Neighborhood poverty and pediatric allogeneic hematopoietic cell transplantation outcomes: a CIBMTR analysis.

Social determinants of health, including poverty, contribute significantly to health outcomes in the United States; however, their impact on pediatric hematopoietic cell transplantation (HCT) outcomes is poorly understood. We aimed to identify the association between neighborhood poverty and HCT outcomes for pediatric allogeneic HCT recipients in the Center for International Blood and Marrow Transplant Research database. We assembled 2 pediatric cohorts undergoing first allogeneic HCT from 2006 to 2015 at age ≤18 years, including 2053 children with malignant disease and 1696 children with nonmalignant disease. Neighborhood poverty exposure was defined a priori per the US Census definition as living in a high-poverty ZIP code (≥20% of persons below 100% federal poverty level) and used as the primary predictor in all analyses. Our primary outcome was overall survival (OS), defined as the time from HCT until death resulting from any cause. Secondary outcomes included relapse and transplantation-related mortality (TRM) in malignant disease, acute and chronic graft-versus-host disease, and infection in the first 100 days post-HCT. Among children undergoing transplantation for nonmalignant disease, neighborhood poverty was not associated with any HCT outcome. Among children undergoing transplantation for malignant disease, neighborhood poverty conferred an increased risk of TRM but was not associated with inferior OS or any other transplantation outcome. Among children with malignant disease, a key secondary finding was that children with Medicaid insurance experienced inferior OS and increased TRM compared with those with private insurance. These data suggest opportunities for future investigation of the effects of household-level poverty exposure on HCT outcomes in pediatric malignant disease to inform care delivery interventions.

Safety, Tolerability, and Population Pharmacokinetics of Intravenous and Oral Isavuconazonium Sulfate in Pediatric Patients.

Isavuconazole, administered as the water-soluble prodrug isavuconazonium sulfate, is a new triazole agent used to treat invasive fungal infections. This phase 1 study evaluated the pharmacokinetics (PK), safety, and tolerability of isavuconazole in 46 immunocompromised pediatric patients, stratified by age (1 to <6 [intravenous (i.v.) only], 6 to <12, and 12 to <18 years), receiving 10 mg/kg body weight (maximum, 372 mg) isavuconazonium sulfate either i.v. or orally. A population PK model using weight-based allometric scaling was constructed with the pediatric i.v. and oral data plus i.v. data from a phase 1 study in adults. The best model was a 3-compartment model with combined zero-order and first-order input, with linear elimination. Stepwise covariate modeling was performed in Perl-speaks-NONMEM version 4.7.0. None of the covariates examined, including age, sex, race, and body mass index, were statistically significant for any of the PK parameters. The area under the concentration-time curve at steady state (AUCSS) was predicted for pediatric patients using 1,000 Monte Carlo simulations per age cohort for each administration route. The probability of target attainment (AUCSS range, 60 to 233 µg · h/ml) was estimated; this target range was derived from plasma drug exposures in adults receiving the recommended clinical dose. Predicted plasma drug exposures were within the target range for >80% and >76% of simulated pediatric patients following i.v. or oral administration, respectively. Intravenous and oral administration of isavuconazonium sulfate at the studied dosage of 10 mg/kg was well tolerated and resulted in exposure in pediatric patients similar to that in adults. (This study has been registered at ClinicalTrials.gov under identifier NCT03241550).

HLA-Haploidentical Hematopoietic Cell Transplantation for Treatment of Nonmalignant Diseases Using Nonmyeloablative Conditioning and Post-Transplant Cyclophosphamide.

