Acute Lymphoblastic Leukemia Treatment Protocols Research Articles

IL16 and factor V gene variations are associated with asparaginase-related thrombosis in childhood acute lymphoblastic leukemia patients.

Aim: We previously conducted exome-wide association study in acute lymphoblastic leukemia patients and identified association of five SNPs with asparaginase-related thrombosis. Here we aimed to replicate these findings in an independent patient cohort and through analyses in vitro. Patients & methods: SNPs located in IL16, MYBBP1A, PKD2L1, RIN3 and MPEG1 genes were analyzed in patients receiving Dana-Farber Cancer Instituteacute lymphoblastic leukemia treatment protocols 05-001 and 11-001. Thrombophilia-related variations were also analysed. Results: IL16 rs11556218 conferred higher risk of thrombosis and higher in vitro sensitivity to asparaginase. The association was modulated by the treatment protocol, risk group and immunophenotype. A crosstalk between factor V Leiden, non-O blood groups and higher risk of thrombosis was also seen. Conclusion: IL16 and factor V Leiden variations are implicated in asparaginase-related thrombosis.

Chemotherapy delays in children with acute lymphoblastic leukemia might influence the outcome of treatment

Introduction: Acute lymphoblastic leukemia (ALL) is one of the most commonly occurring cancers among children with one of the highest survival rates, thanks to its very strict treatment protocol. In this paper, the impact of delays in treatment during the induction phase was assessed. Material and methods: Retrospective single center analysis of 127 patients treated between years 2003 and 2015 was performed. Patients were categorized by their respective gender, age, leukemia variant, risk group and chemotherapy protocol used. The delays were measured using protocol milestones as reference points. The associations between treatment delay intervals and event-free survival (PFS) or overall survival (OS) were evaluated using Kaplan-Meier curves and univariate Cox proportional hazards regression models. Results: Delays in treatment which occurred before the 8th day were associated with a 30% increase in the risk of death ( p < 0.01) and a 33% increase in the risk of relapse or death ( p < 0.01). The influence of delays after the 8 th day was statistically insignificant. Delays were proven to have the most influence on outcome in the high-risk group, especially before the 8 th day. Conclusions: The ALL treatment protocols should be strictly followed as any delay may lead to worse patients’ survival.

Genetic basis of clinical variants of chemotherapy toxicity in children with acute lymphoblastic leukemia (literature review)

Inspite of great successes in treatment and high incidence of surveillance in pediatric acute lymphoblastic leukemia (ALL), patients are addicted to many drugs adverse events, which sometimes indicate to decrease the dose or even cytotoxic drug interruption with following risk of secondary disease relapse. Besides, researches found significant inter-individual variability of drugs toxicity and disease outcome. This fact specify a role of pharmacogenetics (PGx) in genetic polymorphism revealing in gene-candidates for treatment optimization. Global wide initiated studies of correlation analysis between genetic polymorphism and toxicity effects of ALL treatment in different ethnic groups of patients. In Russia such studies are rare. In the current review we present annotations of gene-candidates of drugs with highest degree of proof their role in different types of clinical toxicity variants and recommendations for following PGx use in individualization of treatment protocols for pediatric ALL.

