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During the past decade, the outcomes of pediatric patients with acute myeloid leukemia (AML) have plateaued with 5-year event-free survival (EFS) and overall survival (OS) of approximately 46 and 64%, respectively. Outcomes are particularly poor for those children with high-risk disease, who have 5-year OS of 46%. Substantial survival improvements have been observed for a subset of patients treated with targeted therapies. Specifically, children with KMT2A-rearranged AML and/or FLT3 internal tandem duplication (FLT3-ITD) mutations benefitted from the addition of gemtuzumab ozogamicin, an anti-CD33 antibody-drug conjugate, in the AAML0531 clinical trial (NCT00372593). Sorafenib also improved response and survival in children with FLT3-ITD AML in the AAML1031 clinical trial (NCT01371981). Advances in characterization of prognostic cytomolecular events have helped to identify patients at highest risk of relapse and facilitated allocation to consolidative hematopoietic stem cell transplant (HSCT) in first remission. Some patients clearly have improved survival with HSCT, although the benefit is largely unknown for most patients. Finally, data-driven refinements in supportive care recommendations continue to evolve with meaningful and measurable reductions in toxicity and improvements in EFS and OS. As advances in application of targeted therapies, risk stratification, and improved supportive care measures are incorporated into current trials and become standard-of-care, there is every expectation that we will see improved survival with a reduction in toxic morbidity and mortality. The research agenda of the Children's Oncology Group's Myeloid Diseases Committee continues to build upon experience and outcomes with an overarching goal of curing more children with AML., (© 2023 Wiley Periodicals LLC.)

Bortezomib (BTZ) was recently evaluated in a randomized phase 3 clinical trial by the Children's Oncology Group (COG) that compared standard chemotherapy (cytarabine, daunorubicin, and etoposide [ADE]) vs standard therapy with BTZ (ADEB) for de novo pediatric acute myeloid leukemia (AML). Although the study concluded that BTZ did not improve outcome overall, we examined patient subgroups benefiting from BTZ-containing chemotherapy using proteomic analyses. The proteasome inhibitor BTZ disrupts protein homeostasis and activates cytoprotective heat shock responses. Total heat shock factor 1 (HSF1) and phosphorylated HSF1 (HSF1-pSer326) were measured in leukemic cells from 483 pediatric patients using reverse phase protein arrays. HSF1-pSer326 phosphorylation was significantly lower in pediatric AML compared with CD34+ nonmalignant cells. We identified a strong correlation between HSF1-pSer326 expression and BTZ sensitivity. BTZ significantly improved outcome of patients with low-HSF1-pSer326 with a 5-year event-free survival of 44% (ADE) vs 67% for low-HSF1-pSer326 treated with ADEB (P = .019). To determine the effect of HSF1 expression on BTZ potency in vitro, cell viability with HSF1 gene variants that mimicked phosphorylated (S326A) and nonphosphorylated (S326E) HSF1-pSer326 were examined. Those with increased HSF1 phosphorylation showed clear resistance to BTZ vs those with wild-type or reduced HSF1-phosphorylation. We hypothesize that HSF1-pSer326 expression could identify patients who benefit from BTZ-containing chemotherapy., (© 2021 by The American Society of Hematology.)