Allogeneic hematopoietic cell transplant (HCT) is often the only curative therapy for patients with nonmalignant diseases; however, many patients do not have an HLA-matched donor. Historically, poor survival has been seen after HLA-haploidentical HCT because of poor immune reconstitution, increased infections, graft-versus-host disease (GVHD), and graft failure. Encouraging results have been reported using a nonmyeloablative T cell-replete HLA-haploidentical transplant approach in patients with hematologic malignancies. Here we report the outcomes of 23 patients with various nonmalignant diseases using a similar approach. Patients received HLA-haploidentical bone marrow (n = 17) or granulocyte colony-stimulating factor-mobilized peripheral blood stem cell (n = 6) grafts after conditioning with cyclophosphamide 50 mg/kg, fludarabine 150 mg/m2, and 2 or 4 Gy total body irradiation. Postgrafting immunosuppression consisted of cyclophosphamide, mycophenolate mofetil, tacrolimus, ± sirolimus. Median patient age at HCT was 10.8 years. Day 100 transplant-related mortality (TRM) was 0%. Two patients died at later time points, 1 from intracranial hemorrhage/disseminated fungal infection in the setting of graft failure and 1 from infection/GVHD. The estimated probabilities of grades II to IV and III to IV acute GVHD at day 100 and 2-year National Institutes of Health consensus chronic GVHD were 78%, 26%, and 42%, respectively. With a median follow-up of 2.5 years, the 2-year overall and event-free rates of survival were 91% and 78%, respectively. These results are encouraging and demonstrate favorable disease-specific lineage engraftment with low TRM in patients with nonmalignant diseases using nonmyeloablative conditioning followed by T cell-replete HLA-haploidentical grafts. However, additional strategies are needed for GVHD prevention to make this a viable treatment approach for patients with nonmalignant diseases.

Infantile Myelofibrosis and Myeloproliferation with CDC42 Dysfunction.

Studies of genetic blood disorders have advanced our understanding of the intrinsic regulation of hematopoiesis. However, such genetic studies have only yielded limited insights into how interactions between hematopoietic cells and their microenvironment are regulated. Here, we describe two affected siblings with infantile myelofibrosis and myeloproliferation that share a common de novo mutation in the Rho GTPase CDC42 (Chr1:22417990:C>T, p.R186C) due to paternal germline mosaicism. Functional studies using human cells and flies demonstrate that this CDC42 mutant has altered activity and thereby disrupts interactions between hematopoietic progenitors and key tissue microenvironmental factors. These findings suggest that further investigation of this and other related disorders may provide insights into how hematopoietic cell-microenvironment interactions play a role in human health and can be disrupted in disease. In addition, we suggest that deregulation of CDC42 may underlie more common blood disorders, such as primary myelofibrosis.

Impact of cytogenetic abnormalities on outcomes of adult Philadelphia-negative acute lymphoblastic leukemia after allogeneic hematopoietic stem cell transplantation: a study by the Acute Leukemia Working Committee of the Center for International Blood and Marrow Transplant Research.

Cytogenetic risk stratification at diagnosis has long been one of the most useful tools to assess prognosis in acute lymphoblastic leukemia (ALL). To examine the prognostic impact of cytogenetic abnormalities on outcomes after allogeneic hematopoietic cell transplantation, we studied 1731 adults with Philadelphia-negative ALL in complete remission who underwent myeloablative or reduced intensity/non-myeloablative conditioning transplant from unrelated or matched sibling donors reported to the Center for International Blood and Marrow Transplant Research. A total of 632 patients had abnormal conventional metaphase cytogenetics. The leukemia-free survival and overall survival rates at 5 years after transplantation in patients with abnormal cytogenetics were 40% and 42%, respectively, which were similar to those in patients with a normal karyotype. Of the previously established cytogenetic risk classifications, modified Medical Research Council-Eastern Cooperative Oncology Group score was the only independent prognosticator of leukemia-free survival (P=0.03). In the multivariable analysis, monosomy 7 predicted post-transplant relapse [hazard ratio (HR)=2.11; 95% confidence interval (95% CI): 1.04-4.27] and treatment failure (HR=1.97; 95% CI: 1.20-3.24). Complex karyotype was prognostic for relapse (HR=1.69; 95% CI: 1.06-2.69), whereas t(8;14) predicted treatment failure (HR=2.85; 95% CI: 1.35-6.02) and overall mortality (HR=3.03; 95% CI: 1.44-6.41). This large study suggested a novel transplant-specific cytogenetic scheme with adverse [monosomy 7, complex karyotype, del(7q), t(8;14), t(11;19), del(11q), tetraploidy/near triploidy], intermediate (normal karyotype and all other abnormalities), and favorable (high hyperdiploidy) risks to prognosticate leukemia-free survival (P=0.02). Although some previously established high-risk Philadelphia-negative cytogenetic abnormalities in ALL can be overcome by transplantation, monosomy 7, complex karyotype, and t(8;14) continue to pose significant risks and yield inferior outcomes.