Cost of Pediatric Acute Lymphoblastic Leukemia Care in the Current Treatment Era

Introduction: Acute lymphoblastic leukemia (ALL) is the most common malignancy of childhood, with a current incidence of 3,000 cases annually. Incremental alterations in treatment over time have resulted in overall survival rates that now exceed 90%. Although minor differences exist between ALL treatment protocols from different cooperative groups, risk-stratified treatment for ALL is generally standard across the country. As more has been understood about ALL biology and outcomes, treatments have been further risk stratified to optimize outcomes for higher risk individuals while minimizing toxicities for those with more favorable disease characteristics. With the improvements in outcome for ALL, cost of care is a critical component and financial toxicity for patients and society requires evaluation.Methods: Using commercial insurance data from the OptumLabs ® Data Warehouse, a cohort of 1941 ALL patients was identified, aged 1-30 years and diagnosed between 2000 and 2017 in the United States. ALL diagnosis was confirmed based on ICD-9 and ICD-10 diagnostic codes, in combination with bone marrow and lumbar puncture procedure codes within 14 days of diagnosis. Individuals were followed up to 36 months from diagnosis. Mean monthly and cumulative costs were computed for the initial 8 months of therapy and for 36 months from diagnosis, as were mean number of inpatient and outpatient days. Costs were further broken down by the types of services provided. All results were stratified by age group (1-9 years, 10-12 years, ≥13 years) as a proxy for risk group, with the younger group most consistent with standard risk disease and the older groups indicating high risk and very high risk disease, respectively.Results: Among the 1941 identified ALL patients (1-9 years, 1233; 10-12 years, 162; ≥13 years, 546), 44% were female, 51% were white, median age at diagnosis was 6 years (interquartile range 3-14 years) and 941 of enrolled patients had continuous data through 36 months. Mean cost of care over the approximate 3 years of therapy was $537,000, with approximately 58% of costs incurred within the initial intensive 8 months of therapy. Mean cost was highest among the ≥13 year age group, both for the initial 8 months of therapy ($487,000, 95% CI $449,300-530,400)), as well as over the 36 months following diagnosis ($850,000, 95% CI $778,400-937,100) (Figure). This was reflective of the highest mean number of inpatient days among the ≥13 year age group (88.1 days over 36 months, 95% CI 82.1-94.9) compared to the 10-12 year group (73.2 days, 95% CI 64.3-85.1) and the 1-9 year group (47.5 days, 95% CI 45.2-50.9). Mean number of outpatient visits over 36 months was not significantly different between 1-9 and 10-12 year age groups but was significantly higher among the ≥13 year age group compared with the 1-9 year group. Thirty-six month survival varied by age group and was highest among the 1-9 year group (95.9%, 95% CI 94.6-97.2) compared with the 10-12 year group (90.5%, 95% CI 85-4-95.8) and the ≥13 year group (79.6%, 95% CI 75.8-83.6).Conclusions: This robust real-world cost analysis shows for the first time that the average cost of ALL care in the current treatment era, including inpatient and outpatient data, is more than $500,000. We showed that the cost of care is highest among the oldest pediatric age group, indicating increasing cost with increased therapeutic intensity. This study provides a valuable benchmark that can be used to analyze the financial toxicity of ALL therapy on patients and families and can be re-assessed over time as novel therapeutics are introduced into ALL therapy. [Display omitted] DisclosuresNo relevant conflicts of interest to declare.

Treatment of acute lymphoblastic leukemia in children by ALL IC-BFM 2002 protocol: results of multicenter retrospective study

By the whole history of pediatric acute lymphoblastic leukemia (ALL) treatment protocols development, one of the World ideologist of original science-based therapeutic approaches was German group BFM (Berlin–Frankfurt–Münster). It is not surprisingly that modern ALL treatment protocols, developed by BFM group are high-effective and use in many countries. Understanding the probability of recovery of overwhelming ALL patients majority treated by ALL IC-BFM 2002 protocol, the Scientific-Practical Board of Ministry of Health of Russia in 2020 adopted a protocol as clinical recommendation for pediatric ALL treatment (ID:529).It the current issue BFM ALL treatment protocols evolution is presented and first Russian multicenter experience in pediatric ALL treatment by ALL IC-BFM 2002 protocol. It was 408 pediatric and adolescents patients with primary ALL included the study. All of them were treated by ALL IC-BFM 2002 protocol from 01.11.2003 to 12.05.2021. Survival rate was estimated on 01.06.2021.ALL IC-BFM 2002 demonstrated a high efficiency in multicenter retrospective study. 15-year event-free survival was 83.7 ± 2.1 %, relapsefree survival – 88 ± 1.8 % and overall survival – 93.4 ± 1.4 %. So, ALL IC-BFM 2002 protocol could be realized in Russian clinics and give results similar to world’s leading medical centers.

Are there regional variations in the presentation of childhood leukemia?

Introduction: Treatment of childhood acute lymphoblastic leukemia (ALL) is based on risk stratification. This study aimed to assess the agreement between risk group classifications in the different childhood ALL treatment protocols used in a referral hospital in southern Brazil. Methods: We retrospectively reviewed the medical records of patients aged 1 to 18 years with B-cell ALL treated at a hospital from January 2013 to April 2017. Agreement between risk classifications was assessed by the kappa coefficient. Results: Seventy-five patients were analyzed. There was poor agreement between risk stratification by GBTLI 2009 and BFM 95 protocols (kappa=0.22; p = 0.003) and by GBTLI 2009 and IC-BFM 2002 protocols (kappa=0.24; p = 0.002). Risk group distribution was 13.3% for low risk, 32.0% for intermediate risk, and 54.7% for high risk based on stratification by the GBTLI 2009 protocol, and 28.0% for low risk, 42.7% for intermediate risk, and 29.3% for high risk based on stratification by the IC-BFM 2002 protocol. Overall survival was 68.6%. Conclusion: This study provides numerous points to ponder about the treatment of leukemia in Brazil. The percentage of patients classified as high risk in our sample was higher than that reported in the international literature. This difference, however, had no impact on overall survival, which was shorter than that reported in the international literature.

