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NSG mice were injected in the tail with either ETP-ALL (TALL-x-11) or typical T-ALL (TALL-x-2) 1X106 cells and following engraftment to 65% the mice were randomized to receive vehicle, ABT-199 or ABT-263 treatment for two-weeks. The spleen weights (A) and absolute human CD45+ counts (B) along with % human CD45+ cell in the blood (C) were measured for the ETP-ALL primagraft following treatment. The leg bones were harvested and representative images are shown for the different treatments (D). Similar experiments were performed for the typical T-ALL primagraft spleen weights (E), absolute human CD45+ count in the spleen (F) with % human CD45+ cells in the blood were measured (G). Similarly the legs bones were harvested and representative images are shown (H).

Supplementary Table 1 and 2 - PDF file 68K, Supplementary Table 1. Identity of tagSNPs, details of PCR and ASO hybridization Supplementary Table 2. Identity of polymorphisms genotyped only in controls

Purpose: Asparaginase (ASNase) is a standard and critical component in the therapy of childhood acute lymphoblastic leukemia (ALL), but it is also associated with several toxicities.Experimental design: We recently reported the results of an association study between ASNase pathway genes and event-free survival (EFS) in childhood patients with ALL. The same polymorphisms were interrogated here in relation to allergies, pancreatitis, and thrombotic events following treatment with E. coli ASNase.Results: Among patients of the discovery group, allergies, and pancreatitis were more frequent in individuals who are homozygous for the triple-repeat allele (3R) of the asparagine synthetase (ASNS) gene, resulting in remarkably higher risk of these toxicities associated with 3R3R genotype [OR for allergies, 14.6; 95% confidence interval (CI), 3.6–58.7; P < 0.0005 and OR for pancreatitis, 8.6; 95% CI, 2.0–37.3; P = 0.01]. In contrast, the ASNS haplotype *1 harboring double-repeat (2R) allele had protective effect against these adverse reactions (P ≤ 0.01). The same haplotype was previously reported to confer reduction in EFS. The risk effect of 3R3R genotype was not replicated in the validation cohort, whereas the protective effect of haplotype *1 against allergies was maintained (P ≤ 0.002). Analysis with additional polymorphisms in ASNS locus in lymphoblastoid cell lines showed that haplotype *1 is diversified in several subtypes of which one was associated with reduced in vitro sensitivity to ASNase (rs10486009, P = 0.01) possibly explaining an association seen in clinical setting.Conclusions: This finding might have implication for treatment individualization in ALL and other cancers using asparagine depletion strategies. Clin Cancer Res; 21(2); 329–34. ©2014 AACR.See related commentary by Avramis, p. 230

PDF file - 80K, Polymorphisms in ATF5, ASNS and ASS1 genes analyzed in the relation to ASNase related complications.

Purpose: Corticosteroids induce apoptosis in the malignant lymphoid cells and are critical component of combination therapy for acute lymphoblastic leukemia (ALL). Several genome-wide microarray studies showed major implication of proapoptotic Bim in mediating corticosteroid-related resistance in leukemia cells.Experimental Design: We investigated Bim gene polymorphisms and their association with childhood ALL outcome, and the mechanism underlying the observed finding.Results: Lower overall survival (OS) was associated with BimC29201T located in Bcl-2 homology 3 (BH3) domain (P = 0.01). An association remained significant in multivariate model (P = 0.007), was more apparent in high-risk patients (P = 0.004) and patients treated with dexamethasone (P = 0.009), and was subsequently confirmed in the replication patient cohort (P = 0.03). RNA analysis revealed that C29201T affects generation of γ isoforms (γ1) that lack proapoptotic BH3 domain. The phenotypic effect was minor suggesting the influence of additional factors that may act in conjunction with Bim genotype. Combined analysis with Mcl gene polymorphism (G-486T) revealed profound reduction in OS in individuals with both risk genotypes (P < 0.0005 in discovery and P = 0.002 in replication cohort) and particularly in high-risk patients (P ≤ 0.008).Conclusions: Increased expression of prosurvival Mcl1 and presence of Bim isoforms lacking proapoptotic function might explain marked reduction of OS in a disease and dose-dependent manner in ALL patients carrying Bim- and Mcl1-risk genotypes. Clin Cancer Res; 19(18); 5240–9. ©2013 AACR.

PDF file, 62K, Newly acquired unpublished clinical data for cases previously described by our group.

Supplementary Figures 1-2 from Differentiation of NUT Midline Carcinoma by Epigenomic Reprogramming

Supplementary Tables 1-3 from Gene Expression Profiling Identifies BAX-δ as a Novel Tumor Antigen in Acute Lymphoblastic Leukemia

NUT midline carcinoma (NMC) is a lethal pediatric tumor defined by the presence of BRD-NUT fusion proteins that arrest differentiation. Here we explore the mechanisms underlying the ability of BRD4-NUT to prevent squamous differentiation. In both gain-of and loss-of-expression assays, we find that expression of BRD4-NUT is associated with globally decreased histone acetylation and transcriptional repression. Bulk chromatin acetylation can be restored by treatment of NMC cells with histone deacetylase inhibitors (HDACi), engaging a program of squamous differentiation and arrested growth in vitro that closely mimics the effects of siRNA-mediated attenuation of BRD4-NUT expression. The potential therapeutic utility of HDACi differentiation therapy was established in three different NMC xenograft models, where it produced significant growth inhibition and a survival benefit. Based on these results and translational studies performed with patient-derived primary tumor cells, a child with NMC was treated with the FDA-approved HDAC inhibitor, vorinostat. An objective response was obtained after five weeks of therapy, as determined by positron emission tomography. These findings provide preclinical support for trials of HDACi in patients with NMC. Cancer Res; 71(7); 2686–96. ©2011 AACR.

Hispanic children have a higher incidence of acute lymphoblastic leukemia (ALL) and inferior treatment outcomes relative to non-Hispanic White children. We previously reported that Hispanic children with ALL had lower risk of fracture and osteonecrosis. To unravel the genetic root of such ethnic differences, we genotyped 449 patients from the DFCI 05-001 cohort and analyzed their ancestry. Patients with discordant clinical and genetic ancestral groups were reclassified, and those with unknown ancestry were reassigned on the basis of genetic estimates. Both clinical and genetic ancestries were analyzed in relation to risk of bone toxicities and survival outcomes. Consistent with clinically reported race/ethnicity, genetically defined Hispanic and Black patients had significantly lower risk of fracture (Hispanic: subdistribution hazard ratio [SHR], 0.42; 95% confidence interval [CI], 0.22-0.81; P = .01; Black: SHR, 0.28; 95% CI, 0.10-0.75; P = .01), and osteonecrosis (Hispanic: SHR, 0.12; 95% CI, 0.02-0.93; P = .04; Black: SHR, 0.24; 95% CI, 0.08-0.78; P = .02). The lower risk was driven by African but not Native American or Asian ancestry. In addition, patients with a higher percentage of Native American ancestry had significantly poorer overall survival and event-free survival. Our study revealed that the lower risk of bone toxicities among Black and Hispanic children treated for ALL was attributed, in part, to the percentage of African ancestry in their genetic admixture. The findings provide suggestive evidence for the protective effects of genetic factors associated with African decent against bone damage caused by ALL treatment and clues for future studies to identify underlying biological mechanisms.