The Concentration of Total Nucleated Cells in Harvested Bone Marrow for Transplantation Has Decreased over Time.

Bone marrow (BM) is an essential source of hematopoietic stem cell grafts for many allogeneic hematopoietic cell transplant (HCT) recipients, including adult patients (for specific diseases and transplantation strategies) and the majority of pediatric recipient. However, since the advent of granulocyte colony-stimulating factor-mobilized peripheral blood stem cell (PBSC) grafts, there has been a significant decrease in the use of BM in HCT, thought to be due mainly to the increased logistical challenges in harvesting BM compared with PBSCs, as well as generally no significant survival advantage of BM over PBSCs. The decreased frequency of collection has the potential to impact the quality of BM harvests. In this study, we examined >15,000 BM donations collected at National Marrow Donor Program centers between 1994 and 2016 and found a significant decline in the quality of BM products, as defined by the concentration of total nucleated cells (TNCs). The mean TNC concentration in BM donations dropped from 21.8 × 106 cells/mL in the earliest era (1994 to 1996) to 18.7 × 106 cells/mL in the most recent era (2012 to 2016) (means ratio, .83; P < .001). This decline in BM quality was seen despite the selection of more donors perceived to be optimal (eg, younger and male). Multivariate regression analysis showed that higher-volume centers (performing >30 collections per era) had better-quality harvests with higher concentrations of TNCs collected. In conclusion, we have identified a significant decrease in the quality of BM collections over time, and lower-volume collection centers had poorer-quality harvests. In this analysis, we could not elucidate the direct cause for this finding, suggesting the need for further studies to investigate the key factors responsible and to explore the impact on transplant recipients.

Transplantation Outcomes for Children with Hypodiploid Acute Lymphoblastic Leukemia.

Children with hypodiploid acute lymphoblastic leukemia (ALL) have inferior outcomes despite intensive risk-adapted chemotherapy regimens. We describe 78 children with hypodiploid ALL who underwent hematopoietic stem cell transplantation between 1990 and 2010. Thirty-nine (50%) patients had ≤ 43 chromosomes, 12 (15%) had 44 chromosomes, and 27 (35%) had 45 chromosomes. Forty-three (55%) patients underwent transplantation in first remission (CR1) and 35 (45%) underwent transplantation in ≥ second remission (CR2). Twenty-nine patients (37%) received a graft from a related donor and 49 (63%) from an unrelated donor. All patients received a myeloablative conditioning regimen. The 5-year probabilities of leukemia-free survival, overall survival, relapse, and treatment-related mortality for the entire cohort were 51%, 56%, 27%, and 22%, respectively. Multivariate analysis confirmed that mortality risks were higher for patients who underwent transplantation in CR2 (hazard ratio, 2.16; P = .05), with number of chromosomes ≤ 43 (hazard ratio, 2.15; P = .05), and for those who underwent transplantation in the first decade of the study period (hazard ratio, 2.60; P = .01). Similarly, treatment failure risks were higher with number of chromosomes ≤ 43 (hazard ratio, 2.28; P = .04) and the earlier transplantation period (hazard ratio, 2.51; P = .01). Although survival is better with advances in donor selection and supportive care, disease-related risk factors significantly influence transplantation outcomes.

Long-term survival and late effects among one-year survivors of second allogeneic hematopoietic cell transplantation for relapsed acute leukemia and myelodysplastic syndromes.