Immunophenotypic and Cytogenetic Characteristics of B Cell Acute Lymphoblastic Leukaemia (ALL). the Tawam Hospital (tertiary referral centre UAE) Experience

Acute Lymphoblastic Leukaemia (ALL) is an aggressive malignant lympho-proliferative neoplasm. Although excellent results are seen in paediatric population the same does not hold true in the adult population. In this retrospective study we looked at the patient characteristics of B cell ALL at Tawam hospital which is a tertiary care referral hospital for cancer therapy in the United Arab EmiratesMethods: Tawam hospital tumour registry was used to identify patients diagnosed with ALL aged 15 years and above between January 2010 till June 2017. Medical records were reviewed to collect data about age, sex, presenting hemogram, immuno-phenotyping, karyotype and outcome.Results: Seventy patients were identified with diagnosis of ALL in the defined period. Sixteen (23 %) patients had diagnosis of T cell ALL. Fifty four (77%) patients had B cell ALL. The median age was 26 years (range 15-71 years). Male to female ratio was 2.85:1. T cell ALL patients were excluded from further analysis.Immuno-phenotypically 29 patients (54 %) were CD 20 positive ALL (> 20 % CD 20 expression) while the other 25 (46%) were CD 20 negative ALL. The median white blood count (WBC) at presentation was 7000 (range 1 to 495 thousand) per millilitre for CD 20 positive ALL while the median WBC was 12000 (range 1-240 thousand) per millilitre for CD 20 negative cohort.Cytogenetic and/or molecular diagnostics showed the presence of Philadelphia chromosome or BCR-ABL positivity in nine patients with CD 20 positive ALL (31 %) while only 4 patients (13%) with CD 20 negative ALL were positive for BCR-ABL. (Table 1)Five patients refused therapy and were lost to follow up after diagnosis. Five patients died of therapy related complications in complete remission (CR) while one patient developed secondary malignancy (Acute myeloid leukaemia and expired). Fifteen patients are in CR1 and in continuous follow up while another twelve patients have been lost to follow up while in CR1. Sixteen patients had either primary refractory or relapsed disease. Ten (62 %) of those had CD 20 positivity while the rest six (38%) were CD 20 negative.Conclusion: In our experience more than half (54 %) of B cell ALL had a CD 20 positive immuno phenotype. Patients with CD 20 positive ALL had a lower median WBC at presentation as compared to the CD 20 negative cohort. Of greater interest is the higher rate of Philadelphia chromosome positivity in CD 20 positive observed in CD 20 positive cohort as compared to CD 20 negative cohort (31% versus 13 %). Patients with CD 20 appear to have a higher rate of relapsed refractory disease (62% versus 38%).CD 20 expression in ALL has been reported as ranging from 30 to 60 %. Similarly there has been controversy of CD 20 positive disease being associated with poor patient outcome. The majority of the previous reports either exclude Philadelphia chromosome positive disease or report no significant difference.Even though CD 20 antibodies have been used previously with variable results, the large disparity in the treatment protocols for ALL for adults makes it difficult to choose a standard approach. Similarly the role of humanized CD 20 anti-bodies like Obinutuzumab and ofatumumab remains undefined.Although our cohort has a big disparity in Philadelphia chromosome positivity between the two sub groups the small sample size makes it difficult to make a definite conclusion and these results should be validated in a larger cohort. [Display omitted] DisclosuresAlam:BMS: Honoraria; Biologix: Honoraria.

Pediatric acute lymphoblastic leukemia treatment protocols improvement: emphasis on minimal residual disease

Treatment of acute lymphoblastic leukemia (ALL) in children during the last 50 years has changed significantly, which has increased the survival of patients from 10–15 % in the early 60s to 80–85 % by the mid-2000s. Such results have been achieved through the development of new polychemotherapy regimens, the introduction of neuroleukemia prophylaxis, the strengthening of standard chemotherapy by increasing the dose and / or frequency of chemotherapeutic drugs administration, and the definition of criteria for patient stratification into prognostic risks groups and the development of principles of risk-adopted therapy.However, inspite of the overall success of pediatric acute lymphoblastic leukemia therapy, some variants of acute lymphoblastic leukemia associated with poor prognosis, especially acute lymphoblastic leukemia with BCR-ABL1 and MLL rearrangements. Besides the prolonged persistence of minimal residual disease is also an unfavorable prognostic factor requiring therapy intensification.In the current issue we present the main steps in the evolution of programmed chemotherapy of children with acute lymphoblastic leukemia. Great attention was paid for modern risk-stratifying criteria with an emphasis on minimal residual disease.

National Italian Delphi panel consensus: which measures are indicated to minimize pegylated-asparaginase associated toxicity during treatment of adult acute lymphoblastic leukemia?