PURPOSE The benefits and risks of supplementation with antioxidants during cancer therapy have been a controversial area. Few studies have systematically evaluated dietary intake of antioxidants with toxicity and survival in childhood cancer. We sought to determine the role of dietary intake of antioxidants on rates of infections, mucositis, relapse, and disease-free survival during induction and postinduction phases of therapy among children and adolescents with acute lymphoblastic leukemia (ALL). PATIENTS AND METHODS We enrolled 794 children in a prospective clinical trial for treatment of ALL. Dietary intake was prospectively evaluated by a food frequency questionnaire. The association between dietary intake of antioxidants and treatment-related toxicities and survival were evaluated with the Benjamini-Hochberg false discovery rate (q) and logistic regression and the Kaplan-Meier method, respectively. RESULTS Dietary surveys were available for analysis from 614 (77%), and 561 (71%) participants at diagnosis and at end of induction, respectively. Of 513 participants who completed the dietary surveys at both time points, 120 (23%) and 87 (16%) experienced a bacterial infection and 22 (4%) and 55 (10%) experienced mucositis during the induction or postinduction phases of treatment, respectively. Increased intake of dietary antioxidants was associated with significantly lower rates of infection and mucositis. No association with relapse or disease-free survival was observed. Supplementation was not associated with toxicity, relapse, or survival. CONCLUSION Consumption of antioxidants through dietary intake was associated with reduced rates of infection or mucositis, with no increased risk of relapse or reduced survival. Dietary counseling on a well-balanced diet that includes an array of antioxidants from food sources alone may confer a benefit from infections and mucositis during treatment of childhood ALL.

Although thromboembolism (TE) is a serious complication in patients with acute lymphoblastic leukemia (ALL), thromboprophylaxis is not commonly used due to the inherent bleeding risk in this population. Identifying prothrombotic risk factors will help target thromboprophylaxis to those at highest thrombotic risk. We aimed to define predictors and the impact of TE on ALL outcome in children (1-18 years) treated on the Dana-Farber Cancer Institute ALL 05-001 trial.Clinical and laboratory data including TE events were prospectively collected. PCR-based allelic discrimination assay identified single-nucleotide polymorphisms (SNP) for prothrombin G20210A (rs1799963) and Factor V G1691A (rs6025). Univariate and multivariable competing risk regression models evaluated the effect of diagnostic clinical (age, sex, body mass index, ALL-immunophenotype, risk group) and laboratory variables (presenting leukocyte count, blood group, SNPs) on the cumulative incidence of TE. Cox regression modeling explored the impact of TE on survival.Of 794 patients [median age 4.97 (range, 1.04-17.96) years; males 441], 100 developed TE; 25-month cumulative incidence 13.0% (95% CI, 10.7%-15.5%). Univariate analyses identified older age (≥10 years), presenting leucocyte count, T-ALL, high-risk ALL, and non-O blood group as risk factors. Age and non-O blood group were independent predictors of TE on multivariable regression; the blood group impact being most evident in patients 1-5 years of age (P = 0.011). TE did not impact survival. Induction TE was independently associated with induction failure (OR 6.45; 95% CI, 1.64-25.47; P = 0.008).We recommend further evaluation of these risk factors and consideration of thromboprophylaxis for patients ≥10 years (especially those ≥15 years) when receiving asparaginase.

Aim: To evaluate top-ranking genes identified through genome-wide association studies for an association with corticosteroid-related osteonecrosis in children with acute lymphoblastic leukemia (ALL) who received Dana–Farber Cancer Institute treatment protocols. Patients & methods: Lead SNPs from these studies, as well as other variants in the same genes, pooled from whole exome sequencing data, were analyzed for an association with osteonecrosis in childhood ALL patients from Quebec cohort. Top-ranking variants were verified in the replication patient group. Results: The analyses of variants in the ACP1-SH3YL1 locus derived from whole exome sequencing data showed an association of several correlated SNPs (rs11553746, rs2290911, rs7595075, rs2306060 and rs79716074). The rs79716074 defines *B haplotype of the APC1 gene, which is well known for its functional role. Conclusion: This study confirms implication of the ACP1 gene in the treatment-related osteonecrosis in childhood ALL and identifies novel, potentially causal variant of this complication.

PURPOSE Dana-Farber Cancer Institute Acute Lymphoblastic Leukemia (ALL) Consortium Protocol 11-001 assessed efficacy and toxicity of calaspargase pegol (calaspargase), a novel pegylated asparaginase formulation with longer half-life, compared with the standard formulation pegaspargase. METHODS Patients age 1 to ≤ 21 years with newly diagnosed ALL or lymphoblastic lymphoma were randomly assigned to intravenous pegaspargase or calaspargase, 2,500 IU/m2/dose. Patients received one induction dose. Beginning week 7, pegaspargase was administered every 2 week for 15 doses and calaspargase every 3 week for 10 doses (30 weeks). Serum asparaginase activity (SAA) (≥ 0.1 IU/mL considered therapeutic) was assessed 4, 11, 18, and 25 days after the induction dose and before each postinduction dose. RESULTS Between 2012 and 2015, 239 eligible patients enrolled (230 ALL, nine lymphoblastic lymphoma); 120 were assigned to pegaspargase and 119 to calaspargase. After the induction dose, SAA was ≥ 0.1 IU/mL in ≥ 95% of patients on both arms 18 days after dosing. At day 25, more patients had SAA ≥ 0.1 IU/mL with calaspargase (88% v 17%; P ˂ .001). Postinduction, median nadir SAAs were similar (≥ 1.0 IU/mL) for both arms. Of 230 evaluable patients, 99% of pegaspargase and 95% of calaspargase patients achieved complete remission ( P = .12), with no difference in frequency of high end-induction minimal residual disease among evaluable patients with B acute lymphoblastic leukemia (B-ALL). There were no differences in frequencies of asparaginase allergy, pancreatitis, thrombosis, or hyperbilirubinemia. With 5.3 years median follow-up, 5-year event-free survival for pegaspargase was 84.9% (SE ± 3.4%) and 88.1% (± SE 3.0%) for calaspargase ( P = .65). CONCLUSION Every 3-week calaspargase had similar nadir SAA, toxicity, and survival outcomes compared with every 2-week pegaspargase. The high nadir SAA observed for both preparations suggest dosing strategies can be further optimized.