We analyzed the outcomes of patients who survived disease-free for 1 year or more after a second allogeneic hematopoietic cell transplantation (HCT) for relapsed acute leukemia or myelodysplastic syndromes between 1980 and 2009. A total of 1285 patients received a second allogeneic transplant after disease relapse; among these, 325 were relapse free at 1 year after the second HCT. The median time from first to second HCT was 17 and 24 months for children and adults, respectively. A myeloablative preparative regimen was used in the second transplantation in 62% of children and 45% of adult patients. The overall 10-year conditional survival rates after second transplantation in this cohort of patients who had survived disease-free for at least 1 year was 55% in children and 39% in adults. Relapse was the leading cause of mortality (77% and 54% of deaths in children and adults, respectively). In multivariate analyses, only disease status before second HCT was significantly associated with higher risk for overall mortality (hazard ratio, 1.71 for patients with disease not in complete remission before second HCT, P < .01). Chronic graft-versus-host disease (GVHD) developed in 43% and 75% of children and adults after second transplantation. Chronic GVHD was the leading cause of nonrelapse mortality, followed by organ failure and infection. The cumulative incidence of developing at least 1 of the studied late effects within 10 years after second HCT was 63% in children and 55% in adults. The most frequent late effects in children were growth disturbance (10-year cumulative incidence, 22%) and cataracts (20%); in adults they were cataracts (20%) and avascular necrosis (13%). Among patients with acute leukemia and myelodysplastic syndromes who receive a second allogeneic HCT for relapse and survive disease free for at least 1 year, many can be expected to survive long term. However, they continue to be at risk for relapse and nonrelapse morbidity and mortality. Novel approaches are needed to minimize relapse risk and long-term transplantation morbidity in this population.

Increasing incidence of chronic graft-versus-host disease in allogeneic transplantation: a report from the Center for International Blood and Marrow Transplant Research.

Although transplant practices have changed over the last decades, no information is available on trends in incidence and outcome of chronic graft-versus-host disease (cGVHD) over time. This study used the central database of the Center for International Blood and Marrow Transplant Research (CIBMTR) to describe time trends for cGVHD incidence, nonrelapse mortality, and risk factors for cGVHD. The 12-year period was divided into 3 intervals, 1995 to 1999, 2000 to 2003, and 2004 to 2007, and included 26,563 patients with acute leukemia, chronic myeloid leukemia, and myelodysplastic syndrome. Multivariate analysis showed an increased incidence of cGVHD in more recent years (odds ratio = 1.19, P < .0001), and this trend was still seen when adjusting for donor type, graft type, or conditioning intensity. In patients with cGVHD, nonrelapse mortality has decreased over time, but at 5 years there were no significant differences among different time periods. Risk factors for cGVHD were in line with previous studies. This is the first comprehensive characterization of the trends in cGVHD incidence and underscores the mounting need for addressing this major late complication of transplantation in future research.

Hospital length of stay in the first 100 days after allogeneic hematopoietic cell transplantation for acute leukemia in remission: comparison among alternative graft sources.

Several studies have shown comparable survival outcomes with different graft sources, but the relative resource needs of hematopoietic cell transplantation (HCT) by graft source have not been well studied. We compared total hospital length of stay in the first 100 days after HCT in 1577 patients with acute leukemia in remission who underwent HCT with an umbilical cord blood (UCB), matched unrelated donor (MUD), or mismatched unrelated donor (MMUD) graft between 2008 and 2011. To ensure a relatively homogenous study population, the analysis was limited to patients with acute myelogenous leukemia and acute lymphoblastic leukemia in first or second complete remission who underwent HCT in the United States. To account for early deaths, we compared the number of days alive and out of the hospital in the first 100 days post-transplantation. For children who received myeloablative conditioning, the median time alive and out of the hospital in the first 100 days was 50 days for single UCB recipients, 54 days for double UCB recipients, and 60 days for MUD bone marrow (BM) recipients. In multivariate analysis, use of UCB was significantly associated with fewer days alive and out of the hospital compared with MUD BM. For adults who received myeloablative conditioning, the median time alive and out of the hospital in first 100 days was 52 days for single UCB recipients, 55 days for double UCB recipients, 69 days for MUD BM recipients, 75 days for MUD peripheral blood stem cell (PBSC) recipients, 63 days for MMUD BM recipients, and 67 days for MMUD PBSC recipients. In multivariate analysis, UCB and MMUD BM recipients had fewer days alive and out of the hospital compared with recipients of other graft sources. For adults who received a reduced-intensity preparative regimen, the median time alive and out of the hospital during the first 100 days was 65 days for single UCB recipients, 63 days for double UCB recipients, 79 days for MUD PBSC recipients, and 79 days for MMUD PBSC recipients. Similar to the other 2 groups, receipt of UCB was associated with a fewer days alive and out of the hospital. In conclusion, length of stay in the first 100 days post-transplantation varies by graft source and is longer for UCB HCT recipients. These data provide insight into the resource needs of patients who undergo HCT with these various graft sources.

