They may be closely intertwined and cause prolonged morbidity and decreased quality of life after HCT. We provide a systematic review of male-specific late effects in a collaboration between transplant physicians, endocrinologists, urologists, dermatologists, and sexual health professionals through the Late Effects and Quality of Life Working Committee of the Center for International Blood and Marrow Transplant Research, and the Transplant Complications Working Party of the European Society of Blood and Marrow Transplantation. The systematic review summarizes incidence, risk factors, screening, prevention and treatment of these complications and provides consensus evidence-based recommendations for clinical practice and future research.

Are We Making PROGRESS in Preventing Graft-versus-Host Disease and Improving Clinical Outcomes? Impact of BMT CTN 1301 Study Results on Clinical Practice.

The need for prospective randomized clinical trials investigating novel graft-versus-host disease (GVHD) prevention strategies that include other clinical outcomes impacted by GVHD has been highlighted as a priority for the field of hematopoietic cell transplantation. A recently completed study through the Blood and Marrow Transplant Clinical Trials Network (BMT CTN 1301) comparing CD34+ selection and post-transplantation cyclophosphamide with tacrolimus/methotrexate (Tac/MTX) for GVHD prevention demonstrated no significant differences in the primary endpoint of chronic GVHD relapse-free survival among the 3 approaches. The trial did not demonstrate a superior approach compared with Tac/MTX; however, it did highlight several challenges in determining the best and most relevant approaches to clinical trial design, particularly in the context of current and ongoing changes in real-world practices. Here we review the results of BMT CTN 1301 and their implications for clinical practice and future clinical trial design.

Updated Trends in Hematopoietic Cell Transplantation in the United States with an Additional Focus on Adolescent and Young Adult Transplantation Activity and Outcomes.

Hematopoietic cell transplantation (HCT) has been successfully used to treat many malignant and nonmalignant conditions. As supportive care, donor selection, and treatment modalities evolve, documenting HCT trends and outcomes is critical. This report from the Center for International Blood and Marrow Transplant Research (CIBMTR) provides an update on current transplantation activity and survival rates in the United States. Additional data on the use and outcomes of HCT in the adolescent and young adult (AYA) population are included. AYA patients more frequently receive peripheral blood stem cell grafts than pediatric patients, which may reflect differences in practice in pediatric versus adult treatment centers. The proportions of donor types also differ those in adult and pediatric populations. Outcomes for patients in the AYA age range are similar to those of pediatric patients for acute myelogenous leukemia but worse for acute lymphoblastic leukemia. Outcomes for both leukemias are better in AYA patients compared with older adults. Comparing the time periods 2000 to 2009 and 2010 to 2019 revealed significant improvement in overall survival across the age spectrum, but the greatest improvement in the AYA age group.

Adding Centralized Electronic Patient-Reported Outcome Data Collection to an Established International Clinical Outcomes Registry.

The importance of patient-reported outcomes (PROs) in cellular therapies, including hematopoietic cell transplantation (HCT) is highlighted in this study. Longitudinal collection of PROs in a registry is recommended for several reasons, yet to date, PROs are not routinely collected from HCT patients to augment clinical registry data. The aim of this study was to determine the feasibility of electronic PRO data collection by a national clinical outcomes registry, by assessing differences between who does and does not report PROs. We conducted a cross-sectional pilot collection of PROs from HCT recipients after treatment using computer-adapted tests from the Patient-Reported Outcome Measurement Information System (PROMIS). We implemented centralized data collection through the Center for International Blood and Marrow Transplant Research (CIBMTR) among patients who underwent HCT for myelodysplastic syndromes (MDS), were at least 6 months post-HCT, and spoke English or Spanish. The main objective was identifying patient, disease, and transplant-related differences associated with completion of electronic PROs. Patients were excluded from analysis if they were determined to be ineligible (deceased, did not speak English or Spanish, refused to be contacted by the CIBMTR). A total of 163 patients were contacted and potentially eligible to participate; of these, 92 (56%) enrolled and 89 (55%) completed the PRO assessment. The most frequent reason for incomplete surveys was inability to contact patients (n = 88), followed by declining to participate in the study (n = 37). There were no sociodemographic or age differences between those who completed the PRO survey (n = 89) and eligible nonresponders (n = 155). Patient scores were within 3 points of the US average of 50 for all symptoms and functioning except physical functioning. Responders and nonresponders did not exhibit meaningfully different sociodemographic characteristics. Difficulty contacting patients posed the greatest barrier and also provided the greatest opportunity for improvement. Once enrolled, survey completion was high. These results support standardizing centralized PRO data collection through the CIBMTR registry.

Male-Specific Late Effects in Adult Hematopoietic Cell Transplantation Recipients: A Systematic Review from the Late Effects and Quality of Life Working Committee of the Center for International Blood and Marrow Transplant Research and Transplant Complications Working Party of the European Society of Blood and Marrow Transplantation.