Childhood cancer survival rates have drastically improved over the past few decades. Unfortunately this population experiences a significantly increased risk of excess morbidity and early mortality, of which cardiotoxicity is among the leading causes. Cardiotoxicity may present acutely during treatment or decades after completion of therapy and includes disease states such as congestive heart failure, hypertension, and early cardiac death. A multitude of both therapy-related and non-modifiable risk factors contribute to the development of cardiotoxicity. Treatments with anthracyclines, radiation, and targeted therapies such as VEGF inhibitors put patients at particularly increased risk. Screening for and identifying survivors at risk of cardiotoxicity is extremely important. Utilizing preventive measures such as the cardioprotective medication dexrazoxane with anthracyclines and reducing radiation exposure when feasible can avoid cardiotoxicity among patients; however, no specific therapies for treatment have been standardized for those who do develop adverse cardiac effects. Fortunately the number of childhood cancer survivors will continue to grow. It is therefore essential that research in the prevention of and treatment for cardiotoxicity continues and is at the forefront of discovery.

BACKGROUND/OBJECTIVES While outcomes for pediatric T-cell acute lymphoblastic leukemia (T-ALL) are favorable, there are few widely accepted prognostic factors, limiting the ability to risk stratify therapy. DESIGN/METHODS Dana-Farber Cancer Institute (DFCI) Protocols 05-001 and 11-001 enrolled pediatric patients with newly diagnosed B- or T-ALL from 2005 to 2011 and from 2012 to 2015, respectively. Protocol therapy was nearly identical for patients with T-ALL (N = 123), who were all initially assigned to the high-risk arm. End-induction minimal residual disease (MRD) was assessed by reverse transcription polymerase chain reaction (RT-PCR) or next-generation sequencing (NGS), but was not used to modify postinduction therapy. Early T-cell precursor (ETP) status was determined by flow cytometry. Cases with sufficient diagnostic DNA were retrospectively evaluated by targeted NGS of known genetic drivers of T-ALL, including Notch, PI3K, and Ras pathway genes. RESULTS The 5-year event-free survival (EFS) and overall survival (OS) for patients with T-ALL was 81% (95% CI, 73-87%) and 90% (95% CI, 83-94%), respectively. ETP phenotype was associated with failure to achieve complete remission, but not with inferior OS. Low end-induction MRD (

Aim: To evaluate the association between human leukocyte antigen (HLA) alleles and native Escherichia coli asparaginase hypersensitivity (AH) in children with acute lymphoblastic leukemia (ALL) who received Dana-Farber Cancer Institute treatment protocols. Patients & methods: HLA-DQA1, HLA-DRB1 and HLA-DQB1 alleles were retrieved from available whole exome sequencing data of a subset of childhood ALL patients from Quebec ALL cohort and analyzed for an association with AH. PCR assay was developed to analyze associated alleles in the entire discovery and replication cohorts. Results: Two alleles in linkage disequilibrium ( HLA-DRB1*07:01 and DQA1*02:01) were associated with AH. Additional analyses, performed to distinguish between HLA-DRB1*07:01 haplotypes with and without DQB1*02:02 allele, showed that the association was dependent on the presence of DQB1*02:02. Conclusion: This study confirms the implication of HLA-DRB1*07:01, DQA1*02:01 and DQB1*02:02 alleles in developing AH in childhood ALL.

Health-related quality of life (HRQL) improved progressively during therapy and beyond in children treated for acute lymphoblastic leukemia on the Dana-Farber Cancer Institute (DFCI) 95-01 protocol. This study aimed to validate that trajectory in a successor study (DFCI 00-01) and to compare the HRQL of patients in the 2 studies. Children aged above 5 years were assessed during each phase of treatment (N=4) and 2 years after completion of therapy. Health status and HRQL were measured using Health Utilities Index (HUI) instruments, HUI2 and HUI3. Quality-adjusted life years (QALYs) were calculated and compared with the general population, and patients treated on DFCI 95-01. Over 5 intervals and 758 HUI assessments, mean HRQL increased progressively from remission induction to the time after treatment (P

The role of Hedgehog signaling in normal and malignant T-cell development is controversial. Recently, Hedgehog pathway mutations have been described in T-ALL, but whether mutational activation of Hedgehog signaling drives T-cell transformation is unknown, hindering the rationale for therapeutic intervention. Here, we show that Hedgehog pathway mutations predict chemotherapy resistance in human T-ALL, and drive oncogenic transformation in a zebrafish model of the disease. We found Hedgehog pathway mutations in 16% of 109 childhood T-ALL cases, most commonly affecting its negative regulator PTCH1. Hedgehog mutations were associated with resistance to induction chemotherapy (P = 0.009). Transduction of wild-type PTCH1 into PTCH1-mutant T-ALL cells induced apoptosis (P = 0.005), a phenotype that was reversed by downstream Hedgehog pathway activation (P = 0.007). Transduction of most mutant PTCH1, SUFU, and GLI alleles into mammalian cells induced aberrant regulation of Hedgehog signaling, indicating that these mutations are pathogenic. Using a CRISPR/Cas9 system for lineage-restricted gene disruption in transgenic zebrafish, we found that ptch1 mutations accelerated the onset of notch1-induced T-ALL (P = 0.0001), and pharmacologic Hedgehog pathway inhibition had therapeutic activity. Thus, Hedgehog-activating mutations are driver oncogenic alterations in high-risk T-ALL, providing a molecular rationale for targeted therapy in this disease.

Mitochondrial apoptotic priming predicts response to cancer chemotherapy, but the mechanisms underlying variability in this mitochondrial phenotype among closely related tumors are poorly understood. Ariës et al. show that PRC2 loss-of-function mutations induce resistance to mitochondrial apoptosis in T-ALL., The tendency of mitochondria to undergo or resist BCL2-controlled apoptosis (so-called mitochondrial priming) is a powerful predictor of response to cytotoxic chemotherapy. Fully exploiting this finding will require unraveling the molecular genetics underlying phenotypic variability in mitochondrial priming. Here, we report that mitochondrial apoptosis resistance in T cell acute lymphoblastic leukemia (T-ALL) is mediated by inactivation of polycomb repressive complex 2 (PRC2). In T-ALL clinical specimens, loss-of-function mutations of PRC2 core components (EZH2, EED, or SUZ12) were associated with mitochondrial apoptosis resistance. In T-ALL cells, PRC2 depletion induced resistance to apoptosis induction by multiple chemotherapeutics with distinct mechanisms of action. PRC2 loss induced apoptosis resistance via transcriptional up-regulation of the LIM domain transcription factor CRIP2 and downstream up-regulation of the mitochondrial chaperone TRAP1. These findings demonstrate the importance of mitochondrial apoptotic priming as a prognostic factor in T-ALL and implicate mitochondrial chaperone function as a molecular determinant of chemotherapy response.

