Distinct pattern of genomic breakpoints in CML and BCR::ABL1-positive ALL: analysis of 971 patients.

BACKGROUND: The BCR::ABL1 is a hallmark of chronic myeloid leukemia (CML) and is also found in acute lymphoblastic leukemia (ALL). Most genomic breaks on the BCR side occur in two regions - Major and minor - leading to p210 and p190 fusion proteins, respectively. METHODS: By multiplex long-distance PCR or next-generation sequencing technology we characterized the BCR::ABL1 genomic fusion in 971 patients (adults and children, with CML and ALL: pediatric ALL: n = 353; pediatric CML: n = 197; adult ALL: n = 166; adult CML: n = 255 patients) and designed "Break-App" web tool to allow visualization and various analyses of the breakpoints. Pearson's Chi-Squared test, Kolmogorov-Smirnov test and logistic regression were used for statistical analyses. RESULTS: Detailed analysis showed a non-random distribution of breaks in both BCR regions, whereas ABL1 breaks were distributed more evenly. However, we found a significant difference in the distribution of breaks between CML and ALL. We found no association of breakpoints with any type of interspersed repeats or DNA motifs. With a few exceptions, the primary structure of the fusions suggests non-homologous end joining being responsible for the BCR and ABL1 gene fusions. Analysis of reciprocal ABL1::BCR fusions in 453 patients showed mostly balanced translocations without major deletions or duplications. CONCLUSIONS: Taken together, our data suggest that physical colocalization and chromatin accessibility, which change with the developmental stage of the cell (hence the difference between ALL and CML), are more critical factors influencing breakpoint localization than presence of specific DNA motifs.

Whole-genome sequencing facilitates patient-specific quantitative PCR-based minimal residual disease monitoring in acute lymphoblastic leukaemia, neuroblastoma and Ewing sarcoma.

BACKGROUND: Minimal residual disease (MRD) measurement is a cornerstone of contemporary acute lymphoblastic leukaemia (ALL) treatment. The presence of immunoglobulin (Ig) and T cell receptor (TCR) gene recombinations in leukaemic clones allows widespread use of patient-specific, DNA-based MRD assays. In contrast, paediatric solid tumour MRD remains experimental and has focussed on generic assays targeting tumour-specific messenger RNA, methylated DNA or microRNA. METHODS: We examined the feasibility of using whole-genome sequencing (WGS) data to design tumour-specific polymerase chain reaction (PCR)-based MRD tests (WGS-MRD) in 18 children with high-risk relapsed cancer, including ALL, high-risk neuroblastoma (HR-NB) and Ewing sarcoma (EWS) (n = 6 each). RESULTS: Sensitive WGS-MRD assays were generated for each patient and allowed quantitation of 1 tumour cell per 10-4 (0.01%)-10-5 (0.001%) mononuclear cells. In ALL, WGS-MRD and Ig/TCR-MRD were highly concordant. WGS-MRD assays also showed good concordance between quantitative PCR and droplet digital PCR formats. In serial clinical samples, WGS-MRD correlated with disease course. In solid tumours, WGS-MRD assays were more sensitive than RNA-MRD assays. CONCLUSIONS: WGS facilitated the development of patient-specific MRD tests in ALL, HR-NB and EWS with potential clinical utility in monitoring treatment response. WGS data could be used to design patient-specific MRD assays in a broad range of tumours.

Measurable residual disease analysis in paediatric acute lymphoblastic leukaemia patients with ABL-class fusions.

BACKGROUND: ABL-class fusions including NUP214-ABL1 and EBF1-PDGFRB occur in high risk acute lymphoblastic leukaemia (ALL) with gene expression patterns similar to BCR-ABL-positive ALL. Our aim was to evaluate new DNA-based measurable residual disease (MRD) tests detecting these fusions and IKZF1-deletions in comparison with conventional immunoglobulin/T-cell receptor (Ig/TCR) markers. METHODS: Precise genomic breakpoints were defined from targeted or whole genome next generation sequencing for ABL-fusions and BCR-ABL1. Quantitative PCR assays were designed and used to re-measure MRD in remission bone marrow samples previously tested using Ig/TCR markers. All MRD testing complied with EuroMRD guidelines. RESULTS: ABL-class patients had 46% 5year event-free survival and 79% 5year overall survival. All had sensitive fusion tests giving high concordance between Ig/TCR and ABL-class fusion results (21 patients, n = 257 samples, r2 = 0.9786, P < 0.0001) and Ig/TCR and IKZF1-deletion results (9 patients, n = 143 samples, r2 = 0.9661, P < 0.0001). In contrast, in BCR-ABL1 patients, Ig/TCR and BCR-ABL1 tests were discordant in 32% (40 patients, n = 346 samples, r2 = 0.4703, P < 0.0001) and IKZF1-deletion results were closer to Ig/TCR (25 patients, n = 176, r2 = 0.8631, P < 0.0001). CONCLUSIONS: MRD monitoring based on patient-specific assays detecting gene fusions or recurrent assays for IKZF1-deletions is feasible and provides good alternatives to Ig/TCR tests to monitor MRD in ABL-class ALL.