Male-specific late effects after hematopoietic cell transplantation (HCT) include genital chronic graft-versus-host disease (GVHD), hypogonadism, sexual dysfunction, infertility, and subsequent malignancies, such as prostate, penile, and testicular cancer. These effects may be closely intertwined and cause prolonged morbidity and decreased quality of life after HCT. Here we provide a systematic review of male-specific late effects in a collaboration among transplantation physicians, endocrinologists, urologists, dermatologists, and sexual health professionals through the Late Effects and Quality of Life Working Committee of the Center for International Blood and Marrow Transplant Research and the Transplant Complications Working Party of the European Society of Blood and Marrow Transplantation. We used a systematic review methodology to summarize incidence, risk factors, screening, prevention, and treatment of these complications and provide consensus evidence-based recommendations for clinical practice and future research. Most of the evidence regarding male GVHD is still based on limited data, precluding strong therapeutic recommendations. Therefore, we recommend systematic screening for male genital GVHD regularly and reporting of cases to large registries to allow for a better understanding. Future research also should address treatment, given the little published evidence currently available. Male-specific endocrine consequences of HCT include hypogonadism, which also may affect bone health. Given the scanty evidence, current recommendations for hormone substitution and/or bone health treatment are based on similar principles as for the general population. Following HCT, sexual health decreases, and this topic should be addressed at regular intervals. Future studies should focus on interventional strategies to address sexual dysfunction. Infertility remains prevalent in patients having undergone myeloablative conditioning, warranting the offer of sperm preservation for all HCT candidates. Most studies on fertility rely on descriptive registry analysis and surveys, underscoring the importance of reporting post-HCT conception data to large registries. Although the quality of evidence is low, the development of cancer in male genital organs does not seem more prevalent in HCT recipients compared with the general population; however, subsequent malignancies in general seem to be more prevalent in males than in females, and special attention should be given to skin and oral mucosa. Male-specific late effects, which likely are more underreported than female-specific complications, should be systematically considered during the regular follow-up visits of male survivors who have undergone HCT. Care of patients with male-specific late effects warrants close collaboration between transplantation physicians and specialists from other involved disciplines. Future research should be directed toward better data collection on male-specific late effects and on studies about the interrelationships among these late effects, to allow the development of evidence-based effective management practices.

Blood and Marrow Transplant Clinical Trials Network Study 1102 heralds a new era in hematopoietic cell transplantation in high-risk myelodysplastic syndromes: Challenges and opportunities in implementation.

LAY SUMMARY: People who have advanced myelodysplastic syndromes (MDS) may live longer if they get a bone marrow transplant (BMT) instead of other therapies. However, only 15% of people with MDS actually get BMT. Experts say community physicians and transplant physicians should team up with insurance companies and patient advocacy groups to 1) spread this news about lifesaving advances in BMT, 2) ensure that everyone can afford health care, 3) provide emotional support for patients and families, 4) help patients and families get transportation and housing if they need to travel for transplant, and 5) improve care for people of under-represented racial and ethnic backgrounds.

Barriers to Access to Hematopoietic Cell Transplantation among Patients with Acute Myeloid Leukemia in Virginia.

Allogeneic hematopoietic cell transplantation (HCT) is a standard therapy for patients with intermediate to high-risk acute myeloid leukemia (AML) and is associated with improved long-term disease-free survival. Disparity exists in access to HCT among different patient populations and requires further study. In this study, we compared HCT rates for AML among different regions in the state of Virginia and identified geographic and socioeconomic factors associated with the likelihood of receiving HCT. We conducted a retrospective, cohort study of patients 18 to 74 years of age diagnosed with AML in Virginia from 2013 to 2017 as reported to the Virginia Cancer Registry (VCR); the VCR was further linked with the Center for International Blood and Marrow Transplant Research database for identification of patients who had undergone HCT within 2 years of diagnosis. Socioeconomic data were generated from the VCR and the American Community Survey. Univariate and multivariable logistic regression models were used to examine selected socioeconomic factors of interest, including patient-level information such as sex, age, race, marital status, and primary insurance payer, as well as factors associated with geography, including the Social Vulnerability Index (SVI) and percentage of African Americans residing in the region. In Virginia, 818 patients were diagnosed with AML from 2013 to 2017, and, of these, 168 patients (21%) underwent HCT within 2 years of diagnosis. Median age was lower in the HCT cohort (55 years) versus the non-HCT cohort (64 years) (P < .001). There was a higher proportion of married patients in the HCT cohort (67%) versus the non-HCT cohort (53%) (P = .005). The rate of HCT varied by geographic region (P = .004). The multivariable analyses (without including SVI) showed decreased likelihood of HCT with increasing age (odds ratio [OR], .96; 95% confidence interval [CI], .95 to .98). Patients from regions that had a greater than 25% African American population were less likely to undergo HCT (OR, .58; 95% CI, .38 to .89). Patients who were not married were less likely to undergo HCT compared with married patients (OR, .56; 95% CI, .36 to .88). Patients with government-sponsored insurance as the primary payer were less likely to undergo HCT compared with patients with private insurance (OR, .49; 95% CI, .32 to .77). Patients living in Zip Code areas with a greater percentage of population with a bachelor's or graduate degree were more likely to undergo HCT (OR, 1.02; 95% CI, 1.00 to 1.03). In a separate multivariate model with SVI, patients residing in a Zip Code with higher SVI were less likely to undergo HCT (OR, .37; 95% CI, .16 to .82). From 2013 to 2017, we found that the likelihood of a patient undergoing HCT in Virginia for AML within 2 years of diagnosis was negatively associated with increasing age, percent of African Americans residing in the region, not-married relationship status, government-sponsored insurance as primary payer, higher SVI, and decreased percent of population with a bachelor's or graduate degree. Resources should be directed toward at-risk patient populations to remove barriers to improve access to HCT. The SVI can be used to identify communities at risk nationwide.