Background: Cancer therapy-induced cardiomyopathy (CCM) is associated with cumulative drug exposures and preexisting cardiovascular disorders. These parameters incompletely account for substantial interindividual susceptibility to CCM. We hypothesized that rare variants in cardiomyopathy genes contribute to CCM., Methods: We studied 213 patients with CCM from 3 cohorts: retrospectively recruited adults with diverse cancers (n=99), prospectively phenotyped adults with breast cancer (n=73), and prospectively phenotyped children with acute myeloid leukemia (n=41). Cardiomyopathy genes, including 9 prespecified genes, were sequenced. The prevalence of rare variants was compared between CCM cohorts and The Cancer Genome Atlas participants (n=2053), healthy volunteers (n=445), and an ancestry-matched reference population. Clinical characteristics and outcomes were assessed and stratified by genotypes. A prevalent CCM genotype was modeled in anthracycline-treated mice., Results: CCM was diagnosed 0.4 to 9 years after chemotherapy; 90% of these patients received anthracyclines. Adult patients with CCM had cardiovascular risk factors similar to the US population. Among 9 prioritized genes, patients with CCM had more rare protein-altering variants than comparative cohorts ( P≤1.98e-04). Titin-truncating variants (TTNtvs) predominated, occurring in 7.5% of patients with CCM versus 1.1% of The Cancer Genome Atlas participants ( P=7.36e-08), 0.7% of healthy volunteers ( P=3.42e-06), and 0.6% of the reference population ( P=5.87e-14). Adult patients who had CCM with TTNtvs experienced more heart failure and atrial fibrillation ( P=0.003) and impaired myocardial recovery ( P=0.03) than those without. Consistent with human data, anthracycline-treated TTNtv mice and isolated TTNtv cardiomyocytes showed sustained contractile dysfunction unlike wild-type ( P=0.0004 and P<0.002, respectively)., Conclusions: Unrecognized rare variants in cardiomyopathy-associated genes, particularly TTNtvs, increased the risk for CCM in children and adults, and adverse cardiac events in adults. Genotype, along with cumulative chemotherapy dosage and traditional cardiovascular risk factors, improves the identification of patients who have cancer at highest risk for CCM., Clinical Trial Registration: URL: https://www.clinicaltrials.gov . Unique identifiers: NCT01173341; AAML1031; NCT01371981.

This population analysis described the pharmacokinetics of bortezomib after twice-weekly, repeat-dose, intravenous administration in pediatric patients participating in 2 clinical trials: the phase 2 AALL07P1 (NCT00873093) trial in relapsed acute lymphoblastic leukemia and the phase 3 AAML1031 (NCT01371981) trial in de novo acute myelogenous leukemia. The sources of variability in the pharmacokinetic parameters were characterized and quantified to support dosing recommendations. Patients received intravenous bortezomib 1.3 mg/m 2 twice-weekly, on days 1, 4, and 8 during specific blocks or cycles of both trials and on day 11 of block 1 of study AALL07P1, in combination with multiagent chemotherapy. Blood samples were obtained and the plasma was harvested on day 8 over 0-72 hours postdose to measure bortezomib concentrations by liquid chromatography-tandem mass spectrometry. Concentration-time data were analyzed by nonlinear mixed-effects modeling. Covariates were examined using forward addition (P < .01)/backward elimination (P < .001). Data were included from 104 patients (49%/51% acute lymphoblastic leukemia/acute myelogenous leukemia; 60%/40% aged 2-11 years/12-16 years). Bortezomib pharmacokinetics were described by a 3-compartment model with linear elimination. Body surface area adequately accounted for variability in clearance (exponent 0.97), supporting body surface area-based dosing. Stratified visual predictive check simulations verified that neither age group nor patient population represented sources of meaningful pharmacokinetic heterogeneity not accounted for by the final population pharmacokinetic model. Following administration of 1.3 mg/m 2 intravenous bortezomib doses, body surface area-normalized clearance in pediatric patients was similar to that observed in adult patients, thereby indicating that this dose achieves similar systemic exposures in pediatric patients., (© 2017, The Authors. The Journal of Clinical Pharmacology published by Wiley Periodicals, Inc. on behalf of American College of Clinical Pharmacology.)

Purpose: Gemtuzumab ozogamicin (GO), a calicheamicin-conjugated mAb against CD33, has been used in the treatment of acute myeloid leukemia (AML). We evaluated the impact of the addition of GO to standard chemotherapy and hematopoietic stem cell transplant (HCT) in patients withFLT3/ITD., Experimental Design: We analyzed children withFLT3/ITD-positive AML (n= 183) treated on two consecutive Children's Oncology Group AML trials (NCT00070174andNCT00372593). Outcomes were assessed forFLT3/ITD patients receiving standard chemotherapy with or without GO (GO vs. No-GO, respectively), and the impact of consolidation HCT for high-riskFLT3/ITD patients [highFLT3/ITD allelic ratio (ITD-AR)]., Results: For allFLT3/ITD patients, complete remission (CR) rates for the GO versus No-GO cohorts were identical (64% vs. 64%;P= 0.98). Relapse rate (RR) after initial CR was 37% for GO recipients versus 59% for No-GO recipients (P= 0.02), disease-free survival (DFS) was similar (47% vs. 41%;P= 0.45), with higher treatment-related mortality (TRM) in GO recipients (16% vs. 0%;P= 0.008). Among high-riskFLT3/ITD patients with high ITD-AR, those who received HCT in first CR with prior exposure to GO had a significant reduction in RR (15% vs. 53%;P= 0.007), with a corresponding DFS of 65% versus 40% (P= 0.08), and higher TRM (19% vs. 7%;P= 0.08)., Conclusions: CD33 targeting with HCT consolidation may be an important therapeutic strategy in high-riskFLT3/ITD AML and its efficacy and associated toxicity warrant further investigation., (©2015 American Association for Cancer Research.)