Introduction: Increased toxicity with pegaspargase (PEG) in older and higher body mass index (BMI) patients (pts) with acute lymphoblastic leukemia (ALL) has recently led to dose capping practices. We assessed the influence of age, body surface area (BSA), and BMI on PEG-related toxicity and pharmacokinetics from two consecutive DFCI ALL Consortium trials without dose capping. Methods: Patient (pts) aged 1 to 0.1 IU/mL, was assessed 4, 11, 18, and 25 days after the Induction dose and nadir SAA was assessed before each Post-Induction dose. Asparaginase-related toxicities were prospectively assessed and graded by CTCAE version 3.0 (DFCI 05-001) or 4.0 (DFCI 11-001). Asparaginase toxicity for this analysis was defined as ≥1 of the following: pancreatitis, thrombosis, ≥grade 4 hyperbilirubinemia, ≥grade 4 hypertriglyceridemia. Allergy was analyzed separately (due to presumed dose independence). Height and weight at diagnosis were used for analyses. BMI categories were assigned using standard percentile ranges based on gender specific 2000 CDC growth charts. BSA was calculated using the Mosteller formula. Univariate analyses evaluated the relationship of age, BMI, and BSA with asparaginase toxicity. Comparisons of toxicity across BMI and BSA categories were performed using a Jonckheere-Terpstra test. Categorical comparisons for dichotomized BMI and BSA utilized a Fisher's exact test or chi square test. The relationships between BMI and BSA with toxicity were explored using multivariable models. Results: Between 4/2005-12/2011 802 pts enrolled on DFCI 05-001 and between 6/2012-6/2015 240 pts enrolled on DFCI 11-001. Both trials included random assignment of asparaginase formulation. In total 911 patients received pegaspargase during Induction and 351 during Post-Induction. During Induction, pts ≥15 years of age had higher asparaginase toxicity rates (17.1% vs 6.2%, p=0.0003) (Figure 1a). Toxicity differed significantly across BSA categories ( Post-Induction, age ≥15 years was associated with increased asparaginase toxicity (57.1% vs 21%, p Post-Induction, median nadir SAA levels were ≥0.1IU/mL for all BSA and age categories. Median SAA was similar or lower at all time-points for those ≥15 years of age compared with younger children. Median SAA for pts with BSA ≥1.5m 2 were similar or lower compared to those with BSA Conclusion: Age ≥15 years and BSA ≥2m 2 were each associated with significantly increased asparaginase toxicity. Older patients and those with higher BSA had similar or lower median SAA levels at all time-points. These results suggest that the differential toxicity seen in older patients and those with higher BSA is not explained by these patients having higher SAA levels. Prospective exploration of interventions to decrease toxicity in older patients and those with high BSA are needed. Figure 1 Figure 1. Disclosures Neuberg: Madrigal Pharmaceuticals: Other: Stock ownership; Pharmacyclics: Research Funding. Silverman: Takeda, Servier, Syndax, Jazz Pharmaceuticals: Current equity holder in publicly-traded company, Membership on an entity's Board of Directors or advisory committees.

Osteonecrosis (ON) is corticosteroid-related complication, reported in children with acute lymphoblastic leukemia (ALL). We have previously found that polymorphisms in BCL2L11 gene coding for pro-apoptotic Bim protein influence reduction of overall survival (OS) in a corticosteroid (CS) dose-dependent manner in childhood ALL patients. The same set of SNPs was here investigated for an association with CS-related ON assessed retrospectively in 304 children with ALL from Quebec (QcALL cohort) who received Dana-Farber Cancer Institute (DFCI) ALL treatment protocols. Two-year cumulative incidence of symptomatic ON was 10.6%. Two BCL2L11 polymorphisms, the 891T>G (rs2241843) in all QcALL patients and 29201C>T (rs724710) in high-risk group were significantly associated with ON, P = 0.009 and P = 0.003, respectively. The association remained significant in multivariate model (HR891TT = 2.4, 95% CI 1.2–4.8, P = 0.01 and HR29201CC = 5.7, 95% CI 1.6–20.9, P = 0.008). Both polymorphisms influenced viability of dexamethasone treated lymphoblastoid cell lines (P ≤ 0.03). The 891T>G influenced Bim gamma isoform levels (0.03) and its association with ON was also confirmed in replication DFCI cohort (N = 168, P = 0.03). QcALL children had a high incidence of ON during therapy, which was highly associated with BCL2L11 polymorphisms.

Introduction: Hypersensitivity reactions with asparaginase occur frequently in pediatric patients (pts) with acute lymphoblastic leukemia (ALL). The standard approach for pts with reaction to E.coli-derived asparaginase is to switch to Erwinia asparaginase, given concern that clinical reactions reflect presence of neutralizing antibodies; however, Erwinia requires more frequent dosing and is often unavailable. Therapeutic drug monitoring allows for discrimination between pts with pegaspargase hypersensitivity who have sub-therapeutic asparaginase activity and those still able to derive therapeutic benefit from pegaspargase. We prospectively piloted re-challenging pts with pegaspargase after initial Grade 2 hypersensitivity to this agent, with premedication at re-challenge and assessment of serum asparaginase activity (SAA). Methods: Pts aged 1 to < 22 years with newly diagnosed ALL were eligible for DFCI 16-001. Pts received 1 dose of intravenous pegaspargase during Induction, and every 2 weeks for 15 total doses in Post-Induction phases, without routine premedication. Pts were monitored during/after pegaspargase for allergy, with CTCAE version 4.0 event grading. Those with ≥Grade 3 allergy discontinued pegaspargase and were switched to Erwinia. Those with Grade 2 allergic reaction were eligible for pegaspargase re-challenge with pre-medication (acetaminophen, diphenhydramine, and hydrocortisone, or per institutional standard) and slower infusion rate. If < 50% of the intended dose had been administered when reaction occurred, re-challenge was within 1-7 days of initial reaction. If ≥ 50% of the intended dose had been given, re-challenge was at next planned pegaspargase dose. SAA was measured 1-hour, 7-days, and 14-days after the re-challenge infusion (if dose completed). If 1-hour or 7-day level ≥ 0.1 IU/mL, and 14-day level ≥ 0.025 IU/mL, SAA was considered adequate, and the pt continued to receive pegaspargase with premedication. Pts with an inadequate SAA level, or with new ≥ Grade 2 allergic reaction with the re-challenge dose were considered to have failed re-challenge and were changed to Erwinia (or enrolled on a clinical trial of recombinant crisantaspase, an alternative Erwinia preparation). Results: Between 3/2017- 7/2020, 317 eligible pts enrolled. Overall, 81 of 299 (27%) total evaluable pts experienced a first allergic reaction to pegaspargase, 68 pts with Grade 2 reaction, 13 with Grade ≥3. During Induction, 17 of 299 (6%) evaluable pts had allergic reaction to pegaspargase; all Grade 2. Of the 17 Grade 2 reactions, 13 pts (76%) underwent re-challenge in Induction, 9 (69%) re-challenges successful and 4 failed. Post-Induction, 64 of 241 evaluable pts (27%) had a first allergic reaction; 51 Grade 2 and 13 Grade ≥3. Thirty-six of 51 (71%) pts with Grade 2 allergy during Post-Induction underwent re-challenge, as did 1 additional pt with allergy during Induction who was re-challenged with first Post-Induction pegaspargase dose (per protocol guideline, due to receiving ≥50% of Induction dose). Among these re-challenges, 16 were successful, 21 failed. Overall, 25 of 50 (50%) pts who were re-challenged after Grade 2 reaction had a successful challenge and were able to continue pegaspargase. Among the 25 pts with failed re-challenge, 6 pts (24%) had inadequate SAA alone as cause of failure, 17 pts (68%) had an allergic reaction with the re-challenge dose, and 2 (8%) additional patients had both allergic reaction and documented inadequate SAA. Three pts who were successfully re-challenged had a subsequent allergic reaction to pegaspargase. Among the 22 pts who experienced another allergic reaction with pegaspargase (at re-challenge or subsequent dose), 19 pts (86%) experienced Grade 2, and 3 pts experienced Grade 3 reaction. Conclusion: Fifty percent of pts with a Grade 2 reaction to pegaspargase were able to tolerate and achieve adequate SAA when re-challenged with premedication. For those who did react with or after re-challenge, reactions were not more severe. The re-challenge approach limits premedication exposure only to a minority of pts with a history of prior reaction and substantially decreases the number of pts needing to switch to Erwinia asparaginase, which can be challenging to deliver due to administration schedule and drug shortage. Disclosures Place: Novartis: Consultancy, Other: Institutional Research Funding; AbbVie: Consultancy. Silverman:Takeda: Other: advisory board; Servier: Other: advisory board; Syndax: Other: advisory board.