BackgroundL-asparaginase (L-ASP) is a key component of acute lymphoblastic leukemia (ALL) treatment, but its use in clinical practice raises challenges to clinicians due to a relatively high incidence of drug-related adverse events, mainly in adult patients. In the past years the use of ASP in adult population has been mainly limited due to a poor knowledge of its safety profile and to an approximate management of ASP-related toxicity. Recently the development of pediatric-inspired treatment protocols for adult ALL has led to a wider use of ASP and since 2010 in Italy three national treatment protocols including Pegylated asparaginase (Peg-ASP) have been sequentially developed for adolescents, young adults and adults with Philadelphia-negative (Ph-) ALL.MethodsWith the aim to better understand the approach adopted in Italian centers for the management and prevention of Peg-ASP toxicity in adult ALL and to provide practical, consensus-based recommendations, a board of 6 Italian clinicians, with known expertise in adult ALL, designed 41 consensus statements on current challenges on the management of Peg-ASP associated toxicity. A group of 19 clinical experts in the field then rated these statements using the 5-point Likert-type scale (1 = strongly disagree; 5 = strongly agree).ResultsThe main Peg-ASP related issues identified by the board included: 1) clinician’s attitudes; 2) toxicity profile; 3) hypersensitivity reactions; 4) hepatic toxicity; 5) hepatic and/or metabolic toxicity; 6) hemorrhagic/thrombotic toxicity; 7) pancreatitis; 8) metabolic toxicity management and prevention; 9) activity levels monitoring. Overall, participants agreed on most statements, except those addressing the potential contraindications to the treatment with Peg-ASP, such as patients with a diagnosis of chronic liver disease or the subsequent administrations of the drug in patients who had previously developed chemical pancreatitis or severe metabolic toxicity. Participants agreed that adult patients with ALL should receive Peg-Asp because this drug is essential to improve treatment results.ConclusionsThe panel agreed that a critical evaluation of specific risk factors for each patient is crucial in order to reduce the risk of adverse events and specific advices in the management of Peg-ASP toxicities are reported.

Functional and structural evaluation of the antileukaemic enzyme L-asparaginase II expressed at low temperature by different Escherichia coli strains.

Acute lymphoblastic leukaemia (ALL) affects lymphoblastic cells and is the most common neoplasm during childhood. Among the pharmaceuticals used in the treatment protocols for ALL, Asparaginase (ASNase) from Escherichia coli (EcAII) is an essential biodrug. Meanwhile, the use of EcAII in neoplastic treatments causes several side effects, such as immunological reactions, hepatotoxicity, neurotoxicity, depression, and coagulation abnormalities. Commercial EcAII is expressed as a recombinant protein, similar to novel enzymes from different organisms; in fact, EcAII is a tetrameric enzyme with high molecular weight (140kDa), and its overexpression in recombinant systems often results in bacterial cell death or the production of aggregated or inactive EcAII protein, which is related to the formation of inclusion bodies. On the other hand, several commercial expression strains have been developed to overcome these expression issues, but no studies on a systematic evaluation of the E. coli strains aiming to express recombinant asparaginases have been performed to date. In this study, we evaluated eleven expression strains at a low temperature (16°C) with different characteristics to determine which is the most appropriate for asparaginase expression; recombinant wild-type EcAII (rEcAII) was used as a prototype enzyme and the secondary structure content, oligomeric state, aggregation and specific activity of the enzymes were assessed. Structural analysis suggested that a correctly folded tetrameric rEcAII was obtained using ArcticExpress (DE3), a strain that co-express chaperonins, while all other strains produced poorly folded proteins. Additionally, the enzymatic assays showed high specific activity of proteins expressed by ArcticExpress (DE3) when compared to the other strains used in this work.

Influence of minimal residual disease by multiparametric flow cytometry at day 15 of induction in risk stratification of children with B-cell acute lymphoblastic leukemia treated at a referral hospital in southern Brazil.

BackgroundThe minimal residual disease (MRD) is the most important prognostic factor for acute lymphoblastic leukemia (ALL) in children. This study aimed to investigate the influence of detecting the MRD by the multiparametric flow cytometry (MFC) at day 15 (D15) of the induction on the analysis of the risk group classifications of the different childhood ALL treatment protocols used in a referral hospital in southern Brazil.MethodWe retrospectively reviewed the medical records of patients with B-cell ALL, aged 1 to 18 years, treated at a hospital from January 2013 to April 2017.Main resultsSeventy-five patients were analyzed. Regarding the MRD by the MFC at D15, the analyses showed statistical significance when the MRD was grouped into three categories, < 0.1%, 0.1–10%, and > 10%, with the following distribution: 30.7%, 52.0%, and 17.3%, respectively. There was a significant association between D15 MRD-MFC < 0.1% and the likelihood of dying or relapsing and between D15 MRD-MFC > 10% and the likelihood of dying or relapsing. The cumulative hazard ratio for the relapse of patients with D15 MRD-MFC < 0.1%, 0.1–10%, and > 10% was 19.2%, 59.8%, and 80.1%, respectively.ConclusionOur analysis suggests D15 MRD-MFC < 0.1% as a cut-off point for patients with more favorable outcomes and that the MRD at D15 in risk classifications is particularly useful for the stratification of patients with a more favorable prognosis.