Purpose: CD33 is variably expressed on acute myeloid leukemia (AML) blasts and is targeted by gemtuzumab ozogamicin (GO). GO has shown benefit in both adult and pediatric AML trials, yet limited data exist about whether GO response correlates with CD33 expression level., Patients and Methods: CD33 expression levels were prospectively quantified by multidimensional flow cytometry in 825 patients enrolled in Children's Oncology Group AAML0531 and correlated with response to GO., Results: Patients with low CD33 expression (lowest quartile of expression [Q1]) had no benefit with the addition of GO to conventional chemotherapy (relapse risk [RR]: GO 36% v No-GO 34%, P = .731; event-free survival [EFS]: GO 53% v No-GO 58%, P = .456). However, patients with higher CD33 expression (Q2 to Q4) had significantly reduced RR (GO 32% v No-GO 49%, P < .001) and improved EFS (GO 53% v No-GO 41%, P = .005). This differential effect was observed in all risk groups. Specifically, low-risk (LR), intermediate-risk (IR), and high-risk (HR) patients with low CD33 expression had similar outcomes regardless of GO exposure, whereas the addition of GO to conventional chemotherapy resulted in a significant decrease in RR and disease-free survival (DFS) for patients with higher CD33 expression (LR RR, GO 13% v No-GO 35%, P = .001; LR DFS, GO 79% v No-GO 59%, P = .007; IR RR, GO 44% v No-GO 57%, P = .044; IR DFS, GO 51% v No-GO 40%, P = .078; HR RR, GO 40% v No-GO 73%, P = .016; HR DFS, GO 47% v No-GO 28%, P = .135)., Conclusion: We demonstrate that GO lacks clinical benefit in patients with low CD33 expression but significantly reduces RR and improves EFS in patients with high CD33 expression, which suggests a role for CD33-targeted therapeutics in subsets of pediatric AML., (© 2016 by American Society of Clinical Oncology.)

Background: A better understanding of drivers of treatment costs may help identify effective cost containment strategies and prioritize resources. We aimed to develop a method for estimating inpatient costs for pediatric patients with acute myeloid leukemia (AML) enrolled on NCI-funded Phase III trials, compare costs between AAML0531 treatment arms (standard chemotherapy ± gemtuzumab ozogamicin (GMTZ)), and evaluate primary drivers of costs for newly diagnosed pediatric AML., Procedure: Patients from the AAML0531 trial were matched on hospital, sex, and dates of birth and diagnosis to the Pediatric Health Information Systems (PHIS) database to obtain daily billing data. Inpatient treatment costs were calculated as adjusted charges multiplied by hospital-specific cost-to-charge ratios. Generalized linear models were used to compare costs between treatment arms and courses, and by patient characteristics., Results: Inpatient costs did not differ by randomized treatment arm. Costs varied by course with stem cell transplant being most expensive, followed by Intensification II (cytarabine/mitoxantrone) and Induction I (cytarabine/daunorubicin/etoposide). Room/board and pharmacy were the largest contributors to inpatient treatment cost, representing 74% of the total cost. Higher AML risk group (P = 0.0003) and older age (P < 0.0001) were associated with significantly higher daily inpatient cost., Conclusions: Costs from external data sources can be successfully integrated into NCI-funded Phase III clinical trials. Inpatient treatment costs did not differ by GMTZ exposure but varied by chemotherapy course. Variation in cost by course was driven by differences in duration of hospitalization through room/board charges as well as increased clinical and pharmacy charges in specific courses., (© 2015 Wiley Periodicals, Inc.)