Methotrexate-related central neurotoxicity: clinical characteristics, risk factors and genome-wide association study in children treated for acute lymphoblastic leukemia.

Symptomatic methotrexate-related central neurotoxicity (MTX neurotoxicity) is a severe toxicity experienced during acute lymphoblastic leukemia (ALL) therapy with potential long-term neurologic complications. Risk factors and long-term outcomes require further study. We conducted a systematic, retrospective review of 1,251 consecutive Australian children enrolled on Berlin-Frankfurt-Münster or Children's Oncology Group-based protocols between 1998-2013. Clinical risk predictors for MTX neurotoxicity were analyzed using regression. A genome-wide association study (GWAS) was performed on 48 cases and 537 controls. The incidence of MTX neurotoxicity was 7.6% (n=95 of 1,251), at a median of 4 months from ALL diagnosis and 8 days after intravenous or intrathecal MTX. Grade 3 elevation of serum aspartate aminotransferase (P=0.005, odds ratio 2.31 [range, 1.28-4.16]) in induction/consolidation was associated with MTX neurotoxicity, after accounting for the only established risk factor, age ≥10 years. Cumulative incidence of CNS relapse was increased in children where intrathecal MTX was omitted following symptomatic MTX neurotoxicity (n=48) compared to where intrathecal MTX was continued throughout therapy (n=1,174) (P=0.047). Five-year central nervous system relapse-free survival was 89.2 4.6% when intrathecal MTX was ceased compared to 95.4 0.6% when intrathecal MTX was continued. Recurrence of MTX neurotoxicity was low (12.9%) for patients whose intrathecal MTX was continued after their first episode. The GWAS identified single-nucletide polymorphism associated with MTX neurotoxicity near genes regulating neuronal growth, neuronal differentiation and cytoskeletal organization (P<1x10-6). In conclusion, increased serum aspartate aminotransferase and age ≥10 years at diagnosis were independent risk factors for MTX neurotoxicity. Our data do not support cessation of intrathecal MTX after a first MTX neurotoxicity event.

Prospective longitudinal evaluation of treatment-related toxicity and health-related quality of life during the first year of treatment for pediatric acute lymphoblastic leukemia.

BACKGROUND: Pediatric acute lymphoblastic leukemia (ALL) therapy is accompanied by treatment-related toxicities (TRTs) and impaired quality of life. In Australia and New Zealand, children with ALL are treated with either Children's Oncology Group (COG) or international Berlin-Frankfurt-Munster (iBFM) Study Group-based therapy. We conducted a prospective registry study to document symptomatic TRTs (venous thrombosis, neurotoxicity, pancreatitis and bone toxicity), compare TRT outcomes to retrospective TRT data, and measure the impact of TRTs on children's general and cancer-related health-related quality of life (HRQoL) and parents' emotional well-being. METHODS: Parents of children with newly diagnosed ALL were invited to participate in the ASSET (Acute Lymphoblastic Leukaemia Subtypes and Side Effects from Treatment) study and a prospective, longitudinal HRQoL study. TRTs were reported prospectively and families completed questionnaires for general (Healthy Utility Index Mark 3) and cancer specific (Pediatric Quality of Life Inventory (PedsQL)-Cancer Module) health related quality of life as well the Emotion Thermometer to assess emotional well-being. RESULTS: Beginning in 2016, 260 pediatric patients with ALL were enrolled on the TRT registry with a median age at diagnosis of 59 months (range 1-213 months), 144 males (55.4%), majority with Pre-B cell immunophenotype, n = 226 (86.9%), 173 patients (66.5%) treated according to COG platform with relatively equal distribution across risk classification sub-groups. From 2018, 79 families participated in the HRQoL study through the first year of treatment. There were 74 TRT recorded, reflecting a 28.5% risk of developing a TRT. Individual TRT incidence was consistent with previous studies, being 7.7% for symptomatic VTE, 11.9% neurotoxicity, 5.4% bone toxicity and 5.0% pancreatitis. Children's HRQoL was significantly lower than population norms throughout the first year of treatment. An improvement in general HRQoL, measured by the HUI3, contrasted with the lack of improvement in cancer-related HRQoL measured by the PedsQL Cancer Module over the first 12 months. There were no persisting differences in the HRQoL impact of COG compared to iBFM therapy. CONCLUSIONS: It is feasible to prospectively monitor TRT incidence and longitudinal HRQoL impacts during ALL therapy. Early phases of ALL therapy, regardless of treatment platform, result in prolonged reductions in cancer-related HRQoL.