BackgroundNUT midline carcinoma, renamed NUT carcinoma (NC), is an aggressive squamous cancer defined by rearrangement of the NUTM1 gene. Although a subset of patients can be cured, for the majority of patients the prognosis is grim. We sought to classify patients into risk groups based on molecular and clinicopathologic factors at the time of diagnosis.MethodsClinicopathologic variables and survival outcomes were extracted for a total of 141 NC patients from the NUT midline carcinoma Registry using questionnaires and medical records. Translocation type was identified by molecular analyses. Survival tree regression analysis was performed to determine risk factors associated with overall survival (OS).ResultsFor 141 patients, the median age at diagnosis was 23.6 years. Fifty-one percent had thoracic origin compared with 49% nonthoracic sites (41% head and neck, 6% bone or soft tissue, 1% other). The median OS was 6.5 months (95% confidence interval [CI] = 5.8 to 9.1 months). Most patients had the BRD4-NUTM1 fusion (78%), followed by BRD3-NUTM1 (15%) and NSD3-NUTM1 (6%). Survival tree regression identified three statistically distinct risk groups among 124 patients classified by anatomical site and genetics: group A is nonthoracic primary, BRD3-, or NSD3-NUT (n = 12, median OS = 36.5 months, 95% CI = 12.5 to not reported months); group B is nonthoracic primary, BRD4-NUT (n = 45, median OS = 10 months, 95% CI = 7 to 14.6 months); and group C is thoracic primary (n = 67, median OS = 4.4 months, 95% CI = 3.5 to 5.6 months). Only groups A and B had long-term (≥3 years, n = 12) survivors.ConclusionsWe identify three risk groups defined by anatomic site and NUT fusion type. Nonthoracic primary with non-BRD4-NUT fusion confers the best prognosis, followed by nonthoracic primary with BRD4-NUT. Thoracic NC patients, regardless of the NUT fusion, have the worst survival.

Acute lymphoblastic leukemia (ALL) is the most common pediatric malignancy. Nutritional morbidities are a persistent problem facing pediatric patients during and after treatment and age-gender groups that are at risk for nutritional conditions have not been clearly identified. Therapy is a contributing factor; however, the role of dietary intake remains largely unknown. Prior to conduct of interventional trials, an understanding of the effects of treatment on fluctuations in dietary intake is necessary.We enrolled 794 children with ALL in a prospective clinical trial. Dietary intake was collected with a food frequency questionnaire at diagnosis and throughout the course of treatment for pediatric ALL. Reported values were compared to the Dietary Recommended Intake (DRI), and normative values (NHANES). Hierarchical linear models and multilevel mixed-effects ordered logistic regression models were used to evaluate longitudinal changes in dietary intake; independent samples t-test with Bonferroni correction was performed to compare to NHANES.Of the evaluable participants at each timepoint, dietary intake was obtained on 81% (n = 640), 74% (n = 580) and 74% (n = 558) at diagnosis, end of induction phase of treatment, and continuation, respectively. Despite exposure to corticosteroids, caloric intake decreased over therapy for most age-gender groups. Predictive models of excess intake found reduced odds of over-consuming calories (OR 0.738, P 0.05); however, increased odds of over-consuming fat (OR 6.971, P 0.001). When compared to NHANES, we consistently found that ≥1/3 of children were consuming calories in excess of normative values. For select micronutrients, a small proportion of participants were above or below the DRI at each time evaluated.Our study suggests that dietary intake fluctuates during treatment for ALL as compared to age-gender recommended and normative values. Improving our understanding of nutrient fluctuations and dietary quality will facilitate subsequent analyses addressing relationships of dietary intake, toxicity, and survival.

The B/T subtype of mixed phenotype acute leukemia (B/T MPAL) is defined by co-expression of antigens of both B- and T-cell lineages on leukemic blasts. Although it has been suggested that multilineage antigen expression portends poor response to chemotherapy, the clinical characteristics and driver mutations that underlie the pathogenesis of this rare subtype of acute leukemia are scarcely known. We identified nine cases of B/T MPAL from multiple institutions and correlated clinical and immunophenotypic findings with next-generation sequencing data. We report that B/T MPAL commonly presents with lymphadenopathy in adolescence and young adulthood. While the tumors have diverse cytogenetic and genomic perturbations, recurrent acquired aberrations include mutations in the putative transcriptional regulator PHF6 and the JAK-STAT and Ras signaling pathways. Alterations were also identified in genes encoding hematopoietic transcription factors, cell cycle regulators/tumor suppressors, and chromatin modifying enzymes. The genomic landscape of B/T MPAL strongly resembles that of T-ALL subgroups associated with early developmental arrest, while genetic alterations that are common in B-ALL were rarely seen. Two-thirds of the patients responded to ALL-based chemotherapy with or without stem cell transplantation. Our observations lay the groundwork for further study of the unique biology and clinical trajectory of B/T MPAL.