Background: Oncology drug shortage is associated with increased patient adverse events and decreased enrollment on clinical trials for adult patients; however, the impact of oncology drug shortages has not been well studied in children with cancer., Procedure: The Children's Oncology Group (COG) distributed a 5-item survey to 226 COG site-specific principal investigators (PI's) and 14-item survey to 161 COG pharmacists to gather data the impact of chemotherapeutic shortages on clinical trials and patient care., Results: The response rate was 66.4% (150/226) for PI's and 29.8% (48/161) for pharmacists. COG PI's reported daunorubicin (73%), methotrexate (56%), asparaginase/PEG-asparaginase (42%), doxorubicin (26%), thiotepa (21%), and cytarabine (20%) were most commonly in shortage, while COG pharmacists reported daunorubicin (80%), methotrexate (66%), vincristine (21%), thiotepa (41%), asparaginase/PEG-asparaginase (34%), and cytarabine (34%) were most commonly in shortage over the past two years. Pharmacists were twice as likely to report a shortage compared with PI's (OR 2.1, 95% CI: 1.6-2.7, P < 0.0001). Fifty percent (74/147) of COG PI's reported at least one patient enrolled on a clinical trial was impacted by drug shortage, and 66% (98/148) of COG PI's reported at least one patient had clinical care impacted by drug shortage., Conclusions: Chemotherapy shortages remain widespread across institutions, hinder clinical trials, and may contribute to adverse events in children with cancer. The increased frequency of chemotherapy shortages reported by pharmacists suggests that pharmacist efforts may mitigate negative impact chemotherapy shortages. Over half of pediatric institutions are implementing recommendations to address shortages, such as cross-institutional collaboration and center-level guidelines., (© 2015 Wiley Periodicals, Inc.)

Background: Better knowledge of patient and cancer treatment factors associated with nausea/vomiting (NV) in pediatric oncology patients could enhance prophylaxis. We aimed to describe such factors in children receiving treatment for acute myeloid leukemia (AML)., Methods: Retrospective longitudinal cohort study of 1,668 hospitalized children undergoing treatment for AML from the Pediatric Health Information System database (39 hospitals, 1999-2010). Antiemetic alteration, which included switch (a change in prescribed 5-HT₃ receptor antagonists) and rescue (receipt of an adjunct antiemetic), were first validated and then used as surrogates of problematic NV. Logistic and negative binomial regression modeling were used to test whether patient characteristics were associated with problematic NV., Results: Increasing age is associated with greater odds of experiencing antiemetic switch and higher relative rate of antiemetic rescue. Within a treatment cycle, each consecutive inpatient chemotherapy day decreased the likelihood of requiring antiemetic alteration. Each consecutive inpatient-day post-chemotherapy was associated with decreased need for switch, but increased need for rescue. Subsequent cycles of AML therapy were associated with lower odds of antiemetic switch on both chemotherapy and non-chemotherapy days, a lower rate of antiemetic rescue on chemotherapy days, and an increased rate of rescue on non-chemotherapy days., Conclusion: In pediatric patients with AML, increasing age is strongly associated with greater antiemetic alteration. Antiemetic alteration occurs early in treatment overall, and early within each admission. While additional cycles of therapy are associated with less alteration overall, there is persistent rescue in the days after chemotherapy, suggesting additional etiologies of NV in pediatric cancer patients., (© 2014 Wiley Periodicals, Inc.)

Background: Limited data exist on induction mortality of pediatric patients with acute promyelocytic leukemia in the United States, usage of all-trans retinoic acid (ATRA) during acute promyelocytic leukemia induction, and the resources needed to deliver induction therapy., Procedure: Using the Pediatric Health Information System database we established a retrospective cohort of patients treated for newly diagnosed acute promyelocytic leukemia with ATRA between January 1999 and September 2009 in 32 of 43 PHIS contributing free-standing pediatric hospitals in the United States. Standard statistical methods were used to determine in-hospital induction mortality, ATRA administration, and resource utilization during a 60-day observation period., Results: A total of 163 children were identified who met eligibility criteria for cohort inclusion; 52% were female and 76% were white with an average age of 12.7 years. A total of 12 patients (7.4%) died, with 7 (58.3%) dying within the first 7 days of first admission. The mean time to first ATRA exposure increased with decreasing age (P = 0.0016). Resource utilization for management of retinoic acid syndrome was higher than anticipated based on prior studies and differed significantly from patients with non-M3 acute myeloid leukemia., Conclusions: The induction mortality for pediatric acute promyelocytic leukemia remains substantial with wide variation in ATRA administration and high rates of resource utilization., (© 2013 Wiley Periodicals, Inc.)