Mouse models of high-risk neuroblastoma.

Informative and realistic mouse models of high-risk neuroblastoma are central to understanding mechanisms of tumour initiation, progression, and metastasis. They also play vital roles in validating tumour drivers and drug targets, as platforms for assessment of new therapies and in the generation of drug sensitivity data that can inform treatment decisions for individual patients. This review will describe genetically engineered mouse models of specific subsets of high-risk neuroblastoma, the development of patient-derived xenograft models that more broadly represent the diversity and heterogeneity of the disease, and models of primary and metastatic disease. We discuss the research applications, advantages, and limitations of each model type, the importance of model repositories and data standards for supporting reproducible, high-quality research, and potential future directions for neuroblastoma mouse models.

Determinants of social functioning among adolescents and young adults with cancer: A systematic review.

OBJECTIVES: Survivors of adolescent and young adult (AYA) cancer report deficits in social functioning relative to healthy peers. Identifying factors related to their social functioning is critical to improve their long-term social outcomes. This review addressed: (1) How is social functioning defined and measured among studies of AYAs who have had cancer? (2) What factors have quantitatively/qualitatively are associated with/predictors of social functioning? and (3) What associated factors/predictors of social functioning are modifiable and amenable to intervention? METHODS: A systematic review was conducted to identify publications from 2000 to 2021, meeting these criteria: (1) mean/median age at diagnosis/treatment 13-40, (2) assessed social functioning with a validated measure and included factors associated with/predictive of social functioning and/or qualitatively assessed young people's perceptions of factors related to their social functioning and (3) was peer-reviewed/published in English. RESULTS: Thirty-seven publications were included. Definitions and measures of social functioning varied, and factors related to social functioning varied based on definition. Factors most commonly associated with decreased social functioning included treatment status (receiving or completed treatment), poor physical functioning, depression, negative body image, engaging in social comparisons, social/cultural stigma around cancer, and fatigue. Increased social functioning was most commonly associated with social support and the quality/age-appropriateness of care. CONCLUSIONS: Social functioning is multidimensional construct for AYAs diagnosed with cancer and may not be adequately assessed with measures of adjustment or quality of life. Future studies should clarify how to optimally define and measure social functioning in this population, to ensure their functioning can be protected and promoted long-term.

Outcomes for Australian children with relapsed/refractory acute lymphoblastic leukaemia treated with blinatumomab.

We report on the Australian experience of blinatumomab for treatment of 24 children with relapsed/refractory precursor B-cell acute lymphoblastic leukaemia (B-ALL) and high-risk genetics, resulting in a minimal residual disease (MRD) response rate of 58%, 2-year progression-free survival (PFS) of 39% and 2-year overall survival of 63%. In total, 83% (n = 20/24) proceeded to haematopoietic stem cell transplant, directly after blinatumomab (n = 12) or following additional salvage therapy (n = 8). Four patients successfully received CD19-directed chimeric antigen receptor T-cell therapy despite prior blinatumomab exposure. Inferior 2-year PFS was associated with MRD positivity (20%, n = 15) and in KMT2A-rearranged infants (15%, n = 9). Our findings highlight that not all children with relapsed/refractory B-ALL respond to blinatumomab and factors such as blast genotype may affect prognosis.

The Australia and New Zealand Cardio-Oncology Registry: evaluation of chemotherapy-related cardiotoxicity in a national cohort of paediatric cancer patients.

Cancer therapy related cardiac dysfunction (CTRCD) is an area of increasing focus, particularly during the survivorship period, for paediatric, adolescent and adult cancer survivors. With the advent of immunotherapy and targeted therapy, there is a new set of mechanisms from which paediatric and young adult patients with cancer may suffer cardiovascular injury. Furthermore, cardiovascular disease is the leading cause of morbidity and mortality in the survivorship period. The recently established Australian Cardio-Oncology Registry is the largest and only population-based cardiotoxicity database of paediatric and adolescent and young adult oncology patients in the world, and the first paediatric registry that will document cardiotoxicity caused by chemotherapy and novel targeted therapies using a prospective approach. The database is designed for comprehensive data collection and evaluation of the Australian practice in terms of diagnosis and management of CTRCD. Using the Australian Cardio-Oncology Registry critical clinical information will be collected regarding predisposing factors for the development of CTRCD, the rate of subclinical left ventricular dysfunction and transition to overt heart failure, further research into protectant molecules against cardiac dysfunction and aid in the discovery of which genetic variants predispose to CTRCD. A health economic arm of the study will assess the cost/benefit of both the registry and cardio-oncology clinical implementation. Finally, an imaging arm will establish if exercise cardiac magnetic resonance imaging and VO2 max testing is a more sensitive predictor of cardiac reserve in paediatric and adolescent and young adult oncology patients exposed to cardiac toxic therapies.