Biobehavioral Research and Hematopoietic Stem Cell Transplantation: Expert Review from the Biobehavioral Research Special Interest Group of the American Society for Transplantation and Cellular Therapy.

Hematopoietic stem cell transplantation (HCT) is a potentially curative treatment for many hematologic conditions. Despite advances in conditioning and supportive measures, however, there remain significant comorbidities that threaten survivorship. Adverse effects of stress-related biobehavioral processes-defined here as the interactions of behavioral, psychological, and socioenvironmental factors with biology-impact immune recovery and function and are particularly salient in the HCT context, given the importance of immune reconstitution for improved survivorship. However, biobehavioral processes have been underinvestigated in this vulnerable group compared with other cancer populations. Here the Biobehavioral Research Special Interest Group (SIG) of the American Society for Transplantation and Cellular Therapy provides an expert review to inform research directions explicating the biological correlates of behavioral symptoms and evaluate the impact of these on HCT outcomes. The goal of this expert review is to provide a foundation for advancing science that effectively integrates behavioral and biological processes to optimize quality of life and improve clinical outcomes for HCT recipients.

Systematic Reviews in Hematopoietic Cell Transplantation and Cellular Therapy: Considerations and Guidance from the American Society for Transplantation and Cellular Therapy, European Society for Blood and Marrow Transplantation, and Center for International Blood and Marrow Transplant Research Late Effects and Quality of Life Working Committee.

Systematic reviews apply rigorous methodologies to address a prespecified, clearly formulated clinical research question. The conclusion that results is often cited to more robustly inform decision making by clinicians, third-party payers, and managed care organizations about the clinical question of interest. Although systematic reviews provide a rigorous standard, they may be infeasible when the task is to create general disease-focused guidelines comprising multiple clinical practice questions versus a single major clinical practice question. Collaborating transplantation and cellular therapy society committees also recognize that the quantity and or quality of reference sources may be insufficient for a meaningful systematic review. As the conduct of systematic reviews has evolved over time in terms of grading systems, reporting requirements, and use of technology, here we provide current guidance on methodologies, resources for reviewers, and approaches to overcome challenges in conducting systematic reviews in transplantation and cellular therapy.

National Marrow Donor Program-Sponsored Multicenter, Phase II Trial of HLA-Mismatched Unrelated Donor Bone Marrow Transplantation Using Post-Transplant Cyclophosphamide.

PURPOSE: Hematopoietic cell transplantation (HCT) is curative for hematologic disorders, but outcomes are historically inferior when using HLA-mismatched donors. Despite unrelated donor registries listing > 38 million volunteers, 25%-80% of US patients lack an HLA-matched unrelated donor, with significant disparity across ethnic groups. We hypothesized that HCT with a mismatched unrelated donor (MMUD) using post-transplant cyclophosphamide (PTCy), a novel strategy successful in overcoming genetic disparity using mismatched related donors, would be feasible and increase access to HCT. PATIENTS AND METHODS: We performed a prospective phase II study of MMUD bone marrow HCT with PTCy for patients with hematologic malignancies. The primary end point was 1-year overall survival (OS), hypothesized to be 65% or better. 80 patients enrolled at 11 US transplant centers (December 2016-March 2019). Following myeloablative or reduced-intensity conditioning-based HCT, patients received PTCy on days +3, +4, with sirolimus and mycophenolate mofetil starting on day +5. We compared outcomes to Center for International Blood and Marrow Transplant Research contemporary controls receiving PTCy. RESULTS: Notably, 48% of patients enrolled were ethnic minorities. 39% of pairs were matched for 4-6 out of 8 HLA alleles. The primary end point was met, with 1-year OS of 76% (90% CI, 67.3 to 83.3) in the entire cohort, and 72% and 79% in the myeloablative and reduced-intensity conditioning strata, respectively. Secondary end points related to engraftment and graft-versus-host-disease were reached. Multivariate analysis comparing the study group with other mismatched HCT controls found no significant differences in OS. CONCLUSION: Our prospective study demonstrates the feasibility and effectiveness of HCT with an MMUD in the setting of PTCy. Remarkably, nearly half of the study participants belonged to an ethnic minority population, suggesting this approach may significantly expand access to HCT.