Background: Acute lymphoblastic (ALL) and myeloid leukemia (AML) account for approximately 26% of pediatric cancers. Anthracyclines are widely used to treat these leukemias, but dosing is limited by cardiotoxicity. Data support the efficacy of dexrazoxane as a cardioprotectant in children; however, dexrazoxane use in children is not universally accepted due to concerns about toxicity, impact on the antitumor effect of anthracyclines, and risk of secondary malignant neoplasms (SMN)., Procedure: We conducted a retrospective cohort study to describe patterns of dexrazoxane use in pediatric patients with ALL or AML using the Pediatric Health Information Systems (PHIS) database. Patients identified as having de novo ALL and AML at these PHIS hospitals were included., Results: Of 8,733 patients with ALL and 2,556 with AML, 207 (2.4%) and 52 (2.0%) received dexrazoxane, respectively. Dexrazoxane use was greater in older children with ALL and AML and in black patients and males with ALL. Dexrazoxane use varied across time and by region in ALL, but not in AML. Prescribing practices differed across institutions and most patients received the first dose early or late after the start of leukemia treatment., Conclusions: Dexrazoxane administration is limited in patients with ALL and AML and prescribing practices vary across the country. Further work is necessary to understand how dexrazoxane is used in patients at highest risk of developing cardiotoxicity and to define its true effect on the development of SMNs., (Copyright © 2012 Wiley Periodicals, Inc.)

Purpose: To determine the toxicity profile, dose-limiting toxicities (DLTs), maximum-tolerated dose (MTD), pharmacokinetics, and pharmacodynamics of cediranib administered orally, once daily, continuously in children and adolescents with solid tumors., Patients and Methods: Children and adolescents with refractory solid tumors, excluding primary brain tumors, were eligible. DLT at the starting dose of 12 mg/m(2)/d resulted in de-escalation to 8 mg/m(2)/d and subsequent re-escalation to 12 and 17 mg/m(2)/d. Pharmacokinetic and pharmacodynamic studies were performed during cycle 1. Response was evaluated using WHO criteria., Results: Sixteen patients (median age, 15 years; range, 8 to 18 years) were evaluable for toxicity. DLTs (grade 3 nausea, vomiting, fatigue in one; hypertension and prolonged corrected QT interval in another) occurred in patients initially enrolled at 12 mg/m(2)/d. Subsequently, 8 mg/m(2)/d was well tolerated in three patients. An additional seven patients were enrolled at 12 mg/m(2)/d; one had DLT (grade 3 diarrhea). At 17 mg/m(2)/d, two of four patients had DLTs (grade 3 nausea; intolerable grade 2 fatigue). Non-dose-limiting toxicities included left ventricular dysfunction, elevated thyroid stimulating hormone, palmar-plantar erythrodysesthesia, weight loss, and headache. The MTD of cediranib was 12 mg/m(2)/d (adult fixed dose equivalent, 20 mg). At 12 mg/m(2)/d, the median area under the plasma concentration-time curve extrapolated to infinity (AUC(0-∞)) was 900 ng·h/mL, which is similar to adults receiving 20 mg. Objective responses were observed in patients with Ewing sarcoma, synovial sarcoma, and osteosarcoma., Conclusion: The recommended monotherapy dose of cediranib for children with extracranial solid tumors is 12 mg/m(2)/d administered orally, once daily, continuously. A phase II study is in development.

Purpose: Identify prognostic factors that influence outcome after unrelated donor bone marrow transplantation in children with acute myeloid leukemia (AML)., Patients and Methods: Included are 268 patients (age

Acute lymphoblastic leukemia is the most common childhood cancer and generally has a favorable prognosis. However, some children experience disease relapse or clinically important treatment-related toxicities. Although some of the risk factors for treatment failure and toxicity are known, these risk factors still imperfectly predict relapse and toxicity. Genetic variation in the enzymes of the folic acid cycle, one-carbon transfer, immune surveillance, drug metabolism and transport may determine some of the variability in treatment response. This review summarizes the present published literature on the role of these genetic polymorphisms in determining treatment response. Despite these recent advances, further work is needed to develop clinically useful genetic predictors of leukemia treatment response.