CD30 and ALK combination therapy has high therapeutic potency in RANBP2-ALK-rearranged epithelioid inflammatory myofibroblastic sarcoma.

BACKGROUND: Epithelioid inflammatory myofibroblastic sarcoma (eIMS) is characterised by perinuclear ALK localisation, CD30 expression and early relapse despite crizotinib treatment. We aimed to identify therapies to prevent and/or treat ALK inhibitor resistance. METHODS: Malignant ascites, from an eIMS patient at diagnosis and following multiple relapses, were used to generate matched diagnosis and relapse xenografts. RESULTS: Xenografts were validated by confirmation of RANBP2-ALK rearrangement, perinuclear ALK localisation and CD30 expression. Although brentuximab-vedotin (BV) demonstrated single-agent activity, tumours regrew during BV therapy. BV resistance was associated with reduced CD30 expression and induction of ABCB1. BV resistance was reversed in vitro by tariquidar, but combination BV and tariquidar treatment only briefly slowed xenograft growth compared with BV alone. Combining BV with either crizotinib or ceritinib resulted in marked tumour shrinkage in both xenograft models, and resulted in prolonged tumour-free survival in the diagnosis compared with the relapse xenograft. CONCLUSIONS: CD30 is a therapeutic target in eIMS. BV efficacy is limited by the rapid emergence of resistance. Prolonged survival with combination ALK and CD30-targeted-therapy in the diagnosis model provides the rationale to trial this combination in eIMS patients at diagnosis. This combination could also be considered for other CD30-positive, ALK-rearranged malignancies.

Accelerating development of high-risk neuroblastoma patient-derived xenograft models for preclinical testing and personalised therapy.

BACKGROUND: Predictive preclinical models play an important role in the assessment of new treatment strategies and as avatar models for personalised medicine; however, reliable and timely model generation is challenging. We investigated the feasibility of establishing patient-derived xenograft (PDX) models of high-risk neuroblastoma from a range of tumour-bearing patient materials and assessed approaches to improve engraftment efficiency. METHODS: PDX model development was attempted in NSG mice by using tumour materials from 12 patients, including primary and metastatic solid tumour samples, bone marrow, pleural fluid and residual cells from cytogenetic analysis. Subcutaneous, intramuscular and orthotopic engraftment were directly compared for three patients. RESULTS: PDX models were established for 44% (4/9) of patients at diagnosis and 100% (5/5) at relapse. In one case, attempted engraftment from pleural fluid resulted in an EBV-associated atypical lymphoid proliferation. Xenogeneic graft versus host disease was observed with attempted engraftment from lymph node and bone marrow tumour samples but could be prevented by T-cell depletion. Orthotopic engraftment was more efficient than subcutaneous or intramuscular engraftment. CONCLUSIONS: High-risk neuroblastoma PDX models can be reliably established from diverse sample types. Orthotopic implantation allows more rapid model development, increasing the likelihood of developing an avatar model within a clinically useful timeframe.

Optimization of a clofarabine-based drug combination regimen for the preclinical evaluation of pediatric acute lymphoblastic leukemia.

BACKGROUND: The aim of this study was to improve the predictive power of patient-derived xenografts (PDXs, also known as mouse avatars) to more accurately reflect outcomes of clofarabine-based treatment in pediatric acute lymphoblastic leukemia (ALL) patients. PROCEDURE: Pharmacokinetic (PK) studies were conducted using clofarabine at 3.5 to 15 mg/kg in mice. PDXs were established from relapsed/refractory ALL patients who exhibited good or poor responses to clofarabine. PDX engraftment and response to clofarabine (either as a single agent or in combinations) were assessed based on stringent objective response measures modeled after the clinical setting. RESULTS: In naïve immune-deficient NSG mice, we determined that a clofarabine dose of 3.5 mg/kg resulted in systemic exposures equivalent to those achieved in pediatric ALL patients treated with clofarabine-based regimens. This dose was markedly lower than the doses of clofarabine used in previously reported preclinical studies (typically 30-60 mg/kg) and, when scheduled consistent with the clinical regimen (daily × 5), resulted in 34-fold lower clofarabine exposures. Using a well-tolerated clofarabine/etoposide/cyclophosphamide combination regimen, we then found that the responses of PDXs better reflected the clinical responses of the patients from whom the PDXs were derived. CONCLUSIONS: This study has identified an in vivo clofarabine treatment regimen that reflects the clinical responses of relapsed/refractory pediatric ALL patients. This regimen could be used prospectively to identify patients who might benefit from clofarabine-based treatment. Our findings are an important step toward individualizing prospective patient selection for the use of clofarabine in relapsed/refractory pediatric ALL patients and highlight the need for detailed PK evaluation in murine PDX models.