Pediatric Preclinical Testing Consortium Evaluation of the Novel Anti-Microtubule Drug E7130 in Xenograft Models of Early T-Cell Precursor Acute Lymphoblastic Leukemia

Introduction: While children diagnosed with acute lymphoblastic leukemia (ALL) experience close to a 90% likelihood of cure, the outcome for certain high-risk pediatric ALL subtypes as well as adult ALL remains poor. Several standard-of-care drugs used in multi-agent treatment protocols for ALL (including vincristine, daunorubicin and methotrexate) are substrates for the ATP-dependent drug efflux pump P-glycoprotein (P-gp), encoded by the ABCB1 gene, although there are limited reports of ABCB1 gene expression being associated with poor outcome in ALL (Carrillo et al, Hematol. 22:286-91, 2017). A previously identified high-risk subtype of T-ALL (early T-cell precursor ALL, ETP-ALL) characterized by poor early response to conventional induction treatment, expresses significantly higher levels of the ABCB1 gene compared with typical T-ALL (1.97-fold; false discovery rate=0.0026; P=0.00029; Zhang et al, Nature 481:157-63, 2012). E7130 is a novel anti-microtubule drug that is a less potent substrate for P-gp compared with other anti-microtubule drugs such as vincristine, and it has shown significant preclinical activity against patient-derived xenograft (PDX) models of adult malignancies. Therefore, it was of interest for the Pediatric Preclinical Testing Consortium (PPTC) to test the in vivo activity of E7130 against its PDX models of pediatric ETP-ALL. Methods: ABCB1 mRNA expression in ALL PDXs was quantified by RNAseq (https://pedcbioportal.org) and qRT-PCR. P-gp protein expression was assessed by immunoblotting, while its activity was measured by the Rhodamine-123 efflux assay in the absence or presence of the P-gp inhibitor tariquidar. E7130 and vincristine were evaluated in vivo against 6 ETP-ALL PDXs. Each PDX was inoculated into 6-8 immune-deficient (NSG) mice per treatment group (2-5 x 106 cells/mouse). Engraftment and drug responses were evaluated by enumerating the proportion of human CD45+ cells in the peripheral blood (%huCD45+) at weekly intervals. E7130 was tested at 2 dose levels (0.09 and 0.135 mg/kg IV), while vincristine was evaluated at 1 mg/kg IP. Both drugs were administered weekly x 3. Events were defined as the %huCD45+ ≥25%. Drug efficacy was assessed by event-free survival of treated (T) and control (C) groups by T-C, T/C and stringent objective response criteria (Houghton et al, Pediatr Blood Cancer 49:928-40, 2007). Results: RNAseq analysis of the 6 ETP-ALL PDXs in the PPTC panel of 90 pediatric ALL PDXs revealed 3 with high ABCB1 expression (FPKM 7.1-13.6; ETP-2, -3 and -6) and 3 with low expression (FPKM 0-0.15; ETP-1, -4 and -5), which was confirmed by qRT-PCR and immunoblotting. Moreover, high levels of tariquidar-sensitive Rhodamine-123 efflux activity were confirmed in the 2 high ABCB1 expressing PDXs tested (ETP-2 and -3). E7130 was generally well tolerated in NSG mice, with maximum average weight loss of 2.7-17.6% in the groups treated with the highest dose compared with 3.2-12.7% in the vincristine treated groups. E7130 (0.09 mg/kg) significantly (P&lt;0.05) delayed the progression of all 6 PDXs (T-C 10.5-41.3 days, T/C 1.8-5.9) and elicited objective responses in 2/6 PDXs (1 Complete Response, CR; 1 Maintained CR, MCR). The higher dose of E7130 (0.135 mg/kg) significantly delayed the progression of all 5 evaluable PDXs (T-C 18.1-49.5 days, T/C 2.3-8.8) and elicited 4 objective responses (1 CR, 3 MCRs). In contrast, vincristine significantly delayed the progress of 5/6 PDXs (T-C 3.5-37.7 days, T/C 1.3-6.6) and elicited 2 objective responses (1 CR, 1 MCR). When the PDXs were stratified around ABCB1 expression there was a trend for reduced vincristine activity against high (T-C 3.5-18.0 days, T/C 1.3-2.1) versus low (T-C 21.4-37.7 days, T/C 2.7-6.6) expressing PDXs. In contrast, the activity of E7130 was maintained regardless of ABCB1 expression at both the 0.09 mg/kg dose (low ABCB1, T-C 17.6-41.3 days, T/C 2.4-5.9; high ABCB1, T-C 10.5-32.0 days, T/C 1.8-3.0) and the 0.135 mg/kg dose (low ABCB1, T-C 30.7-46.2 days, T/C 3.5-8.8; high ABCB1, T-C 18.1-49.5 days, T/C 2.9-4.0). Conclusions: E7130 exhibits significant in vivo activity against pediatric ETP-ALL PDXs, regardless of their levels of ABCB1 expression. Our results support further evaluation of E7130 in pediatric ALL to determine whether it represents an alternative treatment option in ALL with high ABCB1 expression. (Supported by NCI Grants CA199000 and CA199922) Disclosures No relevant conflicts of interest to declare.