BACKGROUND Children and adolescents with Down syndrome (DS) and acute lymphoblastic leukemia (ALL) are reported to have increased relapse rates and therapy-related mortality (TRM). Treatment regimens for DS-ALL patients often include therapy modifications. Dana-Farber Cancer Institute (DFCI) ALL Consortium protocols have used same risk-stratified treatment for patients with and without DS. PROCEDURES We compared clinical and outcome data of DS (n = 38) and non-DS (n = 1,248) patients enrolled on two consecutive DFCI ALL trials 00-001 (2000-2004) and 05-001 (2005-2011) with similar risk adapted therapy regardless of DS status. RESULTS There was no difference in demographic or presenting clinical features between two groups except absence of T-cell phenotype and lower frequency of hyperdiploidy in DS-ALL group. All DS-ALL patients achieved complete remission; four relapsed and one subsequently died. There was no TRM in DS-ALL patients. DS-ALL patients had significantly higher rates of mucositis (52% vs. 12%, p

For adults with Philadelphia chromosome-negative (Ph-) acute lymphoblastic leukemia (ALL) in first complete remission (CR1), allogeneic hematopoietic cell transplantation (HCT) is an established curative strategy. However, pediatric-inspired chemotherapy may also offer durable leukemia-free survival in the absence of HCT. We compared 422 HCT recipients aged 18-50 years with Ph-ALL in CR1 reported to the CIBMTR with an age-matched concurrent cohort of 108 Ph- ALL CR1 patients who received a Dana-Farber Consortium pediatric-inspired non-HCT regimen. At 4 years of follow-up, incidence of relapse after HCT was 24% (95% CI 19-28) versus 23% (95% CI 15-32) for the non-HCT (chemo) cohort (P=0.97). Treatment-related mortality (TRM) was higher in the HCT cohort [HCT 37% (95% CI 31-42) versus chemo 6% (95% CI 3-12), P

BACKGROUND Impaired cardiac function in doxorubicin-treated childhood cancer survivors is partly mediated by the disruption of mitochondrial energy production. Doxorubicin intercalates into mitochondrial DNA (mtDNA) and disrupts genes encoding for polypeptides that make adenosine triphosphate. METHODS This cross-sectional study examined mtDNA copy numbers per cell and oxidative phosphorylation (OXPHOS) in peripheral blood mononuclear cells (PBMCs) in 64 childhood survivors of high-risk acute lymphoblastic leukemia (ALL) who had been treated on Dana-Farber Cancer Institute childhood ALL protocols and had received doxorubicin alone (42%) or doxorubicin with the cardioprotectant dexrazoxane (58%). The number of mtDNA copies per cell and the OXPHOS enzyme activity of nicotinamide adenine dinucleotide dehydrogenase (complex I [CI]) and cytochrome c oxidase (complex IV [CIV]) were measured with quantitative real-time polymerase chain reaction immunoassays and thin-layer chromatography, respectively. RESULTS At a median follow-up of 7.8 years after treatment, the median number of mtDNA copies per cell for patients treated with doxorubicin alone (1106.3) was significantly higher than the median number for those who had also received dexrazoxane (310.5; P = .001). No significant differences were detected between the groups for CI or CIV activity. CONCLUSIONS Doxorubicin-treated survivors had an increased number of PBMC mtDNA copies per cell, and concomitant use of dexrazoxane was associated with a lower number of mtDNA copies per cell. Because of a possible compensatory increase in mtDNA copies per cell to maintain mitochondrial function in the setting of mitochondrial dysfunction, overall OXPHOS activity was not different between the groups. The long-term sustainability of this compensatory response in these survivors at risk for cardiac dysfunction over their lifespan is concerning. Cancer 2016;122:946–53. © 2016 American Cancer Society.

Summary Background l-asparaginase is a universal component of treatment for childhood acute lymphoblastic leukaemia, and is usually administered intramuscularly. Pegylated Escherichia coli asparaginase (PEG-asparaginase) has a longer half-life and is potentially less immunogenic than the native Escherichia coli ( E coli ) preparation, and can be more feasibly administered intravenously. The aim of the Dana-Farber Cancer Institute Acute Lymphoblastic Leukaemia Consortium Protocol 05-001 (DFCI 05-001) was to compare the relative toxicity and efficacy of intravenous PEG-asparaginase and intramuscular native E coli l-asparaginase in children with newly diagnosed acute lymphoblastic leukaemia. Methods DFCI 05-001 enrolled patients aged 1–18 years with newly diagnosed acute lymphoblastic leukaemia from 11 consortium sites in the USA and Canada. Patients were assigned to an initial risk group on the basis of their baseline characteristics and then underwent 32 days of induction therapy. Those who achieved complete remission after induction therapy were assigned to a final risk group and were eligible to participate in a randomised comparison of intravenous PEG-asparaginase (15 doses of 2500 IU/m 2 every 2 weeks) or intramuscular native E coli l-asparaginase (30 doses of 25 000 IU/m 2 weekly), beginning at week 7 after study entry. Randomisation (1:1) was unmasked, and was done by a statistician-generated allocation sequence using a permuted blocks algorithm (block size of 4), stratified by final risk group. The primary endpoint of the randomised comparison was the overall frequency of asparaginase-related toxicities (defined as allergy, pancreatitis, and thrombotic or bleeding complications). Predefined secondary endpoints were disease-free survival, serum asparaginase activity, and quality of life during therapy as assessed by PedsQL surveys. All analyses were done by intention to treat. This study is registered with ClinicalTrials.gov, number NCT00400946. Findings Between April 22, 2005, and Feb 12, 2010, 551 eligible patients were enrolled. 526 patients achieved complete remission after induction, of whom 463 were randomly assigned to receive intramuscular native E coli l-asparaginase (n=231) or intravenous PEG-asparaginase (n=232). The two treatment groups did not differ significantly in the overall frequency of asparaginase-related toxicities (65 [28%] of 232 patients in the intravenous PEG-asparaginase group vs 59 [26%] of 231 patients in the intramuscular native E coli l-asparaginase group, p=0·60), or in the individual frequency of allergy (p=0·36), pancreatitis (p=0·55), or thrombotic or bleeding complications (p=0·26). Median follow-up was 6·0 years (IQR 5·0–7·1). 5-year disease-free survival was 90% (95% CI 86–94) for patients assigned to intravenous PEG-asparaginase and 89% (85–93) for those assigned to intramuscular native E coli l-asparaginase (p=0·58). The median nadir serum asparaginase activity was significantly higher in patients who received intravenous PEG-asparaginase than in those who received intramuscular native E coli l-asparaginase. Significantly more anxiety was reported by both patients and parent-proxy in the intramuscular native E coli l-asparaginase group than in the intravenous PEG-asparaginase group. Scores for other domains were similar between the groups. The most common grade 3 or worse adverse events were bacterial or fungal infections (47 [20%] of 232 in the intravenous PEG-asparaginase group vs 51 [22%] of 231 patients in the intramuscular E coli l-asparaginase group) and asparaginase-related allergic reactions (14 [6%] vs 6 [3%]). Interpretation Intravenous PEG-asparaginase was not more toxic than, was similarly efficacious to, and was associated with decreased anxiety compared with intramuscular native E coli l-asparaginase, supporting its use as the front-line asparaginase preparation in children with newly diagnosed acute lymphoblastic leukaemia. Funding National Cancer Institute and Enzon Pharmaceuticals.