Enrolment in paediatric oncology early-phase clinical trials: The health-care professionals' perspective.

AIM: Approximately 20-30% of children/adolescents with cancer will not respond to standard therapies. These children are usually offered experimental treatment in the form of an early-phase clinical trial. We examined the perspectives of health-care professionals (HCPs) regarding obtaining informed consent for early-phase trials in paediatric oncology. METHODS: We collected survey data from 87 HCPs working in paediatric cancer centres across Australia and New Zealand. RESULTS: HCPs were, on average, 44 years old (range = 25-74), with 15.8 years' experience in paediatric oncology (range = 1-40). Few HCPs (17.4%) received training for early-phase trial consent; however, most were willing to attend training (77.9%). HCPs (61.6%) reported that they informed families about early-phase trials without any attempt to influence their decision. However, 23.3% of HCPs reported that they informed families that their child would benefit. HCPs' main obstacle in obtaining consent was their perception of parents' eagerness to 'try anything' (52.3%). HCPs perceived that many parents misunderstood key clinical trials concepts, with 25.2% of HCPs believing that not being given clear information influenced parents' decisions. Physicians were more likely than social workers/nurses to inform families that other children will benefit from enrolment in the study. Social workers/nurses appeared to rate the chance of benefits for the patient higher than physicians. CONCLUSIONS: HCPs may experience difficulty conducting early-phase trial consultations and obtaining valid informed consent. Our study highlights the need for formal training for HCPs and additional patient education tools.

Interleukin 2 with anti-GD2 antibody ch14.18/CHO (dinutuximab beta) in patients with high-risk neuroblastoma (HR-NBL1/SIOPEN): a multicentre, randomised, phase 3 trial.