Targeting Critical Kinases and Anti-Apoptotic Molecules Overcomes Steroid Resistance in Infant MLL-Rearranged Leukemia

Acute lymphoblastic leukemia (ALL) with rearrangement of the mixed-lineage leukemia (MLL) gene frequently affects infants and is associated with a poor prognosis. Standard treatment protocol for infant MLL-rearranged ALL (MLL-ALL) includes glucocorticoids (GCs). However, resistance to GCs remains a major problem. Therefore, it is important to find new treatment strategies that overcome GC resistance in MLL-ALL. To identify novel therapeutic targets to overcome GC resistance in MLL-ALL, we compared transcriptional profiles of normal cord blood CD34+CD38- hematopoietic stem and progenitor cells and GC-resistant infant MLL-ALL leukemia-initiating cells (LICs). We found enrichment of the Src family kinases (SFKs) and Fms-like tyrosine kinase 3 (FLT3) signaling pathways in the LICs. We hypothesized that activation of these kinases may contribute to GC resistance in MLL-ALL cells. Using our previously developed infant MLL-ALL patient-derived xenograft (PDX) models (Aoki et al., Blood, 2015), we recapitulated human GC-resistance in vivo, characterized by increased hCD45+ chimerism in the peripheral blood after treatment with dexamethasone (% peripheral blood human MLL-ALL at pre-treatment: 34.1±5.2% vs. post treatment 51.3±6.6%, n=26). In order to investigate if inhibition of SFKs and FLT3 can overcome GC-resistance, we treated the MLL-ALL PDX models with our previously developed FLT3-SFK multiple kinase inhibitor RK-20449 (Saito et al., Science Translational Medicine, 2013). Combination treatment with dexamethasone and RK-20449 successfully eliminated human MLL-ALL cells from the peripheral blood (dexamethasone alone: 47.2±7.2% vs. combination: 5.6±2.8% hCD45+ cells, p=6.91E-7), bone marrow (dexamethasone alone: 72.2±4.6% vs. combination: 19.5±4.8% hCD45+ cells, p=1.79E-10), and spleen (dexamethasone alone: 52.6±4.8% vs. combination: 11.7±3.5% hCD45+ cells, p=3.75E-9). In addition, combination treatment eliminated infiltrated MLL-ALL from kidney and liver of the MLL-ALL PDX models. Bcl-2 homology domain 3 (BH3) profiling demonstrated that MLL-ALL cells resistant to RK-20449 treatment were dependent on the anti-apoptotic Bcl-2 protein for their survival. Additional inhibition of Bcl-2 by ABT-199 led to complete elimination of MLL-ALL cells in vitro and in vivo in all MLL-ALL patient cases (Figure1). Taken together, in this study we demonstrated that inhibition of SFKs and FLT3 by RK-20449 overcomes GC-resistance in MLL-ALL. Further, we identified Bcl-2 dependence as a mechanism of treatment resistance in MLL-ALL. Therefore, we believe that the combined inhibition of kinase and anti-apoptotic pathways may lead to effective treatment options for highly resistant infant MLL-ALL. Aoki, et al., Identification of CD34+ and CD34- leukemia-initiating cells in MLL-rearranged human acute lymphoblastic leukemia. Blood, 2015: p. 967-980. Saito, Y., et al., A Pyrrolo-Pyrimidine Derivative Targets Human Primary AML Stem Cells in Vivo. Science Translational Medicine, 2013: p. 1-15. Disclosures No relevant conflicts of interest to declare.

The changing burden of long-term health outcomes in survivors of childhood acute lymphoblastic leukaemia: a retrospective analysis of the St Jude Lifetime Cohort Study