Cardiotoxicity related to doxorubicin chemotherapy is a major late effect in childhood cancer survivors. Serum cardiac troponin concentrations (cTnT) can be elevated during doxorubicin therapy but the cellular associations with this myocardial injury are not well understood. We evaluate a novel nanotechnology-based biomarker discovery approach on a pilot set of serial serum samples from 11 children with acute lymphoblastic leukemia receiving doxorubicin therapy to determine if a proteomic signature of myocardial injury could be identified. This nanoparticle-based biomarker capture technology was utilized to analyze 40 serial serum samples from these children, 3 of whom seroconverted, 2 from cTnT-negative to cTnT-positive and 1 from cTnT-positive to cTnT-negative. High-resolution mass spectrometry analysis of the captured material identified 13 differentially expressed candidate proteins, whose spectral count values reflected changes in cTnT concentrations, which were verified in the serum samples from the 3 consistently cTnT-negative and 5 consistently cTnT-positive children. Of the 13 candidate proteins, 5 were significantly elevated (p Significance Identification of new biomarkers for early detection of chemotherapy-induced cardiotoxicity is of critical importance so that administration of cardioprotectants can be utilized before substantial heart damage has occurred. We developed and utilized a unique biomarker workflow based on a novel nanotechnology method in order to demonstrate the potential for such an approach to uncover low abundance markers that could be useful in a clinical setting once extensively validated.

Supplemental Digital Content is available in the text., Background: Epidemiologic studies worldwide have provided substantial evidence of the contributions of environmental exposures to the development of childhood cancer, yet this knowledge has not been integrated into the routine practice of clinicians who care for children with this disease. To identify the basis of this deficit, we sought to assess the environmental history-taking behavior and perceptions of environmental health among pediatric hematologists and oncologists. Procedure: A web-based survey was sent from June to October 2012 to 427 pediatric oncologists, fellows, and nurse practitioners from 20 US institutions, with an overall response rate of 45%. Results: Survey responses indicated that environmental exposures are of concern to clinicians. The vast majority of respondents (88%) reported receiving questions from families about the relationship between certain environmental exposures and the cancers they regularly treat. However, a lack of comfort with these topics seems to have limited their discussions with families about the role of environmental exposures in childhood cancer pathogenesis. Although 77% of respondents suspected that some of the cases they saw had an environmental origin, their methods of taking environmental histories varied widely. Over 90% of respondents believed that more knowledge of the associations between environmental exposures and childhood cancer would be helpful in addressing these issues with patients. Conclusions: Although limited in size and representativeness of participating institutions, the results of this survey indicate a need for increased training for hematology/oncology clinicians about environmental health exposures related to cancer and prompt translation of emerging research findings in biomedical journals that clinicians read.

Purpose: Asparaginase (ASNase) is a standard and critical component in the therapy of childhood acute lymphoblastic leukemia (ALL), but it is also associated with several toxicities. Experimental design: We recently reported the results of an association study between ASNase pathway genes and event-free survival (EFS) in childhood patients with ALL. The same polymorphisms were interrogated here in relation to allergies, pancreatitis, and thrombotic events following treatment with E. coli ASNase. Results: Among patients of the discovery group, allergies, and pancreatitis were more frequent in individuals who are homozygous for the triple-repeat allele (3R) of the asparagine synthetase (ASNS) gene, resulting in remarkably higher risk of these toxicities associated with 3R3R genotype [OR for allergies, 14.6; 95% confidence interval (CI), 3.6–58.7; P < 0.0005 and OR for pancreatitis, 8.6; 95% CI, 2.0–37.3; P = 0.01]. In contrast, the ASNS haplotype *1 harboring double-repeat (2R) allele had protective effect against these adverse reactions (P ≤ 0.01). The same haplotype was previously reported to confer reduction in EFS. The risk effect of 3R3R genotype was not replicated in the validation cohort, whereas the protective effect of haplotype *1 against allergies was maintained (P ≤ 0.002). Analysis with additional polymorphisms in ASNS locus in lymphoblastoid cell lines showed that haplotype *1 is diversified in several subtypes of which one was associated with reduced in vitro sensitivity to ASNase (rs10486009, P = 0.01) possibly explaining an association seen in clinical setting. Conclusions: This finding might have implication for treatment individualization in ALL and other cancers using asparagine depletion strategies. Clin Cancer Res; 21(2); 329–34. ©2014 AACR. See related commentary by Avramis, p. 230

Treatment advances have increased survival in children with cancer, but subclinical, progressive, irreversible, and sometimes fatal treatment-related cardiovascular effects may appear years later. Cardio-oncologists have identified promising preventive and treatment strategies. Dexrazoxane provides long-term cardioprotection from doxorubicin-associated cardiotoxicity without compromising the efficacy of anticancer treatment. Continuous infusion of doxorubicin is as effective as bolus administration in leukemia treatment, but no evidence has indicated that it provides long-term cardioprotection; continuous infusions should be eliminated from pediatric cancer treatment. Angiotensin-converting enzyme inhibitors can delay the progression of subclinical and clinical cardiotoxicity. All survivors, regardless of whether they were treated with anthracyclines or radiation, should be monitored for systemic inflammation and the risk of premature cardiovascular disease. Echocardiographic screening must be supplemented with screening for biomarkers of cardiotoxicity and perhaps by identification of genetic susceptibilities to cardiovascular diseases; optimal strategies need to be identified. The health burden related to cancer treatment will increase as this population expands and ages.

Treatment for acute lymphoblastic leukemia (ALL) in adults confers a high risk of venous thromboembolic (VTE) complications. We describe the implementation and results of prophylactic anticoagulation guidelines in adults (18-50 years) treated on a Dana-Farber Cancer Institute ALL pediatric inspired consortium protocol from 2007 to 2013. A high rate of asparaginase related toxicity events, including thrombosis, resulted in a protocol amendment adding guidelines for prophylactic anticoagulation and a modified asparaginase dose and schedule. After excluding patients with Philadelphia positive ALL, a cohort of 36 patients were treated after the protocol amendment with prophylactic anticoagulation and compared to 49 patients who received no prophylactic anticoagulation. Bleeding complications were not significantly different in those treated with prophylactic anticoagulation compared with those enrolled prior to the amendment (p = 0.26). No patients on prophylactic anticoagulation had grade ≥ 3 bleeding. Prior to the amendment, the 2 year cumulative incidence of VTE post-induction was 41% compared to 28% while on prophylactic anticoagulation (p = 0.32). The 2 year cumulative incidence pulmonary embolus pre-amendment was 16% compared with 8% post-amendment (p = 0.34). Prophylactic anticoagulation can be safely administered to adults with ALL without increasing the number or severity of bleeding events and, in addition to modifications in the asparaginase regimen, resulted in a reduction in the cumulative incidence of VTE.