BACKGROUND: Immunotherapy with the chimeric anti-GD2 monoclonal antibody dinutuximab, combined with alternating granulocyte-macrophage colony-stimulating factor and intravenous interleukin-2 (IL-2), improves survival in patients with high-risk neuroblastoma. We aimed to assess event-free survival after treatment with ch14.18/CHO (dinutuximab beta) and subcutaneous IL-2, compared with dinutuximab beta alone in children and young people with high-risk neuroblastoma. METHODS: We did an international, open-label, phase 3, randomised, controlled trial in patients with high-risk neuroblastoma at 104 institutions in 12 countries. Eligible patients were aged 1-20 years and had MYCN-amplified neuroblastoma with stages 2, 3, or 4S, or stage 4 neuroblastoma of any MYCN status, according to the International Neuroblastoma Staging System. Patients were eligible if they had been enrolled at diagnosis in the HR-NBL1/SIOPEN trial, had completed the multidrug induction regimen (cisplatin, carboplatin, cyclophosphamide, vincristine, and etoposide, with or without topotecan, vincristine, and doxorubicin), had achieved a disease response that fulfilled prespecified criteria, had received high-dose therapy (busulfan and melphalan or carboplatin, etoposide, and melphalan) and had received radiotherapy to the primary tumour site. In this component of the trial, patients were randomly assigned (1:1) to receive dinutuximab beta (20 mg/m2 per day as an 8 h infusion for 5 consecutive days) or dinutuximab beta plus subcutaneous IL-2 (6 × 106 IU/m2 per day on days 1-5 and days 8-12 of each cycle) with the minimisation method to balance randomisation for national groups and type of high-dose therapy. All participants received oral isotretinoin (160 mg/m2 per day for 2 weeks) before the first immunotherapy cycle and after each immunotherapy cycle, for six cycles. The primary endpoint was 3-year event-free survival, analysed by intention to treat. This trial was registered with ClinicalTrials.gov, number NCT01704716, and EudraCT, number 2006-001489-17, and recruitment to this randomisation is closed. FINDINGS: Between Oct 22, 2009, and Aug 12, 2013, 422 patients were eligible to participate in the immunotherapy randomisation, of whom 406 (96%) were randomly assigned to a treatment group (n=200 to dinutuximab beta and n=206 to dinutuximab beta with subcutaneous IL-2). Median follow-up was 4·7 years (IQR 3·9-5·3). Because of toxicity, 117 (62%) of 188 patients assigned to dinutuximab beta and subcutaneous IL-2 received their allocated treatment, by contrast with 160 (87%) of 183 patients who received dinutuximab beta alone (p<0·0001). 3-year event-free survival was 56% (95% CI 49-63) with dinutuximab beta (83 patients had an event) and 60% (53-66) with dinutuximab beta and subcutaneous IL-2 (80 patients had an event; p=0·76). Four patients died of toxicity (n=2 in each group); one patient in each group while receiving immunotherapy (n=1 congestive heart failure and pulmonary hypertension due to capillary leak syndrome; n=1 infection-related acute respiratory distress syndrome), and one patient in each group after five cycles of immunotherapy (n=1 fungal infection and multi-organ failure; n=1 pulmonary fibrosis). The most common grade 3-4 adverse events were hypersensitivity reactions (19 [10%] of 185 patients in the dinutuximab beta group vs 39 [20%] of 191 patients in the dinutuximab plus subcutaneous IL-2 group), capillary leak (five [4%] of 119 vs 19 [15%] of 125), fever (25 [14%] of 185 vs 76 [40%] of 190), infection (47 [25%] of 185 vs 64 [33%] of 191), immunotherapy-related pain (19 [16%] of 122 vs 32 [26%] of 124), and impaired general condition (30 [16%] of 185 vs 78 [41%] of 192). INTERPRETATION: There is no evidence that addition of subcutaneous IL-2 to immunotherapy with dinutuximab beta, given as an 8 h infusion, improved outcomes in patients with high-risk neuroblastoma who had responded to standard induction and consolidation treatment. Subcutaneous IL-2 with dinutuximab beta was associated with greater toxicity than dinutuximab beta alone. Dinutuximab beta and isotretinoin without subcutaneous IL-2 should thus be considered the standard of care until results of ongoing randomised trials using a modified schedule of dinutuximab beta and subcutaneous IL-2 are available. FUNDING: European Commission 5th Frame Work Grant, St. Anna Kinderkrebsforschung, Fondation ARC pour la recherche sur le Cancer.

A risk score including microdeletions improves relapse prediction for standard and medium risk precursor B-cell acute lymphoblastic leukaemia in children.

To prevent relapse, high risk paediatric acute lymphoblastic leukaemia (ALL) is treated very intensively. However, most patients who eventually relapse have standard or medium risk ALL with low minimal residual disease (MRD) levels. We analysed recurrent microdeletions and other clinical prognostic factors in a cohort of 475 uniformly treated non-high risk precursor B-cell ALL patients with the aim of better predicting relapse and refining risk stratification. Lower relapse-free survival at 7 years (RFS) was associated with IKZF1 intragenic deletions (P < 0·0001); P2RY8-CRLF2 gene fusion (P < 0·0004); Day 33 MRD>5 × 10-5 (P < 0·0001) and High National Cancer Institute (NCI) risk (P < 0·0001). We created a predictive model based on a risk score (RS) for deletions, MRD and NCI risk, extending from an RS of 0 (RS0) for patients with no unfavourable factors to RS2 +  for patients with 2 or 3 high risk factors. RS0, RS1, and RS2 +  groups had RFS of 93%, 78% and 49%, respectively, and overall survival (OS) of 99%, 91% and 71%. The RS provided greater discrimination than MRD-based risk stratification into standard (89% RFS, 96% OS) and medium risk groups (79% RFS, 91% OS). We conclude that this RS may enable better early therapeutic stratification and thus improve cure rates for childhood ALL.

Increased Survival for Children With Acute Myeloid Leukemia Results From Improved Postrelapse Treatment.