Treatment for childhood acute lymphoblastic leukemia has evolved over the past five decades, with moderation of traditional chemotherapy and radiotherapy and the introduction of targeted immune-based and cellular-based therapies. The affect of these changes on late health outcomes has not been assessed. Using data from the The St Jude Lifetime (SJLIFE) Cohort, we aimed to characterise the magnitude of morbidity and patterns of late health outcomes among survivors of childhood acute lymphoblastic leukaemia treated over time. The St Jude Lifetime (SJLIFE) Cohort is a retrospective cohort study with prospective follow-up and ongoing data accrual designed to facilitate longitudinal, clinically-based assessment of health outcomes among survivors of paediatric malignancies. 980 survivors included in this analysis were diagnosed with paediatric acute lymphoblastic leukaemia at St Jude Children's Research Hospital (SJCRH) between Aug 28, 1963, and July 19, 2003, were aged 18 years old and older at enrolment, had a minimum follow-up of 10 years after diagnosis, and completed an initial on-campus SJLIFE assessment as of data cutoff (June 30, 2015). 272 community control participants, matched to survivors on 5-year age blocks in each sex, were recruited for comparison. Cumulative chemotherapy and radiation dose exposures and major medical events during and after therapy were retrieved from the medical records of the survivors. History or physical examination, laboratory analysis, physical fitness, and neurocognitive testing were done. Health conditions were graded according to a modified version of the Common Terminology Criteria for Adverse Events. Neurocognitive domains of attention (Trial Making Test Part A and Conner's Continuous Performance Test-II) and executive function (Trail Making Test Part B, Controlled Oral Word Association Test, and Wechsler Adult Intelligence Scale-III Digit Span Test Backward) were measured and age-adjusted Z scores were calculated. Mean cumulative count was used to calculate the age-standardised cumulative burden of health conditions over time. This cohort study is registered at ClinicalTrials.gov, number NCT00760656. 980 survivors of acute lymphoblastic leukaemia (50% women, median age at diagnosis 5 years [IQR 3·1-9·1 years], and median time from diagnosis of 30·0 years [22·7-36·3]) had a median age of 35·8 years (29·4-42·9) at assessment compared with 35·1 years (28·7-42·6) for 272 controls. Survivors had significantly more growth hormone deficiency, hypogonadism, and neuropathy than controls. By age 30 years, survivors of acute lymphoblastic leukaemia had, on average, 5·4 (95% CI 5·1-5·8) grade 1-4 health conditions, including 3·2 (2·9-3·4) grade 2-4 health conditions, compared with 2·0 (CI 1·7-2·2) grade 1-4 and 1·2 (1·03-1·4) grade 2-4 health conditions among controls. The cumulative burden of grade 2-4 health conditions involved multiple organ systems for survivors treated on protocols between 1962-91, but after elimination of cranial radiotherapy for children with acute lymphoblastic leukaemia, conditions now predominately include musculoskeletal and endocrine disorders for survivors on protocols between 1991-2007. Although changes in paediatric acute lymphoblastic leukaemia treatment protocols have improved overall survival, the burden of late morbidity remains high for these patients. We show that the pattern of late toxic effects has markedly changed over time, with survivors having a reduction in health conditions that are immediately life-threatening, however, maintaining health status and quality of life for survivors of paediatric acute lymphoblastic leukaemia requires continued medical surveillance, counselling, and lifestyle modifications. US National Cancer Institute and the American Lebanese Syrian Associated Charities.

No evidence that G6PD deficiency affects the efficacy or safety of daunorubicin in acute lymphoblastic leukemia induction therapy.

Anthracyclines are used in induction therapy of pediatric acute lymphoblastic leukemia (ALL) and are known to generate oxidative stress; whether this translates into enhanced antileukemic activity or hemolytic effects in patients with glucose-6-phosphate dehydrogenase (G6PD) deficiency is unknown. Among 726 pediatric patients with newly diagnosed ALL treated at St. Jude Children's Research Hospital, 22 had deficient G6PD activity. We compared the prevalence of positive minimal residual disease (MRD) ≥1% at Day 15/Day 19 of induction or ≥0.01% at Day 42/Day 46 (end of induction) and the number of red blood cell (RBC) transfusions after daunorubicin in induction between patients with or without G6PD deficiency, adjusting for ALL risk group, treatment protocol, age, and gender. There was no difference in Day 15/19 (P=1) or end of induction MRD (P=0.76) nor in the number of RBC transfusions (P=0.73); the lack of association with MRD was confirmed in a dataset of 1192 newly diagnosed male patients enrolled in a Children's Oncology Group trial (P=0.78). We found no evidence that G6PD deficiency affects daunorubicin activity during induction treatment for ALL.

Pharmacogenomic and Pharmacotranscriptomic Profiling of Childhood Acute Lymphoblastic Leukemia: Paving the Way to Personalized Treatment.

Personalized medicine is focused on research disciplines which contribute to the individualization of therapy, like pharmacogenomics and pharmacotranscriptomics. Acute lymphoblastic leukemia (ALL) is the most common malignancy of childhood. It is one of the pediatric malignancies with the highest cure rate, but still a lethal outcome due to therapy accounts for 1–3% of deaths. Further improvement of treatment protocols is needed through the implementation of pharmacogenomics and pharmacotranscriptomics. Emerging high-throughput technologies, including microarrays and next-generation sequencing, have provided an enormous amount of molecular data with the potential to be implemented in childhood ALL treatment protocols. In the current review, we summarized the contribution of these novel technologies to the pharmacogenomics and pharmacotranscriptomics of childhood ALL. We have presented data on molecular markers responsible for the efficacy, side effects, and toxicity of the drugs commonly used for childhood ALL treatment, i.e., glucocorticoids, vincristine, asparaginase, anthracyclines, thiopurines, and methotrexate. Big data was generated using high-throughput technologies, but their implementation in clinical practice is poor. Research efforts should be focused on data analysis and designing prediction models using machine learning algorithms. Bioinformatics tools and the implementation of artificial i Lack of association of the CEP72 rs924607 TT genotype with intelligence are expected to open the door wide for personalized medicine in the clinical practice of childhood ALL.