Avascular necrosis of bone after allogeneic hematopoietic cell transplantation in children and adolescents.

We conducted a nested case-control study within a cohort of 6244 patients to assess risk factors for avascular necrosis (AVN) of bone in children and adolescents after allogeneic transplantation. Eligible patients were ≤21 years of age, received their first allogeneic transplant between 1990 and 2008 in the United States, and had survived ≥ 6 months from transplantation. Overall, 160 patients with AVN and 478 control subjects matched by year of transplant, length of follow-up and transplant center were identified. Patients and control subjects were confirmed via central review of radiology, pathology, and/or surgical procedure reports. Median time from transplant to diagnosis of AVN was 14 months. On conditional logistic regression, increasing age at transplant (≥5 years), female gender, and chronic graft-versus-host disease (GVHD) were significantly associated with increased risks of AVN. Compared with patients receiving myeloablative regimens for malignant diseases, lower risks of AVN were seen in patients with nonmalignant diseases and those who had received reduced-intensity conditioning regimens for malignant diseases. Children at high risk for AVN include those within the age group where rapid bone growth occurs as well as those who experience exposure to myeloablative conditioning regimens and immunosuppression after hematopoietic cell transplantation for the treatment of GVHD. More research is needed to determine whether screening strategies specifically for patients at high risk for developing AVN with early interventions may mitigate the morbidity associated with this complication.

Outcome of myeloablative conditioning and unrelated donor hematopoietic cell transplantation for childhood acute lymphoblastic leukemia in third remission.

We conducted a retrospective study of 155 children who underwent unrelated donor hematopoietic cell transplantation (HCT) between 1990 and 2005 for acute lymphoblastic leukemia in third remission. The median patient age was 11 years, the median time from diagnosis to first relapse was 36 months, and the median time from first relapse to second relapse was 26 months. Stem cell sources were bone marrow (n = 115), peripheral blood (n = 11), and cord blood (n = 29). All patients received a myeloablative pretransplantation conditioning regimen. The 5-year estimates of leukemia-free survival, relapse, and nonrelapse mortality were 30%, 25%, and 45%, respectively. In multivariate analysis, the only risk factor associated with relapse was the interval between the first relapse and the second relapse. Second relapses occurring >26 months from the first relapse were associated with lower risk for post-HCT relapse compared with second relapses occurring at ≤26 months (relative risk, 0.4; P = .01). Relapse risk was lowest when late second relapse was preceded by late first relapse (>36 months from diagnosis), as demonstrated by a 3-year relapse rate of 9% (P = .0009). Our data indicate that long-term leukemia-free survival can be achieved in children with acute lymphoblastic leukemia in third remission using unrelated donor HCT, especially when the second relapse occurs late.

Impact of depth of clinical response on outcomes of acute myeloid leukemia patients in first complete remission who undergo allogeneic hematopoietic cell transplantation.

Acute myeloid leukemia (AML) patients often undergo allogeneic hematopoietic cell transplantation (alloHCT) in first complete remission (CR). We examined the effect of depth of clinical response, including incomplete count recovery (CRi) and/or measurable residual disease (MRD), in patients from the Center for International Blood and Marrow Transplantation Research (CIBMTR) registry. We identified 2492 adult patients (1799 CR and 693 CRi) who underwent alloHCT between January 1, 2007 and December 31, 2015. The primary outcome was overall survival (OS). Multivariable analysis was performed to adjust for patient-, disease-, and transplant-related factors. Baseline characteristics were similar. Patients in CRi compared to those in CR had an increased likelihood of death (HR: 1.27; 95% confidence interval: 1.13-1.43). Compared to CR, CRi was significantly associated with increased non-relapse mortality (NRM), shorter disease-free survival (DFS), and a trend toward increased relapse. Detectable MRD was associated with shorter OS, shorter DFS, higher NRM, and increased relapse compared to absence of MRD. The deleterious effects of CRi and MRD were independent. In this large CIBMTR cohort, survival outcomes differ among AML patients based on depth of CR and presence of MRD at the time of alloHCT. Further studies should focus on optimizing post-alloHCT outcomes for patients with responses less than CR.