BACKGROUND: The treatment for pediatric acute myeloid leukemia (AML) has not changed significantly over the past 3 decades, yet outcomes have improved with cure rates increasing from 30% to over 60% of all newly diagnosed children over this period. This improvement in survival has been attributed to both treatment intensification and improved supportive care over the decades, although the precise impact of each remains unknown. PATIENTS AND METHODS: We retrospectively analyzed a unique cohort of 276 patients with de novo AML diagnosed in childhood, all treated with the same chemotherapy protocol over a 25-year period from 1986 to 2012. RESULTS: The contemporary cohort (2000-2012), compared with the historical cohort (1986-1999) had significantly improved overall survival (75% vs. 50%; hazard ratio, 2.17; 95% confidence interval, 1.15-2.93), lower disease-related mortality (38% vs. 19%, P=0.02) and were significantly more likely to receive an allogeneic transplant after relapse (stem cell transplantation [SCT], 73% vs. 12%; P<0.0001). Allogeneic transplant postrelapse was associated with a significantly improved survival across the entire cohort (overall survival 50% for allogeneic SCT vs. 12% for autologous or none, P<0.0001). There was no significant difference between the contemporary and historical cohorts in treatment-related mortality (13% vs. 7%, P=0.42) or relapse rates after induction (50% in older cohort vs. 40% in recent era, P=0.25), suggesting consistency of induction treatment efficacy and toxicity across the 2 periods. CONCLUSIONS: This data suggests improved survival in pediatric AML in the modern era has predominantly resulted from changes in treatment after relapse, including increased use of allogeneic SCT.

Alectinib is effective, safe and tolerable in an adolescent with stage IVB ALK-rearranged adenocarcinoma of the lung.

Anaplastic lymphoma kinase (ALK) inhibitors such as crizotinib and alectinib have been shown to have significant activity in ALK-rearranged non-small cell lung cancers (NSCLC). There are no data for alectinib's safety or efficacy in younger patients, though it is superior to crizotinib in adult trials. We present a 14-year old girl diagnosed with stage IV-B ALK-positive adenocarcinoma of the lung after presenting with cough and fever. She was commenced on alectinib at adult dose and has had sustained complete metabolic remission for 9 months. She is the youngest patient with lung adenocarcinoma to be treated with alectinib.

Busulfan and melphalan versus carboplatin, etoposide, and melphalan as high-dose chemotherapy for high-risk neuroblastoma (HR-NBL1/SIOPEN): an international, randomised, multi-arm, open-label, phase 3 trial.

BACKGROUND: High-dose chemotherapy with haemopoietic stem-cell rescue improves event-free survival in patients with high-risk neuroblastoma; however, which regimen has the greatest patient benefit has not been established. We aimed to assess event-free survival after high-dose chemotherapy with busulfan and melphalan compared with carboplatin, etoposide, and melphalan. METHODS: We did an international, randomised, multi-arm, open-label, phase 3 cooperative group clinical trial of patients with high-risk neuroblastoma at 128 institutions in 18 countries that included an open-label randomised arm in which high-dose chemotherapy regimens were compared. Patients (age 1-20 years) with neuroblastoma were eligible to be randomly assigned if they had completed a multidrug induction regimen (cisplatin, carboplatin, cyclophosphamide, vincristine, and etoposide with or without topotecan, vincristine, and doxorubicin) and achieved an adequate disease response. Patients were randomly assigned (1:1) to busulfan and melphalan or to carboplatin, etoposide, and melphalan by minimisation, balancing age at diagnosis, stage, MYCN amplification, and national cooperative clinical group between groups. The busulfan and melphalan regimen comprised oral busulfan (150 mg/m2 given on 4 days consecutively in four equal doses); after Nov 8, 2007, intravenous busulfan was given (0·8-1·2 mg/kg per dose for 16 doses according to patient weight). After 24 h, an intravenous melphalan dose (140 mg/m2) was given. Doses of busulfan and melphalan were modified according to bodyweight. The carboplatin, etoposide, and melphalan regimen consisted of carboplatin continuous infusion of area under the plasma concentration-time curve 4·1 mg/mL per min per day for 4 days, etoposide continuous infusion of 338 mg/m2 per day for 4 days, and melphalan 70 mg/m2 per day for 3 days, with doses for all three drugs modified according to bodyweight and glomerular filtration rate. Stem-cell rescue was given after the last dose of high-dose chemotherapy, at least 24 h after melphalan in patients who received busulfan and melphalan and at least 72 h after carboplatin etoposide, and melphalan. All patients received subsequent local radiotherapy to the primary tumour site followed by maintenance therapy. The primary endpoint was 3-year event-free survival, analysed by intention to treat. This trial is registered with ClinicalTrials.gov, number NCT01704716, and EudraCT, number 2006-001489-17. FINDINGS: Between June 24, 2002, and Oct 8, 2010, 1347 patients were enrolled and 676 were eligible for random allocation, 598 (88%) of whom were randomly assigned: 296 to busulfan and melphalan and 302 to carboplatin, etoposide, and melphalan. Median follow-up was 7·2 years (IQR 5·3-9·2). At 3 years, 146 of 296 patients in the busulfan and melphalan group and 188 of 302 in the carboplatin, etoposide, and melphalan group had an event; 3-year event-free survival was 50% (95% CI 45-56) versus 38% (32-43; p=0·0005). Nine patients in the busulfan and melphalan group and 11 in the carboplatin, etoposide, and melphalan group had died without relapse by 5 years. Severe life-threatening toxicities occurred in 13 (4%) patients who received busulfan and melphalan and 29 (10%) who received carboplatin, etoposide, and melphalan. The most frequent grade 3-4 adverse events were general condition (74 [26%] of 281 in the busulfan and melphalan group vs 103 [38%] of 270 in the carboplatin, etoposide, and melphalan group), infection (55 [19%] of 283 vs 74 [27%] of 271), and stomatitis (138 [49%] of 284 vs 162 [59%] of 273); 60 (22%) of 267 patients in the busulfan and melphalan group had Bearman grades 1-3 veno-occlusive disease versus 21 (9%) of 239 in the carboplatin, etoposide, and melphalan group. INTERPRETATION: Busulfan and melphalan improved event-free survival in children with high-risk neuroblastoma with an adequate response to induction treatment and caused fewer severe adverse events than did carboplatin, etoposide, and melphalan. Busulfan and melphalan should thus be considered standard high-dose chemotherapy and ongoing randomised studies will continue to aim to optimise treatment for high-risk neuroblastoma. FUNDING: European Commission 5th Framework Grant and the St Anna Kinderkrebsforschung.