Implementation of a multifaceted program to improve uptake of guideline recommendations for adolescent and young adults (AYAs) with acute lymphoblastic leukemia (ALL).

50 Background: ALL is one of the most common malignancies in the AYA population (age 15-39) and is associated with poor survival in AYAs when compared with children. There is compelling evidence demonstrating a survival benefit for AYAs treated with pediatric regimens vs adult regimens, and guidelines from the National Comprehensive Cancer Network now recommend consideration of pediatric inspired treatment. However, uptake has been suboptimal, with only 25%-35% of AYAs with ALL receiving a pediatric regimen in the U.S. There are several potential barriers to uptake, including lack of knowledge and guidance about the recommendations. For this study, we implemented and evaluated a multi-faceted program to improve uptake in a large health care system, Kaiser Permanente Southern California (KPSC), with 14 medical centers across the region. Methods: The program was initiated regionally in 2013 across all 14 medical centers. Content included education of clinical leaders, rapid identification of newly diagnosed AYA ALL patients by the hematopathology team, and guidance and support from a pediatric oncologist for adult oncology teams treating AYA ALL patients emphasizing a pediatric regimen when appropriate. We subsequently identified AYA ALL patients diagnosed and treated between 2012-2016. A detailed chart review was conducted to determine treatment regimens prior to implementation of the program and post-implementation. Results: We identified 58 patients, 11 in the period prior to implementation and 47 post-implementation. Overall, 18% of patients in the pre-intervention period were treated on a pediatric regimen vs. 77% post-implementation. We found an increasing trend over time in the post-intervention period, with 46% receiving a pediatric protocol in 2013, 64% in 2014, 92% in 2015, and 100% in 2016. Conclusions: We were successful at increasing the proportion of eligible patients who received pediatric protocols for treatment of AYA ALL. Implementing a multi-faceted approach to improve care for this rare condition was feasible and acceptable to oncology clinicians across the region, with potential for large-scale scale-up and spread.

RUSSIAN-BELARUSIAN MULTICENTER GROUP STANDARD GUIDELINES FOR CHILDHOOD ACUTE LYMPHOBLASTIC LEUKEMIA FLOW CYTOMETRIC DIAGNOSTICS

Background. Flow cytometry is one of the key technologies for acute lymphoblastic leukemia (ALL) diagnostics. Nevertheless lack of technological standards hampers implementation of immunophenotyping data in treatment protocols. Objective: development of harmonized guidelines for flow cytometric diagnostics of childhood ALL. Materials and methods. Three reference laboratories of the immunophenotyping group “Moscow–Berlin” took part in the development and standardization of approaches to the cytometric determination of the minimal residual disease. The sequence of steps for staining with monoclonal antibodies, selection of reagents for immunophenotyping, flow cytometer adjustment algorithms were discussed. Results. We developed and implemented in multicenter setting the harmonized approach for immunophenotyping flow cytometric childhood ALL. Successful integration of this protocol in the multicenter group has shown good level of our approach reproducibility. Conclusion . These results will allow implementing diagnostic standards in stratification system of pediatric ALL treatment protocols of russianbelarusian multicenter group.

Early Nutrition Intervention Attenuates Weight Gain for Pediatric Acute Lymphoblastic Leukemia Patients in Maintenance Therapy.

Obesity following treatment of pediatric acute lymphoblastic leukemia (ALL) has become a significant long-term concern. Excessive weight gain often occurs during treatment, particularly during induction and the first 6 months of maintenance therapy, and it may be potentially modifiable. This retrospective study aimed to evaluate the impact of an early, 3-visit nutrition intervention on weight gain during maintenance therapy in ALL patients. Medical records of the intervention group were compared with historical controls who were treated on the same ALL treatment protocols during an earlier time period. Anthropometrics were collected throughout intensive therapy and at every monthly visit during the first 12 months of maintenance therapy. In total, 67 patients were evaluated (33 in the intervention group and 34 in the control group). After controlling for significant predictors of body mass index (BMI) z-scores in maintenance therapy-including higher BMI at diagnosis and weight gain throughout intensive therapy-the intervention group demonstrated more controlled weight gain during maintenance therapy (P<0.0001). A 3-visit nutrition intervention was effective in attenuating weight gain trends during ALL maintenance therapy.

Influence of BCL2L11 polymorphism on osteonecrosis during treatment of childhood acute lymphoblastic leukemia

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.