Use of intravenous zanamivir after development of oseltamivir resistance in a critically Ill immunosuppressed child infected with 2009 pandemic influenza A (H1N1) virus.

Immunosuppressed patients receiving oseltamivir for 2009 novel H1N1 influenza A infection may develop drug resistance, leading to treatment failure. Intravenous zanamivir was administered on a compassionate-use basis to a profoundly immunosuppressed pediatric patient with severe oseltamivir-resistant novel H1N1 pneumonia. The regimen was well tolerated and was associated with a decrease in viral burden.

Outcomes of hematologic malignancies after unrelated donor hematopoietic cell transplantation according to place of residence.

Studies suggest that patients who live in rural areas may have worse clinical outcomes compared with patients living in urban areas. We studied whether place of residence (rural versus urban) is associated with clinical outcomes of patients with leukemia or myelodysplastic syndrome (MDS) who received an unrelated donor hematopoietic cell transplantation (HCT). Patients' residential ZIP code at the time of transplant was used to determine rural or urban designation based on the Rural Urban Commuting Codes. The study included 6140 patients reported to the Center for International Blood and Marrow Transplant Research (CIBMTR) from 121 U.S. HCT centers: 1179 (19%) came from rural areas, whereas 4961 (81%) came from urban areas. Rural and urban patients were similar in patient-, disease-, and transplant-related characteristics aside from household income and distance traveled to the HCT center. After adjusting for income and other significant patient, disease, and transplant-related variables, the risk of overall mortality between patients residing in rural and urban areas were not statistically significant (relative risk 1.01, 95% confidence intervals 0.93-1.10, P = .74). Similar outcomes were noted for treatment-related mortality (TRM), disease-free survival (DFS), and relapse. Patient's income, derived from the U.S. Census and based on their residential ZIP code, was independently associated with outcomes. In summary, our study showed no differences in the clinical outcomes of patients from rural or urban areas after unrelated donor HCT.

Impact of conditioning regimen in allogeneic hematopoetic stem cell transplantation for children with acute myelogenous leukemia beyond first complete remission: a pediatric blood and marrow transplant consortium (PBMTC) study.

Total body irradiation (TBI)-based conditioning regimens for pediatric patients with acute myelogenous leukemia (AML) beyond first complete remission (CR1) are controversial. Because the long-term morbidity of busulfan (Bu)-based regimens appears to be lower, determining efficacy is critical. We retrospectively evaluated 151 pediatric patients with AML beyond CR1, comparing outcomes in 90 patients who received a TBI-based conditioning regimen and 61 patients who received a Bu-based conditioning regimen. There were no differences between the 2 groups with respect to age, sex, duration of CR1, time from most recent remission to transplantation, or donor source. The probability of relapse at 2 years also did not differ between the 2 groups (26% and 27%, respectively; P=.93). No significant difference in event-free survival (EFS) (P=.29) or overall survival (OS) (P=.11) was noted between the 2 groups. These findings were supported by a multivariate analysis in which TBI was not associated with improved EFS (hazard ratio [HR]=1.17; 95% confidence interval [CI]=0.66-2.10; P=.58) or OS (HR=1.42; 95% CI=0.76-2.64; P=.27). Shorter CR1 and receiving an HLA-mismatched transplant adversely affected EFS and OS in this cohort. Our study provides no evidence of an advantage to using TBI in children with AML beyond CR1. A prospective, randomized study is needed to confirm these results.

Race and socioeconomic status influence outcomes of unrelated donor hematopoietic cell transplantation.