Haematopoietic stem cell transplantation for primary immunodeficiency syndromes: A 5-year single-centre experience.

AIM: Haematopoietic stem cell transplantation (HSCT) is a central therapy in the treatment of primary immunodeficiency diseases (PIDs). Over the past 5 years, outcomes have been greatly improved due to earlier diagnosis, improved donor availability, advancements in graft manipulation and the use of less toxic preparative regimens. We present a 5-year audit of HSCT for PID at a single Australian tertiary hospital. METHODS: Retrospective case note review identified diagnosis, pre-transplant medical morbidity, transplant protocol, engraftment, adverse events, post-transplant immune reconstitution and general health. RESULTS: A total of 22 patients with PID underwent 24 HSCTs at our institution between 2012 and 2016. The most common indications were severe combined immunodeficiency, chronic granulomatous disease and familial haemophagocytic lymphohistiocytosis, with a genetic diagnosis in all but two patients. Reduced intensity or reduced toxicity conditioning was used in 91% of cases, and 75% of the donors were unrelated. Transplant-related mortality at day +100 was 9.5%, and cumulative overall survival was 86%. There were three mortalities, all secondary to viral infection, one of which occurred in the context of graft failure. Two patients remained on immune support, with the remainder achieving adequate immune reconstitution. CONCLUSIONS: The outcomes for HSCT for PIDs performed at Sydney Children's Hospital were in line with the world's best practice. HSCT should be considered a potential therapeutic option for all Australian PID patients with a valid disease indication.

Persistent MRD before and after allogeneic BMT predicts relapse in children with acute lymphoblastic leukaemia.

Minimal residual disease (MRD) during early chemotherapy is a powerful predictor of relapse in acute lymphoblastic leukaemia (ALL) and is used in children to determine eligibility for allogeneic haematopoietic stem cell transplantation (HSCT) in first (CR1) or later complete remission (CR2/CR3). Variables affecting HSCT outcome were analysed in 81 children from the ANZCHOG ALL8 trial. The major cause of treatment failure was relapse, with a cumulative incidence of relapse at 5 years (CIR) of 32% and treatment-related mortality of 8%. Leukaemia-free survival (LFS) and overall survival (OS) were similar for HSCT in CR1 (LFS 62%, OS 83%, n = 41) or CR2/CR3 (LFS 60%, OS 72%, n = 40). Patients achieving bone marrow MRD negativity pre-HSCT had better outcomes (LFS 83%, OS 92%) than those with persistent MRD pre-HSCT (LFS 41%, OS 64%, P < 0·0001) or post-HSCT (LFS 35%, OS 55%, P < 0·0001). Patients with B-other ALL had more relapses (CIR 50%, LFS 41%) than T-ALL and the main precursor-B subtypes including BCR-ABL1, KMT2A (MLL), ETV6-RUNX1 (TEL-AML1) and hyperdiploidy >50. A Cox multivariate regression model for LFS retained both B-other ALL subtype (hazard ratio 4·1, P = 0·0062) and MRD persistence post-HSCT (hazard ratio 3·9, P = 0·0070) as independent adverse prognostic variables. Persistent MRD could be used to direct post-HSCT therapy.