Introduction Minimal residual disease (MRD) in B lymphoblastic leukemia has been demonstrated to be a powerful predictor of clinical outcome in numerous studies in both children and adults. In this study, we evaluated 86 pediatric patients with both diagnostic and remission flow cytometry studies and compared expression of CD81, CD58, CD19, CD34, CD20, and CD38 in the detection of MRD. Methods We evaluated 86 patients with B lymphoblastic leukemia who had both diagnostic studies and remission studies for the presence of MRD using multicolor flow cytometry. We established our detection limit for identifying abnormal lymphoblasts using serial dilutions. We also compared flow cytometry findings with molecular MRD detection in a subset of patients. Results We found that we can resolve differences between hematogones and lymphoblasts in 85 of 86 cases using a combination of CD45, CD19, CD34, CD10, CD20, CD38, CD58, and CD81. Our detection limit using flow cytometry is 0.002% for detecting a population of abnormal B lymphoblasts. Comparison with MRD assessment by molecular methods showed a high concordance rate with flow cytometry findings. Conclusions Our study highlights importance of using multiple markers to detect MRD in B lymphoblastic leukemia. Our findings indicate that including both CD58 and CD81 markers in addition to CD19, CD34, CD20, CD38, and CD10 are helpful in MRD detection by flow cytometry.

Purpose This study compared the relative incidence of treatment-related toxicities and the event-free and overall survival between Hispanic and non-Hispanic children undergoing therapy for acute lymphoblastic leukemia (ALL) on Dana-Farber Cancer Institute ALL Consortium protocol 05-001. Patients and methods Secondary analysis of prospectively collected data from a phase III multicenter study in children and adolescents of 1–18 years with previously untreated ALL. Results Between 2005 and 2011, 794 eligible patients enrolled on DFCI 05-001, 730 of whom were included in this analysis (19% [N = 150] Hispanic, 73% [N = 580] non-Hispanic). Hispanic patients were more likely to be ≥10 years of age (32% vs. 24%, P = 0.045) at diagnosis. Toxicity analyses revealed that Hispanic patients had significantly lower cumulative incidence of bone fracture (P

In certain human cancers, the expression of critical oncogenes is driven from large regulatory elements, called super-enhancers, that recruit much of the cell’s transcriptional apparatus and are defined by extensive acetylation of histone H3 lysine 27 (H3K27ac). In a subset of T-cell acute lymphoblastic leukemia (T-ALL) cases, we found that heterozygous somatic mutations are acquired that introduce binding motifs for the MYB transcription factor in a precise noncoding site, which creates a super-enhancer upstream of the TAL1 oncogene. MYB binds to this new site and recruits its H3K27 acetylase–binding partner CBP, as well as core components of a major leukemogenic transcriptional complex that contains RUNX1, GATA-3, and TAL1 itself. Additionally, most endogenous super-enhancers found in T-ALL cells are occupied by MYB and CBP, which suggests a general role for MYB in super-enhancer initiation. Thus, this study identifies a genetic mechanism responsible for the generation of oncogenic super-enhancers in malignant cells.

With growing numbers of childhood cancer survivors, it becomes increasingly important to understand the long-term toxicities associated with cure from malignancy. Many survivors were exposed to cardiotoxic chemotherapeutic agents at young ages. Indeed, cardiotoxicity is a leading cause of treatment-related morbidity and mortality in survivors of childhood cancer, and anthracycline exposure is a leading cause of these late cardiac effects. Nonetheless, anthracyclines remain critical agents in treating many pediatric cancers. Strategies to prevent anthracycline-associated cardiotoxicity include limiting lifetime cumulative anthracycline doses and adding cardioprotectant agents, such as dexrazoxane, to anthracycline-based regimens. However, attempts to reduce the cardiotoxicity of anthracyclines must also consider their effect on anti-cancer efficacy as well as new potential toxicities. In survivors of childhood acute lymphoblastic leukemia, the data suggest that including dexrazoxane in anthracycline-based regimens can prevent heart damage, does not reduce anti-leukemic efficacy, and can be safely administered. The controversies associated with dexrazoxane exemplify the challenges of changing therapy in cancers with a relatively good chance of event-free survival in efforts to prevent long-term sequelae. Studies of very-long-term survivor cohorts will continue to inform current practices. Continued efforts are needed to minimize cardiotoxic exposures during cancer treatment, to deliver safe and effective cardioprotectant measures when cardiotoxic agents cannot be avoided, to identify patients at greatest risk of serious cardiac toxicity, and to educate providers in the optimal care of survivors.

Acute lymphoblastic leukemia (ALL) is a hematopoietic malignancy derived from immature B-lymphoid and T-lymphoid cells (T-ALL). In T-ALL, there is an early T-cell progenitor (ETP) subgroup that has a very high risk for relapse. In this study, we used mitochondrial BH3 profiling to determine antiapoptotic protein dependencies in T-ALL. We found that T-ALL cell lines and primary patient samples are dependent upon BCL-XL, except when the cancer bears an ETP phenotype, in which case it is BCL-2 dependent. These distinctions directly relate to differential sensitivity to the BH3 mimetics ABT-263 and ABT-199, both in vitro and in vivo. We thus describe for the first time a change of antiapoptotic protein dependence that is related to the differentiation stage of the leukemic clone. Our findings demonstrate that BCL-2 is a clinically relevant target for therapeutic intervention with ABT-199 in ETP-ALL. Significance: ETP T-ALL is a treatment-resistant subtype of T-ALL for which novel targeted therapies are urgently needed. We have discovered, through BH3 profiling, that ETP-ALL is BCL-2 dependent and is very sensitive to in vitro and in vivo treatment with ABT-199, a drug well tolerated in clinical trials. Cancer Discov; 4(9); 1074–87. ©2014 AACR. This article is highlighted in the In This Issue feature, p. 973

Advances in treating childhood cancers over the past 40 years have more than doubled 5-year survival rates. More effective use of chemotherapeutic agents has been key to this success. However, the increase has come at a price: chronic conditions are significantly more prevalent in long-term survivors of childhood cancer than they are in the general population, and managing these survivors can be challenging. In patients receiving anthracyclines, cardiotoxicity is the leading cause of morbidity and mortality after relapse and second malignancies. More than 50% of patients exposed to anthracyclines exhibit some form of cardiac dysfunction within 20 years after completing chemotherapy, and about 5% develop heart failure. These conditions greatly reduce the quality of life of the individual and also consume substantial amounts of healthcare resources. Dexrazoxane has been used to reduce anthracycline-related cardiotoxicity in children with cancer, but in 2011, the European Medicines Agency determined, on what it acknowledged were limited data, that dexrazoxane was contraindicated in children. Here, we review the evidence for the clinical effects of dexrazoxane in children. Studies published since 2011 have confirmed the efficacy of dexrazoxane in preventing or reducing anthracycline-related cardiotoxicity in children with cancer, and no new evidence of increased risks for recurrence of primary or second malignancies, or reductions in antitumor efficacy has been reported. As a result, we believe that dexrazoxane should be available to children with high-risk cancers to reduce the risk of cardiotoxicity associated with high-dose anthracycline treatment.