Success of hematopoietic cell transplantation (HCT) can vary by race, but the impact of socioeconomic status (SES) is not known. To evaluate the role of race and SES, we studied 6207 unrelated-donor myeloablative (MA) HCT recipients transplanted between 1995 and 2004 for acute or chronic leukemia or myelodysplastic syndrome (MDS). Patients were reported by transplant center to be White (n = 5253), African American (n = 368), Asian/Pacific-Islander (n = 141), or Hispanic (n = 445). Patient income was estimated from residential zip code at time of HCT. Cox regression analysis adjusting for other significant factors showed that African American (but not Asian or Hispanic) recipients had worse overall survival (OS) (relative-risk [RR] 1.47; 95% confidence interval [CI] 1.29-1.68, P < .001) compared to Whites. Treatment-related mortality (TRM) was higher in African Americans (RR 1.56; 95% CI 1.34-1.83, P < .001) and in Hispanics (RR 1.30; 95% CI 1.11-1.51, P = .001). Across all racial groups, patients with median incomes in the lowest quartile (<$34,700) had worse OS (RR 1.15; 95% CI 1.04-1.26, P = .005) and higher risks of TRM (RR 1.21; 1.07-1.36, P = .002). Inferior outcomes among African Americans are not fully explained by transplant-related factors or SES. Potential other mechanisms such as genetic polymorphisms that have an impact on drug metabolism or unmeasured comorbidities, socioeconomic factors, and health behaviors may be important. Low SES, regardless of race, has a negative impact on unrelated donor HCT outcomes.

Survival Trends in Infants Undergoing Allogeneic Hematopoietic Cell Transplant.

Importance: Studies demonstrating improved survival after allogeneic hematopoietic cell transplant generally exclude infants. Objective: To analyze overall survival trends and other outcomes among infants who undergo allogeneic hematopoietic cell transplant. Design, Setting, and Participants: In this cohort study, we used time-trend analysis to evaluate 3 periods: 2000 through 2004, 2005 through 2009, and 2010 through 2014. The study was conducted in a multicenter setting through the Center for International Blood and Marrow Transplant Research, which is made up of a voluntary working group of more than 450 transplant centers worldwide. Two groups of infants aged 1 year or younger in 2 cohorts were included: those with malignant conditions, such as leukemia, and those with nonmalignant disorders, including immunodeficiencies. Data analysis was conducted from July 2017 to December 2018. Exposures: Allogeneic hematopoietic cell transplant. Main Outcomes and Measures: Survival trends, disease relapse, and toxicity. Results: A total of 2498 infants with a median age of 7 months (range, <1-12 months) were included. In the nonmalignant cohort (n = 472), survival rates improved from the first to the second period (hazard ratio, 0.77 [95% CI, 0.63-0.93]; P = .007) but did not change after 2004. Compared with infants with nonmalignant diseases (n = 2026; 3-year overall survival: 2000-2004, 375/577 [65.0%]; 2005-2009, 503/699 [72.0%]; and 2010-2014, 555/750 [74.0%]), those with malignant conditions had poorer survival rates, without improvement over time (3-year overall survival: 2000-2004, 109/199 [54.8%]; 2005-2009, 104/161 [64.6%]; and 2010-2014, 66/112 [58.9%]). From 2000 through 2014, relapse rates increased in infants with malignant conditions (3-year relapse rate: 2000-2004, 19% [95% CI, 14%-25%]; 2005-2009, 23% [95% CI, 17%-30%]; 2010-2014, 36% [95% CI, 27%-46%]; P = .01). Sinusoidal obstruction syndrome was frequent, occurring with a cumulative incidence of 13% (95% CI, 11%-16%) of infants with nonmalignant diseases and 32% (95% CI, 22%-42%) of those with malignant diseases. Generally, recipients of human leukocyte antigen-identical sibling bone marrow grafts had the best outcomes. Conclusions and Relevance: Survival rates have not improved for infants with malignant diseases over the 15-year study period. Infants with nonmalignant diseases had improved survival rates in the earlier but not the later study period. Higher relapses for the malignant cohort and toxicities for all infants remain significant challenges. Strategies to reduce relapse and toxicity and optimize donor and graft selection may improve outcomes in the future.